| 摘要 |
PURPOSE:To improve the condensing heat transfer efficiency of the captioned heat transfer pipe by a method wherein two groups of spiral grooves turning in opposite directions and rising sections separated from one another by the grooves are provided in the inner surface of the heat transfer pipe. CONSTITUTION:The two groups of spiral grooves 2 and 3 turning in opposite directions and the rising sections 4 separated from one another by the grooves are provided on the inner surface of the transfer pipe. The grooves 3 are made smaller in depth than the grooves 2 and the bottoms and the side walls of the grooves are kept constant with respect to the rising sections. Consequently, when the vapor of a liquid condenses on the inner wall of the heat transfer pipe 1, a film of the liquid is formed on each of the surfaces of the rising sections 4 and the liquid flows into the grooves 2 and 3 in the directions of gravity as shown by the arrows A and B to form itself a condensed liquid 5 so that the condensing heat transfer efficiency of the pipe is improved. |
