螺旋内肋管换热及流体流动数值研究

Numerical Simulation on Heat Transfer and Fluid Folw in Spirally Inner Finned Tube

利用CFD技术,针对螺旋内肋管的不同结构参数,对不同螺距、螺旋角和肋高等27组结构进行数值研究,详细分析了各个结构参数对流体流动及换热的影响.结果表明,适当减小螺距可有效提高管侧对流换热能力,同时伴随着阻力降增大,换热性能对雷诺数的增长趋势更为明显,综合性能趋势向好.随着肋高的增大,在高雷诺数区域强化管的换热性能随肋高的增加变化得更为明显,且摩擦系数增加的比例与肋高增加的比例大致相当.拟合了螺旋内肋管换热及阻力性能公式,同时对强化管综合性能做出评价.

The CFD method was applied to investigate the preformance of heat transfer and fluid flow in spirally inner finned tubes with different baffle spacing, spiral angle, and fin height for 27 different groups combination. The numerical simulation results show that decreasing baffle spacing can improve the performance of heat transfer on shell side. However, the pressure drop of fluid flow increases with decreasing of baffle spacing. But the performance of heat transfer increases greater than the pressure drop dose with Reynolds number in- creasing, and the enhanced tube has better performance compared with the smooth tube. With the fin height increase, the comprehensive performance of enhanced tube increase more obviously at high Reynolds number region. The formulae of heat transfer and fluid flow are fitted and the comprehensive performance of the enhanced tube is evaluated.