Abstract: An air-conditioning apparatus includes: a compressor allowing refrigerant injection thereto and compress and discharge the refrigerant at a high temperature; an indoor heat exchanger exchanging heat between air and refrigerant; a first flow rate control device adjusting and controlling a flow rate of refrigerant; and a plurality of outdoor heat exchangers being in parallel to exchange heat between outside air and refrigerant, a first defrosting pipe allowing a branched part of the refrigerant discharged from the compressor to pass and flow into the outdoor heat exchanger to be defrosted; a reducing device adjusting a pressure of refrigerant passing through the first defrosting pipe to a medium pressure; a second defrosting pipe from which the refrigerant having passed through the outdoor heat exchanger to be defrosted is injected into the compressor; and a reducing device adjusting a pressure of refrigerant passing through the second defrosting pipe to an injection pressure.

Abstract: An air-conditioning apparatus including a refrigerant circuit having an excess refrigerant recovery pipe connected between an inlet of at least one of heat source side heat exchangers and a first refrigerant flow blocking device or between an outlet of the at least one of the heat source side heat exchangers and a second refrigerant flow blocking device, to a passage connected to a suction side of a compressor, and an excess refrigerant recovery device disposed in the excess refrigerant recovery pipe.

Abstract: An air-conditioning apparatus including an outdoor unit having a compressor for compressing a refrigerant and a heat source side heat exchange for exchanging heat between the refrigerant and air, a plurality of indoor units having use side heat exchangers for exchanging heat between a heat transfer medium that flows therein and air, and relay unit disposed between the outdoor unit and the indoor units. The relay unit exchanges heat between the refrigerant conveyed from the outdoor unit and the heat transfer medium flowing in the indoor units. The relay unit includes a main relay unit that is connected to the outdoor unit with two pipes and a sub relay unit that is connect to the main relay unit with three pipes.

Abstract: To reduce pressure loss of refrigerant while suppressing a cost increase. [Solution] In an air-conditioning apparatus 100 having a compressor 201, a radiator 204 (301), an expansion device 302, and an evaporator 301 (204), which are connected by a refrigerant pipe to form a refrigeration cycle, at least a part of the refrigerant pipe (207, 208, 209, 210, 211, 212) that connects from the suction side of the compressor 201 to the evaporator 301 (204) is configured by a plurality of pipes connected in parallel, and a refrigerant that flows through the refrigeration cycle is a tetrafluoropropene-based refrigerant or a refrigerant mixture having tetrafluoropropene as a main component.

Abstract: A first bypass pipe has one end connected to a main pipe extending from a compressor to an indoor heat exchanger, and its other end branched off into parts that are each connected to the main pipe on an inlet side of an outdoor heat exchanger, and a second bypass pipe has one end connected to an injection port communicating with the compression chamber of the compressor in which compression is taking place and its other end branched off into parts that are each connected to the main pipe on an outlet side of the outdoor heat exchangers. During a defrosting operation that removes frost on the outdoor heat exchangers, a part of the refrigerant discharged from the compressor is supplied from the first bypass pipe to the outdoor heat exchanger to be defrosted, and is then passed through the second bypass pipe and injected from the injection port of the compressor.

Abstract: A refrigeration cycle is configured by connecting a compressor that compresses the refrigerant, a four-way valve that switches the circulation path of the refrigerant, a heat source side heat exchanger that exchanges heat, expansion valves that adjust the pressure of the refrigerant, and two or more intermediate heat exchangers that exchange heat between the refrigerant and the heat medium to heat and cool the heat medium, by piping. A heat medium circulation circuit is configured by connecting two or more intermediate heat exchangers, pumps that pressurize the heat medium, two or more use side heat exchangers that exchange heat between the heat medium and the air in the indoor space, and flow path switching valves that switch paths of the heated heat medium or the cooled heat medium to the use side heat exchangers, by piping.

Abstract: A multi-chamber air conditioner including a heat-source side refrigerant circuit in which a compressor, an outdoor heat exchanger, a first heat exchanger, a refrigerant flow-rate controller, and a second heat exchanger are connected in series, a first use-side refrigerant circuit in which the first heat exchanger and an indoor heat exchanger are connected in series, and a second use-side refrigerant circuit in which the second heat exchanger and the indoor heat exchanger are connected in series, and a heat-source side refrigerant circulating in the heat-source side refrigerant circuit and a use-side refrigerant circulating in the use-side refrigerant circuit are heat-exchanged in the first heat exchanger. The heat-source side refrigerant circulating in the heat-source side refrigerant circuit and the use-side refrigerant circulating in the use-side refrigerant circuit are heat-exchanged in the second heat exchanger.

