Mitsubishi Electric Corporation

Soshi Ikeda

Jun Nishio

Naofumi Takenaka

Yuji Motomura

Koji Yamashita

Kosuke Tanaka

Hiroyuki Morimoto

Katsuhiro Ishimura

Shinichi Wakamoto

Takeshi Hatomura

Yuki Mizuno

Hideto Nakao

Kazuya Watanabe

Osamu Morimoto

Hiroki Washiyama

Kosuke Miyawaki

Shohei Ishimura

Masakazu Sato

Yusuke Tashiro

Susumu Yoshimura

Mizuo Sakai

Keisuke Hokazono

Raito Kawamura

Shinichi Uchino

Kazuya Honda

Kohei Ogura

Masakazu Kondo

Atsushi Kawashima

Hiroki Okazawa

Yasuhide Hayamaru

Hiroaki Nakamune

Koji Furuya

A refrigeration cycle apparatus includes a main circuit and a bypass circuit. The main circuit includes: a compressor; a first condenser; a first refrigerant-to-refrigerant heat exchanger; a first expansion device; a first branching portion; a first evaporator; a third branching; and a fourth branching portion. The bypass includes: a second expansion device; the first refrigerant-to-refrigerant heat exchanger; and a second branching portion. The second branching portion includes a liquid outflow pipe and a gas outflow pipe. The liquid outflow pipe defines one outlet for the refrigerant and is located below the gas outflow pipe. The gas outflow pipe defines another outlet for the refrigerant and is located above the liquid outflow pipe. The one outlet of the second branching portion communicates with the third branching portion. The other outlet of the second branching portion communicates with the fourth branching portion.

Refrigeration cycle apparatus

A refrigeration cycle device with a main circuit, a bypass circuit and a supercooling heat exchanger further includes: a controller to control an opening degree of the bypass expansion valve; a first sensor to detect a temperature at the refrigerant inflow side of the evaporator; and a second sensor to detect a pressure of the non-azeotropic mixed refrigerant flowing from the evaporator, wherein the controller controls the opening degree of the bypass expansion valve using temperatures of the evaporator, that is, the temperature at the refrigerant inflow side and a saturated gas temperature of the non-azeotropic mixed refrigerant calculated from the pressure so as to adjust a flow rate of the non-azeotropic mixed refrigerant flowing into the evaporator, to eliminate the temperature difference in the evaporator for suppressing uneven frost formation on the evaporator, and thus to prevent heat exchange performance from degrading.

Refrigeration cycle device

An air-conditioning apparatus includes: a heat source unit that generates a heating energy or a cooling energy that is transferred to refrigerant; a heat-use unit that causes the refrigerant to transfer the heating energy or the cooling energy to a heat load through heat exchange between the refrigerant and the heat load; a plurality of return pipes arranged parallel to each other and connecting the heat source unit and the heat-use unit to allow the refrigerant to flow therein from the heat-use unit to the heat source unit; an opening and closing device provided at at least one of the return pipes to control a flow rate of refrigerant; and a controller that opens the opening and closing device in a cooling operation, and closes the opening and closing device in a heating operation.

Air-conditioning apparatus

An air-conditioning apparatus includes: a heat source-side system having an intermediate heat exchanger that causes heat exchange to be performed between a heat source-side heat medium and a use-side heat medium, causes the heat source-side heat medium to receive or transfer heat, and causes the use-side heat medium to undergo a phase change; and a use-side cycle circuit formed of pipes connecting, to one another, the intermediate heat exchanger, a pump that sucks and delivers the use-side heat medium in a liquid state, a use-side heat exchanger that heats or cools air in an air-conditioning target space due to heat exchange causing a change in phase of the use-side heat medium, and a pressure-reducing device that reduces a pressure of the use-side heat medium that passes through the use-side heat exchanger, the use-side cycle circuit causing the use-side heat medium to circulate through the use-side cycle circuit.

