A two-stage pressure buildup refrigeration cycle apparatus has a low-pressure side compressor, a high-pressure side compressor, and a controller. The controller controls, for improving a COP, the low-pressure side compressor and the high-pressure side compressor in a COP improving operation mode in which a refrigerant discharge capacity of one of the low-pressure side compressor and the high-pressure side compressor is set based on a refrigerant discharge capacity of an other of the low-pressure side compressor and the high-pressure side compressor, when a required level of a refrigeration performance is low. The controller controls the low-pressure side compressor and the high-pressure side compressor in a high performance operation mode in which a refrigerant discharge capacity of the high-pressure side compressor is increased after increasing a refrigerant discharge capacity of the low-pressure side compressor, when the required level of the refrigeration performance is high.

A cooling system for cooling a machine tool having a machine temperature. The cooling system comprises gas source, refrigeration circulation, fan, and controller. The gas source is configured for providing gas. The refrigeration circulation comprises heat exchanger, compressor, condenser, and expansion valve. The heat exchanger is in fluid communication with the gas source and configured to cool the gas down to target temperature and to provide the gas to the machine tool. The compressor has operation frequency. The fan is configured to cool the condenser and has a rotation speed. The controller is connected to the compressor and the fan. When a target temperature difference that is equal to the machine temperature minus the target temperature is smaller than threshold temperature difference, the controller keeps the operation frequency at minimum frequency and sets the rotation speed to be smaller than a maximum rotation speed.

A refrigeration system includes a receiver, a gas bypass valve, a parallel compressor, and a controller. The gas bypass valve and the parallel compressor are fluidly coupled to an outlet of the receiver in parallel and configured to control a pressure of a gas refrigerant in the receiver. The controller is configured to switch from operating the gas bypass valve to operating the parallel compressor to control the pressure of the gas refrigerant in the receiver in response to a value of a process variable crossing a switchover setpoint. The value of the process variable depends on an amount of the gas refrigerant produced by the refrigeration system. The controller is configured to automatically adjust the switchover setpoint in response to the amount of the gas refrigerant produced by the refrigeration system being insufficient to sustain operation of the parallel compressor.

An air-conditioning apparatus includes a first flow switching unit configured to be switched between a first state in which refrigerant communication between a compressor and a second load-side heat exchanger is blocked and a second state in which the compressor is in refrigerant communication with a first load-side heat exchanger and the second load-side heat exchanger. The air-conditioning apparatus further includes a second flow switching unit configured to be switched between a third state in which refrigerant communication between the second load-side heat exchanger and a heat-source-side heat exchanger is blocked and a fourth state in which the first load-side heat exchanger is in refrigerant communication with the second load-side heat exchanger and the heat-source-side heat exchanger. The first heat exchanger is located upstream of the second load-side heat exchanger. The second flow switching unit is located downstream of the second load-side heat exchanger.

Provided are a programmable motor and a household appliance having the same. The programmable motor comprises a main body (21) and a driving device (22) comprising a reprogramming interface. When performing reprogramming on the programmable motor, the reprogramming interface communicates with a programming device to receive a motor parameter or a motor software program, to transmit the same to the driving device (22), and to update the motor parameter or the motor software program in the driving device (22). The method realizes rewriting of a motor software program and realizes reprogramming of a motor by directly inserting a programming device into a reprogramming interface of a driving device (22) without having to disassemble the driving device (22), thereby effectively reducing post-sale costs associated with a motor, and improving post-sale efficiency associated with the motor.

A heat pump configured by connecting a circuit including a variable capacity compressor, a condenser, an expansion valve, and an evaporator through a closed refrigerant line, includes a condenser fan, an evaporator fan, a refrigerant amount adjusting means for charging or recovering a refrigerant in or from the circuit, and a controller. Roles of the controller include setting a target pressure inside an outdoor heat exchanger y referring to an outside temperature and a load, setting a target pressure inside an indoor heat exchanger by referring to an inside temperature and a set temperature, setting a target sub-cooling degree and a target super-heating degree, and controlling both of the fans to either adjust temperature or adjust pressure.

A dehumidifying system and method for reducing humidity in ambient air is disclosed. The system includes a circulation unit, a refrigeration unit, a condensate receptacle for receiving condensate generated by the refrigeration unit, a controller to control both the circulation and refrigeration units, and wherein the controller receives input from one or more ambient sensors configured to sense ambient conditions, and a user interface configured to receive input from a user. The system implements variable speed control within the circulation and/or refrigeration unit to maximize efficiency or capacity under a current threshold, and enables the system to delay the need for defrost cycling during low temperature operation.

A refrigeration system for a temperature-controlled storage device includes a refrigeration circuit, a cooling circuit, and a controller. The refrigeration circuit includes a compressor driven by a brushless DC motor operable at multiple different speeds, a first heat exchanger, an expansion device, and a cooling unit in fluid communication via a first working fluid. The cooling circuit includes a pump and a second heat exchanger in fluid communication with the first heat exchanger via a second working fluid such that the first heat exchanger is liquid-cooled by the second working fluid. The controller operates the brushless DC motor at multiple different speeds to accommodate multiple different thermal loads experienced by the refrigeration system. Each of the speeds corresponds to a different thermal load. The controller modulates the speed of the brushless DC motor to maintain a desired temperature of a temperature-controlled space within the temperature-controlled device.

A compressed air drying system is provided for removing moisture from compressed air. The dryer operates in two modes in response to the demand for compressed air. In a first mode of operation, a refrigeration compressor runs continuously and the speed of a condenser fan is varied to maintain a constant cooling temperature. In a second mode of operation, the refrigeration compressor runs intermittently between on and off periods. As result, the cooling temperature fluctuates during the second mode of operation.

A part of a gas-phase mixed refrigerant compressed by a compressor (20) is condensed by a first condenser (21). Then, the mixed refrigerant is separated by a first gas-liquid separator (22) into a gas-phase first fluid portion (I) and a liquid-phase second fluid portion (II) which has been condensed into a liquid phase. A part of the gas-phase first fluid portion (I) is further condensed by a second condenser (23). Then, the first fluid portion is further separated by a second gas-liquid separator (24) into a gas-phase third fluid portion (III) and a liquid-phase fourth fluid portion (IV) which has been condensed into a liquid phase. Thereafter, the gas-phase third fluid portion (III) is condensed and then expanded.