电厂孔板下游流动加速腐蚀模拟研究

Simulation research on flow-accelerated corrosion in downstream of orifice plate for power plants

使用计算流体软件对电厂孔板下游流场进行模拟分析,研究不同流速和不同孔径比对孔板下游流场分布、传质系数的影响规律,并基于所建立的流动加速腐蚀(FAC)过程模型,确定孔板下游的腐蚀行为与流速、孔径比之间的相关性。结果表明:孔径比一定时,孔板下游传质系数和流动加速腐蚀速率随着流速增大整体呈现增大趋势,并且腐蚀峰值出现位置向孔板下游偏移;流体流速一定时,孔径比越小,传质系数和流动加速腐蚀速率越大,腐蚀高发区向孔板方向移动。该模拟结果与实验结果较吻合。

The computational fluid software was used to simulate the flow field at downstream of the orifice plate in power plants, and the influence of velocity and aperture ratio on flow field distribution and mass transfer coefficient at downstream of the orifice plate was studied. Based on the established flow-accelerated corrosion (FAC) model, the correlation between the corrosion behavior at downstream o f the orifice plate and the velocity and aperture ratio was determined. The results show that, when the aperture ratio is constant, the mass transfer coefficient and the corrosion rate of the orifice plate increase with the velocity, and the position of the maximum corrosion rate shifts to downstream of the orifice plate. When the velocity of the fluid is constant, the smaller the pore diameter ratio is, the greater the mass transfer coefficient and the corrosion rate are, and the high-incidence area of corrosion moves toward the orifice plate. The results obtained by this model agree w ell with the experimental results.