中速磨煤机进口一次风量测量装置的选型及控制方式

Selection and control method about measuring device of primary air quantity for medium-speed pulverizer

中速磨煤机一次风混合风道内的风量测量装置布置比较紧凑,易造成风道内的速度场和温度场不均匀,较难实现风量的准确测量。对机翼式、双文丘里式、威力巴式、多点等截面式、孔板型、热扩散式这6种一次风量测量装置进行比较,结果表明多点等截面式一次风量测量装置为其中最佳方式。对于多点等截面式一次风量测量装置,差压和温度信号分两种控制方式接入,即各截面差压和温度数值分别取值计算再计总和,和将各差压和温度值先混合平均再用平均值进行计算总风量,经过比较后结果表明方式二较方式一更具可行性。

Velocity field and temperature field in primary air duct for medium-speed pulverizer are inhomogeneous because of arrangement of air quantity measuring device, which air quantity is hard to accurately measure. Air quantity measuring device of wing type, double venturi type, verabar type, multi point section, kong ban and thermal diffusion type were relatively compared. The comparison results showed that air quantity measuring device of multi point section was the best choice. There were two control methods for signal of differential pressure and temperature, one was that each section of differential pressure and temperature were respectively calculated thus summed, the other was that differential pressure and temperature were mixed mean thus total air volume was calculated. The second kind was more feasible than the first one after mutual comparison.