Analysis on Operating Status of SCR Facilities in Active Coal-Fired Units

doi:10.11930/j.issn.1004-9649.2017.04.157.05

Abstract

Abstract: In order to provide helpful reference for flue gas ultra-low emission retrofits, current operating status of the SCR flue gas denitration system are analyzed which have been installed on 61 generation units in 26 power plants. A variety of practical data are obtained including the denitration efficiency, inlet and outlet NO_x concentrations, ammonia molar ratio, SO₂/SO₃ conversion rate, ammonia escape rate, running flue gas temperature, system resistance, temperature drop, etc. Also the major functionalities of the SCR denitration system are acknowledged. From the study results the overall performance is satisfactory for most of the denitration systems. However there still exist some problems as follows. The SCR system inlet NO_x concentration deviates significantly from the original designed value due to the factors such as the furnace type, coal quality, combustion condition and design margin. The improper ammonia injection causes higher-than-normal ammonia molar ratio and consequentially the ammonia escape concentration exceeding the related standard. Low SCR system inlet flue gas temperature at low loadings and large system temperature drops are also noticed in some units. Therefore, suggestions and advice are put forward accordingly.

Key words: coal-fired plant, flue gas denitration, SCR denitration device, denitration efficiency, escaping ammonia

CLC Number:

TM621

FENG Qianwei, ZHANG Yang, WANG Fengji, ZHU Yue. Analysis on Operating Status of SCR Facilities in Active Coal-Fired Units[J]. Electric Power, 2017, 50(4): 157-161.

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URL: https://www.electricpower.com.cn/EN/10.11930/j.issn.1004-9649.2017.04.157.05

https://www.electricpower.com.cn/EN/Y2017/V50/I4/157

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