Mitsubishi Electric Corporation

Komei Nakajima

Kosuke Tanaka

Masakazu Sato

Yusuke Tashiro

Hiroaki Makino

Naoki Nakagawa

Yusuke Adachi

Yasuhide Hayamaru

Kazuhide Yamamoto

Akinori Sakabe

Atsushi Morita

Haruo Nakano

Hideki Tsukino

Yusuke Tsuboi

A refrigeration cycle apparatus includes a compressor, a four-way valve, a first outdoor heat exchanger, a first expansion valve, and an indoor heat exchanger. The four-way valve includes a casing, a first flow channel, a second flow channel, a flow channel switching piston, and a wall portion. The flow channel switching piston is configured to slide along an inner surface to switch between passing the refrigerant through the first flow channel and passing the refrigerant through the second flow channel. The wall portion is configured to slide along the inner surface together with the flow channel switching piston and is disposed with a space between the flow channel switching piston and wall portion to cover the flow channel switching piston.

Refrigeration cycle apparatus

An outdoor unit includes a casing including an air passage, an outdoor fan disposed in the air passage, a compressor disposed in the casing, an outdoor heat exchanger disposed in the casing and including fins and a heat transfer tube connected to the fins, a control board disposed in the casing and including a control unit that controls the compressor, and a heat sink disposed in the air passage in the casing and being in contact with the control board. The heat transfer tube of the outdoor heat exchanger includes a first region in which gas refrigerant or two-phase gas-liquid refrigerant flows when the outdoor heat exchanger is used as a condenser and a second region that is located downstream of the first region in a refrigerant flow direction and in which single-phase liquid refrigerant flows.

Outdoor unit

An air-conditioning apparatus includes a first flow switching unit configured to be switched between a first state in which refrigerant communication between a compressor and a second load-side heat exchanger is blocked and a second state in which the compressor is in refrigerant communication with a first load-side heat exchanger and the second load-side heat exchanger. The air-conditioning apparatus further includes a second flow switching unit configured to be switched between a third state in which refrigerant communication between the second load-side heat exchanger and a heat-source-side heat exchanger is blocked and a fourth state in which the first load-side heat exchanger is in refrigerant communication with the second load-side heat exchanger and the heat-source-side heat exchanger. The first heat exchanger is located upstream of the second load-side heat exchanger. The second flow switching unit is located downstream of the second load-side heat exchanger.

Air-conditioning apparatus provided with refrigerant circuit capable of performing heating operation

An air conditioner allows refrigerant to circulate therethrough. The air conditioner includes a compressor, a first heat exchanger, a first expansion valve, a second heat exchanger, and a controller. The controller changes an opening degree of the first expansion valve by a first operation amount according to a temperature difference between a target temperature and the temperature of the refrigerant discharged by the compressor. The refrigerant circulates through the compressor, the first heat exchanger, the first expansion valve, and the second heat exchanger. A first ratio when a specific condition is satisfied is larger than a second ratio when the specific condition is not satisfied. The specific condition indicates that the degree of subcooling of the refrigerant flowing between the first heat exchanger and the first expansion valve is smaller than zero. The first and second ratios are each a ratio of the first operation amount to the temperature difference.

Air conditioner and expansion valve control thereof

An air conditioner includes a compressor, a condenser, an expansion valve, an evaporator, and a temperature detection unit. The temperature detection unit is attached to the condenser and is configured to detect a temperature of the refrigerant in the condenser. The expansion valve is configured to be capable of adjusting a flow rate per unit time of the refrigerant flowing through the expansion valve by adjusting a degree of opening of the expansion valve. The degree of opening of the expansion valve is increased when the temperature of the refrigerant detected by the temperature detection unit rises, and the degree of opening of the expansion valve is decreased when the temperature of the refrigerant detected by the temperature detection unit falls.

Air conditioner

An apparatus includes a refrigerant circuit in which a compressor that compresses a refrigerant, an indoor-side heat exchanger serving as a radiator that exchanges heat between the refrigerant and a heating target, an expansion valve that decompresses the refrigerant by opening-degree adjustment, and an outdoor-side heat exchanger serving as an evaporator that exchanges heat between a heat-exchange target and the refrigerant are connected by pipes. The apparatus includes: an outdoor air temperature sensor that detects a temperature of outdoor air serving as the heat-exchange target; a discharge-side temperature sensor that detects a discharge temperature of the refrigerant discharged by the compressor; and a controller that, when the controller determines that a rotation speed of the compressor is a maximum and the temperature of the heat-exchange target is lower than a preset temperature, controls an opening degree of the expansion valve by using the discharge temperature.

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Tokyo, Japan

Komei Nakajima