ABSTRACT
In a power cycle, heat is provided to produce mechanical energy. A refrigeration cycle operates in reverse: it receives mechanical energy which is used to raise the temperature level of heat.
In this chapter, we will transpose analyses on improving power cycles to refrigeration cycles, the optimization of which also calls for the reduction of irreversibilities.
Three types of refrigeration cycles are commonly used:
Refrigeration cycles;
Heat pump cycles;
Mechanical vapor compression cycles (Chapter 17).
The first two, which will be presented in this chapter, differ only by the levels of operating temperature and the desired effect. In refrigeration cycles, we try to cool a cold chamber, while a heat pump is used for heating. They put into play refrigeration fluids of various compositions, which allow one to transfer heat at low temperature to a medium at high temperature.
We analyze the main thermodynamic cycles which are generally used, including ejector cycles. A specific section is devoted to cryogenic cycles, in particular Linde and Claude.
