8th International OTEC Symposium

transcript

International

OTEC Symposium

27-29 January 2021 Cancun, Q. Roo. Mexico

Organized by:

ISBN: 978-607-9161-63-7.

8th International OTEC Symposium

Preface

The 8th International OTEC Symposium was held from January 27th through January 29th. Due to the current world wide circumstances, this event was organized to be entirely online. The Universidad de Caribe in Cancun, Quintana Roo, Mexico was the host organization. The symposium was organized by members of Thermal Gradient Strategy Line of the Mexican Center for Ocean Energy Innovation. Experts from different countries have met since 2013. Given the interest Mexico has shown because of its position in a favorable zone for the installation of OTEC plant; our country was invited to be the host of the 8th Symposium. Originally proposed like on site event in Cancun, Quintana Roo in October of 2020. However, it was held online in January 2021. Previous symposiums were held during the following years and locations: Hawaii, USA 2013, Netherlands 2014, South Korea 2015, Malaysia 2016, Reunion Island (France) 2017 Okinawa, Japan 2018, and Busan, South Korea 2019. A recognition has been granted each year called the Uehara Award. It is named after a technological precursor of OTEC. This year, the award was given to Dr. Tom Daniel from Hawaii, USA for his contribution to the utilization and application of OTEC technology. During this event, there were 5 keynotes, 35 expositions, and 15 posters, from the following participating countries: China, France, Germany, Japan, Malaysia, Mexico, Norway, Puerto Rico, South Korea, United Kingdom, and United States. The subjects presented at the 8th International OTEC Symposium:

OTEC Technology / Research Resource Assessment

Finance / Policy / Social Considerations

Economical and costs

Ongoing Projects

Environmental Considerations

Other Seawater Uses: Sea Water Air Conditioning (SWAC), Desalinated Water, Deep Ocean Water Applications (DOWA), etc.)

The Conference was held under the auspices of the Centro Mexicano en Innovación de Energía del Océano (CEMIE-O), Ocean Thermal Energy Association (OTEA), Executive Committee and Local Organizing Committee led by Universidad del Caribe, Institute of Marine Sciences and Limnology, UNAM, Institute of Engineering, UNAM and Universidad de Baja California Sur.

Dr. Miguel A. Alatorre Mendieta

Local Organizing Committee Chair: Dr. Miguel A. Alatorre Mendieta, Institute of Marine Sciences and Limnology, Universidad Nacional Autonoma de Mexico (UNAM), Mexico City, Mexico. Co-chair: Dra. Estela Cerezo Acevedo, Department of Basic Sciences and Engineering, Universidad del Caribe, Cancun, Q. Roo, Mexico. MSc. Juan F. Bárcenas Graniel, Department of Basic Sciences and Engineering, Universidad del Caribe, Cancun, Q. Roo, Mexico. Eng. Jessica G. Tobal Cupul, Department of Basic Sciences and Engineering, Universidad del Caribe, Cancun, Q. Roo, Mexico MSc. Alejandro García Huante, Institute of Engineering, UNAM, Mexico City, Mexico. Dr. Yandy Rodríguez Cueto, Institute of Engineering, UNAM, Mexico City, Mexico. MSc. Paola Garduño Ruiz, Institute of Engineering, UNAM, Mexico City, Mexico. MSc. Ricardo E. Hérnandez Contreras, Institute of Marine Science and Limnology, UNAM, Mexico City, Mexico. MSc. Madelein Galindo de La Cruz, Department of Basic Sciences and Engineering, Universidad Autónoma de Baja California Sur, La Paz, B. C. S. Mexico. MSc. Oscar Reséndiz Pacheco, Department of Basic Sciences and Engineering, Universidad Autónoma de Baja California Sur, La Paz, B. C. S. Mexico.

International Executive Committee

Dr. Miguel Ángel Alatorre Mendieta, Institute of Marine Sciences and Limnology, UNAM, Mexico. Dr. Hyeon Ju Kim, Korea Research Institute of Ships and Ocean Engineering, Korea Republic. Dr. Purnima Jalihal, National Institute of Ocean Technology, India. Dr. Luis A. Vega, University of Hawaii, United States. Dr. Albert S. Kim, University of Hawaii, United States Dr. Yasuyuki Ikegami, Saga University, Japan Benjamin Martin, Xenesys Inc., Japan. Dr. Berend Jan Kelute, BlueRise (All Seas Group), The Netherlands. Dr. Martin G. Brown, Ocean Energy Systems Limited & Aqualis Braemar, Aberdeen, United Kingdom. Dr. Sathiabama T. Thirugnana, UTM OTEC, Universiti Teknologi Malaysia. Dr. Song Zhang, National Ocean Technology Center, China. Dr. Thierry Bouchet, Naval Energies Group, France. Dr. Liu Weimin, Fiomarine (FIO, Shangai P-Nav Scientific Instruments Ltd.), China.

PROGRAM 8th International OTEC Symposium

8th International OTEC Symposium Time:GMT-5 Wednesday, January 27th

8:00 9:00 Registration

9:00 9:40 Opening Ceremony

Chair: Miguel Angel Alatorre

9:40 9:50 Break-time

Keynote 1

Dr. Purnima Jalihal

National institute of Ocean Technology Renewable Energy from Ocean-India

“Renewable Energy from Ocean-India”

Chair: Estela Cerezo

SESSION 1: Research Resource Assessment, Seawater Uses and Ongoing Projects Chairs: Jessica Tobal, Alejandro Garcia

IOS8MX039-SWU-R

Multiple deep sea water use in OTEC renewable power generation socio-economic variables and peculiarity

Masanori Kobayashi and Atsushi Watanabe

IOS8MX034-OO-R

OTEC-generated hydrogen for CO2 conversion into green hydrocarbons A. Bakar Jaafar, Mohd Khairi Abu Husain and Sathiabama T Thirugnana

IOS8MX006-OP-R

Recent Activity towards Combined Use of MW OTEC and Large- scale Seawater Industries on Kumejima

Benjamin Martin, Shin Okamura and Naoki Ota

IOS8MX014-RRA-R

Estimation of Ocean Thermal Energy Conversion (OTEC) Resources in Sabah, Malaysia

Sathiabama T. Thirugnana, Abu Bakar Jaafar, Takeshi Yasunaga, Tsutomu Nakaoka, Su-N.P. Suriyanti and Yasuyuki Ikegami

IOS8MX012-SWU-R

Investigating the performance of two ammonia-water compression/absorption combined refrigeration system using ocean thermal energy Zheng Hua, Dan Huab and Chengbin Zhanga

IOS8MX004-RRA-S

Spatial-temporal distribution of the OTEC Capacity Factor from SST data in Mexican Coasts

E. Paola Garduño-Ruiz, Yandy Rodríguez-Cueto , Alejandro García-Huante , Juan Francisco Bárcenas-Graniel , Jessica Guadalupe Tobal Cupul and Rodolfo

Silva-Casarín

Session 2: Research Resource Assessment, Seawater Uses and Ongoing Projects Chairs: Jessica Tobal, Alejandro Garcia

IOS8MX001-RRA-S

Comparative analysis of sea-surface temperature data for possible OTEC implementation in the Mexican Pacific Ocean

Alejandro García Huante, Yandy Rodríguez Cueto, Erika Paola Garduño Ruíz, Ricardo Hernández Contreras, Miguel Ángel Alatorre Mendieta and Rodolfo Silva Casarín

IOS8MX003-RRA-R

Ocean Thermal Energy Conversion – Flexible Enabling Technology for Variable Renewable Energy Integration in the Caribbean

R. J. Brecha, Katherine Schoenenberger, Masaō Ashtine, Randy Koon Koon

IOS8MX024-OT-S

Simulation of a SWAC System at the Baja California Sur Peninsula Juan Antonio Martínez Chavelas, Elizabeth Chávez Martínez, Oscar Reséndiz

Pacheco and Miguel Ángel Alatorre Mendieta

IOS8MX007-SWU-R

Island State Case Study of Coproduction of Ammonia and Freshwater Using Ocean Thermal Energy

C. B. Panchal and Kruti Goyal

IOS8MX011-SWU-R

Cost Reduction Opportunities for Deep-Sea Cold-Water Air Conditioning Systems (SWAC)

Caroline Le Floc’h, Olivier Langeard and Bruno Garnier

IOS8MX010-OO-R

OTEC and cold deep Ocean Water can save the Climate Peter Hovgaard and Lars Golmen

Poster Session 1 Chair: Yandy Rodríguez

IOS8MX005-EnvC-S

Characterization of seawater column between 0 to 1000-meter depth with physical,

chemical and biological parameters in Banderas Bay and Marias Islands in the Mexican Pacific Ocean for OTEC prospection.

Ricardo Efraín Hernández Contreras*, Miguel Ángel Alatorre Mendieta, Leonora Fernanda Mondragón Sánchez, Yandy Rodríguez Cueto, Erika Paola Garduño

Ruíz, Alejandro García Huante and Rodolfo Silva Casarín

IOS8MX009-RRA-S

Determination of suitable sites for OTEC Implementation in Mexican Coasts using a machine learning clustering algorithm

Sebastian A. Reyes-Romero, E. Mendoza and M. Robles

IOS8MX017-SC-S

Philosophy Gradients in the OTEC International Community. A Preliminary Mapping Armando Alonso Pérez Pérez

IOS8MX022-RRA-S

Technical Feasibility of Central OTEC in Diamante, Baja California Sur, as a Solution to the Great Energy Demand of the State

Marisol García Espinoza, César Ángeles Camacho, Oscar Reséndiz Pacheco, Madelein Galindo De la Cruz and Miguel Ángel Alatorre Mendieta

IOS8MX032-EnvC-S

Occurrences and Distribution of Microplastic in the Surface Water of Prospectively Constructed H-OTEC (Hybrid Ocean Thermal Energy Conversion) in Port Dickson, Malaysia

Azim Haziq Zainuddin, Ahmad Zaharin Aris, Fatimah Md Yusoff, Nur Amiera Kamarudin, Md Yaekub Ali, Syaizwan Zahmir Zulkifli, Ferdaus Mohamat Yusuffa, Natrah Fatin Mohd

Ekhsana, Mohd

14:25 14:30 First Day Closing

Time:GMT-5 Thursday, January 28th 8:30 9:00 Registration

9:00 9:33 Uehara Award Ceremony

Chair: Benjamin Martin

9:43 10:23 Keynote 2

Dr. Sanjayan Velautham Former CEO Sustainable Energy Development Authority Malaysia Renewable Energy in

Malaysia OTEC & Green Hydrogen Chair: Nora Leon

SESSION 3: OTEC Technology Chair: Nora Leon

IOS8MX021-OT-R

Experimental study of Open Cycle OTEC power module on laboratory scale Biren Pattnaik, Karthikeyan A, Anand Mani, Ashok Kumar, Sajeev KS,

Narasimha Rao, Prasad V.

10:48 11:03 IOS8MX018-OT-R

Novel, enhanced thermal conductivity heat exchanger for OTEC Meng Soon Chiong, Feng Xian Tan, Srithar Rajoo, Sathiabama T.

Thirugnana, Takeshi Yasunaga and Yasuyuki Ikegami

IOS8MX041-OT-R

Complete analytic solutions for convection-diffusion-reaction-source equations using an initial condition the Laplace space

Albert S. Kim

IOS8MX038-OT-R

Ice crystal growth in the freezing desalination process of binary water-NaCl system

Kunwei Wang, Jiatong Song, Yan Li, Ning Mei and Han Yuan

IOS8MX020-OT-R Analysis of a deep-sea pipeline for energy and desalination applications

Ashwani Vishwanath, Purnima Jalihal, and Abhijeet Sajjan

12:38 Keynote 3

Eng. Manuel A. J. Laboy Secretary of Economic Development and Commerce of Puerto Rico

“PROTECH: The first Deep Ocean Water Applications (DOWA) and Ocean Thermal Energy Conversion (OTEC) Technology Park in Las Americas”

Chair: Juan Barcenas

Session 4: Environmental, Social and Economy considerations Chair: Juan Barcenas

IOS8MX025-EnvC-R

Effect of Tropical Deepsea Water on the Growth of Dinoflagellate Scripsiella acuminata

Khayyirah N.Z, Nurul Saszuim M.R.K, Izyan Nurina M.H Mohd Shafiq R, Abu Bakar Jaafar, Suriyanti S.N.P.

IOS8MX028-SC-Env-R

The Role of Environmental and Socio-Economic Effects in Siting Small Scale OTEC in the United States

Andrea Copping, Lysel Garavelli , and Hayley Farr

IOS8MX029-SC-Env-S

A feasibility study of a model business for a social sustainable OTEC Power Plant in Oaxaca, Mexico

Pérez Casas Edgardo de Jesús and Díaz Díaz Carlos Rodolfo

IOS8MX036-E&C-R

Enhanced Economy of Ocean Thermal Energy Conversion

Thomas Noll, Mühlleit and Bernhard Puttke

13:48 14:03 IOS8MX008-EnvC-R Techno-Economic and Environment Assessment of Large-Scale OTEC Plants in the

Gulf of Mexico C. B. Panchal and Kruti Goyal

14:03 14:18

IOS8MX013-E&C-S

Ocean Thermal Energy Conversion Power Plant in Wholesale electricity Market Marisela Bernal-F

14:18 14:38

IOS8MX047-E&C-R

IEA/OES’s New White Paper on Ocean Thermal Energy Conversion (OTEC)

Martin G. Brown

14:38 14:48

Poster Session 2

Chair: Alonso Perez

14:48 13:53

IOS8MX016-OT-S

Viability study of a Solar Ocean Thermal Energy Conversion (SOTEC) in the Northwest coasts from Mexico

Jesús Florido Ortega

13:53 13:58

IOS8MX023-OT-S

Simulation of a OTEC System in Punta Diamante B.C.S. with TRNSYS Software Adrián Antonio Galindo De La Cruz, Nora Nayeli León Lizardi, Oscar Reséndiz

Pacheco, Madelein Galindo De La Cruz, Juan Antonio Martínez Chavelas, Ricardo Gallegos Ortega and Miguel Ángel Alatorre Mendieta

13:58 14:03

IOS8MX031-OT-S

Simplification of Heat Exchanger Selection for OTEC Using Carnot Cycle Based Maximum Power Output Assessment

Fontaine Kevin, Takeshi Yasunaga and Yasuyuki Ikegami

14:03 14:08

IOS8MX033-OT-S

3 kW Radial Turbine for OTEC Application: An Analysis on Volute Spiral Progression and Cut-Water effect to Flow Velocity at Stator Trailing Edge

Jasmi A.R., S. Mansor, N. Othman, M. Ab Wahid, N.A.R. Nik Mohd, W. Z. Wan Omar, S. Mat, I. Ishak, A. Abdul-Latif, N. Nasir, M. N. Dahalan, A. Ariffin

14:08 14:13

IOS8MX035-OT-S

Simulation and analysis of OTEC pre-expansion induced absorption cycles based on Aspen PLUS

Suyun Yi, Han Yuana Zhixiang Zhang and Xiaomeng Zhang

14:13 14:18

IOS8MX045-OT-S

Coastal Water Quality for Prospectively Constructed H-OTEC (Hybrid Ocean Thermal Energy Conversion) in Port Dickson, Malaysia

Nur Amiera Kamarudin, Azim Haziq, Md Yaekub Ali, Syaizwan Zahmir Zulkifli , Ferdaus Mohamat Yusuff, Natrah Fatin Mohd Ekhsan,, Mohd Zafri Hassan,

Ahmad Zaharin Aris, Fatimah Md Yusoff

14:18 14:23

IOS8MX041-OT-R

Cleaning Ball Dynamics in OTEC Heat Exchangers: Computational Fluid and Particle Dynamics (CFPD) Simulations

Albert S. Kim, Seung-Taek Lim, Ho-Saeng Lee and Hyeon-Ju Kim

14:23 14:28

Second Day Closing

8th International OTEC Symposium Time:GMT-5 Friday, January 29th

8:00 9:00 Registration

SESSION 5: OTEC Technology Chair: Víctor Romero

Time Title

IoT Structure for Bidirectional Monitoring and Maintenance of OTEC Plant Hiroshi Nakanishi

A Design of Radial Inflow Turbine Design for Ocean Thermal Conversion (OTEC) Technology

Nur Amyra Mohd Aseme, Ahmad Razin Jasmi, Norazila Othman, Mastura Ab Wahid, Shuhaimi Mansor , Ainullutfi Abdul Latif, Mohd Nazri Mohd Nasir, Iskandar Shah Ishak , Shabudin Mat, Wan Zaidi Wan Omar, Nik Ahmad Ridhwan Nik Mohd, ,

Mohd Nizam Dahalan, and Azrin Ariffin

Thermodynamics for the Standardization of Performance Evaluation on OTEC

Takeshi Yasunaga and Yasuyuki Ikegami

Based DMAC-R124 cogeneration of power and refrigeration of OTEC Absorption cycle

Zhixiang Zhang, Han Yuan, Nin Mei and Yan li

Ocean Thermal Energy Conversion Powered Desalination plant of 100 m3/day capacity at Kavaratti Island, India

G. Venkatesan, Trishanu Shit, Prasad V Dudhgaonkar, Biren Pattnaik and Purnima Jalihal

10:15 10:30

Transport Phenomena in OTEC Heat Exchangers: Multi-physics CFD Simulations

Albert S. Kim, Jiwon Yoon, Jung-Hyun Moon, Ho-Saeng Lee and and Hyeon-Ju Kim

11:20 Keynote 4 Dr. Hyeon Kim

“Current Status of OTEC Technology and Technical Readiness for Energy Transition”

Korea Research Institute of Ships and Ocean Engineering

SESSION 6: OTEC Technology Chair: Paola Garduño

Triple Phase Supercritical Carbon Dioxide OTEC Plant proposal Díaz Díaz Carlos Rodolfo, Pérez Casas Edgardo de Jesús ,García Pérez

Ernesto

Numerical Simulation of the Evaporator for the OTEC Plant Prototype for 1 kWe on the Mexican Caribbean

Bryant S. Delgado D., Erick Perez S., Emiliano Carrillo C. and Víctor M. Romero M.

