Trane TRG-TRC011-EN manual Equilibrium Chart

Page 20

period one

Absorption Refrigeration Cycle

notes

15 psia

concentration

[103.4 kPa]

0

e

0

r

u

5

s

s

5 psia

5

re

p

5

r

o

[34.5 kPa]

p

a

0

v

1 psia

[6.9 kPa]

$

0.1 psia

&

%

[0.69 kPa]

50°F

100°F

150°F

200°F

LiBr solution

[10°C]

[37.8°C]

[65.6°C]

[93.3°C]

Figure 18

solution temperature

Equilibrium Chart

The performance of the absorption refrigeration cycle can be analyzed using a special chart called an Equilibrium Chart for Aqueous Lithium Bromide Solutions. This chart plots the vapor pressure (vertical axis) versus the temperature (horizontal axis) and concentration (diagonal lines) of the lithium bromide (LiBr) solution.

The chart shows that an increase in concentration ($ to %), at a constant solution temperature, results in a decrease in vapor pressure. Conversely, a decrease in solution temperature ($ to &), at a constant concentration, results in a decrease in vapor pressure. Assuming that no air or other noncondensables are inside the chiller, the vapor pressure of the solution determines the temperature at which the refrigerant will vaporize. In other words, the combination of solution temperature and concentration determines the temperature at which the refrigerant will boil (vaporize).

TRG-TRC011-EN

15

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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