Method for calculating on-way concentration distribution of mud conveying pipeline of cutter suction dredger

Abstract

The invention relates to a method for calculating the on-way concentration distribution of a mud conveying pipeline of a cutter suction dredger, and the method comprises the following steps: S1, collecting mud density and flow velocity data in real time, and carrying out the real-time filtering processing and storage of the data; s2, the mud conveying pipeline is segmented according to different pipeline characteristics, and initial parameters of each segment of the mud conveying pipeline are set; s3, calculating the concentration distribution of each section of sludge conveying pipeline by adopting a concentration conveying equation, and simultaneously considering the influence of friction and pressure loss on the flow velocity; s4, the flow velocity and the concentration are updated in a loop iteration mode according to the set time step length, the equation is solved through a finite difference method, and then the slurry on-way concentration distribution value of the whole slurry conveying pipeline is obtained; and S5, visually displaying the on-way concentration distribution condition of the whole sludge conveying pipeline according to a calculation result. According to the method, the concentration distribution condition of the cutter suction dredger mud conveying pipeline can be accurately calculated and displayed in real time, the dredging construction efficiency and precision are effectively improved, the pipe blocking risk is reduced, and the construction safety is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of engineering ship automation, and particularly relates to a method for calculating the along - line concentration distribution of the mud conveying pipeline of a cutter suction dredger. Background Art

[0002] During the dredging construction process of a cutter suction dredger, the slurry is sucked from the dredging point into the dredging construction ship and transported through a long - distance pipeline to a designated mud pond or treatment facility. Usually, this transportation distance can reach several kilometers or even more than ten kilometers. Since the flow conditions of the slurry in the pipeline (such as flow velocity and concentration) are dynamically changing, and the slurry transportation usually involves pipelines with different diameters and lengths (such as on - ship pipes, underwater pipes, above - water pipes, land pipes, etc.), this leads to significant non - uniformity in the density distribution of the slurry in the pipeline.

[0003] This non - uniformity may bring a series of serious problems. For example, when the concentration of solid particles in the slurry is too high, it is very easy to form accumulations in some areas of the pipeline, which may further lead to the blockage of the mud conveying pipeline. The non - uniform slurry concentration will also cause increased wear of the pump and pipeline, thus triggering failures of the pipeline and equipment. This not only increases the equipment maintenance cost but also may bring unforeseen safety hazards. Therefore, during the construction process, the real - time monitoring of the concentration distribution in the mud conveying pipeline becomes crucial. Summary of the Invention

[0004] Aiming at the problems existing in the prior art, the present invention provides a method for calculating the along - line concentration distribution of the mud conveying pipeline of a cutter suction dredger. The method first obtains the slurry density and flow velocity data measured by a density meter and a flow velocity flowmeter, and performs real - time processing and storage of the data. Then, according to the different pipeline characteristics, the mud conveying pipeline is segmented (including on - ship pipes, underwater pipes, above - water pipes, land pipes, etc.), and the initial parameters of each segment are set (including pipe diameter, particle settling velocity, friction factor, etc.); Next, the concentration transport equation is used to calculate the concentration distribution of each segment, while considering the influence of friction and pressure loss on the flow velocity, and the flow velocity and concentration are cyclically iteratively updated according to the set time step; Finally, the equation is solved by the finite - difference method to obtain the along - line concentration distribution value of the slurry in the entire pipeline, and it is visually displayed in the software of the dredging integrated monitoring system.

[0005] The present invention is implemented as follows. A method for calculating the along - line concentration distribution of the mud conveying pipeline of a cutter suction dredger includes the following steps: S1. Real - time collect the slurry density and flow velocity data, and perform real - time filtering processing and storage of the data; S2. Segment the mud conveying pipeline according to different pipeline characteristics, and set the initial parameters of each segment of the mud conveying pipeline; S3. Use the concentration transport equation to calculate the concentration distribution of each segment of the mud conveying pipeline, while considering the influence of friction and pressure loss on the flow velocity; S4. Iteratively update the flow velocity and concentration according to the set time step, and use the finite difference method to solve the equation, thereby obtaining the distribution value of the mud concentration along the entire mud conveying pipeline; S5. Visualize and display the distribution of the concentration along the entire mud conveying pipeline according to the calculation results.

