Oil and gas pipeline defect magnetic flux leakage fixed-point early warning detection system

Abstract

The invention belongs to the technical field of pipeline magnetic flux leakage detection, and particularly relates to an oil and gas pipeline defect magnetic flux leakage fixed-point early warning detection system. In order to realize accurate early warning and monitoring of defects and damages of oil and gas pipelines, the invention designs a digital defect and damage fixed-point early warning and detection system capable of realizing magnetic flux leakage of the oil and gas pipelines on the basis of a metal magnetic flux leakage detection principle. A system program intelligently controls an exciting coil and a plurality of groups of Hall sensors densely distributed on a detected pipe section, pipeline defect damage magnetic flux leakage detection signals are generated under a high-intensity magnetic field, digital conversion and acquisition of the signals are carried out, and then tangential and normal detection signal processing and analysis programs of the detection signals are written, so that the pipeline defect damage magnetic flux leakage detection precision is improved. And full-digital defect damage real-time fixed-point detection early warning and positioning analysis are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of pipeline magnetic leakage detection, and in particular relates to a fixed-point early warning detection system for magnetic leakage of oil and gas pipeline defects. Background Art

[0002] With the development of society, the total mileage of oil and gas pipelines in my country is becoming increasingly large, and the number of newly built pipelines is increasing. Due to the precipitation of the medium transported by the oil and gas pipelines and the corrosion of the oil and gas pipelines themselves, defects and damage are easy to occur. Defect damage will reduce the structural strength of the oil and gas pipelines, and it is easy to rupture under the action of internal pressure or external load, causing huge economic losses. Therefore, it has become a strong problem to carry out long-term real-time non-destructive defect detection on key pipeline parts to reduce the occurrence of accidents such as pipeline rupture and leakage. As the mainstream detection technology for pipeline detection, magnetic flux leakage detection can accurately detect the defect size of volume defects of pipelines that have formed and have not formed leakage points, so as to achieve the purpose of accurate early warning analysis. It has good penetration and can detect pipelines wrapped by coatings and other coverings without removing the covering layer. However, the current application of magnetic flux leakage detection technology is mainly for detection in oil and gas pipelines, that is, the detector is pushed forward by liquid or gas media in the oil and gas pipelines, so as to perform magnetic flux leakage non-destructive detection on the oil and gas pipelines. However, this detection method is unidirectional and periodic, which cannot meet the needs of long-term real-time magnetic flux leakage non-destructive detection for the vulnerable and core pipeline parts that are of key concern. In addition, traditional magnetic flux leakage detection mostly uses analog signals for transmission and data processing, which leads to problems such as large amount of hardware, complex structure, high cost, and limited detection accuracy. Summary of the invention

[0003] In view of the above problems, the present invention uses a system program to intelligently control the excitation coil and multiple groups of Hall sensors densely distributed on the detected pipe section, generates pipeline defect damage leakage magnetic detection signals under a strong magnetic field, and performs digital conversion and acquisition of the signals. Based on the principle of metal leakage magnetic detection, a tangential and normal detection signal processing and analysis program is written to realize full digital defect damage real-time fixed-point detection warning and positioning analysis, and an oil and gas pipeline defect leakage magnetic fixed-point warning detection system is designed.

[0004] To achieve the above-mentioned purpose, the system structure of the present invention includes a hardware control system, an excitation coil, a load-bearing shell, a sliding component, a detector bearing plate, and multiple groups of Hall sensors, wherein the hardware control system is installed between the detector bearing plate and the load-bearing shell; the excitation coil is used to excite the pipeline; the load-bearing shell is used to protect the internal circuit and maintain the stability of the detector; the sliding component is used for installing and disassembling the detector; the detector bearing plate is composed of packaging materials and a heat sink, and is used to fix multiple groups of Hall sensor detection probes; and the multiple groups of Hall sensors are used to collect leakage magnetic signals at different test points on the surface of the oil and gas pipeline. This system contains a control center program, which is responsible for the calculation analysis and program call of the whole system; it contains an information collection program, which controls multiple sets of Hall sensors, multiple sets of wave stabilization and purification systems, multiple sets of photoelectric transmission systems, and digital signal generation and acquisition systems to collect, stabilize, purify, transmit and digitally convert the leakage magnetic detection signals on the surface of the oil and gas pipeline; it contains a signal optimization program, which can further digitally filter the collected digital leakage magnetic signals to eliminate interference factors; it contains a tangential and normal detection signal processing and analysis program, which can complete the defect damage degree detection and damage location functions based on the leakage magnetic defect detection characteristics, and use the display function and alarm system of the PC terminal to display, locate and warn the defects and damage of the oil and gas pipeline in real time. The system software sets ELECCQ1 as the leakage magnetic detection data storage area; ELECCQ2 as the filter processing data storage area; ELECCQ3 as the abnormal address storage area; ELECCQ4 as the abnormal value storage area; LINEADR as the critical value comparison unit.

[0005] The hardware control system includes multiple groups of Hall sensors, multiple groups of wave stabilization purification systems, multiple groups of photoelectric transmission systems, digital signal generation and collection systems, timing device systems, PC terminals, auxiliary storage systems, excitation coils, alarm systems, data security systems, and microcontrollers. The key points of its structure are that the output ports of multiple groups of Hall sensor circuits are connected to the input ports of multiple groups of wave stabilization purification systems, and then connected to the input ports of multiple groups of photoelectric transmission systems; the output ports of multiple groups of photoelectric transmission systems are connected to the input ports of digital signal generation and collection systems; the detection signal output ports of digital signal generation and collection systems are connected to the detection signal input ports of microcontrollers; the signal output ports of timing device systems are connected to the signal input ports of microcontrollers; the signal input and output ports of PC terminals are connected to the signal output and input ports of microcontrollers; the storage signal input port of the auxiliary storage system is connected to the storage signal output port of the microcontroller; the excitation coil is connected to the signal output port of the microcontroller; the signal input port of the alarm system is connected to the alarm signal output port of the microcontroller; the signal input port of the data security system is connected to the signal output port of the microcontroller.

