Control of ammonia injection in SCR denitration system based on ECDMC algorithm

After the ultra-low emission retrofit of power plant units, due to frequent changes in boiler load, many power plants tend to use excessive ammonia injection to ensure that the outlet nitrogen oxides (NOx) concentration of the selective catalytic reduction (SCR) denitration system meets the standard. However, this can lead to hazards such as ammonia escaping and blocking downstream equipment. To solve this problem, this paper proposes an energy-conservation dynamic matrix control algorithm (ECDMC) control the SCR denitration system. The manipulated variable is selected as an energy conservation indicator and added to the objective function to control the ammonia injection in the SCR system of a coal-fired power plant. Simulation results show that compared with dynamic matrix control (DMC), the ECDMC designed in this paper has the advantages of small output fluctuation, stable control, little amount of ammonia injection under different operating conditions. The method proposed in this paper provides a reference for energy conservation and environmental protection of coal-fired power plants.