Numerical Simulation Of Heat Transfer Enhancement In Spiral Groove Tube

With the rapid development of modern industry, energy is in short apply and the price is rising day by day. Energy-saving becomes the urgent matter and people all over the world are looking for new energy sources and searching for new ways to save energy. Technologies of heat transfer enhancement, which can improve the efficiency of heat exchanger and reduce the weight and volume of heat exchange equipments, are always attracted by scientists and engineers. The research on high-effective special shape tube for enhanced heat transfer is the most active and important research subject in heat transfer field. Spiral groove tube is one of the most important one, because of its simple frame, cheap cost, wide application, low scaling and is easy to clean , high strengthen effect, lots of peoples show favor towards it.In this paper, the strengthening heat transfer mechanism in spiral groove tube was analyzed. Turbulent flow and heat transfer process in three kinds of spiral groove tube heat exchangers with the cross-section of triangle, rectangle and semicircle were discussed. The 3D models were built and meshed by the software of Gambit, the numerical simulation of flow and heat transfer in these tubes were carried out by applying the Fluent software, from which we got the distribution of temperature field, stress field and the velocity field.Compared the Heat transfer ability and pressure drop in three spiral groove tubes and smooth tube, during the Reynolds number range of 3981~35828, the heat exchange capacity in triangle spiral groove tube was improved by 24%~50% than that in smooth tube, and the heat exchange capacity in spiral groove tubes with the cross-section of rectangle and semicircle was respectively improved by 31%~54% and 34%~61%. However, the resistance coefficient in triangular spiral groove tube increased by 113%~307% than that of smooth tube, the resistance coefficient in rectangular spiral groove tube increased by 116%~342% than that of smooth tube, and 97%~283% increased in semicycle spiral groove tube than that of smooth tube in same Reynolds number. Though the heat transfer ability in three kinds of spiral groove tube have improved obviously, the resistance coefficient are also increased. So the heat transfer enchancement is at the cost of increasing the resistance. Through the comparison of the comprehensive performance evaluation PEC-1 index, it can be seen that the spiral groove tube with the cross-section of rectangular and semicircle is better than the triangular section spiral groove tube at comprehensive heat transfer performance.