A multistage compression system uses refrigerant and oil. The multistage compression system includes a low-stage compressor that compresses the refrigerant, a high-stage compressor that further compresses the refrigerant compressed by the low-stage compressor, refrigerant pipes that-introduce the refrigerant compressed and discharged by the low-stage compressor into a suction part of the high-stage compressor, a pressure reducing element disposed between the refrigerant pipes, an accumulator disposed between the refrigerant pipes at a downstream side of the pressure reducing element and at an upstream side of the high-stage compressor, and an oil discharge pipe. The oil discharge pipe discharges the oil in the low-stage compressor. The oil discharge pipe connects the low-stage compressor and a portion of the refrigerant pipes. The portion of the refrigerant pipes is on a downstream side of the pressure reducing element and an upstream side of the accumulator.

A refrigeration system includes a gas cooler or a condenser configured to reject first heat from a first fluid that is at a first pressure and that is in a supercritical state or subcritical state. The refrigeration system further includes an evaporator configured to absorb second heat into a second fluid that is at a second pressure that is lower than the first pressure and that is in a liquid state, a vapor state, or a two-phase mixture of liquid and vapor. The refrigeration system further includes a rotary pressure exchanger configured to receive the first fluid from the gas cooler or the condenser, to receive the second fluid from the evaporator, and to exchange pressure, via a rotor of the rotary pressure exchanger, between the first fluid and the second fluid.

Heat pump type heating apparatus capable of performing a continuous dual-stage operation without stopping a high stage side compressor even when a return temperature of a heating medium reaches a prescribed high temperature and, thereby, improving a sense of being insufficiently warmed due to stoppage of the high stage side compressor or a sense of being insufficiently warmed due to execution of frequent defrosting operations. The heat pump type heating apparatus includes an internal heat exchanger (a second internal heat exchanger) that performs heat exchange between a low-temperature refrigerant on a low-pressure side of a low stage side refrigeration circuit and a high-temperature refrigerant on a high-pressure side of a high stage side refrigerant circuit, a bypass pipe bypassing the internal heat exchanger, and flow path control means that controls a refrigerant flow to each of the internal heat exchanger and the bypass pipe.

Provided is a chiller and system that may be utilized in a supercritical fluid chromatography method, wherein a non-polar solvent may replace a portion or all of a polar solvent for the purpose of separating or extracting desired sample molecules from a combined sample/solvent stream. The system may reduce the amount of polar solvent necessary for chromatographic separation and/or extraction of desired samples. The system may incorporate a supercritical fluid chiller, a supercritical fluid pressure-equalizing vessel and a supercritical fluid cyclonic separator. The supercritical fluid chiller allows for efficient and consistent pumping of liquid-phase gases employing off-the-shelf HPLC pumps. The pressure equalizing vessel allows the use of off-the-shelf HPLC column cartridges. The system may further incorporate the use of one or more disposable cartridges containing silica gel or other suitable medium. The system may also utilize an open loop cooling circuit using fluids with a positive Joule-Thomson coefficient.

The present application provides a refrigeration system using a flow of a carbon dioxide refrigerant. The refrigeration system may include a flash tank, a number of temperature suction compressors for a temperature suction cycle, and a flash gas bypass system positioned between the flash tank and the cycle compressors. The flash gas bypass system may include one or more oversized flash gas compressors so as to alternate between the temperature suction cycle and a flash tank suction cycle.

A method and a correspondingly designed device are provided for controlling or regulating a coolant circuit of an air conditioning system, which includes at least one compressor, at least one condenser or gas cooler, and at least one evaporator. A controllable coolant expansion device is connected to the coolant inlet of the evaporator. It is detected when the coolant circuit is under filled with a coolant and, when an under filling of the coolant is detected, the control strategy of the expansion device is changed.

A thermal management system includes a closed dynamic cooling circuit, and a closed first steady-state cooling circuit. Each circuit has its own compressor, heat rejection exchanger, and expansion device. A thermal energy storage (TES) system is configured to receive a dynamic load and thermally couple the dynamic cooling circuit and the first steady-state cooling circuit. The dynamic cooling circuit is configured to cool the TES to fully absorb thermal energy received by the TES when a dynamic thermal load is ON, and the steady-state cooling circuit is configured to cool the TES when the dynamic thermal load is OFF.

Provided is a refrigeration apparatus which can reduce outlet pressure of a refrigerator even in overload conditions and which can improve refrigeration capacity by liquefying a refrigerant in an intermediate cooler. When outlet pressure of a refrigerator 2 is higher than critical pressure, a control apparatus 60 performs control to reduce the opening degree of a decompression electric valve 31 at the upstream side of an intermediate cooler 30. Thereby, the refrigerant is liquefied by gas-liquid separation in the intermediate cooler 30, so that the refrigerator outlet pressure is made less than the critical pressure, and the liquid refrigerant can be sent to a showcase 3. As a result, the specific enthalpy of the refrigerant at the inlet side of main diaphragm means 41 of the showcase 3 can be reduced, and thereby, the cooling effect can be increased.

A method for controlling a vapour compression system (1) is disclosed, the vapour compression system (1) comprising an ejector (5). The method comprises controlling a compressor unit (2) in order to adjust a pressure inside a receiver (6), on the basis of a detected pressure of refrigerant leaving an evaporator (8). The portion of refrigerant leaving the evaporator (8) which is supplied to a secondary inlet (15) of the ejector is maximised and the portion of refrigerant supplied directly to the compressor unit (2) is minimised, while ensuring that the pressure of refrigerant leaving the evaporator (8) does not decrease below an acceptable level.

A system has a compressor, a heat rejection heat exchanger, first and second ejectors, first and second heat absorption heat exchangers, and a separator. The ejectors each have a primary inlet coupled to the heat rejection exchanger to receive refrigerant. A second heat absorption heat exchanger is coupled to the outlet of the second ejector to receive refrigerant. The separator has an inlet coupled to the outlet of the first ejector to receive refrigerant from the first ejector. The separator has a gas outlet coupled to the secondary inlet of the second ejector to deliver refrigerant to the second ejector. The separator has a liquid outlet coupled to the secondary inlet of the first ejector via the first heat absorption heat exchanger to deliver refrigerant to the first ejector.