Abrasion test method and device for large-particle-size slag stone of shield slurry discharging pipeline

Abstract

The invention discloses a shield slurry discharge pipeline large-particle-size slag stone abrasion test method and device, and relates to the technical field of tunnel engineering, and the method comprises the following steps: weighing the initial weight of a cleaned test target material by using a weighing instrument; setting the slurry flow velocity of the shield slurry discharge pipeline according to the arrangement mode of the shield slurry discharge pipeline, determining wear test parameters, and designing a wear test based on the wear test parameters; the height of the slag stone falling pipeline is adjusted through the pipeline support, and the inclination angle of the target material clamp is adjusted through the box-shaped support; putting the slag stone particles into a slag stone falling pipeline through a putting funnel, and calculating the wear rate of the test target material; drawing a change curve of different wear test parameters and the wear rate of the test target material, and fitting the change curve by utilizing a particle size function and an impact angle function to obtain a wear model of the test target material; and correcting the test target wear model by using the model correction coefficient. According to the invention, the wear prediction precision of the shield slurry discharge pipeline is improved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering, and in particular to a method and a device for testing the wear of large-diameter slag in a shield slurry discharge pipeline. Background Art

[0002] With the continuous development of economy and the continuous improvement of science and technology, the demand for infrastructure construction is increasing day by day. Tunnels and underground projects have ushered in unprecedented development opportunities. Various complex geological conditions and construction environments have put forward higher requirements for shield technology. The shield method has become one of the main methods for tunnel and underground project construction due to its advantages of safety, high efficiency and environmental protection. Especially in complex geological conditions such as soft soil and water-rich strata, slurry shield has been widely used due to its excellent adaptability and stability.

[0003] The slurry circulation system is one of the core components of the slurry shield, which is mainly composed of slurry discharge pipelines, slurry treatment equipment, etc. During the shield excavation process, the slurry circulation system discharges the slurry carrying excavated debris from the slurry discharge pipeline through pipeline transportation. The debris particles carried in the slurry will inevitably cause wear on the pipeline, which is particularly obvious at the elbow joints. Long-term wear accumulation may lead to pipeline damage, slurry leakage and other safety hazards, and even force the shield machine to shut down for maintenance, thereby increasing the project time and economic costs. In order to solve this problem, domestic and foreign scholars have conducted a lot of research on the wear mechanism of pipelines in solid-liquid two-phase flow and proposed a variety of wear models.

[0004] However, the existing traditional wear model still has some limitations when applied to the wear problem of large-size slag in shield slurry discharge pipelines. First, the pipeline wear problem of solid-liquid two-phase flow is very complicated. Traditional wear models are mostly aimed at the working conditions of micron-level particle erosion, while the particle size of slag in shield slurry discharge is usually at the centimeter level. There are significant differences in the wear mechanism between the two, which makes it difficult for traditional wear models to accurately describe the wear law of large-size slag; secondly, traditional wear models often ignore the range of slurry flow rate in the slurry shield circulation system, and do not fully consider the effect of particle shape on wear, which makes the test data deviate from the actual engineering conditions and is difficult to reflect the wear characteristics of slag of different shapes in on-site slag discharge.

[0005] These problems lead to the low accuracy of traditional wear models when applied to shield slurry discharge pipelines, which makes it difficult to meet the needs of engineering practice. Therefore, it is urgent to conduct a systematic study on the impact wear of large-size slag in slurry shield discharge pipelines and propose a suitable high-precision wear model to improve the accuracy and reliability of wear prediction.

[0006] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0007] In response to the problems in the related technology, the present invention proposes a test method and device for the wear of large-size slag in shield drainage pipelines, which has the advantages of establishing a wear model with strong engineering applicability, improving the wear prediction accuracy of shield drainage pipelines, reducing the risks of pipeline damage and slurry leakage, reducing the number of shield machine shutdowns and maintenance, and saving time and cost. It also solves the problem that traditional wear models in the prior art are mostly aimed at the working conditions of micron-level particle erosion, and have limitations when used to study the wear of large-size slag, resulting in low wear prediction accuracy.

[0008] To this end, the specific technical solution adopted by the present invention is as follows:

[0009] According to one aspect of the present invention, a method for testing the wear of large-size slag in a shield slurry discharge pipeline is provided. The method for testing the wear of large-size slag in a shield slurry discharge pipeline comprises the following steps:

[0010] S1. Select the geometric size and steel type of the test target, clean the surface of the test target with a grinding tool, and weigh the initial weight of the cleaned test target with a weighing instrument;

[0011] S2. According to the layout of the shield slurry discharge pipeline, set the slurry flow rate of the shield slurry discharge pipeline, determine the wear test parameters, and design the wear test based on the wear test parameters;

[0012] S3. Use the pipe support to adjust the height of the slag falling pipe, and use the box-type support to adjust the inclination angle of the target fixture, and place the cleaned test target in the center of the target fixture and fix it;

[0013] S4, weigh and record the weight of the slag particles before the wear test, put the slag particles into the slag falling pipe through the feeding funnel, carry out the wear test, and record the weight of the slag particles after the wear test, calculate the wear rate of the test target material, and obtain the wear test results;

[0014] S5, by adjusting the wear test parameters, repeating steps S1 to S4, and drawing the change curves of impact velocity, impact angle, particle size, particle shape and test target wear rate respectively according to the wear test results, and establishing a particle size function and an impact angle function according to the change curves, and fitting the change curves using the particle size function and the impact angle function to obtain a test target wear model;

[0015] S6. Based on the integrated development environment, compile the dynamic link library file of the test target wear model, establish the simulation working condition through the discrete element simulation software, and use the model correction coefficient to correct the test target wear model.

