Control of SCR System for NO{sub}x Reduction in a Refuse Incineration Plant Using Repetitive Control Method

摘要

The refuse incineration plant has an important role for saving the combustion energy in local heating system. But harmful combustion gas (NO{sub}x etc.) leads to some serious environmental problem. To reduce the gas, a SCR (Selective Catalytic Reduction) system is installed and it is controlled by adjusting the flow of ammonia gas (NH{sub}3). In this paper, we apply a repetitive control method to reduce NO{sub}x by adjusting the flow of ammonia gas for SCR system in a refuse incineration plant which is located in Haeundae, Pusan. Firstly, we analyze the inlet NO{sub}x period by FFT method, and verify its periodic variations. Secondly, we design a repetitive control system by using state space model method. Lastly, the effectiveness of repetitive control system is shown by comparing to a conventional PID control in simulation and experimental results.