A pipeline corrosion monitoring method, system, electronic device and storage medium

Abstract

The present application relates to a kind of pipeline corrosion monitoring method, belong to dissolved hydrogen monitoring technical field.The method includes: sampling instrument gathers the water sample of the sampling point evenly distributed in pipeline, obtains the real-time dissolved hydrogen concentration of the water sample of adjacent sampling point and obtains the real-time dissolved hydrogen concentration difference of the water sample of adjacent sampling point.Water flow pressure of adjacent sampling point is obtained, and water flow pressure difference of adjacent sampling point is obtained according to water flow pressure of adjacent sampling point.Construction hydrogen leakage diffusion equation obtains hydrogen diffusion flux expression function, and then according to mass conservation law, construction hydrogen leakage concentration calculation model is obtained.According to water flow pressure difference of adjacent sampling point and hydrogen leakage concentration calculation model, the hydrogen leakage concentration of adjacent sampling point is obtained, and the corrosion rate is obtained according to hydrogen leakage concentration.According to corrosion rate and pipeline thickness, establish pipeline corrosion prediction model, monitor the corrosion degree of pipeline.The effect of real-time, accurate monitoring pipeline specific corrosion position and corrosion degree is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of dissolved hydrogen monitoring, and particularly relates to a pipeline corrosion monitoring method and system. BACKGROUND

[0002] The boiler pipeline of a power plant is long-term operated in a harsh working environment of high temperature, high pressure, corrosion and abrasion, and is prone to pipe explosion accidents caused by corrosion, abrasion, oxide skin falling and the like. With the arrival of carbon peak and carbon neutralization, thermal power generating units will become peak-shaving units, and higher requirements are put forward for safe, economic and reliable operation of thermal power plants. How to reduce unplanned shutdown caused by boiler pipeline explosion accidents is a key technical problem to be solved. The method principle of monitoring the boiler pipeline by using a pipeline wall over-temperature and life calculation software is to analyze, process and calculate the real-time operation data of the equipment such as steam flow, temperature, wall temperature of each pipe section, to obtain the current operation condition of the equipment such as over-temperature, pipe life consumption speed, combustion condition in the furnace, and to perform life analysis and diagnosis based on these data. The parameter indexes selected by this method cannot truly reflect the corrosion amount of the boiler pipe, and the monitoring error of the boiler pipeline is large. The monitoring method of the oxide skin thickness model calculates the oxide skin thickness caused by start and stop by accumulating the running time and average temperature, and adds it to the total oxide skin thickness. The disadvantage of this method is that the physical model is not perfect, lacks practicality, and is difficult to meet the requirements of real-time fault monitoring. The analysis method of the corrosion and fouling trend of the thermal equipment based on the monitoring results of chemical parameters such as dissolved oxygen, PH and conductivity changes, and the water vapor quality standard, combined with the scale amount data detected by stopping and cutting the pipe, lacks online monitoring of the corrosion products of the boiler pipeline. The conventional monitoring technology based on dissolved hydrogen calculates the hydrogen leakage amount by the deviation of the dissolved hydrogen concentration at the inlet and outlet of the pipeline, which can only judge the corrosion condition in the entire pipeline, and is difficult to obtain the specific position of the pipeline corrosion. The traditional calculation of hydrogen leakage amount is based on the dissolved hydrogen concentration of the inlet and outlet water samples, and obtains the hydrogen leakage amount in the pipeline through the trace level dissolved hydrogen principle. Since the pipeline is long, other factors are easy to interfere in the middle, and the calculation accuracy is not accurate enough. SUMMARY

[0003] To solve the above problems in the prior art, in a first aspect, the application provides a pipeline corrosion monitoring method, and the specific steps of the method are as follows:

