An air-conditioning apparatus includes a suction-injection pipe that introduces a refrigerant in a liquid or two-phase state into a suction side of a compressor, an expansion device that is arranged at the suction-injection pipe, and a controller that regulates the suction-injection flow rate of a refrigerant introduced into the suction side of the compressor through the suction-injection pipe by controlling the opening degree of the expansion device.

An air-conditioning apparatus includes a compressor, a four-way valve, expansion means, and an indoor heat exchanger, and further includes a check valve disposed between a discharge side of the compressor and the four-way valve, a first solenoid valve disposed between the expansion means and the indoor heat exchanger, and a controller. Opening and closing of the first solenoid valve are controllable. The controller switches the four-way valve and switches the first solenoid valve between open and closed states. When a heating operation is stopped, the controller switches the four-way valve from connection for the heating operation to connection for a cooling operation, closes the first solenoid valve, and then stops the compressor.

A refrigeration cycle apparatus includes a compressor, a condenser, a first subcooling device that subcools a refrigerant by exchanging heat with the air, a second subcooling device that performs a heat exchange between refrigerant streams that have been branched by a branch pipe, thereby subcooling one of the refrigerant streams, a flow control device that adjusts a flow rate of the second stream of the refrigerant and passes this refrigerant through the second subcooling device, a bypass path that allows the refrigerant passing through the flow control device and the second subcooling device to flow therethrough, an expansion valve, an evaporator, and a controller configured to control an amount of heat exchanged in the first subcooling device and an amount of heat exchanged in the second subcooling device based on a temperature of the air.

A heat pump device is provided with: a first refrigerant guide-in unit that guides in the high temperature, high pressure refrigerant discharged by the compressor from outside the housing; a water refrigerant heat exchanger that can dissipate heat from the high temperature, high pressure refrigerant guided in from the first refrigerant guide-in unit into a cooling fluid; and a housing accommodating the water refrigerant heat exchanger. The heat pump device is further provided with a cooling fluid guide-in unit that can guide the cooling fluid from outside the housing into the water refrigerant heat exchanger, a cooling fluid guide-out unit that can guide the cooling fluid out of the water refrigerant heat exchanger to the outside of the housing, and a first refrigerant guide-out unit that guides the refrigerant that has passed through the water refrigerant heat exchanger to the outside of the housing.

The present disclosure relates to apparatuses and methods for multi-phase vacuum-assisted recovery of refrigerant from a vehicle. One apparatus for multi-phase vacuum-assisted recovery of refrigerant from a vehicle includes a compressor that removes refrigerant from the vehicle during a first phase and a second phase of a recovery process. The apparatus also includes one or more pressure sensitive devices that are each configured to measure a first pressure and/or a second pressure in the apparatus. Upon the first pressure being less than a first threshold pressure, a vacuum pump that is fluidly connected in series with the compressor assists the compressor in the removal of refrigerant from the vehicle during a second stage of the recovery process. Also, upon the second pressure being less than a second threshold pressure, the vacuum pump ceases assisting the compressor.

A method is provided for managing a flooded start of a compressor in a vapor compression system. Following an initial bump start, a determination is made as to whether working fluid in a liquid state remains in the sump of the compressor. If working fluid in a liquid state remains in the compressor sump, an additional bump start of the compressor is completed, followed by another determination as to whether working fluid in a liquid state still remains in the compressor sump. If working fluid in a liquid state remains in the compressor sump, another bump start of the compressor is initiated and the sequence repeated until no working fluid in the liquid state remains in the compressor sump. A normal start of the compressor may be initiated after determining no working fluid in the liquid state remains in the compressor sump.

A refrigeration system has: (a) a fluid tight circulation loop including a compressor, a condenser and an evaporator, the evaporator having at least three evaporator zones, each evaporator zone having an inlet port, the circulation loop being further configured to measure the condition of the refrigerant with a refrigerant condition sensor disposed within the evaporator upstream of the evaporator outlet port; and control the flow of refrigerant to the evaporator based upon the measured condition of the refrigerant within the evaporator, and (b) a controller for controlling the flow rate of refrigerant to the evaporator based upon the measured condition of the refrigerant within the evaporator upstream of the evaporator outlet port.

A refrigeration system includes a valve and a controller. The valve is configured to control the flow of refrigerant into an evaporator, the refrigerant having an associated liquid setting comprising a temperature and a pressure at which the refrigerant flows through the valve. The controller is operable to adjust the liquid setting, the adjusted liquid setting comprising a temperature and a pressure selected to improve energy efficiency under conditions currently being experienced by the refrigeration system, wherein the controller is operable to adjust the temperature and the pressure simultaneously such that the adjustment does not interfere with operation of the valve.

A vehicle air conditioning apparatus includes an outdoor expansion valve controller configured to control an evaporating temperature of a refrigerant in a heat exchanger by regulating an opening of an outdoor expansion valve during a heating and dehumidifying operation, an evaporating temperature control valve provided in a refrigerant flow passage to an output side of the heat exchanger from which the refrigerant is discharged, and configured to control the evaporating temperature of the refrigerant in the heat exchanger by regulating an amount of the refrigerant flowing through the refrigerant flow passage, a temperature detector configured to detect a temperature of the refrigerant in the heat exchanger, and a control changer configured to change control of the evaporating temperature of the refrigerant in the heat exchanger from by regulating an opening of the outdoor expansion valve to by regulating an opening of the evaporating temperature control valve.

A variable refrigerant volume system and control method thereof. The variable refrigerant volume system comprises: a compressor (1); a four-way valve (19); an indoor unit; a liquid tube (22), the first end thereof being connected to the indoor unit, the second end thereof being connected to the third valve port of the four-way valve (19), and a condenser (18) being provided on the liquid tube (22); a low pressure air pipe (23), the first end thereof being connected to the indoor unit, and the second end thereof being connected to the fourth valve port of the four-way valve (19); a refrigerant adjustment tank (6), the first port thereof being connected to the liquid tube (22), the second port thereof being connected to the low pressure air pipe (23), and the third port thereof optionally communicating with the liquid tube (22) or the low pressure air pipe (23). The refrigerant adjustment tank (6) provides refrigerant to the variable refrigerant volume system when the system requires more refrigerant, and recycles refrigerant from the variable refrigerant volume system when the system requires less refrigerant. The variable refrigerant volume system can flexibly control a refrigerant recycling amount in accordance with a refrigerant operation situation, thus ensuring system reliability.