A dehumidifier with a pre-cooling device includes a compressor, a condenser, an expansion device, a microchannel pre-cooler and an evaporator assembly. During operation, moist air enters from an air inlet of the dehumidifier, and passes through the microchannel pre-cooler to make the moist air to reach a saturated steam state and passes through the evaporator assembly for heat exchange to condense and dehumidify the moist air, and the dehumidified air passes through the condenser for heating and finally discharged from the air outlet, so that the water vapor in the moist air can be condensed into a liquid better to improve the condensation and dehumidification effects of the evaporator and reduce the air humidity effectively, so as to improve the dehumidification effect of the equipment.

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.

Provided is a heat pump system having a compressor, a liquid-side on-off valve, a gas-side on-off valve, and a controller. The controller is configured to perform a refrigerant recovery operation for recovering refrigerant from a utilization-side piping section to a heatsource-side piping section by operating the compressor while the liquid-side on-off valve is closed and the gas-side on-off valve is open, and control the system such that the gas-side on-off valve starts closing when a predetermined valve-close condition is satisfied during the compressor is operating for recovering refrigerant, and such that the operation of the compressor for recovering refrigerant stops after the closing of the gas-side on-off valve started.

A heat exchanger system is provided with at least one heat exchanger for heating the suction gas between the evaporator and the compressor inlet, which heat exchanger is heated by the refrigerant liquid. It is the object to achieve dry suction gas from a flooded evaporator. It is an object to achieve heat exchange with a minimum flow restriction. The objects can be fulfilled by a heat exchanger including a circulating path for the suction gas and for the refrigerant liquid. Hereby it can be achieved that the circulating path forms a highly effective heat exchanger. The circulating path can be achieved with a very large heat-transmitting surface. The circulation of the suction gas will force liquid particles in the suction gas to be forced outside in the circulating path and in that way come in direct thermal contact with the surface that separates the suction gas from the refrigerant liquid.

A fuel cooling system includes a refrigeration unit configured to circulate a refrigerant, a bypass cooling circuit (132) fluidly coupled to the refrigeration unit, and a power generation system operably coupled to the refrigeration unit. The power generation system includes a fuel tank (34) fluidly coupled to an engine (32), and a fuel cooling circuit (160) is fluidly coupled between the fuel tank and the engine. The fuel cooling circuit is thermally coupled to the bypass cooling circuit and is configured to cool a fuel by thermal exchange with the refrigerant.

A fuel cooling system includes a refrigeration unit configured to circulate a refrigerant, a bypass cooling circuit (132) fluidly coupled to the refrigeration unit, and a power generation system operably coupled to the refrigeration unit. The power generation system includes a fuel tank (34) fluidly coupled to an engine (32), and a fuel cooling circuit (160) is fluidly coupled between the fuel tank and the engine. The fuel cooling circuit is thermally coupled to the bypass cooling circuit and is configured to cool a fuel by thermal exchange with the refrigerant.

A gas injection-type heat-management system includes a base flow path sequentially provided with a compressor, an inner condenser, a heat exchanger, a first expansion valve, an outer condenser, a second expansion valve, and an evaporator, a heat exchange flow path branched from the base flow path at an upstream point of the heat exchanger, disposed to be heat-exchangeable with the base flow path in the heat exchanger by passing through a third expansion valve, and joined to the base flow path on the compressor or at an upstream point thereof, a first bypass flow path connected to the base flow path, a second bypass flow path connected to the base flow path, and a recirculation flow path branched from the base flow path at a downstream point of the outer condenser and joined to the heat exchange flow path at an upstream point of the third expansion valve.

Systems and methods for controlled subcooling of working fluid in a heating, ventilation, air conditioning and refrigeration (HVACR) system through a suction line heat exchanger are disclosed. The suction line heat exchanger may receive a first fluid flow travelling to a suction of the compressor in the HVACR system and second flow of working fluid that is travelling from a heat exchanger receiving the discharge of the compressor to an expansion device. Superheating of the first working fluid may be determined based on temperature measurements prior to and following the suction line heat exchanger. The superheating may be used to control the quantity of the second flow of working fluid introduced into the suction line heat exchanger, for example to maintain superheat that is below a threshold value. These systems may include chillers and heat pump systems, and methods may be applied to chillers or heat pump systems.

Systems and methods for controlled subcooling of working fluid in a heating, ventilation, air conditioning and refrigeration (HVACR) system through a suction line heat exchanger are disclosed. The suction line heat exchanger may receive a first fluid flow travelling to a suction of the compressor in the HVACR system and second flow of working fluid that is travelling from a heat exchanger receiving the discharge of the compressor to an expansion device. Superheating of the first working fluid may be determined based on temperature measurements prior to and following the suction line heat exchanger. The superheating may be used to control the quantity of the second flow of working fluid introduced into the suction line heat exchanger, for example to maintain superheat that is below a threshold value. These systems may include chillers and heat pump systems, and methods may be applied to chillers or heat pump systems.

The heat source controller transmits the drive permission signal (SE) to the utilization controller when the compression element is drivable. The utilization controller opens a utilization expansion valve when heat exchange in a utilization heat exchanger is required, on condition that the utilization controller receive the drive permission signal (SE).