Device for simulating flowing of corrosion inhibitor in pipeline and corrosion inhibitor effect evaluation method

Abstract

The invention discloses a device for simulating flowing of a corrosion inhibitor in a pipeline and a corrosion inhibitor effect evaluation method, the device comprises a corrosion inhibitor filling cabin, a corrosion inhibitor experiment cabin and acquisition equipment, and is used for experimenting and acquiring data required by the evaluation method, and the evaluation method comprises the following steps: acquiring evaluation index data of a corrosion inhibitor to be tested; inputting the evaluation index data into a preset evaluation model, and obtaining a comprehensive evaluation score output by the preset evaluation model; and determining an evaluation grade corresponding to the comprehensive evaluation score in the target preset score interval, and outputting the comprehensive evaluation score and the evaluation grade of the corrosion inhibitor to be tested. The device adopts a modularly-designed pipe diameter-variable simulation pipeline assembly, and can realize multi-condition simulation such as adjustable injection points and various corrosion inhibitor injection modes. According to the effect evaluation method, a mode of combining an analytic hierarchy process and a fuzzy comprehensive evaluation method is adopted, multi-dimensional and complex data is converted into visual and practical evaluation, and quantitative evaluation of the corrosion inhibition effect is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of corrosion inhibitors, and particularly relates to a device for simulating the flow of a corrosion inhibitor in a pipeline and a method for evaluating the effect of the corrosion inhibitor. BACKGROUND

[0002] In the field of industrial production, pipelines are key carriers for transporting various media, and the corrosion problem thereof is always a major challenge to production safety and efficiency. Corrosion inhibitors have become a widely used protective means due to their significant effect in inhibiting pipeline corrosion.

[0003] In actual industrial scenarios, the medium in the pipeline is relatively complex, including solutions with different concentrations of salt, liquids with different pH values, and multiphase mixed media. Existing simulation devices can only carry out experiments on single and relatively pure media, and are difficult to simulate the above-mentioned complex medium environment, resulting in that the flow state and effect of the corrosion inhibitor in the real complex medium cannot be effectively studied. Moreover, the operating conditions of industrial pipelines cover extreme conditions such as high temperature, high pressure and high flow rate. When facing different operating conditions, the selection and use of the corrosion inhibitor are based on experimental data. At the same time, the pipe diameters of actual industrial pipelines are numerous, and different pipe diameters will result in significant differences in the flow state, flow velocity distribution and diffusion path of the corrosion inhibitor in the pipeline. However, the pipe diameters of existing simulation devices are mostly fixed and cannot be flexibly adjusted to meet the actual needs of different pipe diameters, which makes the experimental results deviate greatly from the real industrial scenarios.

[0004] The evaluation of the use effect of the corrosion inhibitor relies on artificial observation for rough evaluation or the weight loss method. The former is highly subjective, difficult to fully consider factors and lacks quantitative basis, and when testing multiple corrosion inhibitors or evaluating a large number of equipment, the efficiency is extremely low. The latter can only obtain the average corrosion rate in a period of time and cannot reflect the effect of the corrosion inhibitor at different times in real time. For local corrosion in the corrosion process, such as pitting, the overall mass change may not be obvious, which may not be accurately detected, resulting in misjudgment of the actual protection ability of the corrosion inhibitor. SUMMARY

[0005] In view of the above problems existing in the prior art, the application provides a device for simulating the flow of a corrosion inhibitor in a pipeline and a method for evaluating the effect of the corrosion inhibitor, which includes a device for simulating the flow state of the corrosion inhibitor under pipeline flow conditions and a method for quantitatively evaluating the effect of the corrosion inhibitor, which can be used for different media, operating conditions and variable pipe diameters.

[0006] To achieve the above-mentioned purpose, the first aspect of the application provides a device for simulating the flow of a corrosion inhibitor in a pipeline, which includes:

[0007] The corrosion inhibitor filling cabin is connected to the experimental loop through the filling cabin reducing joint at both ends, and the corrosion inhibitor experimental cabin is located at the output side of the corrosion inhibitor filling cabin.

[0008] The corrosion inhibitor experimental cabin is connected to the experimental loop through the filling cabin reducing joint at both ends, and the corrosion inhibitor experimental cabin is located at the output side of the corrosion inhibitor filling cabin.

