Integrated Desert Building Technologies (IDBT)

transcript

Integrated Desert Building Technologies

(IDBT)

Ezzat Fahmy

Amr Serag-Eldin

Ehab Abdel-Rahman

THE AMERICAN UNIVERSITY IN CAIRO

Integrated Desert Building Technologies is a joint project between the American University in Cairo (AUC) and King Abdullah University for Science and Technology (KAUST)

The Project Aims at Transfer, Development, Adaptation, and Integration of technologies in such fields as: Architecture, Structure, Materials And Construction, Energy Generation and Conservation, Water Management and Re-use, and Life Cost Analysis.

IDBT AUC Research Team

• Medhat Haroun (Principal Investigator)• Ezzat Fahmy ( Material & Structures )• Mohamed Abdel Moaty( Mat & Structures)• Mohamed Naguib (Material & Structure)• Ed Smith ( Water management & re-use)• Emad Imam( Water management & re-use)• Ehab Abdel Rahman( Energy Generation and

Conservation)• Amr Serag-Eldin( Int. Energy systems)• Ahmed Sherif( Architecture)• Osama Hosny (Life cost cycle)

CURRENT AND FUTURE PHASES OF

THE PROJECT

CURRENT AND FUTURE PHASES OF

THE PROJECT

Phase IDevelopmental

Studies

Phase IDevelopmental

Studies

Phase IIDemonstration

and Monitoring

Phase IIDemonstration

and Monitoring

Saudi Arabia, Egypt, and the

Arab World

Saudi Arabia, Egypt, and the

Arab World

KAUSTKAUSTAUC/KAUSTAUC/KAUST

Phase IIIPractical

Implementation

Phase IIIPractical

Implementation

ASPECTS OF EFFICIENT DESERT BUILDING DEVELOPMENT

Elements of the First Phase

Integrated Energy Systems in IDBT

Amr Serag-Eldin

Sustainability

• The IDBT project places special emphasis on Sustainability.

• Sustainability implies that future generations will be able to continue enjoying current living standards despite the reduction of fossil fuels and non-renewable energy resources.

• Like most future building technologies it aims at reducing energy consumption without compromising indoor quality.

• However, it goes one step further; it considers localized energy conversion from available RE resources.

• The desert environment offers both challenges and opportunities, which the proposed design addresses

Classification of Energy Loads

• Heat Loads:– Cooling loads: Air-conditioning– Cooling loads: Refrigeration for preservation & cooling of

food and beverage– Heating loads: Cooking– Heating loads: Occasional indoor heating (winter nights?)– Heating Loads: Domestic hot water (bathrooms, kitchen,

dish/clothes-washers)

• Electrical Loads:– Lighting– Appliances (computer, TV and multimedia, hair-dryers,

dish/clothes washer motor, etc.. ; refrigerator and ovens have been added to heat loads)

• Mechanical Loads:– Air circulation (ventilation & fans)– Water circulation and deep-well pumping.

Special DBT Features

• A/C load is expected to be the highest, particularly in summer daylight hrs.

• Minimum water consumption is allowed.• Hostile environment (sand storms)• Most abundant source of RE is Solar• Night time temperatures much lower than daytime

temperatures• Sun light hours don’t vary much year round• Wind energy is site dependent and should not be

depended upon entirely.• A/C loads and Solar energy are in phase in year cycle.

Energy System Design Guidelines

1. Reduce loads and conserve energy : particularly A/C loads.

2. Exploit locally available RE resources, particularly Solar (attempt zero conventional).

3. Extend use of available RE resources by introducing both thermal and electrical energy storage.

4. Design should not be too site specific; it should reflect the most common features of ME desserts. Thus biogas and desalination ruled out.

5. Design should provide a healthy, comfortable, and productive environment at minimum cost.

6. It should be reliable, durable, user friendly, as well as environmentally friendly.

Proposed Energy System

Considers Energy:

– Conservation: Double-cavity-walls and reflective cladding, roof insulation and overhangs, ground insulation; smart windows; LED lighting; displacement ventilation; H.E. between fresh and discharge air; use of evaporative cooling

– Conversion: Fresnel-mirror collectors/Absorption refrigeration, WECS, Photovoltaics, Wind-ventilator, Parabolic-dish/ Thermoacoustic-engine/refrigerator, flat-plate collectors

– Storage : Chiller water storage, Hot water storage, Battery

Fresnel collector principle

A Fresnel Mirrors System

A/C Absorption Chillers: Ammonia/water

A/C Absorption Chillers :H2/Ammonia

Displacement .vs. Dilution Ventilation

CO2(ppm) in cross-planes

T(oC) in cross-planes

WIND DRIVEN VENTURI-VENTILATOR

DEVELOPED EMPLOYING CFD

A Model was built

Tested and validated in W.T.

A Full Scale Prototype was Built

1. Develop prototype to operate under field conditions : introduction of a self-alignment mechanism.

2. Test prototype under varying wind speed and direction.

3. Long term testing on a roof-top under actual/near-desert operating-conditions.

4. Integrate Wind ventilator in the architectural design .

5. Integrate it in the energy system, e.g. with thermal storage and passive cooling and heating systems.

Prototype for Testing

Parabolic Dish/Thermo-acoustic Engine

Thermo-acoustic Engine/Refrigerator

Mechanical Sterling Engine

Free-piston Sterling Engine

Thermo-acoustic Engine

CFD Simulation : background

• Thermo-acoustic engines/refrigerators are currently designed using simple thermo-acoustic theory subject to Rott’s acoustic approximations; which are justified for weak pressure waves (small amplitudes) and semi one dimensional geometries.