[0016] Furthermore, according to the layout of the shield slurry discharge pipeline, the slurry flow rate of the shield slurry discharge pipeline is set, and the wear test parameters are determined. The wear test is designed based on the wear test parameters, including the following steps:

[0017] S21, based on the layout of the shield slurry discharge pipeline, with the goal of not blocking the shield slurry discharge pipeline, setting the slurry flow rate of the shield slurry discharge pipeline;

[0018] S22, determining wear test parameters according to the slurry flow rate of the shield slurry discharge pipeline, the wear test parameters including impact velocity, impact angle, particle size and particle shape;

[0019] S23. Based on the wear test parameters, design wear tests with different impact speeds, impact angles, particle sizes and particle shapes, and set multi-level test angles.

[0020] Furthermore, the initial weight of the slag particles before the wear test is weighed and recorded, and the slag particles are put into the slag drop pipe through the feeding funnel to carry out the wear test, and the remaining weight of the slag particles after the wear test is recorded, and the wear rate of the test target is calculated. The wear test results include:

[0021] S41, weigh and record the initial weight of the slag particles before the wear test, put the slag particles into the delivery funnel, and when the preset test time is reached, remove the test target from the target fixture;

[0022] S42, weighing the remaining weight of the test target material using a weighing instrument, and calculating the wear mass of the test target material in combination with the initial weight of the test target material;

[0023] S43. When the wear mass of the test target material reaches the wear threshold, weigh the remaining mass of the slag particles, record the total used mass of the slag particles, and calculate the wear rate of the test target material.

[0024] Furthermore, the wear threshold includes a spherical particle wear threshold, a triangular prism particle wear threshold, and a flat particle wear threshold;

[0025] The wear mass of the test target is the difference between the initial weight of the test target and the residual weight of the test target;

[0026] The total used mass of the slag particles is the difference between the initial weight of the slag particles and the residual mass of the slag particles;

[0027] The wear rate of the test target is the ratio of the wear mass of the test target to the total mass of the slag particles used.

[0028] Further, by adjusting the wear test parameters, repeating steps S1 to S4, respectively drawing the change curves of impact velocity, impact angle, particle size, particle shape and test target wear rate according to the wear test results, and establishing a particle size function and an impact angle function according to the change curves, and fitting the change curves using the particle size function and the impact angle function to obtain the test target wear model includes the following steps:

[0029] S51, by adjusting different impact speeds, impact angles, particle sizes and particle shapes, repeatedly performing steps S1 to S4 to obtain several wear test results;

[0030] S52, according to the wear test results, respectively draw the change curves of impact velocity, impact angle, particle size, particle shape and test target wear rate;

[0031] S53, based on the change curve, determining the functional form of the test target wear model, including particle size function, impact angle function, velocity index and shape coefficient;

[0032] S54. According to the variation curve of the test target wear rate and the functional form of the test target wear model, a test target wear model is established using mathematical modeling tools.

[0033] Furthermore, the expression of the particle size function is:

[0034] f(d p )=A·d p +B

[0035] In the formula, f(d p ) represents the particle size function, A represents the first constant, d p represents the particle size of slag stone, and B represents the second constant;

[0036] The expression of the impact angle function is:

[0037]

[0038] Where f(θ) represents the impact angle function, θ represents the impact angle, and D i represents the third constant during the i-th fitting;

[0039] The expression of the test target wear model is:

[0040] R=C·f(d p )f(θ)v b(v)

[0041] Where R represents the erosion wear rate, C represents the shape coefficient, v represents the slag particle velocity, and b(v) represents the velocity index.

[0042] Further, based on the integrated development environment, the dynamic link library file of the test target wear model is compiled, and the simulation working condition is established through the discrete element simulation software, and the test target wear model is corrected by using the model correction coefficient, including the following steps:

[0043] S61. Based on the integrated development environment, create a new project file, compile the header file and source file of the test target wear model, and copy them to the directory of the new project file;

[0044] S62, adding a code file to a new project file and compiling it to generate a dynamic link library file of a test target wear model;

[0045] S63. Use discrete element simulation software to set the contact model parameters between particles and geometric bodies, load the dynamic link library file of the test target wear model, establish a simulation condition, and use the model correction coefficient to correct the test target wear model. The model correction coefficient is the ratio of the actual thickness loss of the pipeline to the numerically calculated thickness loss.