Horizontal shell and tubes heat exchanger in OTEC Ammonia energy loop

B.Clauzade, Dr. D.Mas

Sensitivity analysis of the OTEC-CC-MX-1kWe prototype Yair Yosias Arriola Gil, Jessica Guadalupe Tobal Cupul, Estela Cerezo

Acevedo, Víctor Manuel Romero Medina and Héctor Fernando Gómez García

12:40 Break-time

12:40 13:20

Keynote 5 Dr. Rodolfo Silva Mexican Centre for Innovation in Ocean Energy (CEMIE-Océano)

“Ocean Energy in Mexico”

13:20 13:30 Closing Ceremony

Chair: Miguel A. Alatorre

SPEAKERS 8th International OTEC Symposium

Eng. Lamboy is Secretary of the Department of Economic Development and Commerce and Executive Director of the Industrial Development Company in Puerto Rico. He is currently the leader of the PROTECH project that investigates the implementation of OTEC technology in the port of Yabucoa, Puerto Rico, where it is expected to build and operate a 500 kW power generation plant, as well as the creation of a REGIONAL industrial park dedicated to the creation of an ecosystem that integrates applied research, innovation and economic development through the creation of industries derived from the use of deep sea waters.

Dr. Kim is the Principal Researcher, Offshore Plant, and Marine Energy Research Division, Korea Research Institute of Ships and Ocean Engineering and Project Manager of the Korean OTEC program. He received his Ph.D. at the Dept. of Ocean Engineering, Pukyong National University. His fields of specialization are OTEC system technology, Seawater Desalination, and Mineral Extraction system technology, Deep Ocean Water Application technology for Food, Energy and Water. He is Vice Chairman of the Korean Society for Power System Engineering and a Member of the board of directors of the Korean Society for Marine Environment and Energy and other associations.

SPEAKERS 8th International OTEC Symposium

Dr. Rodolfo Silva

Dr. Silva heads the Mexican Centre for Innovation in Ocean Energy (CEMIE-Océano, México). He is a professor in the Department of Hydraulics and the Environment of the Engineering Institute of the National Autonomous University of Mexico (UNAM). He is a specialist in coastal protection and maritime structures, coastal orphodynamics, operational oceanography, coastal zone management and renewable energy. Dr. Silva has published more than 400 scientific publications in national and international journals and has supervised more than 80 master's and doctorates in coastal engineering in Mexico, the Netherlands, and Spain.

PROCEEDINGS OF 8TH INTERNATIONAL OTEC SYMPOSIUM CANCUN, MEXICO | 27TH – 29TH JANUARY, 2021

Contenido

SESSION 1: RESEARCH RESOURCE ASSESSMENT, SEAWATER USES AND

ONGOING PROJECTS ........................................................................................... 4

Multiple deep sea water use in OTEC renewable power generation –socio-

economic variables and peculiarity ...................................................................... 5

OTEC-generated hydrogen for CO2 conversion into green hydrocarbons ........... 7

Recent Activity towards Combined Use of MW OTEC and Large-scale Seawater

Industries on Kumejima ........................................................................................ 8

Estimation of Ocean Thermal Energy Conversion (OTEC) Resources in Sabah,

Malaysia ............................................................................................................. 10

Investigating the performance of two ammonia-water compression/absorption

combined refrigeration system using ocean thermal energy .............................. 12

Spatial-temporal distribution of the OTEC Capacity Factor from SST data in

Mexican Coasts.................................................................................................. 14

SESSION 2: RESEARCH RESOURCE ASSESSMENT, SEAWATER USES AND

ONGOING PROJECTS ......................................................................................... 16

Comparative analysis of sea-surface temperature data for possible OTEC

implementation in the Mexican Pacific Ocean ................................................ 17

Ocean Thermal Energy Conversion – Flexible Enabling Technology for Variable

Renewable Energy Integration in the Caribbean. ........................................... 18

Simulation of a SWAC System at the Baja California Sur Peninsula .............. 20

Island State Case Study of Coproduction of Ammonia and Freshwater Using

Ocean Thermal Energy ................................................................................... 21

Cost Reduction Opportunities for Deep-Sea Cold-Water Air Conditioning

Systems (SWAC) ............................................................................................ 23

OTEC and cold deep Ocean Water can save the Climate .............................. 24

POSTER SESSION 1 ............................................................................................ 25

Characterization of seawater column between 0 to 1000 meter depth with

physical, chemical and biological parameters in Banderas Bay and Marías

Islands in the Mexican Pacific Ocean for OTEC prospection. ......................... 26

Determination of suitable sites for OTEC Implementation in Mexican Coasts

using a machine learning clustering algorithm ................................................ 27

Philosophy Gradients in the OTEC International Community. ........................ 29

Technical Feasibility of Central OTEC in Diamante, Baja California Sur, as a

Solution to the Great Energy Demand of the State. ........................................ 30

Occurrences and Distribution of Microplastic in the Surface Water of

Prospectively Constructed H-OTEC (Hybrid Ocean Thermal Energy

Conversion) in Port Dickson, Malaysia ........................................................... 31

SESSION 3: OTEC TECHNOLOGY ..................................................................... 33

Experimental study of Open Cycle OTEC power module on laboratory scale 34

Novel, enhanced thermal conductivity heat exchanger for OTEC ................... 38

Complete analytic solutions for convection-diffusion-reaction- source equations

using an initial condition the Laplace space .................................................... 40

Ice crystal growth in the freezing desalination process of binary water- NaCl

system ............................................................................................................ 41

Analysis of a deep sea pipeline for energy and desalination applications ...... 42

SESSION 4: ENVIRONMENTAL, SOCIAL AND ECONOMY .............................. 44

The Role of Environmental and Socio-Economic Effects in Siting Small Scale

OTEC in the United States .............................................................................. 45

Effect of Tropical Deepsea Water on the Growth of Dinoflagellate Scripsiella

acuminata ....................................................................................................... 47

A feasibility study of a model business for a social sustainable OTEC Power

Plant in Oaxaca, Mexico ................................................................................. 49

Enhanced economy of ocean thermal energy conversion .............................. 51

Techno-Economic and Environment Assessment of Large- Scale OTEC Plants

in the Gulf of Mexico ....................................................................................... 53

Ocean Thermal Energy Conversion Power Plant in Wholesale Electricity Market

........................................................................................................................ 55

IEA/OES’s New White Paper on Ocean Thermal Energy Conversion (OTEC)57

POSTER SESSION 2 ............................................................................................ 58

Viability study of a Solar Ocean Thermal Energy Conversion (SOTEC) in the

Northwest coasts from Mexico ........................................................................ 59

Simulation of a OTEC System in Punta Diamante B.C.S. with TRNSYS

Software. ......................................................................................................... 61

Simplification of Heat Exchanger Selection for OTEC Using Carnot Cycle Based

Maximum Power Output Assessment ............................................................. 62

3 Kw Radial Turbine for OTEC Application: An Analysis on Volute Spiral

Progression and Cut-Water effect to Flow Velocity at Stator Trailing Edge .... 63

Coastal Water Quality for Prospectively Constructed H-OTEC (Hybrid Ocean

Thermal Energy Conversion) in Port Dickson, Malaysia ................................. 65

Cleaning Ball Dynamics in OTEC Heat Exchangers: Computational Fluid and

Particle Dynamics (CFPD) Simulations........................................................... 67

IoT Structure for Bidirectional Monitoring and Maintenance of OTEC Plant ... 69

A Design of Radial Inflow Turbine Design for Ocean Thermal Conversion

(OTEC) Technology ........................................................................................ 70

Thermodynamics for the Standardization of Performance Evaluation on OTEC

........................................................................................................................ 72

Based DMAC-R124 cogeneration of power and refrigeration of OTEC

Absorption cycle ............................................................................................. 73

Ocean Thermal Energy Conversion Powered Desalination plant of 100 m3/day

capacity at Kavaratti Island, India ................................................................... 74

Transport Phenomena in OTEC Heat Exchangers: Multi-physics CFD

Simulations ..................................................................................................... 76

Triple Phase Supercritical Carbon Dioxide OTEC Plant proposal ................... 78

Horizontal shell and tubes heat exchanger in OTEC Ammonia energy loop .. 81

Sensitivity analysis of the OTEC-CC-MX-1kWe prototype .............................. 82

SESSION 1:

RESEARCH

RESOURCE

ASSESSMENT,

SEAWATER USES AND

ONGOING PROJECTS

IOS8MX039-SWU-R

Multiple deep sea water use in OTEC renewable power generation

–socio-economic variables and peculiarity

Masanori Kobayashi a*and Atsushi Watanabea

aOcean Policy Research Institute of the Sasakawa Peace Foundation (OPRI-SPF),

1-15-16, Toranomon, Minato-ku, Tokyo, Japan

*Corresponding Author: m-kobayashi@spf.or.jp

ABSTRACT

Multi-level use of deep sea water provides collateral socio-economic incentives to

operationalize renewable power generation through the ocean thermal energy

conversion (OTEC). In Kumejima, Okinawa, Japan, 13tons of deep sea water is

pumped per day for OTEC from its launch in 2013 to generate 100kw of power and

then thereafter distributed through multiple levels to apply deep sea water to heat

exchange on experimental vegetable farming, shrimp and sea grape aquaculture,

cosmetic production, and thalassotherapy. The secondary use of deep sea water

generates the economic value that worth JPY 2.48 billion or USD 22.5 million

annually. The economic returns from the entire OTEC operation including the use of

deep sea water is now much greater in the secondary use of deep sea water than

renewable power generation. However, the economic efficiency in the use of

secondary deep sea water largely depends on the local socio-economic conditions.

In Kumejima, shrimp aquaculture farming was initiated much earlier than the

introduction of OTEC and deep sea water. That provided a basis for the use of deep

sea water to increase the value addition to the farmed shrimps. The proximity to the

major market to Naha, capital city of the Okinawa Prefecture and the marketing

networks to the major cities also support the operation of shrimp aquaculture. Shrimp

aquaculture production with the use of deep sea water in Kumejia doesn’t however

show a linear growth. For Okinawa Prefecture as a whole, the shrimp production

doesn’t show a liner growth either. It was 608 tons in 2010 and declined to 397 in

2015, and surged to 549 tons in 2018, but not to the level of 2010. However, the

value of shrimp production per unit was improving steadily. It was JPY4 million per

ton in 2010 but started to improve to reach JPY5.3 million per ton in 2015. It stayed

above JPY5 million as it was JPY5.08 million 2016 and 5.10 million in 2017. The

strategies for increasing value addition to aquaculture with the use of deep sea water

are seemingly important to raise the economic impact of deep sea water use.

Nonetheless, the seafood market was devastated by the COVID-19 crisis in Japan

since March 2020. As restaurants and hotels were closed as preventive measures

against the COVID-19 infections, the demand for seafood particularly luxury seafood

items dropped and impaired the seafood industry. The market conditions are peculiar

to the location of the OTEC and deep sea water facilities. The degree of elasticity

and resilience to market conditions also vary depending on the types of products

and services that operate with the use of deep sea water. One risk hedge strategy

would be to diversity the use of deep sea water to be more resilient to the external

shocks and market disruptions such as those that appeared in the COVID-19. Such

consideration and strategies would be vital in planning the installation or expansion

of the OTEC

Keywords: OTEC, deep sea water, multi-level use, aquaculture, blue economy, blue

recovery stagnates around increased from.

IOS8MX034-OO-R

OTEC-generated hydrogen for CO2 conversion into green

hydrocarbons

A. Bakar Jaafar2, Mohd Khairi Abu Husain3 and Sathiabama T Thirugnana4

ABSTRACT

It has been well established that Malaysia has the potential of generating at least

26,000 MW of ocean thermal energy. Since most of the suitable sites are over 60 km

from the nearest coastlines, it would be not that economical to transmit the generated

power to the nearest State-wide Grids. However, the surplus power could be

converted into green hydrogen, and be taken up by the oil and gas industries, that

are operating in the deep waters off the States of Sabah and Sarawak, Malaysia, for

the conversion of the CO2 emitted from these activities into methanol or ammonia.

Such a mechanism would not only help to take up the abundant renewable energy

in the deep waters of Malaysia, but would also help reduce the carbon emissions

from the oil and gas activities. Furthermore, it would facilitate the oil and gas

industries to shift their current focus from incurring the high costs of their current

strategies in capturing and then storing the emitted CO2 back into the deep wells,

into generating revenues by producing green hydrocarbons.

IOS8MX006-OP-R

Recent Activity towards Combined Use of MW OTEC and Large-

scale Seawater Industries on Kumejima

Benjamin Martina*, Shin Okamurab and Naoki Otac

aGlobal Ocean reSource and Energy Association (GOSEA) Institute., Kumejima,

Okinawa, Japan

bXenesys Inc., Tokyo, Japan

cKumejima Town Government, Kumejima, Okinawa, Japan

*Corresponding Author: benjamin@xenesys.com

ABSTRACT

This presentation will introduce the background and status of activities towards

realization of the Kumejima Model, a concept for combining MW-scale OTEC and

seawater industries in Okinawa. Activities underway and next steps will also be

discussed.

OTEC development in Japan, which began in 1973, is ongoing at Okinawa’s 100kW-

class demonstration facility, which over the past 8 years, has contributed data and

momentum towards OTEC commercialization. Long-term use of OTEC equipment in

situ and the evidence, data, and knowhow garnered from it, establish the technical

reliability of components and OTEC as a power generation method.

Kumejima, an island 100km from the Okinawa mainland with a population of less

than 8000 people was selected as site for he Okinawa Deep Seawater Research

Center (ODRC) which was established in 2000 with surface (SSW) and deep

seawater (DSW) intake capacities of 13,000m3/day. Since 2010, Kumejima Town

has been working towards the realization of the Kumejima Model, which is a concept

combining use of MW-scale onshore OTEC and DSW use industries outlined in a

feasibility study of the same year.