[0006] The control center program first sets system parameters such as acquisition time setting, filter parameter setting and critical value setting, defines ELECCQ1 as the data storage area for leakage detection, and defines ELECCQ2 as the data storage area for filtering processing, completing the system parameter setting and the definition of the storage area. The sensor is defined by the for loop int i=0; i<1; i++ and the N value int N=i, the sensor probe is turned on, and R2 points to the storage area ELECCQ2. The system turns on the Nth probe with printf("The %dth probe has been turned on\n", N), and the N value changes from 1 to 48 cycles with the program, so as to complete the cyclic switching of different probes. The excitation coil is turned on to excite the pipeline, and the information collection program is called. By controlling multiple sets of Hall sensors, multiple sets of wave stabilization purification systems, multiple sets of photoelectric transmission systems, and digital signal generation and acquisition systems, the system functions such as leakage magnetic data acquisition, wave stabilization purification, photoelectric transmission, and signal digital conversion are completed, and the collected and processed digital leakage magnetic signals are stored in the storage area ELECCQ1 to complete the preliminary acquisition of leakage magnetic data. Then the signal optimization program is called to perform digital calculation and benchmark numerical processing on the digital magnetic leakage signal in the storage area ELECCQ1, so as to realize further digital filtering of the digital magnetic leakage signal, and store the filtered detection data in the storage area ELECCQ2 to wait for system call. Through R2 pointing to the next storage space of the storage area ELECCQ2, the next detection probe is turned on, and the switching of the magnetic leakage detection probe is further completed. Finally, the tangential and normal detection signal processing and analysis program is called to locate the damage through the matrix distribution equation, compare the data in the storage area ELECCQ2 with the critical value set in the parameter setting, find the magnetic leakage detection probe that exceeds the critical value, and use the detection data of the storage area ELECCQ3 pointed to by R3 and the storage area ELECCQ4 pointed to by R4 to display the specific magnetic leakage data and the location of the sensor collected by the detection probe in real time through the PC terminal, and realize the synchronous warning of abnormal signals through the alarm system, so as to realize defect damage detection, precise positioning and real-time warning.

[0007] The information collection program first defines the high-intensity interference threshold, the purpose is to eliminate the large external interference, make the collected data more reliable, clear the R5 register, point R1 to the first address ELECCQ1 of the leakage magnetic detection data storage area, and complete the definition of the interference threshold and storage area. Start the IN0 channel, through multiple sets of Hall sensors, multiple sets of wave stabilization purification systems, multiple sets of photoelectric transmission systems, and digital signal generation and collection systems, to collect the leakage magnetic detection signal, wave stabilization purification, photoelectric transmission, and digital conversion of the leakage magnetic signal. Delay waiting for one second to ensure that the leakage magnetic data has completed the digital conversion, and store the converted value in the area pointed to by R1. Compare and analyze the R1 pointing value with the high-intensity interference threshold to determine whether the collected value is greater than the interference threshold. If the collected value is greater than the interference threshold, the collected data is abandoned, the R1 pointing value is set to zero, and the leakage magnetic data is collected again, and the IN0 channel is restarted for signal digital conversion. If the collected data is not greater than the interference threshold, the R5 count is increased by one, the collected digital leakage magnetic signal is judged for the interference threshold, and the collected data that meets the threshold is sent to the storage area ELECCQ1 to achieve the purpose of accurate collection and storage of detection data. Finally, determine whether R5 is 60. If R5 is not 60, point R1 to the next storage unit, re-collect the leakage magnetic data and restart the IN0 channel for signal digital conversion. If R5 is 60, it means that the collection of digital leakage magnetic signals has been completed, and return to the control center program. Then, the collected data is subjected to wave stabilization purification, photoelectric transmission, and signal digital conversion to form a digital leakage magnetic signal, and after the interference threshold is judged, it is sent to the leakage magnetic detection storage area ELECCQ1 to wait for the control center program to call.

[0008] The signal optimization program first clears registers R5, R6, and R7, sets register R8 to 1, defines the maximum number of loops max loop1 and max loop2, and completes the definition of registers and the maximum number of loops. Point R1 to the first address ELECCQ1 of the magnetic flux leakage detection storage area, add the value of R7 to R6, and then clear R7. Determine whether the value of R6 is equal to max loop1. If it is not equal to max loop1, assign the value pointed to by R1 to R5, point R1 to the next storage unit, and count R7 plus one to determine whether R5 is greater than the value pointed to by R1. If it is greater, swap the two values. If it is not greater, directly determine whether R7 is equal to maxloop2. If it is not equal to max loop2, select R1 to point to the next storage unit. If it is equal to max loop2, count R8 plus one and point R1 to the first address of the storage area for the next round of data processing. Through the two cycles of max loop1 and max loop2, the digital magnetic flux leakage signals collected by the storage area ELECCQ1 are arranged in order according to their numerical values. If it is equal to max loop1, R4 and R5 are cleared, R1 is pointed to the 30th value in the storage area, and the value is defined as the reference number B. Then R1 is pointed to the first address of the storage area ELECCQ1, and calculation is performed. R4 is added to the value pointed to by R1 and then the reference number B is subtracted. After adding one to the R5 count, it is determined whether R5 is equal to 60. The sorted digital magnetic leakage signal detection data is processed by digital calculation for the reference value to achieve further digital filtering of the digital magnetic leakage signal. If not equal, R1 is pointed to the next storage unit and recalculated. If equal, the reference number B is added to R4 to obtain the final value of R4 and return to the control center program. Then the digital magnetic leakage signal in the storage area ELECCQ1 is further digitally filtered, and after the reference value processing, it is sent to R4 to wait for the system call.

