A method and device for protecting metal pipeline from corrosion

Abstract

The present invention discloses a protection method for metal pipeline corrosion prevention, comprising: collecting pipeline voltage and current data; constructing an AC voltage model and a stray current model of the pipeline; determining compensation coupling parameters based on the AC voltage model and the stray current model; converting the compensation coupling parameters into an IGBT gate waveform to control the IGBT to output a compensation voltage. The present invention collects and restores real pipeline voltage and current data, thereby simulating the AC voltage model and the stray current model of the pipeline, and then determining the compensation coupling parameters, thereby achieving precise control of metal pipeline corrosion, and solving the problems of weak protection effect and poor environmental adaptability in traditional metal pipeline protection methods.

Description

Technical Field

[0001] The invention relates to the technical field of metal pipeline protection, and in particular to a protection method and a device for metal pipeline corrosion prevention. Background Art

[0002] The hazards of metal corrosion are enormous, which are manifested in the following ways: 1. The strength of metal structures of bridges and buildings is reduced, causing collapse; 2. Leakage of underground metal pipelines; 3. Damage to the hull of ships; 4. The accuracy and sensitivity of metals and their equipment, instruments and meters are reduced, until an alarming number of them are scrapped.

[0003] In the field of metal corrosion, the corrosion hazards of metal pipelines such as oil and gas pipelines are particularly prominent. The existing pipeline anti-corrosion mainly uses magnesium anodes and constant potentiostats, among which: the magnesium anode mainly sacrifices magnesium to achieve the role of protecting the pipeline, the output voltage of magnesium is constant, and it cannot cope with the loss of the pipeline caused by stray current interference. At the same time, the magnesium anode is a consumable, and replacement requires secondary excavation, which consumes a lot of manpower and material resources; the constant potentiostat maintains a constant voltage or current to achieve the protection of the pipeline from corrosion, but the actual on-site use environment is very complex, and the complexity of the stray current is so high that the constant potentiostat cannot keep up with the speed of change of the stray current. At the same time, the constant potentiostat consumes a lot of electricity and has high requirements for the stability of electricity.

[0004] In summary, traditional metal pipe protection methods have the problems of weak protection effect and poor environmental adaptability. Summary of the invention

[0005] In view of this, the present invention provides a protection method and device for metal pipeline corrosion prevention, which solves the problems of weak protection effect and poor environmental adaptability of traditional metal pipeline protection methods by improving the types of detection data and their corresponding data processing methods.

[0006] To solve the above problems, the technical solution of the present invention is to adopt a protection method for metal pipeline corrosion protection, including: collecting voltage and current data of the pipeline; constructing an AC voltage model and a stray current model of the pipeline; determining compensation coupling parameters based on the AC voltage model and the stray current model; converting the compensation coupling parameters into a gate waveform of the IGBT to control the IGBT output compensation voltage.

[0007] Optionally, collecting the voltage and current data of the pipeline includes: collecting the AC interference voltage data of the pipeline; collecting the DC voltage data of the pipeline; collecting the equivalent AC current component data of the pipeline; and collecting the DC current component data of the pipeline.

[0008] Optionally, constructing the AC voltage model of the pipeline includes: constructing the AC voltage model of the stray voltage based on the AC interference voltage data and the DC voltage data.

[0009] Optionally, constructing the stray current model of the pipeline includes: calculating equivalent resistance data based on the DC voltage data and the DC current component data; and constructing the stray current model based on the AC voltage model and the equivalent resistance data.

[0010] Optionally, compensation coupling parameters are determined based on the AC voltage model and the stray current model, including: extracting the maximum frequency of the stray current and its corresponding minimum governance period based on the stray current model; calculating the compensation voltage based on the AC voltage model and a preset pipeline maintenance voltage; generating governance energy consumption based on the compensation voltage, the stray current model and the minimum governance period; and generating an output duty cycle based on the governance energy consumption and the rated voltage value of the power supply unit.

