The Research And The Heat Transfer Performance Of Spiral Groove Tube Flow

As a kind of high efficient heat transfer special-shaped tube, spiral grooved tube has been widely used in the various fields of national economy, according to the type of tube of strengthening heat transfer research has also been a hot spot nowadays. The structural parameters of spiral grooved tube including bore diameter D, pitch P, groove depth e, helix Angle beta and Numbers N, all of these structural parameters af fect the spiral groove tube comprehensive heat transfer ability of the spiral groove tub e.Research of enhancing the heat transfer is also research of the influence of these par ameters on heat transfer and flow in pipe. By using Fluent software and strong analyti cal skills of computer, numerical simulation of the spiral fluted tube reinforced heat ex change and pipe flow, compared with the ordinary light tube heat exchange ability and pipe flow, some useful conclusions were made.Firstly, this article described strengthen heat transfer briefly, and introduced the p resent situation and the development tendency of domestic and foreign research, also analysised the spiral fluted tube to strengthen heat transfer mechanism. Spiral grooved tube strengthening heat transfer can be divided into no phase transformation strengthe ning in heat and phase transformation strengthening heat transfer, mainly introduced t he mechanisms of two kinds of strengthening heat transfer.For no phase transformatio n strengthening heat transfer research, this paper analyzed the convective heat transfer boundary layer thermal resistance, the lower boundary layer thermal resistance and th ought that thinned boundary layer thickness is the main mechanism of spiral groove tu be strengthening heat transfer.Secondly, roll forming of the second to ordinary light pipe and spiral groove tube as the research object, the medium of water on the surface of the two type of pip e heat exchanger convective thermal dissipation theory analysis, the theoretical model is established. Using Fluent software for two type of pipe heat exchanger in3D nume rical simulation, and the calculated results with the theoretical value were analyzed. U sing the Fluent software to simulate software for spiral groove tubes and light tube of t emperature field, velocity field, pressure field and so on, calculate the average convect ive heat transfer coefficient of pipe of two. Focus on analysis of the spiral groove tube pitch p, groove depth e, the influence of working medium for enhancing heat transfer, the research shows that the Re number in10000-50000, within the scope of the spira1groove tube heat exchange capacity is2.1-3.6times of the light pipe, different stru ctural parameters of the combined influence of spiral grooved tube heat exchange and pipe flow, pitch p=10mm, groove width b=3mm, groove depth e=1.25mm of spi ral grooved tube in tube Reynolds number Re in10000->50000comprehensive perfor mance between the best eta, eta and largest comprehensive performance of1.27.Finally, on the basis of predecessors’ research, the paper analysised and summed up a set of evaluation index of spiral grooved tube heat exchange performance, on the basis of the first condition from the Webb-Bergels evaluation,on the study of spiral g roove tube heat transfer performance assessment, and put forward the reasonable opti mization design scheme, to provide theoretical basis for the production, implement the predictability of heat exchange.