A method for diagnosing leakage of slurry conveying pipeline

Abstract

The present invention discloses a method for diagnosing leakage of a slurry conveying pipeline, and belongs to the technical field of pipeline leakage diagnosis. The present invention comprises: Q1: establishing a slurry flow model in a conveying pipeline; Q2: introducing a leakage factor into the slurry flow model; Q3: calculating the leakage hole diameter, characteristic pressure, and characteristic velocity. The characteristic pressure, characteristic velocity, and velocity distribution are used to judge the pipeline leakage situation, leakage time, and leakage location, provide guidance to the industrial site, reduce economic losses, etc., and reduce the interference of the external environment on the judgment result during the diagnosis of the conveying pipeline leakage, so as to obtain a more accurate judgment result.

Description

Technical Field

[0001] The invention belongs to the technical field of pipeline leakage diagnosis, and relates to a method for diagnosing leakage of a slurry conveying pipeline. Background Art

[0002] As a traditional heavy industry, mining provides a large amount of raw materials for the development of the national economy. Transporting slurry through pipelines is one of the safest and most economical ways of transportation. However, due to corrosion of the pipe wall or damage to the pipeline, pipeline leakage accidents often occur, resulting in economic losses, waste of resources and environmental pollution. Therefore, it is crucial for the slurry pipeline transportation system to quickly and accurately determine whether the pipeline is leaking, the location of the leak and the time of the leak.

[0003] At present, the main models for slurry pipeline leakage diagnosis include pipeline leakage diagnosis based on acoustic emission, but it is easily affected by noise caused by slurry leakage, resulting in low accuracy of judgment results; pipeline leakage diagnosis based on electromechanical impedance, because part of the pipeline is exposed on the surface, it is greatly affected by the environment and is prone to problems such as low diagnostic efficiency under high temperature; pipeline leakage diagnosis based on capacitive sensors, because the sensor needs to be in direct contact with the leaking slurry and is easily corroded, this method is easily affected by false alarms.

[0004] Therefore, it is necessary to provide a method for diagnosing leakage in a slurry conveying pipeline to reduce the impact of other environmental factors on the diagnosis process, make the diagnosis result more accurate, and achieve the purpose of quickly and accurately determining the pipeline leakage situation, leakage location, and leakage occurrence time. Summary of the invention

[0005] In order to overcome the problems in the background technology, the present invention proposes a method for diagnosing leakage in a slurry conveying pipeline. By establishing a slurry flow model in the conveying pipeline and introducing the leakage factor into the slurry flow model, the leakage diagnosis model and the turbulence model are solved by using ANSYS Fluent software, and then the characteristic pressure, characteristic velocity and velocity distribution can be used to determine the pipeline leakage situation, leakage time and leakage location.

[0006] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0007] The leakage diagnosis method comprises the following steps:

[0008] Q1: Establish an axial flow model of slurry in a basic pipe section. The basic pipe section is a slurry conveying pipeline that is infinitely subdivided, and the smallest unit of the pipeline is the basic pipe section;

[0009] Q2: Calculate the leakage factor K L , and the leakage factor K LIntroducing the axial flow model established in step Q1 to establish a slurry conveying pipeline leakage diagnosis model;

[0010] Q3: Use ANSYS Fluent software to solve the slurry pipeline leakage diagnosis model obtained in step Q2 and the standard k-ε turbulence model to obtain the slurry flow velocity v in the pipeline at different times t And the pipeline pressure p t , where v t is the slurry flow rate in the pipeline at time t, p t is the pressure on the pipeline at time t;

[0011] Q4: Using the slurry flow rate in the pipeline at different times and the pressure on the pipeline obtained in step Q3, characteristic velocity and characteristic pressure are calculated, and the characteristic pressure, characteristic velocity and velocity distribution are used to determine whether the pipeline is leaking, the time when the leakage occurs, and the leakage location.

