汇管出口流量分配对下游孔板流量计计量的影响研究

Study on the Effect of Manifold Outlet Flow Distribution on Downstream Orifice Flowmeter Metering

配气站中,由于汇管结构不合理且汇管出口流量差异太大,管路孔板流量计计量曲线常出现波动较大,测量值失真的现象。针对这种情况,文章使用流体仿真软件Fluent建立了标准孔板内气体三维稳定流动模型,计算了孔板稳定流动时的流出系数和孔板前后D和D/2截面上的压力差,利用压力差、流出系数得到孔板计量流量,结合实际流量和孔板计量流量对孔板进行标定;分别计算了孔板在不同流量分配比例下的计量误差。结果表明:采用CFD数值模拟可以有效获得孔板流量计内部的流场分布情况,并可根据具体的应用场合得到相应的计量流量和实际流量,从而实现对孔板流量计的标定。

Gas distribution station, due to the unreasonable structure of pipe and pipe outlet flow difference is too big, pipe orifice plate flowmeter measurement curve often fluctuate greatly, the measurement value distortion phenomenon.In view of this situation, this paper uses the fluid simulation software Fluent to establish the three-dimensional steady flow model of the gas in the standard orifice, the flow coefficient and the pressure difference on the D and D/2 cross sections of the orifice plate are calculated.Using the pressure difference, the outflow coefficient can be measured by orifice plate, and combined with the actual flow and orifice plate metering flow to calibrate the orifice plate;The measurement error of orifice plate in different flow distribution ratio was calculated. Results show： CFD numerical simulation can be used to effectively get the flow field distribution of orifice flowmeter, According to the specific application occasions, the corresponding measurement flow and actual flow rate can be obtained. So as to realize the calibration of orifice flowmeter.