化工学报 ›› 2012, Vol. 63 ›› Issue (8): 2544-2550.DOI: 10.3969/j.issn.0438-1157.2012.08.029

• 能源和环境工程 • 上一篇    下一篇

130t煤粉炉内煤制气还原NOx的反应机理与CFD耦合计算

党帅,钟北京,袁振   

  1. 热科学与动力工程教育部重点实验室,清华大学航天航空学院,北京100084
  • 收稿日期:2011-11-14 修回日期:2012-03-18 出版日期:2012-08-05 发布日期:2012-08-05
  • 通讯作者: 钟北京

Reduction mechanism of NOx by coal gas produced in a 130 t powder coal burner and coupling CFD calculation

DANG Shuai,ZHONG Beijing,YUAN Zhen   

  • Received:2011-11-14 Revised:2012-03-18 Online:2012-08-05 Published:2012-08-05

摘要: 在没有气源的电厂,可以采用煤制气再燃低NOx燃烧技术,即采用空气和水蒸气作为气化介质,在1000℃以下进行气化得到煤制气,实现部分煤气化再燃低NOx燃烧技术。本文选用GRI3.0反应机理,简化后得到了适用于NOx还原计算的简化机理,包括26个组分和63个反应,对130 t煤粉炉进行了多步反应机理和CFD耦合计算的尝试,并对还原气喷口和还原气比例进行了设计计算,提出了改造设计方案,可实现NOx还原率超过80%。计算结果表明,采用部分煤制成再燃气燃烧没有明显影响煤的燃尽率;130 t煤粉炉设计的三次风喷口应该上移3 m,以增加再燃反应时间;再燃气比例可设计为30%,以增加NOx还原效果。

关键词: 煤制气, NOx还原, 反应动力学, 耦合计算

Abstract: In power plants having no gas source,a feasible option is that re-burning of coal gas produced in powder coal burner to reduce emission of NOxi.e.in order to the coal gas,using air and water vapor as medium to gasify a part of coal below 1000℃.In this paper GRI3.0 mechanism is selected and after simplifying a multi-step mechanism including 26 species and 63 reactions is got for simulating a 130 t powder coal burner.The design calculation of the inlet and the ratio of re-burning gas are done and a alteration design that can make 80% reduction of NOx is proposed.The results show that the re-burning does not have significant influence on burnout ratio of coal.The inlet of the third air wind should be moved up 3 m to increase the reduction time of NOx.The ratio of re-burning gas should be controlled at 30% to strengthen its reduction performance.

Key words: coal gas, NOx reduction, kinetic analysis, coupling calculation