凝汽器循环水二次滤网整流特性的数值模拟..doc

凝汽器循环水二次滤网整流特性的数值模拟 李勇1,李立言1,曹丽华1,程朝卿2 （Numerical Study on Rectification Characteristics of Condenser Circulating Water Secondary Filter LI Yong1,LI Li-Yan1,CAO Li-hua1,CHENG Chao-Qing2 (1. Institute for Energy and Power Engineering, Northeast Dianli University, Jilin 132012, Jilin Province, China;2. Zhong Dian Lv Bo Company of Beijing,100081, Beijing, China)Abstract: The circulating water secondary filter of condenser affected not only the purity of the circulating water, but also the uniformity of inlet chamber’s flow field. By using Realizable k-ε turbulence model and Finite volume method, an numerical simulate and comparison were made between the flow of inlet chamber of the condenser influenced by well-shape secondary filter and punching-shape secondary filter with FLUENT6.3 numerical simulation software. The research shows: the water resistance of the well-shape secondary filter is smaller than punching-shape secondary filter in the same flow rate limit. as well as installing well-shape secondary filter is beneficial to improve the uniformity of flow fields. This paper has directive significance for choosing circulating water secondary filter, reducing the consumption of the circulating water pump power and improving the vacuum of condenser. KEY WORDS: circulating water secondary filter；numerical simulated；flow rate；uniformity；water resistance 摘要：凝汽器循环水二次滤网不仅对凝汽器循环水的清洁度产生较大的影响，同时也影响到凝汽器循环水入口流场的均匀性。文中利用FLUENT6.3数值模拟软件，采用Realizable k-ε双方程紊流模型和有限体积算法，分别对加装井字网孔型二次滤网、冲孔型二次滤网前后凝汽器入口水室进口处流场分布情况进行了数值分析和比较。结果表明：与常规的冲孔型二次滤网相比，在通流倍率相同的条件下，井字型二次滤网阻力较小。而且，井字型二次滤网后循环水流场的均匀性也要好于常规的冲孔型二次滤网。本文研究对于选择凝汽器循环水二次滤网型式，减少循环水泵功耗，促进凝汽器真空的提高，具有一定的指导意义。 关键词：循环水二次滤网；数值分析；通流倍率；均匀性；阻力 基金项目：吉林省科技发展计划项 1 引 言 为了防止凝汽器循环水中的杂质进入凝汽器，改善循环水的质量问题，各个火电厂普遍采用循环水二次滤网来去除杂质，以提高凝汽器的换热效率[1-3]。但加装二次滤网之后，必然会对循环水流场产生一定的阻力，从而增加循环水泵的功耗[4,5]。因此，对于优化二次滤网工作性能的研究已成为国内外学者主要的工作之一。文献[6]对堵箱旋转反冲洗型二次滤网通过加装O型环、延长冲洗时间、压差补偿等改进措施防止了二次滤网频繁漏水和维修工作量大的缺点，为核电厂重要厂用水系统的正常运行提供了保障。文献[7]分析通过对某堵箱排污型二次滤网的结构和工作原理的分析，通过实验总结出该二