Single TXV

This model switches the operation of an air conditioner and a heat pump by switching the flow path of the refrigerant with a four-way valve, thereby reversing the flow of the refrigerant in the direction other than the compressor. The heat transfer coefficient of the refrigerant side in the heat exchanger is calculated at a constant value to accommodate both the evaporator and the condenser.

(In general, in air-refrigerant heat exchange, the heat transfer rate of the refrigerant side is so large compared to the heat transfer rate of the air side that the heat transfer rate of the air side is the rate-limiting factor for heat transfer and the effect of the refrigerant side heat transfer rate change on the heat exchanger performance is small.)

The simulation starts in air conditioner mode, and after startHeatCycle seconds, the four-way valve switches to the heat pump cycle.