[0046] According to another aspect of the present invention, a large-size slag wear test device for a shield slurry discharge pipeline is provided. The large-size slag wear test device for a shield slurry discharge pipeline comprises a delivery funnel;

[0047] A slag falling pipe is arranged at the bottom end of the delivery funnel, a pipe bracket is arranged on the outside of the slag falling pipe, a plurality of pipe clamps matching the slag falling pipe are arranged in the middle of the pipe bracket, a box-type bracket is arranged at the bottom of the pipe bracket, a target material clamp is arranged on the inner side of the box-type bracket, and the bottom end of the slag falling pipe is aligned with the center of the target material clamp, and a slag collecting box is arranged at the bottom end of the box-type bracket.

[0048] Furthermore, the slag rock falling pipe is used to cooperate with the delivery funnel to deliver the slag rock particles;

[0049] The pipe support is used to fix the slag rock falling pipe, and change the height of the slag rock falling pipe through the pipe clamp to adjust the speed of the slag rock particles impacting the test target;

[0050] The target fixture is used to fix the test target;

[0051] The slag collection box is used to collect slag particles after the wear test;

[0052] The box-type bracket is used to adjust the inclination angle of the target fixture to achieve multi-level test angle adjustment.

[0053] Furthermore, a plurality of target limiting bolts are provided through the top of the target fixture, a plurality of limiting holes are symmetrically provided on both sides of the box-shaped bracket, and screws are provided through the limiting holes on both sides of the target fixture;

[0054] Among them, the target limiting bolt is used to fix the position of the test target;

[0055] The screw rod is used to cooperate with the limiting hole to adjust the inclination angle of the target fixture and fix it.

[0056] The beneficial effects of the present invention are:

[0057] (1) By using a test device for impacting wear targets with large-size slag in the laboratory, the present invention establishes a wear model with engineering applicability, which overcomes the problem that the existing wear model has poor applicability to the wear prediction of the slurry discharge pipeline of the slurry shield, and improves the model applicability and calculation accuracy; compared with the experimental background of "high speed and small particle size" of the existing wear model, the applicable scope of the wear model established by the present invention has the characteristics of "low speed and large particle size", which can more accurately predict the wear problem of the slurry discharge pipeline in actual engineering, and timely repair or replace the severely worn parts before the pipeline fails, which helps to solve the shutdown and maintenance problem of the slurry shield caused by damage to the slurry discharge pipeline and slurry leakage, saving time and cost.

[0058] (2) Based on the existing wear model, a wear model for large-size slag is proposed, which reveals the wear law of large-size slag and is more consistent with actual engineering.

[0059] (3) By targeting the slurry shield circulation system and setting the slag impact velocity in the wear test according to the slurry flow rate variation range, the accuracy of the test data is improved.

[0060] (4) By exploring the influence of particle shape on wear, spherical particles are used as the standard test. According to the shape distribution of slag discharged on site, flat slag with edges and triangular prism-shaped slag are selected as test particles, making the research results more comprehensive.

[0061] (5) By adopting numerical simulation methods and combining them with field measurement data, the model was modified to further improve the calculation accuracy of the wear model. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0063] Figure 1 It is a schematic flow chart of a method for testing the wear of large-size slag in a shield slurry discharge pipeline according to an embodiment of the present invention;

[0064] Figure 2 This is a front view of a shield slurry discharge pipeline large-diameter slag wear test device according to an embodiment of the present invention;

[0065] Figure 3 It is a left view of a shield slurry discharge pipeline large-size slag wear test device according to an embodiment of the present invention;

[0066] Figure 4 It is a left view of a box-type support in a large-size slag wear test device for a shield slurry discharge pipeline according to an embodiment of the present invention;

[0067] Figure 5 It is a top view of a box-type support in a large-size slag wear test device for a shield slurry discharge pipeline according to an embodiment of the present invention;

[0068] Figure 6 It is a schematic diagram of a curve of changes in impact velocity and test target wear rate in a shield slurry discharge pipeline large-size slag wear test method according to an embodiment of the present invention;

[0069] Figure 7 It is a schematic diagram of a curve of changes in impact angle and test target wear rate in a shield slurry discharge pipeline large-size slag wear test method according to an embodiment of the present invention;

[0070] Figure 8 The present invention is a schematic diagram of a curve showing changes in particle size and test target wear rate in a shield slurry discharge pipeline large-size slag wear test method according to an embodiment of the present invention.

[0071] In the figure:

[0072] a. Delivery funnel; b. Slag falling pipe; c. Pipe support; d. Pipe clamp; e. Slag collection box; f. Box-type support; g. Limiting hole; h. Screw; i. Target limiting bolt. DETAILED DESCRIPTION

[0073] To further illustrate each embodiment, the present invention provides drawings, which are part of the disclosure of the present invention and are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in the field should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0074] According to an embodiment of the present invention, a method and device for testing the wear of large-diameter slag in a shield slurry discharge pipeline are provided.

