Mitsubishi Electric Corporation

Kazunori Korenaga

Takeshi Kuramochi

Hirofumi Horiuchi

Seiji Nakashima

Katsuyuki Yamamoto

Yoshio Yajima

An outdoor unit of an air-conditioning apparatus is provided with an outdoor heat exchanger configured to cause refrigerant that flows in the outdoor heat exchanger and air to exchange heat with each other, a plurality of outdoor fans each configured to rotate by driving of a motor and send air to the outdoor heat exchanger, and a controller configured to control the driving of the motor. When operation of one of the plurality of outdoor fans is stopped, the controller is configured to control the motor such that a rotation frequency of each of the plurality of outdoor fans that is in operation after operation of the one of the plurality of outdoor fans is stopped is higher than a rotation frequency of each of the plurality of outdoor fans that is in operation before operation of the one of the plurality of outdoor fans is stopped.

Outdoor unit of air-conditioning apparatus

A propeller fan includes a shaft part and a blade. The blade includes a basal part connected to the shaft part, a first part positioned either at the basal part or closer to an outer circumference of the propeller fan than is the basal part and away from the rotation axis by a distance r1, a second part positioned away from the rotation axis by a distance r2 that is longer than r1, a third part positioned away from the rotation axis by a distance r3 that is longer than or equal to r2, and a tip part positioned at an outer circumferential end of the blade and away from the rotation axis by a distance rt that is longer than r3. A relationship expressed as (&#x3b8;2&#x2212;&#x3b8;1)/(r2&#x2212;r1)&#x3e;(&#x3b8;t&#x2212;&#x3b8;3)/(rt&#x2212;r3)&#x2265;0 is satisfied.

Propeller fan and outdoor unit for air-conditioning apparatus

An air-conditioning apparatus includes: a refrigeration cycle; an injection circuit for connecting between an injection port and a branching portion arranged between an indoor expansion valve and a main circuit expansion valve; an injection circuit expansion valve arranged in the injection circuit; an internal heat exchanger for exchanging heat between refrigerant flowing between the branching portion and the main circuit expansion valve and refrigerant depressurized by the injection circuit expansion valve; and an outdoor unit control device, the outdoor unit control device being configured to control an opening degree A of the main circuit expansion valve so as to satisfy Relation A+C=B&#xd7;Gr, where A represents the opening degree of the main circuit expansion valve, C represents an opening degree of the injection circuit expansion valve, B represents a coefficient, and Gr represents a refrigerant circulating amount in the refrigeration cycle.

Air-conditioning apparatus

In an air-conditioning apparatus equipped with an outdoor unit having outdoor devices including a compressor that compresses a refrigerant, a flow switching valve that switches the flowing direction of the refrigerant, an outdoor heat exchanger that exchanges heat between the refrigerant and outdoor air, a first expansion valve that reduces the pressure of the refrigerant, an excess-refrigerant container that retains an excess refrigerant of the refrigerant, and a second expansion valve that reduces the pressure of the refrigerant; and an indoor unit having an indoor heat exchanger that exchanges heat between the refrigerant and indoor air, the air-conditioning apparatus includes an outdoor-heat-exchanger refrigerant injection port provided in a refrigerant pipe that is directly connected to the outdoor heat exchanger, and an excess-refrigerant-container refrigerant injection port provided in a refrigerant pipe that is directly connected to the excess-refrigerant container.

This invention relates to a multi-room air conditioning system with a plurality of indoor expansion valves. A method for sequencing the initialization of each indoor expansion valve upon system startup is disclosed. The method includes the following steps:

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Tokyo, Japan

Kazunori Korenaga