[0009] The tangential and normal detection signal processing and analysis program first defines the abnormal address storage area ELECCQ3 and the abnormal value storage area ELECCQ4, defines the critical value comparison unit LINEADR, and points the R2, R3, and R4 pointers to the first address ELECCQ2 of the filtering data storage area, the first address ELECCQ3 of the abnormal address storage area, and the first address ELECCQ4 of the abnormal value storage area, respectively, and clears the R5 register to complete the definition of the storage area and register. After adding one to the R5 count, it is determined whether the R2 pointing value is greater than the critical value; if it is greater, the R2 pointing value is assigned to the R4 pointing position and the R5 value is assigned to the R3 pointing position, and the abnormal address *R3 and the abnormal value *R4 are displayed. At the same time, the alarm system is activated, and R3 and R4 are respectively pointed to the next storage unit. If not greater, R2 is directly pointed to the next storage unit and then it is determined whether R5 is equal to 48, and then the filtered data in the storage area ELECCQ2 is compared and analyzed with the critical value. If not equal, then R5 count is increased by one and the critical value is re-judged. If equal, R3 and R4 are pointed to the first address of their respective storage areas, and then it is judged whether *R4 is equal to 0. Then, by judging whether the value pointed to by R4 is 0, the data in the two storage areas are subjected to abnormal detection data analysis and sensor address analysis. If not equal, the abnormal address *R3 and abnormal value *R4 are cyclically displayed through the PC terminal. If equal, the PC terminal displays "None" and returns to the control center program. Find the probe that exceeds the critical value in the storage area ELECCQ2, and use the data in the storage area ELECCQ4 pointed to by R4 and the storage area ELECCQ3 pointed to by R3 as the degree of damage and damage location, and display it in real time through the PC terminal. When the critical value is exceeded, the alarm system is activated to realize the real-time early warning function.

[0010] As another preferred solution, the Hall sensor of the present invention adopts the F16500 model, including pin 1 for connecting to the power supply, pin 2 for grounding, and pin 3 for output. The sensor circuit includes a capacitor for filtering to make the output voltage more stable, and can transmit AC signals while blocking DC.

[0011] As another preferred solution, the wave stabilization purification system of the present invention comprises two parts: LM324 chip high-pass filter and LM324 chip low-pass filter. The LM324 operational amplifier is used for signal amplification. The high-pass filter attenuates signals below the cut-off frequency to remove low-frequency noise and extract rapidly changing signal components. The low-pass filter attenuates signals above the cut-off frequency and allows signals below the cut-off frequency to pass through, which is used to remove high-frequency noise and smooth signals.

[0012] As another preferred solution, the photoelectric transmission system of the present invention comprises two parts: a NE555D chip photoelectric transmitting circuit and a LM386M chip photoelectric receiving circuit. The photoelectric transmitting circuit is used to convert electrical signals into photoelectric optical signals, and the 8050 transistor is used to amplify the signal and control the on / off of the circuit; the photoelectric receiving circuit is used to receive the photoelectric optical signal, convert it into an electrical signal, and then amplify and filter it, and the LM386 power amplifier is used to amplify the low-power signal.

[0013] As another preferred solution, the digital signal generation and acquisition system of the present invention comprises a CS1232 signal digital conversion chip and a MAX4648 analog multi-way switch, wherein the CS1232 chip is used to convert analog signals into digital signals; and the MAX4648 is used to realize the switching of different analog signal sources. The excitation coil is used to establish a magnetic field to ensure the reliable operation of the system. The timing device system is used to provide synchronization signals and control data transmission for the digital system; the PC terminal is used to display the value and position of the final abnormal data; and the data security system is used to save data to prevent data loss due to power failure.

[0014] As another preferred embodiment, the alarm system of the present invention includes a 9014 type NPN transistor and a buzzer. The transistor is used to amplify the alarm signal, control the on and off of the alarm device, and realize circuit logic control; the buzzer emits a sound alarm. When the system detects an abnormal or dangerous situation, it drives the buzzer to sound, which serves as a warning.

[0015] As another preferred solution, the auxiliary storage system of the present invention comprises a 74HCT373 latch chip and an IS62WV12816BLL auxiliary storage chip. The 74HCT373 chip is used to store and maintain the input data of the detection system under the control of an enable signal. The IS62WV12816BLL chip is used to meet the needs of storing and processing a large amount of data.

[0016] Beneficial effects of the present invention:

[0017] 1. The present invention utilizes the intelligent control of multiple groups of Hall sensors and digital signal generation and acquisition systems densely distributed on the detection pipe section to generate and collect digital defect leakage magnetic detection signals, which not only ensures the digital acquisition of detection signals to serve the subsequent system digital analysis program, but also realizes the high-precision, long-term real-time fixed-point detection characteristics of detection signals. The stable wave purification system is used to achieve efficient batch detection and accurate data collection of detection points.

[0018] 2. The present invention writes a control center program to perform damage detection on pipeline defects. By calling the information collection program, the signal optimization program, and the tangential and normal detection signal processing and analysis program, the full digital detection of the leakage magnetic detection signal is realized, which reduces the number of hardware equipment used, reduces the operating cost of the detection system, and improves the system warning speed and detection accuracy.

[0019] 3. The present invention sets up a photoelectric transmission system to realize remote detection of remote pipelines, which solves the working conditions in remote and complex environments in the wild. The alarm system is set up to realize real-time early warning, which improves the reliability and effectiveness of the system. The auxiliary storage system is set up to expand the storage capacity of the detection equipment and has higher cost-effectiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. The protection scope of the present invention is not limited to the following description.

[0021] Figure 1 System structure diagram;

[0022] Figure 2 Hardware control system diagram;

[0023] Figure 3 Control center program flow chart;

[0024] Figure 4 Flowchart of information collection procedures;

[0025] Figure 5 Flowchart of signal optimization procedure;

[0026] Figure 6 Flow chart of tangential and normal detection signal processing and analysis program;

[0027] Figure 7 Hall sensor and its circuit diagram;

[0028] Figure 8 Circuit diagram of steady wave purification system;

[0029] Fig. 9 Circuit diagram of photoelectric transmission system;

[0030] Fig.10 Circuit diagram of digital signal generation and acquisition system;

[0031] Fig.11 Alarm system circuit diagram;

[0032] Fig.12 Auxiliary memory storage system circuit diagram. DETAILED DESCRIPTION

