传热管内强化齿型扭带自动清洗技术研究

Auto-cleaning Technology of Twisted Strip with Teeth in Heat Transfer Tubes

低流速冷却设备的水垢严重影响运行效率,自动清洗光滑扭带在低流速下的自转力矩太弱不能应用。为此,研制一种能够显著增大自转力矩的强化齿扭带,对强化齿扭带的结构进行了理论分析和设计,并且进行了多种结构参数的扭矩优化试验和传热试验、流体阻力测试。试验结果表明,12T55t6-65型强化齿扭带较好,与光滑扭带相比:自转力矩增大277%,传热系数提高22%,流体阻力在工程许可范围。因此,这种强化齿扭带可以在低流速的列管式传热设备中广泛应用。

The operation efficiency is affected seriously by water fouling of heat exchangers of low flowing velocity. The technique of twisted strips to autoclean fouling cannot be used because of the low flowing velocity and little rotational moment. So, the twisted strip with teeth is developed to enhance the moment notably. The strip structure is analyzed theoretically and designed. Several experiments such as of rotational moment, of heat transfer, and of flowing resistance were conducted to optimize the structure parameters. The results show that the twisted strip No. 12T55 t665 is better. The moment and heat transfer coefficient increases by 277% and 22% respectively compared with that of the smooth twisted strip without any teeth. The flowing resistance is in the range of engineering permission. Therefore, the new kind of twisted strip with teeth can be used widely in shelltube heat exchangers of low flowing velocity.