A method for conditioning a fluid in a temperature-insulated test space and a test space of a test chamber for receiving test materials. A cascading cooling device creates a particular temperature range within the test space, and the cooling device has a first cooling circuit including a cascading heat exchanger, a first compressor, a condenser and a first expanding element, and a second cooling circuit including a heat exchanger, a second compressor, the cascading heat exchanger and a second expanding element The cascading heat exchanger is cooled by the first cooling circuit, the heat exchanger is cooled by a bypass passing through the heat exchanger and bridging the cascading heat exchanger, the first compressor is turned off, and a first refrigerant is conducted and condensed in a gaseous state in the cascading heat exchanger on a low-pressure side of the bypass.

A cooling device includes a plurality of evaporators thermally coupled to a plurality of heat generating devices, respectively, a condenser coupled to the plurality of evaporators through a gas-phase pipe, a first tank coupled to the condenser through a liquid-phase pipe and configured to store a refrigerant therein, a second tank disposed at a position higher than the plurality of evaporators and configured to store the refrigerant therein, a plurality of distribution pipes each through which a corresponding evaporator of the plurality of evaporators is coupled to the second tank, a pump coupled to the first tank and the second tank through coupling pipes, respectively, and a bypass pipe through which the second tank is coupled to one of the first tank and the liquid-phase pipe.

A method of operating a refrigeration cycle apparatus uses a compressor to compress a coolant. The compressed coolant is fed to a condenser for release of heat, the condensed coolant is later fed to a primary side of an internal heat exchanger for release of heat, and the cooled coolant is guided through an expansion device. The coolant expanded in the expansion device is fed to an evaporator for absorption of heat, the evaporated coolant is later fed to a secondary side of the internal heat exchanger for absorption of heat, and the heated coolant is fed to the compressor. For suction gas temperature control, an amount of heat transferred from the primary side to the secondary side of the internal heat exchanger is controlled with the aid of an additional expansion device arranged parallel to the heat exchanger and between the condenser and the evaporator.

A refrigeration system including one or more first compressor(s) for compressing a carbon dioxide (CO.sub.2) refrigerant, a main heat rejection system for cooling the CO.sub.2 refrigerant, one or more high pressure expansion device(s) for reducing the pressure of the CO.sub.2 refrigerant, a receiver for storing the CO.sub.2 refrigerant, one or more high pressure expansion device(s), an evaporator and a receiver pressure regulating device. The refrigeration system further includes an auxiliary refrigeration system including an auxiliary compressor arranged to compress at least part of the CO.sub.2 refrigerant and thereafter to direct the compressed CO.sub.2 refrigerant to a heat rejection system.

A cooling system includes a heat exchanger through which a refrigerant flows, the heat exchanger having a fluid passing therethrough such that heat is rejected to the fluid, an evaporator, a refrigerant piping split point that receives the refrigerant at a given pressure from the heat exchanger and splits the refrigerant flow into a first circuit and a second circuit, the first circuit having an expansion valve that receives the refrigerant at the given pressure, and the second circuit having a first turbine coupled to a first compressor, wherein the first turbine receives the refrigerant at the given pressure, and a set of valves arranged to direct the refrigerant through the first circuit, the second circuit, or both the first and second circuits based on ambient conditions of the cooling system.

Disclosed in the present invention are a zero-load output non-stop control method and apparatus, and a unit. The apparatus comprises: a three-way valve, provided at an exhaust port of a compressor; a mixing tank, provided between an air suction port of the compressor and a condenser and used for mixing a refrigerant discharged by the compressor with a refrigerant throttled by the condenser; a first electronic expansion valve, provided on a first pipeline from the condenser to the mixing tank and sued for controlling the amount of the refrigerant throttled by the condenser and entering the mixing tank; and an electromagnetic valve, provided on a second pipeline between the three-way valve and the mixing tank and used for controlling the amount of the refrigerant discharged by the compressor and directly entering the mixing tank.

The present invention aims to alleviate the risk of leakage of refrigerant from a refrigerant circuit and particularly at the utilization side of the refrigerant circuit without the need to provide a dedicated bypass for refrigerant leakage prevention. A refrigerant system is configured such that, when a refrigerant leakage detection sensor detects refrigerant leakage, a controller is configured to adjust a opening degree of a bypass expansion valve independently of a pressure and/or temperature value detected by a sensor. A method of controlling a refrigerant system is also provided.

A method for managing a thermal management device for a motor vehicle is disclosed. The device has a refrigerant circuit that circulates a refrigerant fluid. The circuit includes a main loop having, in the direction of circulation of the fluid, a compressor, a condenser configured to exchange heat energy with a first element, a first expansion device and a first evaporator configured to exchange heat energy with a second element. The device operates in a mode of strict cooling of the third element in which the condenser transfers heat energy to the first element and only the second evaporator absorbs heat energy from the third element. The method includes managing the open diameter of the first expansion device as a function of the ambient temperature so that the refrigerant fluid circulates inside the first evaporator, the open diameter of the first expansion device decreasing as the ambient temperature of the first element increases.

A refrigeration cycle device includes a compressor, a heater device, a high-stage side decompressor, a gas-liquid separator, a refrigerant branch portion, a first decompressor, a first evaporator, a second decompressor, and a second evaporator. The compressor has an intermediate pressure port through which an intermediate-pressure refrigerant flows into the compressor. The gas-liquid separator is configured to separate the intermediate-pressure refrigerant into a gas refrigerant and a liquid refrigerant. The refrigerant branch portion is configured to divide a flow of the liquid refrigerant separated by the gas-liquid separator. In a cooling mode for cooling a heat exchange target fluid, a refrigerant circuit is switched such that a low-pressure refrigerant flows from the branch portion to the first evaporator. In a heating mode for heating the heat exchange target fluid, the refrigerant circuit is switched such that the low-pressure refrigerant flows from the branch portion to the second evaporator.

A refrigerant for a cooling device comprising a cooling circuit with at least one heat exchanger, the refrigerant undergoing a phase transition in the heat exchanger, the refrigerant being a refrigerant mixture composed of a mass fraction of carbon dioxide (CO.sub.2), a mass fraction of pentafluoroethane (C.sub.2HF.sub.5) and a mass fraction of at least one other component, wherein the mass fraction of carbon dioxide in the refrigerant mixture is up to 60 mass percent, the mass fraction of pentafluoroethane being 11 to 72 mass percent, the other component being 2,3,3,3-tetrafluoropropene (C.sub.3H.sub.2F.sub.4), the mass fraction of 2,3,3,3-tetrafluoropropene being up to 51 mass percent.