About one inverse problem on determination the hydraulic resistance of the pipeline
DOI:
https://doi.org/10.26577/JMMCS-2019-2-24Keywords:
main oil pipelines, inverse problem, high-viscosity and high-congealing oil, hydraulic resistance coefficient, Altshul formulaAbstract
The results of determining the law of hydraulic resistance of the pipe of the main oil pipeline are
provided. The method of «hot» transfer is considered one of the most reliable for transportation
of highly viscous and high- congealing (paraffin) oil. In the «hot» transfer of paraffin oil the
following occurs: 1) a decrease in temperature due to heat transfer with cold soil and an increase
in oil viscosity; 2) the change in the roughness of the pipe wall of the pipeline due to loss of
asphalt-resinous and paraffin deposits. These factors lead to the fact that the law of hydraulic
resistance of the pipeline in the form of Altshul needs to be corrected depending on the Reynolds
number and the degree of wall roughness.
The solution to the problem is sought by formulating an inverse problem to determine the law
of hydraulic resistance in the form of Altshul. The mathematical formulation of the problem
includes a system of equations of motion and heat transfer and a modified Altshul formula with
unknown coefficients. The system of the equation of motion and heat transfer is solved by a
numerical method, difference analogs of the equation of motion and heat transfer are calculated
by the method of characteristics and by the method of point-to-point computation, respectively.
In the calculations, there pressure, velocity and temperature distributions were determined, and
unknown coefficients of the modified Altshul formula were found by comparing the calculated and
actual data of the SCADA system. As a result of comparison of the calculated and experimental
data, the dependence of the hydraulic resistance coefficient on the Reynolds number and the
roughness of the pipeline wall were constructed. The agreement of the calculated data with the
actual indicators of the SCADA system allows indicating the reliability of the results of the
inverse problem method for determining the hydraulic resistance coefficient of the main oil pipeline.