[0033] like Figure 1As shown, the system structure of the present invention includes a hardware control system 1, an excitation coil 2, a load-bearing shell 3, a sliding component 4, a detector bearing plate 5, and multiple groups of Hall sensors 6, wherein the hardware control system 1 is installed between the detector bearing plate and the load-bearing shell; the excitation coil 2 is used to excite the pipeline; the load-bearing shell 3 is used to protect the internal circuit and maintain the stability of the detector; the sliding component 4 is used for installing and disassembling the detector; the detector bearing plate 5 is composed of packaging materials and a heat sink, and is used to fix the detection probes of multiple groups of Hall sensors 6; and the multiple groups of Hall sensors 6 are used to collect leakage magnetic signals at different test points on the surface of the oil and gas pipeline. This system contains a control center program, which is responsible for the calculation analysis and program call of the whole system; contains an information collection program, which controls multiple sets of Hall sensors 6, multiple sets of wave stabilization purification systems 7, multiple sets of photoelectric transmission systems 8, and digital signal generation and collection systems 9 to collect, stabilize, purify, transmit and digitally convert the leakage magnetic detection signals on the surface of the oil and gas pipeline; contains a signal optimization program, which can further digitally filter the collected digital leakage magnetic signals to eliminate interference factors; contains a tangential and normal detection signal processing and analysis program, which can complete the defect damage degree detection and damage location functions based on the leakage magnetic defect detection characteristics, and use the display function of the PC terminal 11 and the alarm system 13 to display, locate and warn the defects and damage of the oil and gas pipeline in real time. The system software sets ELECCQ1 as the leakage magnetic detection data storage area; ELECCQ2 as the filter processing data storage area; ELECCQ3 as the abnormal address storage area; ELECCQ4 as the abnormal value storage area; LINEADR as the critical value comparison unit.

[0034] like Figure 2As shown, the hardware control system 1 includes multiple groups of Hall sensors 6, multiple groups of wave stabilization and purification systems 7, multiple groups of photoelectric transmission systems 8, digital signal generation and acquisition systems 9, timing device systems 10, PC terminals 11, auxiliary storage systems 12, excitation coils 2, alarm systems 13, data security systems 14, and microcontrollers 15. The key points of its structure are that the output ports of multiple groups of Hall sensor 6 circuits are connected to the input ports of multiple groups of wave stabilization purification systems 7, and then connected to the input ports of multiple groups of photoelectric transmission systems 8; the output ports of multiple groups of photoelectric transmission systems 8 are connected to the input ports of digital signal generation and acquisition systems 9; the detection signal output port of the digital signal generation and acquisition system 9 is connected to the detection signal input port of the microcontroller 15; the signal output port of the timing device system 10 is connected to the signal input port of the microcontroller 15; the signal input and output ports of the PC terminal 11 are connected to the signal output and input ports of the microcontroller 15; the storage signal input port of the auxiliary storage system 12 is connected to the storage signal output port of the microcontroller 15; the excitation coil 2 is connected to the signal output port of the microcontroller 15; the signal input port of the alarm system 13 is connected to the alarm signal output port of the microcontroller 15; the signal input port of the data security system 14 is connected to the signal output port of the microcontroller 15.

[0035] like Figure 3As shown, the control center program first sets system parameters such as acquisition time setting, filter parameter setting and critical value setting, defines ELECCQ1 as the data storage area for leakage detection, and defines ELECCQ2 as the data storage area for filtering processing, completing the system parameter setting and storage area definition. The sensor is defined by the for loop int i=0;i<1;i++ and the N value int N=i, the sensor probe is turned on, and R2 points to the storage area ELECCQ2. The system turns on the Nth probe with printf("%d probe has been turned on\n",N), and the N value changes from 1 to 48 cycles with the program, so as to complete the cyclic switching of different probes. Turn on the excitation coil 2 to excite the pipeline, call the information collection program, and complete the system functions such as leakage data collection, wave stabilization purification, photoelectric transmission, and signal digital conversion by controlling multiple sets of Hall sensors 6, multiple sets of wave stabilization purification systems 7, multiple sets of photoelectric transmission systems 8, and digital signal generation and collection systems 9, and the collected and processed digital leakage signals are stored in the storage area ELECCQ1 to complete the preliminary collection of leakage data. Then, the signal optimization program is called to perform digital calculation and benchmark numerical processing on the digital magnetic leakage signal in the storage area ELECCQ1, so as to realize further digital filtering of the digital magnetic leakage signal, and store the filtered detection data in the storage area ELECCQ2 to wait for the system call. Through R2, the next storage space of the storage area ELECCQ2 is pointed to, and the next detection probe is opened to further complete the switching of the magnetic leakage detection probe. Finally, the tangential and normal detection signal processing and analysis program is called to locate the damage through the matrix distribution equation, and the data in the storage area ELECCQ2 is compared with the critical value set in the parameter setting to find the magnetic leakage detection probe that exceeds the critical value, and the specific magnetic leakage data and the location of the sensor collected by the detection probe are displayed in real time through the PC terminal 11 through the detection data of the storage area ELECCQ3 pointed to by R3 and the storage area ELECCQ4 pointed to by R4, and the abnormal signal synchronous warning is realized through the alarm system 13, thereby realizing defect damage detection, precise positioning and real-time warning.

[0036] like Figure 4As shown, the information collection program first defines the high-intensity interference threshold, the purpose is to eliminate the large external interference, make the collected data more reliable, clear the R5 register, point R1 to the first address ELECCQ1 of the leakage magnetic detection data storage area, and complete the definition of the interference threshold and storage area. Start the IN0 channel, through multiple sets of Hall sensors 6, multiple sets of wave stabilization purification systems 7, multiple sets of photoelectric transmission systems 8, and digital signal generation and collection systems 9, to collect the leakage magnetic detection signal, stabilize the wave, purify, transmit the photoelectric, and digitally convert the leakage magnetic signal. Delay for one second to ensure that the leakage magnetic data has completed the digital conversion, and store the converted value in the area pointed to by R1. Compare and analyze the R1 pointing value with the high-intensity interference threshold to determine whether the collected value is greater than the interference threshold. If the collected value is greater than the interference threshold, the collected data is abandoned, the R1 pointing value is set to zero, and the leakage magnetic data is collected again, and the IN0 channel is restarted for signal digital conversion. If the collected data is not greater than the interference threshold, the R5 count is increased by one, the collected digital leakage magnetic signal is judged for the interference threshold, and the collected data that meets the threshold is sent to the storage area ELECCQ1 to achieve the purpose of accurate collection and storage of detection data. Finally, determine whether R5 is 60. If R5 is not 60, point R1 to the next storage unit, re-collect the leakage magnetic data and restart the IN0 channel for signal digital conversion. If R5 is 60, it means that the collection of digital leakage magnetic signals has been completed, and return to the control center program. Then, the collected data is subjected to wave stabilization purification, photoelectric transmission, and signal digital conversion to form a digital leakage magnetic signal, and after the interference threshold is judged, it is sent to the leakage magnetic detection storage area ELECCQ1 to wait for the control center program to call.

