A cooling system includes a second receiver that receives refrigerant from a low side heat exchanger. A pipe connects the second receiver to a first receiver. A vapor portion of the refrigerant in the first receiver can flow through the pipe to the second receiver. A compressor is used to create a pressure differential in the second receiver relative to the first receiver such that the pressure in the first receiver is greater than the pressure in the second receiver. This pressure differential effectively acts as a pump that pushes the liquid refrigerant in the first receiver towards the low side heat exchanger.

An integrated system floods an air conditioning low side heat exchanger such that the air conditioning low side heat exchanger does not evaporate all the liquid refrigerant entering the air conditioning low side heat exchanger. As a result, both liquid and vapor refrigerant leave the air conditioning low side heat exchanger. The system includes an additional receiver that stores the refrigerant leaving the air conditioning low side heat exchanger. To prevent the liquid refrigerant in the receiver from overflowing, the liquid refrigerant in the receiver is used in a refrigeration system when the level of liquid refrigerant in the receiver exceeds a threshold (e.g., as detected by a sensor in the receiver).

A dynamic receiver is included in parallel to an expander of a heating, ventilation, air conditioning, and refrigeration (HVACR) system. The dynamic receiver allows control of the refrigerant charge of the HVACR system to respond to different operating conditions. The dynamic receiver can be filled or emptied in response to the subcooling observed in the HVACR system compared to desired subcooling for various operating modes. The HVACR system can include a line directly conveying working fluid from compressor discharge to the dynamic receiver to allow emptying of the dynamic receiver to be assisted by injection of the compressor discharge.

A transcritical R-744 refrigeration system, especially used for refrigerating a skating rink, has a heat exchanger between the gas cooler followed by a throttling device and the flash tank (or receiver), in order to eliminate the need of a flash-gas bypass. The heat exchanger connects to an external mechanical refrigeration system operating at a higher evaporating temperature than the transcritical R-744 refrigeration system, and generally totally condenses the vapor of the R-744 refrigerant before it reaches the flask tank. A method for improving the energy efficiency of the transcritical R-744 refrigeration system is also disclosed.

An air conditioner may prevent a refrigerant stored in a refrigerant storage from rapidly flowing into a main refrigerant circuit when the type of operation is switched.

The air conditioner may include a refrigerant circuit provided with a compressor, a condenser, an expansion valve and an evaporator; a refrigerant amount detection device configured to determine whether a refrigerant state in an outlet of the compressor is a supercooled state or a gas-liquid two phase state, and configured to calculate a refrigerant amount ratio in the refrigerant circuit, based on a predetermined set value according to at least one of a temperature and a pressure detected in the refrigerant circuit, and the refrigerant state; and a controller configured to control the refrigerant circuit according to the refrigerant amount ratio calculated by the refrigerant amount detection device.

A hybrid air handler cooling unit has a bi-modal heat exchanger. In a direct expansion mode or a pumped refrigerant economization mode, the bi-modal heat exchanger is in a refrigerant path in parallel with first and second condenser coils and functions as a condenser coil. In a mixed direct expansion/pumped refrigerant economization mode, the bi-modal heat exchanger is in a refrigerant path in series between an outlet of a pump and an inlet of the first condenser coil and functions as a pre-cooler evaporator coil with return air first flowing across the bi-modal heat exchanger and then across an evaporator coil of an evaporator.

An accumulator, including a housing and a cover body, one end of the housing being open; the housing is internally provided with an accommodating cavity, the accommodating cavity being internally provided with a filter; a peripheral wall of the housing comprises a first thick wall part, the first thick wall part being provided with an inlet channel, and one end of the inlet channel communicating with the accommodating cavity, while the other end of the inlet channel communicates with the outside; one end of an outlet channel communicates with the accommodating cavity by means of the filter, while the other end of the outlet channel communicates with an outer portion of the housing. The accumulator may be directly welded and fixed to a heat exchange core without requiring a pipeline connection, the risk of external leakage being small, and the anti-seismic performance being high.

A refrigeration system includes: a compressor arrangement for compressing gaseous refrigerant from a first pressure to a second pressure, wherein the second pressure comprises a condensing pressure; a plurality of condenser evaporator systems, wherein each condenser evaporator system comprises: a condenser for receiving gaseous refrigerant at a condensing pressure and condensing the refrigerant to a liquid refrigerant; a controlled pressure receiver for holding the liquid refrigerant from the condenser; and an evaporator for evaporating liquid refrigerant from the controlled pressure receiver to form gaseous refrigerant; a first gaseous refrigerant feed line for feeding the gaseous refrigerant at the second pressure from the compressor arrangement to the plurality of condenser evaporator systems; and a second gaseous refrigerant feed line for feeding gaseous refrigerant from the plurality of condenser evaporator systems to the compressor arrangement.

A dynamic receiver is included in parallel to an expander of a heating, ventilation, air conditioning, and refrigeration (HVACR) system. The dynamic receiver allows control of the refrigerant charge of the HVACR system to respond to different operating conditions. The dynamic receiver can be filled or emptied in response to the subcooling observed in the HVACR system compared to desired subcooling for various operating modes. The HVACR system can include a line directly conveying working fluid from compressor discharge to the dynamic receiver to allow emptying of the dynamic receiver to be assisted by injection of the compressor discharge.

A cooling device includes a plurality of evaporators thermally coupled to a plurality of heat generating devices, respectively, a condenser coupled to the plurality of evaporators through a gas-phase pipe, a first tank coupled to the condenser through a liquid-phase pipe and configured to store a refrigerant therein, a second tank disposed at a position higher than the plurality of evaporators and configured to store the refrigerant therein, a plurality of distribution pipes each through which a corresponding evaporator of the plurality of evaporators is coupled to the second tank, a pump coupled to the first tank and the second tank through coupling pipes, respectively, and a bypass pipe through which the second tank is coupled to one of the first tank and the liquid-phase pipe.