The ODRC has enabled the creation and strengthening of seawater use industries,

which now have annual revenue of 2.5 billion JPY/year at nearly full use of summer

DSW capacity. Main industries include Kuruma Prawn hatchery and farms, sea

grape farm, cosmetics, oyster farm research, and bottled water. In addition, the

existing seawater resource enabled the establishment of the OTEC demonstration

facility as a step toward realization of the Kumejima Model. The limited seawater

capacity restricts further growth, however, research activities have shown potential

for the expansion of current industries and establishment of new activities.

As a spin-off project from the 100kW-class OTEC demonstration, Okinawa

Prefecture carried out “Advanced Multi-Purpose Post-OTEC Deep Seawater Use

Demonstration Project” from April 2016 to March 2019. This project utilized DSW

and SSW after use in OTEC for aquaculture (sea plant and oyster farming). In 2020,

Kumejima Town is continuing work through “OTEC Power Generation and Post-

OTEC Combined Seawater Use Demonstration Work.” We are carrying out hearings

to bolster the understanding of current and future industrial use of DSW including

market and economic situations and business cases of major industries.

The preliminary results support the case for seawater intake expansion to

sustainably support Kumejima’s shift towards clean energy while strengthening self-

sufficiency in energy, water, and food production. As a further step towards

realization, Kumejima Town plans to implement surveys towards MW-scale

seawater intake and related facilities in fiscal years 2021-2022.

Keywords: OTEC, Japan, Deep Seawater Use, Kumejima, Combined Use.

IOS8MX014-RRA-R

Estimation of Ocean Thermal Energy Conversion (OTEC)

Resources in Sabah, Malaysia

Sathiabama T. Thirugnanaa*, Abu Bakar Jaafara, Takeshi Yasunagab, Tsutomu Nakaokab,

Su-N.P. Suriyantic and Yasuyuki Ikegamib

aRazak Faculty of Technology and Informatics & UTM Ocean Thermal Energy

Centre, Universiti Teknologi Malaysia, 54100, Kuala Lumpur, Malaysia

bInstitute of Ocean Energy, Saga University, Imari City, Saga Prefecture, Japan

cDepartment of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia

*Corresponding Author: sathiabama@utm.my

ABSTRACT

Malaysian Government has set a target to achieve 20% penetration of Renewable

Energy (RE) in the energy mix spectrum by 2025. In order to get closer to the target,

Ocean Thermal Energy Conversion (OTEC) aligned with Solar PV, Biogas and

Biomass must be evaluated and comprehended. Hybrid OTEC systems consisting

of energy and water production are under research and validation in Science and

Technology Research Partnership for Sustainable Development (SATREPS)

Program. For the construction of a commercial OTEC plant, 1MW or 2.5MW, the

choice of a strategic location or potential site is vital. In this paper, oceanographic

data of seawater temperature, depth, salinity and dissolved oxygen analysed from

Japan Oceanographic Data Center (JODC) of Semporna, Tawau, Kudat, Pulau

Layang-Layang, Pulau Kalumpang of Sabah, Malaysia were reported. The RE

available from Exclusive Economic Zone (EEZ) in the coast of Sabah is estimated

based on the JODC data obtained. There was no remarkable difference of

temperatures between the five sites which read approximately 27 °C on the surface

temperature and 7 °C at depth below 500 m. The surface salinities below 100 m of

those sites were slightly lower than the deeper waters where the salinity increased

up to appx. 34.5 PSU. Dissolved oxygen represented by Kalumpang site has shown

slight increment to approximately 4.7 ml/l during depth intervals at below 50 m before

declined steadily to approximately 1.7 ml/l with depth. The T-S (Temperature -

Salinity) profiles of the Malaysian sites were in congruent with Palau, Kumejima and

Okinawa with exception to Fiji in which the salinity profile showed a distinct variation

at the relative depth (below 200 m). Estimates of RE using two different methods;

i.e. heat quantity of temperature difference and heat flux of solar energy; were used

to prove the prominence of OTEC in Malaysia. It was found that the renewable

energy to be generated by the OTEC system within the Malaysian EEZ should

amount to, similar to and 4 times, respectively of the current government RE targeted

Power Generation by 2025.

Keywords: Marine Profile; Power Generation; Ocean Thermal Resource;

Renewable Energy; Malaysia

IOS8MX012-SWU-R

Investigating the performance of two ammonia-water

compression/absorption combined refrigeration system using

ocean thermal energy

Zheng Hua, Dan Huab and Chengbin Zhanga*

aKey Laboratory of Energy Thermal Conversion and Control of Ministry of

Education, School of Energy and Environment, Southeast University, Nanjing,

Jiangsu 210096, PR China

bSchool of environmental science and engineering, Suzhou university of science

and technology, Suzhou, Jiangsu, PR China

*Corresponding Author: cbzhang@seu.edu.cn 230198429@seu.edu.cn; huadan@usts.edu.cn; cbzhang@seu.edu.cn

ABSTRACT

The implementation of the cooling capacity used for cold storage and freezing of

seafood in coastal and island areas, using traditional compression refrigeration,

consumes a lot of primary energy, which exacerbates energy crisis and many

environmental problems. How to reduce electricity consumption while meeting

cooling capacity needs, is the key issue to be considered in achieving sustainable

development. In this paper, the ammonia-water compression/absorption combined

refrigeration system using deep seawater after use in OTEC power generation since

it maintains low temperature (9-12 degrees Celsius) is proposed, enabling small

amounts of power consumption to generate the required cold storage capacity. Two

kinds of ammonia-water compression/absorption combined refrigeration system,

with compressor in high-pressure stage and low pressure stage respectively, are

investigated. And the mathematical model of the two aforementioned systems based

on conservation of mass, first law of thermodynamics and second law of

thermodynamics is established, in order to compared performance under different

design conditions, with the refrigeration temperature of 258.15K, cooling capacity of

5kW. Moreover, In order to compare the power consumption between the

compression/absorption combined refrigeration system and compression

refrigeration system, the heat powered coefficient of performance (HPCP) is used in

this study and the effect of changes in seawater temperature on the heat powered

coefficient of performance is performed.

The results indicate that the system with compressor in low-pressure stage is

superior to that in high pressure stage. For the proposed system, with compressor in

low-pressure stage, the exergy efficiency, which is 10.5% higher by adding solution

heat exchanger, is as high as 31.12% when the mid-pressure is 0.4510MPa. The

component with maximum exergy destruction rate is absorber whether the

compressor is in high-pressure stage or low-pressure stage. It should be noted that

the optimal working points, considering the exergy efficiency and heat powered

coefficient of performance respectively, are different. In addition, for the system with

compressor in low-pressure stage, the heat powered coefficient of performance is

higher. The coupling scheme of compressor and intermediate pressure should be

reasonably selected in the design to ensure that the minimum power consumption of

refrigeration system.

Keywords: ocean thermal energy, compression/absorption combined refrigeration,

PR equation, exergy, heat powered coefficient of performance,

IOS8MX004-RRA-S

Spatial-temporal distribution of the OTEC Capacity Factor from

SST data in Mexican Coasts

E. Paola Garduño-Ruiz 1*, Yandy Rodríguez-Cueto1, Alejandro García-Huante1, Juan

Francisco Bárcenas-Graniel2 and Rodolfo Silva-Casarín1

1Instituto de Ingeniería, Universidad Nacional Autónoma de México, Edificio 17,

Ciudad Universitaria, Mexico City 04510, Mexico,

2Universidad del Caribe,Lt. 1 Mz. 1 Esq. Fracc. Tabachines SM 78 CP 77528 Cancún, Quintana Roo, México

*paola.quimar@gmail.com

ABSTRACT

This work explores a proposal to estimate the Capacity Factor (GCF) of OTEC plant

from Sea Surface Temperature (SST) data and their spatial-temporal behavior in

Mexican coasts. We estimated the CF for an OTEC-CC-50MW, with ammonia as

working fluid into a polygon of 15 km from the coast to the Economic Exclusive Zone

(EEZ) of Mexico. The database used in this paper was the Satellite Oceanic

Monitoring System (SATMO, from its name in Spanish) with a comprehensive daily

SST data with a temporal resolution of 16 years (1 Jun 2002 - 24 Aug 2018) and

spatial resolution of 0.01 x 0.01 grades, which was useful to estimate: (a)

Temperature Differences (TD) between the sea surface and 1000m deep waters, (b)

Power production by Electric and Nihous´ method, (c) the system efficiency and (d)

CF. Sea Bottom Temperature at 1000 m (SBT1000m), were analyzed from World

Ocean Atlas (WOA, 2013) with a temporal resolution of 57 years (1955 – 2012). The

SBT-1000m were defined as 5 ºC with a standard deviation of 0.019 – 0.230 ºC. TD

analysis was the result of the subtraction of Daily SST and SBT- 1000m, their

variation range were 18.11 – 25.0 ºC, with the condition of DT ≥18 ºC. Estimations

were made with the following assumption, the heat supplied (Qs) by the seawater is

equal to heat rejected by the working fluid in the condenser. We calculated the system

efficiency of OTEC plant through the experimental (EE) and theoretical (ET) behavior.

EE data came from Lee et al., where a quadratic equation describes the behavior of

EE in function of TD. ET estimations came from Net Power and Qs. The range of

variations of system efficiency were EE 0–1.88%; ET 0-3.38%. The power production

was estimated using two equations: (1) Electric Power (Pe), which involves ET and

Qs, (2) Net Power (PN) by Nihous´ method. The range of variation for power

productions were (1) Pe:0–42.53 MW and (2) PN:0-76.40 MW. The Electrical

Production (EP) was calculated using Pe and a daily average of TD in each point in

the database. TD < 18 ºC was reclassified to zero production, dividing it by the

number of days in the year. According with the spatial-temporal distribution, the

optimal areas for OTEC deployment are the Mexican Pacific (MP) Ocean and

Caribbean Sea with CF around 100%, guaranteeing their operation during all days

of the year.

Keywords: OTEC, Capacity Factor, Mexican Coasts

SESSION 2: RESEARCH

RESOURCE

ASSESSMENT,

SEAWATER USES AND

ONGOING PROJECTS

IOS8MX001-RRA-R

Comparative analysis of sea-surface temperature data for

possible OTEC implementation in the Mexican Pacific Ocean

Alejandro García Huante*a, Yandy Rodríguez Cuetoa, Erika Paola Garduño Ruíza,

Ricardo Hernández Contrerasb, Miguel Ángel Alatorre Mendietaby Rodolfo Silva Casarínc

aPosgrado en Ingeniería Civil, Facultad de Ingeniería, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, 04510 Ciudad

de México, México.

bInstituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, 04510 Ciudad de México,

México.

cInstituto de Ingeniería, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, 04510 Ciudad de México, México.

*Corresponding Author: AGarciaHu@iingen.unam.mx

ABSTRACT

The OTEC cycle responds quickly to SST changes, so a variation in this parameter

can significantly modify the energy produced by an OTEC plant. The purpose of this

paper is to present a comparative analysis of three sea-surface temperature

databases (WOA, SATMO, and sensor in-situ measurements). Multiple correlations

and graphic comparisons allow correlations to be made between distribution

patterns of the Sea Surface Temperature. The results show that there is no

statistically significant difference between the three databases. For macroscales,

such as the entire Mexican Economic Exclusive Zone, it is recommendable to use

the WOA database, due to the smaller amount of data to be analysed. For

mesoscales and microscales, areas corresponding to Gulf of Mexico, Mexican

Caribbean Sea, Gulf of California, Gulf of Tehuantepec and other regions of Mexican

Pacific Ocean, it is recommendable to use SATMO and in-situ measurements due

to the necessity of higher spatial resolution. Certain oceanographic processes, such

as river discharge or upwelling, modifying the sea surface temperature only can be

seen using SATMO and ins-situ data, so it is recommendable to use those

databases for identifying those processes.

Keywords: OTEC cycle, WOA, SATMO, power net, thermal gradient, sea surface

temperature

IOS8MX003-RRA-R

Ocean Thermal Energy Conversion – Flexible Enabling

Technology for Variable Renewable Energy Integration in the

Caribbean.

R. J. Brecha1,2,3,4,*, Katherine Schoenenberger4, Masaō Ashtine5, Randy Koon Koon6

1Climate Analytics, Ritterstr. 3, 10969 Berlin, Germany

2Physics Dept., University of Dayton, Dayton, OH, USA 45469

3Renewable and Clean Energy Program, University of Dayton, Dayton, OH, USA

4Hanley Sustainability Institute, University of Dayton, Dayton, OH, USA 45469

5Department of Engineering, University of Oxford, United Kingdom. 6Department of Physics, University of the West Indies, Mona Campus, Jamaica, W.I.

*Corresponding Author: robert.brecha@climateanalytics.org

ABSTRACT

Most Caribbean island nations are heavily dependent on imported fossil fuels for

both power and transportation, leading to energy dependence that can be vulnerable

to external events beyond the control of the individual states, both in terms of

supplies and uncertain costs. Furthermore, this dependence on imported fuels has

negative impacts on net balance of payments for the countries. A paradox arises in

that Caribbean island nations are generously endowed with solar and wind energy

potentials not having strong seasonal variability, thus obviating the need for long-

term storage as is the case in higher-latitude countries. At the same time, small

island developing states (SIDS) are at enhanced risk from the impacts of climate

change, although their own emissions represent only a very tiny fraction of the

global total responsible for climate change. SIDS have been leaders in advocating

for the Paris Agreement target in its call for limiting global warming to “well below

2°C,” interpreted most clearly as maintaining at least a 50% likelihood of not

exceeding an increase of more than 1.5°C with respect to the pre-industrial global

average surface temperature. With the increasing recognition that domestic

renewable energy resources would be adequate to supply energy needs, Caribbean

islands have the potential to lead in demonstrating the ability to transition to 100%

sustainable, renewable energy systems, including in the implementation of

technologies such as OTEC that may not play a large role for energy systems

globally.

In this work we present several results linking Ocean Thermal Energy Conversion

(OTEC) and 100% renewable energy systems for island states. First, we report a

GIS mapping of the near- coastal bathymetry of all islands in the Caribbean to

determine the best sites for potential resources for land-based Ocean Thermal

Energy Conversion (OTEC). We couple these results with a screening of the most

advantageous countries for OTEC due to the lack of other dispatchable renewable

power options that will be necessary to complement wind and solar energy. As a

motivation for the use of OTEC we use hourly data to explicitly show the trade offs

between battery storage needs versus dispatchable renewable sources for energy

systems moving toward the phase-out of fossil fuels and dominated by variable solar

and wind power. In another step, we analyze tradeoffs and estimated total system

levelized costs for combinations of variable renewables, dispatchable renewable

power and storage to achieve 100% renewable electricity generation. Although

viewed as a stand-alone technology OTEC appears to be prohibitively expensive,

when it is considered as a technology that enables higher penetrations of cheaper

variable renewables, overall system levelized costs of electricity may well be lower

than those of a fossil-fuel-based system. Finally, this last point is emphasized to

demonstrate the further utility of open-cycle OTEC together with accompanying

desalination (and perhaps sea-water air conditioning) in enabling a high penetration

of renewable energy with lowered system costs.

Keywords: Ocean thermal energy conversion, OTEC, seawater air conditioning,

SWAC, desalination, variable renewable energy, wind power, solar PV, 100%

renewable energy, Caribbean.

IOS8MX024-OT-S

Simulation of a SWAC System at the Baja California Sur

Peninsula

Juan Antonio Martínez Chavelasa, Elizabeth Chávez Martíneza Oscar Reséndiz Pachecoa

and Miguel Ángel Alatorre Mendietab

aDepartment of Engineering, Autonomous University of Baja California Sur, Forjadores Blvd., La Paz, México

b Institute of Marine Sciences and limnology of the National Autonomous

University of México

*Corresponding Author: ja.martinez@uabcs.mx

ABSTRACT

The state of Baja California Sur (BCS) is located at the south region of the peninsula

of California, where the weather is dry and hot most part of the year. Because of

this, the electric demand on the concept of climatization is extremely high. Moreover,

the state of BCS is not connected to the National Electrical Network, which means

that said state relies completely on the electrical energy that it produces by itself.

