Patent ID: 9003819
Filing Date: 2015-04-14
Classification: F24D,F25B,Y02B

Abstract:
1. A heat pump apparatus comprising: a refrigerant circuit which includes a compressor, a utilization-side heat exchanger, a first expansion valve, and an outdoor heat exchanger; an injection pipe which includes a solenoid switching valve and a second expansion valve; and an objective supercooling degree table which stores objective supercooling degrees which are determined by condensing pressure in the refrigerant circuit, whether the condensing pressure is rising or dropping from a predetermined threshold value of condensing pressure, and rotation number of the compressor, wherein liquid refrigerant is injected to the compressor by way of the injection pipe, wherein the heat pump apparatus switches between a first case where the liquid refrigerant is injected to the compressor and a second case where the liquid refrigerant is not injected, wherein, in the second case, the first expansion valve is controlled to be opened or closed so that an operation of the heat pump apparatus is continued at the objective supercooling degree which is extracted from the objective supercooling degree table, and wherein, in the first case, the objective supercooling degree is extracted from the objective supercooling degree table and corrected by a determined value, and the first expansion valve is controlled so that the operation of the heat pump apparatus is continued at the corrected supercooling degree.