NUMERICAL SIMULATION FOR FGD WASTEWATER EVAPORATION IN THE FLUE DUCT OF A 2×350 MW COAL-FIRED UNIT
-
摘要: 针对某2×350 MW燃煤发电机组主烟道脱硫废水蒸发过程进行了CFD数值模拟,分析了蒸发过程中烟道内的气液分布和变化规律,喷嘴参数对蒸发性能的影响,以及蒸发过程随着负荷降低的变化规律。结果表明:液滴颗粒可在烟道内完全蒸发;粒径从40 μm增加到80 μm时,液滴蒸发时间从0.26 s增加到0.62 s,蒸发距离从6.15 m增加到13.41 m;蒸发时间和蒸发距离与液滴粒径近似呈线性关系;蒸发时间随着喷射角度的增加而减小;喷射角度为90°时,蒸发距离最短;喷射角度为120°时,蒸发距离最大;3种喷射方向中,逆流喷射方式蒸发时间最长,但蒸发距离最短;负荷降低,蒸发时间增加;负荷由75%降低至50%时,蒸发距离有显著提升。Abstract: A series of numerical simulations were conducted for FGD wastewater evaporation occurred in a flue duct of a 2×350 MW coal-fired unit. The evolution and distribution of gas-liquid was revealed and the dependence of residence time and required distance for evaporation on spray parameters and unit load was discussed. The results showed that the liquid droplet could evaporate completely as the droplet diameter was less than 80 μm; while the diameter of liquid droplet increased from 40 μm to 80 μm, the residence time for evaporation increased from 0.26 s to 0.62 s and the required distance for droplet evaporating completely increased from 6.15 m to 13.41 m; the residence time and required distance for evaporation had a linear relation with the droplet diameter. It also presented that enhancing the injection-angle decreased the residence time of evaporation; as the injection-angle was 90°, the required distance of evaporation was the largest; in contrast, when the injection-angle was 120°, the required distance of evaporation was the smallest; while the injection-direction was opposite to the flow direction of flue gas, the residence time of evaporation was the longest and required distance of evaporation was the shortest in the three cases; the residence time of evaporation was larger with a lower load; an obvious increase in the required distance of evaporation was observed with the load dropping from 75% to 50%.
-
Key words:
- coal-fired unit /
- FGD wastewater /
- evaporation /
- numerical simulation
-
吴怡卫. 石灰石-石膏湿法烟气脱硫废水处理的研究[J]. 中国电力, 2006, 39(4): 75-78. 刘绍银. 火电厂湿法烟气脱硫废水处理若干问题的探讨[J]. 热力发电, 2008, 37(11): 121-122. HIGGINS T E, THOMAS S A, GIVENS S W. Flue gas desulfurization wastewater treatment primer[J]. Power, 2009, 153(3): 40-43. ENOCH G D, SPIERING W, TIGCHELAAR P, et al. Treatment of waste water from wet lime (stone) flue gas desulfurization plants with aid of crossflow microfiltration[J]. Separation Science, 1990, 25(13/14/15): 1587-1605. 李明波,范玺,孙克勤.利用烟道气处理火电厂WFGD废水的技术应用[J].电力科技与环保,2010, 26(2): 53-55. 刘海洋,江澄宇,谷小兵,等. 燃煤电厂湿法脱硫废水零排放处理技术进展[J].水污染防治, 2016, 34(4): 33-36. 王晓焙, 耿宣, 罗天翔, 等.330 MW机组脱硫废水旁路烟道喷雾干燥技术数值模拟与应用示范[J].热力发电, 2019,48(6):96-101. 马双忱, 柴峰, 吴文龙, 等. 脱硫废水烟道喷雾蒸发的数值模拟[J]. 计算机与应用化学, 2016,33(1): 47-53. 张子敬, 汪建文, 高艺, 等. 燃煤电厂脱硫废水烟气蒸发特性流场模拟[J]. 煤炭学报, 2015, 40(3): 678-683. DENG J J, PAN L M, CHEN D Q, et al. Numerical simulation and field test study of desulfurization wastewater evaporation treatment through flue gas[J]. Water Science and Technology, 2014, 70(7): 1285-1291. 冉景煜,张志荣.不同物性液滴在低温烟气中的蒸发特性数值研究[J].中国电机工程学报, 2010, 30(26): 62-68. 晋银佳,王帅,姬海宏,等.深度过滤-烟道蒸发处理脱硫废水的数值模拟[J].中国电力, 2016, 49(12): 174-179. PINTO M, KEMP I, BERMINGHAM S, et al. Development of an axisymmetric population balance model for spray drying and validation against experimental date and CFD simulation[J]. Chemical Enginerering Research & Design, 2014, 92(4): 619-634. BORODULIN V Y, LETUSHKO V N, NIZOVTSEV M I, et al. Determination of parameters of heat and mass transfer in evaporating drops[J]. International Journal of Heat and Mass Transfer, 2017, 109: 609-618. RA Y, REITZ R D. A vaporization model for discrete multi-component fuel sprays[J]. International Journal of Multiphase Flow, 2009, 35(2):101-117. -
![WeChat](/fileGYJZ_HJGC/journal/article/hjgc/2020/5/WECHAT/wechat_cn_f785ef51-16a4-4088-a6ba-42aec05cb827.jpg)
计量
- 文章访问数: 137
- HTML全文浏览量: 18
- PDF下载量: 5
- 被引次数: 0