Numerical Simulation And Optimization For The Heat Transfer Performance Of Two Typical Types Of Heat Exchange Tubes

Heat exchangers are widely used in refrigeration, chemical industry, petroleum, power, etc. In the industry, it is the general equipment, and it has a specially important position, especially in the chemical processing and oil refining. At present, tube and shell heat exchanger is the most widely used and is one of the most important. So a study for the heat transfer enhancement of tube and shell heat exchanger is necessary. This paper respectively researches enhanced heat transfer of tube heat exchanger and shell side heat exchanger.In the heat transfer enhancement of tube side, taking sinusoidal corrugated tube as the research object, we adopt simplified two-dimensional model to study the effects of volatility, pitch of waves and Reynolds number to strengthen sine corrugated tube heat exchanger. By comparing eight kinds of sinusoidal corru-gated pipe, results show that the band of corrugated pipe has significant effects on tube heat exchange enhanced, and pitch of waves has no influence. We use the cooperative principle to analyze its reasons. Furthermore, we explore the impacts of the ratio ? of amplitude and pitch of waves on strengthening sine cor-rugated tube heat exchanger. Heat energy is higher in range from 0.25 to 0.3. In the meanwhile, the comprehensive heat transfer performance (PEC) of bellows in different Reynolds number is computed. Results show that PEC of bellows is small in lesser Reynolds number even less than 1, and PEC of bellows can reach 1.3 in larger Reynolds number. The optimal structure an optimal range of Reynolds number for the heat transfer enhancement of sine corrugated pipe are obtained.Taking traditional shell-tube heat exchanger with segmental baffles as the research object, we study the heat transfer enhancement of shell side. Opening of baffle plate in proper place is an effective way to improve comprehensive heat transfer performance of heat exchange. By the comparative study of seven open-ing plans, we analyze the characteristics of the heat transfer and pressure drop. Studies show that the opening area of the baffle plate and the hole location are two factors affecting heat transfer. Finally, by the comprehensive heat transfer performance evaluation factor EEC, it can be found that EEC will increase with the scope of opening area; In the same opening area, when baffle opening is in the region of bigger pressure, EEC is larger. Under different Reynolds number, the optimization trends are different. In the larger opening area, when Reynolds number is low, EEC is larger; In the smaller opening area, when Reynolds number is large, EEC is large. But it has no effect on the whole optimization selection.