| 摘要 |
PROBLEM TO BE SOLVED: To improve the inner structure of a kind of heat-exchanger tube to enhance performance compared with a known tube. SOLUTION: Integrated inner fins of heights H are extended circumferential-directionally in a tube inner face consecutively in parallel to an axial line or a thread line at a torsion angleβ1 when measured along a tube-axial direction, to form a primary groove, the inner fins are crossed with secondary grooves with a space between each other over the whole tube circumference, the second groove has a cut-in depth T2 and a groove opening angleα2, in parallel each other, at a torsion angleβ2 when measured along the tube-axial direction, the inner fins and the secondary groove are crossed with tertiary grooves with a space between each other over the whole tube circumference, and the tertiary grooves are consecutively extended circumferential-directionally in parallel each other at a torsion angleβ3 when measured along the tube-axial direction, and has a cut-in depth T3 and a groove opening angleα3. COPYRIGHT: (C)2007,JPO&INPIT |
