Provided is an air conditioning apparatus. The air conditioning apparatus includes an outdoor unit through which a refrigerant circulates, a plurality of indoor units through which water circulates, the plurality of indoor units comprising a first indoor heat exchanger and a second indoor heat exchanger, and a heat-exchange device configured to connect the outdoor unit to the indoor unit, the heat exchange device including a first heat exchanger and a second heat exchanger, in which the refrigerant and water are heat exchanged with each other. The heat exchange device includes a first inflow tube extending from the first indoor heat exchanger toward the first heat exchanger to guide a flow of the water, a second inflow tube extending from the second indoor heat exchanger toward the second heat exchanger to guide the flow of the water, a first pump provided in the first inflow tube and a second pump provided in the second inflow tube. When a portion of the indoor unit performs a heating operation, and the other portion of the indoor unit performs a cooling operation, when a total capacity required for the indoor unit is equal to or less than a set capacity, the first pump or the second pump operates, and when the total capacity required for the indoor unit exceeds the set capacity, the first pump and the second pump operate.

An air conditioning apparatus includes an outdoor unit configured to circulate refrigerant, an indoor unit configured to circulate water, and a heat exchange device that connects the indoor unit to the outdoor unit and that is configured to perform heat exchange between the refrigerant and the water. The heat exchange device includes a first heat exchanger and a second heat exchanger, a first refrigerant pipe and a second refrigerant pipe that are connected to the first heat exchanger, a third refrigerant pipe and a fourth refrigerant pipe that are connected to the second heat exchanger, a first expansion valve disposed at the second refrigerant pipe, a second expansion valve disposed at the fourth refrigerant pipe, a bypass pipe that connects the second refrigerant pipe to the third refrigerant pipe, and a bypass valve disposed at the bypass pipe.

An air conditioner includes: a heat-source-side unit including a compressor and a heat-source-side heat exchanger; use-side units each including a use-side heat exchanger; an intermediate unit that causes the use-side heat exchanger of each of the use-side units to individually function as an evaporator or a radiator of a refrigerant; and three or more connection pipes that connect the heat-source-side unit to the intermediate unit. The intermediate unit includes: an ejector that pressurizes the refrigerant; and a gas-liquid separator into which the refrigerant flowing out from the ejector flows. The refrigerant that has released heat in any of the use-side units that perform a heating operation is not pressurized by the ejector.

A safety system for a heat pump system includes a plurality of valve units each having refrigerant pipe portions with control valves, a refrigerant leakage detector, and a casing accommodating the valves and the refrigerant leakage detector and formed with first and second openings. The safety system further includes a connection structure connecting the internal spaces of the casings via the first and second openings, and a discharge structure connected to the connection structure or one of the casings and configured to discharge air from the internal space of the casing in which a refrigerant leakage has occurred. The casing has first and second lateral faces facing different directions, and the first opening is formed in the first lateral face and the second opening is formed in the second lateral face.

An air conditioner includes a bypass pipe connecting a first bypass branch of a first connection pipe, through which high-pressure refrigerant flows, with a second bypass branch of a third connection pipe, through which low-pressure refrigerant flows, to allow bypassing of high-pressure refrigerant in the first connection pipe to the third connection pipe, and a bypass valve mounted in the bypass pipe. During a cooling operation of an indoor unit, the bypass valve is opened to allow bypassing of high-pressure refrigerant of the first connection pipe to the third connection pipe.

An air conditioning apparatus may include an outdoor unit through which a first fluid, such as refrigerant circulates, an indoor unit through which a second fluid, such as water circulates, a heat exchange device which is configured to connect the outdoor unit to the indoor unit and in which the first fluid and the second fluid are heat-exchanged with each other, first to third inner tubes configured to connect the outdoor unit to the heat exchange device, and a heat storage unit connected to the first to third inner tubes.

Provided is an air conditioning apparatus. The air conditioning apparatus includes an outdoor unit through which a refrigerant is circulated, an indoor unit through which water is circulated, and a heat exchange device including a heat exchanger in which the refrigerant and the water are heat-exchanged with each other. The heat exchanger includes a high-pressure guide tube, a low-pressure guide tube, a liquid guide tube, a bypass tube configured to connect a bypass branch point of the high-pressure gas tube of the outdoor unit to a bypass combination point of the liquid guide tube to bypass a high-pressure refrigerant existing in the high-pressure tube to the liquid guide tube, and a bypass valve installed in the bypass tube. The outdoor unit includes a first valve device configured to guide a refrigerant compressed in the compressor to the outdoor heat exchanger and a second valve device configured to guide the refrigerant compressed in the compressor to the high-pressure guide tube of the heat exchange device.

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 refrigeration cycle system includes a first cycle and a second cycle. The first cycle is connected with a first compressor, a cascade heat exchanger, a first expansion unit, and a first heat exchanger, and includes a first flow path that connects the first compressor to the cascade heat exchanger, a second flow path that connects the cascade heat exchanger to the first expansion unit, a third flow path that connects the first heat exchanger to the first compressor, and a bypass flow path that connects at least one of the first flow path and the second flow path to the third flow path. The second cycle includes the cascade heat exchanger. In a case of using the cascade heat exchanger as a radiator of the first cycle and a heat sink of the second cycle, the first compressor of the first cycle is started after a flow of a heat medium generates in the cascade heat exchanger in the second cycle.

A refrigeration cycle apparatus includes a primary-side refrigerant circuit in which a first refrigerant circulates and a secondary-side refrigerant circuit in which a second refrigerant circulates. The primary-side refrigerant circuit includes a primary-side compressor, a primary-side flow path of a cascade heat exchanger, a primary-side heat exchanger, and a primary-side switching mechanism. The secondary-side refrigerant circuit includes a secondary-side compressor, a secondary-side flow path of the cascade heat exchanger, a secondary-side switching mechanism, a suction flow path, a plurality of utilization-side heat exchangers, a first connection flow path, connecting the plurality of utilization-side heat exchangers and the secondary-side switching mechanism, including a secondary-side first connection pipe, a first heat source pipe, first branch pipes, junction pipes, first connection pipes, and first utilization pipes, a second connection flow path, connecting the plurality of utilization-side heat exchangers and the suction flow path, including a secondary side second connection pipe, a second heat source pipe, second branch pipes, the junction pipes, the first connection pipes, and the first utilization pipes, a third connection flow path, connecting the plurality of utilization-side heat exchangers and the secondary-side flow path of the cascade heat exchanger, including a secondary-side third connection pipe, a fourth heat source pipe, a fifth heat source pipe, third branch pipes, second connection pipes, and second utilization pipes.