Refrigeration Cycle: Screencast
Explains each step in a refrigeration cycle and the energy balance for each step. The process is shown in a pressure-enthalpy diagram.
We suggest you list the important points in this screencast as a way to increase retention.
Important Equations:
Coefficient of performance: \[COP = \frac{Q_C}{W_S}\,\,\,(COP > 1)\] where \(Q_C\) is the heat added to the evaporator (low temperature part of the cycle) and \(W_S\) is the work done by the compressor \(Q_C > 0, W_S>0)\)
Energy balance for adiabatic compressor: \[\Delta H = W_S\] where \(\Delta H\) is the enthalpy change across the compressor \((\Delta H > 0)\)
Entropy (\(S\)) change for reversible adiabatic compressor: \[\Delta S = 0\] Energy balance for evaporator: \[\Delta H = Q_C\] where \(\Delta H\) is the enthalpy change across the evaporator and \(Q_C\) is the heat added at low temperature \((Q_C > 0)\)
Energy balance for condenser: \[\Delta H = Q_H\] where \(\Delta H\) is the enthalpy change across the condenser and \(Q_H\) is the heat removed at high temperature \(Q_H < 0\)
Energy balance for adiabatic throttle: \[\Delta H = 0\] (no heat transfer and no work on throttle)