Numerical evaporation characteristics of desulfurization wastewater by rotating spray with different hot air distributor structure

doi:10.16085/j.issn.1000-6613.2020-0867

Abstract

Abstract:

A two-phase flow model for gas and liquid including the heat and mass transfer between them was established, and the desulfurization wastewater spray evaporation process in a 300MW power plant was studied by simulation. The influence of angle and number of deflectors on the flow field in drying tower and the movement and evaporation of wastewater droplets was investigated. The results showed that the influence of the angle of outer deflectors on the flow field in the drying tower is greater than that of the inner deflectors. With the increase of the angle of outer deflectors, the rotation effect of flue gas entering the spray drying tower is more obvious, and the rotation effect of flue gas is the best when it is 32°. With the increase of the angle of inner deflectors, the maximum distance of droplets axial movement decreases. Meanwhile, the change of the angle of inner deflectors has a greater influence on the complete evaporation time of the droplets in drying tower than that of the outer deflectors, and the evaporation time of droplets is the shortest when the angle of inner deflectors is 0°. The number of inner deflectors has little influence on the flow field, droplet movement or evaporation in the drying tower. With the increase of the number of inner deflectors, the flow field, droplets movement distance and complete evaporation time in the drying tower tend to be stable. Considering the flue gas diversion and flue gas pressure loss, it is suggested that the number of inner diversions should be 24.

Key words: desulfurization wastewater, spray evaporation, hot air distributor, deflector, flow field

摘要：

针对脱硫废水旋转喷雾蒸发过程，建立了气液两相流动及传热传质模型，并利用该模型对某电厂300MW机组的脱硫废水蒸发过程进行了模拟，研究了热风分布器中导流板的角度和数量对干燥塔内流场、废水雾滴运动与蒸发的影响。结果表明：外导流板角度对喷雾干燥塔内流场影响比内导流板大，随着外导流板角度的增加，热烟气进入喷雾干燥塔的旋转作用更加明显，外导流板角度为32°时烟气旋流作用最好；随着内导流板角度的增加，液滴轴向运动最远距离减少，同时内导流板角度的改变对喷雾干燥塔内液滴完全蒸发时间的影响大于外导流板，内导流板角度为0°时液滴蒸发时间最短；内导流板数量对喷雾干燥塔内流场、液滴的运动和蒸发影响较小，随着内导流板数量的增加，干燥塔内流场、液滴运动距离和完全蒸发时间趋于稳定，综合考虑烟气导流与风压损失，建议内导流板数量取为24片。

关键词: 脱硫废水, 喷雾蒸发, 热风分布器, 导流板, 流场

CLC Number:

Fei LI, Haijie CHEN, Zongkang SUN, Xiaobing GU, Yuyong BAI, Fei GAO, Linjun YANG. Numerical evaporation characteristics of desulfurization wastewater by rotating spray with different hot air distributor structure[J]. Chemical Industry and Engineering Progress, 2020, 39(S2): 385-392.

李飞, 陈海杰, 孙宗康, 谷小兵, 白玉勇, 高飞, 杨林军. 热风分布器结构对脱硫废水旋转喷雾蒸发特性影响的数值模拟[J]. 化工进展, 2020, 39(S2): 385-392.

