Optimized arrangement method, device and system for hydrogen conveying pipeline and storage medium

Abstract

The invention discloses an optimized arrangement method, device and system for a hydrogen conveying pipeline and a storage medium. The optimized arrangement method comprises the steps that S1, an empirical relational expression of the hydrogen jet combustible distance and combustible quality is determined; s2, determining the size and position of an adjacent pipeline, setting a plurality of leakage flows, and constructing a working condition matrix; s3, performing analogue simulation according to the working condition matrix to obtain the combustible mass and the combustible distance of hydrogen, and fitting the combustible distance, the combustible mass and the leakage flow according to an empirical relational expression to obtain a proportionality coefficient; and S4, according to pipeline layout requirements, evaluation is carried out through an empirical relational expression, and a pipeline arrangement mode is optimized. By the adoption of the technical scheme, the problem of potential safety hazards caused by unreasonable arrangement of hydrogen conveying pipelines in an existing hydrogen energy place is solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydrogen safety, and particularly relates to a hydrogen pipeline optimization arrangement method and device, system and storage medium. BACKGROUND

[0002] Hydrogen is a clean and efficient fuel with a wide range of sources and flexible applications, and is widely recognized as one of the most valuable alternative energy sources in this century. With the rapid development of hydrogen energy industry, the number of hydrogen energy facilities such as hydrogen refueling stations, hydrogen production plants and skid-mounted hydrogen energy devices is increasing. As a flammable and explosive gas, the safety of hydrogen has always been the focus of public and industry attention. Hydrogen leakage can easily cause accidents, especially in hydrogen energy places such as hydrogen refueling stations and hydrogen production plants. The arrangement of hydrogen pipelines significantly affects the diffusion characteristics after hydrogen leakage. However, the safety regulations for hydrogen-related places are not perfect, and there is a lack of scientific optimization methods for the arrangement of hydrogen pipelines. Therefore, there is an urgent need for a hydrogen pipeline optimization arrangement method based on safety analysis to improve the safety of hydrogen energy places SUMMARY

[0003] The technical problem to be solved by the present application is to provide a hydrogen pipeline optimization arrangement method and device, system and storage medium, which solves the safety hazard problem caused by unreasonable arrangement of hydrogen pipelines in existing hydrogen energy places. Based on the calculation of flammable distance and flammable mass of hydrogen after leakage under different pipeline arrangement conditions, the present application can be customized and optimized according to the specific scene of the hydrogen energy place, thereby reducing the flammable risk after hydrogen leakage and improving the overall safety of the hydrogen energy place.

[0004] To achieve the above-mentioned purpose, the present application adopts the following technical solution:

[0005] A hydrogen pipeline optimization arrangement method, comprising:

[0006] Step S1, determining an empirical relationship of hydrogen jet flammable distance and flammable mass;

[0007] Step S2, determining the size and position of adjacent pipelines, setting multiple leakage flow rates, and constructing a working condition matrix;

[0008] Step S3, simulating according to the working condition matrix to obtain hydrogen flammable mass and flammable distance, fitting the flammable distance and flammable mass, and leakage flow rate according to the empirical relationship, and obtaining a proportional coefficient;

[0009] Step S4, evaluating according to the empirical relationship and optimizing the pipeline arrangement mode according to the pipeline layout requirements.

[0010] As a preferred, step S1 comprises:

[0011] S11, making reasonable assumptions for the model based on the free jet theory;

[0012] S12, deriving a hydrogen combustible distance and flow rate relationship according to the hypothesis;

[0013] S13, deriving a hydrogen combustible mass and flow rate relationship according to the hypothesis.

[0014] Preferably, step S2 comprises:

[0015] S21, obtaining the size and position of adjacent pipelines in the scene according to the design drawings of the scene, process pipelines and instrument flow charts;

[0016] S22, taking the adjacent pipeline diameter as an optimization object, selecting a plurality of leakage flow rates, and constructing a working condition matrix with the adjacent pipeline diameter;

[0017] Preferably, step S3 comprises:

[0018] S31, using simulation software to simulate the working condition matrix in sections;

[0019] S32, using post-processing software to process the simulation results to obtain the combustible mass and combustible distance;

[0020] S33, fitting the combustible distance and combustible mass, leakage flow rate according to the empirical relationship to obtain the proportional coefficient.

[0021] Preferably, step S4 comprises:

[0022] S41, determining the worst leakage condition according to the size and design working condition of the hydrogen conveying pipeline;

[0023] S42, evaluating according to the empirical relationship according to the pipeline layout requirement, and optimizing the pipeline arrangement mode.

