| 摘要 |
FIELD: measuring equipment.SUBSTANCE: invention relates to measurement equipment and is intended for determining the flow rate of a medium in round pipes at balanced flow. Method for determining the flow rate in pipelines involves measurement of the flow rate at two characteristic points along the section area of the pipe and determination of the flow rate on the basis of these measurement results. Distinctive feature of the method is that the medium flow rate at any point of the flow along the section area of the pipe is measured; using the integrated universal logarithmic profile U=Aln(x)+Bthe values of Aand Bcoefficients are determined for each pair of known values of coordinates (distances from the pipe wall) of the points of rate measurement and the measured rate values at these points (,) and (,), relative differences between the values of coefficients of Aand Bare determinedand(upper indices mean the values of Aand Bcoefficients, calculated for various pairs of coordinate-rate values), provided that the valuesandfor each pair of values of Aand Bdo not exceed the preset value ε, heat carrier flow rate is determined using the formula:,where r=r-x - distance from the centre of the pipe; ris the radius of the pipe; x is the distance from the pipe wall;is the average value of Acoefficients;is an average of Bcoefficients ; n=3; κ is the karman constant; ν - kinematic viscosity of the medium; δ-thick sublayer thickness.EFFECT: technical result is increase of accuracy.1 cl, 1 dwg, 1 tbl |
