ABSTRACT
This chapter first presents the basic thermodynamic parameters of real subcritical mechanical vapor compression geothermal heat pump, and most used diagrams and refrigerants. Second, the thermodynamic cycles of typical brine-to-air geothermal heat pumps with vertical closed-loop (indirect, secondary fluid) ground-coupled heat exchangers operating in heating and cooling modes, are described. Finally, some means to express the energy and exergy efficiencies of geothermal heat pumps are detailed.