Due to the high populational growth, the electrical energy produced is going to be

exceeded by the demand in a near future, that why we need to start thinking on

renewable alternatives.

Deep cold ocean and sea water is a renewable natural resource which can be used

to produce electrical energy, air conditioning, desalination, aquaculture and

agriculture. Thanks to its location, the state of BCS has a high potential to benefit

from seawater technologies, among them the sea water air conditioning (SWAC).

The purpose of this work is to demonstrate the viability of a SWAC system in the

state of BCS. To achieve this the system is going to be simulated with the help of

the software TRNSYS. The simulation provides information on the behavior of the

system with the given conditions and it also allow us to dimension the size of the

components in the SWAC system.

Keywords: SWAC, Simulation, TRNSYS, México

IOS8MX007-SWU-R

Island State Case Study of Coproduction of Ammonia and

Freshwater Using Ocean Thermal Energy

E3Tec Service, LLC, 2815 Forbs Avenue, Suite 107, Hoffman Estates, Illinois

60192 USA

Corresponding Author: cpanchal@e3-tec.com

ABSTRACT

The world’s oceans are the largest collectors and storage of solar energy and have

an enormous potential to supply growing worldwide energy demands, commodity

products like ammonia and freshwater. This case study focuses on the island market

for implementation of the Ocean Thermal Energy Conversion (OTEC) in the

foreseeable future of two decades. Small Island Developing States (SIDS) and other

island states exclusively rely on petroleum-liquid, specifically fuel oil and diesel-

based power generation and desalination of seawater. For example, power

generating capacities of Mauritius, Reunion, St Thomas and St Croix are 480 MW,

435 MW, 200 MW and 120 MW, respectively. Fossil energy represents 50% to 80%

of the total energy source, with remaining coming from hydro or bagasse or biomass.

The uncertainty of supply and price of refined petroleum-liquid fuel on a long-term

basis has adverse impact on the sustainability of the island states as pointed out at

the 2005 UN sponsored SIDS conference in Mauritius. Furthermore, the perceived

climate disruption is expected to have an undesirable impact on the supply of

freshwater for the island states that will require desalination of seawater using

renewable energy. The purpose of this case study is to demonstrate that the island

states can become the major producers of OTEC-based ammonia and freshwater

that would make them fossil-energy free society and export ammonia as a hydrogen

carrier. Ammonia as a hydrogen carrier for fuel-cell based automobiles will provide

fossil-free fuel for the island market as well as an export commodity to other

countries. Ammonia can be directly used as fuel for agriculture equipment displacing

diesel. Ammonia is being evaluated as marine fuel; therefore, the island states can

become refuelling stations for an expanding marine transport of goods. This island

state case study consists of: a) ammonia as marine fuel; b) ammonia as hydrogen

carrier for island transportation; c) ammonia as fuel for agriculture equipment; d)

production of freshwater that the Island States will require with the impairing impact

of climate change; and e) exporting ammonia for displacing ammonia produced by

gasification or coal and petroleum coke in other countries. This case study

demonstrates that with full implementation of the OTEC technology by 2040 for the

tropical islands, a finite impact on the global abatement of carbon dioxide is

expected.

Keywords: Island States, Ammonia, Fresh Water, Climate Change, Hydrogen,

Marine fuel

IOS8MX011-SWU-R

Cost Reduction Opportunities for Deep-Sea Cold-Water Air

Conditioning Systems (SWAC)

Caroline Le Floc’ha, Olivier Langearda and Bruno Garnierb*

aDepartment of Renewable Energies, DORIS Engineering, 58A rue du Dessous des Berges, Paris, France

bDe Profundis, 53 boulevard Victor Hugo, Clichy, France

*Corresponding Author: bruno@deprofundis.com

ABSTRACT

A SWAC (Sea Water Air Conditioning) system is an innovative and ecological air-

conditioning technology which uses the renewable source of deep sea cold oceanic

water. It is particularly fitted to islands in the tropical belt where air conditioning is

needed year-round and where a vast reservoir of cold oceanic water is available

close by. Deep cold sea water is pumped to the surface through an underwater pipe

system and then passes through a heat exchange system onshore to cool down the

air conditioning network. Once used, the pumped water is then released back into

the ocean at a dedicated depth. This paper looks at the technical solutions to

economically design, fabricate and install a deep water SWAC system. One of the key

parameters is to minimize the risks and uncertainties by selecting solutions pertinent

to the SWAC applications, such as low-cost materials and fast-track offshore

installation methods. An example of such a low-cost SWAC technology is proposed

in this paper, through the development of a deep water (1,000m water depth pipe

entry point) SWAC system for Kingston airport in Jamaica. Additional cost reduction

avenues such as the use of a flexible pipe, an auto-burial system, will be presented

in detail. Finally, the availability of nutrient-rich deep-sea water enables the parallel

development of agricultural projects, bringing additional value to the SWAC

systems.

Keywords: SWAC, cost reduction, installation, flexible pipe

IOS8MX010-OO-R

OTEC and cold deep Ocean Water can save the Climate

Peter Hovgaard, Fjord Forsk Sogn as, 6852 Sogndal, Norway. peterhov@hotmail.no *

and Lars Golmen

Runde Environmental Centre, Rundavegen 247, 6096 Runde, Norway, and Norwegian Institute of Water Research. Thormohlensgate 53 D.

lars.golmen@niva.no

ABSTRACT

All evidence is clear that the reductions in CO2 and other emissions will not be

enough to reach the Paris accord of maximum two degrees Celsius increase in

global atmospheric temperature. It is therefore necessary to find other ways of

saving the climate. We suggest that the use of OTEC to produce electric energy that

is transferred to a set of other vertical tubes to pump up cold deep-water rich in

nutrients, and distribute it evenly near the surface of selected ocean areas, can have

several beneficial effects: 1. Reduce the surface ocean temperature and thus

reduce the formation of tropical storms. 2. The addition of nutrients to the surface

layers will increase the primary productivity and generate a production of

zooplankton and fish that can be harvested. 3. Increased photosynthesis over large

areas will bind a lot of CO2. 4. Sequestration of CO2 will reverse both the increase

in atmospheric temperature and the acidification of the oceans. The selection criteria

of regions for implementing such a technology will be based on oceanographic

conditions, storm generating history, depth and topography. We suggest the

following: The Atlantic Ocean east of the Caribbean Sea and Florida, The Gulf of

Mexico, The Indian Ocean east of Mozambique, The Pacific Ocean east of Japan

and the Philippines. These areas are centers of tropical storm formation and are low

in primary productivity today.

Keywords: Climate, OTEC, cold deep-water, CO2, tropical storms, photosynthesis,

fisheries.

POSTER SESSION 1

IOS8MX005-EnvC-S

Characterization of seawater column between 0 to 1000 meter

depth with physical, chemical and biological parameters in

Banderas Bay and Marías Islands in the Mexican Pacific Ocean

for OTEC prospection.

Ricardo Efraín Hernández Contreras*a, Miguel Ángel Alatorre Mendietaa, Leonora

Fernanda Mondragón Sáncheza, Yandy Rodríguez Cuetob, Erika Paola Garduño Ruízb,

Alejandro García Huante and Rodolfo Silva Casarínc

aInstituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, 04510 Ciudad de México,

México.

bPosgrado en Ingeniería Civil, Facultad de Ingeniería, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, 04510 Ciudad

de México, México.

cInstituto de Ingeniería, Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, 04510 Ciudad de México, México.

ABSTRACT

The objective of this project is characterization of seawater columns between 0 to

1000 m depth. Seawater columns have a variation in ocean parameters in different

periods of time such as: monthly or annual throughout several years. Using

information from PO. DAAC and Marine Copernicus for data. The project is focused

on two of several optimal locations for OTEC in the Mexican West Coast along the

Pacific Ocean: Bahía de Banderas and Islas Marías. The seawater columns

characterization is making comparisons of: temperature, salinity, nitrates,

phosphates, oxygen, silicates, carbonates and chlorophyll. Knowing prevailing

conditions in seawater columns is in order to have a more realistic and clear vision

of the possible benefits and environmental alterations. If it is possible to someday

have a working OTEC plant in Mexico.

Keywords: seawater column, OTEC, Mexican West Coast, Pacific Ocean, Bahia

de Banderas, Islas Marías, ocean parameters, environmental alterations,

PO.DAAC, Marine Copernicus, temperature, salinity, nitrates, phosphates, oxygen,

silicates, carbonates, chlorophyll.

IOS8MX009-RRA-S

Determination of suitable sites for OTEC Implementation in

Mexican Coasts using a machine learning clustering algorithm

S.A. Reyes-Romeroa*, E. Mendozab and M. Roblesa

aInstitute for Renewable Energy, National Autonomus University of Mexico, Priv. Xochicalco S/N, Temixco Morelos 62580, Mexico

bInstitute for Engineering, National Autonomus University of Mexico, Circuito

Escolar S/N, Ciudad Universitaria, Alcaldía Coyoacán, Ciudad de México, Mexico

*Corresponding Author: rerosa@ier.unam.mx

ABSTRACT

Marine energy is a renewable source available from the ocean. It includes the ocean

and tidal currents, saline gradient and thermal gradient worldwide known as Ocean

Thermal Energy Conversion, i.e. OTEC. The energy density in the oceans is higher

compared to other renewable energy sources, due to the large amount of energy

that marine water can storage by area unit. Therefore, marine energy is a promising

renewable energy despite of still remaining at low Technology Level Readiness.

OTEC takes advantage of the temperature difference between the surface seawater

temperature and the deep seawater temperature to run, mainly, an Organic Rankine

Cycle (ORC). Research conducted concludes that a minimum difference

temperature (or thermal gradient temperature) of 20 °C is needed for a techno-

economic feasibility of the plant. So, in this work, the determination of the thermal

gradient power availability was made considering this minimum value. Hence, after

mapping the shallow and deep-sea water temperatures, the optimum sites for an

OTEC Plant deployment are those where a temperature difference of 20 °C or more

was found. Shallow and deep seawater temperatures for this study were obtained

from the available global computational simulations of HYCOM (Hybrid Coordinated

Ocean Model) for a time period of 5 years and with a longitude-latitude spatial

resolution of 1/12° for all the Mexican Littoral. The site selection was performed by

running machine learning's clustering algorithm known as “K-Means”. This algorithm

found the regions that have similar thermal gradients in order to determine the sites

with lower and higher potential for an OTEC plant deployment. K-Means algorithm

selected 2 potential sites with mean thermal differences greater than 27 °C. The two

places are one, close to Isla Cozumel, Quintana Roo and the other is near El

Palmarcito, Chiapas. An ORC simulation was run in the selected sites using diverse

organic working fluids to determine which place shows the best thermal and exergetic

efficiencies. This simulation gave 3% and 24% of thermal and exergetic efficiencies,

respectively. The efficiencies obtained are acceptable for an OTEC Plant

deployment as stated in previous literature.

Keywords: OTEC Mexico, K-Means algorithm, HYCOM, Thermal and exergetic

efficiencies, Marine available power

IOS8MX017-SC-S

Philosophy Gradients in the OTEC International Community.

A Preliminary Mapping

Armando Alonso Pérez Pérez

PhD Student of Sustainability Sciences, Universidad Nacional Autónoma de México, Av. Universidad 3000, Mexico City, Mexico

alonsopp@ciencias.unam.mx

ABSTRACT

Science and philosophy have a common point of departure: exploring connections

between the human being and nature. In a context of titanic technical endeavours –

as the energy conversion from the sea–, it seems remote that science is always a

philosophy. But whenever a question is posed next to theoretical assumptions,

methodologies, or interactions in the socio-political realm, the upwelling of reality,

knowledge and ethics appears. The intention of this preliminary work is to

characterize a philosophical landscape within the OTEC international community,

investigating through surveys and brief interviews perspectives ranging from the

current knowledge of the oceans to the challenge (according to the environmental

politics of the Sustainable Development) of developing interdiscipline in order to

accomplish social goals. Even though natural scientists and engineers are at the

core of this work, their collaborations with social scientists and scholars from

humanities will be taken in consideration in order to capture the intellectual network

gathered around the study and uses of the ocean thermal gradient. Following certain

guides concerning the relations between science and philosophy, politics and ethics

(Peirce, 1902; Habermas, 1968; Haas, 1977; Miller, 2015) a couple of models are

proposed in order to locate and characterize the ideas and influences of the

participants. As part an ongoing work of a doctoral research, it’s a methodological

attempt that aims to be a diagnosis fashioned for the 8th OTEC Symposium more

than an exhaustive analysis. The ultimate concern, deriving from this preliminary

mapping, is tracing possible pathways for achieving interdiscipline through the

active discussion among the OTEC international community, and to find out if aside

from the methodologies of social impact, parallel philosophical issues could

genuinely flourish.

Keywords: Philosophy of Science, OTEC International Community, Ethics,

Interdiscipline

IOS8MX022-RRA-S

Technical Feasibility of Central OTEC in Diamante, Baja California

Sur, as a Solution to the Great Energy Demand of the State.

Marisol García Espinozaa, César Ángeles Camachob, Oscar Reséndiz Pachecoa,

Madelein Galindo De la Cruza and Miguel Ángel Alatorre Mendietac

aDepartment of Engineering, Autonomous University of Baja California Sur, Forjadores Blvd., La Paz, México

b Institute of Engineering of the National Autonomous University of México

c Institute of Marine Sciences and limnology of the National Autonomous

University of México

*Corresponding Author: m.garciae@uabcs.mx

ABSTRACT

The Baja California Sur headland is, due to its geography, a state that has his own

power grid, which makes energy production costs one of the highest in the country,

but it´s also a coastal state that lies between the Pacific Ocean and the Sea of

Cortez which makes it a state with high potential in Ocean Energies. In this work we

talk about the feasibility of implementing an open- cycle Ocean Thermal Energy

Conversion (OTEC) with a capacity of 200kW in El Diamante, Baja California Sur to

mitigate power supply deficiencies and as part of a solution to drinking water

shortages in some areas. The choice of site was determined by the temperature

conditions of the region, which meets a temperature gradient of at least 20°C. The

surface and depth temperatures of the site were analyzed to determine the profile of

the variation of the surface temperature and the net power calculated the KW that

the power plant would have for a year. An open-cycle power station was envisaged,

which generates fresh water as waste that can be used for human use, another

reason why this area was chosen in particular, is due to the overcrowding of the

municipality to meet the demand for basic services. The results show that, despite

the need to carry out a cost study to determine the real viability, in this work we

focus only on the technical feasibility, which demonstrates that the installation of an

OTEC plant is feasible and necessary for the sustainable development of the state.

Keywords: OTEC, El Diamante, Baja California Sur.

IOS8MX032-EnvC-S

Occurrences and Distribution of Microplastic in the Surface Water

of Prospectively Constructed H-OTEC (Hybrid Ocean Thermal

Energy Conversion) in Port Dickson, Malaysia

Azim Haziq Zainuddina, Ahmad Zaharin Arisa,b*, Fatimah Md Yusoffa,c, Nur Amiera

Kamarudina, Md Yaekub Alia, Syaizwan Zahmir Zulkiflia,d*, Ferdaus Mohamat Yusuffa,b,

Natrah Fatin Mohd Ekhsana,c, Mohd Zafri Hassana,c

aInternational Institute of Aquaculture and Aquatic Sciences, Universiti Putra

Malaysia, Port Dickson 71050, Negeri Sembilan, Malaysia

bDepartment of Environment, Faculty of Forestry and Environment, Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia

cDepartment of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia

(UPM), 43400 Serdang, Selangor, Malaysia

dDepartment of Biology, Faculty of Science, Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia

*Corresponding Author: zaharin@upm.edu.my

ABSTRACT

Extensive global plastic production causes the ubiquity of microplastics (MPs)

pollution in the aquatic environment. However, the abundance and distribution of

MPs in the marine ecosystem is scarcely discussed and need further understanding.