[0009] The collection device includes an image collection device, a flow rate sensor, and a pressure sensor.

[0010] The corrosion inhibitor filling device includes a timing automatic electric control device, a corrosion inhibitor feeding device, a corrosion inhibitor pushing sealing piston, and a corrosion inhibitor storage cabin connected in sequence from top to bottom.

[0011] The device for simulating the flow of corrosion inhibitors in the pipeline is made of transparent material for easy flow observation.

[0012] The second aspect of the present application provides a corrosion inhibitor effect evaluation method applied to the device for simulating the flow of corrosion inhibitors in the pipeline.

[0013] The evaluation index data of the to-be-tested corrosion inhibitor is obtained, including the corrosion rate, pre-film resistance, pre-film capacitance, coverage rate, thickness distribution, continuity, flow rate, pressure, accumulation state, and corrosion speed change data of the to-be-tested corrosion inhibitor.

[0014] The evaluation index data is input into a preset evaluation model to obtain a comprehensive evaluation score output by the preset evaluation model.

[0015] The comprehensive evaluation score is determined in the target preset score interval to obtain the comprehensive evaluation score and the evaluation level of the to-be-tested corrosion inhibitor.

[0016] The analytic hierarchy process confirms the index weight, including the following steps:

[0017] Based on the importance of the effect of the inhibitor, the evaluation index data is constructed into a judgment matrix;

[0018] The maximum eigenvalue of the judgment matrix and its corresponding eigenvector are calculated, and the eigenvector is normalized to obtain the weight vector of each index;

[0019] The judgment matrix is subjected to consistency check to determine the validity of the weight vector.

[0020] The judgment matrix compares the evaluation index data in pairs and scales, and 1-9 and its inverse are used to represent the results of the pairwise comparison, wherein 1 indicates that the two factors have equal importance; 3 indicates that one factor is slightly more important than the other; 5 indicates that one factor is obviously more important than the other; 7 indicates that one factor is strongly more important than the other; 9 indicates that one factor is extremely more important than the other; 2, 4, 6, and 8 are intermediate values between the above judgments, and finally a 10x10 judgment matrix is constructed.

[0021] The fuzzy comprehensive evaluation method includes the following steps for calculating the quantitative score:

[0022] Determine the evaluation factor set corresponding to the evaluation index data and the comment set corresponding to the evaluation level;

[0023] Determine the membership degree of the evaluation index data to each level of the comment set by expert scoring, and construct a fuzzy relationship matrix;

[0024] The fuzzy synthetic weight vector and the fuzzy relationship matrix obtain a comprehensive evaluation vector;

[0025] The weighted average method is used to calculate the quantitative score.

[0026] The evaluation level includes four levels corresponding to the effect of the inhibitor, including excellent, good, general, and poor, excellent level is 85-100 points, good is 70-84 points, general is 60-69 points, and poor is less than 60 points.

[0027] The beneficial effects of the present application are:

[0028] The application provides a device for simulating the flow of corrosion inhibitor in a pipeline and a corrosion inhibitor effect evaluation method. The device adopts a variable-diameter simulation pipeline assembly designed in a modular manner, and through a quick connection device, different-diameter simulation pipelines can be quickly assembled. The flow state of the corrosion inhibitor in different-diameter industrial pipelines can be simulated, the consistency of the experimental results and the actual industrial scene is effectively improved, reliable references for the application of corrosion inhibitors to pipelines of various diameters are provided, and the deficiencies of the prior art in the simulation of pipeline diameters are effectively made up. The device provides relatively comprehensive simulation conditions, and can realize the simulation of multiple conditions such as adjustable injection points and multiple corrosion inhibitor injection modes. The effect evaluation method combines the analytic hierarchy process and the fuzzy comprehensive evaluation method, converts multi-dimensional and complex data into intuitive and practically meaningful evaluations, realizes quantitative evaluation of the corrosion effect, and provides strong support for the scientific selection and optimized use of corrosion inhibitors in industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A structure diagram of the device for simulating the flow of corrosion inhibitor in a pipeline shown in embodiment one;

[0030] Figure 2 A structure diagram of an experimental cabin variable-diameter module and an experimental cabin experimental pipe of the device for simulating the flow of corrosion inhibitor in a pipeline shown in embodiment one;

