基于预测函数控制算法的脱硝优化控制

Denitration Optimization Control Based on Predictive Function Control Algorithm

为了弥补PID(比例-积分-微分)控制的不足,应用PFC(预测函数控制)提高脱硝优化控制系统响应速度,提高催化剂出口氮氧化物浓度的控制精度,减少过量喷氨,应对复杂的环境干扰,改善系统的控制品质。根据脱硝系统的过程特点进行模型辨识,构建一组以喷氨量及催化剂出口氮氧化物浓度为输入和输出,同时考虑多重干扰及环境影响的模型;将预测函数控制算法在PLC(可编程逻辑控制器)平台上实现,考虑到过程的时滞特性,形成整体的控制方案,设计一套自动控制催化剂出口氮氧化物浓度的脱硝优化控制平台,控制氮氧化物浓度在环保目标以内;在脱硝优化平台部署后72 h内,对平台性能进行监控和分析,对影响催化剂出口氮氧化物浓度的工况进行记录,从总体效果来看,该方案应用简单,方便对模型在线调参,在抑制扰动方面具有更快的响应速度,同时具有更高的自动化水平。

To make up for the deficiency of PID(proportion-integral-differential)control,PFC(predictive functional control)is used to improve the response speed of the denitration optimization control system,improve the control accuracy of the nitrogen oxide concentration at the outlet of the catalyst,reduce excessive ammonia injection,and respond to complex environmental disturbances and improve the control quality of the system.According to the process characteristics of the denitration system,the model is identified to establish a set of models with ammonia injection and nitrogen oxide concentration at the outlet of the catalyst as inputs and outputs,while considering multiple interference and environmental impact;the predictive functional control algorithm is implemented on a programmable logic controller(PLC)platform;given the time-lagging characteristics,an overall control scheme is formulated to design a set of optimized denitration control platform that automatically controls the concentration of nitrogen oxides at the outlet of the catalyst,controlling the concentration of nitrogen oxides in environmental protection goals;within 72 hours after the deployment of the denitration optimization platform,the performance of the platform is monitored and analyzed,and the operating conditions that affect the concentration of nitrogen oxides at the outlet of the catalyst are recorded.The scheme is simple to apply and convenient for online parameter adjustment of the model,responding fast to disturbance suppression and being highly automatic.