Design and operation of the low-temperature flue gas evaporation-main flue duct drying system for desulfurization wastewater treatment in coal-fired power plants

doi:10.3969/j.issn.1674-1951.2021.12.005

Abstract

Abstract:

Evaporating and drying desulfurization wastewater by waste heat from low-temperature flue gas can realize zero liquid discharge of desulfurization wastewater, which is of advantages of simple structure, low investment and operation cost, and little maintenance work. The operation performance of a low-temperature flue gas evaporation-main flue duct drying system depends on wastewater characteristics, unit load, flue gas temperature, flue gas flow field and other factors,which should be optimized according to the actual operation condition. The low-temperature flue gas evaporation-main flue duct drying system of a 300 MW coal-fired unit was optimized according to its flue gas parameters and wastewater characteristics. The performance test results show that the flue gas evaporation and condensation system can process 10.44 m³/h wastewater; the concentrated water flow is 0.96 m³/h on average; and the main flue duct evaporation system can process 1.56 m³/h wastewater on average. The relative operation parameters meet the design requirement of the system.

Key words: thermal power plant, zero discharge, desulfurization wastewater, low-temperature flue gas, main flue duct, evaporative concentration, evaporative drying

CLC Number:

X703.1

JIN Yinjia, ZHENG Changle, WANG Qunkui, SONG Da. Design and operation of the low-temperature flue gas evaporation-main flue duct drying system for desulfurization wastewater treatment in coal-fired power plants[J]. Huadian Technology, 2021, 43(12): 29-35.