Abstract: An air-conditioning apparatus includes a refrigerant circuit formed by connecting, with pipes, a compressor to compress refrigerant and discharge the compressed refrigerant, a first heat exchanger, a subcooling heat exchanger exchanges heat between a portion of the refrigerant flowing in a first flow passage and another portion of the refrigerant flowing in a second flow passage to subcool the portion of refrigerant flowing in the first flow passage, a first expansion device to decompress the refrigerant, a second heat exchanger, and an accumulator connected to a suction side of the compressor and configured to store excess refrigerant, so that the refrigerant is circulated through the refrigerant circuit. The air-conditioning apparatus is configured to prevent the discharge temperature of the compressor from being excessively increased irrespective of the operation mode and therefore prevent damage to the compressor.

Abstract: An air-conditioning apparatus includes a refrigerant circuit formed by connecting pipes, a compressor including a compression chamber and an injection port through which refrigerant is introduced into the compression chamber, a first heat exchanger, a subcooling heat exchanger that includes a first flow passage and a second flow passage and exchanges heat between refrigerant flowing in the first flow passage and refrigerant flowing in the second flow passage to subcool the refrigerant flowing in the first flow passage, a first expansion device, a second heat exchanger, and an accumulator In addition, a first bypass pipe connects the second flow passage of the subcooling heat exchanger with a segment of the pipes, positioned on a refrigerant inflow side of the accumulator; an expansion device to adjust a flow rate of the refrigerant flowing in the first bypass pipe; a second bypass pipe that connects a segment of the pipes with the injection port, the segment being positioned between the first heat exchanger a

Abstract: A controller, at least during the heating operation, controls the opening degree of a second expansion device and/or a third expansion device based on a discharge refrigerant temperature detected by a discharge refrigerant temperature detector, or a value computed using the discharge refrigerant temperature, and causes refrigerant having a quality equal to or greater than 0.9 and less than or equal to 0.99 to be suctioned into a compressor.

Abstract: A refrigeration cycle device 100 where a combustible refrigerant circulates includes a bypass pipe 5 that is connected so that part of the refrigerant that flows through a circulation pipe extending from a condenser 2 to a flow control valve 3 bypasses the flow control valve 3 and an evaporator 4; a bypass flow control valve 6 that controls the amount of the refrigerant flowing through the bypass pipe 5; a heat exchanger 7 that allows heat exchange between the refrigerant that flows through the bypass pipe 5 after flowing out of the bypass flow control valve 6 and the refrigerant that flows through the circulation pipe after flowing out of the condenser 2; and a subcooling degree sensor T73 that detects the subcooling degree of the refrigerant at the inlet of the flow control valve 3.

Abstract: An air-conditioning apparatus divides an outdoor heat exchanger to form parallel heat exchangers and supplies part of refrigerant from a compressor to the parallel heat exchangers alternately to perform defrosting, performs medium-pressure defrosting in which part of the refrigerant from the compressor is decompressed and supplied to a parallel heat exchanger to be subjected to defrosting, and the refrigerant after being used for defrosting is injected into the compressor. A first flow switching unit performs switching of a connection mode of ends of the parallel heat exchangers on compressor side, where the pressure changes among high pressure, medium pressure, and low pressure according to operation contents, to one of three modes: a mode with the ends connected to the compressor discharge side, a mode with the ends connected to the compressor suction side, and a mode with the ends connected to neither the discharge nor suction side.

Abstract: An air-conditioning apparatus includes a main circuit in which a compressor, an indoor heat exchanger, a first flow control device, and a plurality of parallel heat exchangers connected in parallel to each other are sequentially connected via a pipe to allow refrigerant to circulate, a first defrost pipe that branches a part of the refrigerant discharged from the compressor and allows the refrigerant to flow into the parallel heat exchanger to be defrosted among the plurality of parallel heat exchangers, a expansion device provided in the first defrost pipe and configured to depressurize the refrigerant discharged from the compressor, and a connection switching device that allows the refrigerant flowing out of the parallel heat exchanger to be defrosted to flow into the main circuit at a position upstream of the parallel heat exchangers other than the parallel heat exchanger subject to defrosting.

