摘要
为掌握液态排渣锅炉全烧和大比例掺烧高碱煤的关键参数和运行经验,基于某电厂300 MW等级液态排渣锅炉进行了长期工程试验,对可能存在的燃烧组织、NOx控制、排渣和沾污等问题进行分析,针对性的对燃烧系统、热物改性系统和排渣系统进行了改造.并进行了长期的运行数据记录和关键参数记录,在全烧和高比例掺烧高碱煤30万t后,锅炉各项运行参数正常.工程试验证明:该电厂300 MW等级液态排渣锅炉经升级优化后对高碱煤的的适应能力极强,在燃煤组分w(A12O3)＜25％、w(Fe2O3)＜15％、12％＜w(CaO)＜30％、硅铝比大于1.7、碱酸比大于0.5时均可以保证机组正常运行且没有明显沾污;燃用高碱煤后可有效降低第一级受热面入口烟气温度至设计值以下,避免锅炉第一级受热面结渣情况,NOx生成量也较燃用原设计煤种下降超30％.
Abstract
In order to understand the key parameters and operating experience on fully burning and high proportion blend burning high-alkali coal in boiler with slag-tap furnace,long-term engineering tests were conducted based on a 300 MW boiler with slag-tap furnace in a power plant.An analysis was conducted on the possible combustion organization,nitrogen oxide control,slag flow,and ash deposition issues.Modifications were made to the combustion system,thermal modification system,and slag flow system.So long-term operational data and key parameter records were conducted,after fully burning and high proportion blending burning of 300 000 tons of high-alkali coal,all operating parameters of the boiler were normal.Based on recent operations and comprehensive tests,the optimized boiler with slag-tap furnace in a specific power plant demonstrates strong adaptability to high-alkali coal.Within the control range of coal ash components with w(Al2O3)＜25％,w(Fe2O3)＜15％,12％＜w(CaO)＜30％,silica-alumina ratio＞1.7,acid/alkali ratio＞0.5,the normal operation of the boiler can be ensured without obvious ash deposition.Burning high-alkali coal can effectively reduce the inlet flue gas temperature of the first-level heating surface to below the design value,effectively avoiding the occurrence of slagging on the first-level heating surface of the boiler,and the generation of nitrogen oxides is also reduced by more than 30％compared with using the original design coal.
基金项目
国家重点研发计划项目(2018YFB0604105)
国家科技期刊平台
NSTL
维普
万方数据