Slurry shield slurry discharge pipeline erosive wear experiment device and method

Abstract

The invention discloses an erosive wear experimental device and method for a slurry discharge pipeline of a slurry shield, and relates to the technical field of tunnel engineering.The erosive wear experimental device comprises a high-pressure sand blasting machine, an air compressor is arranged on one side of the high-pressure sand blasting machine, and the high-pressure sand blasting machine is connected with the air compressor through an air pipe; a target material clamp is arranged in the high-pressure sand blasting machine, a target material body is arranged in the target material clamp, and a particle speed measuring assembly is arranged at the bottom of the high-pressure sand blasting machine. According to the method, the problem that an existing wear model is poor in applicability to prediction of wear of the slurry shield slurry discharging pipeline in the abrasive sand layer is solved, the applicability and calculation precision of the wear model are improved, test equipment for erosive wear of a target material through abrasive gravel is used in a laboratory, a wear calculation equation with engineering applicability is established, and the test efficiency is improved. The abrasion prediction precision of the slurry discharge pipeline of the slurry shield is improved, and repair welding or pipe replacement measures are taken in time, so that the shutdown overhaul of the shield machine caused by the risks of pipeline damage, slurry leakage and the like is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering, and in particular to a slurry shield drainage pipeline erosion and wear test device and method. Background Art

[0002] With the continuous development of economy, the continuous improvement of comprehensive national strength and the continuous application of high-tech, my country's tunnel and underground engineering has achieved unprecedented rapid development, and higher requirements have been put forward for shield technology in various complex environments. The slurry circulation system is an important part of the slurry balance shield. It uses pipeline transportation to discharge the slurry carrying excavated slag from the slurry discharge pipeline.

[0003] The large amount of gravel carried in the mud causes serious pipe wear, and even causes pipe damage and wear in the curved section, slurry leakage and other potential risks, forcing the shield machine to shut down for maintenance, increasing project time and economic costs. The pipe 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. Gravel is much larger than such fine particles. There are limitations in using existing wear models to study its wear, resulting in low wear prediction accuracy. Therefore, it is necessary to systematically explore the problem of gravel erosion and wear in the slurry discharge pipeline of slurry shield and propose an applicable high-precision wear equation.

[0004] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0005] In view of the problems in the related technology, the present invention proposes a slurry shield drainage pipeline erosion and wear test device and method to overcome the above-mentioned technical problems existing in the existing related technology.

[0006] To this end, the specific technical solution adopted by the present invention is as follows:

[0007] According to one aspect of the present invention, a slurry shield drainage pipeline erosion and wear test device is provided, the wear test device comprises a high-pressure sandblasting machine, an air compressor is arranged on one side of the high-pressure sandblasting machine, and the high-pressure sandblasting machine is connected to the air compressor through an air pipe; a target material fixture is arranged inside the high-pressure sandblasting machine, a target body is arranged inside the target material fixture, and a particle speed measuring component is arranged at the bottom of the high-pressure sandblasting machine.

[0008] Preferably, the high-pressure sandblasting machine includes a high-pressure sandblasting machine body arranged on one side of the air compressor, a material bin is arranged at the inner bottom of the high-pressure sandblasting machine body, a sandblasting bin is arranged at the middle position inside the high-pressure sandblasting machine body, a pressure gauge, a timer and a knob are arranged in sequence on the outer top of the high-pressure sandblasting machine body, and working bin gloves are symmetrically arranged on both sides of the outer bottom of the high-pressure sandblasting machine body.

[0009] Preferably, the target material clamp includes a bracket base arranged inside the high-pressure sandblasting machine, a clamp body is arranged on the top of the bracket base, and the bracket base and the clamp body are connected by angle fastening screws, a target material body is arranged inside the clamp body, and the clamp body and the target material body are connected by clamp screws.

[0010] Preferably, the particle speed measuring assembly includes a digital speed regulator arranged on one side of the bottom of the high-pressure sandblasting machine, an AC speed regulating motor is arranged on one side of the digital speed regulator, a coupling is arranged on the top of the AC speed regulating motor, a shaft is arranged on the top of the coupling, a notched disc is sleeved on the outer side of the circumference of the shaft, and a complete disc is sleeved on the outer side of the circumference of the shaft and at the bottom end of the notched disc.

