There is disclosed a reversible heat pump system 100 and a method of operating a reversible heat pump system to control the temperature of a process fluid of a chiller system 500. In a cooling mode, a working fluid is circulated for co-current flow with a process fluid at a heat exchanger 104 functioning as an evaporator heat exchanger, whereas in a heating mode, the working fluid is circulated for counter-current flow with the process fluid at the same heat exchanger 104 functioning as a condenser heat exchanger.

There is disclosed a reversible heat pump system 100 and a method of operating a reversible heat pump system to control the temperature of a process fluid of a chiller system 500. In a cooling mode, a working fluid is circulated for co-current flow with a process fluid at a heat exchanger 104 functioning as an evaporator heat exchanger, whereas in a heating mode, the working fluid is circulated for counter-current flow with the process fluid at the same heat exchanger 104 functioning as a condenser heat exchanger.

A chiller system is provided including a vapor compression circuit consisting of a fluidly coupled compressor, condenser, expansion valve, and evaporator. A refrigerant circulates through the vapor compression circuit. The evaporator is a direct exchange heat exchanger. Refrigerant provided at an outlet of the evaporator is a two-phase mixture including liquid refrigerant and vapor refrigerant. The vapor refrigerant comprises less than or equal to 85% of the two-phase mixture. A refrigerant to refrigerant heat exchanger is fluidly coupled to the circuit. The refrigerant to refrigerant heat exchanger is configured to convert the vapor refrigerant provided at the outlet of the evaporator into a superheated vapor.

A chiller system is provided including a vapor compression circuit consisting of a fluidly coupled compressor, condenser, expansion valve, and evaporator. A refrigerant circulates through the vapor compression circuit. The evaporator is a direct exchange heat exchanger. Refrigerant provided at an outlet of the evaporator is a two-phase mixture including liquid refrigerant and vapor refrigerant. The vapor refrigerant comprises less than or equal to 85% of the two-phase mixture. A refrigerant to refrigerant heat exchanger is fluidly coupled to the circuit. The refrigerant to refrigerant heat exchanger is configured to convert the vapor refrigerant provided at the outlet of the evaporator into a superheated vapor.

An air conditioning system and a method for controlling the same are provided. The air conditioning system includes an enhanced vapor injection compressor, first and second direction switching assemblies, first and second heat exchangers and a flash evaporator. The enhanced vapor injection compressor has an air discharge port, an air supplement port, first and second air suction ports, and an air return port. Pressure in a sliding vane chamber of an air cylinder corresponding to the second air suction port is equal to a discharge pressure at the air discharge port. A first pipe port of the first direction switching assembly is connected with the second air suction port, a second pipe port thereof is connected with the air discharge port and a third pipe port thereof is connected with the liquid accumulator, and the first pipe port is communicated with one of the second and third pipe ports.

A refrigerant circuit includes a compressor operable to compress a refrigerant, an expansion valve, an outdoor heat exchanger, an indoor heat exchanger in a fresh air inlet to a conditioned space, a recovery heat exchanger in an extracted air outlet from the conditioned space, and a reversing valve operable to direct a direction of refrigerant flow between a cooling mode and a heating mode.

Refrigerant is caused to be in a superheating state without impairing the performance of a cascade heat exchanger. A refrigerant cycle system includes a first refrigerant circuit, a second refrigerant circuit, and a first cascade heat exchanger. The first cascade heat exchanger exchanges heat between a first refrigerant that flows in the first refrigerant circuit and a second refrigerant that flows in the second refrigerant circuit. The refrigerant cycle system includes a switching mechanism. The switching mechanism switches a flow path of a refrigerant of at least either one of the first refrigerant circuit and the second refrigerant circuit. The first cascade heat exchanger includes a first main heat exchanging unit acid a first sub heat exchanging unit. The first sub heat exchanging unit is configured to cause the first refrigerant that has passed through the first main heat exchanging unit to be in a superheating state.

