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 multi-split system and a medium-pressure controlling method thereof are provided. The multi-split system includes an outdoor unit, a distribution device, and a plurality of indoor units. The distribution device includes a gas-liquid separator, a first heat exchange assembly, a first electronic expansion valve, a second heat exchange assembly and a second electronic expansion valve. The distribution device is configured to perform a routine correction on a medium-pressure control target value of the first electronic expansion valve according to the subcooling degree of the heating indoor unit, the outlet air temperature of the heating indoor unit and the opening of the throttling element in the heating indoor unit, and to correct a current medium-pressure control target value of the first electronic expansion valve according to a preset step when the opening of the throttling element reaches a maximum opening or a minimum opening and lasts for a first preset time.

A channel on an upstream side of a third expansion device and a channel on an upstream side of a second expansion device are connected during a heating operation, and medium pressure refrigerant generated by the third expansion device during the heating operation is introduced on a suction side of a compressor via the second expansion device and a suction injection pipe.

An air-conditioning apparatus includes a refrigerant circuit, a heat medium circuit, and a controller. In the refrigerant circuit, a compressor, a heat-source-side heat exchanger, an expansion unit, and a load-side heat exchanger are connected by refrigerant pipes, and refrigerant flows. The heat-source-side heat exchanger causes heat exchange to be performed between the refrigerant and a heat-source heat medium. The load-side heat exchanger causes heat exchange to be performed between the refrigerant and a load heat medium, and refrigerant flows. In the heat medium circuit, a flow control valve that regulates the flow rate of the heat-source heat medium and the heat-source-side heat exchanger are connected by a heat medium pipe, and the heat-source heat medium flows. The controller includes a storage unit that stores data indicating a defined maximum flow rate and a defined minimum flow rate of the heat-source heat medium that flows in the heat medium circuit.

An air-conditioning apparatus includes an outdoor unit and a relay unit. The outdoor unit includes a compressor compressing and discharging refrigerant and a heat-source-side heat exchanger performing heat exchange between the refrigerant and outside air. The relay unit and the outdoor unit form a refrigerant circuit. The outdoor unit includes first and flow switching devices each switching an associated flow passage for the refrigerant between a plurality of flow passages, according to an operation mode. An outflow pipe and an inflow pipe through which refrigerant flows from the outdoor unit to the relay unit and from the relay unit into the outdoor unit, respectively, are between the outdoor unit and the relay unit. The first flow switching device is connected to the compressor, the second flow switching device, and the outflow pipe. The second flow switching device is connected to the first flow switching device and the inflow pipe.

An air-conditioning apparatus that includes a compressor, a flow switching device, an outdoor heat exchange unit, an expansion section and an indoor heat exchanger, which are connected by pipes, in which the outdoor heat exchange unit includes a first outdoor heat exchanger, a first flow rate control device, a second outdoor heat exchanger, a second flow rate control device, a bypass pipe, the second outdoor heat exchanger, the second flow rate control device, a third flow rate control device, and a flow control device.

A refrigeration cycle apparatus includes a refrigeration cycle circuit connecting a compressor, a refrigerant flow switching device, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger, a first junction portion provided between the outdoor heat exchanger and the expansion valve and configured to divide refrigerant, a second junction portion provided between the indoor heat exchanger and the refrigerant flow switching device and configured to divide the refrigerant, a bypass pipe connecting the first junction portion and the second junction portion and configured to cause the refrigerant to flow through the bypass pipe, a first valve provided between the second junction portion and the refrigerant flow switching device, a second valve provided to the bypass pipe, a first temperature sensor configured to measure a temperature in a room to which air passing through the indoor heat exchanger is provided, and a second temperature sensor configured to measure a temperature of refrigerant at a liquid portion of the indoor heat exchanger. In an operation status in which the compressor operates, the expansion valve is fully closed, the first valve is opened, and the second valve is closed, when a temperature measured by the first temperature sensor and a temperature measured by the second temperature sensor are different from each other, the refrigeration cycle apparatus is configured to detect an abnormality at at least one of the expansion valve and the second valve.

An air conditioning apparatus is provided that may include an outdoor unit including a compressor and an outdoor heat exchanger and through which a refrigerant is circulated, an indoor unit through which a fluid, such as water is circulated, and at least one heat exchange device including a heat exchanger in which the refrigerant and the fluid are heat-exchanged with each other. The at least one heat exchange device may include a high-pressure guide tube that extends from a high-pressure gas tube of the outdoor unit so as to be connected to a first side of the heat exchanger, a low-pressure guide tube that extends from a low-pressure gas tube of the outdoor unit so as to be combined with the high-pressure guide tube, a liquid guide tube that extends from a liquid tube of the outdoor unit so as to be connected to a second side of the heat exchanger, and a solenoid valve installed in the high-pressure guide tube or the low-pressure guide tube to perform an opening and closing operation so as to allow the refrigerant to flow in a first direction. The high-pressure gas tube and the low-pressure gas tube may be connected to each other by a single gas tube, and when the indoor unit performs a cooling operation or a heating operation, flow of refrigerant in the first direction may be blocked in a state in which power is applied to the solenoid valve.

An air-conditioning apparatus includes an outdoor unit including an outdoor heat exchanger; an indoor unit including an indoor heat exchanger; and a relay unit provided between the outdoor unit and the indoor unit and including one or more first refrigerant supply pipes and one or more second refrigerant supply pipes that are connected to the indoor heat exchanger of the indoor unit. The one or more first refrigerant supply pipes and the one or more second refrigerant supply pipes protrude from the same side surface of the relay unit. The one or more first refrigerant supply pipes are each provided above an associated one of the one or more second refrigerant supply pipes. Part of the one or more first refrigerant supply pipes that protrudes from the side surface is longer than part of the one or more second refrigerant supply pipes that protrudes from the side surface.

A temperature control system, including a closed refrigerant circuit having an evaporator unit for absorbing heat via the refrigerant, thereby evaporating it, a compressor unit with a mechanical compressor for increasing the pressure of the refrigerant and a thermal collector for using an external heat source to increase the temperature of refrigerant within the circuit, and a condenser unit for rejecting heat from the refrigerant, liquefying it.