蜂窝式SCR脱硝催化剂磨蚀研究
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摘要
对蜂窝式SCR(Selective Catalytic Reduction)催化剂磨蚀行为进行了研究,在实践的基础上结合侵蚀速率的经验表达式,提出了反应器内催化剂侵蚀速率及催化剂侵蚀承受系数β。其次,对催化剂磨蚀模型进行了研究,结合实践导出了催化剂综合磨蚀系数值及不同孔数催化剂的临界侵蚀速率。最后,分析了飞灰对催化剂磨蚀的影响及在飞灰作用下催化剂的壁厚减薄规律。结果表明,不同孔数的催化剂其承受烟气侵蚀的能力不同,孔数越少的催化剂侵蚀承受系数β值越大,反之越小;不同孔数的催化剂其综合磨蚀系数a_H不同,18孔、20孔催化剂其综合磨蚀系数a_H较其它催化剂低,但是其临界侵蚀速率EC/λ较其它催化剂高;飞灰中粗颗粒飞灰、不合理的飞灰级配、飞灰中Al_2O_3及SiO_2的含量、飞灰的入射角及在反应器内的灰场分布等是导致催化剂飞灰磨蚀的重要因素,当飞灰中Al_2O_3及SiO_2的含量超过80%、飞灰的入射角偏差超过±10°时,催化剂的磨蚀速率明显增加;当灰场分布偏差大于20%时,催化剂局部磨蚀速率明显增加,飞灰覆盖堵塞催化剂风险加大;通过飞灰作用下催化剂壁厚减薄的规律分析,总结提出了催化剂的磨蚀主要是烟气的入口效应引起,通过增加催化剂硬化段长度及提高硬化段硬化效果可以有效缓解催化剂磨蚀。
The abrasion behavior of honeycomb SCR(Selective Catalytic Reduction: SCR) catalyst was studied. Based on the practice and the empirical formula for the catalyst erosion rate,the catalyst erosion coefficient β was proposed. Then the catalyst abrasion model was researched. On the basis of mentioned above,the abrasion coefficient value and critical erosion rate of different cells catalysts were presented combined. Finally,the effect of fly ash on the catalyst attrition and the rule with the catalyst's wall thickness reduction on the fly ash were mainly analyzed. The result showed that the catalyst ability with different cells to withstand the flue gas erosion was diverse. The fewer the cells are,the stronger the catalyst erosion coefficient β is; otherwise it is weaker. The catalysts with different cells have diverse composite abrasion coefficient a_H. Catalysts with 18 cells and 20 cells have the lower composite abrasion coefficient a_Hthan others,but they had a higher critical erosion rate EC/λ than others. The important factors such as coarse particle fly ash,the unreasonable gradation of fly ash,Al_2O_3 and SiO_2 in fly ash,the incident angle of fly ash and the distribution in the reactor etc. will leading to the catalyst corrosion.When the percentage content of Al_2O_3 and SiO_2 in fly ash was more than 80% and the angle deviation was greater than ± 10°,the abrasion rate of catalyst increased significantly; when the distribution was greater than 20% for ash yard in the reactor,the Topo-abrasion rate of catalyst was significantly increased,and the risk about fly ash cover or jam catalyst was increased.Through the analysis of the discipline on wall thickness reduction of catalyst in the ash,the catalyst abrasion is caused mainly by entrance effect for the flue gas. By increasing the length and the quality of hardening mass,the catalyst abrasion in valid can be remitted.
The abrasion behavior of honeycomb SCR(Selective Catalytic Reduction: SCR) catalyst was studied. Based on the practice and the empirical formula for the catalyst erosion rate,the catalyst erosion coefficient β was proposed. Then the catalyst abrasion model was researched. On the basis of mentioned above,the abrasion coefficient value and critical erosion rate of different cells catalysts were presented combined. Finally,the effect of fly ash on the catalyst attrition and the rule with the catalyst's wall thickness reduction on the fly ash were mainly analyzed. The result showed that the catalyst ability with different cells to withstand the flue gas erosion was diverse. The fewer the cells are,the stronger the catalyst erosion coefficient β is; otherwise it is weaker. The catalysts with different cells have diverse composite abrasion coefficient a_H. Catalysts with 18 cells and 20 cells have the lower composite abrasion coefficient a_Hthan others,but they had a higher critical erosion rate EC/λ than others. The important factors such as coarse particle fly ash,the unreasonable gradation of fly ash,Al_2O_3 and SiO_2 in fly ash,the incident angle of fly ash and the distribution in the reactor etc. will leading to the catalyst corrosion.When the percentage content of Al_2O_3 and SiO_2 in fly ash was more than 80% and the angle deviation was greater than ± 10°,the abrasion rate of catalyst increased significantly; when the distribution was greater than 20% for ash yard in the reactor,the Topo-abrasion rate of catalyst was significantly increased,and the risk about fly ash cover or jam catalyst was increased.Through the analysis of the discipline on wall thickness reduction of catalyst in the ash,the catalyst abrasion is caused mainly by entrance effect for the flue gas. By increasing the length and the quality of hardening mass,the catalyst abrasion in valid can be remitted.
