双进双出钢球磨煤机制粉系统煤粉流量软测量

Soft-sensing of pulverized coal mass flow rate in a double-input and double-output ball mill pulverizing system

为满足协调控制系统对煤粉流量测量准确可靠性的要求,本文提出了一种煤粉流量软测量方法,该方法根据影响煤粉流量各信号的特点,在低给煤量时采用卡尔曼滤波器对容量风挡板开度和磨煤机入口风压进行融合,高给煤量时采用小波滤波器对容量风量和磨煤机出口风粉混合物流速进行融合,得到容量风量融合信号后,进一步利用磨煤机煤位信号和容量风量信号修正一次风煤比,以减小非线性误差。现场应用结果表明,多源信息融合得到的软测量信号具有线性误差小、干扰成分少、可靠性高的优点。

To meet the demands of accuracy and reliability of the measurement of pulverized coal mass flow rate for the coordinated system, a method of soft-sensing for pulverized coal mass flow rate was proposed. According to the characteristics of each signal that can affect the pulverized coal mass flow rate, the Kalman filter was used to fuse the valve opening and the inlet air pressure at low coal feed rate and the wavelet filter was applied to fuse the capacity air quantity and the flow velocity of outlet gas-solid mixture at high coal feed rate. Then, the fusion signal of capacity air quantity can be obtained. Furthermore, to reduce the nonlinear error, the ratio of primary air to coal was corrected by employing the signal of coal level and capacity air quantity. The results show that, the soft-sensing signal based on multi-source information fusion has the advantages of small linear error, less high-frequency interference and high reliability.