Figures/Tables 7

Tab.1

Tab.2

Fig.1

Tab.3

Tab.4

Tab.5

Tab.6

References 28

[1]	山东省环境保护局, 山东省质量技术监督局. 山东省半岛流域水污染综合排放标准:DB 37/676—2007[S].
[2]	晋银佳, 孙海峰, 王丰吉, 等. 燃煤电厂高盐废水“零排放”处理工艺及技术经济分析[J]. 华电技术, 2017, 39(12):46-49.
	JIN Yinjia, SUN Haifeng, WANG Fengji, et al. A case study of economic comparison between different treatment technologies of high salinity wastewater in coal-fired power plant[J]. Huadian Technology, 2017, 39(12):46-49.
[3]	连坤宙, 陈景硕, 刘朝霞, 等. 火电厂脱硫废水微滤、反渗透膜法深度处理试验研究[J]. 中国电力, 2016, 49(2):148-152.
	LIAN Kunzhou, CHEN Jingshuo, LIU Zhaoxia, et al. Experimental study on the reduction treatment of desulfurization wastewater in power plants by membrane[J]. Electric Power, 2016, 49(2):148-152.
[4]	王海, 张峰榛, 王成端, 等. MVR技术处理高盐废水工艺的模拟与分析[J]. 环境工程, 2015, 33(10):35-37.
	WANG Hai, ZHANG Fengzhen, WANG Chengduan, et al. Simulation and analysis of MVR technology in the treatment of hypersaline wastewater[J]. Environmental Engineering, 2015, 33(10):35-37.
[5]	毛彦霞. 蒸汽机械再压缩技术处理含盐废水试验研究[D]. 重庆:重庆交通大学, 2014.
[6]	钱感, 关洪银. 燃煤电厂脱硫废水综合处理工艺[J]. 水处理技术, 2017, 43(2):136-138.
	QIAN Gan, GUAN Hongyin. Treatment technology of desulfurization wastewater in coal-fired power plant[J]. Technology of Water Treatment, 2017, 43(2):136-138.
[7]	杨跃伞, 苑志华, 张净瑞, 等. 燃煤电厂脱硫废水零排放技术研究进展[J]. 水处理技术, 2017, 43(6):29-33.
	YANG Yuesan, YUAN Zhihua, ZHANG Jingrui, et al. Research progress of technologies for zero-discharge of desulfurization wastewater from coal-fired power plants[J]. Technology of Water Treatment, 2017, 43(6):29-33.
[8]	张江涛, 曹红梅, 董娟, 等. 火电厂废水零排放技术路线比较及影响因素分析[J]. 中国电力, 2017, 50(6):120-124.
	ZHANG Jiangtao, CAO Hongmei, DONG Juan, et al. Comparison on the technical routes of zero liquid discharge of fossil-fired power plants and analysis on the influencing factors[J]. Electric Power, 2017, 50(6):120-124.
[9]	陈海杰, 李飞, 孙莹, 等. 燃煤机组全厂废水零排放技术方案分析[J]. 华电技术, 2020, 42(9):88-92.
	CHEN Haijie, LI Fei, SUN Ying, et al. Study on wastewater zero discharge technical scheme for coal-fired power plants[J]. Huadian Technology, 2020, 42(9):88-92.
[10]	聂向欣, 郑宗明, 崔孝洋, 等. 燃煤电厂湿法烟气脱硫废水处理技术研究进展[J]. 中国电力, 2018, 51(12):175-179.
	NIE Xiangxin, ZHENG Zongming, CUI Xiaoyang, et al. Research progress on the treatment technologies of wet flue gas desulfurization wastewater in coal-fired power plants[J]. Electric Power, 2018, 51(12):175-179.
[11]	郑长乐, 晋银佳, 张爱军, 等. 燃煤电厂高盐废水深度浓缩处理系统设计及技术经济分析[J]. 发电技术, 2019(S1):58-63.
	ZHENG Changle, JIN Yinjia, ZHANG Aijun, et al. System design and technical economic comparison between different concentration technologies of high salinity wastewater in coal-fired power plant[J]. Power Generation Technology, 2019(S1):58-63.
[12]	侯致福, 魏晓仪, 邢树涛, 等. 300 MW机组低温余热闪蒸脱硫废水零排放技术应用研究[J]. 华电技术, 2020, 42(3):31-36.
	HOU Zhifu, WEI Xiaoyi, XING Shutao, et al. Research on low-temperature waste heat flash evaporation technology applied in desulfurization wastewater zero discharge of 300 MW units[J]. Huadian Technology, 2020, 42(3):31-36.
[13]	万忠诚. 脱硫废水低温烟气浓缩减量技术研究[J]. 云南化工, 2019, 46(10):27-28, 31.
	WAN Zhongcheng. Study on low temperature thermal concentration and reduction technology of desulfurization wastewater[J]. Yunnan Chemical Technology, 2019, 46(10):27-28, 31.
[14]	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 of key parameters of zero discharge system for WFGD wastewater[J]. Electric Power, 2018, 51(6):42-47.
[15]	姚子麟, 袁伟中, 陈彪, 等. 燃煤电厂末端废水调质与干化技术研究及其工程示范[J]. 中国电力, 2018, 51(6):48-53.
	YAO Zilin, YUAN Weizhong, CHEN Biao, et al. Technical study and demonstration project on the quality control and drying of terminal wastewater in coal-fired power plants[J]. Electric Power, 2018, 51(6):48-53.
[16]	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.
	JIN Yinjia, WANG Shuai, JI Haihong, et al. Numerical simulation of desulfurization wastewater treatment with in-depth filtration-flue evaporation process[J]. Electric Power, 2016, 49(12):174-179.
[17]	康梅强, 邓佳佳, 陈德奇, 等. 脱硫废水烟道蒸发零排放处理的可行性分析[J]. 土木建筑与环境工程, 2013, 35(6):238-240.
	KANG Meiqiang, DENG Jiajia, CHEN Deqi, et al. Analysis on the feasibility of desulfurization wastewater evaporation treatment in flue gas duct without pollution discharge[J]. Journal of Civil,Aichitectural & Environmental Engineering, 2013, 35(6):238-240.
[18]	王群奎, 晋银佳, 宋达, 等. 某300 MW燃煤机组脱硫废水旁路烟道蒸发系统设计[J]. 华电技术, 2020, 42(3):19-24.
	WANG Qunkui, JIN Yinjia, SONG Da, et al. Design of the desulfurization wastewater bypass flue evaporation system in a 300 MW coal-fired power plan[J]. Huadian Technology, 2020, 42(3):19-24.
[19]	MA S, CHAI J, CHEN G, et al. Research on desulfurization wastewater evaporation: Present and future perspectives[J]. Renewable & Sustainable Energy Reviews, 2016, 58:1143-1151.
[20]	张富峰, 刘道宽, 曲保忠, 等. 脱硫废水烟气蒸发技术中的数值模拟研究现状与发展[J]. 华电技术, 2020, 42(3):8-18.
	ZHANG Fufeng, LIU Daokuan, QU Baozhong, et al. Status and progress of numerical simulation in flue gas evaporation technology for desulfurization wastewater[J]. Huadian Technology, 2020, 42(3):8-18.
[21]	连鹏, 王凯亮. 脱硫废水烟气蒸发处理技术的分析及应用[J]. 华电技术, 2018, 40(10):59-62.
	LIAN Peng, WANG Kailiang. Analysis and application of flue gas evaporation treatment technology for desulfurization wastewater[J]. Huadian Technology, 2018, 40(10):59-62.
[22]	蔡继东, 万忠诚, 张庭怿. 燃煤电厂脱硫废水零排放工程的设计与应用[J]. 广东电力, 2018, 31(5):28-34.
	CAI Jidong, WAN Zhongcheng, ZHANG Tingyi. Design and application of desulfurization wastewater zero discharging project of coal-fired power plant[J]. Guangdong Electric Power, 2018, 31(5):28-34.
[23]	王涛, 邢浩若, 刘道宽, 等. 机械雾化蒸发脱硫废水的理论研究与实践[J]. 华电技术, 2020, 42(9):82-87.
	WANG Tao, XING Haoruo, LIU Daokua, et al. Theoretical study and practice of desulfurization wastewater vaporization by mechanical atomization[J]. Huadian Technology, 2020, 42(9):82-87.
[24]	贺继旺, 李涛, 党小建, 等. 超超临界660 MW机组烟道蒸发结晶脱硫废水零排放技术[J]. 热力发电, 2019, 48(1):110-114.
	HE Jiwang, LI Tao, DANG Xiaojian, et al. Zero discharge technology of flue gas evaporation and crystallization desulfurization wastewater in an ultra-supercritical 660 MW unit[J]. Thermal Power Generation, 2019, 48(1):110-114.
[25]	柴晋, 万忠诚, 武凯, 等. 燃煤电厂脱硫废水烟气蒸发技术进展与应用[J]. 洁净煤技术, 2019, 25(2):25-31.
	CHAI Jin, WAN Zhongcheng, WU Kai, et al. Development and application of flue gas evaporation technology for waste water desulfurization in coal-fired power plants[J]. Clean Coal Technology, 2019, 25(2):25-31.
[26]	粉煤灰混凝土应用技术规范:GB/T 50146—2014[S]北京: 中国计划出版社, 2014.
[27]	混凝土质量控制标准:GB 50164—2011[S]北京: 中国建筑工业出版社, 2011.
[28]	固定污染源废气氯化氢的测定硝酸银容量法:HJ 548—2016[S]北京: 中国环境出版社, 2016.

