600 MW四角切圆燃煤锅炉灵活性改造后燃烧优化的数值模拟及验证  

Numerical simulation and verification of combustion optimization of 600 MW tangentially coal-fired boiler after flexibility retrofit

作　　者：潘博 陈晓龙 宋大勇 王赫 张海涛 王俊博 刘海玮 PAN Bo;CHEN Xiaolong;SONG Dayong;WANG He;ZHANG Haitao;WANG Junbo;LIU Haiwei(China Energy Science and Technology Research Institute Company Limited,210023 Nanjing,China;State Key Laboratory of Low-carbon Smart Coal-fired Power Generation and Ultra-clean Emission,210023 Nanjing,China;State Power Investment Group Northeast Power Company Limited,110181 Shenyang,China;School of Metallurgy,Northeast University,110819 Shenyang,China)

机构地区：[1]国家能源集团科学技术研究院有限公司,南京210023 [2]低碳智能燃煤发电与超净排放全国重点实验室,南京210023 [3]国家电力投资集团东北电力有限公司,沈阳110181 [4]东北大学冶金学院,沈阳110819

出　　处：《煤炭转化》2025年第1期124-133,共10页Coal Conversion

基　　金：国家能源集团科学技术研究院有限公司沈阳分公司科技创新项目(SY2023Y01)。

摘　　要：某600 MW四角切圆燃煤锅炉在完成灵活性改造后,于高负荷运行时出现炉膛出口烟气温度偏差大以及NO_(x)排放浓度控制难等问题。为此,运用流体计算仿真软件构建炉内燃烧、流动和传热全耦合的三维模型进行数值模拟计算,旨在确定锅炉的最佳运行参数。其中,采用Standard k-ɛ模型描述流体流动,运用双步竞争模型模拟煤中挥发分的析出过程,借助动力/扩散控制模型阐释焦炭燃烧反应,通过拉格朗日随机轨道模型考量煤粉颗粒与烟气的两相流过程,利用P1辐射模型计算炉内辐射传热,采用有限速率/涡耗散模型模拟气相燃烧,并通过后处理方式计算烟气中NO_(x)的质量浓度。重点分析了在100%锅炉最大连续蒸发量(BMCR)工况下,过量空气系数α、一次风率β和二次风角度θ等参数对炉膛切圆燃烧和出口处NO_(x)排放的影响。数值模拟结果表明:在锅炉实现良好切圆燃烧和低NO_(x)排放的条件下,最优运行参数为α=1.1,β=30%和θ=0°。通过锅炉燃烧调整试验对模拟结果的准确性予以了验证,试验结果表明:在最优运行参数下,锅炉省煤器出口的NO_(x)质量浓度降低了9.96%,排烟温度降低了2.66%,烟气温度偏差降低了2.26%,锅炉效率提高了0.28%。After completing the flexibility retrofit of a 600 MW tangentially coal-fired boiler,several issues arose during high load operation,including large flue gas temperature deviations at the furnace outlet and difficulties in controlling NO_(x) emissions.To address these challenges and determine the optimal operating parameters of the boiler,a three-dimensional model of combustion,flow and heat transfer in the furnace was constructe dusing the computational fluid dynamics software.The established model employed the standard k-ɛmodel to describe fluid flow,the two-step competition model to simulate the release of volatile matter in coal,the dynamic/diffusion control model to explain the coke combustion reaction,the Lagrangian stochastic trajectory models to consider the two-phase flow process of pulverized coal particles and flue gas,the P1 radiation model to calculate the radiation heat transfer in the furnace,the finite rate/eddy dissipation model to simulate the gas phase combustion,and NO_(x) mass concentration in flue gas was calculated based on the simulated combustion field in a post-processing way.The effects of excess air coefficient α,primary air rate β and secondary air angle θ on furnace tangential combustion and NO_(x) emission at the outlet were analyzed in the condition of 100% BMCR.The numerical results show that the optimal operating parameters areα=1.1,β=30% and θ=0° to achieve both good tangential combustion and low NO_(x) emission.The simulation results were validated by a boiler combustion adjustment test.The test results demonstrate that under the optimal operation parameters,NO_(x) mass concentration at the economizer outlet of the boiler is reduced by 9.96%,exhaust gas temperature is reduced by 2.66%,flue gas temperature deviation is reduced by 2.26%,and the boiler efficiency is improved by 0.28%.

关 键 词：600MW燃煤锅炉 燃烧优化 温度场 切圆燃烧 数值模拟 

分 类 号：TM621.2[电气工程—电力系统及自动化]