Manufacture By Rolling-plowing/Extrusion Process And Heat Transfer Performance Of Outside3D Integral Fins On Stainless Steel Tubes

With the increasing of the energy resources consumption, the energy resources in theworld is used increasingly nervously, Energy saving ana emission reduction become moreand more important in the industrial applications.The outside three-dimension integral finswhich are as the third generation heat transfer enhancement technology have excellent heattransfer performance,so it can be widely used in industrial practice. The research aboutheat transfer enhancement performance and methods of fabrication manufacture ofthree-dimension integral fins become more and more important. While the manufacture ofthree-dimension integral fins have difficulty. Especially the stainless steel tube which workin worse condition is as the base tube, the manufacture is more difficult. In this condition,base on rolling-plowing/extrusion process methods, plowing/extrusion tool is developed,Three-dimension integral fins on the stainless steel tube is successfully manufactured. Themainly research works are summarized as follows:(1)Experiment study of rolling process on the stainless steel tube2D spiral grooves were gained on the stainless steel tube by rolling process. Thereasonable rolling speed and feed rate were choosed, and the effect of rolling depth to thespiral grooves are researched by rolling experiment. Reasonable rolling parameters wereobtained for fabricating singed V-shape spiral grooves.(2)Development of a new plowing/extrusion toolBased on the exiting plowing/extrusion tool and cutting theory, a newplowing/extrusion tool was developed. Geometric and mathematic model were establishedand the relationship among the geometric parameters of plowing/extrusion tool wereensured. Based on the new plowing/extrusion tool, plowing/extrusion critical feed rate andmaximum plowing/extrusion depth are ensured by micro-units tool.(3)Experiment study of plowing/extrusion process on the stainless steel tube andoptimization of the paremetersThe Outside3D integral fins on the stainless steel tubes were manufactured by plowing/extrusion. Finned appearance by different manufactured technology paremeterswas analyzed which were based on the experimental results; the effect regularity ofplowing/extrusion tool parameters and process parameters to the finned height,thicknessand pitch were analyzed by single factor experiment; The effect regularity ofplowing/extrusion feed rate and depth and plowing/extrusion tool nose arc radius andcutting edge angle on finned height were analyzed by multi-factor experiment; the cuttingforce experiments on plowing/extrusion process were carried out, cutting force wasobtained, the experiment results of cutting force results showed that the cutting force onplowing/extrusion process changed in bigger range than common cutting, and feed force isnegative, those have better guide meaning to the tool design.(4)Condensation heat transfer of outside3D integral fins on the stainless steel tubesThe smooth tube and three kinds of outside3D integral fins on the stainless steel tubeswere tested at the saturated vapor temperature of39℃for R22, the overall heat transfercoefficient and condensation heat transfer were compared. The experiment results wereshowed that heat transfer performance of three kinds of outside3D integral fins on thestainless steel tubes is over two times higher than the smooth tube, so the outside3Dintegral fins on the stainless steel tubes can replace the smooth tube as condensation heattransfer tube.