[0006] Preferably, in step S1, the real-time acquisition is completed through the data acquisition module of the ship's dredging integrated monitoring system, the data acquisition period is 200 milliseconds to 1 second, and the mud density and flow velocity data are respectively obtained by collecting the data of the densitometer and the flow velocity flowmeter installed on the ship's mud conveying pipeline.

[0007] Preferably, in step S1, the real-time filtering process refers to using the Gaussian filtering algorithm and the extreme value filtering algorithm for data processing.

[0008] Preferably, in step S2, the segmentation of the mud conveying pipeline according to different pipeline characteristics means dividing the mud conveying pipeline into four types: the on-board pipeline, the above-water pipeline, the underwater pipeline, and the land pipeline.

[0009] Preferably, in step S2, the initial parameters of each section of the mud conveying pipeline include the pipeline diameter, the pipeline length, the particle settling velocity, the pipeline friction factor, the mud diffusion coefficient, the water density, and the mud saturation density.

[0010] Further preferably, the parameter data of the particle settling velocity, the pipeline friction factor, the mud diffusion coefficient, and the mud saturation density in the initial parameters are obtained by collecting soil samples at the construction site and then analyzing and testing them in a professional laboratory, or by querying relevant engineering manuals and standards.

[0011] Preferably, in step S3, the concentration transport equation is as follows: (1) In the formula: represents the position of the mud along the pipeline length, with the unit of m; represents time, with the unit of s; C is the mud mass concentration, which varies with the position and time , with the unit of ; represents the flow velocity that varies with the position , with the unit of m / s; is the mud diffusion coefficient, representing the diffusion effect of the mud in the pipeline, with the unit of ; is the particle settling velocity, representing the settling velocity of the mud particles in the pipeline, with the unit of m / s.

[0012] Preferably, in step S3, considering the influence of friction and pressure loss on the flow rate means that when the slurry is transported in the sludge pipeline, the friction between the slurry and the pipe wall and the viscous effect of the slurry cause pressure loss, thereby affecting the flow rate and concentration change; Among them, the pressure loss formula is as follows: (2) In the formula: represents the pressure loss, with the unit of Pa; represents the pipeline friction factor; represents the slurry density, with the unit of ; represents the flow rate, with the unit of m / s; L represents the pipeline length, with the unit of m; D represents the pipeline diameter, with the unit of m.

[0013] Preferably, in step S4, the time step refers to the set data acquisition period, and it is calculated once for each data acquisition period.

[0014] Preferably, in step S4, the cyclic iterative update of the flow rate and concentration is calculated as follows: First, determine the pipeline diameter, pipeline length, initial inlet flow rate, and pipeline friction factor of each section of the pipeline according to the pipeline segmentation situation; among them, the initial inlet flow rate of the on-board pipeline adopts the flow rate after real-time acquisition and processing, and the initial inlet flow rate of each subsequent section of the pipeline respectively adopts the outlet flow rate of its previous section of the pipeline; considering that the slurry is incompressible and the influence of the change in pipeline diameter on the flow rate, the following formula is used to calculate the flow rate change caused by the change in pipeline diameter: (3) In the formula: represents the initial inlet flow rate of the subsequent section of the pipeline, with the unit of m / s; represents the pipeline diameter of the subsequent section of the pipeline, with the unit of m; represents the outlet flow rate of the previous section of the pipeline, with the unit of m / s; represents the pipeline diameter of the previous section of the pipeline, with the unit of m.

[0015] Further preferably, after determining the initial inlet flow rate of each section of the pipeline, perform cyclic iterative calculations on all the acquisition data that flows into and does not flow out of each section of the pipeline according to the flow rate situation of the slurry, and calculate the distance that the slurry flows in each time step, and the formula is as follows: (4) In the formula: represents the position along the length of each section of the pipeline The distance that the slurry flows in one time step at the position is m; represents the position along the length of each section of the pipeline The flow velocity of the mud at [location], in m / s; represents the time step, in s.

[0016] Further preferably, during the iterative calculation process, the position of the mud along the pipeline length in each current time step is calculated according to the following formula: (5) In the formula: represents the iterative step n , the position of the mud at the position along each pipeline length, in m; represents the iterative step n , the flow velocity of the mud at the position along each pipeline length, in m / s; represents the time step, in s.

