Mitsubishi Shindoh Co., Ltd.

The Japan Steel Works, Ltd.

501 Mitsubishi Shindoh Co., Ltd.

Mitsubishi Shindowh Co., Ltd.

Shunroku Sukumoda

Seizo Masukawa

Haruo Kohno

Masayoshi Takiura

Kohtaroh Nagahara

Takashi Iwamoto

Yoshio Abe

Yukio Sato

Takao Fukatami

Yasushi Owaki

Jun-Ichi Kumagai

Shin Kikuchi

Shinichi Ono

Masayuki Kawai

Tetsuya Furuuchi

Masashi Tomiie

Yoshikatsu Arayama

Makoto Miyauchi

Takashi Kazama

The fatigue resistance characteristics, particularly, fatigue resistance characteristics after retention at 150&#xb0; C. for 1000 hours are improved while maintaining the characteristics in the related art. Provided is a copper alloy sheet having a composition containing 0.2% by mass to 1.2% by mass of Mg, and 0.001% by mass to 0.2% by mass of P, the balance being Cu and unavoidable impurities. When X-ray diffraction intensity of a {110} crystal plane is set as I{110}, and X-ray diffraction intensity of {110} crystal plane of a pure copper standard powder is set as I{110}, a surface crystal orientation of the copper alloy sheet satisfies a relation of 4.0&#x2266;I{110}/I{110}&#x2266;6.0.

Cu-Mg-P-based copper alloy sheet having excellent fatigue resistance characteristic and method of producing the same

In a heat transfer pipe, annular grooves in a direction inclined at an angle of 45&deg; to 90&deg; with respect to an axis of the pipe are continuously formed at an interval in a longitudinal direction of the pipe. The annular grooves desirably have a groove depth of 0.20 mm or more, and a groove pitch of two to five times larger than the groove depth. Moreover, a ratio W/P of a bottom width W of projections of the grooves to the groove pitch P is desirably 0.1 to 0.9.

Heat transfer pipe for liquid medium having grooved inner surface and heat exchanger employing the same

With a grooved-inner-surface heat transfer tube, an inner circumferential surface of a metal tube is formed with fins bent at bent portions in a zigzag and extending consecutively around a circumferential direction of the inner circumferential surface, and at at least a part of the bent portions of the fins, the height of the fins is set at 30 to 90% of the height of the fins excluding the bend portions. With such a heat transfer tube, pressure loss can be suppressed while increasing heat exchange performance.

Heat exchange tube having a grooved inner surface

The present invention has the object of increasing the heat exchanging performance of heat transfer tubes having grooved inner surfaces. In order to achieve this object, the heat transfer tubes having grooved inner surfaces according to the present invention have fins which are formed consecutively in a circumferential direction on the inner surface of a metallic tube. The inner surface of the metallic tube is divided into regions R1.about.R4 in the circumferential direction. The inclination angle .alpha. with respect to the axis of the heat transfer tube of the fins 2 in odd-numbered regions when counting from one of the regions is 10.about.25.degree., and the inclination angle .beta. with respect to the axis of the heat transfer tube of the fins 2 in even-numbered regions when counting from the region is -10.about.-25.degree.. The pitch of the fins 2 is 0.3.about.0.4 mm, the height of the fins from the inner circumferential surface of the metallic tube is 0.15.about.0.30 mm, and the angle formed between the side surfaces of each fin is 10.about.25.degree..

Heat transfer tube having grooved inner surface

The present invention has the object of increasing the heat exchanging performance of heat transfer tubes having grooved inner surfaces. In order to achieve this object, the heat transfer tubes having grooved inner surfaces according to the present invention have fins which are formed consecutively in a circumferential direction on the inner surface of a metallic tube. The inner surface of the metallic tube is divided into regions R1.about.R4 in the circumferential direction. The inclination angle .alpha. with respect to the axis of the heat transfer tube of the fins 2 in odd-numbered regions when counting from one of the regions is 10.degree..about.25.degree., and the inclination angle .beta. with respect to the axis of the heat transfer tube of the fins 2 in even-numbered regions when counting from the region is -10.degree..about.-25.degree.. The pitch of the fins 2 is 0.3.about.0.4 mm, the height of the fins from the inner circumferential surface of the metallic tube is 0.15.about.0.30 mm, and the angle formed between the side surfaces of each fin is 10.degree..about.25.degree..

The object of the present invention is to offer a heat transfer tube having a grooved inner surface, wherein the side edges of the board material do not form a waved shape and cracks do not form during tube expansion. In order to achieve this object, the grooved-inner-surface heat transfer tube of the present invention has a metallic tube with an inner circumferential surface, on which are formed a weld portion which extends in an axial direction of this metallic tube, a pair of projecting strip portions formed parallel to and separate from this weld portion, and a plurality of fins formed in an area between these projecting strip portions. The fins are formed with a constant angle with respect to the tube axis, and the ends of these fins are connected with the projecting strip portions. The thickness of the metallic tube within the grooves formed between the fins is made to increase in approaching the weld portion within an area surrounding the weld portion wherein the central angle is within 30.degree..about.90.degree. on both sides from the center of the weld portion.

Heat transfer tube having grooved inner surface and production method

The heat transfer tube of the present invention is provided in an inner surface thereof with a plurality of main grooves and a plurality of narrow grooves. The main grooves have rectangular shaped cross sections, parallel to one another, and extend at an angle to the longitudinal direction of the heat transfer tube. The narrow grooves are formed parallel to one another, extend independently of the main grooves. Each of the narrow grooves has a bottom face and a pair of side faces, the side faces are inclined closely toward the bottom face, and each of the side faces and a part of the bottom face form sharp cuts.

Heat transfer tubes and method for manufacturing

A heat transfer tube having an inner surface in which are formed primary grooves and secondary grooves. The primary grooves parallel to one another, extending at an angle to the longitudinal direction of the heat transfer tube and secondary grooves parallel to one another, extending an angle to the primary grooves. At the intersections of the primary and secondary grooves is formed a series of pear-shaped grooves whose inner opening dimension is smaller than the dimension of the bottom of the pear-shaped groove.

Growing community of inventors

Aizuwakamatsu, Japan

Shunroku Sukumoda