[0011] According to another aspect of the present invention, a slurry shield drainage pipeline erosion and wear test method is also provided, characterized in that the slurry shield drainage pipeline erosion and wear test method comprises the following steps:

[0012] S1. Design a wear test plan based on the actual slurry shield circulation system pipeline layout and slurry flow rate, and perform the wear test according to the wear test plan;

[0013] S2, using a particle velocity measuring assembly to measure and record the sandblasting impact velocity of the sand from the notched disc to the intact disc at different sand particle sizes;

[0014] S3, using a high-pressure sandblasting machine to erode and wear the surface of the target body at different impact angles, and generate the target body wear amount;

[0015] S4. Analyze the influence of sandblasting impact velocity, impact angle and sand particle size on the target body wear and draw a change curve. Based on the change curve, establish the target body wear model equation.

[0016] Preferably, using a particle velocity measuring assembly to measure and record the sandblasting impact velocity of sand from a notched disc to a complete disc at different sand particle sizes comprises the following steps:

[0017] S21, after putting sand and gravel into the silo, start the high-pressure sandblasting machine, and adjust the high-pressure sandblasting machine to a preset working pressure;

[0018] S22, placing white paper and carbon paper on the surface of the complete disc in sequence, starting the AC speed regulating motor to drive the complete disc and the notched disc to rotate, and adjusting the disc speed to a preset value and then keeping it constant through the digital speed regulator;

[0019] S23, using a high-pressure sandblasting machine to spray the sand on the notched disc through the slits and hit the carbon paper on the surface of the intact disc, and generate a striking mark feature on the white paper;

[0020] S24, calculating the deflection angle formed by the start and end positions of the gravel trace based on the striking trace characteristics, and calculating the sandblasting impact velocity in combination with the deflection angle;

[0021] S25, adjusting the working pressure of the high-pressure sandblasting machine and the particle size of the sand, repeating steps S21 to S24, and recording the sandblasting impact speeds corresponding to different working pressures.

[0022] Preferably, the calculation formula for the sandblasting impact velocity is:

[0023]

[0024] Where V is the impact velocity of sandblasting; L is the distance between the notched disc and the complete disc; ω d represents the disc speed; γ AB Indicates the deflection angle formed by the starting and ending positions of the gravel trace on the complete disc.

[0025] Preferably, the surface of the target body is eroded and worn by a high-pressure sandblasting machine at different impact angles, and the target body wear amount is generated, including:

[0026] S31, selecting a target body of a preset size, cleaning the surface impurities of the target body, and then weighing and recording the target body;

[0027] S32, after putting sand and gravel into the silo, start the high-pressure sandblasting machine, and adjust the high-pressure sandblasting machine to a preset working pressure;

[0028] S33, placing the installed target body into a sandblasting chamber, and allowing the sand to impact and wear the target body from an incident angle at a preset speed, and after a preset wear time period, turning off the high-pressure sandblasting machine and taking out the target body;

[0029] S34, measuring and recording the mass loss of the target body before and after the impact wear time and the mass of the abrasive consumed in the abrasive bin during the current time period to obtain the wear amount of the target body;

[0030] S35, replace the target body with a different material and adjust the angle of the target body, then repeat steps S1 to S3, and record the wear amount of the target body under different material conditions.

[0031] Preferably, the influence of the sandblasting impact velocity, impact angle and grit particle size on the target body wear is analyzed and a change curve is drawn. The target body wear model equation is selected and established based on the change curve, including:

[0032] S41, calculating the average wear amount of the target body under different material conditions, and drawing the variation curves of the sandblasting impact velocity, impact angle and grit particle size on the wear amount of the target body;

[0033] S42, establishing a wear model form, and generating a target material wear model equation after fitting each change curve according to the change curve diagram and the wear model form.

[0034] Preferably, the expression of the wear model is:

[0035] R erosion =C·f(d p )f(θ)v b(v) ;

[0036] In the formula, R erosion represents the wear rate of the target body; f(d p ) represents the sand particle size function; f(θ) represents the impact angle function; b(v) represents the sandblasting impact velocity index; C represents the coefficient.

[0037] The beneficial effects of the present invention are:

[0038] 1. The present invention overcomes the problem of poor applicability of existing wear models for predicting wear of slurry discharge pipes of slurry shields in abrasive sand layers, improves the applicability and calculation accuracy of wear models, uses test equipment for abrasive gravel erosion and wear targets in the laboratory, establishes wear calculation equations with engineering applicability, improves the wear prediction accuracy of slurry discharge pipes of slurry shields, and promptly takes measures such as repair welding or pipe replacement, thereby reducing the risks of pipeline damage, slurry leakage, etc. that cause shield machine shutdown and maintenance, saving time and cost.

[0039] 2. The present invention reveals the wear law of gravel by establishing the wear equation of abrasive gravel, which is more consistent with actual engineering. For the slurry shield circulation system, the slag impact velocity in the test is set according to the slurry flow rate variation range, thereby improving the accuracy of the test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] 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.

