质量流量计在成品油零售计量中的应用

Application of Mass Flowmeter in the Metering of Product Oil by Retail.

在成品油零售计量中,一般采用体积流量与密度测试的方法,冉经过计算求得质量。由于体积与密度测试受多种因素的影响,误差很大。若采用质量流量计则不受这些因素的影响,并可提高计量精度。介绍了石家庄炼油厂引进德国生产的E+H质量流量计的使用情况,从流量计安装、使用、量程和工作环境等方面分析了使用中出现的问题。测量传感器的最佳安装方式应为垂直式,若为水平安装,其出口段必须有1～2m的直管段,且维持20kPa的表压。通过流量计的油品如果发生汽化,将引起较大的计量误差,为此要提高流量计的背压、减少油品汽化以及减少流量计振动。

The mass of product oil at retail is generally taken from the calculations through the method of volumetric flow/density inspection. However, this method, which is prone to influences from many factors, may produce a considerable error. Only mass flowmeter can avoid the factors, and increase the metering accuracy. The paper introduces the application of E+H mass flowmeter introduced from Germany by Shiji-azhuang Oil Refinery. Problems on the application of mass flowmeter are analyzed from installation, operation, measuring range and operation environment. The best installation way the paper considered is vertical; if installed horizantally, the outlet end of the meter must be a 1-2 m long straight-line segment, and a gauge pressure of 20 kPa maitained. The heavy metering error will be produced with the product oil e-vaporated passing through the flowmeter, so, the back pressure of flowmeter has to be increased to reduce evaporation and avoid vibration of flowmeter.