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: Operation data of a refrigerant circuit is acquired after an initial refrigerant charge amount of refrigerant is charged in the refrigerant circuit and operation of the refrigerant circuit is started, an internal volume of a high-pressure pipe 6 is computed from the obtained operation data and the initial refrigerant charge amount input in a input unit 112, a target refrigerant charge amount is computed from the computed internal volume of the high-pressure pipe 6 and a standard operating state acquired in advance, the standard operating state being operation data of the refrigerant circuit when the refrigerant circuit is in a standard operating state that satisfies a preset condition, and an additional refrigerant charge amount is computed from the target refrigerant charge amount and the initial refrigerant charge amount.

Abstract: Provided is a first unit including a first unit including a compressor and a first heat exchanger; a plurality of second units each including a second heat exchanger and each being connected to the first unit via a plurality of branched pipes; a plurality of valves configured to open to permit refrigerant flows and close to not permit the refrigerant flows; a storage unit configured to store connection information indicating a relationship of connection between the plurality of second units and the plurality of pipes; a closed path pipe that is any of the plurality of branched pipes to which no second unit is connected, and a control unit configured to detect whether the closed path pipe is included in the connection information.

Abstract: The air-conditioning apparatus includes a compressor; a heat source side heat exchanger; a use side pressure-reducing mechanism; a use side heat exchanger and an accumulator connected by a pipe so that a refrigerant circulates therethrough; a high-low pressure bypass pipe; a high-low pressure bypass unit installed in the high-low pressure bypass pipe; and a unit controller configured to perform a refrigerant amount detection operation in which an operation frequency of the compressor is controlled so that a value of an evaporating temperature becomes an evaporating temperature target value of the compressor to discharge a liquid-state refrigerant of the refrigerant from the accumulator, and control an opening degree of the high-low pressure bypass unit in performing the refrigerant amount detection operation.

Abstract: An air conditioning system includes: first and second utilization side heat exchangers and a heat source side heat exchanger respectively connected in series; a compressor connected between the first utilization side heat exchanger and the heat source side heat exchanger; an expansion valve connected between the first utilization side heat exchanger and the second utilization side heat exchanger; a pressure control device connected between the second utilization side heat exchanger and the heat source side heat exchanger; and a bypass valve connected between the expansion valve and the heat source side heat exchanger. The bypass valve provides a variable amount of liquid refrigerant flowing from the expansion valve to the heat source side heat exchanger. The pressure control device and the bypass valve cooperate with each other to keep a temperature of the compressor below a maximum allowable temperature predetermined for the compressor.

Abstract: An air-conditioning apparatus has different two modes including a response detection diagnosis in which a control unit diagnoses a trouble of a component device during the trouble diagnosis operation based on presence or absence of a response from the operational state sensor when the mode has forcibly changed the device operation, and a performance detection diagnosis in which a trouble is detected by a detection value of the operational state sensor at a time when the operational state of the trouble diagnosis operation is stable, and the performance detection diagnosis is executed after the response detection diagnosis is executed.

Abstract: Operation data of a refrigerant circuit is acquired after an initial refrigerant charge amount of refrigerant is charged in the refrigerant circuit and operation of the refrigerant circuit is started, an internal volume of a high-pressure pipe 6 is computed from the obtained operation data and the initial refrigerant charge amount input in a input unit 112, a target refrigerant charge amount is computed from the computed internal volume of the high-pressure pipe 6 and a standard operating state acquired in advance, the standard operating state being operation data of the refrigerant circuit when the refrigerant circuit is in a standard operating state that satisfies a preset condition, and an additional refrigerant charge amount is computed from the target refrigerant charge amount and the initial refrigerant charge amount.

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: An air conditioning apparatus includes a plurality of heat source apparatuses having heat source apparatus side heat exchangers and compressors, one or a plurality of indoor units having flow rate control devices and indoor unit side heat exchangers, at least two main pipes for performing connection-piping between a plurality of heat source apparatuses and one or a plurality of indoor units, a tubular distributor for branching the refrigerant from the main pipe flowing from the inlet to a plurality of outlets to distribute into a plurality of heat source apparatuses, and connection piping for connecting the plurality of heat source apparatuses and distributor respectively. Among a plurality of heat source apparatuses, the distributor is fixedly disposed at a specified position and in a specified direction against one heat source apparatus.

Abstract: To provide an air-conditioning apparatus that can prevent the formation of frost on indoor-side heat exchangers functioning as an evaporator even when the outside air temperature is low, and can use unmodified normal indoor units even when a portion of the indoor units is used in a place that has a large sensible heat load. An air-conditioning apparatus capable of simultaneous heating and cooling operation includes a heat source unit, a plurality of indoor units, and a relay unit that connects the heat source unit to the indoor units. A flow control unit that controls a flow amount of a refrigerant that flows through the indoor units that are in cooling operation is provided to a piping on the downstream side of a merging section of a piping through which flows the refrigerant that flows out from the indoor units that are in cooling operation.

Abstract: To obtain an air conditioner which ensures safe operation and protection of the device and can carry out an operation with favorable energy efficiency by efficiently compressing the refrigerant. The air conditioner 100 is capable of performing a cooling/heating mixed operation, constituting a refrigerant circuit by piping connection of a heat-source side unit 10 having a heat-source side heat exchanger 15 and a compressor 11, a plurality of load-side units 50 having a load-side throttle device 51 and a load-side heat exchanger 52, and a cooling/heating branch unit 30 having a gas/liquid separator 31.

Abstract: An air conditioning apparatus includes a plurality of heat source apparatuses having heat source apparatus side heat exchangers and compressors, one or a plurality of indoor units having flow rate control devices and indoor unit side heat exchangers, at least two main pipes for performing connection-piping between a plurality of heat source apparatuses and one or a plurality of indoor units, a tubular distributor for branching the refrigerant from the main pipe flowing from the inlet to a plurality of outlets to distribute into a plurality of heat source apparatuses, and connection piping for connecting the plurality of heat source apparatuses and distributor respectively. Among a plurality of heat source apparatuses, the distributor is fixedly disposed at a specified position and in a specified direction against one heat source apparatus.