[0041] Figure 1 This is a flow chart of a method for testing erosion and wear of a slurry discharge pipeline of a slurry shield according to an embodiment of the present invention;

[0042] Figure 2 It is a structural schematic diagram of a high-pressure sandblasting machine and an air compressor in a slurry shield drainage pipeline erosion and wear experimental device according to an embodiment of the present invention;

[0043] Figure 3It is a structural schematic diagram of a particle velocity measurement component in a slurry shield discharge pipeline erosion and wear experimental device according to an embodiment of the present invention;

[0044] Figure 4 It is a structural schematic diagram of another angle of a particle velocity measuring component in a slurry shield discharge pipeline erosion and wear experimental device according to an embodiment of the present invention;

[0045] Figure 5 It is a schematic structural diagram of a target material fixture in a slurry shield discharge pipeline erosion and wear experimental device according to an embodiment of the present invention;

[0046] Figure 6 is a schematic structural diagram of another angle of a target material fixture in a slurry shield discharge pipeline erosion and wear experimental device according to an embodiment of the present invention;

[0047] Figure 7 It is one of the particle velocity measurement test results in a slurry shield drainage pipeline erosion and wear test method according to an embodiment of the present invention;

[0048] Figure 8 This is the second result of the particle velocity measurement test in the erosion and wear test method of the slurry discharge pipeline of a slurry shield according to an embodiment of the present invention;

[0049] Fig. 9 This is the third particle velocity measurement test result in a slurry shield drainage pipeline erosion and wear test method according to an embodiment of the present invention;

[0050] Fig.10 This is the fourth particle velocity measurement test result in a slurry shield drainage pipeline erosion and wear test method according to an embodiment of the present invention;

[0051] Fig.11 is a curve diagram of particle velocity and target material wear rate in a slurry shield drainage pipeline erosion wear test method according to an embodiment of the present invention;

[0052] Fig.12 is a graph of impact angle and target wear rate in a slurry shield drainage pipeline erosion wear test method according to an embodiment of the present invention;

[0053] Fig.13 is a curve diagram of particle size and target material wear rate in a slurry shield drainage pipeline erosion wear test method according to an embodiment of the present invention;

[0054] Fig.14 The present invention is a graph showing the incidence angle and target wear rate at different speeds in a slurry shield drainage pipeline erosion wear test method according to an embodiment of the present invention.

[0055] In the figure:

[0056] 1. High-pressure sandblasting machine; 101. High-pressure sandblasting machine body; 102. Material bin; 103. Pressure gauge; 104. Timer; 105. Knob; 106. Work chamber gloves; 107. Sandblasting chamber; 2. Air compressor; 3. Air pipe; 4. Target material fixture; 401. Bracket base; 402. Fixture body; 403. Angle fastening screw; 404. Fixture screw; 5. Target material body; 6. Particle speed measurement assembly; 601. Digital speed regulator; 602. AC speed regulating motor; 603. Coupling; 604. Notched disc; 605. Complete disc; 606. Shaft. DETAILED DESCRIPTION

[0057] 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.

[0058] According to an embodiment of the present invention, a slurry shield drainage pipeline erosion and wear test device and method are provided.

[0059] The present invention is further described with reference to the accompanying drawings and specific embodiments. Figure 2-Figure 6 As shown, a slurry shield discharge pipeline erosion and wear test device according to an embodiment of the present invention comprises a high-pressure sandblasting machine 1, an air compressor 2 is arranged on one side of the high-pressure sandblasting machine 1, and the high-pressure sandblasting machine 1 is connected to the air compressor 2 through an air pipe 3; a target material fixture 4 is arranged inside the high-pressure sandblasting machine 1, a target material body 5 is arranged inside the target material fixture 4, and a particle speed measuring component 6 is arranged at the bottom of the high-pressure sandblasting machine 1.

[0060] Specifically, the high-pressure sandblasting machine 1 is used to shoot sand and gravel from the silo 102 into the sandblasting chamber 107; the air compressor 2 is used to provide power for the high-pressure sandblasting machine 1 and is connected to the high-pressure sandblasting machine through the air pipe 3; the target material clamp 4 is used to adjust the inclination angle of the target material body 5; the particle speed measurement and rotation speed assembly is used to measure the speed of the sand and gravel after being shot out from the muzzle.

[0061] Specifically, the experimental target body 5 is a plate with a size of 200 mm*200 mm*3 mm, and the target material is Q235 and Q345 steel, which are common slurry discharge pipe materials for slurry shields.