项目	单位	数值
pH值		6.45
悬浮物质量浓度	mg/L	176
总溶解固体质量浓度	mg/L	31 500
氯离子质量浓度	mg/L	9 180
氟离子质量浓度	mg/L	24
硫酸根质量浓度	mg/L	13 248
钙离子质量浓度	mg/L	657
镁离子质量浓度	mg/L	824
钠离子质量浓度	mg/L	7 736
钾离子质量浓度	mg/L	118
镍离子质量浓度	mg/L	0.77
铅离子质量浓度	mg/L	0.36
汞离子质量浓度	μg/L	0.36
镉离子质量浓度	mg/L	0.34
铬酸根质量浓度	mg/L	—
砷酸根质量浓度	mg/L	—

项目	除尘器入口	引风机出口
烟气量/(m³·h^-1)	1.1×10⁶	1.1×10⁶
烟气温度/℃	138	132
HCl质量浓度/(mg·m^-3)	62.4	62.8
烟气湿度/%	6.59	6.56
粉尘质量浓度/(mg·m^-3)	27 500	25

项目		规格型号	数量
烟气系统	烟道材料以及支架	Q235B,厚度6 mm	1批
	烟道进口挡板门	2.7 m×2.7 m×0.4 m,含执行机构	1台
	烟道出口挡板门	2.6 m×2.6 m×0.4 m,含执行机构	1台
	电动葫芦	50 kN	2台
	浓缩塔增压风机	q_V=300 000 m³/h,p=1.4 kPa	1台
	密封风机	q_V=15 000 m³/h,p=0.8 kPa	1台
	密封风机电加热器		1套
废水系统	废水缓冲箱	V=80 m³,碳钢衬胶	1台
	废水箱搅拌器		1套
	废水泵	q_V=20 m³/h,h=25 m	2台
蒸发系统	蒸发浓缩器	φ5.9 m×22.0 m,包括内件	1座
	塔检修平台钢构		1批
	除雾器		1套
	浓水缓冲箱	V=10 m³,碳钢衬胶	1台
	循环泵	q_V=480 m³/h,h=23 m	4台
	浓液泵	q_V=30 m³/h,h=30 m	4台
	雾化喷嘴	2205合金钢,孔径5 mm	24个
中和系统	NaOH加药箱及搅拌器	V=1 m³,塑料	1套
	NaOH加药泵	q_V=500 L/h,h=10 m	1台
	NaOH计量泵	q_V=500 L/h,h=10 m	1台
冲洗系统	冲洗水泵	q_V=60 m³/h,h=50 m	2台

名称	规格型号	数量
输送泵	q_V =2 m³/h,h =100 m	2台
双流体雾化喷射装置	250 L/h,哈氏合金C2000	8套
伴热管线	50 W/m	500 m
空气压缩机	q_V =25 m³/min,p=0.8 MPa	1台
压缩空气罐	碳钢,φ1 m×3 m,V=2 m³,p =0.8 MPa	1个
冲洗水泵	离心泵,q_V=10 m³/h,h =60 m	2台
吹灰器及附件		4台
输灰仓泵	q_V =1 m³/h,h=20 m	2台

项目		入口烟气量/(m³·h^-1)	入/出口烟气温度/℃	烟气温降/℃	平均蒸发水量/(m³·h^-1)
低温烟气蒸发浓缩系统	80%负荷率	1.416×10⁵	132/55	77	9.48
低温烟气蒸发浓缩系统	50%负荷率	1.377×10⁵	116/52	64	5.45
主烟道蒸发系统	80%负荷率	9.967×10⁵	138/135	3	1.50
主烟道蒸发系统	50%负荷率	6.561×10⁵	119/116	3	1.10