A vapor compression refrigeration system has a main refrigerant circuit having a primary compressor group, a gas cooler or condenser, an expansion device, a liquid receiver, and at least one evaporator. An emergency circulation duct fluidically connects the liquid receiver to the main circuit to allow a flow of refrigerant from the liquid receiver to the gas cooler. An emergency compressor group in the emergency circulation duct is activatable when pressure inside the liquid receiver or in the duct upstream of the emergency compressor group meets or exceeds a predefined emergency pressure threshold. An uninterruptible power supply powers the emergency compressor group and expansion device during a shutdown of the refrigeration system. When pressure inside the liquid receiver or in the duct upstream of the emergency compressor group equals or exceeds the predefined emergency pressure threshold, an emergency circulation of refrigerant fluid is activated through the emergency circulation duct.

A refrigerant vapor compression system comprising a plurality of components connected in a refrigerant flow circuit by a plurality of refrigerant lines, said components including: a compression device; a refrigerant heat rejection heat exchanger; a first expansion device; a refrigerant heat absorption heat exchanger; and a flash tank system having a first flash tank operably coupled to a second flash tank by a first connection, the flash tank system being disposed in the refrigerant flow circuit between the refrigerant heat rejection heat exchanger and the refrigerant heat absorption heat exchanger.

A temperature control system includes: first and second refrigerator units; a first fluid flow apparatus that allows a first fluid to flow therethrough and that is cooled by the first refrigerator unit; a second fluid flow apparatus that allows a second fluid to flow therethrough and that is cooled by the second refrigerator unit; and a valve unit that is configured to allow the first fluid or the second fluid to selectively flow out therefrom. The first refrigerator unit has, in a medium-temperature-side refrigerator, a medium-temperature-side first expansion valve and a medium-temperature-side second expansion valve. A medium-temperature-side second evaporator corresponding to the medium-temperature-side second expansion valve and a low-temperature-side condenser of a low-temperature-side refrigerator constitute a cascade condenser. The first fluid is cooled by a medium-temperature-side first evaporator corresponding to the medium-temperature-side first expansion valve, and is then cooled by a low-temperature-side evaporator of the low-temperature-side refrigerator.

A heat pump system that can be selectively utilized to discharge excessive heating and cooling capacity toward secondary devices of the system to maintain operation of the heat pump system to better manage the respective temperatures associated with the fluid flows in a manner that reduces the need for cycling the heat pump system ON and OFF to attain desired fluid output temperature manipulations.

A packaged, pumped liquid, evaporative-condensing recirculating ammonia refrigeration system with charges of 10 lbs or less of refrigerant per ton of refrigeration capacity. The compressor and related components are situated inside the plenum of a standard evaporative condenser unit, and the evaporator is close coupled to the evaporative condenser. Single or dual phase cyclonic separators may also be housed in the plenum of the evaporative condenser.

An air conditioning apparatus includes: a supercooling heat exchanger configured to supercool refrigerant flowing in a first flow path between an outdoor heat exchanger and an expansion valve; a flow path switching valve configured to switch a flow path between an indoor heat exchanger and a compressor to one of a second flow path that does not extend through the supercooling heat exchanger and a third flow path that extends through the supercooling heat exchanger; a bypass circuit that is branched from the first flow path and extends through the supercooling heat exchanger; and a bypass regulating valve provided in the bypass circuit; and a controller. In a cooling operation, when a load is not low, the controller selects the second flow path and opens the bypass regulating valve, whereas when the load is low, the controller selects the third flow path and closes the bypass regulating valve.

An apparatus includes a high side heat exchanger, a flash tank, a first load, a first compressor, an auxiliary cooling system, and a first check valve. The high side heat exchanger removes heat from a refrigerant. The flash tank stores the refrigerant from the high side heat exchanger. The first load uses the refrigerant to remove heat from a space proximate the first load. The first compressor compresses the refrigerant from the first load. The auxiliary cooling system removes heat from the refrigerant stored in the flash tank during a power outage. The first check valve directs the refrigerant between the first load and the first compressor back to the flash tank when the pressure of the refrigerant between the first load and the first compressor exceeds a threshold during the power outage.

The refrigeration cycle device includes a compressor, an outside heat exchanger, a cooling pressure reducing unit, an evaporator, a branch portion, a cool down pressure reducing unit, a temperature adjusting unit, a merging portion, a bypass passage, and a first on-off valve. The temperature adjusting unit includes a temperature adjusting heat exchange unit and adjusts a temperature of a temperature adjustment target object. During a cooling and cool down mode, the outside heat exchanger functions as a radiator, and the evaporator and the temperature adjusting heat exchange unit function as heat absorbers. During a target object warm up mode, the refrigerant discharged from the compressor is guided to the temperature adjusting heat exchange unit via the bypass passage, and the heat of the discharged refrigerant is used as a heat source for heating the temperature adjustment target object.

A cooling system drains oil from low side heat exchangers to vessels and then uses compressed refrigerant to push the oil in the vessels back towards a compressor. Generally, the cooling system operates in three different modes of operation: a normal mode, an oil drain mode, and an oil return mode. During the normal mode, a primary refrigerant is cycled to cool one or more secondary refrigerants. As the primary refrigerant is cycled, oil from a compressor may mix with the primary refrigerant and become stuck in a low side heat exchanger. During the oil drain mode, the oil in the low side heat exchanger is allowed to drain into a vessel. During the oil return mode, compressed refrigerant is directed to the vessel to push the oil in the vessel back towards a compressor.

An efficient air conditioning system absorbs heat via a fluid, such as a refrigerant, from one place in the cycle and rejects the heat from the fluid in another place in the cycle. A receiver or storage tank is arranged between the condenser and the first heat exchanger to ensure a constant and steady flow of fluid to the heat exchanger. A dual heat exchanger system and additional expansion valve provide sub-cooling of the liquid refrigerant exiting the condenser.