An air conditioner includes: an outdoor unit; a liquid-refrigerant connection pipe and a gas-refrigerant connection pipe; an indoor unit; a gas-side shutoff valve; a refrigerant sensor; and a controller. The indoor unit is connected to the outdoor unit via the liquid-refrigerant and gas-refrigerant connection pipes, is arranged in an air-conditioning target space, and includes: an indoor heat exchanger that performs heat exchange between a refrigerant circulated between the indoor unit and the outdoor unit via the liquid-refrigerant and gas-refrigerant connection pipes and air sent to the air-conditioning target space; an indoor expansion valve that decompresses the refrigerant; a heat-exchange-side indoor liquid-refrigerant pipe that connects a liquid side of the indoor heat exchanger to the indoor expansion valve; and a connection-side indoor liquid-refrigerant pipe that connects the indoor expansion valve to the liquid-refrigerant connection pipe.

The refrigeration cycle apparatus includes a refrigerant circuit, a controller to control the refrigerant circuit, a bypass flow path, and a flow control valve. The bypass flow path communicates between the discharge side of the compressor and the first outdoor heat exchanger or between the discharge side of the compressor and the second outdoor heat exchanger. The flow control valve is provided to the bypass flow path. The refrigerant circuit is configured to be able to perform a heating defrosting simultaneous operation. The heating defrosting simultaneous operation is an operation of supplying part of the refrigerant discharged from the compressor to one of the first outdoor heat exchanger and the second outdoor heat exchanger via the bypass flow path, causing the other of the first outdoor heat exchanger and the second outdoor heat exchanger to serve as an evaporator, and causing the indoor heat exchanger to serve as a condenser.

A heat pump air conditioning system and a control method. The heat pump air conditioning system includes: a compressor; an indoor unit heat exchanger, an outdoor unit heat exchanger and a throttling device; a refrigerant circulation loop, connecting the compressor, the indoor unit heat exchanger, the outdoor unit heat exchanger and the throttling device in series; the heat storage module, disposed in the refrigerant circulation loop and configured to absorb heat from refrigerant in the refrigerant circulation loop and store heat when heat storage is required, and to heat the refrigerant in the refrigerant circulation loop when the outdoor unit heat exchanger defrosting is required. The heat pump air conditioning system can store excess heat of the system for defrosting when indoor heat load is low, and release heat for defrosting by means of the heat storage module during a defrosting process while continuing supplying heat to a room.

A refrigeration cycle apparatus capable of performing pump down operation while suppressing degradation in performance is provided. The refrigeration cycle apparatus includes an outdoor heat exchanger, a compressor including an inlet side and an outlet side, at least one indoor heat exchanger, a four-way valve, a check valve including an inlet side and an outlet side, a pipe serving as a first flow path connecting the outlet side of the check valve to the inlet side of the compressor, a first on-off valve, and a refrigerant leak detection device. The refrigeration cycle apparatus is configured such that, when a refrigerant leak is detected by the refrigerant leak detection device, pump down operation is performed as refrigerant transfer operation of transferring the refrigerant from the indoor heat exchanger to the outdoor heat exchanger.

A heat pump system includes a compressor, usage side heat exchanger, heat source side heat exchanger, expansion mechanism, main refrigerant flow control device switchable between cooling and heating modes, gas reheat heat exchanger connected in the refrigerant circuit, a fan disposed to direct an airflow across the usage side heat exchanger and the gas reheat heat exchanger into a target space, and a secondary refrigerant flow control device switchable between first and second modes. Refrigerant flows from the discharge line to the main refrigerant flow control device in the heating mode and the cooling mode in the first mode. Refrigerant flows from the discharge line to the gas reheat heat exchanger in a gas reheat mode and then flows to the main refrigerant flow control device in the second mode. A flow of the heat transfer medium to the heat source side heat exchanger is adjustable.

An accumulator assembly and a heat pump system. The accumulator assembly comprises: an accumulator tank body, wherein an inlet and outlet port is disposed at the bottom of the tank body and is flush therewith; and a connecting pipe, having a first end connected to the inlet and outlet port, and a second end for connection to an air conditioning system. According to the accumulator assembly of the present invention, because the inlet and outlet port is flush with the bottom of the accumulator tank body, in the case in where all the refrigerant is needed for the operation of the system, refrigerant and lubricating oil accumulated within the accumulator tank body can be completely drained from the tank body, thus ensuring sufficient refrigerant to satisfy load demand while simultaneously ensuring sufficient lubricating oil to satisfy the lubrication requirements of the compressor.

Provided is a system for air-conditioning and hot-water supply configured to selectively perform cooling and heating operations, comprising: an outdoor unit having a compressor and an outdoor heat exchanger; at least one or more indoor units each of which is connected to the outdoor unit and includes an indoor heat exchanger; a hot-water supply unit connected to the outdoor unit so as to be arranged in parallel to the indoor unit and including a refrigerant-water heat exchanger; a controller configured to monitor for a request for hot-water supply from the hot-water supply unit while a cooling operation is being performed in at least one of the indoor units, and then to start the heating operation in accordance with the request; wherein the controller transmits to all of the indoor units, which are turned on for said cooling operation, a fan-stop command to stop a fan arranged at each indoor unit.

An air-conditioning apparatus includes a refrigerant circuit in which an outdoor unit, at least one load-side expansion device, and at least one load-side heat exchanger are connected by pipes to allow refrigerant to circulate. The outdoor unit includes a compressor including an injection port allowing the refrigerant to flow into a suction chamber, a heat-source-side heat exchanger for heat exchange for the refrigerant, and an accumulator. The load-side heat exchanger transfers heat between a load and the refrigerant. The outdoor unit includes: an injection pipe having one end connected between the heat-source-side heat exchanger and the load-side expansion device, and the other end connected to the injection port, in the refrigerant circuit; an outdoor-side expansion device located downstream from the one end of the injection pipe in the flow of the refrigerant from the load-side expansion device to the heat-source-side heat exchanger; and an injection expansion device that adjusts the amount of the refrigerant flowing through the injection pipe. Also, a controller is provided to control the opening degrees of the outdoor-side expansion device and the injection expansion device.

There is provided a HVAC system comprising: a fluid circuit for conveying a refrigerant; a compressor for compressing the refrigerant; three heat exchangers defining an evaporator, an outdoor exchanger and a heat recovery exchanger provided along the fluid circuit; an expansion valve provided along the fluid circuit; and a receiver connected in parallel to the expansion valve, wherein a fill valve is located between the receiver and a connection upstream of the expansion valve and a drain valve is located between the receiver and a connection downstream of the expansion valve; wherein the fluid circuit comprises a plurality of valves which are configured to be controlled based on a selected operating mode such that at least one of the outdoor exchanger and the heat recovery exchanger is connected to a discharge line of the compressor and in series with one of the other heat exchangers which is connected to a suction line of the compressor, with the expansion valve disposed between the heat exchangers; wherein the fill and drain valves are configured to be controlled to store a volume of refrigerant in the receiver so as to provide an effective refrigerant charge in the fluid circuit that corresponds to the selected operating mode.

A heating and cooling system includes a reversing valve configured to adjust a flow of refrigerant through the heating and cooling system, where the reversing valve includes a first configuration to flow the refrigerant through a first circuit of the heating and cooling system and a second configuration to flow the refrigerant through a second circuit of the heating and cooling system. The heating and cooling system also includes a controller configured to determine an operating parameter of a compressor of the heating and cooling system, where the controller is configured to adjust operation of the compressor based on the operating parameter to adjust a position of the reversing valve.