[0031] Figure 3 A structure diagram of a corrosion inhibitor injection device of the device for simulating the flow of corrosion inhibitor in a pipeline shown in embodiment one;

[0032] Figure 4 A flowchart of the corrosion inhibitor effect evaluation method shown in embodiment two;

[0033] In the figure, 1 is an experimental loop external pipe, 2 is an injection cabin variable-diameter joint, 3 is a corrosion inhibitor injection cabin, 4 is an injection cabin sensor reserved hole, 5 is an experimental injection guide pipe, 6 is an experimental cabin variable-diameter joint, 7 is a corrosion inhibitor experimental cabin, 8 is an experimental cabin variable-diameter module, 9 is an experimental cabin experimental pipe, 10 is a test piece electrochemical external interface, 11 is a timing automatic electric control device, 12 is a corrosion inhibitor feeding device, 13 is a corrosion inhibitor propelling sealing piston, 14 is an injection corrosion inhibitor storage cabin, and 15 is an image acquisition equipment. DETAILED DESCRIPTION

[0034] The embodiments of the application will be described in more detail with reference to the drawings. Although the embodiments of the application are shown in the drawings, it should be understood that the application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the application more thorough and complete, and to fully convey the scope of the application to those skilled in the art.

[0035] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0037] Unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they may refer to fixed or detachable connections, or integration; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0038] Example 1:

[0039] like Figure 1 The device shown is a device for simulating the flow of corrosion inhibitor in a pipeline. To facilitate flow observation, the device is made of transparent material. It can simulate the flow of corrosion inhibitor in a pipeline with variable pipe diameter and working conditions. The corrosion inhibitor filling form, the corrosion inhibitor flow state and the effect of the filling position can be studied. It includes: a corrosion inhibitor filling chamber 3, a corrosion inhibitor experimental chamber 7 and collection equipment.

[0040] Both ends of the corrosion inhibitor filling chamber 3 are connected to the experimental loop through the filling chamber reducer 2. The experimental injection conduit 5 is inserted and installed in the corrosion inhibitor filling chamber 3. The input end of the experimental injection conduit 5 is connected to the corrosion inhibitor filling device used to fill the experimental injection conduit 5. The corrosion inhibitor filling amount, filling position and filling form are controlled by the experimental injection conduit 5 and the corrosion inhibitor filling device to simulate corrosion inhibitor filling under different forms.

[0041] The inhibitor filling device comprises a timing automatic electric control device 11, an inhibitor feeding device 12, an inhibitor pushing and sealing piston 13 and an inhibitor filling storage cabin 14. During the experiment, the lower end outlet of the inhibitor filling storage cabin 14 is directly connected with the experimental injection conduit 5 or connected through a hose; the inhibitor to be studied is added into the inhibitor filling storage cabin 14 according to the injection amount, and the cabin wall has a scale to control the amount; the device is connected and sealed, the timing automatic electric control device 11 is connected with a power supply, and continuous filling or intermittent filling is set according to the injection mode, the mechanism of the inhibitor feeding device 12 is controlled according to the setting of the electric control device, the inhibitor pushing and sealing piston 13 is pushed to fill the inhibitor into the experimental cabin. Figure 3

[0042] The inhibitor experimental cabin 7 is connected with the experimental loop through the filling cabin reducing joint 2 at both ends, and the inhibitor experimental cabin 7 is located at the output side of the inhibitor filling cabin 3. The inhibitor flows into the inhibitor experimental cabin 7 along the inhibitor filling cabin 3 and the experimental loop external pipe 1. The length of the experimental loop external pipe 1 between the inhibitor experimental cabin 7 and the inhibitor filling cabin 3 is determined according to the distance from the inhibitor filling to the test piece distance for testing the inhibitor effect.

[0043] The inhibitor experimental cabin 7 is installed with an experimental cabin experimental pipe 9 for observing the adhesion state of the inhibitor and the metal corrosion research. The experimental cabin experimental pipe 9 is a semi-annular pipe, as shown in Figure 2 The experimental cabin experimental pipe 9 is installed in the inhibitor experimental cabin 7 through the matching experimental cabin reducing module 8 and realizes reducing. The experimental cabin experimental pipe 9 is connected with the test piece electrochemical external interface 10 based on a wire. The test piece electrochemical external interface 10 is connected with a conductive testing instrument or an electrochemical workstation to collect data.

