【作者】 黄鹏；

【导师】 赵建会；

【作者基本信息】 西安科技大学 ， 供热、供燃气、通风及空调工程， 2011， 硕士

【摘要】 随着现代工业的迅速发展,能源供应日益紧张,能源价格也在不断攀升。节能成为当务之急,世界各国都在寻找新能源和节能新途径。强化传热技术,由于能使各种换热设备的效率提高、重量和体积减小,一直受到科技界和工业界的重视。高效强化传热管的研究一直是传热领域最活跃和最有生命力的重要研究课题。螺旋槽管是其中的一个重要分支,螺旋槽管结构简单,成本低廉,用途广泛,结垢少且易清洗,其强化效果明显,因而倍受人们青睐。本文分析了螺旋槽管的强化传热机理,研究了三种槽截面分别为三角形、矩形和半圆形的螺旋槽换热管内的湍流流动和换热过程。利用Gambit软件建立三维模型并划分网格,运行Fluent软件进行了流动和换热的数值模拟,得出了管内温度场、压力场和速度场的分布。将三种螺旋槽管与光滑管的换热能力和流动压降进行了比较。在雷诺数在3981～35828范围内,三角形槽螺旋槽管的换热能力比光滑管提高了24%～50%,矩形槽螺旋槽管的换热能力提高了34%～61%,半圆形槽螺旋槽管的换热能力提高了31%～54%。但是三角形槽螺旋槽管的阻力系数比光滑管增加了113%～307%,矩形槽螺旋槽管阻力系数增加了116%～342%,半圆形槽螺旋槽管阻力系数增加了97%～283%。三种螺旋槽管的换热能力都得到了提高,但是其流动阻力也增大了,说明螺旋槽管的强化换热是以增大阻力为代价。通过采用Webb综合性能评价PEC-1指标对比得出,矩形槽和半圆形槽螺旋槽管的综合换热性能优于三角形槽螺旋槽管。更多还原

【Abstract】 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.更多还原