鳍片管省煤器结构优化的三维数值模拟

利用FLUENT6.2软件对气流横向冲刷鳍片管管束的流动和换热特性进行模拟,分析了管间距对换热和流动的影响,拟合出传热特性关联式,根据尾部烟道的速度分布特点采用变节距的排管方式对省煤器进行优化;并针对某200 MW锅炉省煤器采用多孔介质和热交换器模型进行模拟计算,研究表明:采用变节距排管方式的省煤器换热效果优于原来的省煤器,两者气体流动压降差别不很大。对电厂省煤器结构优化提高换热效率具有一定指导意义。

Three-dimension numerical simulation of structure optimization of rectangular fin tube economizer

The FLUENT6.2 software was employed for numerical simulating heat transfer and flow characteristic of the gas when it flow through rectangular tube bundles in transverse direction,the array separation of tubes effected to heat transfer and flow was analyzed,the correlation equation of heat transfer characteristic was derived,and based on the velocity distributing the rational tube arrangement was adopt to optimize economizer.Taking a certain power plant's 200 MW boiler economizer as an example,the porous medium model and heat exchanger model were employed for simulating.The study result indicates that the heat-exchange performance of the economizer taking variable-pitch tube arrangement is excelled than the primary one,the discrepancy of gas pressure drop of them is narrow.The essay has direct significance for the structure optimizing and increasing heat exchange efficiency of power plant economizer.