Air-conditioning apparatus

摘要

An air-conditioning apparatus capable of storing a surplus of refrigerating machine oil and returning a necessary amount of the refrigerating machine oil to a compressor as required. In an air-conditioning apparatus, a controller determines the amount of refrigerating machine oil that is present in a compressor by measuring power of the compressor and controls opening and closing of a solenoid valve on the basis of the measurement results.

主权项

1. An air-conditioning apparatus comprising:
a compressor that compresses and discharges a refrigerant; a condenser that exchanges heat between a refrigerant that is discharged from the compressor and a heat medium; an expansion valve that depressurizes a refrigerant that has flowed out from the condenser; an evaporator that exchanges heat between a refrigerant that is depressurized by the expansion valve and a heat medium; an oil separator that is disposed on a discharge side of the compressor and that separates refrigerating machine oil from the refrigerant that is discharged by the compressor; an oil reservoir that is disposed on a downstream side of the oil separator and that stores refrigerating machine oil that is separated by the oil separator, a first connection pipe that connects a bottom portion of the oil reservoir and a suction side of the compressor; a second connection pipe that connects a portion of the oil reservoir that is more above than a portion thereof to which the first connection pipe is connected and the suction side of the compressor; a solenoid valve that is provided to the first connection pipe and that opens and closes the first connection pipe; and a controller that controls opening and closing of the solenoid valve on the basis of an amount of refrigerating machine oil that is present in the compressor, wherein the controller uses, for determining the amount of refrigerating machine oil that is present in the compressor, at least one of power of the compressor, a drive frequency of the compressor, and a quality of a refrigerant that is discharged from the compressor.