[0062] In one embodiment, the high-pressure sandblasting machine 1 includes a high-pressure sandblasting machine body 101 arranged on one side of the air compressor 2, a material bin 102 is arranged at the inner bottom of the high-pressure sandblasting machine body 101, a sandblasting bin 107 is arranged at the middle position inside the high-pressure sandblasting machine body 101, a pressure gauge 103, a timer 104 and a knob 105 are arranged in sequence on the outer top of the high-pressure sandblasting machine body 101, and working bin gloves 106 are symmetrically arranged on both sides of the outer bottom of the high-pressure sandblasting machine body 101.

[0063] Specifically, the spray gun of the high-pressure sandblasting machine 1 is fixed in the sandblasting chamber 107, the caliber of the spray gun is 12 mm, and the compressed air provided by the air compressor 2 is used as the power to shoot sand and gravel from the muzzle. The sandblasting operation is performed using a work chamber glove 106. The working pressure of the high-pressure sandblasting machine 1 is adjusted by a knob 105 and displayed on a pressure gauge 103. The working pressure adjustment range is 0-0.8 MPa, and the working time is displayed by a timer 104.

[0064] In one embodiment, the target material clamp 4 includes a support base 401 arranged inside the high-pressure sandblasting machine 1, a clamp body 402 is arranged on the top of the support base 401, and the support base 401 and the clamp body 402 are connected by an angle fastening screw 403, a target material body 5 is arranged inside the clamp body 402, and the clamp body 402 and the target material body 5 are connected by a clamp screw 404.

[0065] In one embodiment, the particle speed measuring assembly 6 includes a digital speed regulator 601 arranged on one side of the bottom of the high-pressure sandblasting machine 1, an AC speed regulating motor 602 is arranged on one side of the digital speed regulator 601, a coupling 603 is arranged on the top of the AC speed regulating motor 602, a shaft 606 is arranged on the top of the coupling 603, a notched disc 604 is sleeved on the outer side of the circumference of the shaft 606, and a complete disc 605 is sleeved on the outer side of the circumference of the shaft 606 and at the bottom end of the notched disc 604.

[0066] Specifically, a 25W AC speed regulating motor 602 is connected to a shaft 606 by using a coupling 603. Two discs are welded to the shaft 606. The upper disc is a notched disc 604, and the notch range is controlled at 15°. The lower disc is a complete disc 605. Gravel passes through the gap of the upper disc and hits the lower disc. The speed of the AC speed regulating motor 602 is controlled by a digital speed regulator 601.

[0067] In the present invention, abrasive gravel with sharp edges is selected, and the particles are grouped according to the average particle size through vibration screening. The average particle size is defined as the calculated value of the particle size distribution curve using the integral mean theorem; the present invention calculates the wear rate based on the ratio of the target material loss mass to the total mass of the gravel, designs experiments using the gravel particle size, impact velocity and impact angle as independent variables, and performs fitting analysis on the test results to establish a wear prediction equation.

[0068] like Figure 1 According to another embodiment of the present invention, a method for testing erosion and wear of a slurry discharge pipe of a slurry shield is provided. The method for testing erosion and wear of a slurry discharge pipe of a slurry shield comprises the following steps:

[0069] S1. Design a wear test plan based on the actual pipeline layout and slurry flow rate of the slurry shield circulation system, and perform the wear test according to the wear test plan.

[0070] It should be noted that the target material with a size of 200mm*200mm*3mm is made of Q235 and Q345 steel, which are common materials for slurry shield discharge pipes. The rust and stains on the surface of the target material are cleaned with sandpaper, and the weighing is recorded on a high-precision electronic scale. The surface is cleaned before subsequent target weighing. The slurry flow rate in the slurry discharge pipe of the slurry shield is usually above 3m / s to ensure smooth slurry discharge without blockage in the pipe. The wear experiment plan is designed for the impact velocity, impact angle, and particle size.

[0071] S2. Use the particle velocity measuring assembly 6 to measure and record the sandblasting impact velocity of the sand from the notched disc 604 to the complete disc 605 at different sand particle sizes.

