A thermal management system includes a refrigerant system, which includes a compressor, a flow control device, a valve member, a first heat exchanger, a second heat exchanger, and a third heat exchanger. The flow control device includes a first throttle unit, a second throttle unit, and a valve assembly; the flow control device includes a first port, a second port, and a third port; a first connection port of the first heat exchanger is in communication with the second port, and a first connection port of the second heat exchanger is in communication with the third port, while a first connection port of the third heat exchanger is in communication with the first port. The thermal management system includes a first operating state and a second operating state.

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.

An air conditioner includes an outdoor unit including a compressor, first and second indoor heat exchangers to receive a refrigerant from the outdoor unit, the second indoor heat exchanger receiving the refrigerant independently of the first indoor heat exchanger, and a fan disposed between the first and second indoor heat exchangers. First and second refrigerant pipes form flow paths between the outdoor unit and the first and second indoor heat exchangers. First and second expansion valves are disposed on the first and second refrigerant pipes. Third and fourth refrigerant pipes form flow paths between the compressor and the first and second indoor heat exchangers. A first opening and closing valve selectively opens and closes a fifth refrigerant pipe to selectively allow refrigerant to flow between the second and third refrigerant pipes. Second and third opening and closing valves selectively open and close the second and third refrigerant pipes.

A cooling system is designed to operate in two different modes. Generally, in the first mode, when parallel compression is needed, certain valves are controlled to direct gaseous refrigerant from a tank to a compressor in the system and to direct refrigerant from low side heat exchangers towards other compressors. In this manner, a compressor in the system is transitioned to be generally a parallel compressor. In the second mode, when parallel compression is not needed, the valves are controlled to return the refrigerant flow back to normal.

An air conditioning apparatus includes an outdoor device that is configured to circulate refrigerant and that includes a compressor and an outdoor heat exchanger, a plurality of indoor devices configured to circulate water, and a heat exchange device connecting the outdoor device with the indoor device. The heat exchange device includes a heat exchanger configured to exchange heat between the refrigerant and the water, and a switch device configured to control flow of refrigerant between the indoor devices and the heat exchanger.

An air conditioner may include a continuous refrigeration apparatus including a first gas control unit connected to a first indoor heat exchanger, a second gas control unit connected to a second indoor heat exchanger, a first pipe connecting a liquid pipe of an outdoor unit and a liquid of an indoor unit, and a second pipe branched from the first pipe and connected to the first and second gas control units. The first gas control unit may include a first-first flow path connecting the first gas control unit to the second pipe; a first-second flow path connected to the first-first flow path, and through which refrigerant discharged from the first indoor heat exchanger flows during a refrigeration operation; and a first-third flow path connected in parallel with the first-second flow path, and guiding refrigerant from the compressor to the first indoor heat exchanger during a defrosting operation.

A defrosting control method for a multi-split system is provided. A multi-split system comprises an outdoor unit and multiple indoor units. An expansion valve is provided on a connecting pipeline between each of the indoor units and the outdoor unit. When the expansion valve of each activated indoor unit is closed and the degree of opening of the expansion valve of each off-state indoor unit is less than or equal to a maximum set degree of opening, the system satisfies a defrosting requirement, and as a result the method controls the expansion valve of each activated indoor unit to remain closed, thereby resolving the issue of a dramatic temperature drop in a room having an activated indoor unit during defrosting and improving user satisfaction. The degree of opening of the expansion valve of a off-state indoor unit is Off_PLS, and is controlled such that Off_PLS=ALL_HP*Avg_PLS/Off_HP. The invention satisfies a defrosting requirement and reduces the degree of opening of the expansion valves as much as possible, thereby preventing damage to a compressor without affecting defrosting.

A modulating refrigeration system includes an evaporation unit and a condensing unit. The evaporation unit generates a first output airflow comprising a lower temperature, a lower relative humidity, or both than a first supply airflow and directs the first output airflow into a building. The condensing unit generates a second output airflow at a higher temperature than a second supply airflow and discharges the second output airflow to an unconditioned space. The evaporation unit comprises a first valve operable to direct a portion of refrigerant to a secondary evaporator and primary evaporator or to direct the entire flow of refrigerant to the primary evaporator and bypassing the secondary evaporator.

Provided is a multi-type air conditioner, including: an outdoor unit comprising a liquid pipe through which liquid refrigerant flows and a gas pipe through which gas refrigerant flows; a plurality of indoor units comprising a first indoor unit and a second indoor unit each connected to the liquid and gas pipelines to circulate a refrigerant; a gas pipe connecting tube connecting the gas pipe and a plurality of indoor units so that a gas refrigerant flows therethrough; a first gas branch pipe connecting the first indoor unit and the gas pipe connecting tube so that a gas refrigerant flows therethrough; a second gas branch pipe connecting the second indoor unit and the gas pipe connecting tube so that a gas refrigerant flows therethrough; an indoor heat exchanger connecting pipe connecting the first indoor unit and the second indoor unit so that a liquid refrigerant flows therethrough; and a liquid pipe connecting tube connecting the first indoor unit and the liquid pipe so that a liquid refrigerant flows therethrough.

The first indoor unit may include: a first heat exchanger configured to perform heat exchange between indoor air and a refrigerant, a second heat exchanger configured to perform heat exchange between indoor air and a refrigerant and arranged in a stacked fashion with the first heat exchanger; a first indoor fan configured to blow air to the first heat exchanger and the second heat exchanger; a first liquid branch pipe connecting the indoor heat exchanger connecting pipe and the first indoor heat exchanger; a first heat exchanger connecting pipe connecting the first liquid branch pipe and the first heat exchanger of the first indoor heat exchanger; a second heat exchanger connecting pipe connecting the first liquid branch pipe and a second heat exchanger of the first indoor heat exchanger; and a first indoor expansion valve disposed at the second heat exchanger connecting pipe, wherein an opening amount of the first indoor expansion valve is adjusted in response to an input signal from the controller to selectively expand a flowing refrigerant.

The liquid pipe connecting tube may connect the first heat exchanger and a liquid pipe, and the first gas branch pipe may connect the second heat exchanger and the gas pipe.

Since the multi-type air conditioner according to the present disclosure can operate the first heat exchanger as a condenser and the second heat exchanger as an evaporator among the indoor heat exchangers, it is possible to continuously drive the dehumidification mode while maintaining the room temperature within a certain range There are advantages.

An air conditioning apparatus includes an outdoor device that is configured to circulate refrigerant and that includes a compressor and an outdoor heat exchanger, a plurality of indoor devices configured to circulate water, and a heat exchange device that connects the outdoor device with the indoor device. The heat exchange device includes a heat exchanger configured to exchange heat between the refrigerant and the water, and a switch device configured to control flow of refrigerant between the indoor device and the heat exchanger.