Malfunction diagnosis of sludge deposition in standard orifice plate flowmeter

For sludge deposition of standard orifice plate, this paper puts forward the problem of online malfunction diagnosis. Based on calculation of normal working condition and malfunction condition of orifice plate, the relationship between deviation value of the orifice plate discharge coefficient and deposition degree have been concluded by CFD software. In order to implement online diagnosis, another detecting point is installed on downstream of the pressure detecting point of flange. The differential pressure ratio of factor (k) has been calculated which reflects the degree of distortion in flow field caused by deposition. Through analysis of simulation data, empirical formula about factor k with deposition degree Yu has been drawn. Through the formula, online diagnosis of deposition and correction of the measured value can be realized. Real flow experiments verify the effectiveness of the method and its practicability in engineering.