An air conditioner that has a controller and is such that an outdoor unit, which is provided with a compressor, an outdoor heat exchanger, an accumulator, and a supercooling heat exchanger, and indoor units provided with indoor heat exchangers, are connected to each other by connecting piping to constitute a refrigerant circuit. The bottom of the accumulator is connected to an intake side of the compressor via return bypass piping that is provided with an electromagnetic valve. The cooling source for the supercooling heat exchanger is a supercooling bypass circuit provided with a supercooling expansion valve; and when the amount of refrigerant during heating operation is determined to be excessive, the controller performs a control so as to fully close the electromagnetic valve of the return bypass piping and to gradually increase the opening degree of the supercooling expansion valve of the supercooling bypass circuit from a fully closed state.

A system includes a flash tank and a thermal storage tank. The flash tank is configured to store refrigerant and discharge a flash gas. The thermal storage tank is fluidically coupled to the flash tank and configured, when a power outage is determined to be occurring, to receive at least a portion of the flash gas from the flash tank, and remove heat from the flash gas. When a power outage is determined not to be occurring, the thermal storage tank directs refrigerant to a compressor.

A system includes a high side heat exchanger, a flash tank, a first load, a second load, and a thermal storage tank. The high side heat exchanger is configured to remove heat from a refrigerant. The flash tank is configured to store the refrigerant from the high side heat exchanger and discharge a flash gas. The first load is configured to use the refrigerant from the flash tank to remove heat from a first space proximate to the first load. The second load is configured to use the refrigerant from the flash tank to remove heat from a second space proximate to the second load. The thermal storage tank is configured, when a power outage is determined to be occurring, to receive at least a portion of the flash gas from the flash tank, and remove heat from the flash gas.

An air conditioner, a heating control method of an air conditioner, and a computer readable storage medium are provided. According to the method, a refrigerant passing through an evaporator is divided by a shunting module into two flows; one flow of the refrigerant is throttled and depressurized by an enhanced vapor injection electronic expansion valve. Based on a difference between an indoor pipe temperature and an exhaust temperature of a compressor of the air conditioner, an opening degree parameter of the enhanced vapor injection electronic expansion valve is controlled to control a refrigerant output amount by the enhanced vapor injection electronic expansion valve. Thus, the refrigerant amount of the flow of refrigerant, subject to throttling and depressurizing, for exchanging heat with the other flow of refrigerant can be controlled to implement an enhanced vapor injection function.

A multi-type air conditioner is provided that includes an outdoor unit having a liquid pipe through which a liquid refrigerant flows, and a gas pipe through which a gas refrigerant flows; a plurality of indoor units including a first indoor unit and a second indoor unit each connected to the liquid pipe and the gas pipe to circulate a refrigerant; a gas pipe connecting tube connecting the gas pipe and the plurality of indoor units so that a gas refrigerant flows therethrough; and a liquid pipe connecting tube connecting the liquid pipe and the plurality of indoor units so that a liquid refrigerant flows therethrough.

A refrigeration cycle apparatus includes a refrigerant that is R466A, a compressor that compresses the refrigerant, and a refrigeration machine oil that includes a base oil containing polyolester and that lubricates the compressor, wherein a kinematic viscosity of the refrigeration machine oil at 40° C. is 1.05 times or higher than and 1.50 times or lower than a kinematic viscosity of an other refrigeration machine oil at 40° C. that includes a base oil containing polyolester, the other refrigeration machine oil appropriately lubricating the compressor in an other refrigeration cycle apparatus including R410A as a refrigerant when the R410A is compressed by the compressor.

A refrigeration cycle apparatus that can improve operation efficiency when a refrigerant that contains at least 1,2-difluoroethylene is used is provided. An air conditioning apparatus 1 includes a compressor (21), an outdoor heat exchanger (23), an outdoor expansion valve (24), an indoor heat exchanger (31), and a suction injection pipe (40), and uses a refrigerant that contains at least 1,2-difluoroethylene. The suction injection pipe (40) allows a part of a refrigerant that flows toward the indoor heat exchanger (31) from the outdoor heat exchanger (23) to merge with a low-pressure refrigerant that is sucked into the compressor (21).

A heat source unit and a refrigeration cycle apparatus that are able to reduce damage to a connection pipe when a refrigerant containing at least 1,2-difluoroethylene is used are provided. An outdoor unit (20) that is connected via a liquid-side connection pipe (6) and a gas-side connection pipe (5) to an indoor unit (30) including an indoor heat exchanger (31) and that is a component of an air conditioner (1) includes a compressor (21) and an outdoor heat exchanger (23). A refrigerant containing at least 1,2-difluoroethylene is used as a refrigerant. A design pressure of the outdoor unit (20) is lower than 1.5 times a design pressure of each of the liquid-side connection pipe (6) and the gas-side connection pipe (5).

A heat pump includes a compressor for compressing a refrigerant, a first heat exchanger, a main expansion mechanism and a second heat exchanger arranged in a refrigeration path, the compressor having a suction port, a compression port and an injection port; a gas injection valve connected on a first side to the refrigeration path between the first heat exchanger and the main expansion mechanism and on a second side to the injection port of the compressor; a liquid injection valve connected on a first side to the refrigeration path between the first heat exchanger and the main expansion mechanism and on a second side between the second heat exchanger and the suction port of the compressor; and a controller, the controller being configured to operate the gas injection valve to inject at least partly gaseous refrigerant into the compressor through the injection port of the compressor, and to operate the liquid injection valve to inject substantially liquid refrigerant into the compressor through the suction port of the compressor.

A method for controlling a vapour compression system (1) is disclosed. The vapour compression system (1) includes an ejector (4), and has a non-return valve (11) arranged in the refrigerant path between an outlet (12) of an evaporator (7) and an inlet (10) of a compressor unit (2), in such a manner that a refrigerant flow from the outlet (12) of the evaporator (7) towards the inlet (10) of the compressor unit (2) is allowed, while a fluid flow from the inlet (10) of the compressor unit (2) towards the outlet (12) of the evaporator (7) is prevented. A pressure, P.sub.0, of refrigerant leaving the evaporator (7) is measured and a value being representative for a pressure, P.sub.suc, of refrigerant entering the compressor unit (2) is obtained. The pressures, P.sub.0 and P.sub.suc, are compared to respective reference pressure values, P.sub.0,ref and P.sub.suc,ref. In the case that ε.sub.0>ε.sub.suc, where ε.sub.0=P.sub.0−P.sub.0,ref and ε.sub.suc=P.sub.suc−P.sub.suc,ref, the compressor unit (2) is controlled based on P.sub.0, and in the case that ε.sub.suc>ε.sub.0, the compressor unit (2) is controlled based on P.sub.suc.