Mitsubishi Electric Corporation

Agc Inc.

Tomotaka Ishikawa

Takashi Ikeda

So Nomoto

Takeshi Sugimoto

Hiroshi Sata

Keisuke Takayama

Tetsuya Yamashita

Fumitake Unezaki

Yasutaka Ochiai

Yusuke Arii

Sangmu Lee

Ryo Tsukiyama

Kenichi Hata

Hajime Fujimoto

Abastari

Kousuke Tanaka

Keizo Fukuhara

Satoru Ue

Tomoya Fujimoto

Motoshi Hayasaka

Nobuya Ishihara

Takashi Umeki

A refrigeration cycle apparatus is a refrigeration cycle apparatus having a refrigerant circuit having a compressor, a condenser, a supercooler, an expansion device, and an evaporator connected by a refrigerant pipe, and configured to circulate refrigerant containing refrigerant having a temperature gradient, wherein the supercooler sets a degree of supercooling of the refrigerant, which is a temperature difference between a temperature from the condenser to a refrigerant flow inlet of the supercooler and a temperature in a refrigerant flow outlet on a downstream side of the supercooler, to be larger than the temperature gradient generated at a time of refrigerant shortage of the refrigerant between the refrigerant flow inlet and the refrigerant flow outlet of the supercooler, the refrigeration cycle apparatus including a refrigerant amount determination unit configured to compare a determination threshold value set to a value larger than the temperature gradient of the refrigerant with the degree of supercooling of the refrigerant, and determine whether or not there is a shortage of a refrigerant amount filled in the refrigerant circuit.

Refrigeration cycle apparatus and refrigeration apparatus

A refrigeration device includes a refrigerant circuit sequentially connecting a compressor, a condenser, a reservoir, and a subcooling coil via refrigerant pipes in series, an injection circuit configured to inject part of refrigerant flowing from the condenser to an intermediate pressure part of the compressor, and an injection expansion valve configured to reduce a pressure of refrigerant branched on a downstream side of the subcooling coil. The refrigeration device includes a temperature measurement unit, a pressure measurement unit, and a controller configured to identify a type of refrigerant on the basis of a measured value of the temperature measurement unit and a measured value of the pressure measurement unit, and control at least one of an operating frequency of the compressor, a rotation frequency of a condenser fan, and an opening degree of the injection expansion valve.

Refrigeration device and controller for refrigeration device

A refrigeration cycle apparatus includes: a low-stage refrigeration cycle including a low-stage compressor, a low-stage condenser, a low-stage pressure reducing device, and a low-stage evaporator, and circulating low-stage refrigerant; a high-stage refrigeration cycle including a high-stage compressor, a high-stage condenser, a high-stage pressure reducing device, and a high-stage evaporator, and circulating high-stage refrigerant; a cascade condenser exchanging heat between the low-stage refrigerant in the low-stage condenser and the high-stage refrigerant in the high-stage evaporator, and a controller. The low-stage refrigerant is a refrigerant that undergoes disproportionation. The low-stage refrigerant is maintained at a pressure lower than a disproportionation pressure at which the low-stage refrigerant undergoes disproportionation.

Refrigeration cycle apparatus and method for controlling refrigeration cycle apparatus

A refrigerating apparatus includes a high-temperature side circuit and a low-temperature side circuit connected to each other via a cascade condenser, a low-temperature side second flow control valve that turns a refrigerant, passing through a liquid pipe connecting between a cooling unit and other circuit parts in a low-temperature side circuit b, into a gas-liquid two-phase refrigerant, and an expansion tank connected to the suction side of a low-temperature circuit compressor via a tank electromagnetic valve.

Refrigerating apparatus

The refrigeration cycle apparatus includes: liquid-side connection piping that extends from liquid-side refrigerant piping; gas-side connection piping that extends from gas-side refrigerant piping; a refrigerant storage tank that stores refrigerant, an intake side thereof being connected to the liquid-side connection piping, and a discharge side thereof being connected to the gas-side connection piping; an inlet-side electromagnetic valve that is disposed on the liquid-side connection piping, and that is opened when there is no passage of electric current; an inlet-side check valve that is disposed on the liquid-side connection piping, and that allows the refrigerant to flow only toward the refrigerant storage tank; and a valve apparatus that is disposed on the gas-side connection piping, that is opened during passage of electric current to the inlet-side electromagnetic valve, and that is delayed before being shut off after passage of electric current to the inlet-side electromagnetic valve is stopped.

Refrigeration cycle apparatus

A two-stage refrigeration apparatus includes a high-stage refrigeration cycle including a high-stage-side refrigerant circuit including a high-stage-side compressor, high-stage-side condenser, high-stage-side expansion valve, and high-stage-side evaporator connected by pipes, a low-stage refrigeration cycle including a low-stage-side refrigerant circuit including a low-stage-side compressor, low-stage-side condenser, low-stage-side receiver, low-stage-side expansion valve, and low-stage-side evaporator connected by pipes, a cascade condenser including the high-stage-side evaporator and low-stage-side condenser, a receiver heat exchanging portion configured to cool the low-stage-side receiver, and a high-stage refrigeration cycle controller configured to perform controlling so as to activate the high-stage-side compressor when estimating a low-stage-side refrigerant will reach a supercritical state while the low-stage-side compressor is defrosted on the basis of the pressure of the low-stage-side refrigerant.

