HEAT TRANSFER PIPE WITH INNER SURFACE GROOVE

摘要

PROBLEM TO BE SOLVED: To provide a small diameter inner surface grooved heat transfer pipe in which condensation efficiency is improved by preventing a tip end of a fin from being covered with a heat medium fluid. SOLUTION: An inner surface grooved heat transfer pipe 1 is adapted such that many parallel spiral fins 2 are formed in the inner surface of a metal pipe. An outer diameter D of the heat transfer pipe is 3 to 6mm, a height H of each fin from a metal pipe inner peripheral surface is 0.15 to 0.20mm, a fin pitch P in the direction perpendicular to the longitudinal direction of the fin 2 is 0.23 to 0.39mm, a spiral angleαin the pipe axis direction of the fin is 9 to 16 degree, and an angleβformed between opposite side surfaces of each fin 2 is 10 to 20 degree.