[0012] Preferably, in step Q1, the specific process of establishing the axial flow model of the slurry in the basic pipe section is as follows:

[0013] Only the slurry flows along the axial direction of the pipeline, so the forces on the slurry in the radial and circumferential directions of the pipeline are ignored. The net force F on the slurry in the axial direction of the pipeline is z Calculated by the following formula:

[0014] (1)

[0015] In the formula, F z is the net force on the slurry in the axial direction of the conveying pipeline, in N; r is the coordinate of the conveying pipeline in the radial direction, in m; θ is the radian coordinate of the conveying pipeline in the circumferential direction, in rad; z is the axial coordinate of the conveying pipeline, in m; τ rz It is the shear stress of the slurry acting on the rz plane, parallel to the radial direction of the conveying pipeline, in N / m 2 ; τ θz It is the shear stress of the slurry acting on the θ-z plane, parallel to the circumferential direction of the conveying pipeline, in N / m 2 ; σ zz It is the direct stress of slurry in the axial direction of the conveying pipeline, in N / m 2 ; Δr represents the coordinate change in the radial direction of the delivery pipeline; Δθ represents the radian coordinate change in the circumferential direction of the delivery pipeline; Δz represents the axial coordinate change of the delivery pipeline;

[0016] Since the pressure on the slurry decreases in the direction of its flow, the net pressure of the slurry in the axial direction of the conveying pipeline is calculated by the following formula:

[0017] (2)

[0018] Where P z is the net pressure on the slurry in the axial direction of the conveying pipeline, in Pa; p is the pressure on the slurry fluid, in Pa;

[0019] Since only the flow of slurry in the axial direction of the conveying pipeline is considered, the net momentum of the slurry in the radial and circumferential directions of the conveying pipeline is ignored. The net momentum of the slurry in the axial direction of the conveying pipeline is calculated by the following formula:

[0020] (3)

[0021] In the formula, MM z is the net momentum of the slurry in the axial direction of the conveying pipeline, in kg·m / s; ρ is the slurry density, in kg / m 3 ; u is the velocity of the slurry fluid in the radial direction of the conveying pipeline, in m / s; v is the velocity of the slurry fluid in the circumferential direction of the conveying pipeline, in m / s; w is the velocity of the slurry fluid in the axial direction of the conveying pipeline, in m / s;

[0022] r does not change with the change of z, and the net change rate of the momentum of the slurry in the basic pipe section is calculated by the following formula:

[0023] (4)

[0024] Where M t It is the net rate of change of the axial momentum of the slurry along the conveying pipeline in the basic pipe section, in kg·m / s;

[0025] The gravity component G of the slurry in the axial direction of the conveying pipeline z Calculated by the following formula:

[0026] (5)

[0027] In the formula, G z It is the component of gravity of the slurry in the axial direction of the conveying pipeline, in N; g z It is the acceleration component of the slurry gravity along the axial direction of the conveying pipeline, in m / s 2 ;

[0028] Applying Newton's first law of motion, the axial flow model of the slurry in the basic pipe section is determined and expressed as:

[0029] (6)

[0030] Where t is time, unit is s.

[0031] Preferably, in step Q2, the leakage factor K is first calculated by the following formula: L :

[0032] (7)

[0033] Where, Q1 is the slurry flow rate at the inlet of the pipeline, in t / day; Q2 is the slurry flow rate at the outlet of the pipeline, in t / day;

[0034] The leakage factor K L Introducing formula (6), the leakage diagnosis model of slurry transportation pipeline is established, which is expressed as:

[0035] (8).

[0036] Preferably, in step Q3, the standard k-ε turbulence model consists of a turbulence energy equation and a turbulence dissipation rate equation, wherein the turbulence energy equation is:

[0037] (9)

[0038] The turbulent dissipation rate equation is:

[0039] (10)

[0040] Where k is the turbulent kinetic energy, in J; μ is the fluid viscosity, in Pa·s; μ t is the turbulent viscosity, in Pa·s; ε is the turbulent dissipation rate; C 1ε =1.44, C 2ε =1.92, C μ =0.09,σ k =1.0,σ ε =1.3 is the empirical constant; G k is the generation term of turbulent kinetic energy k caused by the mean velocity gradient; x i and x j is the spatial coordinate, with subscripts i, j = 1, 2, 3, i ≠ j, representing the x, y, z coordinate axes; u i is the velocity component of the slurry in the i direction; S k and S ε is the source item.

[0041] Preferably, in step Q4, the slurry characteristic velocity is calculated using the following formula:

[0042] (11)

[0043] In the formula, v nis the characteristic velocity; v t 、v t+1 、v t+2 are the slurry flow rates in the pipeline at time t, time t+1, and time t+2 respectively;

[0044] The characteristic pressure of slurry is calculated using the following formula:

[0045] (12)

[0046] In the formula, p n is the characteristic pressure; p t 、p t+1 、p t+2 are the pressures on the pipeline at time t, time t+1, and time t+2 respectively.