[0017] Further preferably, during the iterative calculation process, according to formula (2), combining the distance, flow velocity, mud density, pipeline friction factor, and pipeline diameter of the mud flow in each time step, the pressure loss is calculated and the formula for updating the flow velocity is as follows: (6) In the formula: represents the iterative step n, the flow velocity of the mud at the position along each pipeline length, in m / s; represents the pipeline friction factor; represents the mud density, in ; represents the iterative step n , the distance of the mud flow at the position along each pipeline length, in m; represents the pipeline diameter, in m.

[0018] Further preferably, the formula for converting the real-time collected mud density into mud mass concentration is as follows: (7) In the formula: represents the mud mass concentration used in formula (1), in ; represents the mud density, in ; represents the water density set in the initial parameters, in .

[0019] Further preferably, during the cyclic iterative calculation process, according to the calculation results of the above formulas (5) and (6), the formula (1) is solved by the finite difference method to obtain the following formula, and then the mud along - the - line concentration distribution value of the entire pipeline is calculated: (8) In the formula: represents the cyclic iteration step n, and the mud mass concentration at the position along each pipeline length is in the unit of ; represents the mud mass concentration at the position -1 along each pipeline length in the cyclic iteration step n, and the unit is ; represents the mud mass concentration at the position +1 along each pipeline length in the cyclic iteration step n, and the unit is ; represents the cyclic iteration step n , and the flow velocity of the mud at the position along each pipeline length is in the unit of m / s; represents the cyclic iteration step n , and the distance that the mud flows at the position along each pipeline length is in the unit of m; represents the time step length, and the unit is s; is the mud diffusion coefficient, and the unit is ; is the particle settling velocity, and the unit is m / s.

[0020] Preferably, in step S5, the visual display takes the pipeline length as the abscissa and the mud mass percentage concentration as the ordinate to plot the concentration change and distribution of the entire mud - conveying pipeline.

[0021] Further preferably, the calculation formula for converting the mud mass concentration to the mud mass percentage concentration is as follows: (9) In the formula: represents the mud mass percentage concentration, and the unit is %; C represents the mud mass concentration, and the unit is ; represents the water density set in the initial parameters, and the unit is ; represents the saturated density of the mud set in the initial parameters, and the unit is .

[0022] The advantages and positive effects of the present invention are: 1. The present invention solves the problem that dredging construction personnel cannot accurately and real - time master the distribution of mud in the mud - conveying pipeline by using real - time collected data such as mud density and flow velocity, and combining parameters such as different pipeline characteristics and their corresponding pipeline diameters, pipeline lengths, particle settling velocities, pipeline friction factors, mud diffusion coefficients, water density, and mud saturation density. By using the concentration transport equation, considering the influence of friction and pressure loss on flow velocity, and comprehensively utilizing technologies such as computers, networks, sensors, and automation, the safety and construction efficiency of dredging construction are greatly improved.

[0023] 2. The present invention helps dredging construction personnel accurately understand the dynamic distribution of mud in the pipeline by real - time monitoring and calculating the mud concentration distribution in the mud - conveying pipeline of a cutter suction dredger, making early predictions and timely optimizing construction parameters, preventing pipeline blockages, reducing equipment wear, and improving construction safety and efficiency. In this way, the efficient and safe operation of dredging construction can be ensured, and the overall efficiency and reliability of dredging projects can be further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the pipeline sectioning and equipment installation positions of the mud - conveying pipeline of the cutter suction dredger provided by the embodiment of the present invention; Figure 2 is a flowchart of the method for calculating the along - line concentration distribution of the mud - conveying pipeline of the cutter suction dredger provided by the embodiment of the present invention; Figure 3 is a schematic diagram of the visualization display of the along - line concentration distribution of the mud - conveying pipeline of the cutter suction dredger provided by the embodiment of the present invention.

[0025] In the figure: 1. Density meter; 2. Flow velocity flowmeter; 3. On - ship pipeline; 4. Above - water pipeline; 5. Under - water pipeline; 6. Land pipeline. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] In order to further understand the content, features, and effects of the present invention, the following embodiments are cited. The present invention will be described in detail below in combination with specific embodiments and drawings. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can be made. These all fall within the protection scope of the present invention.

