660MW燃煤锅炉屏式过热器壁温特性数值模拟研究  

Numerical simulation research on heat transfer characteristics of platen superheater of 660MW coal-fired boiler

作　　者：王涛[1] 周托 吕俊复[2] 吴玉新[2] 张天宇 马有福[1] WANG Tao;ZHOU Tuo;L Junfu;WU Yuxin;ZHANG Tianyu;MA Youfu(School of Energy and Power Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Department of Energy and Power Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]清华大学能源与动力工程系,北京100084

出　　处：《煤炭学报》2022年第11期3860-3869,共10页Journal of China Coal Society

基　　金：国家重点研发计划资助项目(2019YFE0125900)。

摘　　要：在“双碳”目标的背景下,燃煤火电机组向更高参数及深度调峰的方向发展,这对于燃煤锅炉的运行提出了更高的要求,防止锅炉受热面热偏差而导致的管壁超温是其中的关键问题之一。因此,精确预测燃煤锅炉受热面的热偏差和壁温对于机组安全、稳定运行意义重大。锅炉受热面的传热及壁温特性主要受到烟气侧和工质侧的共同作用,但在通过数值模拟方法预测热偏差问题时,常将模拟过程和边界条件进行简化处理,较难精准地分析受热面的传热及壁温分布特性。针对以上问题,利用Fluent对660 MW前后墙对冲燃煤锅炉进行了数值模拟,建立了屏式过热器管内、外的耦合传热模型,提出了按管内工质流动方向的顺序计算方法,并基于UDF实现了烟气侧与工质侧的传热耦合计算。研究了外二次风不同旋流角度对屏式过热器传热的影响,获得了同时考虑烟气侧和工质侧的屏式过热器传热及壁温特性。模拟结果表明,屏式过热器各管屏第22号管子出口壁面温度与实测值的相对误差在4%以内;外二次风的旋流角度由15°增加至60°,煤粉气流刚性减弱,燃烧不剧烈,煤粉着火延迟,炉膛火焰面升高,且屏式过热器的温度分布由“两端高、中间低”向“两端低、中间高”变化;当旋流角度为45°和60°时,屏式过热器的最大壁温分别为945 K和965 K,超过受热面材料的最大允许温度,而当旋流角度为15°和30°时,屏式过热器的最大壁温小于受热面材料的最大允许温度,故最佳旋流角度应选取15°~30°。Due to the “dual carbon” target, coal-fired thermal power units are developing to higher parameters and deeper peaking, which causes higher requirements for coal-fired boilers. Preventing the over-temperature of the tube wall caused by the thermal deviation of the heating surface is one of the key issues. Therefore, accurate prediction of thermal deviation and wall temperature of the heating surface of coal-fired boilers is of great significance for safe and stable unit operation. The heat transfer and wall temperature characteristics of the heating surface of the boiler are affected by the combined action of the flue gas side and the steam side. When predicting the thermal deviation problem through numerical simulation, the simulation process and boundary conditions are often simplified, and it is difficult to accurately analyze the heat transfer and wall temperature distribution characteristics of the heating surface. For the above problems, numerical simulation of the 660 MW front and rear wall-hedged coal-fired boilers is carried out by Fluent, and the coupled heat transfer model inside and outside the tube of the platen superheater is established. The sequential calculation method according to the flow direction of the steam in the tube is proposed, and the coupled calculation of heat transfer between the flue gas side and the steam side is realized based on UDF. Meanwhile, the influence of different swirl angles of the external secondary air on the heat transfer of the platen superheater is studied, which requires the heat transfer and wall temperature characteristics of the platen superheater considering both the flue gas side and the steam side. From the results, it can be concluded that the relative error of the outlet wall temperature at the No.22 tube of the platen superheater is within 4% of the test values. The swirl angle of the external secondary air increases from 15° to 60°,the rigidity of the pulverized coal flow is weakened, the combustion is not violent, the ignition of the pulverized co

关 键 词：燃煤锅炉 屏式过热器 壁温 数值模拟 耦合计算 

分 类 号：TK16[动力工程及工程热物理—热能工程] TM621.2[电气工程—电力系统及自动化]