引文
[1]VGB-R302 He Guideline for the Testing of De NOx Catalysts,Germany,2010[S].
[2]EPRI Protocol for SCR Catalyst Testing,USA,2006[S].
[3]DL/T1286-2003,火电厂烟气脱硝催化剂检测技术规范[s].
[4]公涛.燃煤锅炉的飞灰磨损因素及防磨措施[J].企业技术开发,2014(8):179-180.
[5]GB/T31587-2015,蜂窝式烟气脱硝催化剂国家标准[S].
[6]肖雨亭,徐莉,贾曼,等.蜂窝式脱硝催化剂在烟气中的磨损行为的模拟研究[J].中国电力,2012,45(12):96-102.
[7]JUNG J,SCHAFER N.untersuchungen zum Abriebverhalten von De NOx-wabenkatalysatoren Zwischenbericht[R].Germany:Katalysatorenwerke huls Gmb KWH,1994.
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[9]李锋,於承志,张朋,等.高尘烟气脱硝催化剂耐磨性能研究[J].热力发电,2010,39(12):73-75.
[10]安敬学,王磊,秦淇,等.SCR脱硝系统催化剂磨损机理分析与治理[J].热力发电,2015(12):119-125.
[11]赵大周,何胜,郑文广,等.660MW机组SCR催化剂磨损分析及优化[J].发电与空调,2015,36(6):38-40.
[12]邓均慈,李德波.某电厂SCR脱硝催化剂严重磨损原因分析[J].热能动力工程,2014(5):580-585.
[13]张鸿,李国勇,车垚,等.600MW超临界机组脱硝催化剂损坏原因分析及对策[J].湖南电力,2015(1):48-50.
[14]邓静杰,韦红旗,仲亚飞,等.670MW机组SCR脱硝催化剂磨损的研究分析[J].电站系统工程,2015(4):58-60.
[15]徐秀林.SCR蜂窝状脱硝催化剂磨损研究[D].杭州:浙江大学,2015.
[16]罗睿.SCR脱硝反应器物理场特性研究与结构优化设计[D].长沙:长沙理工大学,2011.
[2]EPRI Protocol for SCR Catalyst Testing,USA,2006[S].
[3]DL/T1286-2003,火电厂烟气脱硝催化剂检测技术规范[s].
[4]公涛.燃煤锅炉的飞灰磨损因素及防磨措施[J].企业技术开发,2014(8):179-180.
[5]GB/T31587-2015,蜂窝式烟气脱硝催化剂国家标准[S].
[6]肖雨亭,徐莉,贾曼,等.蜂窝式脱硝催化剂在烟气中的磨损行为的模拟研究[J].中国电力,2012,45(12):96-102.
[7]JUNG J,SCHAFER N.untersuchungen zum Abriebverhalten von De NOx-wabenkatalysatoren Zwischenbericht[R].Germany:Katalysatorenwerke huls Gmb KWH,1994.
[8]秦福初.SCR脱硝催化剂抗磨损性能研究[C]//中国环境科学学会学术年会论文集(第二卷),2015.
[9]李锋,於承志,张朋,等.高尘烟气脱硝催化剂耐磨性能研究[J].热力发电,2010,39(12):73-75.
[10]安敬学,王磊,秦淇,等.SCR脱硝系统催化剂磨损机理分析与治理[J].热力发电,2015(12):119-125.
[11]赵大周,何胜,郑文广,等.660MW机组SCR催化剂磨损分析及优化[J].发电与空调,2015,36(6):38-40.
[12]邓均慈,李德波.某电厂SCR脱硝催化剂严重磨损原因分析[J].热能动力工程,2014(5):580-585.
[13]张鸿,李国勇,车垚,等.600MW超临界机组脱硝催化剂损坏原因分析及对策[J].湖南电力,2015(1):48-50.
[14]邓静杰,韦红旗,仲亚飞,等.670MW机组SCR脱硝催化剂磨损的研究分析[J].电站系统工程,2015(4):58-60.
[15]徐秀林.SCR蜂窝状脱硝催化剂磨损研究[D].杭州:浙江大学,2015.
[16]罗睿.SCR脱硝反应器物理场特性研究与结构优化设计[D].长沙:长沙理工大学,2011.