| 摘要 |
Improved externally finned metal heat transfer tube has multiple-start helical ridging on its inner surface which conforms to a range of values of a disclosed equation relating the size and shape of the ridging to its pitch and to the inner diameter of the tube. The inside tube wall profile, in axial section, is defined by a straight line interrupted by the internal ridges. The ridge tips are connected to the straight line segments of the profile by convex and concave portions which meet at a point of common tangency. The improved tube provides especially good results in systems, such as submerged-tube, refrigerated coolers, wherein the film resistance of the intube fluid would represent a substantial portion of the total thermal resistance if the improved internal surface were not provided. A method of designing a tube for a particular coefficient of internal heat transfer is also disclosed. |