[0024] The application also provides a hydrogen conveying pipeline optimization arrangement device, comprising:

[0025] A first processing module for determining the empirical relationship of hydrogen jet combustible distance and combustible mass;

[0026] A second processing module for determining the size and position of adjacent pipelines, setting a plurality of leakage flow rates, and constructing a working condition matrix;

[0027] A third processing module for simulating according to the working condition matrix to obtain hydrogen combustible mass and combustible distance, fitting the combustible distance and combustible mass, leakage flow rate according to the empirical relationship to obtain the proportional coefficient;

[0028] A fourth processing module for evaluating according to the empirical relationship according to the pipeline layout requirement, and optimizing the pipeline arrangement mode.

[0029] The application further provides a hydrogen pipeline optimal arrangement system, comprising a memory and a processor, wherein the memory stores a computer program which is run by the processor, and the computer program performs the hydrogen pipeline optimal arrangement method when run by the processor.

[0030] The application further provides a storage medium which stores a computer program, and the computer program performs the hydrogen pipeline optimal arrangement method when run.

[0031] Compared with the prior art, the application has the following beneficial effects:

[0032] 1. The application can be customized and optimized according to the pipeline form involved in the hydrogen energy site, thereby reducing the flammable risk after hydrogen leakage and improving the overall safety of the hydrogen energy site.

[0033] 2. The application establishes an empirical relationship between the flammable mass and the flammable distance of the hydrogen jet and the leakage flow rate, and can quickly and accurately calculate the flammable mass and the flammable distance after leakage according to the estimated leakage flow rate.

[0034] 3. The application proposes to use different coefficients to represent the influence of adjacent pipelines on the flammable mass and the flammable distance based on the empirical relationship between the flammable mass and the flammable distance of the hydrogen jet and the leakage flow rate, and can quickly calculate the flammable mass and the flammable distance when the jet impacts the pipeline according to the estimated leakage flow rate.

[0035] 4. The application uses a partitioned and stepped simulation method to greatly improve the calculation efficiency while ensuring the calculation accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0037] Figure 1 The flow chart of the hydrogen pipeline optimal arrangement method of the embodiments of the application;

[0038] Figure 2 The working condition matrix composed of different leakage scales proposed by the application;

[0039] Figure 3 The flow field region division diagram of the calculation model of the application;

[0040] Figure 4 The calculation grid diagram of the near-field region of the application;

[0041] Figure 5 A calculation grid map of a far field zone of the present application;

[0042] Figure 6 A fitting result of flammable mass and leakage flow under different pipeline diameters of the present application;

[0043] Figure 7 A fitting result of flammable distance and leakage flow under different pipeline diameters of the present application; DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0045] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0046] Embodiment 1:

[0047] A hydrogen filling station needs to add a cooling water pipeline around the existing hydrogen pipeline. The cooling water pipeline is arranged in parallel with the hydrogen pipeline, the cooling water pipeline is 100 mm away from the hydrogen pipeline, and the existing cooling water pipeline has a diameter of 8, 15, 20, 25, 30, 35 and 40 mm. The hydrogen pipeline has a diameter of 19.05 mm, a wall thickness of about 4 mm, a design pressure of 10 MPa, and a gas flow rate of 8 m / s. Since there is a hydrogen production workshop in the pipeline arrangement site, it is necessary to ensure that the influence of hydrogen leakage on the hydrogen production workshop is not great. As shown in the table, the present embodiment provides a hydrogen pipeline optimization arrangement method. The leakage flow of the related components of the hydrogen-related site and the diameter of the adjacent pipeline and other parameters are substituted into the built model, and finally the flammable mass and the flammable distance of hydrogen are obtained, thereby providing a scientific basis for the pipeline layout optimization mode of the hydrogen energy site. Specifically, the following steps are included: Figure 1

[0048] S1, determining an empirical relationship of hydrogen jet flammable distance and flammable mass

[0049] S11, model assumption

[0050] (1) Since the hydrogen pressure in the hydrogen pipeline is high, the hydrogen leakage will form a high-pressure under-expanded jet, so the initial momentum of the jet is high, and the influence of buoyancy on the jet is weak, and the jet is a momentum-dominated jet;

[0051] ​(2) The concentration distribution on the jet axis is a hyperbolic distribution, and at a given axial position, the concentration distribution in the jet radial direction is a Gaussian distribution;

[0052] (3) During the process of gas leakage from the inside of the pipeline to the outside, the heat exchange between the air flow and the pipeline and the outside world can be ignored relative to the enthalpy change of hydrogen, that is, the leakage process is approximately an isentropic process.

[0053] S12. Calculation of flammable distance

[0054] The concentration decay of hydrogen jet on the center line of the momentum-dominant region satisfies the hyperbolic decay law, so a certain concentration value Y on the jet axis is s The corresponding axial position z s It can be calculated by the following formula:

[0055]

[0056] Among them, C d is the attenuation coefficient, d e is the leakage hole diameter, ρ e and ρ ∞ are the density of the jet gas at the leak hole outlet and the density of the surrounding air, respectively.