[0044] The collection equipment comprises an image collection equipment 15, a flow rate sensor and a pressure sensor. The image collection equipment 15 is installed on the upper side of the inhibitor filling cabin 3 and the inhibitor experimental cabin 7, respectively. The flow rate sensor and the pressure sensor are installed in the inhibitor experimental cabin 7.

[0045] Before the experiment, the inhibitor filling cabin 3 is connected with the existing experimental loop external pipe 1 of the experimental loop through the filling cabin reducing joint 2. The experimental loop external pipe 1 of the input end of the experimental cabin reducing joint 6 is also connected through the filling cabin reducing joint 2. The experimental cabin reducing joint 6 is used to connect at both ends of the inhibitor experimental cabin 7 and connect with the experimental loop. The wall surface of the filling cabin reducing joint 2 is conical, the sizes of the flanges at both ends are different, the reducing is realized, and the reducing size is determined according to the sizes of the experimental loop and the experimental cabin.

[0046] ​During the experiment, the sensors are installed through the reserved holes 4 of the injection cabin sensors to collect data of the corrosion inhibitor flow rate, pressure and the like during the experiment. The injection amount, injection position and injection form of the corrosion inhibitor are controlled by adjusting the experimental injection conduit 5 to simulate the corrosion inhibitor injection under different forms. Specifically, the position of the outlet of the experimental injection conduit 5 in the pipe is adjusted, the experimental injection conduit 5 is moved up and down to adjust the position of the injection port, the injection amount and time are controlled by controlling the experimental injection conduit 5, and the injection form is mainly continuous injection and intermittent injection.

[0047] The image acquisition device 15 is used to capture the movement state of the corrosion inhibitor outside the corrosion inhibitor injection cabin 3. According to the experimental requirements, the same metal material as the target pipeline is selected to process the semi-annular pipe section to process the experimental cabin experimental pipe 9, which is used to observe the adhesion state of the corrosion inhibitor and can also be used for metal corrosion research. The corrosion monitoring is tested by connecting the equipment through the test piece electrochemical external interface 10 during the experiment. The experimental cabin variable diameter module 8 is selected according to the pipe diameter requirement, and the experimental cabin variable diameter module 8 is used to cooperate with the experimental cabin experimental pipe 9 for installation. The experimental cabin variable diameter module 8 has the same size as the experimental cabin experimental pipe 9 and is made of non-metallic material. The combination is a whole cylindrical pipe installed in the corrosion inhibitor experimental cabin 7.

[0048] The corrosion inhibitor test includes: connecting the experimental loop according to the experimental requirements, connecting the corrosion inhibitor experimental section to the experimental loop, controlling the pressure, flow rate, temperature and the like according to the experimental requirements, and running the flow medium experimental loop. The test piece electrochemical external interface 10 is connected to the electrochemical workstation, the injection amount and injection form (continuous, intermittent) are controlled through the corrosion inhibitor injection port during the test to simulate the corrosion inhibitor injection form, the corrosion rate of the experimental pipe before and after the corrosion inhibitor injection is evaluated to evaluate the effect of the corrosion inhibitor; the test piece electrochemical external interface 10 is connected to the conductive test instrument to test the pre-film condition of the corrosion inhibitor on the surface of the experimental pipe; the image acquisition device 15 is used to capture the distribution and adhesion state of the corrosion inhibitor on the surface of the experimental pipe, the contact dynamic characteristics, the position in the pipe, the flow rate, the accumulation and the like to evaluate the effect of the corrosion inhibitor. During the experiment, the corrosion inhibitor is dyed or fluorescently labeled, and the image data is captured by color or fluorescent agent during sampling. The corrosion resistance of the corrosion inhibitor is tested by running the experimental loop for a long time. The corrosion rate under the action of the corrosion inhibitor without the corrosion inhibitor, different corrosion inhibitor states and different components is compared.