An air-conditioning apparatus includes a main circuit in which a compressor, a flow switching device, an indoor heat exchanger, a pressure reducing device, and a plurality of parallel heat exchangers connected in parallel with each other are connected by pipes, a bypass pipe, a flow control device provided to the bypass pipe and configured to adjust a flow rate of refrigerant flowing through the bypass pipe, an evaporating pressure sensor configured to measure an evaporating pressure of the refrigerant, and a controller. The air-conditioning apparatus is configured to operate in a normal heating operation mode and a heating-defrosting operation mode. When an operation associated with the normal heating operation mode is switched to an operation associated with the heating-defrosting operation mode, the controller adjusts an opening degree of the flow control device using the evaporating pressure in the parallel heat exchanger and a driving frequency of the compressor.

An air-conditioning apparatus includes a primary-side circuit in which a compressor, a first flow switching device, an outdoor heat exchanger, a second flow switching device, a first expansion device, and a relay heat exchanger are connected by pipes and in which refrigerant circulates; a secondary-side circuit in which the relay heat exchanger, a pump, a plurality of indoor heat exchangers, and heat medium flow control devices are connected by pipes and in which a heat medium circulates; and a controller configured to control the first and second flow switching devices such that in cooling and heating operations, the refrigerant and a heat-source-side fluid flow through the outdoor heat exchanger in opposite directions and the refrigerant flows through the relay heat exchanger in a constant direction. The pump is installed such that the heat medium, the refrigerant flow, and air for an air-conditioning target space flow in particular directions.

An air-conditioning apparatus includes: a heat-source-side device that heats or cools a heat medium; a pump that sucks and transfers the heat medium; use-side heat exchangers; a heat medium circuit; flow rate control devices; indoor-side pressure sensors; a pump inlet-side pressure sensor and/or a pump outlet-side pressure sensor; a flow rate detection device that detects a pump flow rate; and a controller that performs a first operation in which the flow rate control devices are individually opened or closed and data regarding a flow passage resistance at a path related to each of the heat exchangers is obtained, and a second operation in which heat is supplied to indoor air, and calculates calculate flow rates of the heat medium that flows through the heat exchangers in the second operation, from pump flow rates and pressures detected by the pressure sensors in the first and second operations.

Air-conditioning apparatus and heat-medium flow-rate calculation method

An air-conditioning apparatus includes a refrigeration circuit, a first shut-off device, a leakage detection device, and a controller configured to perform a refrigerant recovery operation in a case where refrigerant leakage is detected. At the time of the refrigerant recovery operation, the controller performs control to perform a first operation of recovering refrigerant from a load-side heat exchanger into an accumulator and a heat-source-side heat exchanger, and a second operation of moving refrigerant in the heat-source-side heat exchanger to the accumulator. In the first operation, the first shut-off device is closed, a flow passage switching device is brought into a first connection state, and a compressor is driven. The second operation is performed after the first operation, and in the second operation, the connection state of the flow passage switching device is switched to a second connection state in a state where the compressor is being operated.

An air-conditioning apparatus includes a main circuit in which a compressor, a load side heat exchanger, a first pressure reducing device, and a plurality of parallel heat exchangers connected in parallel with each other are connected by pipes, a bypass pipe diverting a portion of refrigerant discharged by the compressor, a flow switching unit connecting a parallel heat exchanger to be defrosted to the bypass pipe, a plurality of flow rate control devices controlling flow rates of refrigerant flowing through the plurality of parallel heat exchangers, and a controller which controls, in the heating-defrosting operation mode or in the heating operation mode after execution of the heating-defrosting operation mode, the flow rate control devices to control, in accordance with a frost state of a parallel heat exchanger functioning as an evaporator among the plurality of parallel heat exchangers, the flow rate of refrigerant flowing through the parallel heat exchanger.

