Mitsubishi Electric Corporation

Kohei Kasai

Yohei Kato

Satoru Yanachi

Kimitaka Kadowaki

Hirokazu Minamisako

Shinichi Uchino

Tetsuji Saikusa

Tsubasa Tanda

Hiroaki Asanuma

Masazumi Chisaki

Tomoyoshi Obayashi

Takafumi Mito

A refrigeration cycle apparatus includes; an air heat exchanger; a first expansion valve; a water heat exchanger; a flow passage switching device provided to a discharge part of a compressor; an injection pipe branched from a branch portion of a refrigerant pipe connecting the water heat exchanger with the first expansion valve, and is connected to an injection port of the compressor; a second expansion valve provided to the injection pipe; and an internal heat exchanger configured to exchange heat between refrigerant flowing between the water heat exchanger and the branch portion and refrigerant flowing from the second expansion valve and the injection pipe. The branch portion is provided downstream of the internal heat exchanger and upstream of the first expansion valve in a flow direction of the refrigerant when the flow passage switching device is operated in the first state.

Refrigeration cycle apparatus

An air-conditioning apparatus includes a controller configured to control operations of an outdoor fan. The controller has a voltage acquisition unit configured to acquire drive voltages of the outdoor fan at set time intervals while the rotation speed of the outdoor fan is maintained at a reference rotation speed, a determination unit configured to determine whether or not an acquired drive voltage is equal to or greater than a lower limit threshold and less than an upper limit threshold, an extraction unit configured to calculate an evaluation value by extracting a drive voltage determined to be equal to or greater than the lower limit threshold and less than the upper limit threshold, and a defrosting determination unit configured to decide to defrost the outdoor heat exchanger if the calculated evaluation value is equal to or greater than an evaluation threshold.

Air-conditioning apparatus

A plate heat exchanger includes a plate stack including a plurality of heat transfer plates stacked with each other. Each of the heat transfer plates includes a heat medium inflow hole serving as an inlet for a heat medium, a heat medium outflow hole serving as an outlet for the heat medium, a refrigerant inflow hole serving as an inlet for refrigerant, and a refrigerant outflow portion located below the refrigerant inflow hole and serving as an outlet for the refrigerant. The heat transfer plates define heat medium passages, through each of which the heat medium flowing from the heat medium inflow hole flows, and refrigerant passages, through each of which the refrigerant flowing from the refrigerant inflow hole flows downward, arranged alternately with one another. Each of the heat medium passages and the refrigerant passages is defined between adjacent ones of the heat transfer plates.

Plate type heat exchanger and refrigeration cycle apparatus

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Tokyo, Japan

Kohei Kasai