[0049] Example Two:

[0050] As shown in Figure 4 A method for evaluating the effect of a corrosion inhibitor flowing in a simulated pipeline, which is applicable to the device for simulating the flow of a corrosion inhibitor in a pipeline as shown in Example One, comprises the following steps:

[0051] S1, obtaining evaluation index data of the to-be-tested corrosion inhibitor. The evaluation index data includes corrosion rate, pre-film resistance, pre-film capacitance, coverage rate, thickness distribution, continuity, flow rate, pressure, accumulation state and corrosion rate change data of the to-be-tested corrosion inhibitor.

[0052] The corrosion rate is collected by setting an electrochemical external interface on the test piece in the corrosion inhibitor test cabin and connecting an external electrochemical workstation. The electrochemical workstation can monitor the corrosion potential and polarization resistance of the experimental pipe before and after the corrosion inhibitor is filled in real time. According to the Stern-Geary formula, the polarization resistance R P , the corrosion rate can be calculated according to formula (1):

[0053]

[0054] In the formula, B is a constant related to the metal material and the corrosion environment. Since this index reflects the corrosion of the experimental pipe under the action of the corrosion inhibitor, the detection equipment is set in the corrosion inhibitor test cabin, and the parameters of the corrosion reaction site can be directly monitored.

[0055] Pre-film resistance and pre-film capacitance: The electrochemical external interface of the test piece in the corrosion inhibitor test cabin is connected to an external conductive testing instrument to measure. For pre-film resistance, a certain frequency of electrical signal is applied to measure the pre-film resistance formed by the corrosion inhibitor on the surface of the experimental pipe, which reflects the integrity and density of the pre-film. The pre-film capacitance measurement selects equipment such as a high-precision and wide-range capacitance measuring instrument device. The detection equipment of these two indexes is set in the corrosion inhibitor test cabin, because the pre-film is formed on the surface of the experimental pipe, and the accurate pre-film electrical parameters can be directly obtained by measuring here.

[0056] Coverage rate, thickness distribution and continuity: A high-speed camera is used to collect data with a transparent material made experimental cabin and experimental cabin variable diameter module. In order to make the distribution state of the corrosion inhibitor more easily observed, the corrosion inhibitor is dyed or fluorescently labeled during the experiment. The high-speed camera captures images of the distribution and adhesion state of the corrosion inhibitor on the surface of the experimental pipe through the transparent cabin body, and then uses image recognition algorithm to identify the pixel ratio of the corrosion inhibitor coverage area to calculate the coverage rate by means of image processing technology; the thickness distribution is estimated by analyzing the gray value difference of the corrosion inhibitor images at different positions; the continuity is judged according to the continuity of the corrosion inhibitor profile in the image. Since these indexes focus on the distribution characteristics of the corrosion inhibitor on the surface of the experimental pipe, the high-speed camera is set in the corrosion inhibitor test cabin, which can clearly capture the state of the interaction between the corrosion inhibitor and the pipe surface.

[0057] Flow rate, pressure: install flow rate sensor and pressure sensor in the transparent inhibitor test cabin. The flow rate sensor can use an electromagnetic flow rate sensor to determine the flow rate of the inhibitor in the pipe by measuring the induced electromotive force generated by the fluid cutting magnetic induction lines; the pressure sensor can use a strain gauge pressure sensor to measure the pressure value based on the change of the resistance of the strain gauge under pressure.

[0058] Accumulation state: take a video of the contact dynamic characteristics of the inhibitor and the wall surface by a high-speed camera, and analyze whether there is an accumulation phenomenon of the inhibitor in the pipeline.

[0059] Corrosion rate change data: set and measure the same electrochemical workstation and related interface as the corrosion rate at the experimental pipe in the long-term running experimental loop. Collect the corrosion rate data of the experimental pipe regularly, and compare the corrosion rate changes under the conditions of no inhibitor, different inhibitor states (such as different concentrations, different filling forms), and different component inhibitors. Since this index focuses on the effect change of the inhibitor in the long-term actual operation, the electrochemical workstation needs to be continuously monitored at this place, and complete long-term corrosion rate change data can be obtained.

[0060] S2, input the evaluation index data into the preset evaluation model to obtain the comprehensive evaluation score output by the preset evaluation model. The preset evaluation model is an analytic hierarchy process for determining the index weight of the evaluation index data, a fuzzy comprehensive evaluation method for quantifying the index weight, and a neural network model used as a synthesis model.

