Abstract
Year-round cooling air conditioners can be driven efficiently by circulating the refrigerant not with the compressor but with the pump when the outside air temperature is lower than the room temperature in winter. But in this case, we have some problems such as the cavitation of the pump, because of the phase change of refrigerant. Therefore, in order to clarify the mechanism of the occurrence of the cavitation at pump inlet port, we construct the dynamic model and analysis the system in detail using it. The validity of the dynamic model is confirmed by experiment. As a result, it is cleared that the cavitation is caused because the refrigerant temperature reaches the equilibrium temperature to the refrigerant pressure late at pump inlet port, when the heat flow rate of the condenser increases.