[0057] Hydrogen jet outlet flow rate q m The calculation formula is as follows:

[0058]

[0059] Among them, u e is the velocity at the leak hole outlet, which is the local sound velocity and can be calculated based on the physical parameter relationship of ideal gas or actual gas. Further application of the isentropic expansion relationship can obtain u e The relationship between the temperature of the gas in the tube and T0 is:

[0060]

[0061] That is, the velocity of the jet at the leak hole outlet is only related to the air flow temperature in the pipe. The relationship between the outlet flow rate, gas density and leak hole diameter can be obtained:

[0062]

[0063] Then z s It can be calculated by the following formula:

[0064]

[0065] Among them, C1 is the first proportional coefficient, which is proportional to Y s , ρ ∞ And T0, etc., its expression is:

[0066]

[0067] Here, R represents the universal gas constant.

[0068] When Y s Take the lower flammable limit Y LFL When , the relationship between the flammable distance ME and the flow rate can be obtained:

[0069] ME=C 1,LFL q m 0.5

[0070] Among them, C 1,LFL Represents Y s Take the lower flammable limit Y LFL The value of C1 when .

[0071] S13. Calculation of combustible mass

[0072] The radial concentration of the hydrogen jet satisfies the Gaussian distribution. Assuming that the density of the mixed gas in the calculation area remains unchanged, it is the density of the surrounding air ρ ∞ , then the combustible mass of hydrogen m f The mass of hydrogen between the lower flammable limit LFL and the upper flammable limit UFL can be calculated by the following formula:

[0073]

[0074] Where z represents the axial distance from the nozzle outlet, r represents the radial distance from the jet axis, and r LFL and r UFL are the radial positions corresponding to the lower flammable limit and the upper flammable limit, z LFL and z UFL are the axial positions corresponding to the lower flammable limit and the upper flammable limit, Y cl is the gas mass fraction along the jet centerline, r 0.5 It represents the distance from the position where the hydrogen mass fraction is 1 / 2 of the mass fraction at the jet centerline on the plane to the jet axis on the jet cross section at a certain distance from the nozzle outlet. It can be expressed by r 0.5 =C c z is calculated, C c 、C r are the third and fourth proportional coefficients, respectively, C c 、C r All obtained by fitting.

[0075] The points can be sorted out:

[0076]

[0077] Among them, C2 is the second proportional coefficient, which is related to ρ∞ , Y s and T0, whose expression is:

[0078]

[0079] where Y UFL represents the flammable upper limit of the combustible gas, C 1,UFL represents Y s The value of C1 is taken when the flammable upper limit Y UFL .

[0080] S2, constructing a working condition matrix according to the sizes and positions of adjacent pipelines

[0081] S21, according to the design drawings, process pipelines and instrument flow charts of the scene, obtaining the diameters of the cooling water pipelines available in the scene, which are 8, 15, 20, 25, 30, 35 and 40 mm, and the distance between the cooling water pipeline and the hydrogen pipeline is 100 mm;

[0082] S22, taking the diameter of the cooling water pipeline as the optimization object, selecting multiple leakage flow rates, and constructing a working condition matrix with the diameter of the cooling water pipeline, as shown in Figure 2 .

[0083] S3, fitting the proportionality coefficient of the empirical relationship between the flammable distance and the flammable mass and the leakage flow rate

[0084] S31, geometric model construction

[0085] According to the working condition matrix, a cooling water pipeline is created outside the leakage hole.

[0086] S32, calculation domain division

[0087] Because there is a shock wave within a very short distance outside the leakage hole, the flow parameters change dramatically, and very fine grids need to be created. Outside the shock wave area, the flow parameters change relatively gently, and relatively coarse grids can be used to reduce the total grid amount. Therefore, the calculation area is divided into two parts, the near-field area and the far-field area, and the cooling water pipeline is placed in the far-field area. The geometric model as shown in Figure 3 is established, and the near-field area and the far-field area are calculated respectively in two steps.

[0088] S33, near-field area calculation

[0089] As shown in Figure 4 , the near-field area is divided into grids, and at least 15 grids should be divided along the diameter direction of the leakage hole, and structured grids are used in the entire near-field area.

[0090] When the near-field area is calculated, the boundary surface between the near-field area and the far-field area adopts a pressure outlet boundary condition.

[0091] The jet flow in the near field is calculated by using simulation software. After the calculation converges, the jet flow velocity, pressure, temperature, density, and turbulence intensity on the boundary surface between the near field and the far field are exported as profile files.

[0092] S34, far field calculation

[0093] As shown in Figure 5 , the grid is divided in the far field, and the grid is locally encrypted around the pipe.

[0094] The profile files exported by the near field calculation are imported into the far field calculation model as boundary conditions.