[0011] Optionally, converting the compensation coupling parameter into a gate waveform of the IGBT includes: determining a peak-to-peak value of the compensation voltage, a voltage curve, and a power on / off time based on the compensation voltage, the stray current model, and the output duty cycle, and outputting the gate waveform of the IGBT.

[0012] Correspondingly, the present invention provides a protective device for metal pipeline corrosion protection, comprising: a potential acquisition unit, used to collect voltage and current data of the pipeline; a stray current control unit, used to construct an AC voltage model and a stray current model of the pipeline, and after determining the compensation coupling parameters based on the AC voltage model and the stray current model, convert the compensation coupling parameters into a gate waveform of the IGBT; an IGBT driving unit, used to output a compensation voltage.

[0013] Optionally, the protection device is also provided with an energy storage unit for supplying power to the device.

[0014] Optionally, the stray current control unit can extract the maximum frequency of the stray current and its corresponding minimum control period based on the stray current model, calculate the compensation voltage based on the AC voltage model and the preset pipeline maintenance voltage, generate the control energy consumption based on the compensation voltage, the stray current model and the minimum control period, and generate the output duty cycle based on the control energy consumption and the rated voltage value of the power supply unit.

[0015] The primary improvement of the present invention is the protection method for metal pipeline corrosion prevention, which collects and restores the real pipeline voltage and current data to simulate the pipeline's AC voltage model and stray current model, and then determines the compensation coupling parameters, thereby achieving precise control of metal pipeline corrosion and solving the problems of weak protection effect and poor environmental adaptability of traditional metal pipeline protection methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1It is a simplified flow chart of the protection method for metal pipeline corrosion protection of the present invention;

[0017] Figure 2 It is a simplified unit connection diagram of the protective device for metal pipeline corrosion protection of the present invention;

[0018] Figure 3 is an example diagram of pipeline voltage before treatment according to the present invention;

[0019] Figure 4 This is an example diagram of pipeline voltage after treatment based on the protection method for metal pipeline corrosion prevention of the present invention. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0021] like Figure 1 As shown, a protection method for metal pipeline corrosion protection includes:

[0022] S1: Collect the voltage and current data of the pipeline.

[0023] Furthermore, collecting the voltage and current data of the pipeline includes: collecting the AC interference voltage data of the pipeline, Among them, V c (t) is the AC component, m is the number of main interference frequencies in the set, A n is the amplitude corresponding to the AC interference of different frequencies, nwt is the angular frequency, θ n is the initial phase angle; collect the DC voltage data V of the pipeline d ; Collect the equivalent AC current component data of the pipeline I c ; Collect the DC current component data I of the pipeline d .

[0024] S2: Construct the AC voltage model and stray current model of the pipeline.

[0025] Further, constructing the AC voltage model of the pipeline includes: constructing the AC voltage model of the stray voltage based on the AC interference voltage data and the DC voltage data, and the expression of the AC voltage model is:

[0026] Furthermore, constructing a stray current model of the pipeline includes: calculating equivalent resistance data based on the DC voltage data and the DC current component data; and constructing the stray current model based on the AC voltage model and the equivalent resistance data.

[0027] Furthermore, the calculation formula for restoring the equivalent resistance data is: Among them, R is the equivalent resistance of the pipeline environment; K is the adjustment coefficient, the default value is 1; V d is the DC voltage data; d is the DC current component data.

[0028] Furthermore, the calculation formula for constructing the stray current model based on the AC voltage model and the equivalent resistance data is:

[0029]

[0030] S3: Determine compensation coupling parameters based on the AC voltage model and the stray current model.

[0031] Furthermore, compensation coupling parameters are determined based on the AC voltage model and the stray current model, including: extracting the maximum frequency of the stray current and its corresponding minimum control period based on the stray current model; calculating the compensation voltage based on the AC voltage model and the preset pipeline maintenance voltage; generating the control energy consumption based on the compensation voltage, the stray current model and the minimum control period; generating the output duty cycle based on the control energy consumption and the rated voltage value of the power supply unit.

