基于测量窗口气鞘多相流分析的粉尘质量浓度测量装置优化

针对煤矿粉尘质量浓度传感器测量窗口易受粉尘污染的问题,借鉴空气幕的隔尘机理,提出在光学测量窗口处增加气鞘的结构来提高粉尘质量浓度测量装置的精度。利用Fluent软件对粉尘采集通道和测量口处进行气固两相流仿真,获得管壁和测量口处粉尘质量浓度的速度云图、压力云图和粒子运动轨迹图,据此优化传感器结构。仿真及实验表明,改进后的测量口处5μm以下粒径的气流速度提高到1.8 m/s以上,使气流高速通过测量通道,有效降低了5μm以下粒径的粉尘沉积,保证了测量的准确性和时效性。

Optimization of dust concentration measurement device based on measurement window gas sheath multiphase flow analysis

To overcome the problem of the dust contamination in the measurement window of coal dust concentration sensor,based on the mechanism of dust separation by air curtain,the structure of the air sheath at the optical measurement window is put forward to improve the precision of the dust concentration measuring device.The velocity,pressure and the path of particle of the dust concentration at the pipe wall and the measurement port were obtained by simulating the gas-solid two-phase flow at the dust concentration path and the measurement port using the Fluent software,thus the structure of the sensor was optimized.Simulation and experimental results show that the velocity of air flow below 5 μm at the improved measurement port is higher than 1.8 m/s,and the high velocity of air flow through the measurement channel effectively reduces the dust deposition below 5 μm,which ensures the accuracy and timeliness of the measurement.