[0072] The method of measuring and recording the sandblasting impact velocity of the sand from the notched disc 604 to the complete disc 605 with different sand particle sizes by using the particle velocity measuring component 6 includes the following steps:

[0073] S21, after putting sand and gravel into the silo, start the high-pressure sandblasting machine 1, and adjust the high-pressure sandblasting machine 1 to a preset working pressure;

[0074] S22, placing white paper and carbon paper on the surface of the complete disc 605 in sequence, starting the AC speed regulating motor 602 to drive the complete disc 605 and the notched disc 604 to rotate, and adjusting the disc speed to a preset value and then keeping it constant through the digital speed regulator 601;

[0075] S23, using the high-pressure sandblasting machine 1 to spray the sand on the notched disc 604 through the slits and hit the carbon paper on the surface of the intact disc 605, and generate a striking mark feature on the white paper;

[0076] S24. Calculate the deflection angle formed by the start and end positions of the gravel trace based on the striking trace characteristics, and calculate the sandblasting impact velocity in combination with the deflection angle.

[0077] It should be noted that if Figure 7-10As shown, prepare white paper and carbon paper of the same size as the lower disc and place them on the lower disc in turn, start the AC speed regulating motor 602 to make the upper and lower discs start to rotate, and adjust the disc speed to a suitable value and keep it constant through the digital speed regulator 601. After the sand passes through the slit of the upper disc and hits the carbon paper on the surface of the lower disc, it will leave marks on the lower white paper, and the average speed of the particles passing the distance L can be calculated. Repeat the test to obtain the corresponding relationship between the working pressure and the sandblasting speed, where the calculation formula of the sandblasting impact speed is:

[0078]

[0079] Where V is the impact velocity of sandblasting; L is the distance between the notched disc and the complete disc; ω d represents the disc speed; γ AB Indicates the deflection angle formed by the starting and ending positions of the gravel trace on the complete disc.

[0080] S25, adjusting the working pressure of the high-pressure sandblasting machine 1 and the particle size of the sand, repeating steps S21 to S24, and recording the sandblasting impact speeds corresponding to different working pressures.

[0081] S3, using the high pressure sandblasting machine 1 to erode and wear the surface of the target body 5 at different impact angles, and generating the target body wear amount.

[0082] The high pressure sandblasting machine 1 is used to erode and wear the surface of the target body 5 at different impact angles, and the target body wear amount generated includes:

[0083] S31, selecting a target body 5 of a preset size, cleaning the surface impurities of the target body 5, and then weighing and recording the target body 5;

[0084] S32, after putting sand and gravel into the silo 102, start the high-pressure sandblasting machine 1, and adjust the high-pressure sandblasting machine 1 to a preset working pressure;

[0085] S33, placing the installed target body 5 into the sandblasting chamber 107, and allowing the sand to impact and wear the target body 5 from an incident angle at a preset speed. After the preset wear time period, the high-pressure sandblasting machine 1 is turned off and the target body 5 is taken out;

[0086] S34, measuring and recording the mass loss of the target body 5 before and after the impact wear time and the mass of the abrasive consumed in the abrasive bin during the current time period, and obtaining the wear amount of the target body;

[0087] S35 , replacing the target body 5 with a different material and adjusting the angle of the target body 5 , and then repeating steps S1 to S3 , and recording the wear amount of the target body under different material conditions.

[0088] It should be noted that sandpaper is used to clean rust and stains on the surface of the target material, and the weight is recorded on a high-precision electronic scale. The working pressure of the high-pressure sandblasting machine 1 is adjusted to the pressure value corresponding to the specified speed; after the fixture body 402 is tilted to the specified angle, the angle tightening screw 403 is tightened to complete the fixation; the cleaned target body 5 is placed in the fixture, and the fixture screw 404 is tightened to complete the fixation; the experimental equipment is turned on, and after the working pressure stabilizes, the sandblasting switch is pressed to erode and wear the surface of the target body 5. After three minutes of wear, the high-pressure sandblasting machine 1 is turned off and the target body 5 is removed. The mass change of the target body 5 before and after this period of time and the mass of the abrasive consumed in the abrasive bin during this period of time are measured and recorded, and the target body 5 is re-fixed and placed in the sandblasting bin 107 for continued wear, and then the test parameters are adjusted to repeat steps S1-S3.

[0089] S4. Analyze the influence of sandblasting impact velocity, impact angle and sand particle size on the target body wear and draw a change curve. Based on the change curve, establish the target body wear model equation.

[0090] Among them, the influence of sandblasting impact velocity, impact angle and gravel particle size on the target body wear is analyzed and the change curve is drawn. The target body wear model equation is established based on the change curve, including:

[0091] S41, calculating the average wear amount of the target body under different material conditions, and drawing the variation curves of the sandblasting impact velocity, impact angle and grit particle size on the wear amount of the target body;

[0092] S42, establish a wear model form, and generate a target material wear model equation after fitting each change curve according to the change curve diagram and the wear model form. The change curve diagram is as follows: Figure 11-Figure 14 shown.