[0047] Preferably, in step Q4, the criteria for judging whether the slurry conveying pipeline leaks, the leakage time, and the leakage location are as follows: when the characteristic velocity and the characteristic pressure are zero, the conveying pipeline is in a stable state; when the characteristic velocity and the characteristic pressure are not zero, the conveying pipeline has a leakage phenomenon, and the time point when the characteristic velocity and the characteristic pressure are not zero is the leakage time of the slurry conveying pipeline. L The characteristic velocity distribution shows a distribution slowdown position along the length of the pipeline, indicating that there is a leakage at this position.

[0048] Beneficial effects of the present invention:

[0049] 1. The present invention uses characteristic pressure and characteristic velocity to quickly and accurately judge the pipeline leakage situation, leakage time and leakage location, reduce the interference of external environmental factors (such as temperature, leakage noise, etc.) and leakage slurry on the judgment result during the judgment process, and make the judgment result more accurate.

[0050] 2. In the judgment process of the present invention, the highly turbulent state of the slurry is taken into consideration, so that the process on which the judgment result depends is closer to the actual state, further improving the accuracy of the judgment result.

[0051] 3. The present invention can quickly and accurately diagnose the leakage of the slurry conveying pipeline, provide guidance for the actual slurry conveying situation, and reduce the economic loss, resource waste and environmental pollution caused by the leakage of the slurry conveying pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 The figure is a schematic flow chart of the method for diagnosing leakage in a slurry conveying pipeline according to the present invention.

[0053] Figure 2 Schematic diagram of the model framework of the present invention.

[0054] Figure 3This is the graph of pipeline characteristic velocity changing with time under fault conditions.

[0055] Figure 4 This is the graph of pipeline characteristic pressure changing with time under fault conditions.

[0056] Figure 5 Under fault conditions, different leakage factors K L Velocity distribution along the pipe section. DETAILED DESCRIPTION

[0057] The present invention is further described in detail below in conjunction with specific embodiments.

[0058] The present invention takes a certain slurry conveying pipeline network as an example, and the parameters of each pipe section of the slurry conveying pipeline network are shown in Table 1.

[0059] Table 1

[0060] Pipe segment <![CDATA[Flow rate (10 3 t / day)]]> Pipe diameter (mm) Speed ​​(m / s) Length (m) Pipe roughness S1 189.36 400 1.19 45870 0.05 S2 189.36 400 1.19 45870 0.05 S3 168.36 400 1.06 18970 0.05 S4 127.91 400 1.16 16640 0.05 S5 52.85 400 0.48 9450 0.05 S6 52.85 300 0.75 9450 0.05

[0061] The S1 pipe segment is diagnosed through the following process:

[0062] (1) Establish the axial flow model of slurry in the basic pipe section:

[0063] Only the slurry flows along the axial direction of the pipeline, so the forces on the slurry in the radial and circumferential directions of the pipeline are ignored. The net force F on the slurry in the axial direction of the pipeline is z Calculated by the following formula:

[0064] (1)

[0065] In the formula, F z is the net force on the slurry in the axial direction of the conveying pipeline, in N; r is the coordinate of the conveying pipeline in the radial direction, in m; θ is the radian coordinate of the conveying pipeline in the circumferential direction, in rad; z is the axial coordinate of the conveying pipeline, in m; τ rz It is the shear stress of the slurry acting on the rz plane, parallel to the radial direction of the conveying pipeline, in N / m 2 ; τ θz It is the shear stress of the slurry acting on the θ-z plane, parallel to the circumferential direction of the conveying pipeline, in N / m 2 ; σ zz is the direct stress of the slurry in the axial direction of the conveying pipeline, in N / m 2 ; Δr represents the coordinate change in the radial direction of the delivery pipeline; Δθ represents the radian coordinate change in the circumferential direction of the delivery pipeline; Δz represents the axial coordinate change of the delivery pipeline;

[0066] Since the pressure on the slurry decreases in its flow direction, the net pressure of the slurry in the axial direction of the conveying pipeline is calculated by the following formula:

[0067] (2)

[0068] Where P z is the net pressure on the slurry in the axial direction of the conveying pipeline, in Pa; p is the pressure on the slurry fluid, in Pa;

[0069] Since only the flow of slurry in the axial direction of the conveying pipeline is considered, the net momentum of the slurry in the radial and circumferential directions of the conveying pipeline is ignored. The net momentum of the slurry in the axial direction of the conveying pipeline is calculated by the following formula:

[0070] (3)

[0071] In the formula, MM z is the net momentum of the slurry in the axial direction of the conveying pipeline, in kg·m / s; ρ is the slurry density, in kg / m 3 ; u is the velocity of the slurry fluid in the radial direction of the conveying pipeline, in m / s; v is the velocity of the slurry fluid in the circumferential direction of the conveying pipeline, in m / s; w is the velocity of the slurry fluid in the axial direction of the conveying pipeline, in m / s.

