MICROMIXER IMPROVEMENT AND VERIFICATION FOR AN SCR DENITRATION SYSTEM OF A 330 MW COAL-FIRED POWER UNIT BASED ON CFD
-
摘要: 为探明混合器形式对于燃煤机组SCR脱硝系统性能的影响,运用数值三维模拟对330 MW燃煤机组SCR脱硝系统烟道中烟气流动速度、温度、氨浓度以及流动方向进行了模拟计算,并采用物理模型对数值模拟结果进行验证。对比研究了使用不同形式混合器上下游速度场、NH3浓度场、压力损失及加工难度。结果表明:梯形板混合器加工简单、扰动范围大、压力损失大、对下游速度场影响大;扭叶片式混合器阻力小、对下游速度场几乎没有影响,但扰动范围小、安装角度要求高;六角星形混合器综合性能介于梯形板及扭叶片式混合器之间。六角星形混合器能够较好地实现NH3与烟气混合,下游速度场均匀性及NH3浓度均匀性满足设计要求。Abstract: In this paper, the flow velocity, temperature, ammonia concentration, and flow direction of flue gas in the SCR denitration system of a 330 MW coal-fired power unit were simulated by three-dimensional numerical simulation, and then the numerical simulation results were verified by a physical model. The results showed that the trapezoidal micromixer had the advantages of simple processing, large disturbance range, large pressure loss, and great influence on the downstream velocity field; the twisted vane micromixer had lower resistance and effect on the downstream velocity field, but smaller disturbance range and higher requirements on the installation angle. The comprehensive performance of hexagonal micromixer was between trapezoidal micromixer and twisted vane micromixer. The hexagonal micromixer could better realize the mixing of NH3 and flue gas, and the uniformity of downstream velocity field and NH3 concentration met the design requirements.
-
Key words:
- SCR /
- flow field improvement /
- CFD numerical simulation /
- micromixer
-
[1] 王瑜. SCR法烟气脱硝系统在660 MW火电机组中的应用[D]. 北京:华北电力大学(北京), 2013. [2] 沈丹, 李大梅, 杨蕾,等. 电厂SCR脱硝数值模拟技术研究进展[J]. 能源环境保护, 2013, 27(3):10-13. [3] 苑广存. 500 MW机组脱硝系统喷氨格栅优化设计[J]. 锅炉技术,2019,50(6):8-12. [4] 雷鉴琦. 超低排放SCR烟气脱硝系统的优化分析[J]. 锅炉技术,2019,50(2):76-80. [5] 周国民,付鹏,王富强,等. 燃煤电站锅炉脱硝精准喷氨技术研究及应用[J]. 锅炉技术,2020,51(6):73-79. [6] 郭婷婷, 刘汉强, 杨勇平,等. 基于数值模拟的1000 MW燃煤机组SCR脱硝系统设计[J]. 电站系统工程, 2010, 26(5):61-64. [7] 高飞,邹红果. 烟气流场分布对SCR系统的影响及其优化措施[J]. 环境工程, 2019,37(10):153-156. [8] 杨超, 张杰群, 郭婷婷. SCR烟气脱硝装置烟气流场数值模拟[J]. 东北电力大学学报, 2012, 32(1):66-70. [9] YIM S D, KIM S J, BAIK J H, et al. Decomposition of urea into NH3 for the SCR process[J]. Industrial & Engineering Chemistry Research, 2004, 43(16):4856-4863. [10] 朱天宇, 李德波, 方庆艳,等. 燃煤锅炉SCR烟气脱硝系统流场优化的数值模拟[J]. 动力工程学报, 2015, 35(6):481-488. [11] BAXTER L L. Turbulent transport of particles[D]. Brigham Young University, Provo, Utah.1989. [12] JAIN S. Three-dimensional simulation of turbulent particle dispersion[D]. University of Utah, Utah, 1995. [13] BRUCATO A, GRISAFI F, MONTANTE G. Particle drag coefficients in turbulent fluids[J]. Chemical Engineering Science, 1998, 53(18):3295-3314. [14] LAUNDER B E, SPALDING D B. The numerical computation of turbulent flows[J]. Computer Methods in Applied Mechanics & Engineering, 1974, 3(2):269-289.
点击查看大图
计量
- 文章访问数: 110
- HTML全文浏览量: 12
- PDF下载量: 6
- 被引次数: 0