Study on Removal and Distribution Mechanism of Ammonia in Flue Gas of Coal-fired Power Plant

doi:10.12096/j.2096-4528.pgt.21127

Abstract

Abstract:

The removal efficiency of ammonia in denitrification downstream equipment, concentration and distribution mechanism of ammonia in fly ash and slurry were studied under the condition of high concentration of ammonia escaping from denitrification by selective catalytic reduction (SCR) in coal-fired power plants. Through sampling analysis of 350 MW and 600 MW units, the results show that: the escaping ammonia removal efficiencies of air preheater, electrostatic precipitator and wet desulphurization system are 3.37%-6.63%, 75.14%-83.28% and 36.36%-46.38%, respectively. The ammonia removal efficiencies of these downstream environmental protection equipment are high, and the ammonia concentration at chimney entrance decreases obviously compared with that at denitrification outlet. The ammonia content in fly ash is inversely proportional to the particle size of fly ash. Ammonia concentration in desulfurized flue gas increases with the increase of ammonia concentration in original flue gas. The removal efficiency of ammonia in desulphurization system decreases with the increase of slurry pH value. The results have great significance to the units’ environmental protection and economic running.

Key words: coal-fired power plant, selective catalytic reduction (SCR), ammonia slip

CLC Number:

TK 09

Pan JI. Study on Removal and Distribution Mechanism of Ammonia in Flue Gas of Coal-fired Power Plant[J]. Power Generation Technology, 2023, 44(3): 392-398.

Figures/Tables 10

References 28

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参数	1号机组	2号机组
灰分质量分数A_ar/%	27.37	24.53
挥发分质量分数V_ad/%	12.28	12.80
硫分质量分数S_{t， ad}/%	1.68	1.72
低位发热量Q_{net， ar}/(MJ/kg)	20.21	20.77

参数	1号机组	2号机组
灰分质量分数A_ar/%	27.37	24.53
挥发分质量分数V_ad/%	12.28	12.80
硫分质量分数S_{t， ad}/%	1.68	1.72
低位发热量Q_{net， ar}/(MJ/kg)	20.21	20.77

机组编号	负荷/MW	SCR入口NO _x 质量浓度/(mg/m³)	SCR出口NO _x 质量浓度/(mg/m³)
1	300	632	12
1	300	617	36
2	550	696	11
2	550	688	41

机组编号	负荷/MW	SCR入口NO _x 质量浓度/(mg/m³)	SCR出口NO _x 质量浓度/(mg/m³)
1	300	632	12
1	300	617	36
2	550	696	11
2	550	688	41

机组编号	工况	采样点位置
机组编号	工况	SCR出口	APH出口	ESP出口	WESP出口
1	1	17.83	17.23	2.88	1.72
1	2	7.91	7.59	1.65	1.05
2	1	16.44	15.41	3.04	1.63
2	2	5.73	5.35	1.33	0.75