[0037] like Figure 5As shown in the figure, the signal optimization program first clears registers R5, R6, and R7, sets register R8 to 1, defines the maximum number of loops max loop1 and max loop2, and completes the definition of registers and maximum number of loops. Point R1 to the first address ELECCQ1 of the magnetic flux leakage detection storage area, add the value of R7 to R6, and then clear R7. Determine whether the value of R6 is equal to maxloop1. If it is not equal to max loop1, assign the value pointed to by R1 to R5, point R1 to the next storage unit, and add R7 count to determine whether R5 is greater than the value pointed to by R1. If it is greater, swap the two values. If it is not greater, directly determine whether R7 is equal to max loop2. If it is not equal to max loop2, select R1 to point to the next storage unit. If it is equal to max loop2, add R8 count to R1 and point R1 to the first address of the storage area for the next round of data processing. Through the two cycles of max loop1 and max loop2, the digital magnetic flux leakage signals collected by the storage area ELECCQ1 are arranged in order according to their numerical values. If it is equal to maxloop1, R4 and R5 are cleared, R1 is pointed to the 30th value in the storage area, and the value is defined as the reference number B. R1 is then pointed to the first address of the storage area ELECCQ1, and calculation is performed. R4 is added to the value pointed to by R1 and then the reference number B is subtracted. After the R5 count is increased by one, it is determined whether R5 is equal to 60. The sorted digital magnetic leakage signal detection data is processed by digital calculation for the reference value to achieve further digital filtering of the digital magnetic leakage signal. If not equal, R1 is pointed to the next storage unit and recalculated. If equal, the reference number B is added to R4 to obtain the final value of R4 and return to the control center program. Then the digital magnetic leakage signal in the storage area ELECCQ1 is further digitally filtered, and after the reference value processing, it is sent to R4 to wait for the system call.

[0038] like Figure 6As shown, the tangential and normal detection signal processing and analysis program first defines the abnormal address storage area ELECCQ3 and the abnormal value storage area ELECCQ4, defines the critical value comparison unit LINEADR, and points the R2, R3, and R4 pointers to the first address ELECCQ2 of the filter processing data storage area, the first address ELECCQ3 of the abnormal address storage area, and the first address ELECCQ4 of the abnormal value storage area, respectively, and clears the R5 register to complete the definition of the storage area and register. After adding one to the R5 count, it is determined whether the R2 pointing value is greater than the critical value; if greater, the R2 pointing value is assigned to the R4 pointing position and the R5 value is assigned to the R3 pointing position, displaying the abnormal address *R3 and the abnormal value *R4, and starting the alarm system 13 at the same time, and pointing R3 and R4 to the next storage unit respectively. If not greater, directly pointing R2 to the next storage unit and then judging whether R5 is equal to 48, and then comparing and analyzing the filtered data in the storage area ELECCQ2 with the critical value. If not equal, then R5 count is increased by one and the critical value is re-judged. If equal, R3 and R4 are pointed to the first address of their respective storage areas, and then it is judged whether *R4 is equal to 0. Then, by judging whether the value pointed to by R4 is 0, the data in the two storage areas are subjected to abnormal detection data analysis and sensor address analysis. If not equal, the abnormal address *R3 and the abnormal value *R4 are cyclically displayed through the PC terminal 11. If equal, the PC terminal 11 displays "None" and returns to the control center program. Find the probe that exceeds the critical value in the storage area ELECCQ2, and use the data in the storage area ELECCQ4 pointed to by R4 and the storage area ELECCQ3 pointed to by R3 as the degree of damage and damage location, and display it in real time through the PC terminal 11. When the critical value is exceeded, the alarm system 13 is turned on to realize the real-time early warning function.

[0039] like Figure 7 As shown, the Hall sensor 6 adopts the F16500 model, including pin 1 for connecting to the power supply, pin 2 for grounding, and pin 3 for output. The sensor circuit includes a capacitor for filtering to make the output voltage more stable, and can transmit AC signals while blocking DC. The specific connection method is: Pin 1 of the F16500 model Hall sensor 6 is connected to the power supply VDD and grounded through a 100nF capacitor C1, pin 2 is grounded, and pin 3 is connected to the output port OUT and grounded through a 100nF capacitor C2.

[0040] like Figure 8As shown, the wave stabilization purification system 7 includes two parts: LM324 chip high-pass filter and LM324 chip low-pass filter. The LM324 operational amplifier is used for signal amplification. The high-pass filter attenuates the signal below the cut-off frequency, which is used to remove low-frequency noise and extract rapidly changing signal components. The low-pass filter attenuates the signal above the cut-off frequency and allows the signal below the cut-off frequency to pass through, which is used to remove high-frequency noise and smooth the signal. The specific connection method is: the positive input end of the LM324 operational amplifier of the high-pass filter is connected to the output end of the Hall sensor 6 through a 100uF capacitor, and the negative input end is grounded through a 62K resistor, and connected to the high-pass filter output end through the LM324 operational amplifier; the positive input end of the LM324 operational amplifier of the low-pass filter is connected to the high-pass filter output end through a 36K resistor, and finally the negative input end of the LM324 operational amplifier is grounded through a 24.7K resistor and a 20K resistor, and the low-pass filter output port is used as the signal output end Vout.