[0032] Furthermore, the maximum frequency of the stray current and its corresponding minimum control period are extracted based on the stray current model, including: determining the maximum frequency of the stray current based on the angular frequency of AC interference of different frequencies, and the calculation formula is: f max =nw; then use the formula Calculate the minimum governance period T. The numerical range of T can be: T∈[340ns,∞), because the existing IGBT switching period is 85ns / time, so according to the quarter-cycle compensation principle, the minimum spurious wave period that the protection device can support governance is 340ns, that is, the manageable spurious wave range is (0, 2.9Mhz].

[0033] Furthermore, the calculation formula for calculating the compensation voltage is: V o (t)=V(t)-V T Among them, V T It is the preset pipeline maintenance voltage; since the optimal cathode protection voltage of oil and gas metal pipelines is [-0.85V, -1.75V], the preset pipeline maintenance voltage is usually -1.25V.

[0034] Furthermore, the required governance energy consumption is generated based on the compensation voltage, the stray current model and the minimum governance cycle, including: the formula for calculating the governance energy consumption is: in, x is the number of integer cycles obtained by dividing the data acquisition time t by the minimum cycle T.

[0035] Furthermore, the output duty cycle is generated based on the energy consumption of the control and the rated voltage value U of the power supply unit, including: within the T period, when V o (t) min >0, the power input forward voltage, its output duty cycle is When V o (t) max When <0, the power input reverse voltage, its output duty cycle is

[0036] In the T period,

[0037] V o (t) max >0, V o (t) min When <0, calculate the energy consumed by the forward and reverse output voltages respectively, and the calculation formula is:

[0038] At this time, let Q(x) = |Q(x) + |-|Q(x) - |When Q(x)>0, the output duty cycle is When Q(x)≤0, its output duty cycle is

[0039] S4: converting the compensation coupling parameter into a gate waveform of the IGBT to control the IGBT to output a compensation voltage.

[0040] Furthermore, the compensation coupling parameter is converted into a gate waveform of the IGBT, including: determining the peak-to-peak value of the compensation voltage, the voltage curve, and the power on-off time based on the compensation voltage, the stray current model, and the output duty cycle, and outputting the gate waveform of the IGBT.

[0041] like Figure 3 and Figure 4 As shown, the present invention collects and restores real pipeline voltage and current data to simulate the pipeline's AC voltage model and stray current model, and then determines the compensation coupling parameters, thereby achieving precise control of metal pipeline corrosion and solving the problems of weak protection effect and poor environmental adaptability of traditional metal pipeline protection methods.

[0042] Correspondingly, such as Figure 2As shown, the present invention provides a protective device for metal pipeline corrosion protection, comprising: a potential acquisition unit, used to collect voltage and current data of the pipeline; a stray current control unit, used to construct an AC voltage model and a stray current model of the pipeline, and after determining the compensation coupling parameters based on the AC voltage model and the stray current model, convert the compensation coupling parameters into a gate waveform of an IGBT; an IGBT driving unit, used to output a compensation voltage.

[0043] Furthermore, the protection device is also provided with an energy storage unit for powering the device. Among them, the energy storage unit is composed of natural clean energy such as solar energy and wind energy, and the combination of solar energy and wind energy can provide a set of wind-solar complementary power supply system to power the device without adding external energy consumption. And by combining the treatment energy consumption and output duty cycle calculated by the protection method, the energy storage unit can meet the electric energy required by the protection device while avoiding unnecessary energy waste. Furthermore, the protection device of the present application does not need to be connected to the mains, does not require a large number of manpower to measure the pipeline protection potential data through test piles on a regular basis on site, does not require professional technicians to operate and maintain the equipment, and only needs to install the equipment in the test pile. The power supply comes from natural clean energy such as solar panels and wind power systems. The installation is flexible and convenient, which is convenient for universal deployment.