Figures/Tables 12

References 17

1	朱法华. 燃煤电厂烟气污染物超低排放技术路线的选择[J]. 中国电力, 2017, 50(3): 11-16.
	ZHU Fahua. Selection of ultra-low emission technology routes for flue gas pollutants from coal-fired power plants[J]. China Electric Power, 2017, 50(3): 11-16.
2	宋佩珊, 梁龙妮, 吴锦泽. 广东省燃煤机组超低排放改造成本收益分析[J]. 中国电力, 2017, 50(3): 55-59.
	SONG Peishan, LIANG Longni, WU Jinze. Cost-benefit analysis of ultra-low emission retrofit of coal-fired units in Guangdong Province[J]. China Electric Power, 2017, 50(3): 55-59.
3	叶春松, 黄建伟, 刘通, 等. 燃煤电厂烟气脱硫废水处理方法与技术进展[J]. 环境工程, 2017, 35(11): 10-13.
	YE Chunsong, HUANG Jianwei, LIU Tong, et al. Technology progresses and treatment methods of flue gas desulfurization wastewater in coal-fired plants[J]. Enviromental Engineering, 2017, 35(11): 10-13.
4	马双忱, 于伟静, 贾绍广, 等. 燃煤电厂脱硫废水处理技术研究与应用进展[J]. 化工进展, 2016, 35(1): 255-262.
	MA Shuangchen, YU Weijing, JIA Shaoguang, et al. Research and application progresses of flue gas desulfurization (FGD) wastewater treatment technologies in coal-fired plants[J]. Chemical Industry and Engineering Progress, 2016, 35(1): 255-262.
5	王晓焙, 杨林军．基于Fluent对脱硫废水喷雾干燥技术的研究[J]. 工业控制计算机，2019, 32(4): 94-97.
	WANG Xiaobao, YANG Linjun. Spray drying technology of desulfurization wastewater based on Fluent[J]. Industrial Control Computor, 2019, 32(4): 94-97.
6	翁卫国, 孙建国, 李钦武, 等. 脱硫废水零排放系统关键参数数值模拟研究[J]. 中国电力, 2018, 51(6): 42-47.
	WENG Weiguo, SUN Jianguo, LI Qinwu, et al. Numerical simulation research on key parameters of desulfurization wastewater zero discharge system[J]. China Power, 2018, 51(6): 42-47.
7	杨树俊, 魏玉聪, MENG Wai Woo, 等. 入口旋流对均一粒径液滴喷雾干燥塔影响的数值模拟[J]. 化工学报, 2018, 69(9): 3814-3824.
	YANG Shujun, WEI Yucong, MENG Wai Woo, et al. Numerical simulation of mono-disperse droplet spray dryer under influence of swirling flow[J]. CIESC Journal, 2018, 69(9): 3814-3824.
8	胡洪, 黄虎, 宋倩倩, 等. 喷雾干燥用旋风分离器内部流动与分离特性数值模拟[J]. 南京师范大学学报, 2010, 10(2): 3814–3824.
	HU Hong, HUANG Hu, SONG Qianqian, et al. Numerical study on flow field and separative efficiency of cyclone separator applicable to spray drying, 2010, 10(2): 3814-3824.
9	杜孟伊, 冉景煜, 张力, 等. 喷雾干燥脱硫塔内烟气流动及浆滴蒸发特性数值模拟[J]. 三峡环境与生态, 2008, 1(1): 41-46.
	DU Mengyi, RAN Jingyu, ZHANG Li, et al. Numerical simulation on the characteristics of flue gas flow and slurry drops evaporation in spray drying thionizer[J]. Environment and Ecology in the Three Gorges, 2008, 1(1): 41-46.
10	王晓焙, 耿宣, 罗天翔, 等．330MW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.
	WANG Xiaobao, GENG Xuan, LUO Tianxiang, et al. Numerical simulation and application demonstration of bypass flue spray drying technology for desulfurization wastewater of a 330MW unit[J]. Thermal Power Generation, 2019, 48(6): 96-101.
11	LAUNDER B E, SPLDING D B. Lectures in mathematical models of turbulence[M]. London: Academic Press, 1972.
12	RANZ W E, MARSHALL W R. Evaporation from drops[J]. Chemical Engineering Progress, 1952, 48(3): 141-146.
13	KUO K K. Principles of combustion [M]. New Jersey & Sons, 2005.
14	AGGRWAL S, SHU Z. Multicomponent fuel effects on the vaporization of a surrogate single-component fuel droplet[C]//AIAA Aerospace Science Meeting and Exhibit, Reno, America, 1997:12-15.
15	刘殿宇. 蜗壳式热风分布器的设计及注意事项[J]. 中国奶牛, 2014(7): 56-58.
	LIU Dianyu. Design and precautions of volute hot air distributor[J]. China Dairy Cow, 2014(7): 56-58.
16	王宗濂, 韩磊, 唐金鑫. 喷雾干燥热风分布器的设计原则[J]. 干燥技术与设备, 2003(1): 40-41.
	WANG Zonglian, HAN Lei, TANG Jinxin. Design principles of spray drying hot air distributor[J]. Drying Technology and Equipment, 2003(1): 40-41.
17	马力, 仇性启, 郑志伟, 等. 高温气流中液滴蒸发影响因素的数值研究[J]. 石油化工, 2013, 42(8): 886-890.
	MA Li, QIU Xingqi, ZHENG Zhiwei, et al. Numerical research on influencing factors of droplet evaporation in high temperature airflow[J]. Petrochemical Technology, 2013, 42(8): 886-890.

