An air conditioning system is provided. The system has a high-pressure pipe, a low-pressure pipe, an indoor heat exchanger, an outdoor heat exchanger, a leak-free thermal expansion valve and a variable capacity compressor. The variable capacity compressor has a shell, a first cylinder and a second cylinder. The shell has a suction port and an exhaust port. The first cylinder has a first suction hole connected to the suction port and a first exhaust hole connected to the exhaust port. The second cylinder has a second suction hole connected to the suction port, a second exhaust hole connected to the exhaust port, and a pressure relief hole connected to the high-pressure pipe and the low-pressure pipe in an on-off manner. Before the variable capacity compressor is started, the high-pressure pipe and the low-pressure pipe are connected and also disconnected after the first preset duration.

A system for cooling a plurality of processors in a data center is disclosed. The cooling system includes a refrigeration system having a compressor for compressing a carbon dioxide (CO2) working fluid, an air cooled heat exchanger downstream from the compressor and located out-of-doors for cooling the working fluid, an expansion device downstream from the heat exchanger, a cooling device located within the data center in which the working fluid is expanded to cool the processors by circulating the cooled air around the processors, and a return line for the return of the working fluid from the cooling device to the compressor.

A system for cooling a plurality of processors in a data center is disclosed. The cooling system includes a refrigeration system having a compressor for compressing a carbon dioxide (CO2) working fluid, an air cooled heat exchanger downstream from the compressor and located out-of-doors for cooling the working fluid, an expansion device downstream from the heat exchanger, a cooling device located within the data center in which the working fluid is expanded to cool the processors by circulating the cooled air around the processors, and a return line for the return of the working fluid from the cooling device to the compressor.

Thermal management systems include an open circuit refrigeration system featuring a first receiver configured to store a gas, a second receiver configured to store a liquid refrigerant fluid, an evaporator configured to extract heat from a heat load that contacts the evaporator, and an exhaust line, where the first receiver, the second receiver, the evaporator, and the exhaust line are connected to provide a refrigerant fluid flow path.

Thermal management systems include an open circuit refrigeration system featuring a first receiver configured to store a gas, a second receiver configured to store a liquid refrigerant fluid, an evaporator configured to extract heat from a heat load that contacts the evaporator, and an exhaust line, where the first receiver, the second receiver, the evaporator, and the exhaust line are connected to provide a refrigerant fluid flow path.

An electronic expansion valve and an assembly method therefor. The electronic expansion valve includes a screw rod component, a movable connection component, a valve pin component and an elastic element. One end of the elastic element abuts the movable connection component, and the other end thereof abuts the valve pin component. In the period from the valve pin component closing the valve port part to the screw rod component moving a pre-set displacement amount in the valve closing direction, the elastic element does not generate an elastic force pushing the valve pin component towards the valve port part; and in the period from the valve pin component closing the valve port part to in a case that the screw rod component moving more than the pre-set displacement amount in the valve closing direction, the elastic element generates an elastic force pushing the valve pin component towards the valve port part.

A refrigeration cycle apparatus according to the present invention performs cooling by circulation of refrigerant. The refrigeration cycle apparatus includes an evaporator, a condenser, a pump, a compressor, and a controller. The evaporator is arranged in a first space. The condenser is arranged in a second space. The pump is configured to compress refrigerant from the condenser and output the refrigerant to the evaporator. The compressor is configured to compress refrigerant from the evaporator and output the refrigerant to the condenser. The controller is configured to control the pump and the compressor to cool the first space. The controller is configured to turn on the pump after turn-on of the compressor while a temperature of the first space is higher than a temperature of the second space.

A refrigeration cycle apparatus according to the present invention performs cooling by circulation of refrigerant. The refrigeration cycle apparatus includes an evaporator, a condenser, a pump, a compressor, and a controller. The evaporator is arranged in a first space. The condenser is arranged in a second space. The pump is configured to compress refrigerant from the condenser and output the refrigerant to the evaporator. The compressor is configured to compress refrigerant from the evaporator and output the refrigerant to the condenser. The controller is configured to control the pump and the compressor to cool the first space. The controller is configured to turn on the pump after turn-on of the compressor while a temperature of the first space is higher than a temperature of the second space.

Refrigeration systems are described. The systems include a refrigeration circuit having a compression device, a heat rejecting heat exchanger, an expansion device, and a heat absorbing heat exchanger. The refrigeration systems include one or more sensors configured to measure a pressure associated with the heat rejecting heat exchanger, and a controller configured to compare the pressure measured by the one or more sensors to a predicted pressure, and to control the expansion device on the basis of the comparison.

Refrigeration systems are described. The systems include a refrigeration circuit having a compression device, a heat rejecting heat exchanger, an expansion device, and a heat absorbing heat exchanger. The refrigeration systems include one or more sensors configured to measure a pressure associated with the heat rejecting heat exchanger, and a controller configured to compare the pressure measured by the one or more sensors to a predicted pressure, and to control the expansion device on the basis of the comparison.