An apparatus includes an expansion valve, a load, a sensor, an exhaust system, and a controller. The expansion valve cools a refrigerant. The load uses the refrigerant to cool a space. The sensor detects a concentration of the refrigerant in the space. The exhaust system evacuates the refrigerant from the space. The controller determines whether the detected concentration of the refrigerant in the space exceeds a first threshold and in response to a determination that the detected concentration of the refrigerant exceeds the first threshold, closes the expansion valve. The controller also determines whether the detected concentration of the refrigerant in the space exceeds a second threshold and in response to a determination that the detected concentration of the refrigerant exceeds the second threshold, activates the exhaust system.

The present invention is provided with: a turbo compressor that compresses a refrigerant; a condenser that condenses the refrigerant compressed by the turbo compressor; an expansion valve that expands a liquid refrigerant introduced from the condenser; an evaporator that evaporates the refrigerant expanded by the expansion valve; an oil tank that stores a lubricating oil supplied to the turbo compressor; a pressure equalizing pipe that connects the oil tank and the evaporator; and a control unit that controls start-up. The control unit calculates the amount of a refrigerant eluded into the lubricating oil in the oil tank at the time of start-up, and reduces a pressure reduction speed in the oil tank by limiting the opening operation of an IGV when the refrigerant elution amount per prescribed time exceeds a prescribed value.

A method of determining a refrigerant or a composition of refrigerants in a refrigeration system comprising an expansion valve, an evaporator, one or more evaporator fans, a condenser, one or more condenser fans one or more temperature sensors, one or more pressure sensors, a compressor, and a controller for controlling the refrigeration system, the controller comprising a memory, the expansion valve, the evaporator and the compressor being fluidly interconnected in a refrigerant path having refrigerant flowing therein, comprising the steps of: a) Running a test run and read out values from one or more of the sensors; b) Determining a composition by the result of step a; and c) Adjusting the refrigeration system in relation to the composition determined by step b. Also disclosed is a controller for controlling a refrigeration system and a cooling machine in a reefer container.

A refrigeration cycle apparatus includes a circulation path in which a working fluid containing 1,1,2-trifluoroethylene is circulated from a compressor through a condenser, an expansion valve and an evaporator back to the compressor. The refrigeration cycle apparatus includes a composition change detection unit, a composition adjustment unit, and a control unit. The composition change detection unit detects a change of a composition of the working fluid from a steady composition thereof. The composition adjustment unit adjusts the composition of the working fluid. The control unit controls the composition adjustment unit based on a detection result obtained by the composition change detection unit.

A vapor compression system includes a compressor configured to circulate a refrigerant through a refrigerant loop, a sump configured to receive a mixture of lubricant and the refrigerant from the compressor, and a controller having a memory and a processor. The processor is configured to receive a first signal indicative of a temperature of the mixture within the sump, receive a second signal indicative of a pressure of the mixture within the sump, determine a relative amount of the refrigerant in the mixture based on the first signal and the second signal, and output a control signal in response to the relative amount of the refrigerant in the mixture exceeding a threshold value.

Methods and systems for detecting and correcting improper operation of a compressor in a refrigeration system and/or an HVAC system include a component level detection and prevention and a system level detection and prevention. The system level detection and prevention can be a backup or a confirmation of the component level detection and prevention. The component level detection and prevention can detect and prevent improper compressor operation within a predetermined time so that the compressor's operation period in an improper direction can be minimized, thereby minimizing wear and damage to the compressor.

A refrigeration cycle apparatus Including a refrigerant circuit configured to circulate refrigerant to a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger, the compressor being connected to the indoor heat exchanger by a gas extension pipe, the expansion valve being connected to the outdoor heat exchanger by a liquid extension pipe; pressure sensors and temperature sensors to detect an operating state amount of the refrigerant circuit; and a controller to execute refrigerant-leakage detection operation of detecting refrigerant leakage by calculating a refrigerant amount in the refrigerant circuit based on the operating state amount detected by the pressure sensors and the temperature sensors, and comparing the calculated refrigerant amount with a reference refrigerant amount. The controller controls a quality of the refrigerant at an outlet of the liquid extension pipe to be in a range from 0.1 to 0.7 in the refrigerant-leakage detection operation.

A determination device includes a refrigerant circuit, an operation determination unit, and a refrigerant determination unit. The refrigerant circuit is made of a compressor, a condenser, an expansion mechanism, and an evaporator that are circularly connected. In a refrigeration cycle operation in accordance with a quantity of heat required by the condensers or the evaporators, the operation determination unit determines whether the refrigeration cycle operation can be normally carried out or not. Upon determination that the refrigeration cycle operation cannot be normally carried out, the refrigerant determination unit determines whether a refrigerant in the refrigerant circuit is regenerable or not, based on a result of the determination. Thus the determination device is provided by which an effort involved with determination as to whether the refrigerant is regenerable or not can be reduced.

A method for operating a refrigeration system of a motor vehicle, which refrigeration system has a refrigerant, is disclosed. A ratio between a first component of the refrigerant and a second component of the refrigerant is set in accordance with a parameter, in particular an external parameter. An assembly of a refrigeration system of a motor vehicle is also disclosed.

A refrigeration cycle device circulates a refrigerant, which is a zeotropic refrigerant mixture. In a refrigeration cycle, a compressor, a condenser, an expansion valve, and an evaporator are connected by a refrigerant pipe. The refrigeration cycle device calculates a circulation composition value of the refrigerant based on states before and after the refrigerant temperature and the refrigerant pressure change during the operation of the refrigeration cycle, calculates dT for calibrating a second temperature sensor and dP for calibrating a pressure sensor, based on a reference composition value and the circulation composition value of the refrigerant, corrects the value of the temperature of the refrigerant on an outlet side based on dT, corrects the value of the pressure of the refrigerant based on dP, and operates the refrigeration cycle.