Daikin Industries, Ltd.

Junichirou Tanaka

Shigeharu Taira

Haruo Nakata

Hiromune Matsuoka

Masaaki Kitazawa

Isao Fujinami

Mamoru Asakawa

Koji Shibaike

A pipe joint and a method of joining pipes using the pipe joint prevent loss of a sleeve, enhance workability in the pipe joining operation, and ensure sealing performance. The pipe joint may be utilized in a refrigerant device, a heat pump hot water supply device, a closing valve and a water supply piping. The method for connecting piping may be used in an in-the filed piping method. The pipe joint includes a joint body, a fastening member such as a nut, and a sleeve. The sleeve is integrated with the fastening member or the joint body before the fastening member is attached to the joint body. When the fastening member is attached to the joint body, the sleeve is cut off and separated from the fastening member or joint body. When the nut is fully attached, the sleeve bites into the pipe, and the pipe is joined to the joint body.

Pipe joint, refrigeration device, heat pump hot water supply device, closing valve, water supply piping, method of connecting piping, and in-the field piping method

A joint includes a joint main body, a sleeve and a nut. The joint main body has a joining hole and an external threaded part. The nut is threaded onto the external threaded part in a threaded state in which the pipe and the sleeve are inserted through the joining hole. The nut joins the pipe to the joining hole via the sleeve. The sleeve is tightly fitted to the pipe and the joining hole by the threading of the nut to induce deformation that expands radially outward. The deformation prevents insertion of the sleeve into the joining hole to a specific position in an unthreaded state in which the pipe and the sleeve have been pulled out from the joining hole.

Pipe joint

A method for refrigerant and oil collecting operation capable of assuring the cleanliness of the inside of an existing communication pipe at a low cost and installing, at a low cost, a new air conditioner, comprising a compressor (), a heat source side heat exchanger (), a decompressing mechanism (), and a user side heat exchanger (), comprising the steps of performing a pipe heating operation in a heating operation mode and performing a refrigerant and oil collecting operation to collect refrigerant to a heat source side heat exchanger (), namely, with the refrigerant heated to a temperature higher than that where contaminants such as refrigerator oil inside a refrigerant circuit is dissolved into the refrigerant, performing the refrigerant and oil collecting operation so as to assure the cleanliness of the inside of the existing communication pipes ().

Method for refrigerant and oil collecting operation and refrigerant and oil collection controller

A refrigerating device has a refrigerant circuit having a compressor ( ), an indoor heat exchanger ( ), a main motor operated valve (EV ), and an indoor heat exchanger ( ) connected in a loop, and uses, as a working medium, an R32 refrigerant or a mixed refrigerant containing R32 at at least 70 wt %. A supercooling heat exchanger ( ) is disposed between the indoor heat exchanger ( ) and the main motor operated valve (EV ), and the liquid side of the refrigerant circuit are connected to the gas side by by-pass pipes ( ) through the supercooling heat exchanger ( ). A supercooling motor operated valve (EV ) is disposed at the by-pass pipe ( ) upstream of the supercooling heat exchanger ( ). A discharge temperature detected by a discharge temperature sensor ( ) is determined by a discharge temperature determination part ( ), and based on the determination result, the opening of the supercooling motor operated valve (EV ) is controlled so as to control an amount of the refrigerant flowing through the by-pass pipes ( ), whereby, using the working medium containing R32, the discharge temperature of the compressor is optimized without reducing the efficiency, and the COP and reliability are improved.

Refrigerating device

A flow merging and dividing device, wherein two refrigerant flows move from two inlets ( ) located at an inlet part ( ) into a merging part ( ) for merging, the drift of the two refrigerant flows is eliminated by the merging of the flows at the merging part ( ), and the refrigerant flows in which the drift is eliminated by the merging of the flows at the merging part ( ) flows out from three outlets ( ) located at an outlet part ( ), whereby two refrigerant flows can be discharged as three refrigerant flows again from the three outlets ( ) after two refrigerant flows are merged so as to eliminate the drift of the two refrigerant flows.

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Kusatsu, Japan

Junichirou Tanaka