[0027] A method for calculating the along - line concentration distribution of the mud - conveying pipeline of a cutter suction dredger provided by the embodiment of the present invention, the pipeline sectioning, equipment, and their installation positions are as Figure 1 shown. The pipeline sectioning distribution is the on - ship pipeline 3, the above - water pipeline 4, the under - water pipeline 5, and the land pipeline 6; the equipment includes: a density meter 1 and a flow velocity flowmeter 2. Among them, the density meter 1 uses a radioactive density meter or an electrical density meter, and the flow velocity flowmeter 2 uses an electromagnetic flowmeter.

[0028] The flow velocity flowmeter 2 is installed in the form of a short joint on the sludge pipeline of the ship, and the density meter 1 is directly nested outside the flow velocity flowmeter 2 for installation, or the installation distance between the flow velocity flowmeter 2 and the density meter 1 is within 1 meter.

[0029] Such as Figure 2 As shown, a method for calculating the concentration distribution along the sludge pipeline of a cutter suction dredger provided by an embodiment of the present invention is implemented as follows: S1. Real-time collect the slurry density and flow velocity data, and perform real-time filtering processing and storage on the data; Among them, the density value is obtained by collecting the data of the density meter, and the flow velocity value is obtained by collecting the data of the electromagnetic flowmeter.

[0030] The real-time collection is completed by the data collection module of the ship's dredging integrated monitoring system, and the data collection period is set to 200 milliseconds to 1 second.

[0031] The real-time filtering processing refers to using the Gaussian filtering algorithm and the extreme value filtering algorithm for data processing, and at the same time storing the data processed in each data collection period. Among them, the extreme value filtering algorithm presets extreme values, including the minimum slurry density, the maximum slurry density, the minimum flow velocity, and the maximum flow velocity. If it exceeds the maximum and minimum boundary value ranges, it is judged as abnormal data and directly discarded. In this example, the minimum slurry density is set to 1000 , the maximum slurry density is set to 2000 ; the minimum flow velocity is set to 0 m / s, the maximum flow velocity is set to 10 m / s; in this example, the data collection period is set to 200 milliseconds.

[0032] S2. Segment the sludge pipeline according to different pipeline characteristics, and set the initial parameters of each section of the sludge pipeline.

[0033] The sludge pipeline is segmented according to different pipeline characteristics. In this example, the sludge pipeline is divided into four types: on-board pipeline, above-water pipeline, underwater pipeline, and land pipeline.

[0034] The initial parameters of each section of the sludge pipeline. In this example, the set initial parameters include pipeline diameter, pipeline length, particle settling velocity, pipeline friction factor, slurry diffusion coefficient, water density, and slurry saturation density. Among them, the parameter data of the particle settling velocity, pipeline friction factor, slurry diffusion coefficient, and slurry saturation density are obtained by collecting soil samples at the construction site and then analyzing and testing them in a professional laboratory.

[0035] S3. Calculate the concentration distribution of each section of the sludge pipeline by using the concentration transport equation, and at the same time consider the influence of friction and pressure loss on the flow velocity.

[0036] The concentration transport equation is as follows: (10) In the formula: represents the position of the mud along the pipeline length, with the unit of m; represents time, with the unit of s; C is the mud mass concentration, varying with the position and time changing, with the unit of ; represents the flow velocity varying with the position changing, with the unit of m / s; is the mud diffusion coefficient, representing the diffusion effect of the mud in the pipeline, with the unit of ; is the particle settling velocity, representing the settling velocity of the mud particles in the pipeline, with the unit of m / s.

[0037] The consideration of the influence of friction and pressure loss on the flow velocity means that when the mud is transported in the mud conveying pipeline, the friction between the mud and the pipe wall and the viscous effect of the mud result in pressure loss, thereby affecting the flow velocity and concentration change. The pressure loss formula is as follows: (11) In the formula: represents the pressure loss, with the unit of Pa; represents the pipeline friction factor; represents the mud density, with the unit of ; represents the flow velocity, with the unit of m / s; L represents the pipeline length, with the unit of m; D represents the pipeline diameter, with the unit of m.

