Mitsubishi Electric Corporation

Oki Electric Industry Co., Ltd.

Katsuhiro Ishimura

Koji Yamashita

Naofumi Takenaka

Shinichi Wakamoto

Soshi Ikeda

Yuji Motomura

Hiroyuki Morimoto

Jun Nishio

Takeshi Hatomura

Takuya Matsuda

Makoto Wada

Kosuke Tanaka

Kazuya Honda

Yuki Mizuno

Shusei Aoki

Kohei Ogura

Akira Sasaki

Osamu Morimoto

Hiroyuki Okano

Fumihiko Ishizono

Naomichi Tamura

Raito Kawamura

Mikiya Suzuki

Hiroaki Asanuma

Hideto Nakao

Mitsuru Kawashima

Shigeru Shikii

Hiroshi Takamoto

Hirokazu Ishimatsu

Naomi Oohashi

Seiji Inoue

Kazuro Takeda

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 refrigerant circuit in which a compressor, a refrigerant flow switching device, a heat source side heat exchanger, an expansion device, a heat medium heat exchanger, and an accumulator are connected, a heat medium circuit in which a pump, the heat medium heat exchanger, a heat medium flow control device, and a load side heat exchanger are connected, at least one or more bypass pipes provided in the refrigerant circuit so that the refrigerant discharged from the compressor bypasses at least either one of the heat source side heat exchanger and the heat medium heat exchanger, a bypass opening and closing device provided at the bypass pipe, and a controller configured to control the bypass opening and closing device to carry out a start-up control function of causing low-pressure gas refrigerant with a high degree of superheat to flow into the accumulator.

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 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

When a refrigerant leakage sensor detects a leakage of refrigerant from a refrigeration cycle apparatus having an indoor unit and an outdoor unit, a refrigerant recovery operation is started. In the refrigerant recovery operation, refrigerant is recovered in an accumulator and afterward a pump down operation is performed. In recovery of refrigerant in the accumulator, refrigerant in a liquid phase is accumulated in the accumulator as a result of circulation of refrigerant by operating a compressor in the state where a liquid shut-off valve and a gas shut-off valve are opened. After recovery of refrigerant in the accumulator is ended, the refrigerant in a liquid phase is accumulated in an outdoor heat exchanger by the pump down operation for operating the compressor in the state where the liquid shut-off valve is closed.

Refrigeration cycle apparatus

Upon detection of a leakage of refrigerant, a refrigerant recovery operation is performed for operating a compressor in a state where an outdoor expansion valve is closed. The refrigerant suctioned from an indoor unit passes through an outdoor heat exchanger so as to be liquefied and accumulated in an outdoor unit. When a low-pressure detection value by a pressure sensor decreases below a reference value, a termination condition for the refrigerant recovery operation is satisfied, and the compressor is stopped. Furthermore, when an abnormality in the refrigerant recovery operation is detected based on a behavior of the low-pressure detection value obtained until the termination condition is satisfied, the compressor is stopped to thereby end the refrigerant recovery operation. Also, guidance information for notification about an abnormality is output to a user.

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 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

An air conditioner that includes a refrigerant circuit connecting a plurality of indoor heat exchangers in parallel and is able to complete collection of refrigerant to the side of an outdoor heat exchanger in a shorter time when the refrigerant has leaked at any indoor heat exchanger is provided. Thus, in the air conditioner according to the present invention, when refrigerant leak is detected by a refrigerant leak sensor provided in an indoor unit and refrigerant leak is not detected by a refrigerant leak sensor provided in an indoor unit, an indoor LEV and a cutoff valve are closed to isolate an indoor heat exchanger of the indoor unit from the refrigerant circuit in a refrigerant pump-down operation. When refrigerant leak is detected by the refrigerant leak sensor and refrigerant leak is not detected by the refrigerant leak sensor, an indoor LEV and a cutoff valve are closed.

Air conditioner

An air-conditioning apparatus includes a refrigerant circuit in which a compressor, a heat source heat exchanger, an expansion device, and a load heat exchanger are connected via refrigerant pipes; a refrigerant leakage sensor configured to output a refrigerant leakage detection signal indicating detection of refrigerant leakage when the refrigerant leakage sensor detects the refrigerant leakage; a refrigerant leakage cutoff device configured to cut off a flow of refrigerant when the refrigerant leakage cutoff device is set to a closed state; and a controller configured to determine whether refrigerant leakage occurs on the basis of an operating state and whether the refrigerant leakage detection signal is received from the refrigerant leakage sensor. When the controller receives the refrigerant leakage detection signal and determines, on the basis of the operating state, that the refrigerant leakage occurs, the controller is configured to set the refrigerant leakage cutoff device to the closed state.

Air-conditioning apparatus and air-conditioning system

A refrigeration cycle apparatus includes a gas leakage sensor and a control device. When refrigerant leakage is detected by the gas leakage sensor, the control device performs a first mode operation to operate a compressor in such a state that a four-way valve is set to a cooling operation state, an expansion valve is opened, and a first shutoff valve is closed. After performing the first mode operation, the control device performs a second mode operation to operate the compressor in such a state that the four-way valve is set to a heating operation state and the first shutoff valve is closed.

Heat pump with refrigerant leak detection and pump-down method

A space in which an indoor unit is disposed has its corresponding refrigerant leakage sensor. A remote control for the indoor unit has its corresponding information output device for notifying the user of information visually and/or aurally. When the refrigerant leakage sensor detects a leakage of refrigerant, an alarm outputs a warning sound and a safety measure device is activated. Further, the information output device outputs guidance information for notifying the user action to be taken after the safety measure device takes the safety measure. After outputting the guidance information, the information output device stops outputting the guidance information in response to completion of the user action.

A storage device of a system control device stores grouping information that defines an association among a refrigerant sensor, a plurality of indoor units, at least one outdoor unit, and a plurality of refrigerant leakage suppression devices. When refrigerant leakage is detected by the refrigerant sensor, the system control device performs a process for specifying, from the plurality of indoor units, an indoor unit in which the refrigerant leakage has occurred. Further, the system control device makes reference to the grouping information to operate a refrigerant leakage suppression device corresponding to the indoor unit specified by performing the above-described process.

Air conditioning system

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.

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Tokyo, Japan

Katsuhiro Ishimura