Patent ID: 9746223
Date: 2017-08-29
CPC Classifications: F25B

Claim:
1. An air-conditioning apparatus comprising: a refrigeration cycle device including a refrigerant circuit in which a compressor that sends a zeotropic refrigerant mixture containing tetrafluoropropene and R32, a refrigerant flow switching device for switching a passage through which the refrigerant circulates, a heat source side heat exchanger for exchanging heat of the refrigerant, a refrigerant expansion device for controlling pressure of the refrigerant, and a heat exchanger related to heat medium that is capable of exchanging heat between the refrigerant and a heat medium different from the refrigerant are connected by pipes, circulating the refrigerant, the refrigeration cycle device further including a circulating refrigerant composition detection circuit having a low-pressure side pressure detection device for detecting low-pressure side pressure corresponding to pressure of the refrigerant that is to be suctioned by the compressor, a high-low pressure bypass pipe connecting a pipe on a discharge side of the compressor and a pipe on a suction side of the compressor, a bypass expansion device disposed in the high-low pressure bypass pipe, a high-pressure side temperature detection device for detecting high-pressure side temperature corresponding to temperature of the refrigerant flowing into the bypass expansion device, a low-pressure side temperature detection device for detecting low-pressure side temperature corresponding to temperature of the refrigerant discharged from the bypass expansion device, and a heat exchanger related to refrigerant that exchanges heat between the refrigerant flowing into the bypass expansion device and the refrigerant discharged from the bypass expansion device; a heat medium side device including a heat medium circuit in which a heat medium sending device for circulating the heat medium to be used for the heat exchange performed by the heat exchanger related to heat medium, a use side heat exchanger that exchanges heat between the heat medium and air in a space to be conditioned, and a heat medium flow switching device that switches to pass the heat medium having flowed through the heat exchanger related to heat medium toward the use side heat exchanger are connected by pipes; a first controller that detects a circulation composition of the zeotropic refrigerant mixture in the refrigeration cycle device on the basis of at least the low-pressure side pressure, the high-pressure side temperature, and the low-pressure side temperature, and changes a driving frequency of the compressor based on, and in response to, a detected circulation composition data of the zeotropic refrigerant mixture that corresponds to circulation composition of the zeotropic refrigerant mixture; and a second controller disposed at a position away from the first controller and connecting to be capable of communicating to the first controller with wire or no wire, the second controller performing, in a heat medium relay unit including the heat exchanger related to heat medium, at least one of a calculation of evaporating temperature of the heat exchanger related to heat medium that functions as an evaporator and degree of superheat on a refrigerant outlet side of the heat exchanger related to heat medium that functions as an evaporator and a calculation of condensing temperature of the heat exchanger related to heat medium that functions as a condenser and degree of subcooling on the refrigerant outlet side of the heat exchanger related to heat medium that functions as a condenser, on the basis of the circulation composition received through the communication with the first controller, wherein at least the compressor, the refrigerant flow switching device, the heat source side heat exchanger, and the circulating refrigerant composition detection circuit are accommodated in an outdoor unit, at least the heat exchanger related to heat medium and the refrigerant expansion device are accommodated in the heat medium relay unit, the outdoor unit and the heat medium relay unit are provided separately and are installable at separate positions to be away from each other, the first controller is provided in or near the outdoor unit, the second controller is disposed in or near the heat medium relay unit, and the heat exchanger related to heat medium is one of a plurality of heat exchangers related to heat medium, including at least a first heat exchanger related to heat medium and a second heat exchanger related to heat medium; the air-conditioning apparatus further comprising: a first refrigerant temperature detection device, connected to an inlet end of the first heat exchanger related to heat medium, for detecting temperature on a refrigerant inlet side when the heat exchanger related to heat medium is functioning as a condenser; a second refrigerant temperature detection device, different from the first temperature detection device, and connected to an outlet end of the second heat exchanger related to heat medium, for detecting temperature on the refrigerant outlet side when the heat exchanger related to heat medium is functioning as a condenser; a first refrigerant pressure detection device connected to an outlet end of the first heat exchanger related to heat medium and to the first refrigerant temperature detection device, and disposed directly between the heat exchanger related to heat medium and the refrigerant flow switching device, for detecting pressure of the refrigerant flowing into the first heat exchanger related to heat medium; and a second refrigerant pressure detection device, different from the first refrigerant pressure detection device, and connected to an inlet end of the second heat exchanger related to heat medium, the inlet end of the second heat exchanger related to heat medium being opposite to the outlet end of the first heat exchanger related to heat medium to which the first refrigerant pressure detection device is connected, and to the second refrigerant temperature detection device, for detecting pressure of refrigerant discharged from the second heat exchanger related to heat medium when functioning as a condenser; wherein the second controller is configured to determine the pressure of the refrigerant discharged and entered from at least one of the plurality of heat exchangers related to heat medium irrespective of a current operational mode, as the first refrigerant pressure detection device and the second refrigerant pressure detection device are located on opposite sides of their respective heat exchangers, calculate the degree of superheat of the plurality of heat exchangers related to heat medium functioning as an evaporator on the basis of the detected circulation composition data of the zeotropic refrigerant mixture, the pressure detected by the first refrigerant pressure detection device, and the temperature detected by the first refrigerant temperature detection device, and calculate the degree of subcooling of the plurality of heat exchangers related to heat medium functioning as a condenser on the basis of the detected circulation composition data of the zeotropic refrigerant mixture, the pressure detected by the first refrigerant pressure detection device, and the temperature detected by the second refrigerant temperature detection device.