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J4  2010, Vol. 44 Issue (4): 750-755    DOI: 10.3785/j.issn.1008-973X.2010.04.022
热能工程、动力与电气工程     
大型燃煤锅炉SNCR过程数值研究
吕钰, 王智化, 杨卫娟, 周俊虎, 何沛, 岑可法
浙江大学 热能工程研究所,能源清洁利用国家重点实验室,浙江 杭州 310027
Numerical study of SNCR process in coalfired boiler with large capacity
LV Yu, WANG Zhi-hua, YANG Wei-juan, ZHOU Jun-hu, HE Pei, CEN Ke-fa
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摘要:

基于Fluent软件平台,对410 t/h燃煤锅炉中选择性非催化还原(SNCR)过程进行建模和模拟计算.计算结果与实验测量数据吻合很好,阐明了利用这种方法预测大空间、复杂温度场、复杂流场的锅炉炉膛中氮氧化物生成及还原过程的可行性.计算结果表明,在还原剂与氮氧化物初期混合条件有限的情况下,脱硝效果决定于物质的湍流扩散和温度场之间的相互作用.研究在不同喷射截面上温度和氨氮摩尔比对SNCR过程的影响,结果表明喷射截面应该取在平均温度位于SNCR“温度窗口”中部的截面所对应的高度处,在该工况下脱硝率在42%以上,且随氨氮摩尔比由1.0提高到2.2,脱硝率增长约58%.综合考虑尾部漏氨,氨氮摩尔比应该控制在1.4以下.

Abstract:

Modeling and numerical simulation for the selective noncatalytic reduction (SNCR) process in a 410 t/h coalfired boiler were conducted based on the Fluent software. Good agreement of the calculation results with the data measured in field experiment confirms the feasibility of the presented method for predicting the NOx formation and reduction processes in the furnace with large capacity, complex temperature field and complex flow field. The simulation shows that the NOx removal effect largely depends on the interaction between turbulence diffusion and temperature field, in the case that the reagent’s original mixing with NOx is quite limited. The influence of temperature level and NH3/NO molar ratio in different injecting crosssections on the SNCR process was studied. The results show that the injecting crosssection should be placed at the corresponding height of the crosssection whose temperature located in the middle of the SNCR “temperature window”. In this state, the NOx removal efficiency is above 42%, and it increases approximately by 58% when NH3/NO molar ratio rises from 1.0 to 2.2. However, considering the NH3 leakage in the empennage area simultaneously, NH3/NO molar ratio should be controlled bellow 1.4.

出版日期: 2010-05-14
:  TK229  
基金资助:

国家杰出青年科学基金资助项目(50525620)

通讯作者: 王智化,男,副教授.     E-mail: wangzh@zju.edu.cn
作者简介: 吕钰(1985—),男,山东潍坊人,硕士生,从事燃煤NOx控制及数值计算方面的研究. E-mail: Lvyu1985@gmail.com
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引用本文:

吕钰, 王智化, 杨卫娟, 周俊虎, 何沛, 岑可法. 大型燃煤锅炉SNCR过程数值研究[J]. J4, 2010, 44(4): 750-755.

LV Yu, WANG Zhi-Hua, YANG Wei-Juan, ZHOU Dun-Hu, HE Pei, CEN Ge-Fa. Numerical study of SNCR process in coalfired boiler with large capacity. J4, 2010, 44(4): 750-755.

链接本文:

http://www.zjujournals.com/eng/CN/10.3785/j.issn.1008-973X.2010.04.022        http://www.zjujournals.com/eng/CN/Y2010/V44/I4/750

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