[0093] The expression of the wear model is:

[0094] R erosion =C·f(d p )f(θ)v b(v) ;

[0095] In the formula, R erosion represents the wear rate of the target body; f(d p ) represents the grit size function; f(θ) represents the impact angle function; b(v) represents the sandblasting impact velocity index; C represents the coefficient (material-related coefficient).

[0096] The following is a further description of the erosion and wear test method for a slurry shield discharge pipeline provided by the present invention in conjunction with a specific embodiment:

[0097] In this embodiment, the test target material is a plate with a size of 20cm*20cm*0.2cm. In the test, the gravel has three particle sizes of 1.28mm, 1.79mm, and 2.46mm. The test method of the equipment for exploring the erosion wear model of gravel in this embodiment includes the following steps:

[0098] Weighing the target material: Make a target material with a size of 20cm*20cm*0.2cm. Taking the commonly used Q235 steel and Q345 steel as examples, use sandpaper to clean the rust and stains on the surface of the target material, and record the weighing on a high-precision electronic scale. The surface will be cleaned before subsequent target weighing.

[0099] Wear plan: The slurry flow rate in the slurry discharge pipeline of the slurry shield is usually above 3m / s to ensure smooth slurry discharge in the pipe without blockage. The five angle settings are 15°, 30°, 45°, 60°, and 90°.

[0100] Particle velocity measurement experiment: prepare white paper and carbon paper of the same size as the lower disc and place them on the lower disc in turn. The principle is to measure the average velocity of the particles passing through the gap of the upper disc (the upper disc is a notched disc) to the lower disc (the lower disc is a complete disc). Because the distance is short, it can be used as the instantaneous velocity of the impact on the lower disc. Start the experimental device to measure the velocity of the particles, which specifically includes:

[0101] Put 5kg of gravel in the silo; turn on the sandblasting machine and air compressor, and adjust the knob working pressure to 0.2MPa; place the particle velocity measuring device directly under the spray gun, with the distance from the upper disc to the spray gun mouth being 6cm;

[0102] Turn on the AC speed regulating motor and let the motor disc start to rotate. Use the digital speed regulator to adjust the motor speed to 400 rpm. After the working pressure stabilizes, the gravel leaves clear marks on the carbon paper after passing through the upper disc.

[0103] The deflection angle formed by measuring the start and end positions of the trace, the sandblasting speed is calculated as follows:

[0104]

[0105] Where, V is the sandblasting impact velocity; L is the distance between the notched disc and the complete disc, which is 50 mm; ω d represents the disc speed; γ AB It indicates the deflection angle formed by the start and end positions of the gravel trace on the complete disc. Repeat the above particle velocity measurement and measure the velocity corresponding to the working pressure.

[0106] Speed ​​adjustment: adjust the working pressure to 0.22MPa, at which time the corresponding value of the particle speed is 2.68m / s.

[0107] Angle adjustment: adjust the target bracket tilt angle to 15° and tighten the angle fastening screws to fix it.

[0108] Target installation: put the cleaned target into the fixture, put the target into the fixture, and tighten the fixture screws to complete the fixation;

[0109] Sandblasting erosion: Turn on the experimental equipment, wait for the working pressure to stabilize, press the sandblasting switch, and erode the surface of the target. After three minutes of wear, turn off the sandblasting machine, remove the target, measure and record the mass change of the target before and after this period of time and the mass of abrasive consumed in the abrasive bin during this period of time, re-fix the target and put it into the sandblasting working bin to continue wearing, and adjust the test parameters to repeat the above steps, which specifically include:

[0110] Use sandpaper to clean the rust and stains on the surface of the target material, and record the weight on a high-precision electronic scale;

[0111] Put 5kg of gravel into the silo, turn on the sandblasting machine and air compressor, use the knob to adjust the working pressure to 0.22MPa, put the installed target into the sandblasting chamber, and after the working pressure stabilizes, the gravel will impact the target from the incident angle at a specified speed;

[0112] After three minutes of accumulated wear, turn off the sandblasting machine, remove the target, measure and record the mass loss of the target before and after this period of time and the mass of abrasive consumed in the abrasive bin during this period of time; after completing one working condition, replace the steel plate, adjust the particle speed and target angle, and repeat the above test steps.

[0113] According to the test results, the influence of impact velocity, impact angle and particle size on the target wear rate is analyzed, and the influence curves of the three parameters are drawn. According to the curves, the appropriate fitting equation form is selected, and finally the large-size slag impact wear equation is established, which specifically includes:

[0114] The average wear rate under each test condition was calculated by the ratio of target material loss mass to the total mass of gravel, and the variation curves of target material wear rate at different impact speeds, impact angles and particle sizes were plotted respectively.