[0041] like Fig. 9 As shown, the photoelectric transmission system 8 includes two parts: the NE555D chip photoelectric transmitting circuit and the LM386M chip photoelectric receiving circuit. The photoelectric transmitting circuit is used to convert the electrical signal into a photoelectric optical signal, and the 8050 transistor is used for signal amplification and circuit control; the photoelectric receiving circuit is used to receive the photoelectric optical signal, convert it into an electrical signal, and then amplify and filter it, and the LM386 power amplifier is used to amplify the low-power signal. The specific connection method is: the photoelectric transmitting circuit is connected to the NE555D chip DISC port through a 10K resistor as the input port Vin, and is connected to the ground through a 0.1uF capacitor, a diode D1 and a resistor R2; the photoelectric receiving circuit is connected to the base of the transistor VT1 through a 100K resistor and a diode D2 through a 0.47uF capacitor, the output port of the LM386M chip 5 is connected to a 10uF capacitor and connected to the IN port of the LM567CH chip, and then connected to the 1K resistor through the 8 port and connected to the base of VT2, and then connected to the output port through the emitter.

[0042] like Fig.10As shown, the digital signal generation and acquisition system 9 includes a CS1232 signal digital conversion chip and a MAX4648 analog multi-way switch. The CS1232 chip is used to convert analog signals into digital signals; the MAX4648 is used to realize the switching of different analog signal sources. The excitation coil 2 is used to establish a magnetic field to ensure the reliable operation of the system. The timing device system 10 is used to provide synchronization signals and control data transmission for the digital system; the PC terminal 11 is used to display the value and position of the final abnormal data; the data security system 14 is used to save data to prevent data loss due to power failure. The specific connection method is: the INT0 port of the STC89S52 chip is connected to the INT port of the CS1232 chip, the P2.0, P2.1, and P2.2 ports are respectively connected to the LBEN, HBEN, and CE ports of the CS1232 chip, and the P1.0, P1.1, and P1.2 ports are respectively connected to the SDI, SDN, and CS ports of the MAX4648 analog multi-way switch; the IN port of the CS1232 chip is connected to the COM port of the MAX4648 analog multi-way switch. The timing device system 10 is connected to the XTAL1 and XTAL2 pins of the STC89S52 microcontroller 14; the PC terminal 11 is connected to the P3.0 and P3.1 pins of the STC89S52 microcontroller 14 through a 232C\422A converter; the CEIE and RST pins of the data security system 14 are connected to the RST and P3.2 pins of the STC89S52 microcontroller 14 accordingly.

[0043] like Fig.11 As shown, the alarm system 13 includes a 9014-type NPN transistor and a buzzer. The transistor is used to amplify the alarm signal, control the on and off of the alarm device, and realize the circuit logic control; the buzzer emits a sound alarm. When the system detects an abnormal or dangerous situation, it drives the buzzer to sound and plays a warning role. The specific connection method is: the positive electrode of the buzzer is connected to the collector of the VT1 transistor and the P3.4 pin of the STC89S52 microcontroller 15, the negative electrode is connected to the collector of the VT2 transistor, the base is connected to the R1 resistor and connected to the VT1 emitter, the resistors R2 and R3 are connected to the VT1 transistor, and the base of VT1 is also connected to the R4 resistor.

[0044] like Fig.12As shown, the auxiliary storage system 12 includes a 74HCT373 latch chip and an IS62WV12816BLL auxiliary storage chip. The 74HCT373 chip is used to store and maintain the input data of the detection system under the control of an enable signal. The IS62WV12816BLL chip is used to meet the needs of storing and processing a large amount of data. The specific connection method is: the P0 port of the STC89S52 chip is connected to the data input port of the 74HCT373 chip respectively, the chip output ports of the 74HCT373 are connected to the address input ports of the IS62WV12816BLL chip respectively, the WR and RD pins of the STC89S52 chip are connected to the WR and OE pins of the IS62WV12816BLL chip respectively, the P2.3, P2.4 and P2.5 ports of the STC89S52 chip are connected to the A10, A9 and A8 address pins of the IS62WV12816BLL chip respectively, and the ALE pin of the STC89S52 chip is connected to the LE pin of the 74HCT373 chip.

[0045] The operation process of the system of the present invention is:

[0046] The detection system generates and collects magnetic flux leakage signals in real time by setting an excitation coil 2 and multiple groups of densely distributed Hall sensors 6 on the surface of the oil and gas pipeline, performs digital filtering processing using a wave stabilization purification system 7, and realizes the digital transformation of analog signals using a digital signal generation and acquisition system 9, so as to realize high-precision, long-term, strong anti-interference real-time fixed-point detection warning and damage location of pipeline defects that need to be detected at fixed points, and realizes the generation and digital collection of magnetic flux leakage signals on the surface of the pipeline that needs to be detected at fixed points using an intelligent hardware system. Write a control center program to detect pipeline defects, call the information collection program to collect the initial magnetic flux leakage signal of the detected pipe section, and use the interference threshold to eliminate interference. Call the signal optimization program for digital calculation and digital filtering processing to realize digital filtering of magnetic flux leakage signals. Call the tangential and normal detection signal processing and analysis program to analyze and process the processed values, use the matrix distribution equation to realize pipeline defect damage detection and damage location, and use the digital magnetic flux leakage signal and system analysis program to realize pipeline surface defect damage assessment and warning. Use the photoelectric transmission system 8 to realize the system remote transmission function, use the timing device system 10 to realize the system time consistency, and use the data security system 14 to realize the system data protection.

