CN-121994915-A - Gas pipeline flaw detection equipment and flaw detection method thereof

CN121994915ACN 121994915 ACN121994915 ACN 121994915ACN-121994915-A

Abstract

The invention relates to the technical field of nondestructive testing, and discloses gas pipeline flaw detection equipment and a flaw detection method thereof, wherein the method comprises the steps of firstly calculating a gap coupling coefficient based on the thickness of an anticorrosive coating and the lifting distance of a probe, and simultaneously obtaining a working condition dynamic coefficient according to the temperature of the probe, the scanning speed and the temperature rise of a coil; and then, the signal uniformity and the real-time signal-to-noise ratio are combined to calculate the self-adaptive adjusting factor reflecting the quality of the current detection condition. On the other hand, a theoretical frequency base is determined based on the pipe thickness, the material conductivity, and the target defect depth. And finally, dynamically calculating the optimal target eddy current detection excitation frequency and adjusting in real time by fusing the self-adaptive adjusting factor and the theoretical frequency base. The invention realizes systematic modeling and real-time fusion of multidimensional influence parameters, solves the problems of unstable sensitivity and easy omission in the complex dynamic environment of the traditional fixed frequency detection method, and remarkably improves the reliability, consistency and precision of the full-line flaw detection of the gas pipeline.

Inventors

Ren Wenxiong
ZHONG ZHENYANG
CHEN XUN
JIA XIN
LIU HUILING
WANG JIAFA
GAN FU
JI SHIQI
PENG SHAOQUAN
SHI HAOYING

Assignees

武汉明臣焊接无损检测有限公司

Dates

Publication Date: 20260508
Application Date: 20260305

Claims (8)

1. The gas pipeline flaw detection method is characterized by comprising the following steps of: Calculating and obtaining a gap coupling coefficient based on the thickness of the gas pipeline anticorrosive coating and the distance from the probe to the surface of the pipeline; Calculating and acquiring a working condition dynamic coefficient based on the probe temperature, the detection scanning speed and the probe coil temperature rise; calculating and obtaining an adaptive adjustment factor based on the gap coupling coefficient, the working condition dynamic coefficient, the signal uniformity and the real-time signal-to-noise ratio; Calculating and obtaining a theoretical frequency base based on the thickness of the gas pipeline, the conductivity of the gas pipeline material and the target defect depth; and calculating and acquiring the excitation frequency of the target eddy current detection based on the self-adaptive adjustment factor and the theoretical frequency base, and adjusting the excitation frequency of the current eddy current detection to the excitation frequency of the target eddy current detection.
2. The gas pipeline inspection method according to claim 1, wherein the method for calculating the excitation frequency of the target eddy current inspection is as follows: And calculating and obtaining the excitation frequency of the target eddy current detection through an exponential mapping relation based on the self-adaptive adjustment factor and the theoretical frequency base and combining an upper limit and a lower limit of the excitation frequency supported by system hardware.
3. The gas pipeline inspection method according to claim 2, wherein the theoretical frequency base is used for indicating a normalized position of a theoretical optimal frequency in a system frequency range, and the adaptive adjustment factor is used for dynamically modulating the theoretical frequency base to determine a final target frequency mapping point.
4. The gas pipeline inspection method according to claim 2, wherein the mode of calculating and obtaining the theoretical frequency base is as follows: performing ratio processing on the target defect depth and the thickness of the gas pipeline to obtain a defect depth ratio; Calculating theoretical optimal frequency based on the thickness of the gas pipeline, the conductivity of the material, the relative permeability and the defect depth ratio; And carrying out normalized mapping on the calculated theoretical optimal frequency based on the upper limit and the lower limit of the excitation frequency supported by system hardware to obtain a theoretical frequency base number with the value ranging from 0 to 1, wherein the base number and the upper limit and the lower limit of the system frequency are in monotonic corresponding relation.
5. The gas pipeline inspection method according to claim 2, wherein the method for calculating the adaptive adjustment factor is as follows: Performing ratio processing on the real-time signal-to-noise ratio and a target signal-to-noise ratio threshold required by a system, and acquiring the real-time signal-to-noise ratio standard rate after adopting a min function limiting upper limit of 1; Based on the gap coupling coefficient and the real-time signal-to-noise ratio standard reaching rate, taking the minimum value of the gap coupling coefficient and the real-time signal-to-noise ratio standard reaching rate to obtain a penetration priority for representing penetration requirements; Based on the working condition dynamic coefficient and the signal uniformity, taking the geometric average value of the working condition dynamic coefficient and the signal uniformity to obtain a resolution priority item representing the resolution requirement; And the self-adaptive adjustment factor comprehensively reflects the total influence of the current detection condition on the frequency selection strategy, and the closer the value is to 1, the more the frequency is more prone to adopting the frequency close to the theoretical optimal.
6. The gas pipeline flaw detection method according to claim 5, wherein the mode of calculating and obtaining the dynamic coefficient of the working condition is as follows: Carrying out ratio processing on the absolute value of the difference value between the current probe temperature and the standard reference temperature and the absolute value of the allowable maximum temperature deviation, and taking the complement of the ratio as a temperature normalization factor; Performing ratio processing on the current detection scanning speed and the maximum allowable scanning speed designed by the system, and taking the complement of the ratio as a speed normalization factor; Performing ratio processing on the current probe coil temperature rise and the maximum safe temperature rise allowed by the coil, and taking the complement of the ratio as a coil temperature rise normalization factor; and carrying out weighted geometric average on the temperature factors, the speed factors and the temperature rise factors according to preset weight coefficients to obtain comprehensive working condition dynamic coefficients, and quantifying the comprehensive influence of the current dynamic working conditions on the detection stability.
7. The gas pipeline inspection method according to claim 5, wherein the method for calculating and obtaining the gap coupling coefficient is as follows: based on the sum of the thickness of the gas pipeline anticorrosive coating and the distance from the probe to the surface of the pipeline, calculating to obtain a gap coupling coefficient through an exponential decay relation by combining a preset reference constant; The coefficient monotonically decreases with increasing total gap for quantifying the degree of attenuation of the electromagnetic coupling efficiency.
8. A gas pipeline inspection apparatus, characterized in that the gas pipeline inspection apparatus comprises: A memory for storing executable instructions; a processor for implementing the gas pipeline inspection method of any one of claims 1-6 when executing the executable instructions stored in the memory.

Description

Gas pipeline flaw detection equipment and flaw detection method thereof Technical Field The invention belongs to the technical field of nondestructive testing, and particularly relates to gas pipeline flaw detection equipment and a flaw detection method thereof. Background The structural integrity of gas pipelines, which are the key infrastructure for urban energy delivery, has a decisive impact on public safety and operating efficiency. Eddy current detection technology has become a common means for corrosion and crack detection of the outer wall of steel gas pipelines by virtue of non-contact operation, high sensitivity characteristics and excellent identification capability of surface and near-surface defects. However, the traditional eddy current detection method mainly relies on static parameters such as pipeline materials, wall thickness and the like to preset fixed excitation frequency for scanning, and is difficult to adapt to dynamic changes in the actual running environment of the gas pipeline. Specifically, the thickness of the anti-corrosion coating on the outer wall of the pipeline has obvious difference, and the actual lifting distance between the probe and the pipeline wall continuously fluctuates due to mechanical vibration, surface unevenness or operation factors in the detection process, so that the electromagnetic coupling state is unstable, and the signal intensity and the signal-to-noise ratio are seriously weakened. Meanwhile, the temperature of the pipeline and the probe, the detection travelling speed and other working condition parameters change in real time, and the fluctuation directly influences the spatial distribution and time response characteristics of the vortex field, so that signal characteristic drift is caused. In addition, physical parameters such as conductivity, permeability, etc. of the pipe material may exhibit spatial non-uniformity due to manufacturing process, stress distribution, or environmental aging, further exacerbating detection complexity. In the prior art, compensation is attempted to be carried out aiming at a single factor (such as a lift-off effect) or a multi-frequency fusion strategy is adopted, but systematic defects generally exist, namely, on one hand, a comprehensive mathematical model of the coupling influence of multi-dimensional parameters such as coating thickness, lift-off distance, working condition parameters, material characteristics and the like cannot be established, and on the other hand, a dynamic frequency adjustment mechanism based on real-time detection data is lacked. Therefore, in actual detection, the fixed or semi-static frequency strategy cannot maintain the optimal detection state in the whole line, and is prone to generate a missing detection risk in a section with serious dynamic interference (such as a large gap, high temperature or high speed scanning), or reduces the defect resolution in a section with stable conditions due to frequency selection deviation, so that the reliability, consistency and accuracy of the detection result cannot meet the actual engineering requirements. In view of the above, there is a need in the art for improvements. Disclosure of Invention The embodiment of the invention aims to provide a gas pipeline flaw detection device and a flaw detection method thereof, and aims to solve the problems. The gas pipeline flaw detection method comprises the following steps of calculating and obtaining a gap coupling coefficient based on the thickness of a gas pipeline anticorrosive layer and the distance from a probe to the surface of a pipeline, calculating and obtaining a working condition dynamic coefficient based on the temperature of the probe, the detection scanning speed and the temperature rise of a probe coil, calculating and obtaining an adaptive adjustment factor based on the gap coupling coefficient, the working condition dynamic coefficient, signal uniformity and real-time signal-to-noise ratio, calculating and obtaining a theoretical frequency base based on the thickness of the gas pipeline, the conductivity of a gas pipeline material and the target flaw depth, calculating and obtaining the excitation frequency of target eddy current detection based on the adaptive adjustment factor and the theoretical frequency base, and adjusting the excitation frequency of the current eddy current detection to the excitation frequency of the target eddy current detection. According to the further technical scheme, the method for calculating and obtaining the excitation frequency of the target eddy current detection is that the excitation frequency of the target eddy current detection is obtained through calculation through an exponential mapping relation based on the self-adaptive adjusting factor and the theoretical frequency base and combined with an upper limit and a lower limit of the excitation frequency supported by system hardware. According to a further technical scheme, the adaptive adjustment facto