Patent ID: 11927495
Assignee: nan
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A system for contactless determination of mechanical stresses in a pipeline, comprising:
a device for contactless measurement of the mechanical stresses in the pipeline, comprising at least three devices for contactless measurement of a magnetic flux density and configured to move along an axis of the pipeline at a distance from the pipeline and subsequently transmit data on the mechanical stresses in the pipeline to a computing device, the data comprising information on a shape of a distribution of mechanical stresses;
wherein each of the at least three devices for contactless measurement of the magnetic flux density comprises an array of sensors configured to measure the magnetic flux density by performing a sequential contactless measurement of characteristic parameters along the axis of the pipeline, the characteristic parameters being represented by magnetic field induction gradients dB that characterize a change in the magnetic flux density passing through the array of sensors when the device for contactless measurement of the mechanical stresses moves along the axis of the pipeline at a distance from the pipeline;
wherein the first device for contactless measurement of the magnetic flux density is configured to perform the contactless measurement of the magnetic flux density in an YZ plane, the YZ plane defining an action area of transverse hoop stresses of the pipeline;
wherein the second device for contactless measurement of the magnetic flux density is configured to perform the contactless measurement of the magnetic flux density in an XY plane, the XY plane defining an action area of longitudinal horizontal stresses of the pipeline and bending moments;
wherein the third device for contactless measurement of the magnetic flux density is configured to perform the contactless measurement of the magnetic flux density in two XZ planes spaced apart from each other, the XZ planes defining an action area of longitudinal vertical stresses and bending moments,
wherein the contactless measurements take place simultaneously in the YZ, XY planes and the two XZ planes;, the computing device for determining the mechanical stresses, the computing device comprising a memory coupled to a processor, the computing device being configured to receive the data on the mechanical stresses in the pipeline from the device for contactless measurement of the mechanical stresses and transmit control data to the device for contactless measurement of the mechanical stresses via a data reception and transmission channel; wherein the processor is configured to:
a) receive, from the device for contactless measurement of the mechanical stresses in the pipeline, the characteristic parameters as the magnetic field induction gradients dB which characterize the change in the magnetic flux density;
b) calibrate the characteristic parameters based on the received data from the device for contactless measurement of the mechanical stresses, said calibration comprising determining calibration coefficients according to a known data, the calibration coefficients characterizing a magnetomechanical state of a homogeneous pipeline throughout the pipeline as a dependence of the change in the magnetic flux density on a change in a mechanical moment, the calibration coefficients being determined as ratios of magnetic and mechanical moments, said calibration being based on conditions of previously known differences in magnetic moments in two different cross-sections of the pipeline or known differences in the mechanical moments under conditions of a difference in an internal pressure or temperature;
c) calculate a distribution of mechanical stresses at each measure point throughout the pipeline by means of matrix transformations, wherein increments of a main stress vector at each measure point are determined based on the matrix transformations, wherein the transverse hoop, longitudinal horizontal and longitudinal vertical stresses are calculated separately as projections of the main stress vector on the corresponding planes lying in the action area of the stresses; and
d) determine the mechanical stresses in the pipeline based on the calculated distribution of mechanical stresses at each measure point throughout the pipeline, wherein anomalies are determined at given criteria for limit values of the mechanical stresses, wherein a maximum deviation from permissible values of the mechanical stresses is used to determine a concentration value of the mechanical stresses, and the shape of the distribution of mechanical stresses is used to determine a type of an anomaly source;
wherein the memory comprises a database of mechanical stresses in the pipeline and configured to receive, from the processor, and store the characteristic parameters as the magnetic field induction gradients dB, the determined calibration coefficients and the calculated distributions of mechanical stresses at each measure point throughout the pipeline.