1. ROAD TO CLIMATE FRIENDLY CHILLERS Hydrocarbons & Absorption Chillers Systems: Development & Potential Dr. Alaa Olama Sept. 2010, Cairo, Egypt

2. CONTENTS: 1- Hydrocarbon fired Absorption Chiller & Heat ratio 2- Difference between HR (COP) Abs. & COP V.C. 3- How did H.R (COP) improve dramatically. 4- Conclusion

3. 1- Hydrocarbon Fired Absorption Chiller & Heat Ratio

4. ＣＯＰ (LP) ＝ （ Refrigeration capacity ／（ Gas Low calorific value ＊ Gas consumption ） ＣＯＰ (HP) ＝ （ Refrigeration capacity ／（ Gas High calorific value ＊ Gas consumption ） Definition of COP (HR) of Absorption Chillers

5. 2- Difference between HR (COP) Abs. & (COP) V.C.

6. Overall efficiency of a power station: SType of Power StationsPercentage (%) 1Best combined cycle Steam turbines carry the base load & gas turbines carry the variable load (peak load) 55 2Steam cycle40 3Simple cycle30-35 4Transmission Losses10 * Efficiency at Refrigeration plant boundary becomes 25 to 50 %

7. Comparing chillers efficiencies: COP mv c 456 Station & transmission efficiency 253035502530355025303550 COP abs 11.21.421.251.51.752.51.51.82.13

8. 3- How did H.R (COP) improve dramatically

9. History of absorption chiller-heater History of development for Gas direct fired absorption chiller 2005.2 Kyoto Protocol ０. ７５ ０.80 ０.93 ～ 0.96 1.07 1.1 1.2 1.3 1.35 1.6 以上

10. H.R (COP) Improvement

11. Key technology to improve the efficiency 3.Dual absorption Dual evaporation 4.Condensed refrigerant heat-exchanger 1.Improved solution heat-exchanger 2.Refrigerant Cooler 5.High performance heat transfer tube RCD 6.Exhaust heat-exchanger RFD 7.Larger Heat transfer area on ABS. EVP. 8-Efficiency improved on High stage GEN. RED

12. Internal piping flow of RFD （ chiller ）

13. 1- Improvement on efficiency of solution heat-exchanger Shell & Tube type heat-exchanger Solution heat-exchanger High temp Low temp. Plate heat-exchanger ☆ Advantage ・ Better heat transfer performance compared to S&T ◎ More compact ・ Less solution retained ☆ Advantage ・ Better heat transfer performance compared to S&T ◎ More compact ・ Less solution retained Key technology of improvement

14. 2- Refrigerant cooler ↓ 33 ℃ Key technology of improvement Cooling down the refrigerant back from condenser, to reduce the load on Generator, to get better efficiency Ref. cooler EVP. (9 ℃ ) 38 ℃ ABS. Cooling W CONDS. Refrige rant 37 ℃ 32 ℃ 36.5 ℃

15. Upper stage ： Low pressure in ABS. / EVP. Lower stage ： High pressure in ABS. / EVP. ☆ Advantage ☆ Advantage Bigger concentration difference of solution, by separating ABS. & EVP. to 2 stages Enable to reduce circulating flow Less heating calorie at Generator, thus better efficiency 3- Dual Absorption, Dual Evaporation Cycle Key technology of improvement

16. 4- Condensed refrigerant heat-exchanger Key technology of improvement Weak solution Condenser （ 38 ℃） Low temp. H-exchanger Low stage GEN. High temp. H-exchanger S.P. High temp. Refrigerant back from low GEN. and weak solution, Heat recovery on High temp. Refrigerant back from low GEN. and weak solution, to get better efficiency 44 ℃ Condensedrefrigerant Condensed refrigerant heat-Exchanger 90 ℃ Heat from Low GEN. ⇒ Steam from High GEN. 78 ℃ 36 ℃

17. 5- High Performance heat transfer tube Key technology of improvement

18. Exhaust Natural Gas Air supply 20 ℃ High GEN. pre-heating the air supply to the Burner. The gas consumption reduced by pre-heating the air supply to the Burner. 6- Exhaust heat-exchanger （ Air pre-heater ） Key technology of improvement 165 ℃ 75 ℃ 155 ℃ Air Pre- heater

19. Key technology of improvement 7- Larger Heat transfer area on ABS. EVP.

20. Key technology of improvement 8- Efficiency improved on High stage GEN.

21. Improved solution heat-exchanger Exhaustheat-exchanger increased KA value, on CND. ABS. Refrigerant cooler COP 1.22 COP 1.00 Solution flow regulation RED Improved solution heat-exchanger +0.085 +0.015 RFD +0.04 +0.015 +0.02 Dual ABS. / EVA. +0.02 Large head of chilled water （ Δ8 ℃） Condensed ref. heat-exchanger +0.05 ＋ +0.035 Efficiency improved High GEN. COP 1.29 COP1.29 Designed based on COP1.29 machine COP 1.35 Exhaustheat-exchanger +0.06 COP1.35 Exhaust heat- exchanger Reached COP1.35 with Exhaust heat- exchanger Key technology of improvement Improvement of COP by each technology

22. 4- Conclusions

23. Conclusions:- 1- When comparing The overall thermal efficiencies,it is important to compare the efficiency of mechanical vapour compression systems (electric chillers) to the efficiencies of vapour compression systems ( absorption chillers), starting at the boundary of supply to the power station(natural gas ) and the boundary of supply of natural gas at the absorption chillers burner, otherwise the comparison cannot be fair. 2- When this is done,the difference in efficiencies is then quite close, taking into consideration that few power stations in Egypt have high thermal efficiencies. 3- Therefore the use of natural gas in large central air conditioning projects is economically sound since the saving in investment cost for power plant is considerable. (1)

24. Conclusions(Cont.):- 4- Shaving electrical peak loads in summer can only be achieved by the use of natural gas fired air conditioning system. 5- legislation exists in many countries that prohibit the use of electrical energy in air conditioning over a certain refrigeration tonnages (over about 1000 TR) This is the case in Japan, South Korea & lately the United Arab Emirates. The aim of the legislation is to preserve electric power for applications where there are not other alternative sources of energy. (2)