[0061] The preset evaluation model adopts a multilayer perceptron neural network model. The input layer of the model receives various types of data collected above, including corrosion rate, pre-film condition parameters, inhibitor distribution characteristic parameters, flow state parameters, and long-term running corrosion rate change data. The hidden layer performs nonlinear transformation and feature extraction on the input data through multiple neurons to mine the potential relationship between the data. The output layer outputs the inhibitor effect evaluation result in the form of a quantitative score.

[0062] Confirming the index weight based on the analytic hierarchy process includes the following steps:

[0063] S211, based on the importance of the effect of the inhibitor, the evaluation index data is constructed into a judgment matrix. The corrosion rate, pre-film condition parameters (pre-film resistance, capacitance), inhibitor distribution characteristic parameters (coverage rate, thickness distribution, continuity), flow state parameters (flow rate, pressure, accumulation state), and long-term running corrosion rate change data indicators are compared according to the importance of the effect of the inhibitor, and a judgment matrix is constructed.

[0064] The judgment matrix compares and scales the evaluation index data pairwise, and uses 1-9 and their reciprocals to represent the results of pairwise comparison, wherein 1 represents that two factors have equal importance; 3 represents that one factor is slightly more important than the other factor; 5 represents that one factor is obviously more important than the other factor; 7 represents that one factor is strongly more important than the other factor; 9 represents that one factor is extremely more important than the other factor; 2, 4, 6 and 8 are intermediate values between the above judgments, and finally a 10x10 judgment matrix is constructed.

[0065] Taking the corrosion rate as an example, the corrosion rate is a key indicator for directly measuring the effect of corrosion inhibitor on inhibiting metal corrosion, and has a significant impact on the corrosion inhibition effect. Compared with the pre-film resistance, the change of the corrosion rate has a more significant impact on the corrosion inhibition effect, so a 12 = 3, a 21 = 1 / 3; compared with the pre-film capacitance, the corrosion rate has a more significant impact, so a 13 = 4, a 31 = 1 / 4. Considering that the coverage rate mainly affects the coverage range of the corrosion inhibitor on the metal surface, and the corrosion rate is directly related to the metal corrosion process, the corrosion rate has a greater impact, so a 14 = 5, a 41 = 1 / 5. Similarly, when comparing with the thickness distribution, continuity, flow rate, pressure, accumulation state and corrosion speed change data of long-term operation, according to the relative degree of influence on the corrosion inhibition effect, it is determined that:

[0066] a 15 = 4, a 16 = 5, a 17 = 6, a 18 = 5, a 19 = 5, a 1,10 = 5.

[0067] By analogy, the 10x10 judgment matrix A constructed in combination is as follows:

[0068]

[0069] S212, the maximum eigenvalue of the judgment matrix and the corresponding eigenvector are calculated, and the eigenvector is normalized to obtain the weight vector of each index. The maximum eigenvalue λ max of the judgment matrix A and the corresponding eigenvector W are calculated by using the power method.

[0070] An initial vector X0 is randomly selected, and each element of the vector is normalized by taking the square root of the sum of squares of the elements.

[0071] X0 = (0.3, 0.2, 0.1, 0.1, 0.1, 0.05, 0.05, 0.05, 0.05, 0.05) T ;

[0072] Through iterative calculation by formula (2), after multiple iterations (for example, 50 times) until ||X k+1 -X k ||<10 -6 The final feature vector W is obtained.

[0073]

[0074] W=(0.32,0.18,0.12,0.07,0.12,0.07,0.04,0.07,0.07,0.07) T ;

[0075] The maximum eigenvalue is:

[0076]

[0077] The feature vector W is normalized to obtain the weight vector w:

[0078] w=(0.32,0.18,0.12,0.07,0.12,0.07,0.04,0.07,0.07,0.07) T .

[0079] S213, consistency check is performed on the judgment matrix to determine the validity of the weight vector.

[0080] The consistency index CI=(λ max -10) / (10-1)≈0.048, and when n=10, the random consistency index RI=1.49 is obtained by looking up the table, and the consistency ratio CR=CI / RI≈0.032<0.1 is calculated, indicating that the judgment matrix is acceptable in terms of consistency, and the weight vector is valid.

