An outdoor unit is connected to a refrigerator and has two compressors that are connected in series, and a control method thereof. The outdoor unit according to an embodiment of the present invention includes a low pressure side compressor for compressing a refrigerant; a high pressure side compressor for compressing the refrigerant compressed by the low pressure side compressor; an outdoor heat exchanger for condensing the refrigerant compressed by the high pressure side compressor; a heat recovery unit for cooling the refrigerant condensed in the outdoor heat exchanger by exchanging heat with the refrigerant evaporated in the air conditioner; and a supercooler for expanding a part of the refrigerant cooled in the heat recovery unit to cool another part of the refrigerant cooled in the heat recovery unit, so that the discharge temperature of the low pressure side compressor and/or the high pressure side compressor can be reduced.

A mechanical subcooling system operatively connectable to a transcritical R-744 refrigeration system resulting in an energy efficiency ratio of a level comparable to that of refrigeration systems using common refrigerants. Mechanical subcooling increases the refrigeration capacity without increasing the power consumption of the refrigeration system's compressors. The compressors used to provide the refrigeration capacity for the subcooling process operate at much more favorable conditions, thus having a very high energy efficiency ratio. The result is higher refrigeration capacity and lower power consumption.

An air conditioning apparatus includes: a supercooling heat exchanger configured to supercool refrigerant flowing in a first flow path between an outdoor heat exchanger and an expansion valve; a flow path switching valve configured to switch a flow path between an indoor heat exchanger and a compressor to one of a second flow path that does not extend through the supercooling heat exchanger and a third flow path that extends through the supercooling heat exchanger; a bypass circuit that is branched from the first flow path and extends through the supercooling heat exchanger; and a bypass regulating valve provided in the bypass circuit; and a controller. In a cooling operation, when a load is not low, the controller selects the second flow path and opens the bypass regulating valve, whereas when the load is low, the controller selects the third flow path and closes the bypass regulating valve.

There is disclosed a vehicular air-conditioning device of a so-called heat pump system which eliminates or decreases noise generated when an opening/closing valve opens at a changing time of an operation mode. The vehicular air-conditioning device executes a heating mode to let a refrigerant discharged from a compressor 2 radiate heat in a radiator 4, decompress the refrigerant by which heat has been radiated, and then let the refrigerant absorb heat in an outdoor heat exchanger 7, and a dehumidifying and heating mode to open a solenoid valve 22 in a state of the heating mode, decompress at least a part of the refrigerant flowing out from the radiator and then let the refrigerant absorb heat in a heat absorber 9. When the heating mode changes to the dehumidifying and heating mode, the controller decreases a radiator pressure or a pressure difference before and after the solenoid valve to a predetermined value or less, and then opens the solenoid valve 22.

A device for heat distribution in a hybrid motor vehicle includes an engine cooling circuit and a refrigerant circuit for a combined operation in a refrigeration heat pump mode and a reheating mode. The refrigerant circuit includes an evaporator, a compressor, a heat exchanger to supply heat from the refrigerant to air being conditioned for a passenger compartment, and a heat exchanger to transfer heat between a refrigerant of the refrigerant circuit and coolant of the engine cooling circuit. The heat exchanger operates as an evaporator for the heat transfer from the coolant to the evaporating refrigerant, and alternatively operates as a condenser for the heat transfer from the condensing refrigerant to the coolant.

A mechanical subcooling system operatively connectable to a transcritical R-744 refrigeration system resulting in an energy efficiency ratio of a level comparable to that of refrigeration systems using common refrigerants. Mechanical subcooling increases the refrigeration capacity without increasing the power consumption of the refrigeration system's compressors. The compressors used to provide the refrigeration capacity for the subcooling process operate at much more favorable conditions, thus having a very high energy efficiency ratio. The result is higher refrigeration capacity and lower power consumption.

An apparatus includes a heat exchanger, a load, a compressor, and a valve. The heat exchanger receives a refrigerant at a first inlet and directs the refrigerant received at the first inlet to an outlet. The load uses the refrigerant from the outlet to remove heat from a space proximate the load. The compressor compresses the refrigerant from the load. The valve directs the refrigerant from the compressor to a second inlet of the heat exchanger when a temperature of the refrigerant at the load is below a first threshold. The heat exchanger transfers heat from the refrigerant received at the second inlet to the refrigerant received at the first inlet.

A method of cooling a refrigerant includes providing a condenser (200) including a condenser shell (202) that contains a condenser chamber (204), a condensing conduit (209), and a cooling conduit (217); condensing a refrigerant within the condenser chamber (204) from a vapour phase to a liquid phase by exchanging heat from the refrigerant in the condenser chamber (204) to a fluid in the condensing conduit (209); supplying a first portion of the condensed refrigerant to the cooling conduit (217) via a first expansion valve (310) such that the first portion of the refrigerant decreases in pressure and temperature before entering the cooling conduit (217); and cooling the refrigerant in the condenser chamber (204) by exchanging heat from the refrigerant in the condenser chamber (204) to the first portion of the refrigerant in the cooling conduit (217).

A refrigerator, comprising a cooling loop. The cooling loop has a first flow path in which a compressor, a condenser, a capillary tube, and an evaporator are sequentially connected for circulating a refrigerant. The cooling loop comprises: a hot gas bypass tube, configured to form a second flow path that enables the refrigerant compressed by the compressor to flow from the compressor to the evaporator; a three-way valve, provided in the first flow path between the compressor and the condenser and connected to the hot gas bypass tube; and a two-way valve, provided in the first flow path between the condenser and the capillary tube. The three-way valve can enable the refrigerant discharged from the compressor to flow to the condenser or the hot gas bypass tube, and the two-way valve can be switched off to cut off the flow of the refrigerant discharged from the condenser.

An apparatus includes a heat exchanger, a load, a compressor, and a valve. The heat exchanger receives a refrigerant at a first inlet and directs the refrigerant received at the first inlet to an outlet. The load uses the refrigerant from the outlet to remove heat from a space proximate the load. The compressor compresses the refrigerant from the load. The valve directs the refrigerant from the compressor to a second inlet of the heat exchanger when a temperature of the refrigerant at the load is below a first threshold. The heat exchanger transfers heat from the refrigerant received at the second inlet to the refrigerant received at the first inlet.