[0047] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A fixed-point early warning detection system for leakage magnetic field of oil and gas pipeline defects. The system structure of the present invention includes a hardware control system, an excitation coil, a load-bearing shell, a sliding component, a detector bearing plate, and multiple groups of Hall sensors, wherein the hardware control system is installed between the detector bearing plate and the load-bearing shell; the excitation coil is used to excite the pipeline; the load-bearing shell is used to protect the internal circuit and maintain the stability of the detector; the sliding component is used for installing and removing the detector; the detector bearing plate is composed of packaging materials and a heat sink, and is used to fix multiple groups of Hall sensor detection probes; multiple groups of Hall sensors are used to collect leakage magnetic signals at different test points on the surface of the oil and gas pipeline. This system contains a control center program, which is responsible for the calculation analysis and program call of the whole system; it contains an information collection program, which controls multiple groups of Hall sensors, multiple groups of wave stabilization and purification systems, multiple groups of photoelectric transmission systems, and digital signal generation and acquisition systems to collect, stabilize and purify, photoelectrically transmit and digitally convert the leakage magnetic detection signals on the surface of the oil and gas pipeline; it contains a signal optimization program, which can further digitally filter the collected digital leakage magnetic signals to eliminate interference factors; it contains tangential and normal detection signal processing and analysis programs, which can complete the defect damage degree detection and damage location functions based on the leakage magnetic defect detection characteristics, and use the display function and alarm system of the PC terminal to display, locate and warn the defects and damage of the oil and gas pipeline in real time. The system software sets ELECCQ1 as the leakage magnetic detection data storage area; ELECCQ2 as the filter processing data storage area; ELECCQ3 as the abnormal address storage area; ELECCQ4 as the abnormal value storage area; LINEADR as the critical value comparison unit; The hardware control system includes multiple groups of Hall sensors, multiple groups of wave stabilization purification systems, multiple groups of photoelectric transmission systems, digital signal generation and collection systems, timing device systems, PC terminals, auxiliary storage systems, excitation coils, alarm systems, data security systems, and microcontrollers. Its structural key points are that the output ports of multiple groups of Hall sensor circuits are connected to the input ports of multiple groups of wave stabilization purification systems, and then connected to the input ports of multiple groups of photoelectric transmission systems; the output ports of multiple groups of photoelectric transmission systems are connected to the input ports of digital signal generation and collection systems; the detection signal output ports of digital signal generation and collection systems are connected to the detection signal input ports of microcontrollers; the signal output ports of timing device systems are connected to the signal input ports of microcontrollers; the signal input and output ports of PC terminals are connected to the signal output and input ports of microcontrollers; the storage signal input port of the auxiliary storage system is connected to the storage signal output port of the microcontroller; the excitation coil is connected to the signal output port of the microcontroller; the signal input port of the alarm system is connected to the alarm signal output port of the microcontroller; the signal input port of the data security system is connected to the signal output port of the microcontroller; The control center program first sets system parameters such as acquisition time setting, filter parameter setting and critical value setting, defines ELECCQ1 as the data storage area for leakage detection, and defines ELECCQ2 as the data storage area for filtering processing, completing the system parameter setting and the definition of the storage area. The sensor is defined by the for loop int i=0; i<1; i++ and the N value int N=i, the sensor probe is turned on, and R2 points to the storage area ELECCQ2. The system turns on the Nth probe with printf("The %dth probe has been turned on\n", N), and the N value changes from 1 to 48 cycles with the program, so as to complete the cyclic switching of different probes. The excitation coil is turned on to excite the pipeline, and the information collection program is called. By controlling multiple sets of Hall sensors, multiple sets of wave stabilization purification systems, multiple sets of photoelectric transmission systems, and digital signal generation and acquisition systems, the system functions such as leakage magnetic data acquisition, wave stabilization purification, photoelectric transmission, and signal digital conversion are completed, and the collected and processed digital leakage magnetic signals are stored in the storage area ELECCQ1 to complete the preliminary acquisition of leakage magnetic data. Then call the signal optimization program, and further digitally filter the digital magnetic leakage signal by digitally calculating and processing the benchmark value in the storage area ELECCQ1, and store the filtered detection data in the storage area ELECCQ2 to wait for the system call. Point to the next storage space of the storage area ELECCQ2 through R2, open the next detection probe, and further complete the switching of the magnetic leakage detection probe. Finally, call the tangential and normal detection signal processing and analysis program to locate the damage through the matrix distribution equation, compare the data in the storage area ELECCQ2 with the critical value set in the parameter setting, find the magnetic leakage detection probe that exceeds the critical value, and use the detection data of the storage area ELECCQ3 pointed to by R3 and the storage area ELECCQ4 pointed to by R4 to collect the specific magnetic leakage data and the location of the sensor collected by the detection probe, and display them in real time through the PC terminal, and realize the synchronous warning of abnormal signals through the alarm system, so as to realize defect damage detection, precise positioning and real-time warning; The information collection program first defines the high-intensity interference threshold, the purpose is to eliminate the large external interference, make the collected data more reliable, clear the R5 register, point R1 to the first address ELECCQ1 of the leakage magnetic detection data storage area, and complete the definition of the interference threshold and storage area. Start the IN0 channel, through multiple sets of Hall sensors, multiple sets of wave stabilization purification systems, multiple sets of photoelectric transmission systems, and digital signal generation and collection systems, to collect the leakage magnetic detection signal, wave stabilization purification, photoelectric transmission, and digital conversion of the leakage magnetic signal. Delay waiting for one second to ensure that the leakage magnetic data has completed the digital conversion, and store the converted value in the area pointed to by R1. Compare and analyze the R1 pointing value with the high-intensity interference threshold to determine whether the collected value is greater than the interference threshold. If the collected value is greater than the interference threshold, the collected data is abandoned, the R1 pointing value is set to zero, and the leakage magnetic data is collected again. The IN0 channel is restarted for signal digital conversion. If the collected data is not greater than the interference threshold, the R5 count is increased by one, and the collected digital leakage magnetic signal is judged for the interference threshold, and the collected data that meets the threshold is sent to the storage area ELECCQ1 to achieve the purpose of accurate collection and storage of detection data. Finally, determine whether R5 is 60. If R5 is not 60, point R1 to the next storage unit, re-collect the leakage magnetic data and restart the IN0 channel for signal digital conversion. If R5 is 60, it means that the collection of digital leakage magnetic signals has been completed, and it returns to the control center program. Then, the collected data is subjected to wave stabilization purification, photoelectric transmission, and signal digital conversion to form a digital leakage magnetic signal, and after the interference threshold is judged, it is sent to the leakage magnetic detection storage area ELECCQ1 to wait for the control center program to call; The signal optimization program first clears registers R5, R6, and R7, sets register R8 to 1, defines the maximum number of loops max loop1 and max loop2, and completes the definition of registers and maximum number of loops. Point R1 to the first address ELECCQ1 of the magnetic flux leakage detection storage area, add the value of R7 to R6, and then clear R7. Determine whether the value of R6 is equal to max loop1. If not equal to max loop1, assign the value pointed to by R1 to R5, point R1 to the next storage unit, and count R7 plus one to determine whether R5 is greater than the value pointed to by R1. If greater, swap the two values. If not greater, directly determine whether R7 is equal to max loop2. If not equal to max loop2, select R1 to point to the next storage unit. If equal to max loop2, count R8 plus one and point R1 to the first address of the storage area for the next round of data processing. Through the two cycles of max loop1 and max loop2, the digital magnetic flux leakage signals collected by the storage area ELECCQ1 are arranged in order according to their numerical values. If it is equal to max loop1, R4 and R5 are cleared, R1 is pointed to the 30th value in the storage area, and the value is defined as the reference number B. R1 is then pointed to the first address of the storage area ELECCQ1 for calculation. R4 is added to the value pointed to by R1 and then the reference number B is subtracted. After the R5 count is increased by one, it is determined whether R5 is equal to 60. The sorted digital magnetic leakage signal detection data is processed by digital calculation for the reference value to achieve further digital filtering of the digital magnetic leakage signal. If not equal, R1 is pointed to the next storage unit and recalculated. If equal, the reference number B is added to R4 to obtain the final value of R4 and return to the control center program. The digital magnetic leakage signal in the storage area ELECCQ1 is then further digitally filtered, and after the reference value processing, it is sent to R4 to wait for the system call; The tangential and normal detection signal processing and analysis program first defines the abnormal address storage area ELECCQ3 and the abnormal value storage area ELECCQ4, defines the critical value comparison unit LINEADR, and points the R2, R3, and R4 pointers to the first address ELECCQ2 of the filtering data storage area, the first address ELECCQ3 of the abnormal address storage area, and the first address ELECCQ4 of the abnormal value storage area, respectively, and clears the R5 register to complete the definition of the storage area and register. After adding one to the R5 count, it is determined whether the R2 pointing value is greater than the critical value; if it is greater, the R2 pointing value is assigned to the R4 pointing position and the R5 value is assigned to the R3 pointing position, and the abnormal address *R3 and the abnormal value *R4 are displayed. At the same time, the alarm system is activated, and R3 and R4 are respectively pointed to the next storage unit. If not greater, R2 is directly pointed to the next storage unit and then it is determined whether R5 is equal to 48, and then the filtered data in the storage area ELECCQ2 is compared and analyzed with the critical value. If not equal, then R5 count is increased by one and the critical value is re-judged. If equal, R3 and R4 are pointed to the first address of each storage area, and then it is judged whether *R4 is equal to 0. Then, by judging whether the value pointed to by R4 is 0, the data in the two storage areas are analyzed for abnormal detection data and sensor address. If not equal, the abnormal address *R3 and abnormal value *R4 are cyclically displayed through the PC terminal. If equal, the PC terminal displays "none" and returns to the control center program. Find the probe that exceeds the critical value in the storage area ELECCQ2, and use the data in the storage area ELECCQ4 pointed to by R4 and the storage area ELECCQ3 pointed to by R3 as the damage degree and damage location, and display it in real time through the PC terminal. When the critical value is exceeded, the alarm system is turned on to realize the real-time early warning function.

