含水率阈值下的煤泥掺烧特性及600 MW机组模拟验证

Characteristics of Coal Slime Co-Combustion Under Moisture Threshold Constraints and Simulation Verification in a 600MW Unit

摘要

采用热重分析与数值仿真方法,研究了煤泥混燃的科学性和可行性．首先,采用热重分析法对15种烟煤和褐煤样品以及两种煤泥样品(分别配置10种不同含水率)在不同升温速率和粒径条件下进行了燃烧特性测试,确定了各类燃料的关键燃烧特性参数．结果表明,含水率30%是煤泥燃烧性能的临界点,超过该值后,燃烧性能显著下降,降幅达30.50%～45.65%．在此界限条件下测试了煤泥与9种烟煤的掺烧性能,确定煤泥最佳掺烧比例为10%．后续还针对煤泥在对冲燃烧方式锅炉较少这一研究现状,以600 MW某π型单炉膛、一次中间再热锅炉为研究对象,在误差6%范围内试验结果与模拟结果相吻合,研究发现煤泥的引入可降低NO_x的生成,但是掺烧比例过高后会造成SO₂局部过高,综合来看100%BMCR工况下煤泥掺烧比例建议为10%,相关数据可为煤泥掺烧提供良好的参考．

Abstract

This study investigates the scientific and practical feasibility of coal slime co-combustion through thermogravimetric analysis(TGA)and numerical simulation. First,combustion characteristic parameters were determined for 15 types of bituminous and lignite coals,as well as two types of coal slime samples,each prepared with ten different moisture contents,under varying heating rates and particle sizes. The analysis quantitatively revealed that the moisture content of 30% serves as a critical threshold for slime combustion characteristics,beyond which combustion performance drops significantly by 30.50%—45.65%. Under this threshold,co-combustion experiments with slime and nine bituminous coals identified an optimal slime blending ratio of 10%. To address the limited research on slime application in opposed-fired boilers,a 600 MW π-type single-furnace,one-time intermediate reheat boiler was selected for validation.The test results within an error range of 6% were consistent with the simulation results. The study found that the introduction of coal slime can reduce the generation of NO_x,but if the co-combustion ratio is too high,it will cause local excessive SO₂. Overall,the recommended co-combustion ratio of coal slime under the 100%BMCR condition is 10%. Relevant data can provide a good reference for the co-combustion of coal slime.

关键词

煤泥掺烧 / 热重分析 / 燃烧动力学 / 含水率阈值 / 燃煤机组

Key words

coal slime co-combustion / thermogravimetric analysis / combustion kinetics / moisture content threshold / coal-fired power unit

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基金资助

国家能源集团科学技术研究院有限公司科技资助项目(SY2023Y01)