抄録
This paper describes numerical simulation of heat-pump cycle, which predicts how a heat-pump system behaves in a variety of conditions and specifications. A model of heat-pump system was consisted of a constant rotational speed compressor, a condenser, an evaporator, a decompression device and connecting tubes. Steady state governing equations for refrigerant flows and the state of refrigerant given by REFPROP 8.0 were solved by iterations. Comparison with the experimental data of a small heat-pump system proved that the simulation sufficiently predicted the cycle and performances. Simulation of cycles and characteristics of a heat-pump system with less heat transfer coefficients of condenser caused by degradation and retrofit by installing an additional condenser revealed that the retrofit recovered performances of a degraded heat-pump system.