发电技术 ›› 2025, Vol. 46 ›› Issue (5): 1005-1013.DOI: 10.12096/j.2096-4528.pgt.25027

• 发电及环境保护 •    

纯燃高碱煤循环流化床锅炉宽负荷低NO x 燃烧改造试验研究

王洪健1, 黄延凯2, 喻鑫2, 于敦喜2   

  1. 1.新疆东方希望有色金属有限公司,新疆维吾尔自治区 昌吉回族自治州 831700
    2.煤燃烧国家重点实验室(华中科技大学),湖北省 武汉市 430074
  • 收稿日期:2025-01-09 修回日期:2025-03-10 出版日期:2025-10-31 发布日期:2025-10-23
  • 作者简介:王洪健(1978),男,工程师,研究方向为新疆高碱煤燃烧发电及循环流化床锅炉发电管理,379694550@qq.com
    黄延凯(1997),男,博士研究生,研究方向为低阶燃料的燃烧特性及其污染物的排放控制,laiwuhyk@163.com
    喻鑫(1990),男,博士,助理研究员,研究方向为固体燃料清洁高效利用,xinyu@hust.edu.cn
    于敦喜(1975),男,博士,教授,研究方向为煤/生物质等含碳能源、氢/氨等富氢能源的清洁高效利用理论与技术,本文通信作者,yudunxi@hust.edu.cn
  • 基金资助:
    国家重点研发计划项目(2023YFB4102703)

Experimental Study on Wide-Load Low-NO x Combustion Retrofit for Circulating Fluidized Bed Boiler Burning High-Alkali Coal

Hongjian WANG1, Yankai HUANG2, Xin YU2, Dunxi YU2   

  1. 1.Xinjiang East Hope Nonferrous Metals Co. , Ltd. , Changji Hui Autonomous Prefecture 831700, Xinjiang Uygur Autonomous Region, China
    2.State Key Laboratory of Coal Combustion (Huazhong University of Science and Technology), Wuhan 430074, Hubei Province, China
  • Received:2025-01-09 Revised:2025-03-10 Published:2025-10-31 Online:2025-10-23
  • Supported by:
    National Key Research and Development Program of China(2023YFB4102703)

摘要:

目的 新疆地区某440 t/h纯燃高碱煤循环流化床(circulating fluidized bed,CFB)锅炉在运行过程中发现其NO x 排放不达标,为此,开展了针对该锅炉的低NO x 燃烧改造试验研究。 方法 通过改造锅炉部件和调整运行参数来降低NO x 排放:为提高分离器效率进而降低锅炉平均床温,在水冷壁上适当扩展受热面和提高分离器的入口速度;为优化二次风,对二次风口高度进行了调整;为创造还原性气氛,增加了烟气再循环系统。 结果 通过综合改造措施,显著降低了锅炉平均床温和炉膛烟温,有效降低了烟气中O2含量,创造了更有利于抑制NO x 生成的均匀温度场和还原性气氛,最终降低了NO x 的生成和排放。 结论 改造后,在宽负荷条件下,即使不使用选择性非催化还原(selective non-catalytic reduction,SNCR)技术,也实现了NO x 的超低排放(低于40 mg/m3)。此次改造实践对于现役CFB锅炉低NO x 燃烧控制具有积极影响和借鉴意义。

关键词: 纯燃高碱煤, 循环流化床(CFB)锅炉, 锅炉改造, 低NO x 燃烧, 超低排放, 宽负荷, 还原性气氛

Abstract:

Objectives During the operation of a 440 t/h circulating fluidized bed (CFB) boiler burning high-alkali coal in Xinjiang, China, it is found that its NO x emissions do not meet the standard. Consequently, an experimental study for low-NO x combustion retrofit is conducted on this boiler. Methods NO x emissions are reduced through boiler component modifications and operational parameter adjustments. To enhance separator efficiency and thereby lower the average bed temperature of the boiler, the heating surface of the water-cooled wall is appropriately extended, and the inlet velocity of the separator is increased. The secondary air is optimized by adjusting the height of the secondary air nozzles. To create a reducing atmosphere, a flue gas recirculation system is added. Results Through comprehensive transformation measures, the average bed temperature and furnace flue gas temperature of the boiler are significantly reduced, and the O2 content in the flue gas is effectively decreased. A more uniform temperature field and a reducing atmosphere are created, both of which are conducive to suppressing NO x formation, thereby reducing NO x generation and emissions. Conclusions Following the retrofit, ultra-low NO x emissions (below 40 mg/m3) are achieved under wide-load conditions even without employing selective non-catalytic reduction (SNCR). This retrofit practice holds positive implications and reference value for low-NO x combustion control in existing CFB boilers.

Key words: pure burning of high-alkali coal, circulating fluidized bed (CFB) boiler, boiler retrofit, low-NO x combustion, ultra-low emissions, wide load, reducing atmosphere

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