[0004] The sampling instrument collects water samples at uniformly distributed sampling points in the pipeline, gas-liquid separation is performed on the water samples to obtain a target sample, the target sample is sent into a gas chromatograph to obtain the dissolved hydrogen concentration of the water sample, the dissolved hydrogen concentrations of adjacent sampling points are obtained, the dissolved hydrogen concentration is represented by time, the dissolved hydrogen concentration difference of the adjacent sampling points is obtained according to the dissolved hydrogen concentrations of the adjacent sampling points; the water flow pressure of adjacent sampling points and the water flow of adjacent sampling points are obtained, and the water flow pressure difference of adjacent sampling points is obtained according to the water flow pressure of adjacent sampling points;

[0005] A hydrogen leakage diffusion equation is constructed according to the water flow pressure of adjacent sampling points and the dissolved hydrogen concentration of adjacent sampling points, a hydrogen diffusion flux expression function is obtained according to the hydrogen leakage diffusion equation, and a hydrogen leakage concentration calculation model is constructed according to the hydrogen diffusion flux expression function and the law of conservation of mass;

[0006] The hydrogen leakage concentration of adjacent sampling points is obtained according to the water flow pressure difference of adjacent sampling points and the hydrogen leakage concentration calculation model, and the corrosion speed is obtained according to the hydrogen leakage concentration;

[0007] The pipeline corrosion thickness in a set time is calculated according to the pipeline corrosion speed, and the pipeline residual thickness is obtained according to the pipeline corrosion thickness and the pipeline thickness.

[0008] Specifically, the method for obtaining the dissolved hydrogen concentration is that the sampling instrument collects the water samples at uniformly distributed sampling points in the pipeline, the water samples are subjected to rectification to obtain high-boiling-point components and low-boiling-point components of the water samples, the high-boiling-point components are subjected to concentration to obtain the target sample, the target sample is introduced into a gas chromatographic column through a carrier gas for chromatographic monitoring to obtain the plate height of the target sample, and the dissolved hydrogen concentration of the target sample is obtained as the dissolved hydrogen concentration of the water sample according to the plate height.

[0009] Specifically, the step for obtaining the hydrogen diffusion flux is:

[0010] Step 1: a hydrogen leakage diffusion equation is constructed according to the water flow pressure of adjacent sampling points and the dissolved hydrogen concentration difference of adjacent sampling points, and the hydrogen leakage diffusion equation is represented as: Δρ=rTlnC-σV, wherein Δρ represents the dissolved hydrogen concentration difference of adjacent sampling points, r represents a universal hydrogen constant, C represents a hydrogen leakage concentration, V represents a partial molar volume of hydrogen, T represents an absolute temperature, and σ represents the water flow pressure of the first sampling point;

[0011] Step 2: an expression function of diffusion flux is obtained according to the hydrogen leakage diffusion equation, and the expression function of diffusion flux is: wherein D represents a diffusion coefficient of hydrogen, and G represents a diffusion flux.

[0012] Specifically, the hydrogen leakage concentration calculation model construction step is:

[0013] Step one: constructing a mass diffusion equation: wherein v represents the pipe volume of the adjacent sampling point, s represents the pipe area of the adjacent sampling point, and N represents the normal vector of the pipe volume of the adjacent sampling point;

[0014] Step two: constructing the hydrogen concentration calculation model according to the diffusion flux expression function and the mass diffusion equation: wherein θ represents a partial symbol, and Δσ represents the water flow pressure difference of the adjacent sampling point.

[0015] Specifically, the corrosion speed is calculated according to the hydrogen leakage concentration and the corrosion speed calculation formula, and the corrosion speed calculation formula is: wherein V represents the pipe corrosion speed, K represents the corrosion empirical constant, Q represents the water flow, A represents the pipe area, and C represents the hydrogen leakage concentration.

[0016] Specifically, the pipe corrosion thickness is: wherein h represents the pipe corrosion thickness, V represents the corrosion speed, T represents the set time, t represents the unit time, and the pipe residual thickness is obtained by subtracting the pipe corrosion thickness from the pipe thickness.

