Engineer Fahad Hasan Associate Yousuf Hasan Associates, Consulting engineers

1. Engineer Fahad Hasan Associate Yousuf Hasan Associates, Consulting engineers District cooling

2. Introduction • District Cooling • Components • Central Plant • Distribution Network • Consumer System

3. Pros&Cons of District Cooling • More efficient due to simultaneous production of cooling and electricity • Long term commitment • More beneficial for area with high population density

4. The Central Plant • Selection Criteria • Environmental Impact • Efficiency, COP, IPLV • Useful life • Initial cost • Running cost • Availability • Maintainability

5. Chiller efficiency rating • Coefficient of performance • kW/TR for Peak Ratings • Integrated Part Load Value • Nonstandard Part Load value • Multiple Chillers

6. Refrigerants

7. Refrigerants

8. Water Chiller Comparison

9. Reciprocating Chiller • Typically uses R22 but also available with R134a and R717 • Larger machine with multiple compressors • Lower first cost but higher initial cost • Control is achieved by stepping unload and cycling compressor on/off

10. Screw Chiller • Positive displacement machines • Typically uses R22, R134a, R410a & R717 • Available with single screw and twin screw compressor • Having fewer moving parts

11. Centrifugal Chiller • Centrifugal chillers have highest full load efficiency rating of all the chillers discussed • Uses high pressure refrigerant R22 and R134a & low pressure refrigerant R123 • Air cooled & water cooled are available but due to very low COP and very high initial cost air cooled centrifugal chillers are very seldom used.

12. Absorption Chiller • Absorption chiller can be single effect or double effect. • Double effect absorption chillers are more efficient than Single effect absorption chiller while Single effect is beneficial where low quality steam or hot water available

13. Engine Driven Chiller • Uses same vapor compression cycle as electric chillers except it uses reciprocating engine or gas or –steam driven turbine as prime mover. • Range of refrigerants may be used including R22, R123, R134a and R717

14. Combined heat & power (CHP) • CHP is simultaneous production of electricity and heat from single source fuel i.e. natural gas, biogas, biomass, coal, waste heat or oil. • Typically waste heat of gas turbine or engine via waste heat recovery boiler and heat exchangers and utilized to operate absorption chiller • Multi-energy chillers directly fed by flue exhaust of the engines

15. Benefits of CHP • Efficiency Benefit

16. Benefits of CHP • Reliability Benefit • Combined heat and power (CHP) systems, when properly designed, provide critical power reliability for a variety of businesses and organizations while providing electric and thermal energy to the sites on a continuous basis, resulting in daily operating cost saving.

17. Benefits of CHP • Environmental Benefit • Combined heat and power (CHP) system offer considerable environmental benefits when compared with purchased electricity and onsite generated heat. By capturing and utilizing heat that would otherwise be wasted from the production of electricity, CHP systems requires less fuel than equivalent separate heat and power systems to produce the same amount of energy.

18. Benefits of CHP • Economic Benefit • Reduced Energy Costs • Protection of Revenue streams • Hedge against volatile energy prices

19. Conclusion • Long tern commitment • Requires careful design • Advance flue gas cleaning • Attention must be given to; • environmental impact, • COP & IPLV • Initial cost & Running cost • Useful life & Maintainability • The benefits of CHP and/or thermal storage with district cooling system becomes more prominent as compare to decentralized small cogeneration and/or thermal energy storage plants due too larger size of plant