截短过热器分隔屏治理再热汽欠温的数值模拟  

Numerical Simulation of a Remedy of an Excessively Low Reheated Steam Temperature by Cutting Short the Partition Platens of a Superheater

作　　者：严林博[1] 何伯述[1] 裴晓辉[1] 杨敏[1] 

机构地区：[1]北京交通大学机电学院,北京100044

出　　处：《热能动力工程》2011年第1期67-72,123-124,共6页Journal of Engineering for Thermal Energy and Power

基　　金：中央高校基本科研业务费专项资金资助项目(2009JBZ017-1)

摘　　要：某电厂一期(2×600 MW)1号煤粉锅炉实际运行中长期存在二次汽(再热汽)欠温、过热器减温水过量、水平烟道入口左右侧汽温偏差大的问题而对锅炉运行的安全性和经济性带来了不利影响,急需对此进行全面分析并治理改造。经初步理论分析及数值模拟研究,决定对过热器分隔屏受热面进行截短改造。为了掌握分隔屏截短改造前后炉膛出口(水平烟道入口)烟气流场的变化情况,特别是在水平烟道入口是否形成烟气走廊,针对分隔屏分别截短1、2及3m前后的炉内等温流场进行了数值模拟研究,特别关注水平烟道入口流场的变化情况。根据数值模拟计算和热力校核计算结果的综合分析与对比,对分隔屏进行了截短2 m改造。实际运行表明,各负荷下二次汽温达到了设计值、过热器减温水平均下降了30 t/h左右、左右侧汽温偏差明显减少、炉膛出口(水平烟道入口)没有形成烟气走廊,改造取得了满意的效果。该改造方式对国内存在有类似问题的锅炉具有重要的参考意义。During the actual operation of No.1 pulverized coal-fired boiler in the first phase of a power plant(2×600 MW),the following problems existed for a long time,namely,an excessively low secondary steam(reheated steam) temperature,an excessively large amount of superheater desuperheating water and an excessively large steam temperature deviation between the left and right side of the horizontal flue gas duct at the inlet.These problems brought about an adverse influence on the operation safety and cost-effectiveness of the boiler and made it urgently necessary to conduct a comprehensive analysis,remedy and modification.Through a preliminary theoretical analysis and numerical simulation study,it was decided to perform a short-cut reconstruction of the heating surface of the partition platens of the superheater.To know well the variations of the flue gas flow field at the outlet of the furnace(inlet of the horizontal flue gas duct) before and after the reconstruction by cutting short the partition platens,especially,whether a flue gas corridor has been formed or not at the inlet of the horizontal flue gas duct,the reconstruction by cutting short by 1,2 and 3 meters of the partition platens respectively was studied and a numerical simulation study was performed of the in-furnace isothermal flow field before and after the reconstruction with special attention paid to the variations of the flow field at the inlet of the horizontal flue gas duct.Based on a comprehensive analysis and contrast of the numerical simulation calculation and thermodynamic check calculation results,it was decided to perform a reconstruction to cut short 2 meters of the partition platens.The practical operation shows that at various loads,the secondary steam temperature can reach the design value,the desuperheating water fed into the superheater averagely drops by about 30 t/h,the steam temperature deviation between the left and right side conspicuously decreases and no flue gas corridor is formed at the outlet of the furnace(inlet of the horizon

关 键 词：煤粉锅炉 过热器 二次汽 分隔屏 数值计算 

分 类 号：TK223[动力工程及工程热物理—动力机械及工程]