300 MW机组锅炉改烧烟煤改造及防结焦措施  

Retrofitting of burning bituminous coal for a 300MW unit boiler and the anti-coking countermeasures

作　　者：郑国[1] 龙新峰[2] 

机构地区：[1]湛江电力有限公司,广东湛江524099 [2]华南理工大学化学与化工学院,广东广州510641

出　　处：《热力发电》2015年第11期118-123,共6页Thermal Power Generation

摘　　要：为适应煤炭市场形势和发展需要,对湛江电力有限公司(湛江电厂)4×300 MW机组配套的1 025t/h锅炉进行了改烧高挥发分烟煤和机炉协同增容升级改造。针对锅炉改烧烟煤后容易出现的炉膛结焦问题,通过数值模拟计算对炉膛结焦风险进行了评估,提出了制粉系统改造、更换燃烧器、增加锅炉受热面等锅炉整体改造方案,以及采用浓煤粉气流反切的水平浓淡燃烧器,增加内切圆直径,减小外切圆直径等防结焦措施。改造后,锅炉可以安全燃用干燥无灰基挥发分为40%以上的烟煤,锅炉结焦情况良好,锅炉最大连续出力为1 077t/h,锅炉效率提高到93.22%以上,锅炉汽温、汽压、蒸汽流量等指标均达到设计要求。但由于印尼煤和神混三煤的灰熔点较低,单一燃烧该煤种时炉内结焦严重,建议该煤种掺配比例不超过50%。In order to adapt to the changes in the coal market and satisfy the relative requirements,the1 025t/h boilers in 4×300 MW units of Zhanjiang Electric Power Company were retrofitted,the fuel was changed into bituminous coal with high volatile matters and the capacity of both the boiler and the turbine was enlarged.After the retrofitting,coking problem easily occurred in the boiler.Thus,the furnace coking risk was assessed by numerical simulation,and the boiler integral transformation scheme was proposed,which includes the pulverizing system retrofitting,changing the burners,increasing the heating surface area,applying horizontal bias burner,reducing the excircle diameter,and other anti-fouling measures.After this transformation,the boilers can safety burn bituminous coal with volatile content of above 40%（dry ash free basis）,and the fouling situation turned well,the boiler maximum continuous rating reached1 077t/h,the boiler efficiency was enhanced to 93.22%,and the steam temperature,steam pressure and steam flow rate all met the design requirements.However,due to low ash melting point,serious coking will occurred when burning Indonesia coal and Shenhun coal purely.It is recommended these two coals blending ratio be lower than 50%.

关 键 词：锅炉 燃烧器 受热面 结焦 烟煤 掺烧 数值模拟 制粉系统 

分 类 号：TK223.21[动力工程及工程热物理—动力机械及工程] TK16