[0017] In a second aspect, the present application provides a power plant pipe corrosion monitoring system based on dissolved hydrogen monitoring technology, comprising the following modules:

[0018] The data acquisition module, the calculation model construction module, the corrosion speed calculation module, and the corrosion monitoring module;

[0019] The data acquisition module: the sampling instrument collects samples of uniformly distributed sampling points in the pipe, gas-liquid separation is performed on the samples to obtain target samples, the target samples are sent into a gas chromatograph to obtain the dissolved hydrogen concentration of the water sample, the dissolved hydrogen concentration of the adjacent sampling point water sample is obtained, the time representation is given to the dissolved hydrogen concentration, the dissolved hydrogen concentration difference of the adjacent sampling point water sample is obtained according to the dissolved hydrogen concentration of the adjacent sampling point water sample, the adjacent sampling point water flow pressure and the adjacent sampling point water flow are obtained, and the adjacent sampling point water flow pressure difference is obtained according to the adjacent sampling point water flow pressure;

[0020] The calculation model construction module: a hydrogen leakage diffusion equation is constructed according to the adjacent sampling point water flow pressure and the dissolved hydrogen concentration of the adjacent sampling point, a hydrogen diffusion flux expression function is obtained according to the hydrogen leakage diffusion equation, and a hydrogen leakage concentration calculation model is constructed according to the hydrogen diffusion flux expression function and the law of conservation of mass;

[0021] A corrosion rate calculation module: the hydrogen leakage concentration of the adjacent sampling points is calculated according to the adjacent sampling point water flow pressure difference and the hydrogen leakage concentration calculation model, and the corrosion rate is calculated according to the hydrogen leakage concentration;

[0022] A corrosion monitoring module: the pipeline corrosion thickness in the set time is calculated according to the pipeline corrosion rate calculation, and the pipeline residual thickness is calculated according to the pipeline corrosion thickness and the pipeline thickness.

[0023] The beneficial effects of the present application are:

[0024] (1) By uniformly designing sampling points at multiple positions in the pipeline, dynamic data at different positions in the pipeline is obtained, the real-time hydrogen leakage concentration at each position in the pipeline is calculated, and the corrosion amount of the pipeline section is calculated, so that the specific corrosion area position of the pipeline is judged;

[0025] (2) The method of using the constructed hydrogen leakage concentration calculation model, and then calculating the hydrogen leakage concentration according to the dynamic parameters of the hydrogen leakage concentration calculation model to obtain the corrosion rate, can accurately obtain the corrosion condition of the pipeline in real time, and can accurately monitor the corrosion condition of the pipeline in real time. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to facilitate those skilled in the art to understand, the present application will be further described below in combination with the drawings:

[0027] Figure 1 It is a flowchart of a pipeline corrosion monitoring method of the present application. DETAILED DESCRIPTION

[0028] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined application purpose, the specific embodiments, structures, features and effects according to the present application are described in detail below in combination with the drawings and preferred embodiments.

[0029] Please refer to Figure 1 It is a flowchart of a pipeline corrosion monitoring method, which comprises the following steps:

[0030] The sampling instrument is fixedly arranged on the inner wall of the pipeline, the sampling instrument collects water samples of uniformly distributed sampling points in the pipeline, the water samples are subjected to gas-liquid separation to obtain target samples, the target samples are sent into a gas chromatograph to obtain the dissolved hydrogen concentration of the water samples, the dissolved hydrogen concentrations of adjacent sampling points are obtained, the dissolved hydrogen concentration is represented by time, the dissolved hydrogen concentration difference of the adjacent sampling point water samples is obtained according to the dissolved hydrogen concentration of the adjacent sampling point water samples; the water flow pressure of adjacent sampling points and the water flow of adjacent sampling points are obtained, and the water flow pressure difference of adjacent sampling points is obtained according to the water flow pressure of adjacent sampling points;

[0031] constructing a hydrogen leakage diffusion equation according to the water flow pressure of the adjacent sampling point and the dissolved hydrogen concentration of the adjacent sampling point, obtaining a hydrogen diffusion flux expression function according to the hydrogen leakage diffusion equation, and constructing a hydrogen leakage concentration calculation model according to the hydrogen diffusion flux expression function and the law of conservation of mass;

[0032] obtaining the hydrogen leakage concentration of the adjacent sampling point according to the water flow pressure difference of the adjacent sampling point and the hydrogen leakage concentration calculation model, and obtaining the corrosion speed according to the hydrogen leakage concentration;

[0033] calculating the pipeline corrosion thickness in the set time according to the pipeline corrosion speed, and obtaining the pipeline residual thickness according to the pipeline corrosion thickness and the pipeline thickness.