[0081] The following steps are included in the calculation of the quantitative score based on the fuzzy comprehensive evaluation method:

[0082] S221, determine the evaluation factor set corresponding to the evaluation index data and the comment set corresponding to the evaluation level;

[0083] The evaluation level includes four levels corresponding to the effect of the corrosion inhibitor, including excellent, good, general and poor, and the comment set V={v1, v2, v3, v4} is established, v1 is excellent (85-100 points), v2 is good (70-84 points), v3 is general (60-69 points), and v4 is poor (less than 60 points).

[0084] S222, determine the membership degree of the evaluation index data to each level of the comment set by expert scoring, and construct a fuzzy relationship matrix.

[0085] Through statistical analysis of a large number of experimental data and combined with the evaluation of many industry experts, the membership degree of each index to each level in the evaluation set is determined, and a fuzzy relation matrix R is constructed:

[0086]

[0087] Experimental data is an important basis for membership degree. If a series of experiments are carried out, such as measuring the corrosion rate, coverage rate and other index data after the action of the corrosion inhibitor under different temperature, pressure, flow rate and other working conditions. Compare these data with the corresponding range of the pre-set excellent, good, general and poor four levels, so as to determine the membership degree of the corrosion inhibitor to each level under different indexes. For example, in 50 different working condition experiments, if the corrosion rate of 15 experimental data corresponds to the excellent level range, then from the experimental data point of view, the membership degree of the corrosion rate index to the excellent level is initially considered to be 15÷50=0.3. For some cases that are difficult to accurately determine the membership degree by relying on experimental data alone, such as the continuity of the pipe wall covered by the corrosion inhibitor under complex flow state, the integrity of the pre-film, experts can make judgments and corrections on the membership degree based on their past experience and understanding of the action mechanism of the corrosion inhibitor. Finally, the experimental data and expert experience are combined to form a relatively accurate membership degree, and then the fuzzy relation matrix is constructed.

[0088] S223, the fuzzy synthetic weight vector and the fuzzy relation matrix obtain a comprehensive evaluation vector.

[0089] The weight vector w is fuzzy synthesized with the fuzzy relation matrix R to obtain a comprehensive evaluation vector B=w T R.

[0090] S224, a quantitative score S is calculated by using the weighted average method.

[0091] Wherein, S is calculated by formula (3), and formula (3) is:

[0092]

[0093] Wherein, c j Is the middle value of each level in the evaluation set V, c1=92.5, c2=77, c3,64.5, c4=50, S=75.3.

[0094] S3, determine the evaluation level corresponding to the target preset score interval of the comprehensive evaluation score, and output the comprehensive evaluation score and the evaluation level of the tested corrosion inhibitor.

[0095] According to the grading standard, 75.3 corresponds to the level v2 (70-84 points), and the comprehensive evaluation score of the tested corrosion inhibitor is 75.3 points, and the evaluation level is good level.

[0096] Finally, it should be noted that the terms "first" and "second", and the like, are used herein only to distinguish one identification entity from another, and do not require or imply these entities to be present in any particular relationship or order. Also, the terms "comprising", "including", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0097] The units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, i.e. can be located in one place, or can be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0098] The above has described the embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles, practical application or improvement of the technology in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A device for simulating the flow of corrosion inhibitor in a pipeline, characterized in that: include: A corrosion inhibitor filling chamber, wherein both ends of the corrosion inhibitor filling chamber are connected to the experimental loop via a filling chamber reducer; an experimental injection conduit and a corrosion inhibitor filling device connected to the input end of the experimental injection conduit for filling the experimental injection conduit are inserted into the corrosion inhibitor filling chamber; the corrosion inhibitor filling amount, filling position, and filling form are controlled by the experimental injection conduit and the corrosion inhibitor filling device to simulate corrosion inhibitor filling in different forms; A corrosion inhibitor experimental chamber, wherein both ends of the corrosion inhibitor experimental chamber are connected to the experimental loop through a filling chamber reducer, and the corrosion inhibitor experimental chamber is located at the output side of the corrosion inhibitor filling chamber. The corrosion inhibitor experimental chamber is equipped with an experimental chamber experimental pipe fitting for observing the adhesion state of the corrosion inhibitor and metal corrosion research. The experimental chamber experimental pipe fitting is a semi-annular pipe fitting, which is installed in the corrosion inhibitor experimental chamber and changes its diameter through a matching experimental chamber reducer module. The experimental chamber experimental pipe fitting is connected to the electrochemical external interface of the specimen based on a wire, and the electrochemical external interface of the specimen is connected to an external conductive testing instrument or an electrochemical workstation for data acquisition; The acquisition equipment includes an image acquisition device, a flow rate sensor, and a pressure sensor. The image acquisition device is respectively installed on the upper side of the corrosion inhibitor filling cabin and the corrosion inhibitor experimental cabin, and the flow rate sensor and pressure sensor are installed in the corrosion inhibitor experimental cabin.

