Abstract: A refrigeration cycle device includes a third refrigerant passage connecting a utilization heat exchanger to a first expansion valve, a fourth refrigerant passage connecting the first expansion valve to a receiver, a fifth refrigerant passage connecting the receiver to a second expansion valve, a sixth refrigerant passage connecting the second expansion valve to an air heat exchanger, a hot-gas bypass passage connecting a discharge passage to the sixth refrigerant passage, a hot-gas bypass valve, an internal heat exchanger to exchange heat between the liquid refrigerant inside the receiver and the refrigerant passing through the suction passage, a liquid bypass passage including an inlet portion connected to the fourth refrigerant passage, the fifth refrigerant passage, or a lower portion of the receiver, and an outlet portion connected to the suction passage upstream of the internal heat exchanger, and a liquid bypass valve.

Abstract: A refrigeration cycle apparatus includes: a casing; an air handling unit accommodated in the casing and including a first duct and a first outlet, a second duct and a second outlet, a first fan and a second fan; and a refrigerant circuit configured to circulate refrigerant in the refrigerant circuit and including a first heat exchanger and a second heat exchanger.

Abstract: A refrigeration cycle apparatus includes: a casing; an air handling unit accommodated in the casing and including a first duct and a first outlet, a second duct and a second outlet, a first fan and a second fan; and a refrigerant circuit configured to circulate refrigerant in the refrigerant circuit and including a first heat exchanger and a second heat exchanger.

Abstract: An outdoor unit of an air-conditioning apparatus includes a housing, a compressor disposed in the housing, an outdoor heat exchanger through which refrigerant supplied from the compressor flows, an air-sending device that sends air to the outdoor heat exchanger, an electric component box including an electric component that controls the compressor, a dividing plate that separates the compressor from an air-sending chamber accommodating the air-sending device, an electric component mount disposed above the compressor to partition a mechanical chamber accommodating the compressor from an electric component chamber accommodating the electric component box, and a support part for the electric component mount provided on an inner wall of the housing along an outer circumferential shape of the electric component mount to project toward an interior of the housing.

Abstract: An air-conditioning-apparatus outdoor unit includes a casing, an air-sending device chamber, a machine chamber, a partition, a heat exchanger cover, and an electric box including a bottom plate that defines a bottom surface of the electric box and that is joined to an upper end of the heat exchanger cover. The casing includes a shell panel having an outdoor-air inlet that is open. The heat exchanger cover is positioned to face the outdoor-air inlet, and defines, together with the partition and the shell panel, an air passage communicating with the outdoor-air inlet in the machine chamber. The bottom plate of the electric box has a bottom opening communicating with the air passage.

Abstract: A plate heat exchanger includes a plate stack including a plurality of heat transfer plates stacked with each other. Each of the heat transfer plates includes a heat medium inflow hole serving as an inlet for a heat medium, a heat medium outflow hole serving as an outlet for the heat medium, a refrigerant inflow hole serving as an inlet for refrigerant, and a refrigerant outflow portion located below the refrigerant inflow hole and serving as an outlet for the refrigerant. The heat transfer plates define heat medium passages, through each of which the heat medium flowing from the heat medium inflow hole flows, and refrigerant passages, through each of which the refrigerant flowing from the refrigerant inflow hole flows downward, arranged alternately with one another. Each of the heat medium passages and the refrigerant passages is defined between adjacent ones of the heat transfer plates.

Abstract: In a refrigeration cycle apparatus, a refrigerant heat exchanger is provided within a refrigerant container, and the refrigerant heat exchanger is configured to exchange heat between refrigerant flowing through a bypass circuit and refrigerant accumulated in the refrigerant container.