The marine ecosystem receives the MPs input either from point-sources of the

nearby coastal activities and river flow input. The occurrences of MPs may disturb

various trophic levels of marine species through biomagnification and

bioaccumulation. The presence of MPs may also become the sources of plastic

additives released into the marine ecosystem and increase the potential

concentrations of other emergent contaminants such as Endocrine Disruptor

Compounds (EDCs). Thus, the present study analyses the abundance and

distribution of MPs pollution in the surface water of the marine ecosystem in Port

Dickson, Malaysia. The study employed a volume reduce technique with a stainless

metal sieve to quantify MPs within the size > 25 µm. A total of 776 particles of

microplastic were identified in the surface water with the abundance means of MPs

ranged from

2.10 particles/L to 6.80 particles/L. The most dominant shapes identified were fibers

(60%), followed by pellets (18%), fragments (16%), and spheres (5%). Physical

characterization of MPs was acquired from stereomicroscope and Fourier transform

infrared spectroscopy (FTIR). Coastal recreational activities, hotels, jetty, and the

residential area nearby the Port Dickson contributed toward MPs pollution.

Anthropogenic activities, including transportation, fishing activity, and washing

clothes were attributed to the prevalence of fibers in the surface water. The

magnitude of MPs pollutions in both coastal and estuarine areas is similar since

there are no significant variances in terms of MPs abundancy across the study area.

Hence, this study can be used as a baseline and comparative study in the urbanized

coastal area receiving direct impact from human activities. Furthermore, ecological

risk assessment of MPs in the tropical marine ecosystem can be calculated and

serves as a new indicator for the coastal ecosystem health status.

Keywords: Microplastic, surface water, marine ecosystem, anthropogenic

activities.

SESSION 3:

OTEC TECHNOLOGY

IOS8MX021-OT-R

Experimental study of Open Cycle OTEC power module on

laboratory scale

*Biren Pattnaik, Karthikeyan A, Anand Mani, Ashok Kumar, Sajeev KS, Narasimha Rao,

Prasad Dudhgaonkar and Purnima Jalihal

National Institute of Ocean Technology, Pallikaranai, Chennai, India

EXTENDED ABSTRACT

Ocean thermal energy conversion (OTEC) is a clean source of electricity generation

from ocean by utilizing ocean thermal gradient. Harnessing energy using this

method has many technical challenges and to overcome this National Institute of

Ocean Technology (NIOT) has setup India’s first of its kind laboratory to carry out

research and development activities on OTEC in its Chennai campus. This paper

focuses on evaluation of an indigenously developed open cycle OTEC (OC-OTEC)

power module that has successfully generated electricity using ultra low pressure

turbine working on water vapour. This turbine was indigenously developed and its

stator and rotor were fabricated using selective laser sintering technique of rapid

prototyping.The paper describes Open Cycle OTEC principle (OC-OTEC),

methodology and parametric study with change in warm water temperature and

testing. These studies are very useful for understanding process parameters for the

Open Cycle OTEC based desalination plant and also for setting up of large scale

OTEC and self sustained OTEC base desalination plant in India.

(a) Schematic diagram

(b) Power Module (c) Condenser

Fig. 1 Schematic diagram of OC-OTEC powered desalination plant

The Open Cycle OTEC system in the laboratory consists of flash chamber,

power module (turbine and generator), condenser, vacuum system, freshwater

tank, warm water pumps and cold water pumps as shown in Fig. 1. These

components are connected with steel and HDPE pipes. The details of this

laboratory scale Open Cycle OTEC plant components are given in the Table 1.

Table 1: OTEC Laboratory Components

OTEC-LTTD Laboratory Parameter

Flash chamber

Type Circular

Size Ø 1 m and x 2 m log

Flash chamber Operating Pressure 25-40 mbar

Temperature of Feed water temperature 27 - 29 ˚C

Mass low rate of Feed Sea water 30 m3/ hr

Condenser

Type Shell and Tube

Size Ø 0.8m x 6 m Long

Shell type Water vapour

Tube side Cold water

Condenser operating pressure 20-40 mbar

Mass low rate of Cold water 30 m3/ hr

Temperature of cold water temperature 8 - 10 ˚C

Vacuum system

Type Oil ring

Capacity 150m3/hour

Freshwater

Water conductivity 10 PPM

Type of flow Gravity

Power Module (Turbine and Generator)

Turbine

Type Axial flow

Tip diameter of turbine, Do 0.196 m

Mean diameter of turbine, Dm 0.165 m

Number of turbine rotor blade 30

Generator

Type Permanent magnet

synchronous

generator

Generator Capacity 2 kWe, 48 V

In this process, the warm surface sea water is partially vaporized in flash chamber

by maintaining a suitable low pressure of 30-35 mbar using a vacuum system. The

generated vapour passes through the duct and drives the turbine, which is coupled

with an electric generator to generate the electricity. The vapour then follows its path

towards condenser where it gets condensed using cold water to generate fresh

water.

The paper presents a study on OC-OTEC system to see the effect of varying

warm water temperature on system performance as shown in Fig. 2.

(a) (b)

(c) (d)

Fig. 2 Parameter study by varying warm water temperature in OC-OTEC Experiment.

Results and conclusion

This is a first laboratory setup of its kind in India where open cycle OTEC plant

generated electricity successfully. In this paper, the experiments were

performed keeping the temperature difference (∆T) of 18.4 ˚C, 19.4 ˚C and 20.2

˚C respectively. The respective mass flow rate at various ∆T is 0.0275 kg/s,

0.0285 kg/s and 0.0295 kg/s. The setup utilized an axial turbine of tip diameter

196 mm and generated peak electrical power of around 580 W at speed 16000

rpm with ∆T of 20.2 ˚C and vapour mass flow rate of 0.0295 kg/s. The pressure

drop across turbine found to be 16 mbar. This paves the way for further

optimization and scaling up.

Keywords: Ocean Energy, OTEC, Open cycle OTEC (OC-OTEC),

Desalination.

IOS8MX018-OT-R

Novel, enhanced thermal conductivity heat exchanger for OTEC

Meng Soon Chionga*, Feng Xian Tana, Srithar Rajooa, Sathiabama T.

Thirugnanab, Takeshi Yasunagacand Yasuyuki Ikegamic

aUTM LoCARtic, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor, Malaysia

bUTM Ocean Thermal Energy Centre, Universiti Teknologi Malaysia, 54100 Kuala

Lumpur, Malaysia

cInstitute of Ocean Energy, Saga University, 1 Honjo-machi, Saga 840-8502, Japan

*Corresponding Author (will be the speaker): chiongms@utm.my

ABSTRACT

In 2019, a 5-year joint collaboration project between the Malaysia and Japan

government in setting up a 1 kW Hybrid Ocean Thermal Energy Conversion (H-

OTEC) pilot plant in Malaysia has been initiated under the Science and Technology

Research Partnership for Sustainable Development (SATREPS) program. An

OTEC is a renewable and carbon free energy plant works by utilising the

temperature difference between the surface and deep ocean water, and the

electricity is generated by deploying an (organic) Rankine Cycle system. Being close

to the equator, Malaysia has the ideal geographical criteria for OTEC plant to

operate all year long. A Hybrid-OTEC is a direct evolution of conventional OTEC by

integrating a flash chamber at the OTEC evaporator, thereby enables seawater

distillation for drinking water production and more importantly, eliminates the

biofouling issue commonly found in conventional OTEC plant heat exchangers,

namely evaporator. Since OTEC plant operates by harvesting the seawater

temperature, the performance of evaporator is vital to the overall plant generation

efficiency. Therefore, one of the project deliverable is a new concept evaporator

design that could deliver better performance than existing commercial design. There

are three measures of a heat exchanger performance in practise – the effectiveness,

defining how well the heat is being transferred; the pressure drop performance on

the extent of flow pressure has lost in the process of heat transfer; and the footprint,

which is the size or space required by the heat exchanger. Realistically these

performances are rarely being met simultaneously. Plate heat exchanger (PHE)

conventionally used in OTEC plant is known to have very compact footprint and high

effectiveness, but the downside being suffer from higher pressure drop. This would

alter the saturation point of OTEC working fluid and consequently limits the

amount for extractable work for the given seawater temperature difference. Thus,

the new evaporator design in this project is aimed to improve the pressure drop

performance while maintaining the small footprint and high effectiveness. This

presentation will describe the approach in achieving the objective of this project, the

design concept of the new evaporator and also the facility to be established as part

of the SATREPS program’s vision in capacity development. The evaporator design

starts with the thermodynamic analysis of the target pilot plant, from which the

operating condition may be downscaled for the design and development of a lab-

scaled heat exchanger test facility. The conceptual design of the new evaporator

could then be derived from the boundary condition, and the performance is analysed

using three dimensional computational fluid dynamics (3D-CFD) simulation. The

combination of lab-scaled test facility and computational model enables more

affordable development cycle of the new evaporator. Once validated with

experimental results, the 3D- CFD model is targeted for generating parametric data

for optimisation study.

Keywords: OTEC, evaporator, heat exchanger.

IOS8MX042-OT-R

Complete analytic solutions for convection-diffusion-reaction-

source equations using an initial condition the Laplace space

Albert S. Kim*

a Department of Civil and Environmental Engineering, University of Hawai`i at Manoa, 2540 Doles Street Holmes 383, Honolulu, Hawaii, 96822, USA

*Corresponding Author : albetsk@hawaii.edu

ABSTRACT

Transient mass-transfer phenomena occurring in natural and engineered systems

consist of convection, diffusion, and reaction processes. The coupled phenomena

can be described by using the unsteady convection diffusion-reaction (CDR)

equation, which is classified in mathematics as a linear, parabolic partial-differential

equation. The availability of analytic solutions is limited to simple cases, e.g.,

unsteady diffusion and steady convective diffusion. The CDR equation has been

considered analytically intractable, depending on the initial and boundary conditions.

If spatial adsorption and desorption of matter are super-positioned in the CDR

equation as sink and source functions, respectively, then the governing equation

becomes an unsteady convection-diffusion-reaction-source (CDRS) equation, of

which general solutions are unknown. In this study, a general 1D analytic solution

of the CDRS equation is obtained by using a one-sided Laplace transform, by

assuming constant diffusivity, velocity, and reactivity. This paper also provides a

general formalism to derive 1D analytic solutions for Dirichlet/Dirichlet and

Dirichlet/Neumann boundary conditions. Derivations of the

analytic solutions are found to be straightforward if a combination of the source

function and the initial concentration provide a non-zero singularity pole of inverse

Laplace transform.

Keywords: Analytic solution, transport equation, diffusion, convection

IOS8MX042-OT-R

Ice crystal growth in the freezing desalination process of binary

water- NaCl system

Kunwei Wanga, Jiatong Songa, Yan Lia, Ning Meiaand Han Yuanb*

aDepartment of Engineering, Ocean University of China,

238 Songling Road, Qingdao 266100, China

*Corresponding Author: hanyuan@ouc.edu.cn

ABSTRACT

In this study, ice crystal growth in the freezing desalination process of binary water-

NaCl system is investigated. The phase field method is used to conduct simulation

and predict dendrite growth behaviour during the crystallization of sea ice. Including

the single nucleus crystallization, multi nucleus competition crystallization as well as

the directional competitive crystallization progress. An experimental setup focusing

on the directional crystallization of binary water-NaCl solutions on the horizontal wall

is established to verify the e theoretical model. The morphological simulation results,

the orthogonal analysis and the experimental results on the directional competitive

crystallization show that the crystal with single nucleus obtains obvious six-fold

symmetry, while in the competitive crystallization of multiple crystal nuclei, spindle

growth is inhibited. Brine channels and salt cells are formed in the directional

crystallization, seawater consists of higher Mg2+ and SO 2-get more difficult in

freezing desalination. The degree of subcooling significantly affects the salt cell

concentration at the roots, the solid phase ratio, and the height of the planar crystal,

while the heat flux significantly affects dendrite growth rate. The experimental

average tip growth rate is 9.15 × 10-5 m/s, and the experimental average tip radius

5.16 × 10-6 m. Peclet number of both simulation and experiment have the same order of magnitudes, with 0.1–0.2 and 0.3–0.6, respectively, which suggests the three field coupling model established is reasonable for desalination simulation.

Keywords: Freezing desalination, Phase field method Simulation, Directional crystallization, Experimental study.

IOS8MX020-OT-R

Analysis of a deep sea pipeline for energy and desalination

applications

Ashwani Vishwanatha*, Purnima Jalihalb, and Abhijeet Sajjanc

abcNational Institute of Ocean Technology, Chennai, India

*Corresponding Author: ashwani.niot@gov.in

ABSTRACT

One of the most challenging and complex components of a thermal gradient based

Ocean Thermal Energy Conversion (OTEC) plant is the long pipeline to draw cold

water from the deep sea. An ocean thermal gradient based energy and desalination

plant is being proposed which will use an over 3.5 km long High Density

Polyethylene (HDPE) pipe of large diameter for conveying deep sea cold water from

a depth of more than 1000 m to an onshore plant. The pipeline in in-place condition

takes an inverted catenary shape with one end connected to bottom clump weight in

deep sea and other end to sump near onshore plant. Since the pipeline material is

HDPE making it positively buoyant, it has to be weighted down at several segments

by adding clump weights. These features make the installation challenging as the

operation has to take care of safe stresses, bending radii, ease of lowering, vessel

responses, etc., during different sequences of operation. The analyses consist of

towing and upending simulations of the pipeline to achieve in-place condition at the

site. Various dynamic simulations were carried out to arrive at key parameters such

as vessel motion, no. of buoyancy modules, and sequence of their removal from

pipeline during installation, and stresses encountered. The article compares the

results under the situations arising when both ends of pipeline are closed and with

and without buoyancy modules connected at sagging lengths of pipeline during

towing operations. Results of lowering the pipeline to achieve the in-place

configuration are also discussed. Since the depth of pipeline end to draw cold water

is of high importance, care is taken to land this end at desired depth before fixing

its onshore end. Buoyancy modules attached at various sections of pipeline are

removed in sequence during lowering of pipeline end to desired depth with the help

of a winch available on the vessel. The dead clump attached to the pipeline end

ensures the end depth and thus the intake of cold water temperature. The pipeline

in-place configuration consists of an over 3.5 km of HDPE pipeline weighted down

using suitable weights at few intervals and other additional segments such as steel

pipe, holdfasts, dead clump weight etc. Extensive analyses for in-place design

conditions were performed towards optimization and finalization of the pipeline

configuration. The article discusses the complex non-linear analyses for the

configuration and its installation.

Keywords: OTEC, cold water pipeline, installation

SESSION 4: ENVIRONMENTAL,

SOCIAL AND

ECONOMY

IOS8MX028-SC-Env-R

The Role of Environmental and Socio-Economic Effects in Siting

Small Scale OTEC in the United States

Andrea Coppinga*, Lysel Garavellia, and Hayley Farra

aCoastal Sciences Division, Pacific Northwest National Laboratory, 1100 Dexter Ave N., Suite 500, Seattle, USA

*Corresponding Author: andrea.copping@pnnl.gov

ABSTRACT

The harvesting of OTEC resources has not been explored extensively in the United

States; government support has been limited to developing technologies and

assessing energy resources for large scale temperature differentials in open ocean

water that can provide baseload electricity-scale power. However, within U.S.

nearshore waters there are many potential sites at which smaller scale OTEC

development (~1-10MW) may be possible. These sites can be found around

Caribbean and Pacific Islands and off the coast of Florida. At this smaller scale,

OTEC can provide power to small island communities, deliver desalinated seawater

to remote locations, power aquaculture operations, and extend the life and range of

ocean observing platforms.

