HEAT TRANSFER PIPE WITH INNER FACE GROOVE AND MANUFACTURE OF THE SAME

摘要

PROBLEM TO BE SOLVED: To promote refrigerant boiling and refrigerant stirring by changing fin pattern regularly along a circumferential direction and a lengthwise direction of a pipe and providing either one of a network cross-fin part, a strip fin part and a strip flat part in the lengthwise direction of the pipe. SOLUTION: A fin pattern comprises an inclined fin part 10 and a network cross-fin part 20 and the inclined fin part 10 is formed in such a manner that fins 11 are arranged with lead angles ofβ1 andβ2 regularly and alternately changed one after another at a predetermined pitch P1 in a circumferential direction of a pipe and the network cross-fin part 20 is formed in an alignment with the circumferential direction. A pitch P2 is formed by the inclined fin part 10 and the network cross-fin part 20. Refrigerant flowing from the inclined fin part 10 causes turbulent flow to promote boiling so that heat transfer characteristic is enhanced. This network cross-fin part promotes boiling of the refrigerant and the strip fin part and the strip flat part enhance refrigerant stirring further.