Air-conditioning apparatus having heating-defrosting operation mode

An air-conditioning apparatus includes a refrigeration circuit, a first shut-off device provided at a pipe connecting a heat-source-side heat exchanger and an expansion device, a refrigerant leak detection device, and a controller. The controller controls a flow switching device to switch a connection state between a first connection state in which a discharge side of a compressor is connected to the heat-source-side heat exchanger, and a second connection state in which a suction side of the compressor is connected to the heat-source-side heat exchanger via an accumulator. When a refrigerant leak is detected, the controller performs a refrigerant retrieval operation and a refrigerant transfer operation.

Air-conditioning apparatus with leak detection control

A compressor of an air-conditioning device includes a scroll mechanism unit having a fixed scroll and an orbiting scroll that cooperates with the fixed scroll to compress refrigerant. There is a first space portion provided between the scroll mechanism unit and an electric motion unit; an annular second space portion provided in a circumference of the scroll mechanism unit in a radial direction; a communication path provided between the first space portion and the second space portion, to guide, to the second space portion, the refrigerant sucked from the suction pipe to the first space portion. A part of the refrigerant between the first expansion valve and the second expansion valve is injected simultaneously to the first space portion and the second space portion.

Air-conditioning device

An air-conditioning apparatus includes a refrigerant circuit in which pipes sequentially connect a compressor, a flow switching device, a heat source side heat exchanger, an expansion device, a load side heat exchanger, and the flow switching device, and configured to perform a cooling operation and a heating operation switched by the flow switching device, an oil separator configured to separate refrigerating machine oil from refrigerant discharged from the compressor, a first bypass passage in which fluid flowing out of the oil separator flows, an auxiliary heat exchanger configured to cool the fluid, a first flow control device configured to control passing of the fluid, a second bypass passage in which liquid refrigerant or two-phase gas-liquid refrigerant flowing through one of the pipes connecting the heat source side heat exchanger and the expansion device flows, and a second flow control device configured to control passing of refrigerant.

An air-conditioning apparatus includes a refrigeration cycle circulating refrigerant and connecting a compressor, a heat-source-side heat exchanger, one or more of load-side expansion devices, and one or more of load-side heat exchangers by refrigerant pipes, a bypass having one end connected to a discharge side of the compressor of the refrigeration cycle and the other end connected to a suction side of the compressor of the refrigeration cycle to bypass a portion of the refrigerant discharged from the compressor, a first expansion device depressurizing the refrigerant flowing through the bypass, an auxiliary heat exchanger cooling the refrigerant depressurized at the first expansion device, a second expansion device controlling a flow rate of the refrigerant flowing from the auxiliary heat exchanger to the suction side of the compressor, and a controller controlling an opening degree of the second expansion device.

An air-conditioning apparatus includes a bypass pipe that has one end connected to the discharge side of a compressor and through which refrigerant exiting the compressor flows, an auxiliary heat exchanger that is connected to the other end of the bypass pipe and the suction part of the compressor, and cools refrigerant flowing through the bypass pipe and supplies the cooled refrigerant to the suction part of the compressor, and a flow regulating unit that is provided on the refrigerant outlet side of the auxiliary heat exchanger, and regulates the flow rate of refrigerant routed into the suction part of the compressor from the auxiliary heat exchanger.

Heat pump with an auxiliary heat exchanger for compressor discharge temperature control

An air-conditioning apparatus includes a refrigerant circuit formed by connecting, with pipes, a compressor to compress refrigerant and discharge the compressed refrigerant, a first heat exchanger, a subcooling heat exchanger exchanges heat between a portion of the refrigerant flowing in a first flow passage and another portion of the refrigerant flowing in a second flow passage to subcool the portion of refrigerant flowing in the first flow passage, a first expansion device to decompress the refrigerant, a second heat exchanger, and an accumulator connected to a suction side of the compressor and configured to store excess refrigerant, so that the refrigerant is circulated through the refrigerant circuit. The air-conditioning apparatus is configured to prevent the discharge temperature of the compressor from being excessively increased irrespective of the operation mode and therefore prevent damage to the compressor.

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Chiyoda-ku, Japan

Soshi Ikeda