Optimization And Integration Of SCR Control System

As the environment condition in China becomes increasingly serious, the Chinese government pays more and more attention to flue gas pollutants from coal power plant. Nitrogen oxide (NOx) is one of the main pollutants in flue gas, so more strict policies are made to limit NOx emission.As the main technique of flue gas denitration, SCR technology has many advantages, such as higher NOX reduction efficiency and lower NH3escape. So, SCR technology becomes a good choice for power plants.Most power plants have been using PID controller in the SCR control system, but the long time-delayed and non-linear characteristics of SCR control object leads to bad control effects in practice.To solve the problems of long time-delayed, great inertia of SCR (selective catalytic reduction) control object in coal power plant, a new control policy based on model predictive control was proposed.Firstly,this paper uses pre-treated experimental data from a power plant to identify process model by area method,then designs MPC controller and do the simulation experiment,lastly,discuss the application of soft measurement of NH3escape and Multiple Targets Control in SCR control system.The simulation result shows that MPC can improve dynamic characteristics and anti-interference capability of the system,and improve control quality of NOx, decrease the NH3usage. Application of soft measurement of NH3escape and multiple targets control in this article not only improve the control quality of SCR control system but also provide more control ideas.