A heat pump system and a control method thereof. The heat pump system includes a compressor; a heat storage heat exchanger, the pipeline connection of which is configured to be disconnectable from the heat pump system; an indoor heat exchanger and an outdoor heat exchanger; a plurality of throttling elements; and a first type four-way valve and a second type four-way valve, the ports of which are respectively connected to the air inlet and the air outlet of the compressor; the unconnected ports of the first type four-way valve are respectively connected to the outdoor heat exchanger and the heat storage heat exchanger; and the unconnected ports of the second type four-way valve are respectively connected to the indoor heat exchanger and connected to the port connected to the air inlet through a capillary or on-off valve; in a combined defrosting mode, the refrigerant dissipates heat from the indoor heat exchanger and the outdoor heat exchanger respectively.

A heat exchanger includes an inner tube extending along a central axis, an array of a plurality of heat transfer members mounted to the inner tube, and a plurality of outer tubes disposed radially outward of and in parallel relationship to the inner tube, the inner and outer tubes extending longitudinally to pass through the array of heat transfer members. The heat exchanger is particularly suited for use as an engine exhaust cooler in connection with a transport refrigeration unit, wherein the inner tube defines an internal flow passage through which engine exhaust gas passes, each outer tube defines an internal flow passage through which refrigerant passes, and the plurality of flow passages between adjacent heat transfer members defines an air flow passage. In an embodiment, the heat transfer members may be annular disks having an internal chamber filled with air or other heat transfer working fluid.

An outdoor unit for a heat pump includes a refrigerant circuit, the outdoor unit including a compressor, a discharge pipe of the refrigerant circuit connected to a discharge side of the compressor, a bottom plate, the bottom plate having a base and an outer flange protruding upward from an outer edge of the base, a heat source heat exchanger supported on the bottom plate, a liquid refrigerant pipe of the refrigerant circuit connected to the heat source heat exchanger, and a defrosting bypass pipe connected at one end to the discharge pipe and at the opposite end to the liquid refrigerant pipe, the defrosting bypass pipe being arranged between an inner side of the flange and an outer side of the heat source heat exchanger.

During a normal operation, a refrigeration cycle device is switched to a refrigerant circuit in which heat contained in a high-pressure refrigerant flowing out of an interior radiator is stored in a heat storage member. When frost is formed on an evaporator, the refrigeration cycle device is switched to another refrigerant circuit in which the exterior heat exchanger is heated and defrosted using heat stored in the heat storage member as a heat source. The heat storage member uses a material formed by adding W (tungsten) as an additive to VO.sub.2 (vanadium dioxide) which is a transition metal oxide having a property of a phase transition between a metal and an insulator. The heat storage member effectively stores or dissipates heat depending on a temperature zone of the refrigerant, thereby suppressing an increase in energy consumption of a compressor.

Provided is an air-conditioning apparatus including a switching valve and a bypass circuit. The switching valve is provided between an expansion valve and an outdoor heat exchanger. The bypass circuit has a first end connected to a refrigerant pipe connecting a compressor and an indoor heat exchanger to each other, and a second end connected to the switching valve. During a heating operation, the air-conditioning apparatus causes a rotating member of the switching valve to rotate to sequentially connect, to the bypass circuit, flow passages of the outdoor heat exchanger connected in parallel, to thereby defrost the outdoor heat exchanger while performing the heating operation.

Disclosed are a method and device for controlling an air conditioner. The air conditioner includes an outdoor heat exchanger, an indoor heat exchanger, a heat storage heat exchanger, a compressor, a four-way valve assembly, and a throttling assembly, wherein the outdoor heat exchanger is connected to the indoor heat exchanger by means of a first pipeline and a bypass, the outdoor heat exchanger is connected to the compressor by means of a second pipeline, the indoor heat exchanger is connected to the compressor by means of a third pipeline, the heat storage heat exchanger is arranged on the bypass, the throttling assembly is arranged on the bypass, the four-way valve assembly includes a first four-way valve and a second four-way valve, the first four-way valve is arranged on the second pipeline, and the second four-way valve is arranged on the third pipeline.

During a normal operation, a refrigeration cycle device is switched to a refrigerant circuit in which heat contained in a high-pressure refrigerant flowing out of an interior radiator is stored in a heat storage member. When frost is formed on an evaporator, the refrigeration cycle device is switched to another refrigerant circuit in which the exterior heat exchanger is heated and defrosted using heat stored in the heat storage member as a heat source. The heat storage member uses a material formed by adding W (tungsten) as an additive to VO.sub.2 (vanadium dioxide) which is a transition metal oxide having a property of a phase transition between a metal and an insulator. The heat storage member effectively stores or dissipates heat depending on a temperature zone of the refrigerant, thereby suppressing an increase in energy consumption of a compressor.

An outdoor unit for a heat pump includes a refrigerant circuit, the outdoor unit including a compressor, a discharge pipe of the refrigerant circuit connected to a discharge side of the compressor, a bottom plate, the bottom plate having a base and an outer flange protruding upward from an outer edge of the base, a heat source heat exchanger supported on the bottom plate, a liquid refrigerant pipe of the refrigerant circuit connected to the heat source heat exchanger, and a defrosting bypass pipe connected at one end to the discharge pipe and at the opposite end to the liquid refrigerant pipe, the defrosting bypass pipe being arranged between an inner side of the flange and an outer side of the heat source heat exchanger.

Provided is an air-conditioning apparatus including a switching valve and a bypass circuit. The switching valve is provided between an expansion valve and an outdoor heat exchanger. The bypass circuit has a first end connected to a refrigerant pipe connecting a compressor and an indoor heat exchanger to each other, and a second end connected to the switching valve. During a heating operation, the air-conditioning apparatus causes a rotating member of the switching valve to rotate to sequentially connect, to the bypass circuit, flow passages of the outdoor heat exchanger connected in parallel, to thereby defrost the outdoor heat exchanger while performing the heating operation.