Exergy economy analysis and comparison of three kinds of refrigerating machines used in air conditioning systems

Using the exergy cost equation, establishes a model of exergy economy analysis for refrigerating machines. Combined with an air conditioning system of a hotel in Beijing area, compares the exergy economy among the vapor compression refrigerating machine, double-effect lithium-bromide absorption-type refrigerating machine and direct-fired lithium-bromide absorption-type refrigerating machine. The results show that the economy of lithium-bromide absorption-type refrigerating machine is better though it can not save energy. There being price factor, in current pricing structure, exergy cost of unit fuel power for coal is one-tenth that of electric power, which indicates that present energy price in China is irrational, especially the price of electric power is over high compared with that of coal.