[0072] r does not change with the change of z, and the net change rate of the momentum of the slurry in the basic pipe section is calculated by the following formula:

[0073] (4)

[0074] Where M t It is the net rate of change of the axial momentum of the slurry along the conveying pipeline in the basic pipe section, and the unit is kg·m / s.

[0075] The gravity component G of the slurry in the axial direction of the conveying pipeline z Calculated by the following formula:

[0076] (5)

[0077] In the formula, G z It is the component of gravity of the slurry in the axial direction of the conveying pipeline, in N; g z It is the acceleration component of the slurry gravity along the axial direction of the conveying pipeline, in m / s 2 .

[0078] Applying Newton's first law of motion, the axial flow model of the slurry in the basic pipe section is determined and expressed as:

[0079] (6)

[0080] Where t is time, unit is s.

[0081] (2) Establishment of leakage diagnosis model for slurry pipeline:

[0082] First, calculate the leakage factor K by the following formula L :

[0083] (7)

[0084] Where Q1 is the slurry flow rate at the inlet of the pipeline, in t / day; Q2 is the slurry flow rate at the outlet of the pipeline, in t / day.

[0085] The leakage factor K L Introducing formula (6), the leakage diagnosis model of slurry transportation pipeline is established, which is expressed as:

[0086] (8).

[0087] The leakage factor calculation results are shown in Table 2.

[0088] (3) Using ANSYS Fluent software to solve the slurry pipeline leakage diagnosis model and the standard k-ε turbulence model:

[0089] The standard k-ε turbulence model consists of the turbulent energy equation (k equation) and the turbulent dissipation rate equation (ε equation), where the turbulent energy equation is:

[0090] (9)

[0091] The turbulent dissipation rate equation is:

[0092] (10)

[0093] Where k is the turbulent kinetic energy, in J; μ is the fluid viscosity, in Pa·s; μ t is the turbulent viscosity, in Pa·s; ε is the turbulent dissipation rate; C 1ε =1.44, C 2ε =1.92, C μ =0.09,σ k =1.0,σ ε =1.3 is the empirical constant; G k is the generation term of turbulent kinetic energy k caused by the mean velocity gradient; x i and x j is the spatial coordinate, with subscripts i, j = 1, 2, 3, i ≠ j, representing the x, y, z coordinate axes; u iis the velocity component of the slurry in the i direction; S k and S ε is the source item.

[0094] (4) Calculate characteristic velocity and characteristic pressure:

[0095] The slurry characteristic velocity is calculated using the following formula:

[0096] (11)

[0097] In the formula, v n is the characteristic velocity; v t 、v t+1 、v t+2 are the slurry flow rates in the pipeline at time t, time t+1, and time t+2 respectively;

[0098] The characteristic pressure of slurry is calculated using the following formula:

[0099] (12)

[0100] In the formula, p n is the characteristic pressure; p t 、p t+1 、p t+2 are the pressures on the pipeline at time t, time t+1, and time t+2 respectively.

[0101] In this embodiment, the calculated characteristic velocity changes with time as shown in the figure Figure 3 The characteristic pressure changes with time as shown in Figure 4 As shown, different leakage factors K L The velocity distribution along the pipeline section is as follows Figure 5 shown.

[0102] pass Figure 3 It can be seen that the characteristic velocity is negative at 0.22-0.81min, and the minimum characteristic velocity appears at 0.6min, which is -30, indicating that there is a leak in the pipeline; then the characteristic velocity fluctuates between 1.2-1.4min, and then after 2.06min, the characteristic velocity suddenly drops, indicating that another leak has occurred. Figure 4 It can be seen that between 0.21 and 0.78 minutes, the characteristic pressure is positive, indicating that there is a leak in the pipeline; between 0.81 and 2.0 minutes, the characteristic pressure fluctuates, and at 2.06 minutes, the characteristic pressure suddenly increases, indicating that the pipeline has leaked again. The error between the characteristic velocity and the characteristic pressure at the time point of the leak is small and within a reasonable range. The method of the present invention can reasonably and effectively determine the pipeline leakage and the leakage time.

