1. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS DH Jeggels and RT Dobson Department of Mechanical Engineering, University of Stellenbosch, Stellenbosch, Western Cape Province, South Africa Dawood Jeggels and RT Dobson presentation for EPC2013 as at 8 August 2013 Theoretical and Experimental Simulation of a Li-Br Water Dual Function Absorption system 1

2. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 2 Preamble  The world, in general, has become very aware of the fact that we are polluting the planet irreversibly; “you don’t get nothing for free” so if “If it isn’t green, paint it green”.  Environmental impact studies, global warming, ozone depletion, pollution, renewable energy such as solar, “CSP”, wind, tidal, hydroelectric and waste minimization have all become important words in both business and academic circles.  Power utilities and big-business must be seen to be saving energy, generating power more efficiently, reducing their carbon footprint, and reducing their production of polluting and global warming effluent/waste/toxic materials.

3. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 3 Pre-amble (cont.)

4. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 4 Pre-amble (cont.) Thermal efficiency as a function of heat source temperature 14% of 100°C waste heat can be recovered using a DFAC Stirling cycle engine (SC) Rankine cycle (RC) Dual function absorption cycle (DFAC)

5. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 5 Contents Preamble Why a dual function absorption cycle Objectives: To build and test an absorption system that can be used to get a better understanding of its functioning and control strategies and to assist in validating the theoretical simulation model of the cycle Experimental Apparatus Transient theoretical modelling Discussion, Conclusions and Recommendations

6. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 6 Dual function (power and refrigeration) ammonia-water (or Li-Br water) absorption system Power Refrigeration Cooling water Waste heat supply How does it work

7. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 7 Experimental apparatus Stand, generator and condenser Heat exchangers Evaporator and absorber

8. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 8 Theoretical Simulation Process

9. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 9 Results For example, for the Generator-Condenser, and similarly for the rest

10. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 10 Discussion, Conclusions and Recommendations We have shown what an absorption cycle works and how it can generate both power and cooling using a low-grade (low temperature) source of (waste) heat We have shown how we mathematically simulate such a system We have so far completed the generator-condenser/turbine part, the absorber-evaporator, the pump. We have manufactured the parts but still need to complete the assembly of the system parts

11. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 11 Acknowledgements South African Heat Pipe Association University of Stellenbosch Thank s

12. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 12 Condenser Stand Generator Back

13. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 13 Heat exchangers Back

14. SAHPA ® South African Heat Pipe Association Energy Postgraduate Conference EPC2013, 11-14 Aug 2013 iThemba LABS 14 Evaporator and absorber EvaporatorAbsorber Back