Binary refrigeration apparatus

An accumulator that is used in a refrigeration apparatus including a plurality of compressors and is provided for the plurality of compressors, the accumulator including an inlet pipe that penetrates a cylindrical container perpendicularly to a central axis of the cylindrical container and conveys gas-liquid mixed refrigerant into the container and a plurality of outlet pipes connected to respective suction sides of the plurality of compressors, wherein the plurality of outlet pipes each have one end located in the container and forming outlet port for conveying gas refrigerant in the container toward the plurality of compressors, and wherein the outlet port of each of the plurality of outlet pipes is concentrated in a central part of the container.

Accumulator and refrigeration apparatus including the same

A two-stage refrigeration apparatus includes a high-stage refrigeration cycle including a high-stage-side refrigerant circuit including a high-stage-side compressor, high-stage-side condenser, high-stage-side expansion valve, and high-stage-side evaporator connected by pipes, a low-stage refrigeration cycle including a low-stage-side refrigerant circuit including a low-stage-side compressor, low-stage-side condenser, low-stage-side receiver, low-stage-side expansion valve, and low-stage-side evaporator connected by pipes, a cascade condenser including the high-stage-side evaporator and low-stage-side condenser, a receiver heat exchanging portion configured to cool the low-stage-side receiver, and a high-stage refrigeration cycle controller configured to perform controlling so as to activate the high-stage-side compressor when estimating a low-stage-side refrigerant will reach a supercritical state when the low-stage-side compressor is inactive on the basis of the pressure of the low-stage-side refrigerant.

A heat exchanger includes a plurality of fins spaced apart from each other such that gas flows therebetween, and a plurality of heat transfer tubes extending through the plurality of fins and joined to the plurality of fins by tube expansion. The heat transfer tubes are arranged in five or more columns along a flow direction of the gas and staggered in a row direction intersecting the flow direction of the gas. Each of the plurality of fins is flat and plate-shaped and continuously extends between the heat transfer tubes in the flow direction of the gas. The plurality of heat transfer tubes satisfy relationships of 1.055D&#x2266;Da&#x2266;1.068D and 1.56Da&#x2266;L&#x2266;2.58Da, where D is an unexpanded outside diameter of the heat transfer tubes, Da is an expanded outside diameter thereof, and L is a distance between centers of adjacent two heat transfer tubes.

Heat exchanger, refrigeration cycle apparatus, and method of manufacturing heat exchanger

A refrigerating and air-conditioning apparatus performs, even during a heating operation under air conditions leading to formation of frost, a defrosting operation while simultaneously continuing the heating operation and improves comfort through heating by securing an appropriate amount of ventilation. A plurality of refrigeration cycles independently performs a heating operation and a defrosting operation. By controlling a ventilation damper of an indoor unit that is to perform a defrosting operation to increase the amount of ventilation, a prior ventilation operation for securing the time-averaged required amount of ventilation including the period in which the defrosting operation is being performed is performed before the defrosting operation, and after the prior ventilation is terminated, the defrosting operation is started.

Refrigerating and air-conditioning apparatus for use in a defrosting operation

A refrigerating and air-conditioning apparatus performs, even during a heating operation under air conditions leading to formation of frost, a defrosting operation while simultaneously continuing a heating operation and that improves comfort through heating by ensuring an appropriate amount of ventilation. A plurality of refrigeration cycles that are capable of independently performing a heating operation and a defrosting operation, are provided. A ventilation damper of an indoor unit in which a refrigeration cycle that performs a defrosting operation is installed is closed during a defrosting operation, and a ventilation damper of an indoor unit in which a refrigeration cycle that performs a heating operation is installed is controlled to achieve a required amount of ventilation corresponding to the indoor ventilation state.

A refrigerating and air-conditioning apparatus includes multiple refrigeration cycles each including a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger which are connected by a pipe, each refrigeration cycle being configured to be capable of performing a cooling operation and a heating operation, an outdoor fan configured to send air for heat exchange with the outdoor heat exchangers of the refrigeration cycles, multiple indoor fans arranged corresponding to the respective indoor heat exchangers of the refrigeration cycles, and a controller configured to defrost the outdoor heat exchanger of the at least one refrigeration cycle, control a rotation speed of the indoor fan corresponding to the refrigeration cycle performing the defrosting operation such that a temperature of air mixed by air-sending through the indoor fans reaches a predetermined temperature.

Apparatus for defrosting a plurality of heat exchangers having a common outdoor fan

A refrigerating device that forms a refrigerating cycle in which a plurality of outdoor machinesandprovided at least with compressorsand, condensersand, and accumulatorsandrespectively and an indoor machineprovided with decompressing meansand an evaporatorare connected in parallel by piping, having oil return pipesandthat return refrigerator oil stored in the accumulators into the compressors, an oil equalizing pipethat connects the accumulators to each other, and a controllerthat controls an operation of the compressor and on/off of an electromagnetic valvedeposed on the oil equalizing pipe.

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Tokyo, Japan

Tomotaka Ishikawa