[0038] S4. Iteratively update the flow velocity and concentration according to the set time step, and use the finite difference method to solve the equation, thereby obtaining the mud along - the - way concentration distribution values of the entire mud conveying pipeline.

[0039] The time step refers to the set data acquisition period, and it is calculated once for each data acquisition period. In this example, the data acquisition period is set to 200 ms, so the time step is also 200 ms.

[0040] The flow rate and concentration are updated through cyclic iteration, and the calculation process is as follows: First, determine the pipeline diameter, pipeline length, initial inlet flow rate, and pipeline friction factor of each pipeline section according to the pipeline sectioning of the sludge pipeline. Among them, the initial inlet flow rate of the on-board pipeline adopts the flow rate after real-time acquisition and processing, and the initial inlet flow rate of each subsequent pipeline section respectively adopts the outlet flow rate of its previous pipeline section; Considering that the slurry is incompressible and the influence of the change in pipeline diameter on the flow rate, the following formula is used to calculate the flow rate change caused by the change in pipeline diameter: (12) In the formula: represents the initial inlet flow rate of the subsequent pipeline section, with the unit of m / s; represents the pipeline diameter of the subsequent pipeline section, with the unit of m; represents the outlet flow rate of the previous pipeline section, with the unit of m / s; represents the pipeline diameter of the previous pipeline section, with the unit of m.

[0041] After determining the initial inlet flow rate of each pipeline section, cyclic iteration calculations are performed on all the acquisition data that flows into and does not flow out of each pipeline section according to the flow rate of the slurry, and the distance that the slurry flows in each time step is calculated. The formula is as follows: (13) In the formula: represents the distance that the slurry flows in one time step at the position along the length of each pipeline section , with the unit of m; represents the flow rate of the slurry at the position along the length of each pipeline section , with the unit of m / s; represents the time step, with the unit of s.

[0042] During the cyclic iteration calculation process, the position of the slurry along the pipeline length in each pipeline section at the current time step is calculated using the following formula: (14) In the formula: represents the cyclic iteration step n , and the position of the slurry at the position along the length of each pipeline section , with the unit of m; represents the cyclic iteration step n , and the flow rate of the slurry at the position along the length of each pipeline section , with the unit of m / s; represents the time step, with the unit of s.

[0043] During the cyclic iterative calculation process, according to formula (11), the pressure loss is calculated by combining the distance of mud flow, flow velocity, mud density, pipeline friction factor, and pipeline diameter at each time step, and the calculation formula of the flow velocity is updated as follows: (15) In the formula: represents the cyclic iteration step n, and the flow velocity of the mud at the position along each pipeline length is in m / s; represents the pipeline friction factor; represents the mud density, with the unit of ; represents the cyclic iteration step n , and the distance of mud flow at the position along each pipeline length is in m; represents the pipeline diameter, with the unit of m.

[0044] The above formula (10) uses the mud mass concentration, while the real-time collected data is the mud density. The real-time collected mud density is converted into the mud mass concentration in formula (10), and the calculation formula is as follows: (16) In the formula: represents the mud mass concentration used in formula (10), with the unit of ; represents the mud density, with the unit of ; represents the water density set in the initial parameters, with the unit of .

[0045] During the cyclic iterative calculation process, according to the calculation results of the above formulas (14), (15), and (16), formula (10) is solved by the finite difference method to obtain the following formula, and then the mud along-pipe concentration distribution value of the entire pipeline is calculated.

[0046] (17) In the formula: represents the cyclic iteration step n, and the mud mass concentration at the position along each pipeline length is in ; represents the mud mass concentration at the position along each pipeline length -1 in the cyclic iteration step n, with the unit of ; represents the mud mass concentration at the position along each pipeline length +1 in the cyclic iteration step n, with the unit of ; represents the cyclic iteration stepn , the flow velocity of the slurry at each position along the length of each pipeline section, in m / s; The distance that the slurry flows at each position along the length of each pipeline section, in m; represents the cycle iteration step n , the distance that the slurry flows at each position along the length of each pipeline section The distance that the slurry flows at each position along the length of each pipeline section, in m; represents the time step, in s; is the slurry diffusion coefficient, in ; is the particle settling velocity, in m / s.

[0047] S5. Visualize and display the concentration distribution along the entire mud conveying pipeline according to the calculation results.

