Patent ID: 9032747
Filing Date: 2015-05-19
Classification: F24F,F25B

Abstract:
1. An air-conditioning apparatus that includes a refrigerant cycle formed by connecting a compressor, a heat source side heat exchanger, a plurality of expansion devices, and a plurality of heat exchangers related to heat medium with refrigerant pipes, the refrigerant cycle circulating a refrigerant, and a heat medium cycle formed by connecting a plurality of pumps, a plurality of use side heat exchangers, and the heat exchangers related to heat medium, the heat medium cycle circulating a heat medium, wherein the air-conditioning apparatus is capable of carrying out: a heating only operation mode that heats the heat medium by allowing a high-temperature high-pressure refrigerant discharged from the compressor to flow through all of the heat exchangers related to heat medium; a cooling only operation mode that cools the heat medium by allowing a low-temperature low-pressure refrigerant to flow through all of the heat exchangers related to heat medium; and a cooling and heating mixed operation mode that heats the heat medium by allowing the high-temperature high-pressure refrigerant discharged from the compressor to flow through one or some of the heat exchangers related to heat medium, and cools the heat medium by allowing the low-temperature low-pressure refrigerant to flow through one or some of the remaining heat exchangers related to heat medium, the air-conditioning apparatus, comprising: a first refrigerant flow switching device that switches flow paths of the refrigerant in an outdoor unit; a refrigerant flow rectifying device that permits the refrigerant flowing in the refrigerant pipes between the outdoor unit and a heat medium relay unit to flow in a constant direction regardless of switching state of the first refrigerant switching device; a plurality of second refrigerant flow switching devices, which are provided for the heat exchangers related to heat medium respectively, each switching between a passage in which the refrigerant from the outdoor unit flows into the corresponding heat exchanger related to heat medium and a passage in which the refrigerant from the corresponding heat exchanger related to heat medium flows out to the outdoor unit; and a third refrigerant flow switching device that switches between a passage in which the refrigerant from the outdoor unit flows into the expansion devices and a passage in which the refrigerant from the outdoor unit flows into the second refrigerant flow switching devices, wherein a pressure in a passage in which the refrigerant from the outdoor unit flows into each of the second refrigerant flow switching devices is higher than a pressure in a passage in which the refrigerant flows therefrom out to the outdoor unit regardless of switching states of the first refrigerant flow switching device, the second refrigerant flow switching devices, and the third refrigerant flow switching device, and while the compressor is stopped, switching states of the second refrigerant flow switching devices are switched so as to be in the switching state thereof in the cooling and heating mixed operation mode.