Methods for shortening the cycle time in each of the defrost, standby and cool modes of operation of a very low temperature refrigeration system. These methods can be used alone or in combination with one or more of each of the other techniques, including, for example, in a single very low temperature refrigeration system, to provide a fast total cycle of one, two or all three of the defrost, standby and cool modes.

The present disclosure relates to a refrigeration circuit that includes a controller communicatively coupled to a compressor, an expansion valve, and a sensor of the refrigeration circuit. The controller may activate the compressor and actuate the expansion valve such that the compressor is active while the expansion valve is closed. The controller may also measure a pressure of a refrigerant in the refrigeration circuit using the sensor while the compressor is active and the expansion valve is closed. Additionally, the controller may determine whether a refrigerant leak exists based on a maximum measurement time being reached or a time difference between a first time associated with the compressor being active while the expansion valve is closed and a second time associated with the measured pressure falling below a threshold value.

Provided is an air-conditioning device that includes an outdoor unit and an indoor unit, the outdoor unit including a compressor, the indoor unit being connected to the outdoor unit, the air-conditioning device including a heating means provided to the compressor, and configured to heat refrigerant in the compressor, and a controller configured to control the heating means. The controller includes a heat load learning unit configured to learn a heat load based on temperature data and air conditioning data, a stagnation prevention control start timing estimation unit configured to estimate a stagnation prevention control start timing based on the heat load obtained by learning, the stagnation prevention control start timing being a timing at which a stagnation prevention control of heating the compressor is started, and a device control unit configured to control the heating means such that the stagnation prevention control is performed by the heating means at the stagnation prevention control start timing estimated.

An HVAC system includes a pressure sensor is disposed in a suction line between a compressor and an indoor heat-exchange coil. The pressure sensor is electrically coupled to a compressor controller. An HVAC controller is electrically coupled to the compressor controller. The HVAC controller is configured to transmit a signal to the compressor controller to activate and de-activate the compressor. The compressor controller is configured to receive a signal from the HVAC controller to activate the compressor, determine a start speed of the compressor, monitor a run time of the compressor, and modulate a speed of the compressor.

Disclosed is a refrigerating and freezing device, including a cabinet defining at least one storage compartment, at least one cabinet door configured to respectively open and close the at least one storage compartment, a refrigerating system configured to provide cooling capacity to the at least one storage compartment, and a heating unit. The heating unit includes a cylinder body disposed in one storage compartment and provided with a pick-and-place opening, a door body configured to open and close the pick-and-place opening, and an electromagnetic generating system configured to generate electromagnetic waves in the cylinder body to heat an object to be processed. The refrigerating and freezing device further includes a cabinet door detection device, and the cabinet door detection device is configured to detect open and closed states of the cabinet door corresponding to the storage compartment provided with the cylinder body; and the electromagnetic generating system stops generating electromagnetic waves when a corresponding cabinet door is in an open state, which can prevent electromagnetic waves in the heating unit from leaking and affecting the health of a user, thereby improving the safety of the refrigerating and freezing device.

A refrigerator and a control method, device and system thereof are provided. The method comprises detecting and confirming that the cumulative running time of a compressor is no less than a running time threshold, and an ice maker is currently in a working state, and controlling the ice maker to perform an defrosting operation after a current ice making period is ended, the running time threshold being a time difference between the defrosting period of the refrigerator and the ice making period of the ice maker. The method allows avoiding defrosting in the ice making period, and therefore, the influence of defrosting on ice making of the ice maker can be reduced, the ice making efficiency and the ice making capacity if the ice maker can be effectively promoted, the ice making period is shortened, energy consumption is reduced, and produce reliability is improved.

In a method for operating a compressor (22) having an inlet (26) and an outlet (28), the method includes: running the compressor to compress a fluid; shutting down (422) the compressor; determining (420) a condition-dependent threshold restart pressure difference (threshold) across the compressor; relieving the pressure difference to reach the threshold; and, after the threshold is reached, restarting (434) the compressor.

A controller within a refrigeration application controls temperature and humidity within a compartment of the refrigeration application. The controller may begin cooling the compartment based on a measured temperature value for the compartment. The controller may delay a starting time of an evaporator fan within the compartment based at least in part on a measured humidity value for the compartment. The controller may also adjust an operating time of a condenser fan based at least in part on the measured humidity value.

A defogging control system includes a plurality of first heating wires, a plurality of second heating wires, an electrical sensor and driver, a timer, an environment sensing module, and a control module. The electrical sensor and driver is utilized to generate a start signal or a stop signal, corresponding to a controller of a refrigeration storage apparatus. The timer is utilized to count a real-time operation time and record a previous operation time. The environment sensing module is utilized to sense a temperature and a humidity. The control module is utilized to control the first heating wires and the second heating wires by the real-time operation time, the previous operation time, the temperature, and the humidity. Further, a defogging control method is also provided.

A method of controlling a refrigeration system including a medium temperature refrigeration load and a low temperature refrigeration load. The method includes selectively bypassing refrigerant between a medium temperature suction group and a low temperature suction group via a bypass line using an electronic valve positioned in the bypass line. The method also includes controlling flow of refrigerant between the medium temperature suction group and the low temperature suction group via a controller communicatively coupled to the valve, and modulating the valve at any position between a closed position and a full open position to vary an amount of refrigerant flow between the medium temperature suction group and the low temperature suction group in response to determining, via the controller, one or both of a state of the medium temperature suction group and a state of the low temperature suction group.