直流锅炉全工况动态水煤配比优化

Dynamic Water-coal Ratio Optimization of Once-throughBoiler Under All Working Conditions

超临界机组被控对象难以控制,机组输出对于给煤量和给水流量指令的响应速度不同,使现有的控制方案难以快速稳定机组输出。为了解决这个问题,在分析了超临界纯凝机组模型的基础上,首先通过水跟煤控制方案和煤跟水控制方案在阶跃扰动下的系统响应曲线的对比,得到水跟煤控制方案下,系统输出参数响应曲线的超调量和响应速度更优;但给煤量指令所控制参数的响应曲线依旧存在迟延,针对这一问题,在水跟煤控制方案中加入动态给水补偿环节。仿真结果证明,当机组负荷变化时,加入一阶给水补偿环节后的响应曲线,在稳定性和快速性上均优于加入二阶给水补偿环节,并解决了输出响应曲线中的迟延问题。

Due to the unmanageable controlled object of supercritical unit and the response speed difference of unit output to feed-coal instruction and feed-water instruction,it is difficult for the existing control scheme to stabilize the unit output quickly.Therefore,this paper analyzed the model of supercritical pure condensing unit.Firstly,through the comparison of the system response curve of the water coal control scheme and the coal water control scheme under the step disturbance,we found that,under the water coal control scheme,the overshoot and response speed of the system output parameter response curve are higher.However,there is still delay in the response curve of the parameters controlled by the feed-coal instruction.To solve this problem,we added dynamic feed water compensation to the water coal control scheme.The simulation results show that when the unit load changes,the response curves which add the first-order feed water compensation link are better than the second-order feed water compensation link in stability and rapidity,and the delay in the output response curve is eliminated.