In an air-conditioning apparatus, in the case where a compressor is in operation, a fan is in operation, a wind guide plate is in a first state and a second heat exchanger operates as a condenser, when a detected temperature of target space for air-conditioning is higher than a set temperature for the target space and a detected temperature of a second heat exchanger is lower than or equal to a first reference temperature, a controller performs a first control to keep the compressor and the fan in operation and switch the state of the wind guide plate from the first state to a second state.

An exemplary heat pump includes: an accumulator that separates liquid refrigerant from gas refrigerant returning to a compressor; a refrigerant suction channel connecting the compressor to the accumulator; a refrigerant return channel that returns liquid refrigerant in the accumulator to the refrigerant suction channel; a first valve disposed on the refrigerant return channel; a temperature sensor that detects a temperature of refrigerant in the refrigerant suction channel; a second valve that reduces a pressure of a part of liquid refrigerant flowing between the first and second heat exchangers; a refrigerant evaporator that gasifies, by using waste heat of an engine, the liquid refrigerant whose pressure has been reduced; a gas refrigerant supply channel through which the gasified refrigerant is supplied to the accumulator; and a control device that, while the first valve is open, controls an opening of the second valve based on the temperature detected by the temperature sensor.

An air-conditioning apparatus according to the present invention includes: a heat-source-side unit including a heat-source-side heat exchanger and a compressor; a plurality of load-side units including respective load-side heat exchangers and respective load-side expansion devices; and a relay unit connected between the heat-source-side unit and the plurality of load-side units by a first gas pipe and a first liquid pipe. The relay unit includes a gas/liquid separator which separates refrigerant supplied from the heat-source-side unit into gas refrigerant and liquid refrigerant, a gas-refrigerant supply pipe and a liquid-refrigerant supply pipe which are connected to the gas/liquid separator and each of the plurality of load-side units, a drain pan which is provided in a housing of the relay unit and which receives dew-condensation water, and a heat transfer body which is provided in the drain pan and which is in contact with the liquid-refrigerant supply pipe.

A refrigeration cycle apparatus includes at least a compressor, a condenser, an internal heat exchanger configured to exchange heat between parts of refrigerant each having a different pressure, a refrigerant reservoir configured to store the refrigerant, a first pressure reducing device, an evaporator. The compressor, the condenser, the internal heat exchanger, the refrigerant reservoir, the first pressure reducing device, and the evaporator are sequentially connected to each other. The refrigeration cycle apparatus also includes a first pipe connecting the condenser and the refrigerant reservoir, and a second pressure reducing device provided to the first pipe between the internal heat exchanger and the refrigerant reservoir.

A refrigeration cycle apparatus using refrigerant including HFO-1123, the refrigeration cycle apparatus including a compressor, a condenser, an expansion valve, and an evaporator connected in a loop, and a cooling unit configured to cool the refrigerant at an inlet of the expansion valve.

A cooling system drains oil from low side heat exchangers to vessels and then uses compressed refrigerant to push the oil in the vessels back towards a compressor. Generally, the cooling system operates in three different modes of operation: a normal mode, an oil drain mode, and an oil return mode. During the normal mode, a primary refrigerant is cycled to cool one or more secondary refrigerants. As the primary refrigerant is cycled, oil from a compressor may mix with the primary refrigerant and become stuck in a low side heat exchanger. During the oil drain mode, the oil in the low side heat exchanger is allowed to drain into a vessel. During the oil return mode, compressed refrigerant is directed to the vessel to push the oil in the vessel back towards a compressor.

An air conditioning system, a refrigerant state detection method and a computer-readable storage medium. By adjusting first operating parameters of the air conditioning system, where the first operating parameters include a frequency of a compressor, a wind speed setting, and an opening degree of an electronic expansion valve; collecting second operating parameters of the air conditioning system at a preset time after the first operating parameters have been adjusted, where the second operating parameters include an outdoor environment temperature and operating parameters of the compressor; and determining a refrigerant state of the air conditioning system according to the second operating parameters.

An air conditioner may include a case through which outdoor air flows into an indoor space is formed; a first heat exchanger that exchanges heat between the air and refrigerant; a second heat exchanger disposed downstream of the first heat exchanger, through which the refrigerant selectively flows, and that exchanges heat between the air and the refrigerant; a liquid pipe connected to each of the first and second heat exchangers; a high-pressure gas pipe connected to each of the first and second heat exchangers; a low-pressure gas pipe through which the gaseous refrigerant discharged from the first and second heat exchangers flows; a high-pressure gas pipe valve; a low-pressure gas pipe valve; an expansion valve installed in the liquid pipe; and a controller configured to control an opening degree of the low-pressure gas pipe valve, based on a temperature of the refrigerant flowing through the first heat exchanger.

A heat pump system includes a refrigerant circuit in which a compressor, a refrigerant flow path included in a heat medium heat exchanger, an expansion valve, and a heat source side heat exchanger are connected, the heat medium heat exchanger including the refrigerant flow path and a heat medium flow path; a heat medium feed path connected to the heat medium flow path included in the heat medium heat exchanger; an indoor unit connected to the heat medium feed path and configured to condition air inside a room; a room temperature sensor configured to detect an indoor temperature in the room; a heat medium temperature sensor configured to detect a temperature of a heat medium that flows into the indoor unit; and a controller configured to control the refrigerant circuit or the indoor unit by using a set temperature in the room.

A test chamber and a method for conditioning air in which the test chamber comprises a temperature-insulated test space, which is closable to an environment and serves to receive test material, and a temperature control device for controlling the test space in temperature, a temperature ranging from 40 C. to +180 C. being generable within the test space by the temperature control device. The temperature control device comprises a cooling apparatus having a first and second cooling cycle, the first cooling cycle having a first refrigerant, a first heat exchanger, a first compressor, a first condenser and a first expansion element, the first refrigerant being a hydrocarbon or a refrigerant mixture made of hydrocarbons. The second cooling cycle has a heat transfer medium, a second heat exchanger in the test space and a pump, the second cooling cycle being coupled to the first cooling cycle by the first heat exchanger.