基于气体的超声流量计精确检测技术研究

Research on accurate detection technology of ultrasonic flowmeter based on gas

针对目前市场上的部分超声波气体流量计,在检测管道内流动气体瞬时流量存在的低流速或小流量测量精度不高、计量不准确等缺陷问题,采用了一种基于卡尔曼滤波对多通道气体超声流量计测量结果进行融合的理论方法,充分合理利用多个声道的流量信息,有效判断正常值并剔除非正常数值;利用流体模拟软件Fluent对设计的多声道气体超声波流量计在融合过程中进行了声道权重系数、流场修正系数、声道方案优化、流动特性分析和计算;取得了多通道气体流量计测量数据结果稳定输出及数据精准、根据计算结果的统计规律自动调整测量结果权重等研究成果;提高了气体超声波流量计的测量精准性,得出了利用超声波对超声探头进行激励,依次对比不同条件下的超声接收信号波形和静态测量数据,将融合后的结果乘以流场修正系数为最终输出流量结果的结论;对解决超声波气体流量计精准检测计量关键技术,打破国外少数厂家技术垄断及填补在气体超声波流量计方面的技术装备空白具有重要意义。

Aiming at some ultrasonic gas flowmeters used in the market at present,there are certain defects in accurately detecting the instantaneous working condition and the standard flow rate of gas in the pipeline,a theoretical method based on Kalman filter was adopted to fuse the measurement results of multi-channel gas ultrasonic flowmeter,and the flow information of multiple sound channels was fully and reasonably utilized.The normal value was judged effectively and the abnormal value was eliminated.By using fluid simulation software Fluent,various kinds of multi-channel gas ultrasonic flowmeters were studied in the fusion process,such as channel weight coefficient and flow field correction coefficient,channel scheme optimization,flow characteristics analysis and calculation,etc.Research achievements such as stable output and accurate data of multi-channel gas flowmeter measurement results,automatic adjustment of the weight of each channel measurement results according to the statistical law of the calculation results of each channel,improved the accuracy of gas ultrasonic flowmeter during measurement,and obtained the use of ultrasonic excitation of ultrasonic probes.Compare the ultrasound received signal waveforms and static measurement data under different conditions in sequence,and multiply the fused results by the flow field correction coefficient to obtain the final output flow rate result.It was of great significance to solve the key technology of precise detection and measurement for ultrasonic gas flow meters,break the technological monopoly of a few foreign manufacturers,and fill the technical equipment gap in gas ultrasonic flow meters.