A refrigeration and/or heat transfer device includes a heating section and cooling section, a release member, and a one-way check valve affixed together in a continuous loop so working fluid may flow in one direction therein. The heating section absorbs heat and transfers such heat to the working fluid, thereby heating, expanding and increasing pressure upon the working fluid therein. The pressurized working fluid is released in a regulated manner from the heating section to the cooling section, thereby carrying the heat away. The released working fluid cools and transfers its heat to the surroundings within the cooling section. As released working fluid enters the cooling section, such fluid displaces already cooled working fluid, pushing such fluid through the one-way check valve back into the heating section to absorb heat. The working fluid may undergo a phase change or remain in a single phase throughout to enhance heat transfer.

An enhanced vapor injection air conditioning system is provided and includes: a vapor injection compressor, a direction switching assembly, a first outdoor heat exchanger, a second outdoor heat exchanger including first and second heat-exchange flow passages, and an auxiliary electronic expansion valve assembly. A main electronic expansion valve assembly is connected between a first end of the first heat-exchange flow passage and a second end of the first outdoor heat exchanger. The auxiliary electronic expansion valve assembly has a first end connected with an inlet of the second heat-exchange flow passage, and a second end connected to a second end of the first heat-exchange flow passage or between the main electronic expansion valve assembly and the first heat-exchange flow passage. A ratio DB of a sum of a caliber of the main electronic expansion valve assembly to that of the auxiliary electronic expansion valve assembly has a range of 1DB7.

An enhanced vapor injection air conditioning system is provided and includes: a vapor injection compressor, a direction switching assembly, a first outdoor heat exchanger, a second outdoor heat exchanger including first and second heat-exchange flow passages, and an auxiliary electronic expansion valve assembly. A main electronic expansion valve assembly is connected between a first end of the first heat-exchange flow passage and a second end of the first outdoor heat exchanger. The auxiliary electronic expansion valve assembly has a first end connected with an inlet of the second heat-exchange flow passage, and a second end connected to a second end of the first heat-exchange flow passage or between the main electronic expansion valve assembly and the first heat-exchange flow passage. A ratio DB of a sum of a caliber of the main electronic expansion valve assembly to that of the auxiliary electronic expansion valve assembly has a range of 1DB7.

An ejector includes a body including an inflow space into which a refrigerant flows, a passage formation member disposed inside the body and having a conical shape, and a nozzle passage having an annular cross section functioning as a nozzle and a diffuser passage having an annular cross section functioning as a pressurizing portion between an inner wall surface of the body and a conical lateral surface of the passage formation member. A drive mechanism that displaces the passage formation member along a center axis is coupled to an upstream actuating bar which extends from the passage formation member toward the inflow space and is slidably supported by the body. A largest outer diameter portion of an annular member forming a wall surface of the nozzle passage provides a throat portion functioning as an edge for enlarging a passage cross-sectional area to cause a separation vortex in the refrigerant.

An ejector includes a body including an inflow space into which a refrigerant flows, a passage formation member disposed inside the body and having a conical shape, and a nozzle passage having an annular cross section functioning as a nozzle and a diffuser passage having an annular cross section functioning as a pressurizing portion between an inner wall surface of the body and a conical lateral surface of the passage formation member. A drive mechanism that displaces the passage formation member along a center axis is coupled to an upstream actuating bar which extends from the passage formation member toward the inflow space and is slidably supported by the body. A largest outer diameter portion of an annular member forming a wall surface of the nozzle passage provides a throat portion functioning as an edge for enlarging a passage cross-sectional area to cause a separation vortex in the refrigerant.

An ejector includes a nozzle, a swirl flow generation portion, a body including a refrigerant suction port and a diffuser portion, a passage forming member, and an actuation device moving the passage forming member. A nozzle passage is defined between the nozzle and the passage forming member. A smallest passage cross-sectional area portion is provided in the nozzle passage. A swirl space that has a shape of a revolution and is coaxial with the nozzle, and a refrigerant inflow passage through which the refrigerant flows into the swirl space are defined in the swirl flow generation portion. The ejector further includes an area adjustment device that changes the passage cross-sectional area of the refrigerant inflow passage. According to this, an efficiency of energy conversion in the nozzle passage can be improved.

An ejector includes a nozzle, a swirl flow generation portion, a body including a refrigerant suction port and a diffuser portion, a passage forming member, and an actuation device moving the passage forming member. A nozzle passage is defined between the nozzle and the passage forming member. A smallest passage cross-sectional area portion is provided in the nozzle passage. A swirl space that has a shape of a revolution and is coaxial with the nozzle, and a refrigerant inflow passage through which the refrigerant flows into the swirl space are defined in the swirl flow generation portion. The ejector further includes an area adjustment device that changes the passage cross-sectional area of the refrigerant inflow passage. According to this, an efficiency of energy conversion in the nozzle passage can be improved.

A thermally driven heat pump includes a low temperature evaporator for evaporating cooling fluid to remove heat A first heat exchanger located at an outlet of a converging/diverging chamber of a first ejector receives a flow of primary fluid vapor and cooling fluid vapor ejected from the first ejector for condensing a portion of the cooling fluid vapor An absorber located in the first heat exchanger absorbs cooling fluid vapor into an absorbing fluid to reduce the pressure in the first heat exchanger A second heat exchanger located at an outlet of a converging/diverging chamber of a second ejector receives primary fluid vapor and cooling fluid vapor ejected from the second ejector for condensing the cooling fluid vapor and the primary fluid vapor A separator in communication with the second ejector, the low temperature evaporator and the primary fluid evaporator separates the primary fluid from the cooling fluid.

A thermally driven heat pump includes a low temperature evaporator for evaporating cooling fluid to remove heat A first heat exchanger located at an outlet of a converging/diverging chamber of a first ejector receives a flow of primary fluid vapor and cooling fluid vapor ejected from the first ejector for condensing a portion of the cooling fluid vapor An absorber located in the first heat exchanger absorbs cooling fluid vapor into an absorbing fluid to reduce the pressure in the first heat exchanger A second heat exchanger located at an outlet of a converging/diverging chamber of a second ejector receives primary fluid vapor and cooling fluid vapor ejected from the second ejector for condensing the cooling fluid vapor and the primary fluid vapor A separator in communication with the second ejector, the low temperature evaporator and the primary fluid evaporator separates the primary fluid from the cooling fluid.

A method for controlling a vapour compression system (1) comprising an ejector (6) is disclosed. In the case that a pressure difference between a pressure prevailing in the receiver (7) and a pressure of refrigerant leaving the evaporator (9) decreases below a first lower threshold value, the pressure of refrigerant leaving the heat rejecting heat exchanger (5) is kept at a level which is slightly higher than the pressure level providing optimal COP. Thereby the ejector (6) can operate at lower ambient temperatures, and the energy efficiency of the vapour compression system (1) is improved.