600MW超临界燃煤锅炉燃烧优化的数值模拟
发布时间：2019-01-06 11:47
【摘要】：我国能源结构中煤炭的主体地位在较长的时间内不会改变,提高能源即煤炭的燃烧利用效率及减少污染是当下关注的焦点问题之一。超临界锅炉具备了解决这两方面问题的能力,在燃煤电厂中广泛采用。本文针对某超临界对冲锅炉,利用FLUENT软件对该锅炉不同工况进行数值模拟,确定最佳参数,从而实现燃烧优化的目的。 本文选用的模型载体为某电厂型号为DG2090/25.4-117的超临界直流锅炉,依托数值模拟软件,进行炉内各过程模拟研究。对于气固两相间气相湍流计算采用RNG k-ε模型；对于煤颗粒挥发分的释放采用了双方程竞争反应模型；对于气相湍流燃烧采用混合分数-概率密度函数模型；对于焦炭燃烧采用运动／扩散控制燃烧模型；对于锅炉内辐射换热采用P-1辐射模型；对于煤颗粒的轨迹采用随机颗粒轨道模型；最后介绍了离散相与连续相之间的耦合计算模型。 首先,对该锅炉100%BMCR工况进行模拟,对炉内速度场、温度场、氧气浓度分布及NO浓度分布进行了详尽的讨论,总结了前后墙对冲锅炉燃烧特点,理论上证明模拟结果的准确性,计算结果炉膛出口温度与NO排放浓度与锅炉实际运行数据对比基本符合,证明模拟结果可以较完整的反映实际运行,从而可以对变工况进行深入研究。其次,本文通过改变旋流二次风的旋流强度、过量空气系数及燃尽风风率,分析这些参数对锅炉安全运行、燃烧效率及NO排放量的影响,从而得到合理参数,为锅炉安全经济运行提供参考。
[Abstract]:The dominant position of coal in China's energy structure will not change for a long time. One of the focus problems is to improve the efficiency of coal combustion and reduce pollution. Supercritical boilers have the ability to solve these two problems and are widely used in coal-fired power plants. In this paper, for a supercritical hedging boiler, the numerical simulation of the boiler under different working conditions is carried out by using FLUENT software, and the optimum parameters are determined to realize the purpose of combustion optimization. The model carrier selected in this paper is a supercritical once-through boiler with DG2090/25.4-117 model in a power plant. The numerical simulation software is used to simulate each process in the boiler. RNG k- 蔚 model is used for gas-solid two-phase turbulence calculation, two-equation competitive reaction model is used for the release of volatile matter from coal particles, and mixed fracture-probability density function model is used for gas-phase turbulent combustion. Motion / diffusion controlled combustion model is used for coke combustion, P-1 radiation model is used for radiative heat transfer in boiler, random particle orbit model is used for coal particle trajectory. Finally, the coupling calculation model between discrete phase and continuous phase is introduced. Firstly, the 100%BMCR operating conditions of the boiler are simulated, and the velocity field, temperature field, oxygen concentration distribution and NO concentration distribution in the boiler are discussed in detail, and the combustion characteristics of the front and rear wall hedge boiler are summarized. The accuracy of the simulation results is proved theoretically, and the comparison between the furnace outlet temperature and the NO emission concentration and the actual operation data of the boiler is basically consistent. It is proved that the simulation results can reflect the actual operation more completely. Thus, it is possible to carry on the thorough research to the variable working condition. Secondly, by changing the swirl intensity, excess air coefficient and burnout air rate of swirl secondary air, the effects of these parameters on boiler safe operation, combustion efficiency and NO emission are analyzed, and the reasonable parameters are obtained. It provides reference for safe and economical operation of boiler.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM621.2
本文编号：2402751
[Abstract]:The dominant position of coal in China's energy structure will not change for a long time. One of the focus problems is to improve the efficiency of coal combustion and reduce pollution. Supercritical boilers have the ability to solve these two problems and are widely used in coal-fired power plants. In this paper, for a supercritical hedging boiler, the numerical simulation of the boiler under different working conditions is carried out by using FLUENT software, and the optimum parameters are determined to realize the purpose of combustion optimization. The model carrier selected in this paper is a supercritical once-through boiler with DG2090/25.4-117 model in a power plant. The numerical simulation software is used to simulate each process in the boiler. RNG k- 蔚 model is used for gas-solid two-phase turbulence calculation, two-equation competitive reaction model is used for the release of volatile matter from coal particles, and mixed fracture-probability density function model is used for gas-phase turbulent combustion. Motion / diffusion controlled combustion model is used for coke combustion, P-1 radiation model is used for radiative heat transfer in boiler, random particle orbit model is used for coal particle trajectory. Finally, the coupling calculation model between discrete phase and continuous phase is introduced. Firstly, the 100%BMCR operating conditions of the boiler are simulated, and the velocity field, temperature field, oxygen concentration distribution and NO concentration distribution in the boiler are discussed in detail, and the combustion characteristics of the front and rear wall hedge boiler are summarized. The accuracy of the simulation results is proved theoretically, and the comparison between the furnace outlet temperature and the NO emission concentration and the actual operation data of the boiler is basically consistent. It is proved that the simulation results can reflect the actual operation more completely. Thus, it is possible to carry on the thorough research to the variable working condition. Secondly, by changing the swirl intensity, excess air coefficient and burnout air rate of swirl secondary air, the effects of these parameters on boiler safe operation, combustion efficiency and NO emission are analyzed, and the reasonable parameters are obtained. It provides reference for safe and economical operation of boiler.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM621.2
【参考文献】
相关期刊论文 前6条
1 王丽英;大型锅炉墙置对冲燃烧技术[J];华东电力;2002年09期
2 熊蔚立;黄伟;彭敏;;超临界锅炉技术特点及发展方向[J];湖南电力;2008年04期
3 方庆艳;汪华剑;陈刚;周怀春;;燃尽风对超超临界锅炉燃烧特性影响的数值模拟[J];华中科技大学学报(自然科学版);2010年11期
4 朱彤,范卫东,信伟,陈力哲,吴少华,秦裕琨;双炉膛炉内空气动力场的数值模拟研究[J];热能动力工程;1997年06期
5 岑可法,樊建人;数值试验(CAT)在大型电站锅炉设计及调试中应用的前景——(Ⅰ)基础理论[J];浙江大学学报(自然科学版);1992年01期
6 岑可法,樊建人;数值试验(CAT)在大型电站锅炉设计及调试中应用的前景——(Ⅱ)应用实例[J];浙江大学学报(自然科学版);1992年02期
，本文编号：2402751
本文链接：https://www.wllwen.com/kejilunwen/dianlilw/2402751.html
教材专著
