Trane TRG-TRC011-EN manual Combination Chiller Plants

Page 60

period five

Application Considerations

notes

									operate
									absorption
									chiller
load		operate																	operate
cooling		electric																	electric
		chiller																	chiller

1	2	3	4	5	6	7	8	9	10 11 12	1	2	3	4	5	6	7	8	9	10 11 12

on-peak

period

Figure 63

Combination Chiller Plants

Absorption chillers possess two operating characteristics that can noticeably improve overall system efficiency and reduce system energy costs.

First, absorption chillers use fossil fuels rather than electricity. Operating absorption chillers at times when on-peak electric energy and/or demand costs are high reduces total system utility costs. In such installations, the absorption chiller can operate during on-peak periods to avoid the high cost of electricity. The electric chiller can run during off-peak periods to take advantage of the lower cost of electricity.

Combination gas-and-electric plants can also exploit the heating capability of direct-fired absorption chillers. Both electric and absorption chillers can be used to provide summer cooling. If the electric chiller is large enough to satisfy the entire winter cooling load, the direct-fired absorption chiller can be switched to heating operation to either satisfy the entire winter heating load or supplement the primary heating equipment. In such applications, selection of the direct- fired absorption chiller should be made to allow downsizing, or perhaps even elimination of, the primary heating equipment.

TRG-TRC011-EN

55

Image 60

Contents Air Conditioning Clinic Absorption Water Chillers Absorption Water Chillers Preface Contents TRG-TRC004-EN Introduction TRG-TRC011-EN Absorption Refrigeration Cycle Period onePeriod one Reject heat Heat energy Absorption System Fluids High affinity for water refrigerant Components of the Absorption Cycle Conditions Steam or Hot waterrefrigerant vapor Generator Condenser Refrigerant then flows into the evaporator pan Absorber spray pump Solution Heat Exchanger Dilute Generator pump Equilibrium Chart Heat Solution temperature Absorption Chiller Types Period twoSingle-Effect Chiller Absorber Evaporator spray pump Spray pump Generator pump Double-Effect Chiller Vapor Low Temperature condenser Cooling Generator Water Evaporator Absorber Low-temperature generator pump Generator pump Absorption Chiller Types Direct-Fired Chiller Evaporator High-temperature high-temperature Generatorgenerator pump Chiller/Heater Absorption Chiller Types Changeover Absorption Chiller Types Capacity Control Period threePeriod three Energy valve Generator Crystallization 10C 37.8C Capacity Control Capacity Control Capacity Control Heat exchanger bypass Evaporator pan Purge System Isolation valve Maintenance Considerations Period fourPeriod four Maintenance Considerations Test run with alternate fuel, if dual-fuel burner Maintenance Considerations Maintenance Considerations Corrosion inhibitor and performance additive recommendations Application Considerations Period fiveCooling-Water Temperature Limitations Combination Chiller Plants 58F Special Considerations for Direct-Fired Chillers Application Considerations Equipment Rating Standards Review Period sixPeriod six Review Review Review Quiz Questions for PeriodQuiz TRG-TRC011-EN Answers Glossary Glossary Glossary Trane Company