Abstract: A controller performs medium pressure control that controls the opening degree of a second expansion device based on a deviation between a target value of medium pressure, and a detection result of a medium pressure detector or a predicted value. The controller controls the opening degree of a third expansion device based on a target value of a discharge refrigerant temperature of a compressor or a target value related to the discharge refrigerant temperature, and a detection result of a discharge refrigerant temperature detector or a value related to the discharge refrigerant temperature computed using a detected detection result, and regulates a flow rate of refrigerant to supply to a suction side of the compressor via an injection pipe.

Abstract: A refrigeration cycle apparatus including a heat source side heat exchanger including a first heat exchanger and a second heat exchanger connected in parallel; an air-sending device that supplies air, which is an object to be heat exchanged in the first heat exchanger and the second heat exchanger, in a variable manner; solenoid valves that each opens and closes a refrigerant passage of the first heat exchanger and the second heat exchanger; a third refrigerant circuit that is parallelly connected to the first heat exchanger and the second heat exchanger; and a flow control valve that controls the flow rate of the refrigerant flowing in the third refrigerant circuit. The refrigeration cycle apparatus can improve continuity of control of a heat exchange capacity of a heat source side heat exchanger.

Abstract: An air-conditioning apparatus includes an outdoor unit including a compressor configured to compress a first-side refrigerant and a heat-source-side heat exchanger configured to cause heat exchange between air and the first-side refrigerant, plural indoor units including indoor heat exchangers configured to cause heat exchange between the air and a second-side refrigerant, plural intermediate heat exchangers configured to cause heat exchange between the first-side and second-side refrigerants and connected to the outdoor unit by a first-side refrigerant pipe and connected to the indoor units by a second-side refrigerant pipe, and a flow switching device configured to switch combination of connection between the indoor units and the intermediate heat exchangers. The indoor units include convective indoor units and radiant indoor units, the convective indoor units include a convective indoor heat exchanger, and the radiant indoor units include a radiant indoor heat exchanger.

Abstract: A valve block and a valve block unit which allow simplification and miniaturization of a pipe arrangement. The valve block includes at least one flow switching valve including a valve body, the valve selectively switching between conductions of a fluid (heat medium), a first pipe (heating outward-flow main pipe) and a second pipe (cooling outward-flow main pipe), switched by the flow switching valve, allowing the fluid to be conveyed therethrough, and a third pipe (first branch pipe) that selectively communicates with the first pipe or the second pipe, the flow switching valve, the first pipe, the second pipe, and the third pipe being connected to each other.

Abstract: To provide an air-conditioning apparatus capable of achieving energy saving. An air-conditioning apparatus controls first heat medium flow switching devices and second heat medium flow switching devices in a heating only operation mode and a cooling only operation mode such that a flow rate through which a heat medium circulates is formed between all of the heat exchangers related to heat medium and at least one of use side heat exchangers.

Abstract: A refrigerating air-conditioning apparatus, at least provided with no possibility that a foreign material returns to a compressor from an accumulator at a time of the pipeline-cleaning operation firstly, and provided with a possibility to perform a collecting operation for the foreign material in a short time secondary, is provided. The heat-source side unit includes an accumulator provided with a function to separate and collect the foreign material in an existing pipeline, a collecting container for collecting the foreign material separated by the accumulator, and an oil return pipeline for returning refrigerating machine oil to the compressor via a flow amount adjusting device, installed at a lower portion of the accumulator, and at a time of ordinary cooling or heating operation, the refrigerating machine oil is caused to flow into the oil return pipeline, and at a time of pipeline cleaning and foreign material-collecting operations, the flow amount adjusting device is fully closed.

Abstract: An air-conditioning apparatus includes an outdoor-side flow rate control device (a fourth flow rate control device) that generates an intermediate pressure for injection into a compressor, and a bypass flow rate control device (a sixth flow rate control device) that is placed at a bypass pipe allowing bypassing of an outdoor heat exchanger in parallel to the outdoor-side flow rate control device and that controls the amount of heat exchange of the outdoor heat exchanger together with the outdoor-side flow rate control device.