Study on Parameter Optimization of Desulfurized Wet Flue Gas in Spray Condensation Process

doi:10.12096/j.2096-4528.pgt.21064

Abstract

Abstract:

The wide application of wet desulfurization technology makes the desulfurization efficiency reach more than 90%, but the high moisture content of flue gas after desulfurization increases the possibility of smog formation. The spray tower was the main body of research, and the three-dimensional steady-state numerical simulation of gas-liquid two-phase flow field in the tower was carried out based on Fluent software. The results show that the spray droplet diameter plays a key role in flue gas condensation and dehumidification. The smaller the droplet diameter, the larger the gas-liquid two-phase contact area, the more obvious the heat transfer effect. If the droplet diameter is less than 700 μm, the flue gas temperature drop above 6 K can be achieved. When the inlet flue gas temperature is in the range of 319-335 K, the ratio of condensed water caused by this temperature is basically unchanged. The spray droplet velocity has an integration effect on the flue gas flow field. Choosing the appropriate droplet velocity can reduce the flue gas reflux area, and improve the space utilization rate in the tower. When the droplet velocity increases to 40 m/s, the temperature drop of outlet flue gas can increase by about 1.9 K.

Key words: wet flue gas desulfurization, spray tower, gas-liquid two-phase flow, dehumidification, three-dimensional steady state numerical simulation

CLC Number:

TK 172

Wenbin LIU, Lulu LI, Xiaojin LI, Xuan YAO, Hairui YANG. Study on Parameter Optimization of Desulfurized Wet Flue Gas in Spray Condensation Process[J]. Power Generation Technology, 2023, 44(1): 107-114.

Figures/Tables 10

Tab. 1 Experimental parameters

参数	数值
塔径/m	0.5
塔高/m	5.4
填料高度/m	0.6
喷嘴张角/(°)	30
液气比/(L⋅m^-3)	2
喷淋层间距/m	1
入口烟气量/(m³⋅h^-1)	7 500
入口烟气温度/K	323
喷淋液滴温度/K	303
喷淋液滴速度/(m⋅s^-1)	21

Fig. 1 Simplified model of spray tower

Fig. 2 Nozzle arrangement

Fig. 3 Influence of droplet diameter on outlet flue gas temperature

Fig. 4 Influence of droplet size on temperature field of outlet flue gas section

Tab. 2 Saturated water vapor content at different flue gas temperatures

烟气温度/K	饱和水蒸气含量/(mg/g)
309	37.48
310	39.63
311	41.20
312	44.29
313	46.78
314	49.42
315	52.17
316	55.07
317	58.08
318	61.30
319	64.65
320	68.16
321	71.84
322	74.86
323	79.96

Fig. 5 Outlet flue gas temperature corresponding to different inlet flue gas temperatures