• Our research is investigating applications with 10% or higher pressure amplitudes in 2/3 -dimensional geometries, and large dimensions with possibility of flow turbulence (requiring turbulence models).

• We don’t want our designs to be constrained by the capabilities of our prediction models. Thus we need to go to the most general computational tools, namely CFD commercial S/W.

• CFD solves sets of multi-dimension, partial-differential, non-linear eqns.; very different from Rott’s wave equations. Solution time and computational requirements are several orders of magnitude higher.

CFD Solutions : Challenges & Solutions

Challenges:• Very fine spatial grids covering large volumes, are

required to capture the phenomena occurring , and for several cycles.

• Formulation of boundary conditions requires special attention in order to reflect the physical situation as close as possible.

Solutions:• Use parallel processors and parallelized CFD S/W. A

single user version PHOENICS is temporarily set-up, until cluster of computers are connected.

• Use of higher order discretization methods in order to get high accuracy with a reasonable grid size. Ongoing attempts to introduce in code.

Alternative Design

• From a thermodynamic point of view, it is NOT efficient to convert EE into HE; however from an economic /practicality point this may not be so.

• Comparison will be made between an energy system based entirely on photovoltaic cells (converting some of EE into heat) and the one proposed here.

• Comparison includes life cycle costs, projected reliability, ease of maintenance and repair and local manufacturing opportunities

Summary & Conclusion for Energy component in DBT

• An investigation was conducted to examine typical energy needs of a desert building. Special desert features were identified and a conceptual integrated energy system design presented.

• The design in addition to being efficient in energy conservation, will also produce its own energy needs by converting readily available local solar energy, supplemented by any available wind energy.

• Future work will involve detailed calculations, equipment selection and specification as well as performance estimates. Moreover, the proposed design, which employs novel techniques and non-conventional technologies, will be compared against one which relies only on photovoltaic cells to meet its energy requirements.

Thermoacoustic Devices for Harvesting Energy from Solar

Energy & Waste Heat

Ehab Abdel-Rahman

Department of Physics, AUC

Yousef Jameel Science and Technology Research Center, AUC

What is Thermoacoustic?

• Thermoacoustics (TA) is the study of the conversion of acoustic energy into heat energy and vice versa

• Acoustic energy can be harnessed in sealed systems and used to create powerful heat engines, heat pumps, and refrigerators.

Components of Heat Pump &

Prime Movers

Components of Heat Pump &

Prime Movers

• Thermoacoustics is the study of temperature fluctuations in an acoustic field

• A Thermoacoustic refrigerator harnesses the thermoacoustic effect to move heat

What a Gas Parcel Does

1) Expands and Cools2) Draws Heat from Plate3) Contracts and Heats4) Expels Heat to Plate

How does it work?

Application

How does it work?

History of Thermoacoustic

Byron Higgins, 1777

Sondhauss, 1850

Rijke, 1859

Lord Rayleigh

Rott, 1969

Wheatley and Swift, 1983

Symko and Abdel-Rahman 2002

Glass Blowers

The first successful theory of

thermoacoustic

If heat to be given to the air at the moment of greatest condensation or

taken from it at the moment of greatest

refraction, the vibration is encouraged (1887)

built the first TAR

Harvesting Energy!!

• TA Devices can use Solar Energy to Produce cooling

• TA Devices can use waster heat / solar energy to produce electricity

Solar Energy Driven TA Refrigerator

Concentrator

Prime MoverSunlight Heat

TA Refrigerator/ linear Alternator

Cooling/

Electrical

Solar Energy Driven TARefrigerator / Concentrator

0 0.005 0.01 0.015 0.02

(Tin-Tamb)/ (Ieff) ( oC m2/ W)

ambinRLRo

Solar Energy Driven TARefrigerator / Prime Mover

Time (sec)

-0.002 -0.001 0.000 0.001 0.002

Sound P

ressure

Fluctuations Coherent Oscillations

Time (sec)

-2 -1 0 1 2

Solar Energy Driven TARefrigerator / Refrigerator

0 4 8 12

P1/Pm=0.2%P1/Pm=0.35%P1/Pm=0.6%P1/Pm=1%P1/Pm=3%

Time (sec)

Conversion of Waste Heat / Solar Energy into Electricity

Dreams and Reality

• Several devices have been developed

• New designs are under study

Achievements

SIZES!!!

Summary

Harvesting Waste Heat and Solar Energy

Via Thermoacoustic Devicesis a promising technology

ENERGY CONSERVATION

Tunable Photonic Smart Windows

29 Layers

ENERGY CONSERVATION

Tunable Photonic Smart Windows

9 Layers

AcknowledgementAcknowledgement

• This project is Funded by King Abdullah for Science and Technology (KAUST)

• Prof. Amr Shaarawi, AUC, Egypt

• Mr. Mustafa Nouh

• Mr. Nadim Arafa

• Mr. Ahmad Adawy

• Mr. Michel Rezk

• Mr. Mohmad Beshr

Integrated Desert Building Technologies (IDBT)

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