A refrigeration cycle apparatus includes: a compressor, a first outdoor heat exchanger, and a second outdoor heat exchanger that; and a flow path switching mechanism configured to switch a flow direction of refrigerant compressed by the compressor in the refrigerant circuit. The first outdoor heat exchanger and the second outdoor heat exchanger are arranged to allow the refrigerant to flow in parallel in the refrigerant circuit. The refrigeration cycle apparatus further includes a flow rate adjustment mechanism configured to adjust an amount of refrigerant flowing through the second outdoor heat exchanger. When switching between a cooling operation and a heating operation, the flow path switching mechanism switches the flow direction of the refrigerant while the flow rate adjustment mechanism temporarily closes a refrigerant flow path to the second outdoor heat exchanger.

Provided is an air conditioning apparatus. The air conditioning apparatus includes an outdoor unit which includes a compressor and an outdoor heat exchanger and through which a refrigerant is circulated, an indoor unit through which water is circulated, a heat exchanger in which the refrigerant and the water are heat-exchanged with each other, a water tube configured to guide the water circulated through the indoor unit and the heat exchanger, a pump installed in the water tube, and a controller configured to analyze an output signal of the pump so as to calculate a ration of an air layer in the water tube, the controller being configured to control a target supercooling degree or target superheating degree of the heat exchanger according to the calculated ratio of the air layer.

A multi-type air conditioner is provided including an outdoor unit and a plurality of indoor units connected to the outdoor unit by a liquid pipe and a gas pipe. The plurality of indoor units includes a first indoor unit including first and second heat exchangers and first and second heat exchanger connecting pipes, and a second indoor unit. An indoor heat exchanger connecting pipe connects the first and second indoor units, and a liquid pipe connecting tube connects the first indoor unit and the liquid pipe. Opening amounts of a first indoor expansion valve, and first and second bypass expansion valves provided in the first indoor unit are opened selectively to operate the first heat exchanger as a condenser and the second heat exchanger as an evaporator to continuously drive a dehumidification mode while maintaining a room temperature within a predefined range.

An indoor unit for heating, cooling, and dehumidifying air is disclosed. In an embodiment, the indoor unit includes a first coil assembly and a second coil assembly. When operating in a cooling mode or a heating mode, the first coil and second coil are in parallel fluid communication. When in a dehumidifying mode, the first coil and second coil are in serial fluid communication, which enables the first coil to function as a condenser and the second coil to function as an evaporator. The disclosed indoor unit provides negligible or no change in sensible heat while providing dehumidification.

A system controls a multi-zone vapor compression system (MZ-VCS). The system includes a controller to control a vapor compression cycle of the MZ-VCS using a set of control inputs determined by optimizing a cost function including a set of control parameters. The optimizing is subject to constraints, and wherein the cost function is optimized over a prediction horizon. The system also includes a memory to store an optimization function parameterized by a configuration of the MZ-VCS defining active or inactive modes of each heat exchanger, the optimization function modifies, according to a current configuration, values of the control parameters of the cost function determined for a full configuration that includes all heat exchangers in the active mode. The system also includes a processor to determine the current configuration of the MZ-VCS and to update the cost function by submitting the current configuration to the optimization function.

A refrigeration apparatus includes a heat source-side unit and a utilization-side unit that are connected to each other, and performs a refrigeration cycle in which a high pressure of a refrigerant reaches or exceeds a critical pressure. The refrigeration apparatus also includes a control unit configured to perform a first action of returning the refrigerant to the heat source-side unit when a stop condition of the utilization-side unit is satisfied, and a second action of prohibiting the first action when a pressure at the heat source-side unit is equal to or more than the critical pressure of the refrigerant. This configuration suppresses damage to a refrigerant storage reservoir and the like in returning the refrigerant to the heat source-side unit.

A system and related methods for heating, cooling, and dehumidifying air is disclosed. In an embodiment, the system includes an indoor unit having a first coil assembly and a second coil assembly. When the system is operating in a cooling mode or a heating mode, the first coil and second coil are in parallel fluid communication. When the system is in a dehumidifying mode, the first coil and second coil are in serial fluid communication, which enables the first coil to function as a condenser and the second coil to function as an evaporator. In an embodiment, the system includes an outdoor unit, such as a heat pump or an air conditioning condensing unit. The outdoor unit includes a heat exchanger fan responsive to dehumidifying mode by reducing fan speed, or deactivating the fan entirely. The disclosed system provides negligible or no change in sensible heat while providing dehumidification.

An air conditioning system including a four-way valve including a first port, a second port, a third port and a fourth port, at least the first port and the third port are fluidly isolated; a compressor, an output end and an input end of which are in communication with the first port and the third port respectively; a first evaporator, a first end of which is in communication with the third port; a second evaporator and a condenser, first ends of which are in communication with one of the second port and the fourth port respectively; wherein a second end of the condenser, a second end of the first evaporator, and a second end of the second evaporator are in communication at a first node, and a first throttling valve, a second throttling valve and a third throttling valve are respectively disposed between the condenser and the first node.

An air conditioner including an outdoor unit, an air conditioning indoor unit, a showcase indoor unit, and a combination unit. The combination unit includes a first gas control unit connected to the air conditioning indoor unit gas pipe, a second gas control unit connected to the showcase indoor unit gas pipe, a first pipe which connects the outdoor unit liquid pipe and the indoor unit liquid pipe, and a second pipe which connects the first pipe and the second gas control unit. The first gas control unit and the second gas control unit are converged to be connected to the outdoor unit gas pipe, so that the air conditioning indoor unit and the showcase indoor unit can use a single outdoor unit, and heat emitted from the air conditioning indoor unit to a room during a heating operation is used as condensation heat of the showcase indoor unit.

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.