2. According to claim 1, the oil and gas pipeline defect leakage magnetic fixed-point early warning detection system is characterized in that The Hall sensor of the present invention adopts the F16500 model, including pin 1 for connecting to the power supply, pin 2 for grounding, and pin 3 for output. The sensor circuit includes a capacitor for filtering to make the output voltage more stable, and can transmit AC signals while blocking DC.

3. According to claim 1, the oil and gas pipeline defect leakage magnetic fixed-point early warning detection system is characterized in that The wave stabilization purification system of the present invention comprises two parts: a LM324 chip high-pass filter and a LM324 chip low-pass filter. The LM324 operational amplifier is used for signal amplification. The high-pass filter attenuates signals below the cut-off frequency to remove low-frequency noise and extract rapidly changing signal components. The low-pass filter attenuates signals above the cut-off frequency and allows signals below the cut-off frequency to pass through, to remove high-frequency noise and smooth signals.

4. According to claim 1, the oil and gas pipeline defect leakage magnetic fixed-point early warning detection system is characterized in that The photoelectric transmission system of the present invention comprises two parts: a NE555D chip photoelectric transmitting circuit and a LM386M chip photoelectric receiving circuit. The photoelectric transmitting circuit is used to convert electrical signals into photoelectric optical signals, and the 8050 transistor is used to amplify the signal and control the on / off of the circuit; the photoelectric receiving circuit is used to receive the photoelectric optical signal, convert it into an electrical signal, and then amplify and filter it, and the LM386 power amplifier is used to amplify the low-power signal.

5. According to claim 1, the oil and gas pipeline defect leakage magnetic fixed-point early warning detection system is characterized in that The digital signal generation and acquisition system of the present invention comprises a CS1232 signal digital conversion chip and a MAX4648 analog multi-way switch. The CS1232 chip is used to convert analog signals into digital signals; the MAX4648 is used to switch between different analog signal sources. The excitation coil is used to establish a magnetic field to ensure reliable operation of the system. The timing device system is used to provide synchronization signals and control data transmission for the digital system; the PC terminal is used to display the value and position of the final abnormal data; and the data security system is used to save data to prevent data loss due to power failure.

6. According to claim 1, the oil and gas pipeline defect leakage magnetic fixed-point early warning detection system is characterized in that The alarm system of the present invention comprises a 9014 type NPN transistor and a buzzer. The transistor is used to amplify the alarm signal, control the on and off of the alarm device, and realize circuit logic control; the buzzer emits a sound alarm. When the system detects an abnormal or dangerous situation, the buzzer is driven to sound, which serves as a warning.

7. According to claim 1, the oil and gas pipeline defect leakage magnetic fixed-point early warning detection system is characterized in that The auxiliary storage system of the present invention comprises a 74HCT373 latch chip and an IS62WV12816BLL auxiliary storage chip. The 74HCT373 chip is used to store and maintain the input data of the detection system under the control of an enable signal. The IS62WV12816BLL chip is used to meet the needs of storing and processing a large amount of data.

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