参数	内容
气相
烟气速度/m·s^-1	13
烟气温度/K	628
烟气入口条件	速度入口
烟气出口条件	压力出口
壁面条件	标准壁面函数
喷嘴流量/kg·s^-1	1.6
液相
液滴出口速度/m·s^-1	150
液滴碰壁条件	反射
液滴粒径/μm	50

参数	内容
气相
烟气速度/m·s^-1	13
烟气温度/K	628
烟气入口条件	速度入口
烟气出口条件	压力出口
壁面条件	标准壁面函数
喷嘴流量/kg·s^-1	1.6
液相
液滴出口速度/m·s^-1	150
液滴碰壁条件	反射
液滴粒径/μm	50

[1]	XU Pei, JIA Xuan, WANG Yong, QI Xuejiao, ZHAO Yujiao, LI Mingxiao. Effect of flow field on the CO₂reduction performance and products of MEC biocathode [J]. Chemical Industry and Engineering Progress, 2022, 41(7): 3816-3823.
[2]	YIN Honghe, SHEN Shaochuan, QI Liang, YAO Kejian. Hydrodynamic performances of a novel multiple downcomer tray and related CFD analysis [J]. Chemical Industry and Engineering Progress, 2022, 41(2): 601-608.
[3]	CHEN Long, LI Xiaxia, LI Weixiang, QI Ri, DENG Xin, WU Binxin. Research progress in computational fluid dynamics simulation of melt-blown fabric production [J]. Chemical Industry and Engineering Progress, 2022, 41(2): 537-553.
[4]	LI Zhenghan, TU Zhengkai. Research progress of simulation models of proton exchange membrane fuel cell [J]. Chemical Industry and Engineering Progress, 2022, 41(10): 5272-5296.
[5]	ZHANG Yuekan, GE Jiangbo, LIU Peikun, YANG Xinghua. Flow field characteristics and separation performance of multi-inlet hydrocyclone [J]. Chemical Industry and Engineering Progress, 2022, 41(1): 86-94.
[6]	GU Liyan, DONG Weigang, LIU Fengjun, CAI Chenjian, CHEN Heng, YANG Linjun. Progress on migration and transformation characteristics of volatile components in hot flue gas evaporation of desulfurization wastewater [J]. Chemical Industry and Engineering Progress, 2021, 40(S1): 434-438.
[7]	LUO Laiming, CHEN Si’an, WANG Haining, ZHANG Jin, LU Shanfu, XIANG Yan. Simulation and optimization of large-scale (200cm²) multiple-serpentine flow field for high temperature polymer electrolyte membrane fuel cells [J]. Chemical Industry and Engineering Progress, 2021, 40(9): 4975-4985.
[8]	ZHAO Ning, FENG Yongxin, LIN Tingkun, XIE Zhiwen. Research progresses on evaporation characteristics of desulfurization wastewater droplets in high-temperature flue gas [J]. Chemical Industry and Engineering Progress, 2021, 40(8): 4508-4514.
[9]	WANG Yan, CAO Zhikang, WANG Yingyao, HU Qiong, HU Peng, XIAO Yexiang. Validation of flow regime prediction model and differences of velocity component selection for rotating flow field [J]. Chemical Industry and Engineering Progress, 2021, 40(5): 2389-2400.
[10]	XIAO Guozhen, ZHONG Zhaoping, JIANG Chao, HAN Lei, MA Tianting, ZHANG Shan, JIN Baosheng. Effect of chlorine addition on mercury precipitation during coal combustion [J]. Chemical Industry and Engineering Progress, 2021, 40(12): 6557-6563.
[11]	ZHANG Jianwei, GAO Weifeng, FENG Ying, ZHANG Yifan, DONG Xin. Research progress of vortex characteristics of impinging stream reactor [J]. Chemical Industry and Engineering Progress, 2021, 40(11): 5883-5893.
[12]	Peng LI,Xiaoguang LI,Fengling YANG,Zhaoqiang LIU,Ruiqiang QI,Kai MAN. Effect of shape on performance of single-acting vacuum pump [J]. Chemical Industry and Engineering Progress, 2020, 39(3): 864-871.
[13]	WANG Xingjun, ZHOU Yongchun, AN Dexin, WU Wei, LIU Yazheng, LIN Chenyu, MA Shuangchen. Experimental study and mechanism analysis of softening and magnesium recovery of high magnesium desulfurization wastewater [J]. Chemical Industry and Engineering Progress, 2019, 38(s1): 252-258.
[14]	Shuangchen MA,Jianing CHEN,Zhongcheng WAN,Yajun XIANG,Jingrui ZHANG,Baozhong QU. Research status and development on solidification for high-salt desulfurization wastewater with cement [J]. Chemical Industry and Engineering Progress, 2019, 38(9): 4275-4283.
[15]	Shunzuo QIU,Guorong WANG,Guangshen WANG,Lin ZHONG,Xuefeng LI,Teng WANG. The analysis of flow filed and performance of spiral separator for natural gas hydrate purification [J]. Chemical Industry and Engineering Progress, 2019, 38(11): 4856-4864.