[0034] Specifically, the method for obtaining the dissolved hydrogen concentration is that the sampling instrument collects the water sample at the uniformly distributed sampling points in the pipeline, the water sample is subjected to rectification to obtain high-boiling-point components and low-boiling-point components of the water sample, the high-boiling-point components are subjected to concentration to obtain the target sample, the target sample is subjected to chromatographic monitoring by being introduced into a gas chromatography column through a carrier gas to obtain the plate height of the target sample, and the dissolved hydrogen concentration of the target sample is obtained as the dissolved hydrogen concentration of the water sample according to the plate height.

[0035] Specifically, the step for obtaining the hydrogen diffusion flux is:

[0036] Step 1: constructing a hydrogen leakage diffusion equation according to the water flow pressure of the adjacent sampling point and the dissolved hydrogen concentration difference of the adjacent sampling point, wherein the hydrogen leakage diffusion equation is expressed as: Δρ = rTlnC-σV, wherein Δρ represents the dissolved hydrogen concentration difference of the adjacent sampling point, r represents a general hydrogen constant, C represents a hydrogen leakage concentration, V represents a partial molar volume of hydrogen, T represents an absolute temperature, and σ represents the water flow pressure of the first sampling point.

[0037] Step 2: obtaining an expression function of diffusion flux according to the hydrogen leakage diffusion equation, wherein the expression function of diffusion flux is: wherein D represents a diffusion coefficient of hydrogen, and G represents diffusion flux.

[0038] Specifically, the step for constructing the hydrogen leakage concentration calculation model is:

[0039] Step 1: constructing a mass diffusion equation: wherein v represents the pipeline volume of the adjacent sampling point, s represents the pipeline area of the adjacent sampling point, and N represents a normal vector of the pipeline volume of the adjacent sampling point.

[0040] Step 2: constructing the hydrogen concentration calculation model according to the expression function of diffusion flux and the mass diffusion equation: Wherein, theta represents a bias symbol, and Delta sigma represents a water flow pressure difference of the adjacent sampling points.

[0041] Specifically, the corrosion speed is calculated according to the hydrogen leakage concentration and the corrosion speed calculation formula, and the corrosion speed calculation formula is: Wherein, V represents a pipeline corrosion speed, K represents a corrosion empirical constant, Q represents a water flow, A represents a pipeline area, and C represents the hydrogen leakage concentration.

[0042] Specifically, the pipeline corrosion thickness is: Wherein, h represents the pipeline corrosion thickness, V represents the corrosion speed, T represents the set time, t represents a unit time, and the pipeline residual thickness is obtained by subtracting the pipeline corrosion thickness from the pipeline thickness.

[0043] In a second aspect, the present application provides a power plant pipeline corrosion monitoring system based on dissolved hydrogen monitoring technology, comprising the following modules:

[0044] The data acquisition module, the calculation model construction module, the corrosion speed calculation module, and the corrosion monitoring module.

[0045] The data acquisition module: the sampling instrument collects samples of uniformly distributed sampling points in the pipeline, gas-liquid separation is performed on the samples to obtain target samples, the target samples are sent into a gas chromatograph to obtain the dissolved hydrogen concentration of the water sample, the dissolved hydrogen concentrations of adjacent sampling points are obtained, the time is represented, the dissolved hydrogen concentration difference of the adjacent sampling points is obtained according to the dissolved hydrogen concentrations of the adjacent sampling points, the water flow pressure of the adjacent sampling points and the water flow of the adjacent sampling points are obtained, and the water flow pressure difference of the adjacent sampling points is obtained according to the water flow pressure of the adjacent sampling points.

