燃气-蒸汽联合循环余热锅炉入口烟道结构优化数值模拟研究

Numerical Simulation on Structure Optimizing of Inlet Ducts in Gas-steam Combined Cycle Heat Recovery Steam Generators

应用通用软件FLUENT,对余热锅炉入口段的流场进行两维和三维数值模拟。采用标准k-ε两方程模型进行建模,方程的离散采用二阶迎风差分格式,并使用SIMPLE算法求解方程。将余热锅炉受热面管束处理为具有分布阻力和分布质量汇的多孔介质模型。得出了不同入口段结构对应的出口速度分布;根据出口速度的均匀性,确定了入口段最佳结构;并对两维和三维模型模拟结果的差异进行了分析。

The 2-D and 3-D numerical simulation of flowing field in inlet ducts in gas-steam combined cycle heat recovery steam generators are made applying CFD soft ware FLUENT in this paper. The theoretical models are established based on κ-ε model. The method of discretization of models is Second up wind scheme. The computing method is SIMPLE. The heating surface in HRSG is made into porous medium. The velocity distributions at the outlet of inlet duct with different structure are obtained. The optimized inlet duct is proposed on the basis of the velocity distributions at the outlet. The comparison between the 2-D and 3-D numerical simulation results is made.