| 摘要 |
PROBLEM TO BE SOLVED: To provide a boiling heat transfer tube having improved heat transfer performance by improving the wettability of refrigerant liquid to accelerate nuclear boiling, and to provide its manufacturing method. SOLUTION: On the outer peripheral face of a tube 2, fins 3 are formed by continuing spading and bending in such a manner that a spiral or annular cavity portion 31 is formed in the circumferential direction thereof. At the front ends of the fins 3, grooves 35 are formed with protruded portions 33 and recessed portions 34 by using a grooved roll for applying suppressing pressure. The grooves 35 have holes 32 at preset spaces in communication with the outside (refrigerant liquid). COPYRIGHT: (C)2005,JPO&NCIPI
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