[0115] The general wear model is established as follows:

[0116] R erosion =C·f(d p )f(θ)v b(v) ;

[0117] In the formula, R erosion represents the wear rate of the target body; f(d p ) represents the sand particle size function; f(θ) represents the impact angle function; b(v) represents the sandblasting impact velocity index; C represents the coefficient.

[0118] The function form was preliminarily determined based on the obtained image. The particle size function form was a linear function, the impact angle function form was a quartic function, and the velocity index and shape coefficient were both constants.

[0119] Using the Matlab fitting toolbox and according to the obtained curve graph and the determined function form, the three function curves are fitted respectively. In this embodiment, the wear model equations of Q235 and Q345 targets are established as follows:

[0120] ER1=1.006×10 -10 (5.18d p +3.62)

[0121] (7.23θ-0.165θ 2 +1.16×10 -3 θ 3 -1.98×10 -6 θ 4 )v 1.88 ;

[0122] ER2=1.965×10 -10 (4.06d p +2.46)

[0123] (7.75θ-0.228θ 2 +2.49×10 -3 θ 3 -9.58×10 -6 θ 4 )v 1.53 ;

[0124] Where, ER1 represents the wear model equation of Q235 target material; ER2 represents the wear model equation of Q345 target material; d p represents the sand particle size; v represents the sandblasting impact velocity.

[0125] In summary, with the help of the above technical solutions of the present invention, the present invention overcomes the problem of poor applicability of the existing wear model to the wear prediction of the slurry discharge pipeline of the slurry shield in the abrasive sand layer, improves the applicability and calculation accuracy of the wear model, uses the test equipment of the abrasive gravel erosion wear target in the laboratory, establishes the wear calculation equation with engineering applicability, improves the wear prediction accuracy of the slurry discharge pipeline of the slurry shield, and takes timely measures of welding or pipe replacement, thereby reducing the risks of pipeline damage, slurry leakage, etc., which causes the shield machine to shut down for maintenance and save time and cost. The present invention reveals the wear law of gravel by establishing the wear equation of abrasive gravel, which is more consistent with the actual project. For the slurry shield circulation system, the slag impact velocity in the test is set according to the range of slurry flow rate, thereby improving the accuracy of the test data.

[0126] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0127] 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 slurry shield drainage pipeline erosion and wear test device, characterized in that: The wear test device comprises a high-pressure sandblasting machine (1), an air compressor (2) is arranged on one side of the high-pressure sandblasting machine (1), and the high-pressure sandblasting machine (1) is connected to the air compressor (2) via an air pipe (3); A target material fixture (4) is arranged inside the high-pressure sandblasting machine (1), a target material body (5) is arranged inside the target material fixture (4), and a particle velocity measuring component (6) is arranged at the bottom of the high-pressure sandblasting machine (1).

2. The erosion and wear test device for slurry discharge pipeline of a slurry shield according to claim 1 is characterized in that: The high-pressure sandblasting machine (1) comprises a high-pressure sandblasting machine body (101) arranged on one side of the air compressor (2); a material bin (102) is arranged at the inner bottom of the high-pressure sandblasting machine body (101); a sandblasting bin (107) is arranged at the middle position inside the high-pressure sandblasting machine body (101); a pressure gauge (103), a timer (104) and a knob (105) are arranged in sequence on the outer top of the high-pressure sandblasting machine body (101); and working bin gloves (106) are symmetrically arranged on both sides of the outer bottom of the high-pressure sandblasting machine body (101).

3. The erosion and wear test device for slurry discharge pipeline of a slurry shield according to claim 2 is characterized in that: The target material clamp (4) comprises a support base (401) arranged inside the high-pressure sandblasting machine (1), a clamp body (402) is arranged on the top of the support base (401), and the support base (401) and the clamp body (402) are connected via an angle fastening screw (403), the target material body (5) is arranged inside the clamp body (402), and the clamp body (402) and the target material body (5) are connected via a clamp screw (404).

4. The erosion and wear test device for slurry discharge pipeline of a slurry shield according to claim 3 is characterized in that: The particle speed measuring assembly (6) comprises a digital speed regulator (601) arranged at one side of the bottom of the high-pressure sandblasting machine (1); an AC speed regulating motor (602) is arranged at one side of the digital speed regulator (601); a coupling (603) is arranged at the top of the AC speed regulating motor (602); a shaft (606) is arranged at the top of the coupling (603); a notched disc (604) is sleeved on the outer side of the circumference of the shaft (606); and a complete disc (605) is sleeved on the outer side of the circumference of the shaft (606) and at the bottom end of the notched disc (604).

