高效传热斜齿扭带的自动清洗动力学设计理论

Dynamics Design Theory of the Self-Cleaning Twisted Strip with Oblique Teeth to Enhance Heat Transfer

塑料斜齿扭带是自动清洗扭带技术研究30多年来取得的最重要进展,突破了低流速自动清洗难关,极大地拓宽了应用范围,突破传热强化弱的难关成为高效传热强化的一种新元件。本文专题研究了这一新技术的动力学设计理论及其工程应用问题。研究中将复杂的斜齿扭带动力矩近似分解为虚拟的光滑扭带动力矩及其螺旋线液流对斜齿的冲推力矩之和,建立了动力矩理论计算式。通过对该计算式的工程应用研究,得到了有关优化设计方面诸多的重要结论。在该式指导下设计的斜齿扭带优化试验结果表明,斜齿扭带的自转动力矩和传热系数均比光滑扭带成倍提高,设备总阻力也在工程许可范围内。

The self-cleaning technology of twisted strip with oblique teeth is the most importan timprovement during the past 30 years. It breaks through the applicationlimit of low flowing velocity. With this insert in tubes, heat transfer can be enhanced effectively. This paper researches the dynamics design theory of this technolog y and its application in engineering. The driving force moment of twisted strip with oblique teeth and inlet contrarotation bearing are composed of twoparts: the driving force moment of virtual smooth twisted strip and the force moment of spirally flowing fluid on the oblique teeth attached on the strip. The calculati on formula is built. Through researching the formula application in engineering, many important conclusions are drawn about optimization design. With the twisted strip with teeth designed under the guide of it, the experiments showthat the driving force moment and heat transfer coefficient are increased by times over the smooth strip. The overall flowing resistance of heat exchanger is inthe permi ssion range of industrial application.