[0075] The present invention is further described with reference to the accompanying drawings and specific embodiments. Figure 1 As shown, according to one embodiment of the present invention, a method for testing the wear of large-size slag in a shield slurry discharge pipeline is provided, and the method for testing the wear of large-size slag in a shield slurry discharge pipeline comprises the following steps:

[0076] S1. Select the geometric size and steel type of the test target, clean the surface of the test target with a grinding tool, and weigh the initial weight of the cleaned test target with a weighing instrument;

[0077] S2. According to the layout of the shield slurry discharge pipeline, set the slurry flow rate of the shield slurry discharge pipeline, determine the wear test parameters, and design the wear test based on the wear test parameters;

[0078] S3. Use the pipe support c to adjust the height of the slag falling pipe b, and use the box-type support f to adjust the inclination angle of the target fixture, and place the cleaned test target in the center of the target fixture and fix it;

[0079] S4, weigh and record the weight of the slag particles before the wear test, put the slag particles into the slag falling pipe through the feeding funnel, carry out the wear test, and record the weight of the slag particles after the wear test, calculate the wear rate of the test target material, and obtain the wear test results;

[0080] S5, by adjusting the wear test parameters, repeating steps S1 to S4, and drawing the change curves of impact velocity, impact angle, particle size, particle shape and test target wear rate respectively according to the wear test results, and establishing a particle size function and an impact angle function according to the change curves, and fitting the change curves using the particle size function and the impact angle function to obtain a test target wear model;

[0081] S6. Based on the integrated development environment, compile the dynamic link library file of the test target wear model, establish the simulation working condition through the discrete element simulation software, and use the model correction coefficient to correct the test target wear model.

[0082] Specifically, this test method calculates the wear rate based on the ratio of the target material loss mass to the total mass of the slag particles, takes the impact velocity, impact angle, particle size and particle shape as independent variables to design the test, and performs fitting analysis on the test results to establish a wear prediction equation and obtain a wear model.

[0083] Specifically, in the test, the shape of large-size slag particles is based on spherical particles, and other special-shaped slag particles are selected based on actual working conditions. The particle size of slag particles is based on sampling in the project, which is used to simulate slag particles of different shapes and sizes in actual projects.

[0084] Specifically, in this embodiment, the test target material is selected as a plate with a size of 200mm*200mm*3mm. In the test, the large-size slag stone has three shapes: spherical particles (without edges and corners), triangular prism particles (with edges and corners), and flat particles (with edges and corners), and has three particle sizes of 1cm, 2cm and 3cm respectively, which are used to simulate slag stones of different shapes and particle sizes in actual engineering. In this embodiment, the test method for exploring the impact wear model of large-size slag stone includes the following steps:

[0085] ① Weighing the target: In this embodiment, a test target with a size of 200mm*200mm*3mm is prepared, and the steel type is Q235 steel and Q345 steel. The rust and stains on the surface of the test target are cleaned with sandpaper, and the weighing is recorded on a high-precision electronic scale. The surface is cleaned before the subsequent test target is weighed;

[0086] ② Wear scheme: With the goal of ensuring smooth slurry discharge in the pipe without blockage, the slurry flow rate of the slurry discharge pipeline of the slurry shield is set. In this embodiment, the slurry flow rate is set to be above 3m / s. The common pipeline layout is 90° elbow. Wear tests are designed for different impact speeds, impact angles and particle sizes. The four angle settings are 15°, 30°, 45° and 60° respectively.

[0087] ③Height adjustment: adjust the position of the pipe clamp d on the pipe support c, and adjust the slag falling pipe b to the specified height;

[0088] ④ Angle adjustment: After tilting the target fixture on the box-type bracket f to the specified angle, pass the screw h through the bracket limit hole g and use the nut to complete the fixing operation;

[0089] ⑤ Target installation: Place the cleaned target in the center of the target fixture and use the target limit bolts i to fix the target around;

[0090] ⑥ Throwing slag: This test method defines the wear rate as the ratio of the loss mass of the test target to the total mass of the slag particles used. Before the test, the slag particles are weighed and recorded, and then the slag particles are put in from the upper end of the funnel a. After 1 minute of each throwing, the target on the target fixture is removed and weighed and recorded on a high-precision electronic scale. After each fixed mass of target wear, the remaining slag particle mass is weighed again, and the total mass of slag particles used is recorded. The wear threshold for each fixed mass of target wear is set to 0.2g for spherical particles, 0.3g for triangular prism particles, and 0.3g for flat particles. Repeat the test until the wear rate stabilizes, and then adjust the test parameters and repeat steps ①-⑥;

[0091] ⑦ Experimental data processing: According to the test results, the influence of impact velocity, impact angle, particle size and particle shape on the target wear rate is analyzed, and the influence curves of the four parameters are drawn. According to the curves, the appropriate fitting equation form is selected, and finally the large-size slag impact wear model is established;

[0092] ⑧ Wear model correction: In this embodiment, based on the user-defined contact model method of EDEM API, the wear model file is compiled using Visual Studio tools to generate a dll file, which is loaded into the EDEM contact model and used for model correction and calculation.