5. A method for testing erosion and wear of a slurry shield discharge pipe, used to implement the wear test of the erosion and wear test device for a slurry shield discharge pipe according to any one of claims 1 to 4, characterized in that: The erosion and wear test method of the slurry shield discharge pipe includes the following steps: S1. Design a wear test plan based on the actual slurry shield circulation system pipeline layout and slurry flow rate, and perform the wear test according to the wear test plan; S2, using a particle velocity measuring assembly (6) to measure and record the sandblasting impact velocity of the sand at different sand particle sizes from the notched disc (604) to the complete disc (605); S3, using a high-pressure sandblasting machine (1) to erode and wear the surface of the target body (5) at different impact angles, and generating the target body wear amount; S4. Analyze the influence of sandblasting impact velocity, impact angle and sand particle size on the target body wear and draw a change curve. Based on the change curve, establish the target body wear model equation.

6. A slurry shield drainage pipeline erosion and wear test method according to claim 5, characterized in that: The method of measuring and recording the sandblasting impact velocity of sand from the notched disc (604) to the complete disc (605) with different sand particle sizes by using the particle velocity measuring component (6) comprises the following steps: S21, after putting sand and gravel into the silo (102), start the high-pressure sandblasting machine (1), and adjust the high-pressure sandblasting machine (1) to a preset working pressure; S22, placing white paper and carbon paper on the surface of the complete disc (605) in sequence, starting the AC speed regulating motor (602) to drive the complete disc (605) and the notched disc (604) to rotate, and adjusting the disc speed to a preset value through the digital speed regulator (601) and then keeping it constant; S23, using a high-pressure sandblasting machine (1) to spray the sand on the notched disc (604) through the slits onto the carbon paper on the surface of the intact disc (605), and generating striking mark features on the white paper; S24, calculating the deflection angle formed by the start and end positions of the gravel trace based on the striking trace characteristics, and calculating the sandblasting impact velocity in combination with the deflection angle; S25, adjusting the working pressure and the particle size of the sand blasting machine (1), repeating steps S21 to S24, and recording the corresponding sand blasting impact speeds under different working pressures.

7. A slurry shield drainage pipeline erosion and wear test method according to claim 6, characterized in that: The calculation formula of the sandblasting impact velocity is: Where V is the impact velocity of sandblasting; L is the distance between the notched disc and the complete disc; ω d represents the disc speed; γ AB Indicates the deflection angle formed by the starting and ending positions of the gravel trace on the complete disc.

8. A slurry shield drainage pipeline erosion and wear test method according to claim 7, characterized in that: The method of using a high-pressure sandblasting machine (1) to erode and wear the surface of the target body (5) at different impact angles and generating the target body wear amount comprises: S31, selecting a target body (5) of a preset size, cleaning the surface impurities of the target body (5), and then weighing and recording the target body (5); S32, after putting sand and gravel into the silo (102), start the high-pressure sandblasting machine (1), and adjust the high-pressure sandblasting machine (1) to a preset working pressure; S33, placing the installed target body (5) into a sandblasting chamber (107), causing sand to impact and wear the target body (5) from an incident angle at a preset speed, and after a preset wear period, turning off the high-pressure sandblasting machine (1) and taking out the target body (5); S34, measuring and recording the mass loss of the target body (5) before and after the impact wear time and the mass of the abrasive consumed in the abrasive bin during the current time period, and obtaining the wear amount of the target body; S35, replacing the target body (5) with a different material and adjusting the angle of the target body (5), then repeating steps S1 to S3, and recording the wear amount of the target body under different material conditions.

9. A slurry shield drainage pipeline erosion and wear test method according to claim 8, characterized in that: The analysis of the influence of the sandblasting impact velocity, impact angle and grit particle size on the target body wear and drawing a change curve, and the target body wear model equation selected based on the change curve include: S41, calculating the average wear amount of the target body under different material conditions, and drawing the variation curves of the sandblasting impact velocity, impact angle and grit particle size on the wear amount of the target body; S42, establishing a wear model form, and generating a target material wear model equation after fitting each change curve according to the change curve diagram and the wear model form.

10. A slurry shield drainage pipeline erosion and wear test method according to claim 9, characterized in that: The expression of the wear model is: R erosion =C·f(d p )f(θ)v b(v) ; In the formula, R erosion represents the wear rate of the target body; f(d p ) represents the sand particle size function; f(θ) represents the impact angle function; b(v) represents the sandblasting impact velocity index; C represents the coefficient.

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