[0044] Furthermore, the stray current control unit can extract the maximum frequency of the stray current and its corresponding minimum control period based on the stray current model, calculate the compensation voltage based on the AC voltage model and the preset pipeline maintenance voltage, generate the control energy consumption based on the compensation voltage, the stray current model and the minimum control period, and generate the output duty cycle based on the control energy consumption and the rated voltage value of the power supply unit.

[0045] The above is a detailed introduction to a protection method and device for metal pipe corrosion protection provided by an embodiment of the present invention. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can be referenced to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0046] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to the function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention. The steps of the method or algorithm described in conjunction with the embodiments disclosed herein can be directly implemented with a software module executed by a hardware or processor, or a combination of the two. The software module can be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the technical field.

Claims

1. A method for protecting metal pipelines from corrosion, characterized in that: include: Collecting pipeline voltage and current data, including: collecting pipeline AC interference voltage data, collecting pipeline DC voltage data, collecting pipeline equivalent AC current component data, collecting pipeline DC current component data; Construct the AC voltage model and stray current model of the pipeline, The constructing of the AC voltage model of the pipeline includes: constructing the AC voltage model of the stray voltage based on the AC interference voltage data and the DC voltage data, The constructing of the stray current model of the pipeline comprises: calculating equivalent resistance data based on the DC voltage data and the DC current component data, and constructing the stray current model based on the AC voltage model and the equivalent resistance data; Determining compensation coupling parameters based on the AC voltage model and the stray current model, including: extracting the maximum frequency of the stray current and its corresponding minimum governance period based on the stray current model, calculating the compensation voltage based on the AC voltage model and a preset pipeline maintenance voltage, generating governance energy consumption based on the compensation voltage, the stray current model and the minimum governance period, and generating an output duty cycle based on the governance energy consumption and the rated voltage value of the power supply unit; The compensation coupling parameter is converted into a gate waveform of the IGBT to control the IGBT to output a compensation voltage.

2. The protection method according to claim 1, characterized in that: Converting the compensation coupling parameter into a gate waveform of the IGBT includes: The peak-to-peak value of the compensation voltage, the voltage curve, and the power on-off time are determined based on the compensation voltage, the stray current model, and the output duty cycle, and a gate control waveform of the IGBT is output.

3. A protective device for metal pipeline corrosion protection, characterized in that: include: A potential acquisition unit is used to acquire the voltage and current data of the pipeline, including: acquiring the AC interference voltage data of the pipeline, acquiring the DC voltage data of the pipeline, acquiring the equivalent AC current component data of the pipeline, and acquiring the DC current component data of the pipeline; A stray current management unit, used to construct an AC voltage model and a stray current model of the pipeline, and after determining a compensation coupling parameter based on the AC voltage model and the stray current model, convert the compensation coupling parameter into a gate waveform of the IGBT; The constructing of the AC voltage model of the pipeline includes: constructing the AC voltage model of the stray voltage based on the AC interference voltage data and the DC voltage data, The constructing of the stray current model of the pipeline comprises: calculating equivalent resistance data based on the DC voltage data and the DC current component data, and constructing the stray current model based on the AC voltage model and the equivalent resistance data; The compensation coupling parameters include: extracting the maximum frequency of the stray current and its corresponding minimum governance period based on the stray current model, calculating the compensation voltage based on the AC voltage model and the preset pipeline maintenance voltage, generating the governance energy consumption based on the compensation voltage, the stray current model and the minimum governance period, and generating the output duty cycle based on the governance energy consumption and the rated voltage value of the power supply unit; The IGBT driving unit is used for outputting a compensation voltage.

4. The protection device according to claim 3, characterized in that: The protection device is also provided with an energy storage unit for supplying power to the device.

Images