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 system and method for increasing the efficiency of natural gas liquefaction processes by using a hybrid cooling system and method. More specifically, a system and method for converting a transcritical precooling refrigeration process to a subcritical process. In one embodiment, the refrigerant is cooled to sub-critical temperature using an economizer. In another embodiment, the refrigerant is cooled to a sub-critical temperature using an auxiliary heat exchanger. Optionally, the economizer or auxiliary heat exchanger can be bypassed when ambient temperatures are sufficiently low to cool the refrigerant to a sub-critical temperature. In another embodiment, the refrigerant is isentropically expanded.

A cooling system is designed to generally allow for one or more compressors to be bypassed when ambient temperatures are low. The system includes a bypass line and valve that opens when ambient temperatures are low and/or when the pressure of the refrigerant in the system is low. In this manner, the refrigerant can flow through the bypass line instead of through one or more compressors. These compressors may then be shut off. To supply any needed pressure to cycle the refrigerant, the system may include a pump that turns on when the bypass line is open. When ambient temperatures are extremely low, thermosiphon may be used to cycle the refrigerant.

Aspects of the present disclosure include a system for turbo-compression cooling. The system may be aboard a marine vessel. The system includes a power cycle and a cooling cycle. The power cycle includes a first working fluid, a waste heat boiler configured to evaporate the working fluid, a turbine, and a condenser. The condenser condenses the working fluid to a saturated or subcooled liquid. The cooling cycle includes a second working fluid, a first compressor configured to increase the pressure of the second working fluid, a condenser configured to condense the second working fluid to a saturated or subcooled liquid after exiting the first compressor, an expansion valve, and an evaporator. The turbine and first compressor are coupled one to the other. The waste heat boiler receives waste heat from engine jacket water and lubricating oil from a ship service generator. The evaporator cools water in a shipboard cooling loop.

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 carbon dioxide refrigerating system and a refrigerating method thereof. A carbon dioxide refrigerating system, comprising a compressor (10), a condenser (11), a liquid storage device (12), and an evaporator (13) connected in sequence; a suction assembly (15) is arranged between the compressor (10) and the condenser (11), the suction assembly (1%) being in communication with the liquid storage device (12) and in communication with a gas-liquid separator (14), the gas-liquid separator (14) being arranged between the condenser (11) and the liquid storage device (12), and the carbon dioxide gas in the liquid storage device (12) or the gas-liquid separator (14) being capable of being sucked back into the pipeline between the compressor (10) and the condenser (11) by means of the suction assembly (15). The refrigerating system can effectively separate gas and liquid, and can also flash evaporate part of the liquid and supercool the carbon dioxide; the flash evaporation-type condenser (11) can achieve a refrigerating effect by means of radiation, and aerosol is formed in the cavity, quickly evaporating and cooling, and thereby increasing the refrigerating efficiency; the refrigerating system has a simple structure, convenient operation, and low installation and maintenance costs.

This ice making machine includes an ice making unit that includes an ice making surface and a cryogen flow channel through which a cryogen for cooling the ice making surface flows; a pump that pressurizes and discharges the cryogen cooled by a heat exchanger; and a control unit that controls a discharge amount of the pump. The cryogen is carbon dioxide, and the control unit controls the pump such that the cryogen is in a gas-liquid mixed state at an outlet of the cryogen flow channel.

A refrigerant cycle system includes a primary-side cycle that circulates a first refrigerant, a secondary-side cycle that circulates a second refrigerant, and a cascade heat exchanger that exchanges heat between the first refrigerant and the second refrigerant. The primary-side cycle includes a primary-side connection pipe. The secondary-side cycle includes a secondary-side connection pipe. The primary-side connection pipe includes a primary-side gas connection pipe and a primary-side liquid connection pipe. The secondary-side connection pipe includes a secondary-side gas connection pipe and a secondary-side liquid connection pipe. The pipe diameter of the secondary-side gas connection pipe is smaller than the pipe diameter of the primary-side gas connection pipe, or the pipe diameter of the secondary-side liquid connection pipe is smaller than the pipe diameter of the primary-side liquid connection pipe.

A fluid handling 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 receiver to receive the first fluid output by the PX. The receiver forms a chamber to separate the first fluid into a first gas and a first liquid. The system further includes a heat exchanger configured to receive the second fluid from the second outlet of the PX and provide the second fluid to the second inlet of the PX.

A cooling system implements various processes to improve efficiency in high ambient temperatures. First, the system can flood one or more low side heat exchangers in the system. Second, the system can direct a portion of vapor refrigerant from a low side heat exchanger to a flash tank rather than to a compressor. Third, the system can transfer heat from refrigerant at a compressor suction to refrigerant at the discharge of a high side heat exchanger.