[0046] The calculation model construction module: a hydrogen leakage diffusion equation is constructed according to the water flow pressure of the adjacent sampling points and the dissolved hydrogen concentration of the adjacent sampling points, a hydrogen diffusion flux expression function is obtained according to the hydrogen leakage diffusion equation, and a hydrogen leakage concentration calculation model is constructed according to the hydrogen diffusion flux expression function and the law of conservation of mass.

[0047] The corrosion speed calculation module: the hydrogen leakage concentration of the adjacent sampling points is obtained according to the water flow pressure difference of the adjacent sampling points and the hydrogen leakage concentration calculation model, and the corrosion speed is obtained according to the hydrogen leakage concentration.

[0048] The corrosion monitoring module: the pipeline corrosion thickness in the set time is calculated according to the pipeline corrosion speed, and the pipeline residual thickness is obtained according to the pipeline corrosion thickness and the pipeline thickness.

[0049] The application further provides an electronic device, comprising a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to realize the method of the application.

[0050] The application further provides a computer readable storage medium, wherein the storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by a processor to realize the method of the application.

[0051] The above is only the preferred embodiment of the application, and does not limit the application in any form. Although the application has been disclosed as above with the preferred embodiment, it is not intended to limit the application. Any person skilled in the art can make slight changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution of the application. Any simple modification, equivalent change and modification of the above embodiments, which does not depart from the technical solution of the application, is still within the scope of the technical solution of the application.

Claims

1. A method of monitoring corrosion in a pipeline, characterized by, The specific steps of the method are: The sampling instrument collects water samples at uniformly distributed sampling points in the pipeline, gas-liquid separation is performed on the water samples to obtain target samples, the target samples are sent into a gas chromatograph to obtain the dissolved hydrogen concentration of the water samples, the dissolved hydrogen concentrations of adjacent sampling points are obtained, time representation is given to the dissolved hydrogen concentrations, the dissolved hydrogen concentration difference of adjacent sampling points is obtained according to the dissolved hydrogen concentrations of the adjacent sampling points; The water flow pressure of adjacent sampling points and the water flow of adjacent sampling points are obtained, and the water flow pressure difference of adjacent sampling points is obtained according to the water flow pressure of adjacent sampling points; A hydrogen leakage diffusion equation is constructed according to the water flow pressure of adjacent sampling points and the dissolved hydrogen concentrations of adjacent sampling points, a hydrogen diffusion flux expression function is obtained according to the hydrogen leakage diffusion equation, and a hydrogen leakage concentration calculation model is constructed according to the hydrogen diffusion flux expression function and the law of conservation of mass; The hydrogen leakage concentration of adjacent sampling points is obtained according to the water flow pressure difference of adjacent sampling points and the hydrogen leakage concentration calculation model, and the corrosion speed is obtained according to the hydrogen leakage concentration. The pipeline corrosion thickness in a set time is calculated according to the pipeline corrosion speed, and the pipeline residual thickness is obtained according to the pipeline corrosion thickness and the pipeline thickness.

2. The method of monitoring corrosion in a pipeline of claim 1, wherein, The method for obtaining the dissolved hydrogen concentration is as follows: the sampling instrument collects the water samples at uniformly distributed sampling points in the pipeline, the water samples are subjected to rectification to obtain high-boiling-point components and low-boiling-point components of the water samples, the high-boiling-point components are concentrated to obtain the target samples, the target samples are introduced into a gas chromatograph column through a carrier gas for chromatographic monitoring to obtain the plate height of the target samples, and the dissolved hydrogen concentration of the target samples is obtained as the dissolved hydrogen concentration of the water samples according to the plate height.