2. The device for simulating the flow of corrosion inhibitor in a pipeline according to claim 1, characterized in that: The corrosion inhibitor filling device includes a timing automatic electric control device, a corrosion inhibitor feeding device, a corrosion inhibitor propulsion sealing piston and a filling corrosion inhibitor storage chamber connected in sequence from top to bottom, and the output port of the filling corrosion inhibitor storage chamber is connected to the input port of the experimental injection conduit.

3. The device for simulating the flow of corrosion inhibitor in a pipeline according to claim 1, characterized in that: The device for simulating the flow of corrosion inhibitor in the pipeline is made of transparent material, which is convenient for flow state observation.

4. A method for evaluating the effect of a corrosion inhibitor, applicable to the device for simulating the flow of a corrosion inhibitor in a pipeline as described in claims 1-3, characterized in that: The following steps are involved: Obtaining evaluation index data of the corrosion inhibitor to be tested, wherein the evaluation index data includes corrosion rate, pre-film resistance, pre-film capacitance, coverage, thickness distribution, continuity, flow rate, pressure, accumulation state and corrosion rate change data of the corrosion inhibitor to be tested; Inputting the evaluation index data into a preset evaluation model to obtain a comprehensive evaluation score output by the preset evaluation model, wherein the preset evaluation model is used to determine the index weights of the evaluation index data using an analytic hierarchy process, quantify the index weights using a fuzzy comprehensive evaluation method, and use a neural network model as a synthesis model; Determine the evaluation grade corresponding to the comprehensive evaluation score in the target preset score range, and output the comprehensive evaluation score and the evaluation grade of the corrosion inhibitor to be tested.

5. The corrosion inhibitor effect evaluation method according to claim 4, wherein The analytic hierarchy process to confirm the indicator weights includes the following steps: Based on the importance of the impact on the corrosion inhibitor effect, the evaluation index data is constructed into a judgment matrix; Calculating the maximum eigenvalue of the judgment matrix and its corresponding eigenvector, and normalizing the eigenvector to obtain a weight vector for each indicator; A consistency check is performed on the judgment matrix to determine whether the weight vector is valid.

6. The corrosion inhibitor effect evaluation method according to claim 5, wherein: The judgment matrix scales the evaluation index data for pairwise comparison, using 1-9 and its reciprocal to represent the results of pairwise comparison, where 1 indicates that the two factors are equally important; 3 indicates that one factor is slightly more important than the other; 5 indicates that one factor is significantly more important than the other; 7 indicates that one factor is strongly more important than the other; 9 indicates that one factor is extremely important than the other; 2, 4, 6, and 8 are intermediate values ​​between the above judgments, and finally a 10x10 judgment matrix is ​​constructed.

7. The corrosion inhibitor effect evaluation method according to claim 5, wherein: The fuzzy comprehensive evaluation method for calculating the quantitative score includes the following steps: Determining an evaluation factor set corresponding to the evaluation index data and a comment set corresponding to the evaluation level; Determine the membership of the evaluation index data to each level in the comment set through expert scoring, and construct a fuzzy relationship matrix; Fuzzy synthesis of the weight vector and the fuzzy relationship matrix to obtain a comprehensive evaluation vector; The quantitative score is calculated using a weighted average method.

8. The corrosion inhibitor effect evaluation method according to claim 4, wherein The evaluation grade includes four grades corresponding to the corrosion inhibitor effect, including excellent, good, general and poor grades, the excellent grade is 85-100 points, the good is 70-84 points, the general is 60-69 points, and the poor is less than 60 points.

Images