Trane TRG-TRC011-EN manual High affinity for water refrigerant

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period one

Absorption Refrigeration Cycle

notes

▲

◆High affinity for water (refrigerant)

◆In solution, higher boiling point than water

◆Nontoxic

Figure 8

Additionally, the absorption refrigerant cycle uses a second fluid called an absorbent solution. The absorbent solution is confined to the absorber and generator sections of the cycle, and is used to carry the refrigerant from the low-pressure side (evaporator) to the high-pressure side (condenser) of the chiller. For this purpose, the absorbent should have a strong affinity (attraction) for the refrigerant and, when in solution with the refrigerant, a boiling point that is substantially higher than that of the refrigerant.

The absorbent commonly used with water (the refrigerant) is lithium bromide. Lithium bromide, a nontoxic salt, has a high affinity for water. Also, when in solution with water, the boiling point of lithium bromide is substantially higher than that of water. This makes it easy to separate the refrigerant from the absorbent at low pressures. A certain quantity of absorbent solution, therefore, is pumped from the absorber to the generator in order to transport the refrigerant.

Another common refrigerant–absorbent pair is ammonia as the refrigerant and water as the absorbent. These fluids are more common in small residential applications. There are other refrigerant–absorbent combinations; this clinic, however, will focus on water as the refrigerant and lithium bromide as the absorbent.

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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
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