Fig. 6 Analysis of condensed water under different liquid-gas ratios

Fig. 7 Influence of droplet velocity on outlet flue gas temperature

Fig. 8 Influence of droplet velocity on flue gas flow field distribution

References 18

1	王润生，孔伟，杨志国，等．湿法脱硫净烟气相变凝聚促进SO₃酸雾脱除技术研究综述[J]．浙江电力，2022，41(6)：92-96．
	WANG R S， KONG W， YANG Z G，et al ．A research review of SO₃ acid mist removal from net flue gas promoted by phase change condensation technology of wet desulfurization[J]．Zhejiang Electric Power，2022，41(6)：92-96．
2	庄卓楷，严竞天，孙承朗，等．35 t/h燃煤锅炉烟气喷淋降温的数值模拟[J]．环境科学与技术，2019，42(S2)：152-157．
	ZHUANG Z K， YAN J T， SUN C L，et al ．Numerical simulation of spraying cooling on a 35 t/h coal fired boiler[J]．Environmental Science & Technology，2019，42(S2)：152-157．
3	冷亚娟，胡蕊，崔琳，等．湿法烟气脱硫塔能效特性研究[J]．发电技术，2020，41(5)：543-551． doi:10.12096/j.2096-4528.pgt.20076
	LENG Y J， HU R， CUI L，et al ．Study on energy efficiency characteristics of wet flue gas desulfurization tower[J]．Power Generation Technology，2020，41(5)：543-551． doi:10.12096/j.2096-4528.pgt.20076
4	刘志坦，惠润堂，杨爱勇，等．燃煤电厂湿烟羽成因及对策研究[J]．环境与发展，2017，29(10)：43-46．
	LIU Z T， HUI R T， YANG A Y，et al ．Research on causes and countermeasures of the wet plume in coal-fired power plant[J]．Environmental and Development，2017，29(10)：43-46．
5	王贵彦，黄素华．湿法脱硫燃煤机组“白色烟羽”节能治理[J]．华电技术，2016，38(11)：64-65．
	WANG G Y， HUANG S H ．Energy-saving treatment of “white smoke plume” of wet desulfurization coal-fired units[J]．Huadian Technology，2016，38(11)：64-65．
6	李璐璐，姚宣，张缦，等．脱硫湿烟气喷淋冷凝过程数值模拟研究[J]．洁净煤技术，2020，26(3)：82-89．
	LI L L， YAO X， ZHANG M，et al ．Numerical simulation of spray condensation process of wet flue gas[J]．Clean Coal Technology，2020，26(3)：82-89．
7	程永新，曹佩．湿法烟气脱硫系统中“石膏雨”问题的分析及对策[J]．电力建设，2010，31(11)：94-97．
	CHENG Y X， CAO P ．Analysis on and solution to the “gypsum rain” problem of wet flue gas desulfurization system[J]．Electric Power Construction，2010，31(11)：94-97．
8	田路泞，韩哲楠，董勇，等．燃煤电厂湿烟气余热及水分回收技术研究[J]．洁净煤技术，2017，23(5)：105-110．
	TIAN L N， HAN Z N， DONG Y，et al ．Review of water recovering technologies from flue gas in coal fired power plant[J]．Clean Coal Technology，2017，23(5)：105-110．
9	苏鹏．烟羽综合治理及冷却喷淋装置数值模拟优化研究[D]．北京：中国矿业大学，2019． doi:10.36909/jer.v7i4.7085
	SU P ．Comprehensive treatment of flue gas and optimization of cooling spraying device research on numerical simulation[D]．Beijing：China University of Mining and Technology，2019． doi:10.36909/jer.v7i4.7085
10	潘春锋．湿法脱硫烟气粉尘特性分析及脱除方法探讨[J]．中国水运，2016，16(4)：116-118．
	PAN C F ．Analysis of flue gas dust characteristics in wet desulfurization and discussion of removal methods[J]．China Water Transport，2016，16(4)：116-118．
11	李晨朗，冀秉强，宋蔷，等．湿法脱硫喷淋除尘过程的数值模拟[J]．中国电机工程学报，2019，39(4)：1070-1079．
	LI C L， JI B Q， SONG Q，et al ．Numerical simulation of synergetic removal of particulate matter by spraying during wet flue gas desulfurization[J]．Proceedings of the CSEE，2019，39(4)：1070-1079．
12	刘润哲．细颗粒在蒸汽异相凝结过程中核化长大特性研究[D]．上海：华东理工大学，2019．
	LIU R Z ．The nucleation and growth characteristics of fine particles in the process of vapor heterogeneous condensation[D]．Shanghai：East China University of Science and Technology，2019．
13	许浩洁．湿法除尘过程多相流数值模拟与实验研究[D]．南京：江苏大学，2019．
	XU H J ．Numerical simulation and experimental study on the multiphase flow of wet dusting process[D]．Nangjing：Jiangsu University，2019．
14	查小波．空气与水直接接触式热回收装置性能分析及优化研究[D]．南京：东南大学，2018．
	CHA X B ．Performance analysis and optimization of air-water direct contact heat recovery device[D]．Nangjing：Southeast University，2018．
15	薄佳燕，卢玫．湿法脱硫喷淋塔流场均匀性数值模拟研究[J]．能源工程，2018(2)：47-51．
	BO J Y， LU M ．Numerical simulation study on flow field uniformity of FGD spray tower[J]．Energy and Engineering，2018(2)：47-51．
16	马如，齐永锋，王妹婷，等．烟气湿法处理喷淋塔内流场的数值模拟研究[J]．工业安全与环保，2018，44(12)：58-62． doi:10.3969/j.issn.1001-425X.2018.12.016
	MA R， QI Y F， WANG M T，et al ．Numerical simulation of flow field in wet flue gas spray tower[J]．Industrial Safety and Environmental Protection，2018，44(12)：58-62． doi:10.3969/j.issn.1001-425X.2018.12.016
17	卜奔，乔昭毓，刘付永，等．双面对切进口结构的湿法烟气脱硫喷淋塔内流场的数值模拟和实验研究[J]．科学技术与工程，2018，18(16)：323-328． doi:10.3969/j.issn.1671-1815.2018.16.052
	BU B， QIAO Z Y， LIU F Y，et al ．Numerical simulation and experimental study on the flow field in wet flue gas desulfurization spray tower with two side cut inlet structure[J]．Science Technology and Engineering，2018，18(16)：323-328． doi:10.3969/j.issn.1671-1815.2018.16.052
18	杨丁，叶兴联，郭俊，等．湿法烟气脱硫流场优化数值模拟与模型试验研究[J]．电力科技与环保，2018，34(2)：9-13． doi:10.3969/j.issn.1674-8069.2018.02.003
	YANG D， YE X L， GUO J，et al ．Numerical simulation and model experimental research on optimizing the flow field in wet flue gas desulfurization[J]．Electric Power Technology and Environmental Protection，2018，34(2)：9-13． doi:10.3969/j.issn.1674-8069.2018.02.003

[1]	Yue ZHU,Yonglong YANG. Influence Analysis on Haze Control of Ultra-low Emission Wet Flue Gas Desulfurization of Coal-fired Power Plants [J]. Power Generation Technology, 2020, 41(3): 295-300.
[2]	Haiwei YAN,Yazhao WANG,Jingdong GUO,Ke WANG,Dongmei LIAO. Cause Analysis and Control Countermeasures of Slurry Overflow in Desulfurization Absorber Tower Wastewater Pit [J]. Power Generation Technology, 2019, 40(2): 141-147.
[3]	XIAO Jing. Design of Heat Pump Solution Desiccant Air Conditioning System [J]. Power Generation Technology, 2017, 38(1): 74-77.