| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to improve the heat transfer performance by improving the metallurgical bondability with porous metal and to improve the structural normality by setting the charging ratio of porous metal in a gap between an outer tube and an inner tube to a predetermined range. SOLUTION: As shown, a double heat transfer tube 2 for a vapor generator comprises an outer tube 3, an inner tube 5 disposed at a predetermined gap at the inner peripheral side of the tube 3, and a porous metal 4 disposed in the gap between the tubes 3 and 5. The tube 2 for the generator has leakage detecting means for detecting the leakage of fluid flowing through the hole 2 via the gap between the tubes 3 and 5, and further sets the charging ratio of the metal 4 in the gap between the tubes 3 and 5 to a range of 70 to 95%. Thus, since both the heat transfer performance and leakage detecting performance satisfy the designing request, high reliability is secured, the metallurgical bondability between the tubes 5, 3 and the metal 4 is improved to make it possible to improve the heat transfer performance. |