[0103] pass Figure 5It can be seen that as the leakage factor K L As the leakage factor K increases, the velocity distribution increases along the length of the pipeline. The velocity distribution slows down at 3 m. Above 3 m, the velocity distribution decreases with the increase of the leakage factor K. L The velocity continues to increase, indicating that there is a leak in the pipeline at a distance of 3m from the pipeline inlet.

[0104] Based on the above judgment results, there is leakage in the S1 pipe section. Therefore, the leakage slurry flow Q can be calculated by the following formula: L , Leak hole diameter D L .

[0105]

[0106] In the formula, Q L is the leakage slurry flow rate, in t / day; Q1 is the slurry flow rate at the pipeline inlet, in t / day; Q2 is the slurry flow rate at the pipeline outlet, in t / day.

[0107]

[0108] Where D L is the diameter of the leak hole, in cm; v L is the slurry flow rate at the leakage location, in m / s.

[0109] Leakage slurry flow rate Q L , leakage hole diameter D L The calculation results are shown in Table 2.

[0110] Table 2

[0111] Serial number <![CDATA[Leakage factor K L > <![CDATA[Leakage flow rate Q L (10 3 t / day)]]> <![CDATA[Leakage hole diameter D L (cm)]]> <![CDATA[Import flow rate Q1 (10 3 t / day)]]> <![CDATA[Outlet flow rate Q2 (10 3 t / day)]]> <![CDATA[Leakage velocity v L (m / s)]]> 1 0.019 3.53 3.30 189.36 185.83 3.9 2 0.109 20.581 7.96 189.36 168.779 3.9 3 0.113 21.447 8.12 189.36 167.913 3.9 4 0.268 50.752 12.50 189.36 138.608 3.9 5 0.336 63.555 13.98 189.36 125.805 3.9 6 0.393 74.394 15.13 189.36 114.966 3.9 7 0.430 81.435 15.83 189.36 107.925 3.9 8 0.509 96.47 17.23 189.36 92.89 3.9 9 0.528 99.957 17.54 189.36 89.403 3.9 10 0.655 124.042 19.54 189.36 65.318 3.9

[0112] From Table 2, we can see that the leakage factor K L Diameter D of pipeline leakage hole L and leakage flow Q L With the leakage factor K L From 0.019 to 0.655, the leakage flow Q L Increased by 97.2%, the leakage hole diameter D L Increased from 3.3cm to 19.54cm. This indicates that the diameter of the pipeline leakage hole D L and leakage flow Q L Leakage factor K L Therefore, after judging the leakage of the slurry pipeline, the leakage hole diameter and leakage flow rate of the slurry pipeline can be preliminarily judged according to the leakage factor, so as to arrange remedial measures reasonably.