[0048] The visualization display plots the concentration change and distribution of the entire mud conveying pipeline with the pipeline length as the abscissa and the mud mass percentage concentration as the ordinate.

[0049] The cutter suction dredger generally uses the mud mass percentage concentration for visualization display. Therefore, in this example, the mud mass concentration is converted to the mud mass percentage concentration, and the conversion formula is as follows: (18) In the formula: represents the mud mass percentage concentration, in %; represents the mud mass concentration, in ; represents the water density set in the initial parameters, in ; represents the saturated density of the slurry set in the initial parameters, in .

[0050] The schematic diagram of the visualization display of the concentration distribution along the mud conveying pipeline of the cutter suction dredger in this example is as shown in Figure 3 shown.

[0051] The present invention greatly solves the problem that dredging construction personnel cannot accurately and real-time master the distribution of slurry in the mud conveying pipeline, realizes the real-time, accurate calculation and visualization display of the mud concentration distribution in the mud conveying pipeline of the cutter suction dredger, improves the safety and control accuracy of dredging construction operation, and further improves the construction efficiency of the cutter suction dredger.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for estimating the concentration distribution along the mud pipeline of a cutter suction vessel, characterized in that: The steps include: S1, real-time collection of mud density and flow rate data, and real-time filtering and storage of the data; S2, dividing the mud pipeline into sections according to different pipeline characteristics, and setting initial parameters of each section of the mud pipeline; S3. Use the concentration transport equation to calculate the concentration distribution of each section of the mud pipeline, while considering the effects of friction and pressure loss on flow rate; S4, iteratively updating the flow rate and concentration according to the set time step, and solving the equation by finite difference method, thereby obtaining the mud concentration distribution value along the entire mud pipeline; S5. Visually display the concentration distribution along the entire mud pipeline based on the calculation results.

2. The method for estimating the concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 1 is characterized in that: In step S1, the real-time acquisition is completed by the data acquisition module of the ship's dredging integrated monitoring system, and the data acquisition cycle is 200 milliseconds to 1 second. The mud density and flow rate data are obtained by collecting data from a density meter and a flow rate flow meter installed on the ship's mud delivery pipeline; The real-time filtering process refers to using Gaussian filtering algorithm and extreme value filtering algorithm to perform data processing.

3. The method for estimating the concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 1 is characterized in that: In step S2, segmenting the mud pipeline according to different pipeline characteristics means dividing the mud pipeline into four types: on-board pipeline, above-water pipeline, underwater pipeline and land pipeline; In step S2, the initial parameters of each section of the mud delivery pipeline include pipeline diameter, pipeline length, particle settling velocity, pipeline friction factor, mud diffusion coefficient, water density and mud saturation density.

4. The method for estimating the concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 3 is characterized in that: The parameter data of particle settling velocity, pipeline friction factor, mud diffusion coefficient and mud saturation density in the initial parameters are obtained by collecting soil samples at the construction site and then analyzing and testing them in a professional laboratory, or by consulting relevant engineering manuals and standards.

5. The method for estimating the concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 1 is characterized in that: In step S3, the concentration transport equation is as follows: （1） Where: Indicates the location of the mud along the length of the pipeline, in m; Indicates time, the unit is s; C is the mud mass concentration, which varies with position and time Change in units of ; Indicates that the position The flow velocity varies with the change, in m / s; is the mud diffusion coefficient, which indicates the diffusion effect of mud in the pipeline, and its unit is ; is the particle settling velocity, which indicates the settling velocity of mud particles in the pipeline, in m / s; The consideration of the influence of friction and pressure loss on flow rate refers to the friction between the mud and the pipe wall and the viscosity effect of the mud causing pressure loss when the mud is transported in the mud pipeline, which in turn affects the flow rate and concentration change; The pressure loss formula is as follows: （2） Where: Indicates pressure loss, unit is Pa; Indicates the pipeline friction factor; Indicates the mud density in units of ; Indicates flow velocity in m / s; L Indicates the length of the pipeline, in meters; D Indicates the pipe diameter in meters.

6. The method for estimating concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 1 is characterized in that: In step S4, the time step refers to a set data collection cycle, and is calculated once per data collection cycle.

