Wärmeübertragungsrohr mit einer gerillten Innenfläche

摘要

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 DIFFERENCE 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 DIFFERENCE 25 DEG , 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 DIFFERENCE -25 DEG . The pitch of the fins 2 is 0.3 DIFFERENCE 0.4 mm, the height of the fins from the inner circumferential surface of the metallic tube is 0.15 DIFFERENCE 0.30 mm, and the angle formed between the side surfaces of each fin is 10 DIFFERENCE 25 DEG .