3. The method of monitoring corrosion in a pipeline of claim 1, wherein, The step for obtaining the hydrogen diffusion flux is: Step one: constructing a hydrogen leakage diffusion equation according to the water flow pressure of the adjacent sampling point and the dissolved hydrogen concentration difference of the adjacent sampling point, the hydrogen leakage diffusion equation is expressed as: wherein, the dissolved hydrogen concentration difference of the adjacent sampling point is represented by ΔC, r a general hydrogen gas constant is represented by K, C a hydrogen leakage concentration is represented by C, V a partial molar volume of hydrogen gas is represented by V, T an absolute temperature is represented by T, and a water flow pressure of the first sampling point is represented by σ. Step two: obtaining an expression function of diffusion flux according to the hydrogen leakage diffusion equation, the expression function of diffusion flux is: wherein, D D represents the diffusion coefficient of hydrogen, and G represents the diffusion flux.

4. The method of pipeline corrosion monitoring of claim 3, wherein, The step for constructing the hydrogen leakage concentration calculation model is: Step one: Construct the mass diffusion equation: where, v represents the pipe volume of the adjacent sampling point, s represents the pipe area of the adjacent sampling point, N represents the normal vector of the pipe volume of the adjacent sampling point; Step two: constructing the hydrogen concentration calculation model according to the diffusion flux expression function and the mass diffusion equation: wherein, The sampling instrument is fixedly arranged on the inner wall of the pipeline. denotes a partial division symbol, denotes a water flow pressure difference of the adjacent sampling points.

5. The method of monitoring corrosion in a pipeline of claim 1, wherein, The corrosion speed is calculated according to the hydrogen leakage concentration and the corrosion speed calculation formula, which is: wherein, V represents the pipeline corrosion speed, K represents the corrosion empirical constant, Q represents the water flow, A represents the pipeline area, C represents the hydrogen leakage concentration.

6. The method of monitoring corrosion in a pipeline of claim 1, wherein, The pipe corrosion thickness is: wherein, h represents the pipe corrosion thickness, V represents the corrosion rate, T represents the set time, t represents the unit time, and the pipe thickness minus the pipe corrosion thickness results in the pipe remaining thickness.

7. The method of monitoring corrosion in a pipe of claim 1, wherein, The method comprises the following modules:

8. A pipeline corrosion monitoring system operating using the method of any one of claims 1-7, characterized by, Data acquisition module, calculation model construction module, corrosion speed calculation module, and corrosion monitoring module; The data acquisition module collects samples at uniformly distributed sampling points in the pipeline, gas-liquid separation is performed on the samples to obtain target samples, the target samples are sent into a gas chromatograph to obtain the dissolved hydrogen concentration of the water samples, the dissolved hydrogen concentrations of adjacent sampling points are obtained, time representation is given to the dissolved hydrogen concentrations, the dissolved hydrogen concentration difference of adjacent sampling points is obtained according to the dissolved hydrogen concentrations of the adjacent sampling points, the water flow pressure of adjacent sampling points and the water flow of adjacent sampling points are obtained, and the water flow pressure difference of adjacent sampling points is obtained according to the water flow pressure of adjacent sampling points; The calculation model construction module constructs a hydrogen leakage diffusion equation according to the water flow pressure of adjacent sampling points and the dissolved hydrogen concentrations of adjacent sampling points, obtains a hydrogen diffusion flux expression function according to the hydrogen leakage diffusion equation, and constructs a hydrogen leakage concentration calculation model according to the hydrogen diffusion flux expression function and the law of conservation of mass; The corrosion speed calculation module obtains the hydrogen leakage concentration of adjacent sampling points according to the water flow pressure difference of adjacent sampling points and the hydrogen leakage concentration calculation model, and obtains the corrosion speed according to the hydrogen leakage concentration. ​ The corrosion monitoring module calculates the pipeline corrosion thickness in the set time according to the pipeline corrosion speed, and obtains the pipeline residual thickness according to the pipeline corrosion thickness and the pipeline thickness.

9. An electronic device, comprising: The electronic device includes a processor and a memory, and the memory stores at least one instruction, at least one program, a code set or an instruction set, which is loaded and executed by the processor to implement the method of any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The storage medium stores at least one instruction, at least one program, a code set or an instruction set, which is loaded and executed by the processor to implement the method of any one of claims 1-7.

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