[0093] In one embodiment, according to the arrangement of the shield slurry discharge pipeline, the slurry flow rate of the shield slurry discharge pipeline is set, and the wear test parameters are determined. The wear test is designed based on the wear test parameters, including the following steps:

[0094] S21, based on the layout of the shield slurry discharge pipeline, with the goal of not blocking the shield slurry discharge pipeline, setting the slurry flow rate of the shield slurry discharge pipeline;

[0095] S22, determining wear test parameters according to the slurry flow rate of the shield slurry discharge pipeline, the wear test parameters including impact velocity, impact angle, particle size and particle shape;

[0096] S23. Based on the wear test parameters, design wear tests with different impact speeds, impact angles, particle sizes and particle shapes, and set multi-level test angles.

[0097] Specifically, wear tests are designed for different impact velocities, impact angles and particle sizes. In the above embodiment, the multi-stage test angle is set to four levels, including 15°, 30°, 45° and 60°.

[0098] In one embodiment, the initial weight of the slag particles before the wear test is weighed and recorded, the slag particles are put into the slag drop pipe through the feeding funnel, the wear test is carried out, and the remaining weight of the slag particles after the wear test is recorded, and the wear rate of the test target is calculated. The wear test results include:

[0099] S41, weigh and record the initial weight of the slag particles before the wear test, put the slag particles into the delivery funnel a, and when the preset test time is reached, remove the test target from the target fixture;

[0100] S42, weighing the remaining weight of the test target material using a weighing instrument, and calculating the wear mass of the test target material in combination with the initial weight of the test target material;

[0101] S43. When the wear mass of the test target material reaches the wear threshold, weigh the remaining mass of the slag particles, record the total used mass of the slag particles, and calculate the wear rate of the test target material.

[0102] In one embodiment, the wear threshold includes a spherical particle wear threshold, a triangular prism particle wear threshold, and a flat particle wear threshold;

[0103] The wear mass of the test target is the difference between the initial weight of the test target and the residual weight of the test target;

[0104] The total used mass of the slag particles is the difference between the initial weight of the slag particles and the residual mass of the slag particles;

[0105] The wear rate of the test target is the ratio of the wear mass of the test target to the total mass of the slag particles used.

[0106] In one embodiment, by adjusting the wear test parameters, repeating steps S1 to S4, respectively drawing the change curves of impact velocity, impact angle, particle size, particle shape and test target wear rate according to the wear test results, and establishing a particle size function and an impact angle function according to the change curves, and fitting the change curves using the particle size function and the impact angle function to obtain the test target wear model includes the following steps:

[0107] S51, by adjusting different impact speeds, impact angles, particle sizes and particle shapes, repeatedly performing steps S1 to S4 to obtain several wear test results;

[0108] S52, according to the wear test results, respectively draw the change curves of impact velocity, impact angle, particle size, particle shape and test target wear rate;

[0109] S53, based on the change curve, determining the functional form of the test target wear model, including particle size function, impact angle function, velocity index and shape coefficient;

[0110] S54. According to the variation curve of the test target wear rate and the functional form of the test target wear model, a test target wear model is established using mathematical modeling tools.

[0111] Specifically, ⑦ test data processing includes the following steps:

[0112] 1) The average wear rate under each test condition is calculated by the ratio of the target material loss mass to the total mass of the slag particles, and the change curves of the target material wear rate under different impact speeds, impact angles, particle sizes and particle shapes are plotted respectively, such as Figure 6-Figure 8 As shown;

[0113] 2) According to the obtained change curve image, the function form is preliminarily determined. In this embodiment, the particle size function form is set to a linear function, the impact angle function form is set to a quartic function, the velocity index and the shape coefficient are both constants, and the particle size function and the impact angle function equations are as follows:

[0114] The expression of particle size function is:

[0115] f(d p )=A·d p +B

[0116] In the formula, f(d p ) represents the particle size function, A represents the first constant, d p represents the particle size of the slag stone, B represents the second constant, A and B are obtained by fitting the curve of the change of particle size and the wear rate of the test target material, and in this embodiment, the example values ​​A=8.25 and B=35.3 are given;

[0117] The expression of the impact angle function is:

[0118]

[0119] Where f(θ) represents the impact angle function, θ represents the impact angle, and D i represents the third constant in the i-th fitting (in this embodiment, i=1, 2, 3, 4), D i It is given after fitting the curve of impact angle and test target wear rate;

[0120] The wear model is established, and the expression of the test target wear model is:

[0121] R=C·f(d p )f(θ)v b(v)

[0122] In the formula, R represents the erosion wear rate, C represents the shape coefficient, v represents the slag particle velocity, and b(v) represents the velocity index;

[0123] 3) Using a mathematical modeling tool (in this embodiment, the fitting toolbox of MATLAB software is used), the curves are fitted according to the change curve and the determined function form to complete the establishment of the wear model.

