云浮发电厂烟气脱硫系统pH值自动控制回路的改进

Improvement of Automatic Control Loop of pH Value of Flue Gas Desulphurization System inYunfu Power Plant

云浮发电厂烟气脱硫系统石灰石浆液pH值自动控制回路采用单回路控制方式,存在调节迟缓大、控制不稳等问题,于是对原控制方案进行了改进。采用串级控制、抗积分饱和、速率限制等措施来提高控制稳定性和反应速率,采用超前-滞后模块代替滤波模块以提高调节灵敏度,并对pH计冲洗时造成的冲击采取了防控措施。改进后的自动控制回路投运效果良好,pH值自动控制过程平稳、及时、准确,能满足生产的要求。

Automatic control loop of pH value of limestone slurry in flue gas desulphurization system of Yunfu power plant employs single loop control mode and there exist problems like long adjustment delay,unstable control and so forth,therefore the previous control scheme is improved.Cascade control,anti-integral saturation,rate limit and what not are adopted to improve control stability and reaction rate,and lead-lag module is used to replace filter module for the purpose of sensitivity enhancement.Besides,prevention and control measures are taken to decrease shock from pH meter wash.The application of improved automatic control loop has achieved good result,automatic control process of pH value is stable,promptly and can satisfy requirements of production.