Abstract: A plate heat exchanger includes a plate stack including a plurality of heat transfer plates stacked with each other. Each of the heat transfer plates includes a heat medium inflow hole serving as an inlet for a heat medium, a heat medium outflow hole serving as an outlet for the heat medium, a refrigerant inflow hole serving as an inlet for refrigerant, and a refrigerant outflow portion located below the refrigerant inflow hole and serving as an outlet for the refrigerant. The heat transfer plates define heat medium passages, through each of which the heat medium flowing from the heat medium inflow hole flows, and refrigerant passages, through each of which the refrigerant flowing from the refrigerant inflow hole flows downward, arranged alternately with one another. Each of the heat medium passages and the refrigerant passages is defined between adjacent ones of the heat transfer plates.

Abstract: An air-conditioning-apparatus outdoor unit includes a casing, an air-sending device chamber, a machine chamber, a partition, a heat exchanger cover, and an electric box including a bottom plate that defines a bottom surface of the electric box and that is joined to an upper end of the heat exchanger cover. The casing includes a shell panel having an outdoor-air inlet that is open. The heat exchanger cover is positioned to face the outdoor-air inlet, and defines, together with the partition and the shell panel, an air passage communicating with the outdoor-air inlet in the machine chamber. The bottom plate of the electric box has a bottom opening communicating with the air passage.

Abstract: An outdoor unit of an air-conditioning apparatus includes a housing, a compressor disposed in the housing, an outdoor heat exchanger through which refrigerant supplied from the compressor flows, an air-sending device that sends air to the outdoor heat exchanger, an electric component box including an electric component that controls the compressor, a dividing plate that separates the compressor from an air-sending chamber accommodating the air-sending device, an electric component mount disposed above the compressor to partition a mechanical chamber accommodating the compressor from an electric component chamber accommodating the electric component box, and a support part for the electric component mount provided on an inner wall of the housing along an outer circumferential shape of the electric component mount to project toward an interior of the housing.

Abstract: A plate heat exchanger can reduce thermal contact between a second fluid (water and a third fluid (low-temperature, low-pressure two-phase refrigerant) to enhance thermal efficiency. A plate heat exchanger includes a heat transfer plate group that performs heat exchange between a first fluid of high-temperature, high-pressure gas refrigerant and a second fluid of a heating target fluid; and a heat transfer plate group that performs heat exchange between a first fluid of low-temperature, high-pressure liquid refrigerant and a third fluid of low-temperature, low-pressure two-phase liquid refrigerant. The heat transfer plate group forms refrigerant channels including a stack of plates, has a configuration that a flow of the first fluid of high-temperature, high-pressure gas refrigerant and a flow of the second fluid are alternately aligned in the refrigerant channels, and causes the second fluid to flow in the outermost refrigerant channel.

Abstract: An air-conditioning apparatus includes a fan configured to deliver air toward the outdoor heat exchanger, a power unit configured to supply electric power to the fan, a fan input detector configured to detect a physical value related to the electric power supplied to the fan, and a controller configured to control the four-way valve to switch between a first operation in which the outdoor heat exchanger functions as an evaporator and a second operation in which the outdoor heat exchanger functions as a condenser. The first operation is switched to the second operation when the physical value detected by the fan input detector is equal to or larger than a reference value. The controller adjusts the reference value so that the reference value when refrigerant flowing through the outdoor heat exchanger has a high temperature is smaller than the reference value when the refrigerant has a low temperature.

Abstract: A plate heat exchanger includes a plurality of rectangular plates each having, at four corners thereof, inlets and outlets and others for a first fluid and a second fluid. The plates are stacked such that first passages each defined by adjacent two of the plates and through which the first fluid flows and second passages each defined by adjacent two of the plates and through which the second fluid flows are provided alternately. The first passage includes a bypass passage extending from an inlet peripheral portion, which is an area around the inlet, along the outlet for the second fluid up to a long-side-peripheral portion of the plate that is nearer to the second outlet. The bypass passage allows some of the first fluid having flowed therein from the inlet to flow from the long-side-peripheral portion into a heat-exchanging passage.