[0124] Specifically, in the above embodiment, the equation expression for the wear model of Q235 and Q345 target materials is finally established as follows:

[0125] R Q235 =2.3×10 -12 C(8.25d p +35.3)

[0126] (7.30θ-0.271θ 2 +3.54×10 -3 θ 3 -1.56×10 -5 θ 4 )v 3.06

[0127] R Q345 =5.3×10 -12 C(6.88d p +25.2)

[0128] (6.26θ-0.244θ 2 +3.40×10 -3 θ 3 -1.61×10 -5 θ 4 )v 2.75

[0129] Where, R is the erosion wear rate, unit is kg / kg; d p is the particle size, in mm; θ is the impact angle, in degrees; v is the particle velocity, in m / s; C is the shape coefficient. In this embodiment, the shape coefficients of spherical, flat and triangular prism-shaped slag particles are C=1, 1.4 and 1.8 respectively; 2.3×10 -12 and 5.3×10 -12 These are the fitting constants obtained by fitting the test result data of Q235 and Q345 targets using the fitting toolbox of MATLAB software in this embodiment.

[0130] In one embodiment, based on the integrated development environment, compiling the dynamic link library file of the test target wear model, establishing the simulation condition through discrete element simulation software, and using the model correction coefficient to correct the test target wear model includes the following steps:

[0131] S61. Based on the integrated development environment, create a new project file, compile the header file and source file of the test target wear model, and copy them to the directory of the new project file;

[0132] S62, adding a code file to a new project file and compiling it to generate a dynamic link library file of a test target wear model;

[0133] S63. Use discrete element simulation software to set the contact model parameters between particles and geometric bodies, load the dynamic link library file of the test target wear model, establish a simulation condition, and use the model correction coefficient to correct the test target wear model. The model correction coefficient is the ratio of the actual thickness loss of the pipeline to the numerically calculated thickness loss.

[0134] Specifically, ⑧ wear model correction includes the following steps:

[0135] 1) Create a new dll empty project in the integrated development environment (Visual Studio is used in this embodiment), compile the header file and source file, and copy them and the header file (API Core and API Contact Model files in this embodiment) in the API file of the discrete element simulation software (EDEM is used in this embodiment) to the same file directory to obtain a new project file;

[0136] 2) Add a code file (in this embodiment, a cpp format file) to the new project file and compile it, write the test wear model, and after completion, compile the new project file to generate a dll file;

[0137] 3) In this embodiment, a contact model between particles and geometric bodies is set in EDEM, a dll file is loaded, and a simulation condition is set. Taking a 90-degree elbow pipe worn by large-size slag as an example, the pipe wear thickness in the calculation result is analyzed and compared with the actual wear thickness measurement value, and a model correction coefficient K is introduced, which is expressed as the ratio of the actual thickness loss to the numerically calculated thickness loss. The correction of the wear model is completed, and the equation expression of the corrected wear model is: ER=K×R, where ER represents the erosion wear rate obtained by the corrected wear model, and R represents the erosion wear rate.

[0138] Specifically, in the above embodiment, the K value calculated is 0.82. Specifically, in the above embodiment, the equation expression of the wear model of the Q235 and Q345 target materials after correction is finally established is as follows:

[0139] ER Q235 =1.89×10 -12 C(8.25d p +35.3)

[0140] (7.30θ-0.271θ 2 +3.54×10 -3 θ 3 -1.56×10 -5 θ 4 )v 3.06

[0141] ER Q345 =4.35×10 -12 C(6.88d p +25.2)

[0142] (6.26θ-0.244θ 2 +3.40×10 -3 θ 3 -1.61×10 -5 θ 4 )v 2.75

[0143] Where ER is the erosion wear rate obtained by the modified wear model, in kg / kg; d p is the particle size, in mm; θ is the impact angle, in degrees; v is the particle velocity, in m / s; C is the shape coefficient. In the above embodiment, the shape coefficients of spherical, flat and triangular prism-shaped slag particles are C=1, 1.4 and 1.8 respectively; 1.389×10 -12 and 4.35×10 -12 It is the product of the fitting constant and the model correction coefficient K obtained by fitting the test result data of Q235 and Q345 targets respectively using the fitting toolbox of MATLAB software in this embodiment.

[0144] like Figure 2-Figure 5 As shown, according to another embodiment of the present invention, a shield slurry discharge pipeline large-size slag wear test device is also provided, and the shield slurry discharge pipeline large-size slag wear test device comprises a delivery funnel a;

[0145] A slag falling pipe b is arranged at the bottom end of the delivery funnel a, a pipe bracket c is arranged on the outside of the slag falling pipe b, a plurality of pipe clamps d matching the slag falling pipe b are arranged in the middle of the pipe bracket c, a box-type bracket f is arranged at the bottom of the pipe bracket c, a target material fixture is arranged on the inner side of the box-type bracket f, and the bottom end of the slag falling pipe b is aligned with the center of the target material fixture, and a slag collecting box e is arranged at the bottom end of the box-type bracket f.

