The present disclosure provides a refrigeration device including a circuit having an evaporator, a compressor, a condenser, and an expansion valve orderly connected by a refrigerant flow path. The refrigeration device further includes a first sensor to sense ambient temperature, second sensor to sense evaporator inlet temperature, a microwave module disposed proximal to the evaporator to generate microwaves, and a controller coupled to the first sensor, the second sensor and the microwave module. The controller determines whether a difference in temperature value between the ambient temperature and the evaporator inlet temperature is equal to or greater than a first predetermined temperature value, and initiates operation of the microwave module to heat an inlet of the evaporator when the difference in temperature value between the ambient temperature and the evaporator inlet temperature is equal to or greater than the first predetermined temperature value.

A method for suppressing the blockage of a miniature Joule-Thomson cryocooler based on a photothermal effect includes: determining form and temperature of a trace impurity contained in a working medium of the cryocooler according to an operating condition of the cryocooler, and selecting an optimal wavelength of an electromagnetic wave based on the form and temperature of the impurity and a peak of absorption spectrum of the impurity to electromagnetic waves; estimating, via a prediction model of input power of the electromagnetic wave, an initial value of input power corresponding to the optimal wavelength; and emitting an electromagnetic wave with the power W by a laser capable of generating the optimal wavelength in a direction perpendicular to a passage of a throttle in the cryocooler to eliminate the impurity in the passage of the throttle.

A method of performing a defrost operation in a heating, ventilation and air conditioning (HVAC) system having a first heat exchanger and a second heat exchanger, the method including determining that the defrost operation is needed; determining a capacity for the defrost operation in response to one or more prior defrost operations; beginning the defrost operation at the determined capacity; monitoring a defrost parameter; determining if the defrost parameter indicates a need for increased capacity; and increasing the capacity of the defrost operation when the defrost parameter indicates the need for increased capacity.

A method of performing a defrost operation in a heating, ventilation and air conditioning (HVAC) system having a first heat exchanger and a second heat exchanger, the method including determining that the defrost operation is needed; determining a capacity for the defrost operation in response to one or more prior defrost operations; beginning the defrost operation at the determined capacity; monitoring a defrost parameter; determining if the defrost parameter indicates a need for increased capacity; and increasing the capacity of the defrost operation when the defrost parameter indicates the need for increased capacity.

A refrigeration cycle device includes a flow path switching unit configured to determine whether an outside-air heat absorption unit is required to be defrosted. The flow path switching unit is further configured to: cause a heat medium to circulate separately between a first circulation circuit configured to cause the heat medium to circulate through a heat source and a second circulation circuit configured to cause the heat medium to circulate between an evaporation unit and the outside-air heat absorption unit, when it is determined that the outside-air heat absorption unit is not required to be defrosted; and switch a flow path of the heat medium to cause the heat medium in the first circulation circuit to circulate through the outside-air heat absorption unit, when it is determined that the outside-air heat absorption unit is required to be defrosted.

A method for terminating defrosting of an evaporator (104) is disclosed. The evaporator (104) is part of a vapour compression system (100). The vapour compression system (100) further comprises a compressor unit (101), a heat rejecting heat exchanger (102), and an expansion device (103). The compressor unit (101), the heat rejecting heat exchanger (102), the expansion device (103) and the evaporator (104) are arranged in a refrigerant path, and an air flow is flowing across the evaporator (104). When ice is accumulated on the evaporator (104), the vapour compression system (100) operates in a defrosting mode. At least one temperature sensor (305) monitors a temperature T.sub.air, of air leaving the evaporator (104). A rate of change of T.sub.air is monitored and defrosting is terminated when the rate of change of the temperature, T.sub.air, approaches zero.

A method for terminating defrosting of an evaporator (104) is disclosed. The evaporator (104) is part of a vapour compression system (100). The vapour compression system (100) further comprises a compressor unit (101), a heat rejecting heat exchanger (102), and an expansion device (103). The compressor unit (101), the heat rejecting heat exchanger (102), the expansion device (103) and the evaporator (104) are arranged in a refrigerant path, and an air flow is flowing across the evaporator (104). When ice is accumulated on the evaporator (104), the vapour compression system (100) operates in a defrosting mode. At least one temperature sensor (305) monitors a temperature T.sub.air, of air leaving the evaporator (104). A rate of change of T.sub.air is monitored and defrosting is terminated when the rate of change of the temperature, T.sub.air, approaches zero.

A circulation system of an air conditioner, an air conditioner, and an air conditioner control method. The circulation system of the air conditioner includes a compressor, a first heat exchanger, a second heat exchanger, and a gas-liquid separation assembly. The gas-liquid separation assembly, together with the compressor, the first heat exchanger, and the second heat exchanger, forms a loop; the gas-liquid separation assembly includes two or more gas-liquid separators which are connected in series; the gas-liquid separation assembly is configured to perform gas-liquid separation for refrigerant. Further, two or more-staged gas-liquid separation can be performed for the refrigerant flowing back to the compressor, so that a problem that return oil containing liquid in the compressor can be effectively solved.

A circulation system of an air conditioner, an air conditioner, and an air conditioner control method. The circulation system of the air conditioner includes a compressor, a first heat exchanger, a second heat exchanger, and a gas-liquid separation assembly. The gas-liquid separation assembly, together with the compressor, the first heat exchanger, and the second heat exchanger, forms a loop; the gas-liquid separation assembly includes two or more gas-liquid separators which are connected in series; the gas-liquid separation assembly is configured to perform gas-liquid separation for refrigerant. Further, two or more-staged gas-liquid separation can be performed for the refrigerant flowing back to the compressor, so that a problem that return oil containing liquid in the compressor can be effectively solved.

A continuous heating control system and method, and an air-conditioning device. The system includes a defrosting solenoid valve (1) arranged on a bypass pipeline, wherein one end of the bypass pipeline is connected to an oil separator (2), and the other end of the bypass pipeline is connected to an outdoor heat exchanger (3); and a heating structure which is arranged at the bottom of a gas separator (4) and used for heating the gas separator (4).