Analysis on the Optimization Technology of Precise Ammonia Injection in SCR Denitration System

doi:10.12096/j.2096-4528.pgt.20035

Abstract

Abstract:

In order to improve the operation level of selective catalytic reduction (SCR) denitration system, through the analysis of the technical characteristics of the existing control system of SCR denitration, it was found that the delay of existing test instruments is the direct factor affecting the accuracy and real-time performance of the denitration ammonia injection control. To improve the accuracy and real-time performance of ammonia injection control, the optimization control technology of precise ammonia injection in denitration system was proposed. Moreover, the technologies of the total amount control of ammonia injection, divisional ammonia injection control and precise measurement of NO_x concentration field were organically combined to build a precise ammonia injection control strategy with total amount control, subarea ammonia injection adjustment and NO_x concentration field precise measurement feedforward as the main means. This work is benefit to reduce the operation cost of denitration system and weaken the impact of escaping ammonia, and provides the technical support for the application of the next precise ammonia injection optimization technology.

Key words: selective catalytic reduction (SCR), total amount control, precise ammonia injection, control strategy

CLC Number:

TK47

Zishang LI, Renhan ZHU, Zhen DU. Analysis on the Optimization Technology of Precise Ammonia Injection in SCR Denitration System[J]. Power Generation Technology, 2021, 42(5): 630-636.

Figures/Tables 8

Fig.1 Schematic diagram of fixed mole ratio control

Fig.2 Schematic diagram of outlet NOx setting control mode

Fig.3 Schematic diagram of total ammonia injection control

Fig.4 Schematic diagram of partition ammonia injection

Fig.5 Flow chart of sampling by zone rotation

Fig.6 Flow chart of direct insertion in-situ measurement

Fig.7 Control diagram based on inertia base

Fig.8 Control diagram based on outlet NOx feedforward

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