[0146] In one embodiment, the slag rock falling pipe b is used to cooperate with the delivery funnel a to deliver slag rock particles;

[0147] The pipe support c is used to fix the slag rock falling pipe b, and the height of the slag rock falling pipe b is changed through the pipe clamp d to adjust the speed of the slag rock particles impacting the test target;

[0148] The target fixture is used to fix the test target;

[0149] The slag collection box e is used to collect slag particles after the wear test;

[0150] The box-type bracket f is used to adjust the inclination angle of the target fixture to achieve multi-level test angle adjustment.

[0151] In one embodiment, a plurality of target limiting bolts i are provided through the top of the target fixture, a plurality of limiting holes g are symmetrically provided on both sides of the box-shaped bracket f, and screws h are provided through the limiting holes g on both sides of the target fixture, and the angle is adjusted between 0 and 90°;

[0152] Among them, the target limiting bolt i is used to fix the position of the test target;

[0153] The screw h is used to cooperate with the limiting hole g to adjust the inclination angle of the target fixture and fix it.

[0154] In summary, with the help of the above-mentioned technical scheme of the present invention, the problem of poor applicability of the existing wear model to the wear prediction of the slurry discharge pipeline of the slurry shield is overcome, and the applicability and calculation accuracy of the model are improved; by using the test equipment of large-size slag impact wear target in the laboratory, a wear model with engineering applicability is established, and the wear prediction accuracy of the shield discharge pipeline is improved, so that timely measures such as welding or pipe replacement can be taken to reduce the risks of pipeline damage, slurry leakage, etc. caused by the shutdown of the shield machine for maintenance, saving time and cost; the present invention proposes a wear model for large-size slag based on the existing wear model, The wear law of large-size slag is revealed, which is more consistent with the actual project; the impact velocity of slag in the wear test is set according to the range of slurry flow rate in the slurry shield circulation system, thereby improving the accuracy of the test data; by exploring the influence of particle shape on wear, spherical particles are used as the standard test, and according to the shape distribution of slag discharged on site, flat slag and triangular prism-shaped slag are selected as test particles, making the research results more comprehensive; by using numerical simulation methods and combining with field measurement data to correct the model, the calculation accuracy of the wear model is further improved.

[0155] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A shield slurry discharge pipeline large-size slag wear test method, characterized in that: The shield slurry discharge pipeline large-size slag wear test method comprises the following steps: S1. Select the geometric size and steel type of the test target, clean the surface of the test target with a grinding tool, and weigh the initial weight of the cleaned test target with a weighing instrument; S2. According to the layout of the shield slurry discharge pipeline, set the slurry flow rate of the shield slurry discharge pipeline, determine the wear test parameters, and design the wear test based on the wear test parameters; S3. Use the pipe support to adjust the height of the slag falling pipe, and use the box-type support to adjust the inclination angle of the target fixture, and place the cleaned test target in the center of the target fixture and fix it; S4, weigh and record the weight of the slag particles before the wear test, put the slag particles into the slag falling pipe through the feeding funnel, carry out the wear test, and record the weight of the slag particles after the wear test, calculate the wear rate of the test target material, and obtain the wear test results; S5, by adjusting the wear test parameters, repeating steps S1 to S4, and drawing the change curves of impact velocity, impact angle, particle size, particle shape and test target wear rate respectively according to the wear test results, and establishing a particle size function and an impact angle function according to the change curves, and fitting the change curves using the particle size function and the impact angle function to obtain a test target wear model; S6. Based on the integrated development environment, compile the dynamic link library file of the test target wear model, establish the simulation working condition through the discrete element simulation software, and use the model correction coefficient to correct the test target wear model.

2. A shield slurry discharge pipeline large-size slag wear test method according to claim 1, characterized in that: According to the arrangement of the shield slurry discharge pipeline, the slurry flow rate of the shield slurry discharge pipeline is set, and the wear test parameters are determined. The wear test is designed based on the wear test parameters, including the following steps: S21, based on the layout of the shield slurry discharge pipeline, with the goal of not blocking the shield slurry discharge pipeline, setting the slurry flow rate of the shield slurry discharge pipeline; S22, determining wear test parameters according to the slurry flow rate of the shield slurry discharge pipeline, wherein the wear test parameters include impact velocity, impact angle, particle size and particle shape; S23. Based on the wear test parameters, design wear tests with different impact speeds, impact angles, particle sizes and particle shapes, and set multi-level test angles.

3. A shield slurry discharge pipeline large-size slag wear test method according to claim 1, characterized in that: The weighing records the initial weight of the slag particles before the wear test, puts the slag particles into the slag drop pipe through the feeding funnel, performs the wear test, and records the remaining weight of the slag particles after the wear test, calculates the wear rate of the test target material, and obtains the wear test results including: S41, weigh and record the initial weight of the slag particles before the wear test, put the slag particles into the delivery funnel, and when the preset test time is reached, remove the test target from the target fixture; S42, weighing the remaining weight of the test target material using a weighing instrument, and calculating the wear mass of the test target material in combination with the initial weight of the test target material; S43. When the wear mass of the test target material reaches the wear threshold, weigh the remaining mass of the slag particles, record the total used mass of the slag particles, and calculate the wear rate of the test target material.

