双U型火焰液态排渣锅炉纯燃高碱煤热力计算及数值模拟研究  

Thermal calculation and numerical simulation on double-U flame slag-tap boiler that fully burning high-alkali coal

作　　者：杨家辉 汪瑾 马翔 邓磊[1] 笪耀东 车得福[1] YANG Jiahui;WANG Jin;MA Xiang;DENG Lei;DA Yaodong;CHE Defu(State Key Laboratory of Multiphase Flow in Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;Xi’an Thermal Research Institute Co.,Ltd.,Xi’an 710054,China;China Special Equipment Inspection and Research Institute,Beijing 100029,China)

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,陕西西安710049 [2]西安热工研究院有限公司,陕西西安710054 [3]中国特种设备检测研究院,北京100029

出　　处：《热力发电》2024年第1期38-45,共8页Thermal Power Generation

基　　金：国家重点研发计划项目(2018YFB0604103)。

摘　　要：对液态排渣锅炉的深入研究将会推动纯燃高碱煤技术的推广。以一台超临界350 MW机组直流双U型火焰液态排渣锅炉为研究对象,以燃烧室、捕渣管束和冷却室为单元,从热平衡的角度出发展开热力计算,并借助数值模拟手段,研究了炉膛内设计工况下的流场、温度场和组分场及其在变负荷时的变化情况。热力计算和数值模拟表明,几处烟气温度结果偏差都低于40.0℃。燃烧室出口烟气温度偏差仅为1.2℃,冷却室出口烟气温度偏差为15.6℃。经过验证和比较,所采用的热力计算方法可以应用于双U型火焰液态排渣锅炉纯燃高碱煤热力计算。数值模拟结果显示,炉内空气动力场良好,旋流形成的回流区可以增加煤粉颗粒在燃烧室的运动路径,促进煤粉的燃尽。烟气在流经捕渣管时,温度大大降低,同时流场也受到了一定的扰动,可以有效捕捉灰渣。在变负荷工况下,炉内的速度场按负荷降低成比例下降,回流区的大小基本不变。炉内的温度水平降低,当给煤量由100%降至75%时,燃烧室出口烟温降低了约75℃,而冷却室出口烟温降低了约200℃。本研究可为双U型火焰液态排渣锅炉纯燃高碱煤提供参考。Further research on slag-tap boiler can promote the application of fully burning high-alkali coal technology.In this study,a supercritical 350 MW once-through double-U flame slag-tap boiler is taken as the research object and the combustion chamber,slag collection tube bundle and cooling chamber are taken as the calculation units,the thermal calculation is performed from the perspective of heat balance.The flow field,temperature field and component field in the boiler under design condition and at variable loads are studied.The deviations of several flue gas temperature results obtained by thermal calculation and numerical simulation are within 40 K.At the outlet of the combustion chamber,the deviation is only 1.2 K.The temperature deviation of flue gas at the outlet of cooling chamber is 15.6 K.After verification and comparison,it is concluded that the thermal calculation method adopted can be applied to the thermal calculation on double-U flame slag-tap boiler that fully burning high-alkali coal.The flow field is well organized.The recirculation zones formed by swirling flow can increase the movement path of pulverized coal particles in the combustion chamber and promote the burning.When the flue gas flows through the slag collection tube bundle,the temperature greatly reduces.The flow field is also disturbed,which can effectively capture the ash.At variable loads,the velocity field in the boiler decreases proportionally according to the reduction ratio of the amount of coal.However,the size of the recirculation zones is basically unchanged.The temperature level in the boiler reduces,when the amount of coal reduces from 100% to 75%,the flue gas temperature at the outlet of the combustion chamber reduces by about 75 K,and the flue gas temperature at the outlet of the cooling chamber reduces by about 200 K.This study can provide reference for fully burning high-alkali coal in double-U flame slag-tap boiler.

关 键 词：高碱煤 液态排渣锅炉 纯燃 热力计算 数值模拟 

分 类 号：TM621.2[电气工程—电力系统及自动化]