换热管内转子强化换热的数值模拟

Numerical Simulation of the Tube Inserted with Rotors-assembled Device for Heat Transfer Enhancement

本文概述了转子组合式强化传热装置的强化传热和自清洁原理。分别通过建立光管及内置多个转子换热管的三维流动模型,对换热管内流场、温度场、压力场以及换热过程进行了模拟,得到了管内流体的流动特性和传热特性。对比模拟结果表明,内置转子换热管管内的三维流动比较复杂,转子与管壁之间缝隙内的流体有着明显的环绕流动,切向速度和径向速度也增大到一定范围,转子旋转半径内的流体整体呈螺旋流动。总的来说,内置转子的换热管内较光管有较强的湍流度,尤其是近壁区域,因此强化了管内的对流换热,传热系数显著提高,从而验证了转子具有强化传热和自清洁的双重功能。

Principle of the rotors - assembled device for heat transfer enhancement and automatic cleaning was first introduced in the paper. Flow field, temperature field, pressure field and process of heat exchange were regarded to evaluate flow and heat transfer characteristics of the tube by building up 3 - D flow models of a plain tube and the tube inserted with several rotors. The comparison of simulation results showed that the three - dimensional flow in the tube inserted with rotors was very complex, with clear circular flow between rotors and the tube wall, while the tangential velocity and radial velocity increased to some extent,and the fluid inside the rotating radius flowed in a spiral way. In all, the tube inserted with rotors achieved stronger turbulence intensity than the plain tube, especially in the near- wall region. Therefore convective heat transfer was enhanced with heat transfer coefficient increased, which proved heat transfer enhancement and automatic cleaning functions of rotors.