The invention provides a device for the inductive compression of carbon dioxide via isochoric heating. The resulting hot, supercritical or compressed carbon dioxide is suitable for driving a gas turbine with highly efficient use of the input thermal energy, for local heating and cooling applications, and for pipeline transportation to remote locations where the high enthalpy content of the gas can be harvested.

A refrigeration system, in particular a transport refrigeration system, comprising: a refrigerant circuit, which in particular works using CO.sub.2 as the refrigerant and in which there is guided a total mass flow of the refrigerant; a high-pressure-side heat exchanger arranged in the refrigerant circuit and cooling refrigerant compressed to a high pressure; at least one cooling stage which expands the principal mass flow from the intermediate-pressure collector to a low pressure in at least one cooling expansion member and in so doing makes refrigeration capacity available at a low-pressure-side heat exchanger; and a refrigerant compressor unit which compresses the principal mass flow from a low pressure to a high pressure, wherein the refrigerant compressor unit has a first compressor stage for compressing, to a medium pressure, the refrigerant of the principal mass flow supplied at low pressure, and a second compressor stage for compressing, to a high pressure, the refrigerant of the principal mass flow that has been compressed to a medium pressure.

A system includes a high side heat exchanger, a flash tank, a first load, a second load, and a thermal storage tank. The high side heat exchanger is configured to remove heat from a refrigerant. The flash tank is configured to store the refrigerant from the high side heat exchanger and discharge a flash gas. The first load is configured to use the refrigerant from the flash tank to remove heat from a first space proximate to the first load. The second load is configured to use the refrigerant from the flash tank to remove heat from a second space proximate to the second load. The thermal storage tank is configured, when a power outage is determined to be occurring, to receive at least a portion of the flash gas from the flash tank, and remove heat from the flash gas.

A CO.sub.2 based refrigeration system and a method of operating the CO.sub.2 based refrigeration system. The system includes a condenser configured to transfer heat from a CO.sub.2 refrigerant of the refrigeration system to an air stream. The system also includes an indirect evaporative cooler arranged to cool an ambient air stream without changing its moisture content and to supply the cooled ambient air to the condenser to facilitate the transfer of heat from the CO.sub.2 refrigerant.

Refrigeration systems are described. The systems include a compression device, a heat rejecting heat exchanger, an ejector, and first and second expansion devices with respective heat absorbing heat exchangers. The ejector is arranged to receive refrigerant fluid from the heat rejecting heat exchanger at a high pressure inlet of the ejector. Fluid pathways extend from an outlet of the ejector into a branched flow path to provide flows of refrigerant from the ejector to the first and second expansion devices. The first heat absorbing heat exchanger provides cooling at a first temperature and refrigerant fluid from the outlet of the first heat absorbing heat exchanger is directed to a low pressure inlet of the ejector. The second heat absorbing heat exchanger provides cooling at a second temperature and refrigerant fluid from the outlet of the second heat absorbing heat exchanger is directed to the inlet of the compression device.

A method for controlling a three-way valve that diverts return refrigerant from a first compressor to a second compressor or a third compressor, the second and third compressor in parallel includes obtaining a temperature of the return refrigerant indicating a degree of superheat of the return refrigerant. The method also includes determining if the three-way valve should be transitioned into a first position, transitioned into a second position, or maintained in a current one of the first position or the second position. The method also includes transitioning the three-way valve into the first position or the second position, or maintaining the three-way valve in the first position or the second position. In the first position, the first compressor provides the return refrigerant to the second compressor through the three-way valve and in the second position, the first compressor provides the return refrigerant to the third compressor through the three-way valve.

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.

A cooling system uses P-traps to address the oil return issues that result from a vertical separation between a compressor and a heat exchanger. Generally, the vertical piping that carries the refrigerant from the compressor to the heat exchanger includes P-traps installed at various heights to capture oil in the refrigerant and to prevent that oil from flowing back to the compressor. T-connections are coupled to the P-traps to allow the oil to drain out of the P-traps. The oil may then be collected and returned to the compressor.

A cooling system uses P-traps to address the oil return issues that result from a vertical separation between the compressor and the high side heat exchanger. Generally, the vertical piping that carries the refrigerant from the compressor to the high side heat exchanger includes P-traps installed at various heights to capture oil in the refrigerant and to prevent that oil from flowing back to the compressor. As oil collects in the P-traps, the refrigerant begins to push the oil upwards until the oil reaches the high side heat exchanger. Multiple piping of different sizes may be used depending on a discharge pressure of the compressor. When the discharge pressure is higher, a larger piping may be used direct the oil and refrigerant to the high side heat exchanger.

A system includes a pressure exchanger (PX) configured to receive a first fluid at a first pressure and a second fluid at a second pressure and exchange pressure between the first fluid and the second fluid. The system further includes a condenser configured to provide corresponding thermal energy from the first fluid to a corresponding environment. The system further includes a first ejector to receive a first gas and increase pressure of the first gas to form the second fluid at the second pressure. The first ejector is further to provide the second fluid at the second pressure to the PX.