We are examining existing OTEC technologies for their capacity to provide small

scale OTEC at suitable island and remote locations in US waters. The potential

environmental and socio- economic effects associated with each technology, in the

specific locations will be identified. The federal, state, and local laws and regulations

pertinent to small scale OTEC will be explored to identify regulatory permitting

processes and social licensing requirements in US waters. We will use these

technology-specific criteria and associated effects to create a framework for siting,

identifying key gaps in data, and planning for research and development that will

support development. Elements of an outreach program will be designed to acquaint

regulators and stakeholders with information on the benefits and potential effects of

small scale OTEC, with the purpose of facilitating streamlined permitting and

acceptance processes, as well as to communicate potential OTEC benefits and

uses to residents of island and remote communities. This presentation will share the

process under development for identifying promising locations in US waters for

small OTEC, examining the environmental and socio-economic effects specific to

those locations, and creating a framework for further investigation.

Keywords: Environmental effects, social and economic effects, small scale OTEC

siting

IOS8MX028-SC-Env-R

Effect of Tropical Deepsea Water on the Growth of Dinoflagellate

Scripsiella acuminata

Khayyirah N.Z1, Nurul Saszuim M.R.K2, Izyan Nurina M.H2, Mohd Shafiq R3, Abu Bakar

Jaafar3 , Suriyanti S.N.P.1

1 Department of Earth Sciences and Environmental, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor, Malaysia.

2 Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia.

3 Razak Faculty of Technology and Informatics & UTM Ocean Thermal Energy Centre, Universiti Teknologi Malaysia, 54100, Kuala Lumpur, Malaysia

*Corresponding Author: suriyanti@ukm.edu.my

ABSTRACT

The potential of deep sea energy resources could be materialized through OTEC

technology. Differential temperatures for the working turbine is achieved through

deep sea water pumping and discharging at the thermocline layer. Naturally, the

nutrient-rich deep sea water would be dispersed along with the processes. As it may

be beneficial for higher productivity derived from the artificial upwelling and nutrients

discharged from the OTEC plant, the proliferation effects on the bloom-forming

dinoflagellate species is of great concern. This study reports the effect of deep sea

water on the growth of dinoflagellate Scripsiella acuminata in comparison to surface

seawater. The cultures were grown in enriched K media under constant conditions

of 25 ºC and 12:12 photoperiod cycles. Cells were inoculated for counting under a

light microscope in every alternate day. The initial cell count for normal seawater is

11.3×104cells L-1 while for deep seawater is 2.3×104cells L-1. The average density

of cells in normal seawater culture is higher compared to deep sea water which is

14.5×104 cells L-1 and 3.2×104 cells L-1 respectively. It was found that the cell

numbers were affected by the concentration of phosphate, silica, nitrate and

ammonia. The concentration of PO43-(0.041 to 0.043μM), Si(OH)4(0.035μM), NO3-

(0.014 to 0.016μM), and NH3 (0.019 to 0.020μM) in deep sea water. The cell

density in both media bases decreased overtime in conjunction with normal life span

of dinoflagellate in culture. This preliminary ex-situ study depicts potential shifts in

the natural phytoplankton abundance by a large deep seawater input. Further study

of impact of various physico-chemical components on the growth physiology of

indigenous phytoplankton community has been conducted tentatively.

Keywords: algal blooms, ex-situ, nutrients, physiology

IOS8MX029-SC-Env-S

A feasibility study of a model business for a social sustainable

OTEC Power Plant in Oaxaca, Mexico

Pérez Casas Edgardo de Jesúsa*, Díaz Díaz Carlos Rodolfob

aArea de Potencia, Cinvestav Guadalajara Av. Del Bosque 1145, Zapopan,

Jalisco, México

bDesarrollo e Investigación, DTMI Antiguo Camino a Ixcotel 114, Oaxaca, México

*Corresponding Author: edgardo.otec@icloud.com

ABSTRACT

The present work introduces a model business for implementing a conceptual OTEC

Plant in the coast of Oaxaca, México, using a Social and Solidarity Economy

approach, considering methodologies for community integration in the process and

as an active part of it. It is known the Pacific coast, especially the region of Oaxaca

Mexico, has a big potential for OTEC Power Plants, but conventional approaches

esteemed that these plants should sale not only the electricity, but also sub-products

as extended markets in order to make them reliable at long term periods. In this

paper, it is presented a full model business, which not only consider the electricity

and sub- products sale but also the community integration through local

cooperatives as an essential aspect of the project. Cooperatives are proposed as

the core of the political and organizational method to ensure the success of the

operation of the formal power plant and its sub-industries implementation aiming to

the social acceptation. It is recognized that community acceptance are the key in the

following business plan to have higher chances of success at long term. The model

contemplates as well, the private initiative, academia and all levels of government

involved, from the municipality, state and federal secretaries and representatives,

to agrarian authorities. The studies analysed or developed, includes historical,

anthropological, legal and geopolitical perspectives, as well as how the technology

transfer can successfully be accomplished in communities with not significant

technological development. Also, this work presents results from projects already

accomplished, including first cooperatives created, agreements with academic and

communities in the region and founding for first stages for technology readiness and

socioeconomic studies.

Keywords: OTEC, Social and Solidarity Economy, Community-based business

model, OTEC

IOS8MX036-E&C-R

Enhanced economy of ocean thermal energy conversion

Thomas Noll, Mühlleite 2, 85110 Kipfenberg, Germany, tnoll1954@gmail.com

Bernhard Puttke, Schießstattweg 10, 82481 Mittenwald, Germany, bputtke@directbox.com

ABSTRACT

Oceans have the largest accessible energy storage capabilities of all near-surface

phenomena on earth, but it is enclosed as thermal energy and not easy to exploit

and to supply to energy hungry conurbations worldwide. In the past some success

has been demonstrated by the Ocean Thermal Energy Conversion process, the

OTEC Technique. As this is still an underestimated technique, actually lacking by a

low efficiency of about 3% and very moderate profitability, the purpose of the

development was twofold. First, to increase the efficiency of the OTEC-underlying

technical processes, and second, to slim the investment cost and to streamline the

logistic on connected transport and supply procedures.

In order to reach the first point, the underlying heat pipe process has been enhanced

by increasing the pressure spread thus optimizing the turbine efficiency. Basis is a

patent pending procedure, named eOTEC, which uses a different driving thermo-

dynamic behaviour, and simultaneously changes the most cost-relevant design

parameters compared to state-of-the-art OTEC-plants, with long water pipes for

connecting the heat exchangers located landside with the warm and cold water

reservoirs of the ocean. Different to the existing OTEC pilot plants, it allows more

site- flexibility, less restriction in temperature spread, and also the integration of

secondary thermal sources to overcome the disadvantages of two-phase impact on

high efficacy turbines.

In order to reach the second goal, the streamlining of supply and transport procedures, the research was focused on replacement of submarine cables for electricity supply to far-away community grids - with estimated price increase from 7 $Cts/kWh for 10km distance to 22 $Cts/kWh for 400 km (refer to the HGF-project) - by power-to-liquid or power-to-gas

technologies, if a more sophisticated logistic procedure will be installed. This

procedure is tightly connected to our eOTEC process. Based on the different

thermo-dynamic behaviour and the power-to-x conversion, a new supply and

delivery shipping procedure is figured out. This procedure enables a double usage

of transportation activities, avoiding cost increasing no-load transports, by

performing productive transport actions on both ways going back and forth from

destination port to plant site.

The findings of the research, based on the patent pending eOTEC approach, can be

summarized by the following achievements: (1) Full utilization of site specific given

temperature spread, (2) cost-minimized hardware design, (3) replacement of toxic

ammonia by harmless natural refrigerants, (4) optimized embedding of especially

adopted state-of-the-art power-to-x conversion processes with efficiency increase

of H2 electrolysis from today 70% to about 95% and last but not least (5) generation

of additional economic sources on inevitable necessary transport activities. As a

result, the overall economic outcome increases significantly.

Keywords: OTEC, thermo dynamic process, efficieny, thermal energy, transport,

temperature spread, power to-x, electricity production cost.

IOS8MX008-EnvC-R

Techno-Economic and Environment Assessment of Large- Scale

OTEC Plants in the Gulf of Mexico

E3Tec Service, LLC,

2815 Forbs Avenue, Suite 107 Hoffman Estates, Illinois 60192 USA

Corresponding Author: cpanchal@e3-tec.com

ABSTRACT

The world’s oceans are the largest collectors and storage of solar energy. Large scale

deployment of OTEC plants can have positive impacts on ocean environment beside

producing green power, freshwater and commodity products. This is specifically true

for the Gulf of Mexico, which has been one of the favourable sites for OTEC plants.

The Gulf of Mexico is a major producer of oil and natural gas and it can be major

producer of green power when oil sources start depleting in coming decades. At

current production rate of about 1.6 million barrels per day, the oil reserve will start

depleting by 2040 that will cause shutting down offshore oil production. OTEC can

be the next major source of energy from the Gulf of Mexico. The present assessment

study focuses on the following key elements of large-scale deployment of OTEC

plants in the Gulf of Mexico:

a) production of ammonia as hydrogen carrier; b) freshwater production for the

water-stressed Caribbean Island and Gulf States; c) conversion of captured carbon

dioxide from the Gulf States to specialty and commodity chemicals, such as

methanol, dimethyl ester and alkyl carbonates; and d) recovery and conversion of

carbon dioxide from seawater. The critical aspect of large- scale OTEC plants in the

Gulf of Mexico is to extract the energy from the surface seawater and discharge

mixed seawater at an optimal depth. The extraction of thermal energy from the

surface water and upwelling of deep-ocean cold water would reduce systematic rise

of the surface water temperature of the Gulf of Mexico. This is a visionary and

ambitious goal. However, in the recent years, surface temperature of the Gulf of

Mexico has increased by 1-2°C, which has believed to cause severe storms with

unpredictable intensity. Large-scale OTEC plants would have a positive impact on

the moderation of the Gulf of Mexico seawater temperature, beside direct

impact on the abatement of green-house gas emissions. Based on the previous

DOE studies, an analysis was performed for production of 3,000 tonnes per day of

ammonia along with desalination of seawater for assessment of techno-economic

merits of large-scale OTEC plants in the Gulf of Mexico. In a similar study, techno-

economic analysis of conversion of captured and transported carbon dioxide from

the Gulf States to methanol and other relevant specialty chemical was performed.

The analysis revealed that conversion of out-of-service oil platforms into OTEC

platforms would significantly reduce the total-installed-cost (TIC) by taking the credit

of dismantling and disposal of oil platforms. The Technology Readiness Level (TRL)

is at such a stage that first of the large scale OTEC plant can be deployed in

foreseeable future with low risks.

Keywords: Climate Disruption, Gulf of Mexico, Ocean Temperature, Commodity

Products, Oil Platforms

IOS8MX013-E&C-S

Ocean Thermal Energy Conversion Power Plant in Wholesale

Electricity Market

Marisela Bernal Francisco

Master of Energy Engineering National Autonomous University of Mexico Coyoacán, Mexico City, Mexico befmarisela@gmail.com

ABSTRACT

Derived from the Mexican Energy Reform in 2013, electrical and gas & oil sector

changed. Electrical sector allows private entities to operate as generators, suppliers

and trading since January 2016 and it has encouraged the use of renewable

energies, among which are the OTEC plants. Specific “clean energy goals” and

mechanisms to achieve them have also been established. The different generators

together with CFE (Federal Electricity Commission) (as a State-owned enterprise)

form the SEN (National Electric System). Generators have a direct influence

on the selection of the sale prices established within the SEN. Knowing the minimum

and maximum sales prices can help to establish an income range, which serve to

complement economic analysis to determine the profitability of a project.

SEN operates through the MEM (Wholesale Electricity Market), which is run by

CENACE (National Energy Control Center). The SEN is made up of 3 power system

zones and 1 small system called “Mulegé”, isolated from each other. CENACE is

responsible for assigning the dispatching instructions to power plants from the

cheapest to the most expensive. The latest technology to be assigned to meet

demand is the one that dictates the sale price, which is known as PML (Locational

Marginal Price). SEN has different technologies like Internal Combustion, Turbo

gas, Carboelectric, Conventional Thermoelectric, Nuclear Power, Combined

Cycles, Cogeneration, Geothermal, Hydro, Wind, Photovoltaic; this means the

Levelized Cost of Energy could vary a lot during the year.

The BCS (Baja California Sur

Interconnected System) has several

hours in which the prices are fixed by

expensive technologies, as Turbo gas,

this translates into PML’s as high as

291.73 [USD/MWh] (06/10/2020 Hour

22). The highest prices for energy and

capacity within the SEN have appeared

in BCS, the same potential zone as the

Cerralvo island and Los Cabos, which

offers a thermal gradient suitable for the installation of an OTEC plant. For example,

if we were to install a 10 [MW] OTEC plant with a load factor of 85% in the BCS

System and we know the energy prices (PML 132.05 [USD / MWh] average), we

can estimate the revenues for: energy, capacity, certificates of clean energy and

expenses for regulated tariffs in 2020, a profit in the market of $ 12,628,848.54 [USD

/ MWh-year] could be obtained.

In addition to oceanographic studies that guarantee the functionality of OTEC

technology, the monitoring and analysis of the wholesale electricity market (along

with the variables that influence it) is vital to select the best place to install an OTEC

plant within the Mexico’s current panorama.

Keywords: Mexican Electric Market, Local Marginal Price, Mexican National

Electric System

Figure 1 Averaged monthly PML [MXN/MWh] (Source: Trade On Energy)

IOS8MX047-E&C-R

IEA/OES’s New White Paper on Ocean Thermal Energy

Conversion (OTEC)

Martin G. Brown

Ocean Energy Systems Limited, Aberdeen, Scotland, U.K.

*Corresponding Author: martinbrown@oceanenergysystems.co.uk

ABSTRACT

This presentation introduces the key themes from OES/IEA’s new White Paper on

OTEC, which has had input from specialists around the world including India,

France, South Korea, Japan, China and the UK. The White Paper has been

developed to introduce to a wider audience the potential of OTEC and its significant

environmental benefits as the world transitions away from hydrocarbon

dependency. The document provides an accurate up to date explanation and

reference on OTEC for government agencies, project developers, engineers,

investment bankers, journalists, media organizations, the general public, etc. The

paper covers:

• the potential size of the ocean thermal energy resource,

• power generation options such as open and closed cycle

• associated by-products such as air conditioning and aquaculture,

• land based and floating OTEC systems

• past projects including successes and failures

• technology maturity, including the vital sea-water systems

• the status of relevant engineering design standards.

In the past “Road Blocks” to widespread OTEC deployments have been experienced and ways to overcome these obstacles are reviewed, including a road map of potential ways forward.

Keywords: OTEC White Paper, IEA, Technology Maturity.

POSTER SESSION 2

IOS8MX016-OT-S

Viability study of a Solar Ocean Thermal Energy Conversion

(SOTEC) in the Northwest coasts from Mexico

Jesús Forido Ortegaa

a Engineering Institute, Mexican Center for innovation in Ocean Energy, National Autonomous University of Mexico (UNAM) Ciudad Universitaria, Circuito Interior

S/N, Mexico City, Mexico

*Corresponding Author): florj@ier.unam.mx, florj@ier.unam.mx

ABSTRACT

Climate change around the world has affected each country due to supplying actual

lifestyle. In energy aspects the renewables energies remain as an option. Some

tropical countries with coastal zones, like Mexico, have natural thermal gradients

nearshore, however some of these coastal zones present an intermittent thermal

gradient during the year like in the Northeast of Mexico but also have solar potential

that can be used. In this work a simulation was made in three different Northeast

Mexican coasts in other to evaluate the viability of pre-heating surface ocean water

with two commercial solar plastic collectors existing in Mexico to reach the thermal

gradient of 20°C or more needed in OTEC systems during a time period of 1859

days from 2013 to 2018. The simulation program was made for different amounts of

collector numbers from five to a maximum of forty collectors interconnected in

series. For each group of collectors simulated in each coast a probability function

was associated which represents the probability of supplying the 20°C delta or more

during a certain period of consecutive hours. The results showed 10 solar collectors

of each type studied were enough to reach the delta needed but during a few hours

with the lower probability associated. Also, it was found that 30 or 35 were the

maximum number of plastic collectors that could take advantage of solar energy

available in each coast tested. Considering this amount of solar collectors when

using the first plastic solar collector model the range of preheating reached was from

20 °C to 45°C with an operative range from 6 to 9 continuous hours during 85% of

the total solar time simulated, on the other hand the second model available had a

preheating delta from 20°C to 25°C with an operative range from 3 to 8 continuous

hours during 80% of the solar time simulated. These results demonstrate an

opportunity of supplying de delta needed in coastal zones with unstable thermal

gradients during the day. However, more work needs to be done for night periods.