7. The method for estimating the concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 5 is characterized in that: In step S4, the flow rate and concentration are updated in a loop iteratively, and the calculation process is as follows: first, the pipeline diameter, pipeline length, initial inlet flow rate, and pipeline friction factor of each section of the pipeline are determined according to the segmentation of the mud pipeline; the initial inlet flow rate of the ship's pipe adopts the flow rate collected and processed in real time, and the initial inlet flow rate of each subsequent section of the pipeline adopts the outlet flow rate of the previous section of the pipeline; considering that the mud is incompressible and the influence of the change of the pipeline diameter on the flow rate, the flow rate change caused by the change of the pipeline diameter is calculated using the following formula: （3） Where: Indicates the initial inlet flow rate of the next section of the pipeline, in m / s; Indicates the diameter of the pipeline in the next section, in meters; Indicates the outlet flow rate of the previous section of the pipeline, in m / s; Indicates the diameter of the previous section of the pipeline, in meters.

8. The method for estimating concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 7, characterized in that: After determining the initial inlet flow rate of each section of the pipeline, all the collected data that flowed into and did not flow out of each section of the pipeline were iteratively calculated according to the flow rate of the mud, and the distance of the mud flow in each time step was calculated. The formula is as follows: （4） Where: Indicates the position along the length of each pipeline The distance that the mud flows in one time step, in meters; Indicates the position along the length of each pipeline The flow rate of the mud at the position, in m / s; Indicates the time step, in seconds.

9. The method for estimating concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 8, characterized in that: During the iterative calculation process, the position of the mud along the length of the pipeline in each section of the pipeline at the current time step is calculated as follows: （5） Where: Represents loop iteration step n , along the length of each pipeline The position of the mud, in m; Represents loop iteration step n , along the length of each pipeline The flow rate of the mud at the position, in m / s; Indicates the time step, in seconds.

10. The method for estimating concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 9, characterized in that: During the iterative calculation process, according to formula (2), the pressure loss is calculated by combining the mud flow distance, flow velocity, mud density, pipeline friction factor and pipeline diameter at each time step, and the calculation formula for the flow velocity is updated as follows: （6） Where: Represents loop iteration step n, along each section of the pipeline length position The flow rate of the mud at the position, in m / s; Indicates the pipeline friction factor; Indicates the mud density in units of ; Represents loop iteration step n , along the length of each pipeline The distance of mud flow at the location, in m; Indicates the pipe diameter in meters.

11. The method for estimating concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 10, characterized in that: The calculation formula for converting the real-time collected mud density into mud mass concentration is as follows: （7） Where: represents the mud mass concentration used in formula (1), in units of ; Indicates the mud density in units of ; Represents the water density of the initial parameter setting, in units of .

12. The method for estimating concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 10, characterized in that: During the iterative calculation process, according to the calculation results of the above formulas (5) and (6), the finite difference method is used to solve formula (1) to obtain the following formula, and then the mud concentration distribution value along the entire pipeline is calculated: （8） Where: Represents loop iteration step n, along each section of the pipeline length position The mass concentration of mud at ; Represents loop iteration step n, along each section of the pipeline length position -1 mud mass concentration, in units of ; Represents loop iteration step n, along each section of the pipeline length position +1 mud mass concentration, unit is ; Represents loop iteration step n , along the length of each pipeline The flow rate of the mud at the position, in m / s; Represents loop iteration step n , along the length of each pipeline The distance of mud flow at the location, in m; Indicates the time step, in seconds; is the mud diffusion coefficient, in units of ; is the particle settling velocity, in m / s.

13. The method for estimating concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 1, characterized in that: In step S5, the visualization is performed by plotting the concentration change and distribution of the entire mud delivery pipeline with the pipeline length as the horizontal coordinate and the mud mass percentage concentration as the vertical coordinate.

14. The method for estimating concentration distribution along the sludge pipeline of a cutter suction vessel according to claim 13, characterized in that: The calculation formula for converting mud mass concentration to mud mass percentage concentration is as follows: （9） Where: Indicates the mud mass percentage concentration, unit is %; Indicates the mud mass concentration in units of ; Represents the water density of the initial parameter setting, in units of ; Indicates the mud saturation density of the initial parameter setting, in units of .

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