A multi-type air conditioning device controls an evaporation temperature and a condensing temperature, depending on required capacity of an indoor unit. The air conditioning device compares a current evaporation temperature or condensing temperature with a reference value, of an evaporation temperature or an condensing temperature, corresponding to a lower limit flow rate, of a gaseous refrigerant, required for refrigerating machine oil not to accumulate in, but to flow through, the gas branch pipes, and calculates an amount of the refrigerating machine oil accumulated in a gas branch pipe which does not satisfy the lower limit flow rate. When the calculated amount exceeds a set amount, the air conditioning device performs oil collecting operation, and controls the oil collecting operation in view of a flow rate of a gaseous refrigerant in gas branch pipes.

A refrigeration system includes an evaporator, a condenser, a compressor, a capillary tube, and an expansion device. The compressor is configured to circulate a refrigerant between the evaporator and the condenser. The capillary tube is configured to receive the refrigerant from the condenser. The expansion device is configured to receive the refrigerant from the capillary tube and provide the refrigerant to the evaporator. The expansion device is adjustable to control a flow of the refrigerant through the capillary tube.

Provided is an air conditioning apparatus. The air conditioning apparatus includes an outdoor unit which includes a compressor and an outdoor heat exchanger and through which a refrigerant is circulated, an indoor unit through which water is circulated, a heat exchanger in which the refrigerant and the water are heat-exchanged with each other, a water tube configured to guide the water circulated through the indoor unit and the heat exchanger, a pump installed in the water tube, and a controller configured to analyze an output signal of the pump so as to calculate a ration of an air layer in the water tube, the controller being configured to control a target supercooling degree or target superheating degree of the heat exchanger according to the calculated ratio of the air layer.

A device for refuelling containers with pressurized gas, comprising a pressurized gas source, a transfer circuit intended to be removably connected to a container, the device comprising a refrigeration system for cooling the gas flowing from the gas source prior to its entering into the container, the refrigeration system comprising a refrigerant cooling loop circuit comprising, arranged in series, a compressor, a condenser section, an expansion valve and an evaporator section, the refrigeration system comprising a cold source in heat exchange with the condenser section and a heat exchanger located in the transfer circuit, the device comprising an electronic controller connected to the expansion valve and configured for controlling cooling power produced by the refrigeration system via the control of the opening of the expansion valve, the device comprising a differential temperature sensor system measuring the difference between the temperature of the refrigerant in the refrigerant cooling loop circuit at the outlet of the heat exchanger and the temperature of the refrigerant in the cooling loop circuit at the inlet of the heat exchanger, the electronic controller being configured for controlling the cooling power produced as a function of this temperature differential.

An electronic expansion valve, a heat exchange system, and a control for controlling an electronic expansion valve. The electronic expansion valve includes: a valve body; a first temperature sensor configured to detect an evaporator temperature T.sub.eva; a second temperature sensor configured to detect a compressor inlet temperature T.sub.suc; a third temperature sensor configured to detect a compressor outlet temperature T.sub.dis; a fourth temperature sensor configured to detect a condenser temperature T.sub.con; and a controller, which is associated with the first temperature sensor, the second temperature sensor, the third temperature sensor and the fourth temperature sensor, and which adjusts an opening degree of the valve body based on temperature signals from the first temperature sensor, the second temperature sensor, the third temperature sensor and the fourth temperature sensor.

Systems and methods for implementing ejector refrigeration cycles with cascaded evaporation stages that utilize a pump to optimize operation of the ejector and eliminate the need for a compressor between the evaporation stages.

There is disclosed heat pump, comprising: an internal heat exchanger configured to transfer heat from refrigerant in a liquid line pathway to refrigerant in a suction line pathway, to superheat the refrigerant upstream of a compressor; and a controller configured to: control an expansion valve to maintain a target superheat of refrigerant at a control location. The target superheat is variable and is determined based on one or more operating conditions of the heat pump. There is also disclosed a method of operating a heat pump and a simulation method to determine a variable superheat.

A cooling system includes a compressor configured to pressurize carbon dioxide to form pressurized carbon dioxide, a mixer configured to generate mixed refrigerant in which the pressurized carbon dioxide and solvent in a liquid state, a depressurization apparatus provided downstream from the mixer and configured to depressurize the mixed refrigerant, a separator configured to separate carbon dioxide in a gas state from the mixed refrigerant, a heat exchanger configured to exchange heat between the mixed refrigerant cooled through depressurization and a fluid to be cooled, and a second heat exchanger configured to cool the carbon dioxide or the mixed refrigerant using vaporized carbon dioxide or the mixed refrigerant.

Systems and methods for implementing ejector refrigeration cycles with cascaded evaporation stages that utilize a pump to optimize operation of the ejector and eliminate the need for a compressor between the evaporation stages.

A method for controlling a vapour compression system, in particular an opening degree of an expansion valve. According to a first control strategy, the expansion valve is closed until the superheat value has increased above a lower threshold superheat value. According to a second control strategy, the expansion valve is kept open until the suction pressure has increased above a lower threshold suction pressure value. In the case of low superheat value as well as low suction pressure, the second control strategy is selected for a limited period of time.