Keywords: SOTEC, plastic solar collector, NorthManuscript format, Northeast

mexican coasts.

IOS8MX023-OT-S

Simulation of a OTEC System in Punta Diamante B.C.S. with

TRNSYS Software.

Adrián Antonio Galindo De la Cruza, Nora Nayeli León Lizardia, Oscar Reséndiz

Pachecoa, Madelein Galindo De la Cruza and Miguel Ángel Alatorre Mendietab

aDepartment of Engineering, Autonomous University of Baja California Sur,

Forjadores Blvd., La Paz, México

b Institute of Marine Sciences and limnology of the National Autonomous University of México

*Corresponding Author: aa.galindo@uabcs.mx

ABSTRACT

In the last years, Los Cabos has had population growth highest of the state of Baja

California Sur, with a growth rate of 4.1%, this because of it´s a touristic zone with

many source of employment, that´s why every year come people from different

states of Mexico, in search of job opportunities for a better life quality, however, the

excessive growth and the high touristic demand in Los Cabos has caused

overpopulation and consequently a shortage of resources, mainly electrical shortage

and shortage of drinking water in some areas. The electrical system of Baja

California Sur, is not connected to the country´s power grid, so it depends on its own

generated energy, Los Cabos is a region at the southern tip of the Baja California

Sur bordering the Pacific Ocean, that give us a location and appropriate temperature

conditions to implemented an Ocean Thermal Energy Conversion (OTEC) System.

This work consists of proposing a design of the open-cycle OTEC System, onshore

type to generate 100 kW of electric power to deliver energy to approximately 250

household and drinking water, considering the own characteristics of Los Cabos in

Punta Diamante zone to validate with Trnsys Software, wish is suitable for simulating

efficiencies of hydraulic pumps, heat exchangers and power generation; and were

we introduce the data of the average surface thermal gradient and average thermal

gradient at 1000 meters of depth, both in summer and winter time.

Keywords: OTEC, Punta Diamante, Simulation, Trnsys.

IOS8MX031-OT-S

Simplification of Heat Exchanger Selection for OTEC Using

Carnot Cycle Based Maximum Power Output Assessment

Fontaine Kevina*, Takeshi Yasunagaband Yasuyuki Ikegamib

aGraduate School of Science and Engineering, Saga University 1 Honjo-Machi, Saga, Japan

bInstitute of Ocean Energy, Saga University, 1 Honjo-Machi, Saga, Japan

*Corresponding Author: fontaine.kevin.d@gmail.com

ABSTRACT

Ocean thermal Energy Conversion (OTEC) uses allows power generation using the

natural thermal gradient in the sea. Due to its huge potential and its ability to steadily

produce energy throughout the year, studies to increase its viability and make it

competitive compared to conventional power plants have been, and are still

conducted. Studies focuses on improving cycle performances or central elements

of OTEC, such as heat exchangers. The selection of a heat exchanger can be

challenging as they their main characteristics – heat transfer coefficient and

pressure drop – are separately evaluated in the literature. Based on finite-

time thermodynamics, this study proposes a method to compare the performance

of heat exchangers by computing the maximum net power output of the power plant

accounting for both the pressure drop and heat transfer coefficient of the heat

exchangers. The method was successfully applied to 3 different heat exchangers.

A maximum power output increase of up to 158% has been calculated when

comparing the heat exchangers. A difference as low as 3.7% in the maximum net

power output for a difference of 22% in the Reynolds numbers was found for two

different heat exchangers as well, leading to a higher required pumping power. The

seawater temperature was found to have no impact on the choice of the heat

exchanger although it decreases the net power output by up to 10% with every

temperature difference of 1°C.

Keywords: OTEC; plate heat exchangers; optimization; maximum power output;

finite-time thermodynamics

IOS8MX033-OT-S

3 Kw Radial Turbine for OTEC Application: An Analysis on Volute

Spiral Progression and Cut-Water effect to Flow Velocity at Stator

Trailing Edge

Jasmi A.R.,1 S. Mansor,1 N. Othman,1* M. Ab Wahid,1 N.A.R. Nik Mohd,1 W. Z. Wan

Omar,1 S. Mat,1 I. Ishak,1 A. Abdul-Latif,1 N. Nasir,1,2 M. N. Dahalan,1,2, A. Ariffin,1,2

1Aeronautics Laboratory, School of Mechanical Engineering, Faculty of

Engineering, Universiti Teknologi Malaysia

2Institute of Future Energy, UTM-OTEC, Universiti Teknologi Malaysia, Johor Bahru, Johor, Malaysia.

ABSTRACT

Ocean Thermal Energy Conversion (OTEC) is one of the potential renewable

energy resources which can be used to generate electricity in Malaysia. It is the

process where the working fluid of the system is drive by the temperature gradient

that exist between the sea water surface and the deep-water temperature at certain

dept. However, due to its low thermal efficiency to produce torque or shaft power,

selection of a particular type of turbine play a very important role to increase the

whole system efficiency. Ocean Thermal Energy Centre (OTEC) in Universiti

Teknologi Malaysia (UTM) has led the research and developments on advanced

ocean thermal energy conversion technology for low carbon society and

sustainability energy system for first experiment OTEC plant in Malaysia. In order to

accommodate OTEC low thermodynamic efficiency, A radial turbine for OTEC

application is proposed with a targeted output power approximate is 3kW using a

working fluid of ammonia and Rankine cycle are analysed. Mean initial inlet and

mean outlet temperatures of designed turbine are 23.33°C and 13°C, respectively.

Aeronautics team in UTM has come out with analysis and optimization design to

achieve optimum efficiency required. In this work, one-dimensional design followed

by detailed three-dimensional designed is developed by the thermodynamics input.

The design of stator, rotor and volute are developed with specific dimension. This

paper discusses the effect of the volute design parameter to study the effect to the

tangential velocity and performance efficient of the radial turbine. The analysis will

be focus on the spiral progression as it led the fluid flow through the turbine inlet to

produced flow impact to rotate the turbine. From the parameter effect of volute

design, the practical radial turbine can be produced in the future that will establish

the knowledge of the conceptual automated design and development of OTEC

turbine design from small to the big scale power generated OTEC plant in Malaysia.

Keywords: Power generated; Radial Turbine; Ocean Thermal Energy Conversion.

IOS8MX045-OT-S

Coastal Water Quality for Prospectively Constructed H-OTEC

(Hybrid Ocean Thermal Energy Conversion) in Port Dickson,

Malaysia

Nur Amiera Kamarudina*, Azim Haziqa, Md Yaekub Alia, Syaizwan Zahmir Zulkiflia,b,

Ferdaus Mohamat Yusuffa,c, Natrah Fatin Mohd Ekhsana,d, Mohd Zafri Hassand, Ahmad

Zaharin Arisa,c, Fatimah Md Yusoffa,d

aInternational Institute of Aquaculture and Aquatic Sciences (I-AQUAS), Universiti

Putra Malaysia, Port Dickson 71050, Negeri Sembilan, Malaysia

b Department of Biology, Faculty of Science, Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia

c Department of Environment, Faculty of Forestry and Environment, Universiti

Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia

d Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia (UPM), Serdang, Selangor, 43400, Malaysia

*Corresponding Author: nuramiera2510@gmail.com

ABSTRACT

Ramification of ocean-thermal power plant future discharges necessitates the

determination of baseline water quality supply from circumambient coast. A survey

was conducted to assess coastal water quality parameters and quality index in the

surface intertidal waters of Port Dickson where a hybrid ocean thermal energy

conversion (H-OTEC) power plant will be built in the near future. Two field-works

were held with an interval period of seven months between them (March and

September 2020). The various water quality parameters incorporate temperature,

pH, salinity, conductivity, and total dissolved solids(TDS) were measured to evaluate

the biochemical characteristics of water. These in situ water quality parameters were

determined at four sampling stations in the vicinity of Port Dickson shore, where

water samples were also collected from the respective stations. The collected

water samples were transported back to Universiti Putra Malaysia for nitrate (NO3-

N), total ammonia nitrogen (TAN), soluble reactive phosphorus (SRP), dissolved

oxygen (DO), fecal coliform (Escherichia coli), and total suspended solids (TSS)

analyses. Concentrations of all parameters were significantly different (p< 0.05)

between the two sampling occasions. The highest concentration of NO3-N was

2.3±0.67 mg/L (mean ± standard deviation), TAN was 0.316±0.24 mg/L, SRP was

0.165±0.04 mg/L, DO was 7.79±0.79 mg/L, E. coli 1002.5MPN/100ml, and TSS was

475.92±30.01 mg/L. Calculation of Malaysian Marine Water Quality Index (MMWQI)

revealed that all 4 sampling stations can be classified as Moderate Class with

reading in the range of 62–77.

Keywords: Water quality, nutrients, Escherichia coli, coastal waters, H-OTEC

IOS8MX041-OT-R

Cleaning Ball Dynamics in OTEC Heat Exchangers:

Computational Fluid and Particle Dynamics (CFPD) Simulations

Albert S. Kim*a, Seung-Taek Lim, Ho-Saeng Leeb and Hyeon-Ju Kimb

a Department of Civil and Environmental Engineering, University of Hawai`i at

Manoa, 2540 Doles Street Holmes 383, Honolulu, Hawaii, 96822, USA

bSeawater Utilization Plant Research Center (SUPRC), Korea Research Institute of Ships & Ocean Engineering, 124-32, Simcheungsu-gil, Jukwang-myeon,

Goseong-gun, Gangwon-do 219-822, Republic of Korea

ABSTRACT

Long-term use of a plate heat exchanger is desired but often hindered by the

accumulation of deposit layers on the exchanger's internal surfaces. As the fluid

passing through the heat exchanger slits are either cold deepsea water or warm

surface seawater, the interior surfaces' contacts with the natural organic and

inorganic materials are inevitable. The formation of these layers, called the fouling

layer, significantly decreases the heat exchanging performance, i.e., heat transfer

coefficients or thermal conductivities. The whole plate-packing systems need to be

disassembled for cleaning and re-assembled for regular operations. This on-site

cleaning takes time and workforce, and the operation should be stopped for a while.

In this light, small ceramic balls are introduced to the heat exchanger interior, and

their collisions to the internal wall are induced. By doing so, the inner wall surfaces

are cleaned, and the heat transfer coefficients are recovered to their original range.

The number of particles, particle sizes, and flow speed is an important parameter to

reduce the fouling layers without disassembling optimally. The current study

developed a cleaning ball dynamics method to predict performance and efficiency.

Keywords: Particle dynamics, Dissipative hydrodynamics, Stokesian dynamics, Fluid-Particle interactions.

SESSION 5:

OTEC TECHNOLOGY

IOS8MX040-OT-R

IoT Structure for Bidirectional Monitoring and Maintenance of

OTEC Plant

*Hiroshi Nakanishi

Institute of Ocean Energy, Saga University, Honzyou-Cho, Saga-Shi, Japan

*h.nakanishi@utm.my

ABSTRACT

IoT is well known as a monitoring system between remotely operating machines.

IoT system consists of sensors, machines, IoT gateways, Cloud storage system, AI

software and dashboard. Currently, machines monitoring by using IoT is limited to

monitor only the machine operation status. No remote control is permitted due

mainly to poor functional capability of IoT gateways. To realize correct maintenance,

it is very important to issue operational commands remotely from dashboards to

machines.

To realize precise diagnosis of machines, the author has researched the IoT system

which enables bidirectional communication between machines and remote

dashboards. A buffer system is proposed which is installed between IoT gateways

and machines. The buffer system decodes and interprets issued control commands

to machines and converts them to the machine specific operation codes.

To realize commonly useable buffer system, grouping of machines are now being

done such as production robots, 3D printers, processing machines and

commercially used machines. Command conversion rues are differently assigned

for each group.

Through use of the proposed buffer system, it is expected to realize useful

monitoring and maintenance for the on-shore and off-shore OTEC pants.

Keywords: IoT, bidirectional monitoring, control, OTEC

IOS8MX002-OT-R

A Design of Radial Inflow Turbine Design for Ocean Thermal

Conversion (OTEC) Technology

Nur Amyra Mohd Aseme a, Ahmad Razin Jasmia, Norazila Othman a*, Mastura Ab Wahid a,

Shuhaimi Mansora, Ainullutfi Abdul Latif a, Mohd Nazri Mohd Nasir a, Iskandar Shah

Ishak a, ShabudinMata, Wan Zaidi Wan Omara, Nik Ahmad Ridhwan Nik Mohd a, Mohd

Nizam Dahalana, and Azrin Arif inb

aDepartment of Aeronautics, Automotive, Ocean Engineering, Universiti Teknologi

Malaysia,, Johor Bahru, Johor , Malaysia

bInstitute of Ocean Thermal Energy Centre (OTEC), Universiti Teknologi Malaysia, Johor Bahru, Johor , Malaysia

*Corresponding Author : norazila@mail.fkm.utm.my

ABSTRACT

With the increasing demand on energy supply and fast economy growth has

reinforce the worldwide energy consumption. Due to these problems, researchers

have come out with promising energy technologies using renewable energy and one

of it is ocean thermal energy conversions(OTEC). Ocean thermal energy conversion

(OTEC) is a source of renewable energy that employs temperature difference

existing between water surface and some depth inside ocean. However, power plant

which uses specific power generation of OTEC system has not develop in Malaysia

especially turbine itself. Thus, this research paper focuses on the design of radial in

flow turbine that operates with minimum 3kW power output. With the help of theory

turbo- machinery and analytical method, the one-dimensional automated design

calculation of radial inflow turbine is developed by specific software. A working fluid

chosen for this turbine is refrigerant R717. The turbine is designed for inlet and exit

temperatures approximate of 23°C and 13°C respectively. Speed of the radial

turbine is chosen as 30000rpm. The design results are constructed in 3D geometry

by Computer Aided Design (CAD) software. Two small scales model radial turbine

were designed with variation of mass flow rate which are approximate 0.12kg/s and

0.15kg/s, respectively. The result of the geometry with mass flow rate 0.12kg/s

showed the rotor radius is 47mmandpoweroutput is 5.5kW, however for 0.15kg/s

mass flow rate the rotor radius and power output were higher by 49 mm and 7.32

kW. Further investigations were performed to bring out the effect of the different

input parameter on the turbine performance. It is shown that, the mass flow rate is

very important to improve the turbine efficiency. However, the rotational speed also

influences toward the size of the turbine, turbine torque and specific speed insert

the value size, turbine torque and specific speed and number of rotor blades.

Besides, the inlet temperature has the great impact on the power output turbine. The

performance prediction method is based on the preliminary design and can be

applied for future development an OTEC plant in Malaysia.

Figure 1 and Figure 2 show the dimension of turbine design for model 1 and model 2

radial turbine. Based on the calculation, the different is about the rotor design sizing

is small. The diameter for model 1is47mm however for model 2 is 49mm. The small

different of sizing happen for two models show the small contribution effect from

mass flow rate value. From 0.12kg/s to 0.15kg/s mass flowrate gives small changing

of rotor diameter sizing but the power output is exponentially increase. Therefore,

using refrigerantR717, only small amount of mass flow rate can produce the high

power output with the only small size of turbine needs in this project. The safety

procedure during installation of the refrigerant R717 in storage tank and how to

handle is on of the issue that need to be take into consideration in this project.