[0113] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for diagnosing leakage in a slurry conveying pipeline, characterized in that: The leak diagnosis method The following steps are involved: Q1: Establish an axial flow model of slurry in a basic pipe section. The basic pipe section is a slurry conveying pipeline that is infinitely subdivided, and the smallest unit of the pipeline is the basic pipe section; The specific process of establishing the axial flow model of slurry in the basic pipe section is as follows: Only the slurry flows along the axial direction of the pipeline, so the forces on the slurry in the radial and circumferential directions of the pipeline are ignored. The net force F on the slurry in the axial direction of the pipeline is z Calculated by the following formula: In the formula, F z is the net force on the slurry in the axial direction of the conveying pipeline, in N; r is the coordinate of the conveying pipeline in the radial direction, in m; θ is the arc coordinate of the conveying pipeline in the circumferential direction, in rad; z is the axial coordinate of the conveying pipeline, in m; τ rz It is the shear stress of the slurry acting on the rz plane, parallel to the radial direction of the conveying pipeline, in N / m 2 ; τ θz It is the shear stress of the slurry acting on the θ-z plane, parallel to the circumferential direction of the conveying pipeline, in N / m 2 ; σ zz is the direct stress of the slurry in the axial direction of the conveying pipeline, in N / m 2 ; Δr represents the coordinate change in the radial direction of the delivery pipeline; Δθ represents the radian coordinate change in the circumferential direction of the delivery pipeline; Δz represents the axial coordinate change of the delivery pipeline; Since the pressure on the slurry decreases in its flow direction, the net pressure of the slurry in the axial direction of the conveying pipeline is calculated by the following formula: Where P z is the net pressure on the slurry in the axial direction of the conveying pipeline, in Pa; p is the pressure on the slurry fluid, in Pa; Since only the flow of slurry in the axial direction of the conveying pipeline is considered, the net momentum of the slurry in the radial and circumferential directions of the conveying pipeline is ignored. The net momentum of the slurry in the axial direction of the conveying pipeline is calculated by the following formula: In the formula, MM z is the net momentum of the slurry in the axial direction of the conveying pipeline, in kg·m / s; ρ is the slurry density, in kg / m 3 ; u is the velocity of the slurry fluid in the radial direction of the conveying pipeline, in m / s; v is the velocity of the slurry fluid in the circumferential direction of the conveying pipeline, in m / s; w is the velocity of the slurry fluid in the axial direction of the conveying pipeline, in m / s; r does not change with the change of z, and the net change rate of the momentum of the slurry in the basic pipe section is calculated by the following formula: Where M t It is the net rate of change of the axial momentum of the slurry along the conveying pipeline in the basic pipe section, in kg·m / s; The gravity component G of the slurry in the axial direction of the conveying pipeline z Calculated by the following formula: G z =ρg z △rΔθ△z (5) In the formula, G z It is the component of gravity of the slurry in the axial direction of the conveying pipeline, in N; g z It is the acceleration component of the slurry gravity along the axial direction of the conveying pipeline, in m / s 2 ; Applying Newton's first law of motion, the axial flow model of the slurry in the basic pipe section is determined by equations (1)-(5), which is expressed as: Where, t is time, unit is s; Q2: Calculate the leakage factor K L , and the leakage factor K L Introducing the axial flow model established in step Q1 to establish a slurry conveying pipeline leakage diagnosis model; First, calculate the leakage factor K by the following formula L : Where, Q1 is the slurry flow rate at the inlet of the pipeline, in t / day; Q2 is the slurry flow rate at the outlet of the pipeline, in t / day; The leakage factor K L Introducing formula (6), the leakage diagnosis model of slurry transportation pipeline is established, which is expressed as: Q3: Use ANSYS Fluent software to solve the slurry pipeline leakage diagnosis model obtained in step Q2 and the standard k-ε turbulence model to obtain the slurry flow velocity v in the pipeline at different times t And the pipeline pressure p t , where v t is the slurry flow rate in the pipeline at time t, p t is the pressure on the pipeline at time t; Q4: Using the slurry flow rate in the pipeline at different times and the pressure on the pipeline obtained in step Q3, characteristic velocity and characteristic pressure are calculated, and the characteristic pressure, characteristic velocity and velocity distribution are used to determine whether the pipeline is leaking, the time when the leakage occurs, and the leakage location.

2. A method for diagnosing leakage in a slurry conveying pipeline according to claim 1, characterized in that: In step Q3, the standard k-ε turbulence model consists of a turbulent energy equation and a turbulent dissipation rate equation, wherein the turbulent energy equation is: The turbulent dissipation rate equation is: Where k is the turbulent kinetic energy, in J; μ is the fluid viscosity, in Pa·s; μ t is the turbulent viscosity, in Pa·s; ε is the turbulent dissipation rate; C 1ε =1.44, C 2ε =1.92, C μ =0.09,σ k =1.0,σ ε =1.3 is the empirical constant; G k is the generation term of turbulent kinetic energy k caused by the mean velocity gradient; x i and x j is the spatial coordinate, with subscripts i, j = 1, 2, 3, i ≠ j, representing the x, y, z coordinate axes; u i is the velocity component of the slurry in the i direction; S k and S ε is the source item.

3. A method for diagnosing leakage of a slurry conveying pipeline according to claim 1, characterized in that: In step Q4, the slurry characteristic velocity is calculated using the following formula: In the formula, v n is the characteristic speed; v t 、v t+1 、v t+2 are the slurry flow rates in the pipeline at time t, time t+1, and time t+2 respectively; The characteristic pressure of slurry is calculated using the following formula: In the formula, p n is the characteristic pressure; p t 、p t+1 、p t+2 are the pressures on the pipeline at time t, time t+1, and time t+2 respectively.

4. A method for diagnosing leakage in a slurry conveying pipeline according to claim 1, characterized in that: In step Q4, the criteria for judging whether the slurry conveying pipeline leaks, the leakage time, and the leakage location are as follows: when the characteristic velocity and the characteristic pressure are zero, the conveying pipeline is in a stable state; when the characteristic velocity and the characteristic pressure are not zero, the conveying pipeline has a leakage phenomenon, and the time point when the characteristic velocity and the characteristic pressure are not zero is the leakage time of the slurry conveying pipeline. L The characteristic velocity distribution shows a slowing trend along the length of the pipeline, indicating that there is a leakage at this location.

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