A refrigeration cycle apparatus includes a refrigeration cycle in which refrigerant circulates, the refrigeration cycle including a compressor, an outdoor heat exchanger, expansion valves, and indoor heat exchangers, which are connected to each other via a refrigerant pipe, a heat source unit accommodating the outdoor heat exchanger, use-side units accommodating the indoor heat exchangers, and a control unit that controls at least turning on and off of the refrigeration cycle. The control unit detects abnormality of the refrigeration cycle based on the pressure or temperature of the refrigeration cycle in an off time of the refrigeration cycle.

An electronic expansion valve is provided, wherein a piston component and a valve needle component are located at the same side of a valve core seat. When refrigerant flows forwards, the piston component closes the bypass through hole, the refrigerant flows to a side of the vertical connecting pipe via the valve core valve port, and the valve needle component moves in the axial direction to regulate an opening of the valve core valve port. When the refrigerant flows reversely, the piston component moves upwards in the axial direction to open the bypass through hole, and the refrigerant flows to a side of the transverse connecting pipe via the bypass through hole. The electronic expansion valve ensures that the valve needle component seals the valve core valve port easily in a high pressure state when the refrigerant flows forwards, and reduces axial and radial dimensions of the valve seat.

A system includes a cryocooler configured to cool an object, a sensor configured to measure a temperature of the object, and a controller configured to generate an actuator drive signal to control the cryocooler based on at least one temperature measurement from the sensor. The cryocooler includes a heat exchanger and a needle configured to control flow of coolant gas through the heat exchanger. The cryocooler also includes a motion rod configured to move the needle and an actuator assembly configured to move the motion rod to thereby move the needle. The actuator could include a motor and a gear head configured to rotate a lead screw and a lead screw nut located around the lead screw and configured to translate rotational motion of the lead screw into linear motion. The actuator could also include a piezoelectric actuator or a linear actuator.

A system has a compressor, a heat rejection heat exchanger, first and second ejectors, first and second heat absorption heat exchangers, and a separator. The ejectors each have a primary inlet coupled to the heat rejection exchanger to receive refrigerant. A second heat absorption heat exchanger is coupled to the outlet of the second ejector to receive refrigerant. The separator has an inlet coupled to the outlet of the first ejector to receive refrigerant from the first ejector. The separator has a gas outlet coupled to the secondary inlet of the second ejector to deliver refrigerant to the second ejector. The separator has a liquid outlet coupled to the secondary inlet of the first ejector via the first heat absorption heat exchanger to deliver refrigerant to the first ejector.

An electronic expansion valve (1-100) is provided. The electronic expansion valve (1-100) includes: a screw (1-31), a valve needle (1-22), and an elastic member (1-25). One end of the elastic member (1-25) acts on the screw (1-31) and the other end acts on the valve needle (1-22). A bearing (1-23) is arranged between the screw (1-31) and the valve needle (1-22). The bearing (1-23) has an inner ring and an outer ring. One of the screw (1-31) and the valve needle (1-22) is fixed with the inner ring of the bearing (1-23), and the other acts on the outer ring of the bearing (1-23) through the elastic member (1-25). An air conditioning system using the electronic expansion valve (1-100) is provided. In the electronic expansion valve (1-100), the bearing (1-23) is arranged between the valve needle (1-22) and the screw (1-31).

Provided are a control method of a heat pump system and a heat pump system. The heat pump system includes a throttling element and a four-way valve. The four-way valve has a first state in a case that the heat pump system operates for refrigerating and a second state in a case that the heat pump system operates for heating. The control method includes that: before the four-way valve is switched from the first state to the second state, A is compared with B, and switching of the state of the four-way valve is controlled and the opening degree of the throttling element is adjusted according to the comparison result, or switching of the state of the four-way valve is controlled according to the comparison result, or the opening degree of the throttling element is adjusted according to the comparison result.

Provided are a control method of a heat pump system and a heat pump system. The heat pump system includes a throttling element and a four-way valve. The four-way valve has a first state in a case that the heat pump system operates for refrigerating and a second state in a case that the heat pump system operates for heating. The control method includes that: before the four-way valve is switched from the first state to the second state, A is compared with B, and switching of the state of the four-way valve is controlled and the opening degree of the throttling element is adjusted according to the comparison result, or switching of the state of the four-way valve is controlled according to the comparison result, or the opening degree of the throttling element is adjusted according to the comparison result.

A refrigeration system, includes a compressor, a condenser (200), a throttle flow path (100), and an evaporator (300) connected in sequence. A non-adjustable main throttle element (110,120) is disposed in the throttle flow path. A bypass flow path (500) is connected to the throttle flow path respectively at the upstream and downstream of the main throttle element, and provided with an adjustable auxiliary throttle element (510) thereon. A liquid level sensor is disposed upstream or downstream of the throttle flow path, and configured to detect the liquid level. A controller is configured to control the opening of the auxiliary throttle element according to a liquid level signal from the liquid level sensor.

A climate-control system includes a first compressor, a second compressor, a first heat exchanger, a second heat exchanger, and a third heat exchanger. The first compressor includes a first inlet and a first outlet. The second compressor is in fluid communication with the first compressor and includes a second inlet (e.g., a suction inlet), a third inlet (e.g., a vapor-injection inlet), a second compression mechanism, and a second outlet. The second and third inlets are fluidly coupled with the second compression mechanism. The second compression mechanism receives working fluid from the first compressor through the third inlet and discharges working fluid through the second outlet of the second compressor. The first and second compressors are in fluid communication with the first, second, and third heat exchangers.

A method for controlling a vapour compression system (1) is disclosed. A mass flow of refrigerant along a part of the refrigerant path is estimated, based on measurements performed by one or more pressure sensors (10, 12, 13) for measuring a refrigerant pressure at selected positions along the refrigerant path and one or more temperature sensors (11, 14) for measuring a refrigerant temperature at selected positions along the refrigerant path. A refrigerant pressure or a refrigerant temperature at a selected position a pressure sensor (10, 12, 13) or temperature sensor (11, 14) along the refrigerant path is derived, based on the estimated mass flow. The vapour compression system (1) is allowed to continue operating, even if a sensor (10, 11, 12, 13, 14) is malfunctioning or unreliable.