• 论文
主办单位:煤炭科学研究总院有限公司、中国煤炭学会学术期刊工作委员会
氨/煤气流床半气化燃烧及氮转化特性实验研究
  • Title

    An experimental study on the characteristics of ammonia/coal mild gasification-combustion and the Fuel-N transformation

  • 作者

    崔保崇王肖肖舒逸翔林辉谭厚章王学斌

  • Author

    CUI Baochong;WANG Xiaoxiao;SHU Yixiang;LIN Hui;TAN Houzhang;WANG Xuebin

  • 单位

    西安交通大学热流科学与工程教育部重点实验室

  • Organization
    MOE Key Laboratory of Thermo-Fluid Science and Engineering, Xi’an Jiaotong University
  • 摘要

    氨气(NH3)作为零碳富氢燃料,在燃煤锅炉中掺烧NH3是从燃烧源减少碳排放的有效途径,但会带来NOx排放升高和煤粉燃尽变差等问题。为实现燃煤锅炉掺烧NH3的低NOx排放,在自行搭建的气流床半气化燃烧实验台上探究了气化炉掺烧20%的NH3(G-20%NH3)和燃烧室掺烧20%的NH3(C-20%NH3)中燃料氮的转化和NOx排放特性。研究发现,气化炉内掺烧NH3会降低炉膛温度,但对煤粉的气化反应影响较小,与纯煤工况相比,煤氮的转化率仅降低了3.64%,挥发分和固定碳转化率分别仅降低了0.70%和2.54%。在气化炉掺烧NH3中,NH3在气化炉中的转化率可达69.55%。气化炉内总燃料氮向N2的转化率为68.88%,其中NH3-N向N2的转化率为67.73%。同时,气化炉掺烧NH3促进了煤-N和NH3-N向HCN的转化,转化率为0.36%。气化炉中煤粉的热解促进了NH3的热解,相较于纯煤,气化炉掺烧NH3使气化炉出口H2体积分数升高了69.23%。掺烧NH3降低了燃烧室燃烧初期的温度分布。相较于纯煤,气化炉和燃烧室掺烧NH3使燃烧室的温度峰值分别降低了46 ℃和62 ℃。但是,掺烧NH3推迟了气化半焦的燃烧,增加了燃尽区的温度。气化炉和燃烧室掺烧NH3中燃尽区平均温度比纯煤工况分别升高了135.8 ℃和72.8 ℃,促进了煤粉的燃尽。其中燃烧室掺烧NH3的促进效果更为显著,相较于纯煤,C-20%NH3中飞灰含碳降低了1.8%。但气化炉掺烧NH3更有利于降低NOx排放,相较于C-20%NH3,G-20%NH3的NO排放降低了23.51%。

  • Abstract

    Ammonia (NH3) is a carbon-free and hydrogen-rich fuel. NH3 co-firing in coal-fired boiler is an effective approach to reduce carbon emissions from the combustion source. However, it can lead to problems such as high NOx emissions and poor coal burnout. To address the issues above, this paper investigated the Fuel-N conversion and NOx emissions during co-firing 20%NH3 in gasifier (G-20% NH3) and in combustor (C-20%NH3) using a self-built mild gasification-combustion experimental rig. The research found that the co-firing NH3 in the gasifier can decrease the gasifier temperature. However, it has little effect on the coal gasification reactions in gasifier. Compared with a pure coal condition, the conversion ratio of coal-nitrogen was only reduced by 3.64%, and the conversion ratio of volatile matter and fixed carbon decreased by only 0.70% and 2.54%, respectively. Besides, the conversion of NH3 in the gasifier can reach 69.55% during the condition of G-20%NH3. The 68.88% of total fuel-N was conversed to N2 in the gasifier, with NH3-N converting to N2 was 67.73% in G-20%NH3. In addition, the NH3 co-firing in the gasifier promoted the transformation of coal-N and NH3-N to HCN, with the value of 0.36%. Moreover, the coal pyrolysis in the gasifier promoted the NH3 pyrolysis. Compared with pure coal, the NH3 co-firing in the gasifier increased the H2 concentration at the outlet of the gasifier by 69.23% than that of pure coal. The NH3 co-firing also decreased the temperature during the preliminary stage of combustion. Compared with pure coal, the NH3 co-firing in the gasifier and combustor decreased the temperature peak by 46 ℃ and 62 ℃, respectively. Simultaneously, the NH3 co-firing delayed the occurrence of temperature peaks. Additionally, the NH3 co-firing delayed the gasified char combustion in the combustor. The average temperature in the burnout zone increased by 135.8 ℃ and 72.8 ℃ during G-20%NH3 and C-20%NH3, respectively, compared to PC. It was more conducive to the burnout of pulverized coal. The NH3-cofiring in combustor had more significant promoting effects on the burnout of pulverized coal, in which the unburned carbon in fly ash decreased by 1.8% compared PC. However, the NH3 co-firing in gasifier was more effective in reducing NOx emissions. During the G-20%NH3, NO emissions were decreased by 23.51% compared to C-20%NH3. The study offers some innovative ideas and data reference for the development of low NOx emission technology for NH3 co-firing in coal-fired boiler.

  • 关键词

    氨/煤混燃半气化–燃烧特性燃料氮转化NOx排放特性

  • KeyWords

    ammonia/coal co-firing;mild Gasification-combustion characteristics;Fuel-N transformation;NOx emission

  • 基金项目(Foundation)
    国家重点研发计划资助项目 (2022YFB4100500)
  • DOI
  • 引用格式
    崔保崇,王肖肖,舒逸翔,等. 氨/煤气流床半气化燃烧及氮转化特性实验研究[J]. 煤炭学报,2024,49(10):4275−4283. DOI: 10.13225/j.cnki.jccs.LC24.0135
  • Citation
    CUI Baochong,WANG Xiaoxiao,SHU Yixiang,et al. An experimental study on the characteristics of ammonia/coal mild gasification-combustion and the Fuel-N transformation[J]. Journal of China Coal Society,2024,49(10):4275−4283. DOI: 10.13225/j.cnki.jccs.LC24.0135
  • 相关专题
  • 图表
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    • 原煤粒径分布

    图(11) / 表(3)

相关问题

主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会

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