基于双截面ECT的气/固两相流参数检测系统

Parameter measurement system for gas /solid two phase flow based on twin-plane electrical capacitance tomography

为了实现多相流的流动过程在线监测和多参数测量,设计并研发了一套应用于气/固两相流检测的双截面8电极电容层析成像系统。采用交流法电容检测原理实现具有16个独立电容检测通道的电容测量电路,实测系统的成像速度为590帧/秒。将双截面电容层析成像系统用于气/固两相流的实时检测,并将两层截面的图像作相关计算,获取成像截面的固相速度分布。由固相速度和浓度最终算出气/固两相流的固相质量流量,从而实现气/固两相流浓度、速度、流量等多参数的综合检测。将双截面ECT传感器算得的质量流量与发料罐重力传感器获取的质量流量作对比发现,两者具有较好的一致性,流量测量误差小于8%。

In order to realize the muhiphase flow process online monitoring and multi-parameter measurement, a set of twin-plane 8 electrode electrical capacitance tomography （ECT） system for gas/solid two phase flow measurement is designed and developed. Each plane has 8 measurement electrodes. The ECT hardware has 16 independent channels of AC-based capacitance measurement circuit. The ECT data acquisition speed is 590 frames per second. The twin- plane ECT imaging system was applied in the real time detection of gas/solid two phase flow. The images on the two planes were calculated in correlation, and the velocity distribution of the solid phase flow on the imaging plane was obtained. The mass flow rate of the solid phase in the gas/solid two phase flow could be finally calculated from the solid phase flow velocity and the concentration. Therefore, the multi-parameter measurement of the gas/solid two phase flow is realized, which includes the concentration, velocity and flow rate. The mass flow rate obtained from twin- plane ECT sensor is compared with the mass flow rate acquired from the gravity sensor on the feeding hopper;it is found that they are in good consistency,and the flow rate measurement error is less than 8%.