4. A shield slurry discharge pipeline large-size slag wear test method according to claim 3, characterized in that: The wear thresholds include a spherical particle wear threshold, a triangular prism particle wear threshold and a flat particle wear threshold; The wear mass of the test target is the difference between the initial weight of the test target and the residual weight of the test target; The total use mass of the slag particles is the difference between the initial weight of the slag particles and the residual mass of the slag particles; The test target wear rate is the ratio of the wear mass of the test target to the total use mass of the slag particles.

5. A shield slurry discharge pipeline large-size slag wear test method according to claim 1, characterized in that: By adjusting the wear test parameters, steps S1 to S4 are repeatedly performed, and according to the wear test results, the change curves of impact velocity, impact angle, particle size, particle shape and test target wear rate are respectively drawn, and the particle size function and impact angle function are established according to the change curves, and the particle size function and impact angle function are used to fit the change curves to obtain the test target wear model The following steps are involved: S51, by adjusting different impact speeds, impact angles, particle sizes and particle shapes, repeatedly performing steps S1 to S4 to obtain several wear test results; S52, according to the wear test results, respectively draw the change curves of impact velocity, impact angle, particle size, particle shape and test target wear rate; S53, based on the change curve, determining the functional form of the test target wear model, including particle size function, impact angle function, velocity index and shape coefficient; S54. According to the variation curve of the test target wear rate and the functional form of the test target wear model, a test target wear model is established using mathematical modeling tools.

6. A shield slurry discharge pipeline large-size slag wear test method according to claim 5, characterized in that: The expression of the particle size function is: f(dp)=A·dp+B In the formula, f(d p ) represents the particle size function, A represents the first constant, d p represents the particle size of slag stone, and B represents the second constant; The expression of the impact angle function is: Where f(θ) represents the impact angle function, θ represents the impact angle, and D i represents the third constant during the i-th fitting; The expression of the test target wear model is: R=C·f ( dp ) f ( θ ) vb(v) Where R represents the erosion wear rate, C represents the shape coefficient, v represents the slag particle velocity, and b(v) represents the velocity index.

7. A shield slurry discharge pipeline large-size slag wear test method according to claim 1, characterized in that: The method of compiling a dynamic link library file of the test target wear model based on an integrated development environment, establishing a simulation condition through discrete element simulation software, and correcting the test target wear model using a model correction coefficient comprises the following steps: S61. Based on the integrated development environment, create a new project file, compile the header file and source file of the test target wear model, and copy them to the directory of the new project file; S62, adding a code file to a new project file and compiling it to generate a dynamic link library file of a test target wear model; S63. Use discrete element simulation software to set the contact model parameters between particles and geometric bodies, load the dynamic link library file of the test target wear model, establish a simulation condition, and use the model correction coefficient to correct the test target wear model. The model correction coefficient is the ratio of the actual thickness loss of the pipeline to the numerically calculated thickness loss.

8. A shield slurry discharge pipeline large-size slag wear test device, used to implement the shield slurry discharge pipeline large-size slag wear test method according to any one of claims 1 to 7, characterized in that: The shield slurry discharge pipeline large-size slag wear test device includes a delivery funnel; A slag falling pipe is arranged at the bottom end of the delivery funnel, a pipe bracket is arranged on the outer side of the slag falling pipe, a plurality of pipe clamps matching the slag falling pipe are arranged in the middle of the pipe bracket, a box-type bracket is arranged at the bottom of the pipe bracket, a target material clamp is arranged on the inner side of the box-type bracket, and the bottom end of the slag falling pipe is aligned with the center of the target material clamp, and a slag collecting box is arranged at the bottom end of the box-type bracket.

9. A shield slurry discharge pipeline large-size slag wear test device according to claim 8, characterized in that: The slag rock falling pipe is used to cooperate with the delivery funnel to deliver slag rock particles; The pipe support is used to fix the slag rock falling pipe, and to change the height of the slag rock falling pipe through the pipe clamp to adjust the speed of the slag rock particles impacting the test target material; The target material fixture is used to fix the test target material; The slag collection box is used to collect slag particles after the wear test; The box-shaped bracket is used to adjust the inclination angle of the target fixture to achieve multi-level test angle adjustment.

10. A shield slurry discharge pipeline large-size slag wear test device according to claim 9, characterized in that: A plurality of target limiting bolts are provided through the top of the target material clamp, a plurality of limiting holes are symmetrically provided on both sides of the box-shaped bracket, and screws are provided through the limiting holes on both sides of the target material clamp; Wherein, the target limiting bolt is used to fix the position of the test target; The screw rod is used to cooperate with the limiting hole to adjust the inclination angle of the target material fixture and fix it.

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