内置转子换热管强化传热数值模拟

Numerical simulation on enhanced heat transfer of heat-exchange tube with assembled rotors

为分析内置转子换热管的传热效果,建立光管和内置转子换热管的三维模型,对换热管内流场、温度场、压力场以及传热过程进行模拟,得到管内流体的阻力特性和传热特性.模拟结果表明:内置转子换热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明显的环绕流动,切向速度和径向速度也增大到一定范围;相同雷诺数条件下,内置转子换热管压降比光管增大2.09～2.66倍,管内流体进出口温差比光管增加0.67～0.76℃.内置转子换热管较光管有较强的湍动程度,尤其是近壁区域,因此强化管内的对流传热,传热系数显著提高,从而验证转子具有强化传热的功能.

To analyze the heat transfer effect of heat-exchange tube with assembled rotors,the 3D models of a plain tube and a heat-exchange tube with assembled rotors are established,the flow field,temperature field,pressure field and process of heat transfer in the tubes are simulated,and the flow and heat transfer characteristics of the tubes are obtained.The simulation results indicate that the circular flow between rotors and tube wall is obvious,the tangential velocity and radial velocity increase to some extent,so the 3D flow in the heat-exchnge tube with assembled rotors is very complex;under the same Reynolds numbers,the pressure drop and temperature difference between inlet and outlet of the heat-exchange tube with assembled rotors increase to 2.09~2.66 times and 0.67~0.76 ℃ than those of plain tube.The heat-exchange tube with assembled rotors achieves stronger turbulence intensity than the plain tube,especially in the near-wall region.Therefore,the convective heat transfer is enhanced and the heat transfer coefficient is increased,and the rotors are proved to be with enhanced heat transfer function.