Refrigerant is caused to be in a superheating state without impairing the performance of a cascade heat exchanger. A refrigerant cycle system includes a first refrigerant circuit, a second refrigerant circuit, and a first cascade heat exchanger. The first cascade heat exchanger exchanges heat between a first refrigerant that flows in the first refrigerant circuit and a second refrigerant that flows in the second refrigerant circuit. The refrigerant cycle system includes a switching mechanism. The switching mechanism switches a flow path of a refrigerant of at least either one of the first refrigerant circuit and the second refrigerant circuit. The first cascade heat exchanger includes a first main heat exchanging unit acid a first sub heat exchanging unit. The first sub heat exchanging unit is configured to cause the first refrigerant that has passed through the first main heat exchanging unit to be in a superheating state.

Disclosed is a refrigerant processing unit (1) for evaporating a refrigerant. The refrigerant processing unit (1) comprises a recirculation container (2) and a refrigerant inlet (3) connected to the recirculation container (2) for leading liquid refrigerant into the recirculation container (2). The refrigerant processing unit (1) also comprises a flooded evaporator heat exchanger (4) arranged to heat the liquid refrigerant to generate a phase change of the refrigerant from a liquid phase to a gaseous phase and a standpipe (5) extending between a liquid refrigerant outlet (6) of the recirculation container (2) and an evaporator inlet (28) of the flooded evaporator heat exchanger (4). Further, the refrigerant processing unit (1) comprises a return pipe (7) arranged to guide gaseous refrigerant from the flooded evaporator heat exchanger (4) back into the recirculation container (2) and a superheater heat exchanger (8) located below the recirculation container (2), wherein the superheater heat exchanger (8) is arranged to heat the gaseous refrigerant to generate a superheated gaseous refrigerant. Furthermore, the refrigerant processing unit (1) comprises a guide pipe (9) arranged to guide gaseous refrigerant from the recirculation container (2) into the superheater heat exchanger (8), and an outlet pipe (10) arranged to guide the superheated gaseous refrigerant out of the superheater heat exchanger (8) and thereby out of the refrigerant processing unit (1), wherein the flooded evaporator heat exchanger (4) and the superheater heat exchanger (8) are formed as a single heat exchanger unit (11) located below the recirculation container (2).

A method for evaporating a refrigerant and use of a refrigerant processing unit (1) is also disclosed.

Disclosed is a refrigerant processing unit (1) for evaporating a refrigerant. The refrigerant processing unit (1) comprises a recirculation container (2) and a refrigerant inlet (3) connected to the recirculation container (2) for leading liquid refrigerant into the recirculation container (2). The refrigerant processing unit (1) also comprises a flooded evaporator heat exchanger (4) arranged to heat the liquid refrigerant to generate a phase change of the refrigerant from a liquid phase to a gaseous phase and a standpipe (5) extending between a liquid refrigerant outlet (6) of the recirculation container (2) and an evaporator inlet (28) of the flooded evaporator heat exchanger (4). Further, the refrigerant processing unit (1) comprises a return pipe (7) arranged to guide gaseous refrigerant from the flooded evaporator heat exchanger (4) back into the recirculation container (2) and a superheater heat exchanger (8) located below the recirculation container (2), wherein the superheater heat exchanger (8) is arranged to heat the gaseous refrigerant to generate a superheated gaseous refrigerant. Furthermore, the refrigerant processing unit (1) comprises a guide pipe (9) arranged to guide gaseous refrigerant from the recirculation container (2) into the superheater heat exchanger (8), and an outlet pipe (10) arranged to guide the superheated gaseous refrigerant out of the superheater heat exchanger (8) and thereby out of the refrigerant processing unit (1), wherein the flooded evaporator heat exchanger (4) and the superheater heat exchanger (8) are formed as a single heat exchanger unit (11) located below the recirculation container (2).

A method for evaporating a refrigerant and use of a refrigerant processing unit (1) is also disclosed.