Feb 7, 2012

Term 8 Senior Design Project

Sustainable Water Desalination

Tuesday February 7, 2012

Feb 7, 2012Slide 2

Project Team

Team Members:

Mission Statement:

“Our mission is to use problem solving and analytical abilities, building upon knowledge from engineering course work and work terms, to design and build a simplistic prototype for a sustainable water desalination device. This device will utilize energy captured from the environment whenever possible while maintaining a robust design for use in a developing nation.”

Team Website:

http://mundesalination.weebly.com/

Clare O’Keefe

Chris Humphries

Whitney Miller

Jared Osmond

Andrew McHugh

Feb 7, 2012Slide 3

Agenda

• Project Overview

• Preliminary Research

• Concept Selection Process

• Preliminary Engineering

• Forward Plan

Feb 7, 2012Slide 4

Project Scope

Project Goal:• Design and develop a water desalination device for implementation in

underprivileged coastal areas

Design Necessities:• Minimize moving parts• Minimize power input requirements• Eliminate skilled labour and specialized equipment requirements• System does not otherwise reduce quality of water

Project MetricsProduct Life 5 YearsProduced Water 30-50 L / dSodium Concentration 200 mg / LOperational Availability 12 hr / dWeight 100 kgCAPEX Proof of Concept $ 1000 CAPEX Production Model $ 500 OPEX Production Model $ 100

Feb 7, 2012Slide 5

Project Considerations

Safety

Risk

People

Feb 7, 2012Slide 6

Project Schedule

• Currently in Design Phase• Construction Phase: Proof of concept (scale or partial model) • Testing Phase: Benchmarking to evaluate design

Feb 7, 2012Slide 7

Preliminary ResearchDesalination

Solar Distillation Reverse Osmosis

Multi-Stage Flash Process

Feb 7, 2012Slide 8

• Eliminated multi-stage flash due to inherent complexity• Completed concept selection process with selection matrix approach

• Key Considerations: • Reverse Osmosis: Filter change-out and spoiling• Reverse Osmosis: High pressure requirements • Solar Distillation: Lower production rates • Solar Distillation: Base system requires no moving parts

Selected Concept: Solar Distillation

Concept Selection Process

Feb 7, 2012

Preliminary Engineering

Slide 9

Feb 7, 2012Slide 10

Evaporation and Condensation

Steady state system: Evaporation Rate = Condensation Rate

Optimize Evaporation and Condensation Maximize Production

How?• Maximize water temperature• Minimize condensation surface temperature• Maximize water surface area• Reduce atmospheric pressure

Feb 7, 2012Slide 11

Efficiency Improvements

Increase Water Temperature:• Colour Water Increases water ability to absorb radiant energy• Solar Concentrators Directs additional solar radiation

Increase Condensation Rate:• Cool Surface Increases condensation rate at surface

Increase Active Area:• Wicking/ Capillary Action Increases exposed surface area• Air Flow Increases evaporation rate

Increase Evaporation or Promote Boiling:• Vacuum Reduces pressure on surface, lowers boiling point

Feb 7, 2012

Prior Art

Slide 12

Heat Sink:• Used to store heat• Stones submerged in water• Stones retain heat as water is evaporated or cycled through the system

Basic Design:• Greenhouse type geometry

SOLAR ENERGY

EVAPORATION / BOILING

HEAT SINK

FRESHWATER

BRINE

Feb 7, 2012Slide 13

Prior Art

Multi-Basin:• Two condensation surfaces• Maximizes per m2 output

Water Boiler:• Reduce system atmosphere• Additional solar flux

Feb 7, 2012Slide 14

Prior Art

• Cascade / Step Configuration:• Minimizes distance between water and condensation surface

• Two Stage E/C System: • Potential for significant cooling of the condensation section• Lower efficiency – humid air is expelled

Feb 7, 2012Slide 15

Forward Plan

Feb 7, 2012Slide 16

References

• Cortuvo et al, Desalination Tehnology - Health and Environmental Impacts.: IWA Publishing.• (2010, December) Health Canada. [Online].

http://www.hc-sc.gc.ca/ewh-semt/pubs/water-eau/2010-sum_guide-res+recom/index-eng• A.G., Govet, C. Dickson. (1994) Chapter 5 - Physical and Thermodynamic Data. [Online].

http://cdiac.esd.ornl.gov/ftp/cdiac74/chapter5.pdf• Uri Lachish. (1998) Vapor Pressure, Boiling and Freezing Temperatures of a Soluation. [Online].

http://urila.tripod.com/colligative.htm• S. Grajdieru. (2003, March) Solar-powered Desalinators to Provide Drinking Water in Arid Areas. [Online].

http://web.idrc.ca/en/ev-3178-201-1-DO_TOPIC.html• (2011) Small Scale Desalination. [Online]. http://www.desware.net/Small-Scale-Desalination.aspx• (2010) Multi Stage Flash Processes. [Online]. http://www.sidem-desalination.com/en/process/MSF• (2011) Canadian Mortgage and Housing Corporation. [Online].

http://www.cmhc-schl.gc.ca/en/co/maho/wawa/wawa_001.cfm• R. Shaw, Wave Energy: A design Challenge, Horwood, Ed. Chichester: 1982.• (2007, April) Mechanical Ocean Energy Conversion, Part II. [Online].

http://montaraventures.com/energy/2007/04/13/mechanical-ocean-energy-conversion-part-ii/• (2007, April) Stephen Salter: pioneer of wave power. [Online]. http://www.theengineer.co.uk/in-depth/stephn-

salter-pioneer-pf-wave-power/299034.article#ixzz1Z6VLv18f• M.E. McCormick, Ocean Wave Energy Conversion. New York, USA: Wiley, 1981.• P. Takahaski, Ocean Thermal Energy Conversion. New York, USA: Wiley, 1996.• (2004, November) Ocean Thermal energy conversion diagram and applications. [Online].

http://www.nrel.gov/otec/• M. Jacobson. (2008, January) Review of Solution to Global Warming, Air Pollution, and Energy Security.

[Online]. http://www.stanford.edu/group/efmh/jacobson/EnergyEnvRev1008.pdf• Saturated Vapor Pressure. [Online]. http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/vappre.html#c1• S.A. Kalogirou, Solar Energy Engineering - Processes and Systems.: Elsevier, 2009.• M.K. Gnanadason, P.S. Kumar, G. Sivaraman, and J.E. Daniel, "Design and Performance Analysis of a Modified

Vacuum Single Basin Solar Still ," Smart Grid and Renewable Energy, no. 2, pp. 388-395, September 2011.

Feb 7, 2012

Questions?

Thank You!

Slide 17

Feb 7, 2012

BACKUP

Slide 18

Feb 7, 2012Slide 19

Multi Stage Flash

Feb 7, 2012Slide 20

Solar Still Production Theory

• Correlations developed for modeling simple solar stills:

• Includes some experimental parameters Requires testing of constructed prototype

• Relations can be used to identify areas to exploit: