CN-121856325-B - Method and system for detecting appearance defects of earthing type liquefied hydrocarbon storage tank

CN121856325BCN 121856325 BCN121856325 BCN 121856325BCN-121856325-B

Abstract

The invention relates to the technical field of intelligent sensors and discloses a method and a system for detecting appearance defects of a soil-covered liquefied hydrocarbon storage tank, wherein the method comprises the steps of obtaining surface temperature distribution data above a soil-covered layer, generating an initial temperature sequence, separating medium-high frequency disturbance components, determining a soil heat capacity delay effect parameter and correcting the temperature sequence; the method comprises the steps of obtaining a pure thermal anomaly signal by stripping the thermal physical influence of soil when the temperature exceeds a temperature difference threshold, restoring a thermal distribution rule, mapping the thermal distribution rule to a three-dimensional coordinate system of a storage tank, determining a preliminary boundary of a defect, precisely positioning the damage position of an anticorrosive coating through gradient calculation, fusing heat insulation attribute data with a fire risk assessment model, and generating an early warning report containing the defect position, risk level and processing advice. The method can realize accurate and efficient detection of the appearance defects of the storage tank, and meets the requirements of high precision and continuity of safety monitoring.

Inventors

HUANG YU
ZHU JUNJUN
LI WEI
YUAN XINAN

Assignees

广东省特种设备检测研究院茂名检测院

Dates

Publication Date: 20260508
Application Date: 20260318

Claims (7)

1. The method for detecting the appearance defect of the earthing type liquefied hydrocarbon storage tank is characterized by comprising the following steps of: acquiring temperature distribution data of the earth surface of an area above the overburden layer; converting the temperature distribution data into a two-dimensional temperature field matrix, extracting transient temperature disturbance information, and generating an initial temperature sequence; Performing Fourier transformation on the initial temperature sequence, extracting a corresponding frequency spectrum, separating a middle-high frequency disturbance component, and determining a delay effect parameter caused by soil heat capacity according to the amplitude attenuation characteristic and the phase hysteresis rule of the middle-high frequency disturbance component; Performing time domain correction on the initial temperature sequence according to the delay effect parameter to obtain a corrected temperature sequence; Calculating the temperature difference between a local area and a peripheral area in the corrected temperature sequence, aligning the corresponding temperature distribution data with a ground surface temperature sequence acquired in real time if the temperature difference exceeds a preset temperature difference judging threshold value, and stripping the thermal physical influence of soil by establishing a heat exchange model to obtain a pure thermal anomaly signal; Inputting the pure thermal anomaly signal into a preset thermal distribution reduction model, reducing a thermal distribution rule caused by the damage of an anticorrosive coating, mapping the thermal distribution rule to a preset storage tank three-dimensional coordinate system, extracting an anomaly region coordinate, and determining a preliminary boundary of defect detection; Applying gradient calculation to the pure thermal anomaly signals in the primary boundary limiting analysis range, judging the corresponding relation between a gradient peak value and a thermal signal attenuation mode, and determining accurate positioning information of corrosion-resistant layer damage according to the corresponding relation; Fusing the positioning information and the pre-acquired natural heat insulation attribute data of the storage tank, inputting a preset fire risk assessment model, outputting a corresponding risk probability value, and generating a defect early warning report according to the amplitude of the risk probability value exceeding a preset probability judgment threshold; Wherein the initial temperature sequence is subjected to Fourier transformation, corresponding frequency spectrums are extracted, medium-high frequency disturbance components are separated, according to the amplitude attenuation characteristics and the phase lag law of the medium-high frequency disturbance components, determining delay effect parameters caused by soil heat capacity, wherein the delay effect parameters comprise: Carrying out segmentation processing on the initial temperature sequence, and extracting frequency spectrum distribution of each time period through Fourier transformation; separating a low-frequency background component and a medium-high frequency disturbance component in the frequency spectrum distribution to obtain a medium-high frequency thermal signal; the frequency band of the medium-high frequency heat signal is subdivided, sub-band energy distribution characteristics of energy with exponential decay trend along with time are extracted, and amplitude decay sequences are formed by time sequence integration; performing exponential fitting on the amplitude attenuation sequence, calculating an attenuation rate constant and a phase lag time value to form a characteristic parameter set, and determining a delay effect parameter; The step of applying gradient calculation to the pure thermal anomaly signal in the primary boundary limiting analysis range, judging the corresponding relation between a gradient peak value and a thermal signal attenuation mode, and determining accurate positioning information of the damage of the anti-corrosion layer according to the corresponding relation comprises the following steps: carrying out gradient calculation on the pure thermal anomaly signals in the primary boundary limiting analysis range, and extracting spatial gradient intensity distribution to obtain a gradient amplitude value sequence; Performing multi-scale sampling analysis on the gradient amplitude value sequence along the radial direction to obtain a corresponding relation set of the gradient peak value position and the thermal signal intensity attenuation gradient; reserving candidate damaged boundary points, wherein the signal intensity attenuation rate at the radial gradient peak position exceeds a preset attenuation judgment threshold value, and the peak amplitude is larger than the preset amplitude judgment threshold value, so as to form a positioning outline of the damage of the anticorrosive coating; And carrying out superposition verification on the positioning profile and the attenuation characteristic of the pure thermal anomaly signal to obtain accurate positioning information of the damage of the anticorrosive coating.
2. The method for detecting the appearance defect of the earthing type liquefied hydrocarbon storage tank according to claim 1, wherein the step of acquiring the temperature distribution data of the earth surface of the area above the earth covering layer comprises the steps of: carrying out full coverage acquisition on the earth surface of the area above the soil covering layer through a multispectral infrared sensor array to acquire original temperature data and spatial position information; denoising the original temperature data to obtain denoising temperature data; and integrating the denoising temperature data and the space position information to form temperature distribution data of the earth surface.
3. The method for detecting the appearance defect of the earthing type liquefied hydrocarbon storage tank according to claim 1, wherein the converting the temperature distribution data into a two-dimensional temperature field matrix and extracting transient temperature disturbance information to generate an initial temperature sequence comprises: Storing the temperature distribution data as a two-dimensional temperature field matrix containing temporal and spatial information; Separating a background temperature change component caused by soil thermal inertia from the two-dimensional temperature field matrix through time differential filtering, and extracting transient temperature disturbance information; And integrating the transient temperature disturbance information in time sequence to generate an initial temperature sequence.
4. The method for detecting the appearance defect of the earthing liquefied hydrocarbon storage tank according to claim 1, wherein the performing time-domain correction on the initial temperature sequence according to the delay effect parameter to obtain a corrected temperature sequence comprises: performing time domain segmentation on the initial temperature sequence to obtain a plurality of time windows; Applying the delay effect parameters to the data in the time windows to compensate, and generating an intermediate temperature sequence of preliminary time domain correction; performing Fourier transform and frequency domain analysis on the intermediate temperature sequence, extracting main frequency components in each time window, and separating low-frequency smooth components related to thermal resistance characteristics to obtain frequency characteristic distribution; Performing weighted calculation on the frequency characteristic distribution, and generating weighted characteristic distribution by taking a negative correlation value of the low-frequency energy duty ratio as a weight; and carrying out secondary correction on the intermediate temperature sequence through the weighted characteristic distribution to obtain a corrected temperature sequence.
5. The method for detecting the appearance defect of the earthing type liquefied hydrocarbon storage tank according to claim 1, wherein the calculating the temperature difference between the local area and the peripheral area in the corrected temperature sequence, if the temperature difference exceeds a preset temperature difference judgment threshold, aligns the corresponding temperature distribution data with a surface temperature sequence acquired in real time, and peels off the soil thermophysical influence by establishing a heat exchange model to obtain a pure thermal anomaly signal comprises: dividing local areas of the corrected temperature sequence to obtain a plurality of local temperature difference point sets; calculating the temperature difference value of each local area and the peripheral area based on the local temperature difference point set, and marking the temperature difference value as an abnormal area if the temperature difference value exceeds a preset temperature difference judging threshold value to form an abnormal area set; the abnormal region set is aligned with a ground surface temperature sequence acquired in real time in a time sequence mode, and a ground surface temperature reference sequence is generated; establishing a heat exchange model according to the earth surface temperature reference sequence, inputting temperature data corresponding to the abnormal region set into the heat exchange model, and separating soil thermophysical components to obtain a preliminary pure thermal abnormal signal; and performing frequency spectrum filtering on the preliminary pure thermal anomaly signal to filter residual low-frequency components, thereby obtaining a final pure thermal anomaly signal.
6. The method for detecting the appearance defect of the earthing-type liquefied hydrocarbon storage tank according to claim 1, wherein the steps of fusing the positioning information with the pre-acquired natural thermal insulation attribute data of the storage tank, inputting a preset fire risk assessment model, outputting a corresponding risk probability value, and generating a defect early warning report according to the amplitude of the risk probability value exceeding a preset probability judgment threshold value, include: acquiring natural heat insulation attribute distribution data of the tank wall according to the positioning information, and obtaining a space distribution characteristic set of a heat insulation weakened area through space superposition operation; Matching the spatial distribution feature set with heat conduction parameters in a preset fire risk assessment model, and obtaining a probability value set of thermal runaway propagation of each defect position through multi-layer hot air risk propagation simulation; Extracting corresponding defect positions exceeding a preset probability judgment threshold value in the probability value set, and determining a comprehensive security influence level value; and correlating the comprehensive security influence level value with the stability parameter of the whole structure of the storage tank, and generating a defect early warning report containing defect positions, risk levels and processing suggestions.
7. An earth-covered liquefied hydrocarbon storage tank appearance defect detection system, for implementing the method of any one of claims 1-6, comprising: the temperature distribution acquisition module is used for acquiring temperature distribution data of the earth surface of the area above the overburden layer; The temperature sequence generation module is used for converting the temperature distribution data into a two-dimensional temperature field matrix, extracting transient temperature disturbance information and generating an initial temperature sequence; the delay parameter determining module is used for carrying out Fourier transformation on the initial temperature sequence, extracting corresponding frequency spectrums, separating medium-high frequency disturbance components, and determining delay effect parameters caused by soil heat capacity according to the amplitude attenuation characteristics and the phase hysteresis rules of the medium-high frequency disturbance components; the time domain correction module is used for performing time domain correction on the initial temperature sequence according to the delay effect parameter to obtain a corrected temperature sequence; The abnormal signal extraction module is used for calculating the temperature difference value between the local area and the peripheral area in the corrected temperature sequence, aligning the corresponding temperature distribution data with the ground surface temperature sequence acquired in real time if the temperature difference value exceeds a preset temperature difference judgment threshold value, and stripping the soil thermophysical influence by establishing a heat exchange model to obtain a pure thermal abnormal signal; The preliminary boundary determining module is used for inputting the pure thermal anomaly signal into a preset thermal distribution reduction model, reducing a thermal distribution rule caused by the damage of the anticorrosive coating, mapping the thermal distribution rule to a preset storage tank three-dimensional coordinate system, extracting an anomaly region coordinate, and determining a preliminary boundary of defect detection; The accurate positioning module is used for applying gradient calculation to the pure thermal anomaly signals in the primary boundary limiting analysis range, judging the corresponding relation between a gradient peak value and a thermal signal attenuation mode, and determining accurate positioning information of the damage of the anti-corrosion layer according to the corresponding relation; the early warning report generation module is used for fusing the positioning information with the pre-acquired natural heat insulation attribute data of the storage tank, inputting a preset fire risk assessment model, outputting a corresponding risk probability value, and generating a defect early warning report according to the amplitude that the risk probability value exceeds a preset probability judgment threshold value.

Description

Method and system for detecting appearance defects of earthing type liquefied hydrocarbon storage tank Technical Field The invention relates to the technical field of intelligent sensors, in particular to an appearance defect detection and system for an earthing type liquefied hydrocarbon storage tank. Background At present, in the field of intelligent sensors, with the continuous expansion of the energy reserve scale and the continuous improvement of the safety operation and maintenance requirements of a storage tank, the appearance defect detection of the earthing type liquefied hydrocarbon storage tank is used as a core link for guaranteeing the safety operation of equipment, and the energy storage safety and the surrounding environment stability are directly related. The existing method for detecting the appearance defects of the earthing type liquefied hydrocarbon storage tank in the industry mainly relies on manual excavation inspection or single infrared scanning, for example, flaw detection is carried out by excavating an exposed tank body periodically, or the surface temperature is collected by adopting common infrared equipment and is not subjected to advanced treatment, or the effective stripping of the thermal inertia interference of soil is lacking. However, this approach presents significant drawbacks in complex operating environments. Because the manual excavation cost is high, the period is long, continuous monitoring cannot be realized, single infrared scanning is easily influenced by soil heat capacity delay and thermal resistance smoothness, weak defect signals are covered, signal correction is not carried out on soil thermophysical characteristics, environmental interference and real defect signals are difficult to distinguish, misjudgment and omission are easy to occur particularly in a scene of thicker covering soil layer or soil humidity change, and the defect positions cannot be accurately positioned. To sum up, the prior art is difficult to realize accurate high-efficient detection of earthing formula liquefied hydrocarbon storage tank outward appearance defect, can't satisfy the high accuracy and the continuity demand to energy storage equipment safety monitoring. Disclosure of Invention The invention provides a method and a system for detecting the appearance defects of an earthing type liquefied hydrocarbon storage tank, which are used for realizing accurate and efficient detection of the appearance defects of the earthing type liquefied hydrocarbon storage tank and meeting the requirements of high precision and continuity for safety monitoring of energy storage equipment. In order to solve the technical problems, the present invention provides a method for detecting appearance defects of an earthing liquefied hydrocarbon storage tank, comprising: acquiring temperature distribution data of the earth surface of an area above the overburden layer; converting the temperature distribution data into a two-dimensional temperature field matrix, extracting transient temperature disturbance information, and generating an initial temperature sequence; Performing Fourier transformation on the initial temperature sequence, extracting a corresponding frequency spectrum, separating a middle-high frequency disturbance component, and determining a delay effect parameter caused by soil heat capacity according to the amplitude attenuation characteristic and the phase hysteresis rule of the middle-high frequency disturbance component; Performing time domain correction on the initial temperature sequence according to the delay effect parameter to obtain a corrected temperature sequence; Calculating the temperature difference between a local area and a peripheral area in the corrected temperature sequence, aligning the corresponding temperature distribution data with a ground surface temperature sequence acquired in real time if the temperature difference exceeds a preset temperature difference judging threshold value, and stripping the thermal physical influence of soil by establishing a heat exchange model to obtain a pure thermal anomaly signal; Inputting the pure thermal anomaly signal into a preset thermal distribution reduction model, reducing a thermal distribution rule caused by the damage of an anticorrosive coating, mapping the thermal distribution rule to a preset storage tank three-dimensional coordinate system, extracting an anomaly region coordinate, and determining a preliminary boundary of defect detection; Applying gradient calculation to the pure thermal anomaly signals in the primary boundary limiting analysis range, judging the corresponding relation between a gradient peak value and a thermal signal attenuation mode, and determining accurate positioning information of corrosion-resistant layer damage according to the corresponding relation; fusing the positioning information and the pre-acquired natural heat insulation attribute data of the storage tank, inputting a preset fire r