Disclosed is a system for detecting a refrigerant leak in a refrigeration system, wherein a system controller is configured to: execute leak test cycles that include executing a first phase (T1-T2) of transferring refrigerant charge to the evaporator, a second phase (T2-T3) of transferring refrigerant charge to the condenser, and a third phase (T3-T4) of transferring refrigerant charge to the evaporator, determine a reference leak detection cycle time (LDCTREF) by determining a time from a beginning of the second phase (T2) in a first test to an end of the third phase (T4) in the first test, and setting LDCTREF to the time, determine a second leak detection cycle time (LDCT2nd) by determining a time from a beginning of the second phase (T2) in the second test to a second end of the third phase (T4) in the second test, and setting LDCT2nd to the time, determine if a refrigerant leak exists, and communicate the determination.

A control method of a refrigerator includes: determining whether a first temperature of a refrigerating compartment satisfies a first temperature condition; based the first temperature satisfying the first temperature condition, determining whether a second temperature of a freezing compartment satisfies a second temperature condition; based on the second temperature satisfying the second temperature condition, determining (i) whether a third temperature of an ice making compartment satisfies a third temperature condition and (ii) whether a driving time for ice making has passed; maintaining operation of a compressor while determining (i) whether the second temperature satisfies the second temperature condition, (ii) whether the third temperature satisfies the third temperature condition, and (iii) whether the driving time has passed; and stopping operation of the compressor based on at least one of (i) a determination that the third temperature satisfies the third temperature condition or (ii) a determination that the driving time has passed.

A vehicle, a refrigerator for a vehicle, and a method for controlling a refrigerator for a vehicle are provided. The method for controlling the refrigerator for the vehicle includes turning on a switch of the refrigerator for the vehicle, measuring a temperature of an interior of the refrigerator for the vehicle a first time, measuring a temperature of the interior of the refrigerator for the vehicle again a second time after a predetermined time has elapsed from the first time, determining a temperature change of the interior of the refrigerator from the first time to the second time, and operating the refrigerator for the vehicle in a quench mode in which the temperature in the interior of the refrigerator is rapidly lowered, unlike a normal mode, if the temperature change in the interior of the refrigerator is in a positive direction.

A cold source unit is connectable to an indoor heat exchanger and is provided for a refrigerant circuit. The cold source unit includes: a compressor; an outdoor heat exchanger having a gas header; an oil return path through which refrigeration oil is returned from the gas header to the compressor; an oil return adjusting unit configured to adjust a flow rate of refrigeration oil flowing through the oil return path; and a controller configured to control the refrigerant circuit. The controller is configured to control the oil return adjusting unit to prevent refrigeration oil from flowing through the oil return path when the compressor is driven at a frequency equal to or higher than a threshold value, and control the oil return adjusting unit to allow the refrigeration oil to flow through the oil return path when the compressor is driven at a frequency lower than the threshold value.

An HVAC system includes a compressor, condenser, and evaporator. A sensor measures a value associated with the refrigerant in the condenser or the evaporator, and a controller is communicatively coupled to the compressor and the sensor. The controller determines, based on an operational history the compressor, that pre-requisite criteria are satisfied for entering a sensor validation mode. After determining the pre-requisite criteria are satisfied, an initial sensor measurement value is determined. Following determining the initial sensor measurement value, the compressor is operated according to a sensor-validation mode. Following operating the compressor according to the sensor-validation mode for at least a minimum time, a current sensor measurement value is determined. The controller determines whether validation criteria are satisfied for the current sensor value. In response to determining that the validation criteria are satisfied, the controller determines that the sensor is validated.

Disclosed is a system for detecting a refrigerant leak in a refrigeration system, wherein a system controller is configured to: execute leak test cycles that include executing a first phase (T1-T2) of transferring refrigerant charge to the evaporator, a second phase (T2-T3) of transferring refrigerant charge to the condenser, and a third phase (T3-T4) of transferring refrigerant charge to the evaporator, determine a reference leak detection cycle time (LDCTREF) by determining a time from a beginning of the second phase (T2) in a first test to an end of the third phase (T4) in the first test, and setting LDCTREF to the time, determine a second leak detection cycle time (LDCT2nd) by determining a time from a beginning of the second phase (T2) in the second test to a second end of the third phase (T4) in the second test, and setting LDCT2nd to the time, determine if a refrigerant leak exists, and communicate the determination.

An air-conditioning apparatus includes a refrigerant circuit in which a compressor, a flow passage switching device, an outdoor heat exchanger, an indoor heat exchanger, a refrigerant container, a first expansion device and a second expansion device connected by pipes, wherein the indoor heat exchanger and the outdoor heat exchanger have inner volumes satisfying a relationship of an inner volume of the indoor heat exchanger<an inner volume of the outdoor heat exchanger, and a controller which, performs control so as to allow the flow passage switching device to switch the flow passage to the heating flow passage and allow an opening degree of the second expansion device to be larger than that of the first expansion device, starts the compressor, performs control so as to allow the opening degrees of the first expansion device and the second expansion device to be initial opening degrees for the cooling operation.

A load balancing method for two compressors. The two compressors are used in a refrigeration system and are driven coaxially by the same driving device. The method comprises the steps of obtaining parameters, determining balance, and controlling start/stop states. The parameters in the step of obtaining parameters are parameters related to the two compressors, such as a compressor suction side flow rate, or exhaust side flow rate, or suction side temperature; the step of determining balance comprises determining, on the basis of the obtained parameters related to the two compressors, whether load is balanced between the two compressors; the step of controlling start/top states comprises controlling the start/stop states of the two compressors according to whether the load is balanced. The method can monitor the load balance state of two compressors that are coaxially driven, thereby effectively avoiding failure of the refrigeration system caused by unbalanced loads of the compressors.

A refrigeration cycle apparatus includes a compressor, an expansion valve, a flow switching device, a heat source side heat exchanger including a first heat source side heat exchanger and a second heat source side heat exchanger connected in parallel, an opening-and-closing valve provided on downstream of the second heat source side heat exchanger through which refrigerant flows during a defrosting operation, and a controller that, when the defrosting operation is performed, controls the flow switching device so that the refrigerant discharged from the compressor flows into the heat source side heat exchanger. The controller switches the opening-and-closing valve from an open state to a closed state when the defrosting operation is started, determines a point in time when defrosting targets to be defrosted are switched, and switches the opening-and-closing valve from the closed state to the open state in accordance with the point in time determined.

A defrost method for a heat pump system includes running the heat pump system in a heating mode to provide heat to an enclosed space and determining if an outdoor temperature is less than an outdoor threshold temperature. Responsive to a determination that the outdoor temperature is below the outdoor threshold temperature, determining if a calibration state has been previously run. Responsive to a determination that the calibration state has not been previously run, running the heat pump system in the calibration state. Responsive to a determination that the calibration state has been previously run, determining if a temperature difference between a temperature of an evaporator coil of the heat pump system and the outdoor temperature exceeds a temperature threshold value. Responsive to a determination that the temperature difference between the evaporator coil and the outdoor temperature is greater than the temperature threshold value, running the heat pump system in a defrost state.