Mitsubishi Electric Corporation

Hiroki Washiyama

Yuji Motomura

Naofumi Takenaka

Kimitaka Kadowaki

Koji Furuya

Hiroki Takahashi

Jun Nishio

Sara Tsujimoto

Koji Azuma

Soshi Ikeda

Kosuke Miyawaki

Yuki Mizuno

Ryosuke Matsui

Kazuya Honda

Yuji Tarumi

Kenshiro Kawabata

Shoichi Hirano

Shota Shirai

Hiroaki Kobata

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

The heat-medium cycle circuit includes a discharge mechanism including a discharge valve, the discharge mechanism being configured to, when the discharge valve is open, discharge air present inside the heat-medium cycle circuit to the outside of the heat-medium cycle circuit. The air-conditioning apparatus is configured to execute an air discharge operation mode in which the air present inside the heat-medium cycle circuit is discharged to the outside of the heat-medium cycle circuit. The air discharge operation mode includes a first operation mode, and a second operation mode performed after the first operation mode. The first operation mode is an operation mode in which, with the discharge valve being closed, an operation similar to a cooling operation is performed. The second operation mode is an operation mode in which, with the discharge valve being open, an operation similar to a heating operation is performed.

Air-conditioning apparatus, and air discharge method for air-conditioning apparatus

An air-conditioning apparatus includes an outdoor unit, multiple indoor units, and an intermediate unit. The indoor units each include a flow control device and an indoor controller. The intermediate unit includes an intermediate heat exchanger, a circulation device, and an intermediate controller. When at least one indoor unit starts operating, the intermediate controller determines whether a flow rate of a heat medium flowing into the intermediate heat exchanger is greater than or equal to a minimum flow rate. In response to determining that the flow rate is less than the minimum flow rate, the intermediate controller transmits an open instruction signal, representing an instruction to increase the opening degree of the flow control device, to the indoor controller of the indoor unit that is in a non-operation state. The indoor controller increases the opening degree of the flow control device in response to the received open instruction signal.

Air-conditioning apparatus

Distribution controller for air conditioner

An air-conditioning apparatus includes a low-pressure-side pressure sensor that detects the pressure of heat-source-side refrigerant that flows into a compressor and outputs it as a first detection value and a high-pressure-side pressure sensor that detects the pressure of heat-source-side refrigerant discharged from the compressor and outputs it as a second detection value. When switching the operation mode of the apparatus, a controller determines whether the ratio of the first detection value to the second detection value is higher than a first threshold. When the ratio is higher than the threshold, the controller causes a second refrigerant flow switching device to perform a switching operation. When the ratio is less than or equal to the threshold, the controller makes an adjustment such that an opening degree of an expansion device is less than a second threshold, and then causes the second refrigerant flow switching device to perform the switching operation.

A heat medium relay device includes a valve block provided in a third space, and including a plurality of valves to allow a secondary heat medium subjected to the heat exchange at a first heat exchanger and a secondary heat medium subjected to the heat exchange at a second heat exchanger to flow to at least one indoor unit, the valve block being lighter in weight than each of the first heat exchanger, a first pump, the second heat exchanger, and a second pump.

Heat medium relay device

A relay unit includes: a heat medium heat exchanger; a casing; a first refrigerant pipe connection port connected to one of two refrigerant pipes through which refrigerant circulates between the heat medium heat exchanger and the heat source side unit; a second refrigerant pipe connection port connected to an other of the refrigerant pipes; a first heat medium pipe connection port connected to one of two heat medium pipes through which a heat medium circulates between the heat medium heat exchanger and the load side unit; and a second heat medium pipe connection port connected to an other of the heat medium pipes. The first refrigerant pipe connection port, the second refrigerant pipe connection port, the first heat medium pipe connection port, and the second heat medium pipe connection port are provided on a top surface of the casing and face in a direction opposite to a direction of gravity.

Relay unit and air-conditioning apparatus including the same

An air-conditioning apparatus includes outdoor units each including a compressor and outdoor heat exchanger, refrigerant flowing through the outdoor units; an indoor unit including an indoor heat exchanger, a heat medium flowing through the indoor unit; relay devices to which the outdoor units are connected, and to which the indoor unit is connected, each relay device includes a heat medium heat exchanger that exchanges heat between the refrigerant and the heat medium; and a controller. The controller controls action of the outdoor units, the indoor unit, and the relay devices. The controller determines necessity for a defrosting operation; responsive the defrosting operation being necessary, compares an indoor unit total load with an outdoor unit total capacity; and controls an operating frequency of the compressor of an outdoor unit other than the outdoor unit on which the defrosting operation is to be performed to increase the outdoor unit total capacity.

Air-conditioning apparatus with simultaneous heating and defrosting modes

An air-conditioning apparatus includes: a heat-medium transfer device including a pump provided to transfer a heat medium that contains water or brine and transfers heat; a plurality of indoor units each of which includes an indoor heat exchanger provided to cause heat exchange to be performed between indoor air and the heat medium, and a flow control valve provided to adjust a flow rate of the heat medium that flows through the indoor heat exchanger, the plurality of indoor units being connected to the heat-medium transfer device by respective heat medium pipes; and a controller provided to control an opening degree of the flow control valve. The controller determines a valve opening-degree control range that is a control range of an opening degree of the flow control valve of each indoor unit, based on a flow-passage resistance depending on a length of a pipe that extends from the heat-medium transfer device to the indoor unit, such that the lower the flow-passage resistance, the smaller the valve opening-degree control range.

An air-conditioning system includes a plurality of indoor units; a relay unit including an intermediate heat exchanger configured to exchange heat between refrigerant and a heat medium; and a heat source unit configured to supply cooling energy or heating energy to each of the plurality of indoor units via the relay unit. The heat source unit and the relay unit are connected by a heat-source connection pipe through which the refrigerant flows, and the relay unit and the plurality of indoor units are connected by a load connection pipe through which the heat medium flows. The load connection pipe comprises a main pipe connecting between the relay unit and one of the indoor units provided at an end of the load connection pipe opposite to the relay unit. The main pipe has branch parts associated with the indoor units.

Air-conditioning system

An air-conditioning system includes a heat-source device that includes a compressor and a heat-source-side heat exchanger, a relay device that includes a pump and an intermediate heat exchanger, and a plurality of indoor units that each include a load-side heat exchanger. The air-conditioning system includes a refrigerant circuit through which refrigerant circulates and a heat medium circuit through which a heat medium circulates. The air-conditioning system includes a flow rate detection unit configured to detect flow rate information associated with a flow rate of a heat medium that flows through each of the plurality of indoor units and a controller configured to control the compressor and the pump. The controller controls operation of at least either the compressor or the pump on the basis of the flow rate information detected by the flow rate detection unit.

Growing community of inventors

Tokyo, Japan

Hiroki Washiyama