Keywords: Low-Grade Heat Energy, Organic Rankine Cycle, Radial inflow turbine,

Refrigerant, Turbo-machinery

Figure 1: Model 1 design

Figure 2: Model 2 design

IOS8MX015-OT-R

Thermodynamics for the Standardization of Performance

Evaluation on OTEC

Takeshi Yasunagaa* and Yasuyuki Ikegamia

aInstitute of Ocean Energy, Saga University, 1-honjo-machi, Saga, Japan

*Corresponding Author: yasunaga@ioes.saga-u.ac.jp

ABSTRACT

OTEC uses very simple process to convert the thermal energy stored mainly tropical

ocean into the electricity. The basics have been deeply discussed in the

thermodynamics for long time. However, in designs, operations and the evaluation,

we need to consider unique characteristics of OTEC to achieve the best

performance or lower electricity cost in the project. In the presentation, the

difference between conventional power plants and

OTEC in the thermodynamics will be explained and some evaluation methods will be discussed for the standardization of the performance evaluation method on OTEC.

Keywords: OTEC, thermodynamics, maximum power, exergy, finite-time

thermodynamics

IOS8MX037-OT-R

Based DMAC-R124 cogeneration of power and refrigeration of

OTEC Absorption cycle

Zhixiang Zhanga, Han Yuana, Nin Meia*and Yan li*

a College of Engineering, Ocean University China, 238 Songling Road, Laoshan

District, Qingdao 266100, China.

*Nin Mei: Nmei@OUC.edu.CN

ABSTRACT

The OTEC absorption combined cycle for cogeneration of power and refrigeration

through extraction and ejection is proposed, which can generate a cold source to

Fishery free, drive of ocean thermal energy based DMAC-R124 working fluid without

the compressor and have a good efficiency. The results of thermal analysis show

that the cycle dynamic coefficient is 0.99%, the cooling coefficient is 26.82%, and

the comprehensive efficiency can reach 68.31%. Furthermore, the work scope and

variable operating performance of this cycle are also studied from six dimensions:

reflux ratio, concentration, heat source temperature, cold source temperature,

refrigeration temperature, and ejection ratio.

Keywords: OTEC, Ejection, Cogeneration of power and refrigeration

IOS8MX026-OT-R

Ocean Thermal Energy Conversion Powered Desalination plant of

100 m3/day capacity at Kavaratti Island, India

G. Venkatesan*, Trishanu Shit, Prasad V Dudhgaonkar, Biren Pattnaik and Purnima

Jalihal

Energy & Fresh Water Group, National Institute of Ocean Technology – Ministry of Earth Sciences, Velachery – Tambaram Main Road, Pallikaranai, Chennai, Tamil

Nadu, India

* Email – gvenkat@niot.res.in

ABSTRACT

National Institute of Ocean Technology (NIOT) is an autonomous body working

under the Ministry of Earth Sciences, Government of India. As part of its research

activities, NIOT has established Low Temperature Thermal Desalination (LTTD)

plant at Kavaratti in May 2005, Agatti and Minicoy in 2011.These plants have been

generating fresh water continuously and have been extremely helpful to the people.

The plant runs on the principle of evaporating surface seawater (at about 28oC) in a

flash chamber maintained under low pressure (at about 27 mbar) and consequently

liquefying the resulting vapor in a condenser using deep sea cold water. A long pipe

is deployed in the ocean to draw the cold water (at about 12oC) from a distance

of about 600 m from a depth of about 350 m. The process is simple in operation with

low running and maintenance costs. The plant has been generating water

continuously and has been extremely helpful to the people of Kavaratti. However,

these plants use diesel generators for powering the plants.

Now NIOT proposes to establish an Ocean Thermal Energy Conversion (OTEC)

powered desalination plant of 100 m3/day capacity at Kavaratti Island in UT

Lakshadweep, India. This will generate power and fresh water by utilizing naturally

occurring ocean temperature gradient. The OTEC cycle to be used for the plant is

an open cycle one as the condensed water does not returned to the evaporator and

the overview of the process design is shown in the Figure.

Overview of process design using deep sea cold water pipe of OD 1000 mm

The plant consists of flash chamber, turbine-generator, condenser, direct contact

condenser and vacuum pump. The system is maintained at lower pressures such

that the pressure inside the flash chamber always remains below the vapour

pressure of supplied warm water (at about 28oC) by using a vacuum pump. This

results into the flash evaporation of a part of the supplied warm water. The generated

vapor drives a turbine and generates electricity, before being condensed back to

water in a surface condenser using deep sea cold water (at about 7oC) drawn

from the 1000 m water depth through a 3.5 km long HDPE pipe. The effect of

different deep sea cold water pipe diameter on seawater flow rates, vacuum load,

power generation and fresh water yield is carried out. The results of this theoretical

study show that deep sea cold water HDPE pipe with at least 1 m outer diameter is

necessary for the generation of 1 lakh liters per day fresh water without drawing any

external power requirement for the plant. However, the next step is to improve the

efficiency of the power module and pumps and the layout configuration that could

reduce the pumping head thereby reducing cold water pipe diameter. This can move

towards commercial viability. Thus the proposed plant serves additional purposes

such as powering the LTTD plant using clean energy and first demonstration of an

OTEC powered desalination system leading to scaling up in future.

Keywords: desalination, OTEC, cold water pipe diameter

IOS8MX043-OT-R

Transport Phenomena in OTEC Heat Exchangers: Multi-physics

CFD Simulations

Albert S. Kim*a, Hyeon-Ju Kimb, and Ho-Saeng Leeb and Jung-Hyun Moonb

a Department of Civil and Environmental Engineering, University of Hawai`i at

Manoa, 2540 Doles Street Holmes 383, Honolulu, Hawaii, 96822, USA

bSeawater Utilization Plant Research Center (SUPRC), Korea Research Institute of Ships & Ocean Engineering, 124-32, Simcheungsu-gil, Jukwang-myeon,

Goseong-gun, Gangwon-do 219-822, Republic of Korea

ABSTRACT

Heat exchanger is one of the essential components in OTEC technology, as it

determines the operation efficiency based on the evaporation and condensation of

working fluids. During the regular operation including the continuous phase changes

from liquid to gas and gas to liquid phases, it is important to identify the location of

the phase-change frontend. If it is too close to the inlet of the heat exchanger, the

rest of spaces are not fully utilized, but, the phase change occurs near the exit of the

heat exchanger, then the risk of liquid going out of the heat exchanger may happen.

Therefore, not only designing heat exchanger geometry and materials, but also

controlling fluid to locate the phase front at an optimal position is a crucial estimation

to maximize the heat exchanging performance. This work fundamentally address

the dynamic phase change phenomena studied using CFD simulations

Keywords: Plate Heat Exchanger, Heat Transfer, Mass Transfer, Cleaning Ball,

Phase Changes

SESSION 6:

OTEC TECHNOLOGY

IOS8MX030-OT-R

Triple Phase Supercritical Carbon Dioxide OTEC Plant proposal

Díaz Díaz Carlos Rodolfo a*, Pérez Casas Edgardo de Jesús b, García Pérez Ernesto a

aDesarrollo e Investigación, DTMI Antiguo Camino a Ixcotel 114, Oaxaca, México

bArea de Potencia, Cinvestav Guadalajara Av. Del Bosque 1145, Zapopan,

Jalisco, México

*Corresponding Author: carroddiaz@gmail.com

ABSTRACT

The current work presents a design for an OTEC plant, using supercritical carbon

dioxide within a novel triple phase cycle and sun irradiance with warm ocean water

as source of heat. Nowadays, is important to not avoid the importance of CO2 as

part of the greenhouse gases which provokes the global warming and weather

alteration in the planet. Nevertheless, in this work the CO2 can be identified as

working fluid for additional or solely power generation, and in hybrid designs. In all

the world is currently running in rushing times designs of novel power plants with

CO2 as working fluid, in other thermodynamical cycles, as Brayton, Rankine or

Organic Rankine Cycle, and even in novel cycles as the Allam. The evidence of all

this work is the factibility to increase the efficiency drastically in comparison to other

fluid of work, but also is the factibility to adapt to different kind of heat source and

applications. This work explains the factibility of CO2 as working fluid and all

developments in the world, and describes thermodynamical study, the energy

balance and how sCO2 can be used in a closed cycle system to produce energy

from sun and ocean water as low thermal gradient sources of heat with efficiency up

to 15%, including a proposed 3 phase cycle, along the description of heat

exchangers, microturbine, generator and compressor wich need to be designed for

further projects.

Keywords: Triple Phase cycle, CO2, OTEC, 3P sCO2, OTEC Plant

IOS8MX046-OT-R

Numerical Simulation of the Evaporator for the OTEC Plant

Prototype for 1 kWe on the Mexican Caribbean.

Bryant S. Delgado D., Erick Perez S., Emiliano Carrillo C. and Víctor M. Romero M.

Department of Engineering and Basic Sciences, Universidad del Caribe, Esquina Fraccionamiento, Tabachines, 77528 Cancún, Q.R.

vromero@ucaribe.edu.mx

ABSTRACT

There are different types of renewable energies that are obtained directly from

nature, such as solar, wind, nuclear, geothermal and marine. From the latter, energy

can be obtained through waves, ocean currents, the saline gradient and the thermal

gradient. Currently the thermal gradient has acquired a special interest because it

is present throughout the year, so in recent decades experimental plants have been

developed that take advantage of this type of energy with very satisfactory results,

these plants are known as Conversion of Oceanic Thermal Energy (OTEC). In

Mexico, the Mexican Center for Energy Research - Ocean (CEMIE-O) was created

in which the University of the Caribbean, through the Academic Body on Energy

Systems and Sustainability (CASES, for its acronym in Spanish), is an active

collaborator. At the CASES, the first prototype of a 1 kWe OTEC plant for the

Mexican Caribbean Sea is being developed. This OTEC plant is of the closed cycle

type in which a working fluid that requires low temperature for the phase change

from liquid to vapor is used. For this prototype, after an exhaustive evaluation it was

decided to use the R152a refrigerant as the working fluid for its characteristics of low

impact both environmental and human health. This OTEC plant has 4 fundamental

processes, each of them related to the Rankine thermodynamic cycle. Each process

is developed by each of these components: (1) Bomb, (2) Evaporator, (3) Turbine

and (4) Condenser. In this work the results of the evaporator simulation are

presented, this will allow us to have a better understanding of its operation by

controlling the parameters of the phase change process of the working fluid (R152a)

within a controlled environment, we also determine the number of plates needed in

the evaporator to obtain 100% saturated steam as well as their thermodynamic

conditions at the evaporator outlet that will be transferred to the turbine; for the

simulation we are using the commercial computational fluid dynamics program

known as ANSYS FLUENT. The methodology used for the simulations is

encompassed in four main steps: (1) geometric design, (2) discretization of the

control volume, (3) definition of material properties, boundary conditions and

simulation, and (4) analysis of results. The geometry used corresponds to the MWFD

model flat plate evaporator with M6-FD type plates from Alfa Laval Company. The

methodology was applied to the control volume corresponding to that of the R152a

fluid. The first simulation was carried out for a 4-plate heat exchanger, later

simulations were carried out increasing the number of plates in multiples of 10 until

obtaining 100% of R152a saturated vapor at the evaporator outlet. The results will

be compared with the real exchanger of the prototype. Finally, after carrying out a

numerical simulation of a four-plate heat exchanger, the results showed that only

7% of the refrigerant was converted into steam, so it is necessary to continue with

the methodology increasing the number of plates until obtaining the optimum

quantity to obtain 100% of the vapor volume fraction.

Keywords: Numerical Simulation, Plate Heat Exchanger, Evaporation, OTEC,

Ansys Fluent

IOS8MX027-OT-S

Horizontal shell and tubes heat exchanger in OTEC Ammonia

energy loop

Dr. B.Clauzade, Dr. D.Mas

Naval Energies, Route d’Indret, 44620 La Montagne, FRANCE

bclauzade@naval-energies.com

ABSTRACT

Experimental studies of the OTEC Ammonia Rankine Cycle exchangers have

highlighted the good performance of horizontal shell & tube evaporators and

condensers. This design allows good performance with low pressure drop of

seawater fluid and easy maintainability of the inner tube exchange surface. Basic

thermo-hydraulic performance of those smooth tubes units can be increased

through the use of improved tubes in the condenser and/or the evaporator. Our PAT

ETM test bench in Reunion Island designed in 2011 has allowed us to test with

Ammonia, different types of exchangers (plate heat exchangers, flooded shell & tube

exchangers, falling film shell & tube exchangers) with models around 25m², and

heat load up to 450kW. The European organization OCEANERA-NET allowed us to

test the best exchanger designs, with different types of improved tubes on the

INNOTEX (Innovative Thermal Exchanger) project. Several tubes have been chosen

for their internal tube performance (single phase) and/or their external tube

performance, in condensation regime (drainage effect) or in evaporation (developed

surface effect, nucleation effect, dynamic retention effect). We present here the

main thermo-hydraulic results for an overall assessment of the electrical

performance of the OTEC cycle.

Keywords: OTEC, thermal efficiency, big size heat exchangers, enhanced tubes,

Ammonia

IOS8MX044-OT-S

Sensitivity analysis of the OTEC-CC-MX-1kWe prototype

Jessica Guadalupe Tobal Cupula, Estela Cerezo Acevedoa, Yair Yosias Arriola Gila,

Víctor Manuel Romero Medinaa and Héctor Fernando Gómez Garcíaa

a Departamento de Ciencias Básicas e Ingenierías, Universidad del Caribe. SM 78, Mza. 1, Lote 1, Esq. Fraccionamiento Tabachines, 77528, Cancún,

Quintana Roo, México.

*Corresponding Author: ecerezo@ucaribe.edu.mx

ABSTRACT

In this work is presented the sensitivity analysis of OTEC-CC-MX-1kWe prototype,

that was evaluated using monthly mean temperatures from 2015 to 2019. The

prototype is located at Universidad del Caribe, it works with a closed OTEC cycle,

its main components are: an evaporator, a condenser, a pump, a generator turbine

and two auxiliary heating and cooling systems, which simulate the surface and

subsurface sea temperature, respectively. For this analysis, surface and subsurface

temperature data for the Mexican Caribbean Sea was used, which was obtained

from two different models: The Hybrid Coordinate Ocean Model (HYCOM) and

Geographically Weighted Regression Temperature Model for the Mexican

Caribbean Sea (GWR-TMCAS). Inlet and outlet temperatures of heat exchangers,

for water and working fluid, were assessed using this temperature data and the

logarithmic mean temperature difference of the evaporator and the condenser (8.5

°C and 3.5 °C, respectively). The mass and energy balance of the Rankine cycle

was carried out considering stationary operating conditions, and insignificant kinetic

and potential energy changes. Results show that the highest mean surface

temperature (29.2 °C) occurs during summer and autumn months, having the

maximum in October (29.5 °C), whereas the lowest mean surface temperature

occurs in winter months, having the minimum in February (26.8 °C). The temperature

gradient varies along the year between 19.6

°C and 22.6 °C. The highest Carnot efficiency is presented in September for both

models, which values were 7.3% and 7.9% for HYCOM and GWR-TMCAS,

respectively. The thermal efficiency evaluation indicates the highest value (2.7%) at

the month with the highest thermal gradient, September, while the lowest value

(2.28%) is presented as in January as in December. The amount of water mass flow

at the evaporator is equal for both models, the highest mass flow (6.8 kg/s) is

required in the month with the lowest thermal gradient (February) and the lowest

mass flow is required in the month with the highest thermal gradient (September).

The water mass flow at the condenser suggests that GWR-TMCAS is closer to real

operation conditions that HYCOM. The sensitivity analysis for the working fluid mass

flow indicates that this amount is similar for both models, the maximum flow is

observed in December (0.16 kg/s) and the minimum flow in May (0.13 kg/s).

According to this analysis, it is concluded that OTEC-CC-MX-1kWe prototype can

generate 1 kWe, even though the temperature gradient is not equal to 20 °C for

each month. Laboratory tests on the prototype will be carried out in future works, in

order to compare this sensitivity analysis and to evaluate the prototype operating

and performance limits regarding thermal gradient variation.

Keywords: OTEC, HYCOM, GWR-TMCAS, thermal gradient, organic Rankine,

working fluid.

Organized by:

8th International OTEC Symposium

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