螺旋槽管换热过程的三维速度场与温度场耦合数值模拟

根据螺旋槽管换热器结构特点及传热特性,建立了以水为工质的换热器流动与传热的三维几何模型。运用有限元分析软件ANSYS模拟出换热器在换热过程中速度场与温度场的状况,分别得到了螺旋槽管内壁与外壁的对流换热系数。结果表明:槽深越大,随着Re增大,换热性能越好;当Re较小时,螺距越大,换热效果降低。其与该类光管换热器相比,得出螺旋槽管的换热系数是光管的2.5倍左右,强化了传热,为此产品的进一步理论研究和推广应用提供了依据。

Numerical Simulation of a Three-dimensional Velocity Field Coupled With a Temperature Field for the Heat Exchange Process in a Spirally Grooved Tube

On the basis of structural features and heat transfer characteristics of a spiral-grooved tube heat exchanger,a three-dimensional geometric model was established for the flow and heat transfer in a heat exchanger with water serving as its working medium.By employing a finite-element analysis software ANSYS,simulated were the conditions of the velocity and temperature fields in the heat exchanger during its heat exchange process and obtained were the convective heat exchange coefficients for inner and outer walls of the spiral-grooved tubes respectively.The simulation results show that the deeper the groove,with an increase in Reynolds number,the better the heat-exchange performance.When the Reynolds number is relatively small,the greater the fin pitch,the poorer the heat exchange effectiveness.It has been found that the heat exchange coefficient of the spiral-grooved tubes is approximately 2.5 times that of the bare tubes when compared with the bare tube heat exchangers of the same kind,thus intensifying the heat transfer and providing a basis for the further theoretical research and widespread application of such products.