A refrigeration cycle apparatus including a heat source side heat exchanger including a first heat exchanger and a second heat exchanger connected in parallel; an air-sending device that supplies air, which is an object to be heat exchanged in the first heat exchanger and the second heat exchanger, in a variable manner; solenoid valves that each opens and closes a refrigerant passage of the first heat exchanger and the second heat exchanger; a third refrigerant circuit that is parallelly connected to the first heat exchanger and the second heat exchanger; and a flow control valve that controls the flow rate of the refrigerant flowing in the third refrigerant circuit. The refrigeration cycle apparatus can improve continuity of control of a heat exchange capacity of a heat source side heat exchanger.

In a refrigeration cycle system, switching is allowed between a parallel operation mode and a series operation mode. In the parallel operation mode, a refrigerant, upon leaving a load side heat exchanger, parallelly flows through a high-pressure side passage of each of a first internal heat exchanger and a second internal heat exchanger and then flows into an expansion valve. In the series operation mode, the refrigerant, upon leaving the load side heat exchanger, flows through the high-pressure side passage of the first internal heat exchanger, further flows through the high-pressure side passage of the second internal heat exchanger, and then flows through a high-pressure side bypass pipe into the expansion valve.

A method for controlling a vapour compression system (1), the vapour compression system (1) comprising a compressor unit (2) comprising one or more compressors (10, 11, 13), is disclosed. At least one of the compressors (11, 13) of the compressor unit (2) is connectable to a gaseous outlet (9) of a receiver (5), and at least one of the compressors (10, 13) of the compressor unit (2) is connectable to an outlet of an evaporator (7). A parameter of the vapour compression system (1) is measured, an enthalpy of refrigerant leaving the heat rejecting heat exchanger (3) being derivable from the measured parameter. A setpoint value for a pressure inside the receiver (5) is calculated, based on the measured parameter, and the compressor unit (2) is operated in accordance with the calculated setpoint value, and in order to obtain a pressure inside the receiver (5) which is equal to the calculated setpoint value. The vapour compression system (1) is operated in an energy efficient manner over a wide range of ambient temperatures.

A heat exchanger includes a first manifold, a second manifold, a plurality of flat tubes, and a plurality of fins. Two ends of the first manifold are respectively sealed with a cap. The heat exchanger further includes a first connecting pipe, a second connecting pipe, and a third connecting pipe. The first connecting pipe communicates with the first manifold via a second opening, the second connecting pipe communicates with an allocation tube, and the third connecting pipe communicates with the second manifold. A diameter of the first connecting pipe is greater than the diameter of the allocation tube. The two connecting pipes of the heat exchanger correspond to refrigerant in different states. The diameters of the two connecting pipes are different such that the refrigerant in different states may be uniformly allocated, which contributes to the efficiency of the heat exchanger.

An air conditioning and heat pump tower includes a main casing, a plurality of connecting pipes, a compressor, a front heat exchanger, a rear heat exchanger, a fan unit, and an energy efficient arrangement. The energy efficient arrangement includes a first pre-heating heat exchanger supported in a front compartment of the main casing, and positioned between an outdoor air intake opening and an outdoor heat exchanging portion of the front heat exchanger. The air conditioning and heat pump tower may be operated between an air conditioning mode for absorbing heat from the indoor space, and a heat pump mode for producing heat to the indoor space. A predetermined amount of ambient air may be drawn through the outdoor air intake opening and may be pre-heated by the energy efficient arrangement before delivering to the indoor space.

A split-type air conditioning and heat pump system an indoor unit, an outdoor unit and an energy efficient arrangement. The indoor unit includes an indoor housing having an indoor air inlet, and an indoor heat exchanger. The outdoor unit includes an outdoor housing, a compressor, an outdoor heat exchanger and a fan unit. The energy efficient arrangement includes an energy saving heat exchanger supported in the indoor housing and connected to the indoor heat exchanger and the outdoor heat exchanger. The energy saving heat exchanger is positioned between the indoor air inlet and the indoor heat exchanger so that air from an indoor space is arranged to pass through the energy saving heat exchanger before reaching the indoor heat exchanger.

An air conditioning and heat pump system includes a main heat exchange system, a heat distribution system and an energy efficient arrangement. The energy efficient arrangement includes a first energy saver heat exchanger connected to a first main heat exchanger and the second main heat exchanger of the main heat exchange system, a second pumping device connected to the first energy saver heat exchanger, and a pre-heating heat exchanger supported in the supporting frame at a positioned between a ventilating heat exchanging unit and an air intake opening of a ventilating device. The pre-heating heat exchanger is connected to the second pumping device and the first energy saver heat exchanger.

An air conditioning system includes a refrigerant circuit including a compressor, an indoor heat exchanger, a first expansion valve, a gas-liquid separator, a second expansion valve, and an outdoor heat exchanger which are sequentially connected together to perform a two-stage expansion refrigeration cycle. The refrigerant circuit further includes: a gas injection pipe through which intermediate-pressure gas refrigerant in the gas-liquid separator flows into an intermediate port of the compressor, and a liquid-gas heat exchanger configured to exchange heat between low-pressure gas refrigerant obtained by evaporating refrigerant in the outdoor heat exchanger and travelling toward the compressor and intermediate-pressure liquid refrigerant travelling from the gas-liquid separator toward the second expansion valve.

The present application discloses a volute structure, a centrifugal compressor and a refrigeration device. The volute structure comprises: a cabinet (8), a volute casing (1) and a backflow device (5); the volute casing (1) comprises an inner volute and an outer volute separately provided, a fluid flow passage being formed between the inner volute and outer volute, and the inner volute and backflow device (5) being disposed together. The present application increases the length of the first-stage diffuser, improving the diffusion effect of air entering the first-stage diffuser and thus enhancing the unit performance of the centrifugal compressor.

A non-condensable gas purge system is configured to be used in a chiller system that uses a low pressure refrigerant in a loop refrigeration circuit. The non-condensable gas purge system includes a purge tank and a purge heat exchanger coil arranged inside the purge tank. The purge tank has a tank inlet for receiving the low pressure refrigerant from a condenser of the refrigeration circuit, a tank outlet for returning the low pressure refrigerant to an evaporator of the refrigeration circuit, and a purge outlet for purging non-condensable gas from the purge tank to the ambient atmosphere. The purge heat exchanger coil is fluidly connected to the loop refrigeration circuit such that the low pressure refrigerant contained in the loop of the chiller system can pass through the purge heat exchanger coil. Refrigerant in the purge tank is condensed by the heat exchanger coil while non-condensable gases remain gaseous.