packageExercise8TwoStageRefrigerationCycle
Extends from Modelica.Icons.ExamplesPackage (Icon for packages containing runnable examples).
Information
This package contains examples of a two stage vapor cycle. The examples differ by:
- The solution method: Inversion vs. pseudo inversion "controllers".
English problem description
A refrigeration system with two-stage compression operates as follows: The adiabatic lowPressureCompressor
draws dry saturated vapor (R134a) from the
evaporator at 1.00 bar and compresses it with an isentropic efficiency
of eta_is = 0.900 to 6.00 bar.
The superheated vapor at state 2 is fed to the intermediate pressure flashChamber.
Saturated vapor (state 5) is drawn from the flashChamber and compressed in the highPressureCompressor to 14.0 bar,
reaching a superheated temperature of 335 K.
After isobaric condensation and subsequent isobaric subcooling to T7 = 300 K in the
condenser, the refrigerant is expanded adiabatically in the highPressureValve
to the intermediate pressure and returned to the flashChamber.
Saturated liquid (state 3) is withdrawn from the flashChamber, throttled adiabatically in the lowPressureValve to
the evaporator pressure and completely evaporated in the evaporator, closing the loop.
The system is sized to cool 75.0 kg (specific heat capacity 2 kJ/(kg.K)) in 15 min by 40 K.
The mechanic efficiencies of the compressors are 0.95.
Contents
| Name | Description |
|---|---|
 Inversion | |
 PseudoInversion |