最近,热交换器已进入了新的发展时期。为了进一步促进热交换器的多样化,提高经济效益,日本对传热管进行了如下研究: 1.采用特殊传热管:(1)螺旋管及纵轴管(见图1),前者沿轴向在管子的表面加工成螺旋波状;后者沿轴向在管子表面加工 Recently, heat exchangers have entered a new period of development. In order to further promote the diversification of heat exchangers and increase economic benefits, the following studies have been conducted on heat transfer tubes in Japan: 1. Adopt special heat transfer tubes: (1) spiral tube and vertical tube (see Fig. 1) Machined into a helical wavy form on the surface of the tube; the latter is machined axially on the surface of the tube