Abstract: A plate heat exchanger can reduce thermal contact between a second fluid (water and a third fluid (low-temperature, low-pressure two-phase refrigerant) to enhance thermal efficiency. A plate heat exchanger (1b) includes a heat transfer plate group (102a) that performs heat exchange between a first fluid of high-temperature, high-pressure gas refrigerant and a second fluid of a heating target fluid; and a heat transfer plate group (102b) that performs heat exchange between a first fluid of low-temperature, high-pressure liquid refrigerant and a third fluid of low-temperature, low-pressure two-phase liquid refrigerant. The heat transfer plate group (102a) forms refrigerant channels including a stack of plates, has a configuration that a flow of the first fluid of high-temperature, high-pressure gas refrigerant and a flow of the second fluid are alternately aligned in the refrigerant channels, and causes the second fluid to flow in the outermost refrigerant channel.

Abstract: In a refrigeration cycle apparatus, a refrigerant heat exchanger is provided within a refrigerant container, and the refrigerant heat exchanger is configured to exchange heat between refrigerant flowing through a bypass circuit and refrigerant accumulated in the refrigerant container.

Abstract: It is an object to prevent a liquid refrigerant from being drawn into a compressor. A heat pump apparatus includes a refrigerant circuit in which a refrigerant circulates, and which is configured by sequentially connecting a compressor, a first heat exchanger, an expansion valve, a second heat exchanger, and a third heat exchanger, and connecting a bypass flow path bypassing the third heat exchanger between the second heat exchanger and the compressor. The heat pump apparatus also includes a water circuit in which water circulates, and which is configured by sequentially connecting the third heat exchanger, the first heat exchanger, and a tank. In the heat pump apparatus, if there is a risk of the liquid refrigerant being drawn into the compressor, a three-way valve is controlled such that the refrigerant flows through the third heat exchanger to be heated by water and evaporated.

Abstract: In a heat pump apparatus, it is aimed to enhance efficiency of a defrost operation by reducing a loss of heat radiation during the defrost operation and reducing a compressor input during the defrost operation. The heat pump apparatus includes a main refrigerant circuit in which a compressor, a first heat exchanger, an expansion mechanism, and a second heat exchanger are connected sequentially, and also includes a bypass circuit including an on-off valve and providing a connection by bypassing the expansion mechanism. The main refrigerant circuit includes a four-way valve that switches between a heating operation and the defrost operation by switching an order in which the refrigerant circulates through the main refrigerant circuit. The main refrigerant circuit also includes a first temperature detection unit and a second temperature detection unit. Based on values detected by these temperature detection units, a degree of superheat of the first heat exchanger during the defrost operation is computed.

Abstract: When using a plurality of heaters such as heat pump units, capacity is properly distributed according to the required capacity, thereby enabling highly efficient operation of a hot water system. To achieve this, a control apparatus determines the heating capacity of each of the heat pump units in a way that the total heating capacity of the heat pump units reaches the heating capacity required in the hot water system as a whole, and further in a way that the total COP (coefficient of performance) of the heat pump units satisfies predetermined condition. The control apparatus controls each of regulating valves in a way that the heating capacity of each of the heat pump units reaches the above determined heating capacity.

Abstract: A plate heat exchanger includes a stack of a plurality of plates each having an inlet and an outlet for a fluid. Each adjacent two of the plates are bonded to each other at regions thereof where top parts of the wavy portion provided in a lower one of the plates and bottom parts of the wavy portion provided in an upper one of the plates overlap each other when seen in the stacking direction. Particularly, a top part included in the top parts of the wavy portion of the lower plate and being adjacent to each of the inlet and the outlet has a planar shape.

Abstract: A heat pump apparatus includes a refrigerant circuit in which a compressor, a condenser, expansion means, and an evaporator are serially connected. Condensation temperature detection means that detects a saturation temperature of the condenser, and evaporation temperature detection means that detects the saturation temperature of the evaporator are provided. Operation efficiency is estimated by a value obtained by dividing heating ability estimated from a detection value of the condensation temperature detection means by a difference between a detection value of condensation temperature detection means and that of evaporation temperature detection means or dissipation power estimated by the difference.