[0095] Set other required parameters and boundary conditions, and set monitoring points before and after the pipe. The calculation is carried out until the calculation converges.

[0096] S35, result post-processing

[0097] Through simulation software post-processing, the flammable mass and flammable distance under different working conditions are calculated.

[0098] S36, fitting of proportionality coefficient

[0099] The relationship between flammable mass and flammable distance and flow rate is fitted by fitting algorithm. The fitted relationship is as follows:

[0100] y=kx β

[0101] Where k is the to-be-solved C1 and C2, y is the flammable distance and flammable mass, x is the mass flow rate, and β is the index (β=1.5 when calculating the flammable mass; β=0.5 when calculating the flammable distance). Taking the least squares method as an example, the principle of the least squares method is to solve the coefficient k by n sets of observation data points (x i ,y i ), i=1, 2, …, n, so that the sum of the squares of the differences between the predicted value and the measured value is minimized.

[0102] The objective function is:

[0103]

[0104] Take the derivative of the objective function and set it to 0 to get the calculation formula of k:

[0105]

[0106] Bring the simulation results into the calculation formula of k to get Figure 6 and Figure 7The fitting results of the above method. According to the above method, the values of C1 under the conditions of the cooling water pipe diameter D being 8, 15, 20, 25, 30, 35 and 40 mm are 1.038, 0.893, 0.756, 0.693, 0.670, 0.674 and 0.679 respectively, and the value ranges of C2 are 0.078, 0.084, 0.081, 0.071, 0.066, 0.077 and 0.089 respectively.

[0107] S4, optimizing the pipeline arrangement mode by using the empirical relationship

[0108] After obtaining the proportional coefficients under different pipe diameters in S41, the maximum leakage flow of the hydrogen transport pipeline needs to be determined. It is assumed that a catastrophic rupture occurs in the hydrogen transport pipeline, and the maximum leakage flow is about 11.25 g / s. At the same time, according to the design drawings of the hydrogenation station, the shortest distance between the hydrogen transport pipeline and the hydrogen production workshop is about 2.5 m. Therefore, the safety threshold of the hydrogen flammable distance is set to 2.5 m, and the requirement that the hydrogen flammable distance is lower than the threshold when the hydrogen transport pipeline leaks is prioritized, and then the flammable mass is quantitatively evaluated. Among them, in the scenario with lower flammable mass, the overpressure value generated after the explosion is smaller, and such a situation should be prioritized.

[0109] S42, based on the determined maximum leakage flow and the proportional coefficients under different pipe diameters, the flammable distance and the flammable mass are calculated by the empirical formula, and under the conditions of the cooling water pipe diameter being 8, 15, 20, 25, 30, 35 and 40 mm, the corresponding flammable distance is 3.48, 3.00, 2.54, 2.32, 2.25, 2.26 and 2.27 m, and the corresponding flammable mass is 2.94, 3.17, 3.06, 2.68, 2.49, 2.91 and 3.36 g. According to the safety threshold requirement, the pipe diameters whose flammable distance exceeds 2.5 meters (8 mm, 15 mm and 20 mm) should be excluded. Among the remaining diameter specifications, the flammable mass corresponding to the 30 mm pipe is the smallest (2.49 g), so the pipe diameter of the cooling water pipe is preferably 30 mm.

[0110] Embodiment 2:

[0111] The embodiment of the present application also provides a hydrogen transport pipeline optimization arrangement device, which comprises:

[0112] A first processing module is configured to determine the empirical relationship of the hydrogen jet flammable distance and the flammable mass.

[0113] A second processing module is configured to determine the size and position of the adjacent pipeline, set a plurality of leakage flows, and construct a working condition matrix.

[0114] The third processing module is configured to simulate according to the working condition matrix to obtain the combustible mass of hydrogen and the combustible distance, and fit the combustible distance and the combustible mass, the leakage flow according to an empirical relationship to obtain a proportional coefficient.

[0115] The fourth processing module is configured to evaluate according to an empirical relationship according to the pipeline layout requirement, and optimize the pipeline arrangement mode.

[0116] Embodiment 3:

[0117] The embodiment of the present application also provides a hydrogen conveying pipeline optimal arrangement system, which comprises a memory and a processor, the memory is stored with a computer program run by the processor, and the computer program executes the hydrogen conveying pipeline optimal arrangement method when run by the processor.

[0118] Embodiment 4:

[0119] The embodiment of the present application also provides a storage medium, which is stored with a computer program, and the computer program executes the hydrogen conveying pipeline optimal arrangement method when run.

[0120] The above-described embodiments are only descriptions of the preferred modes of the present application, and do not limit the scope of the present application, and various modifications and improvements of the technical solutions of the present application made by those skilled in the art without departing from the design spirit of the present application shall fall within the protection scope of the present application defined by the claims.

Claims

1. A method for optimizing the layout of hydrogen pipelines, characterized in that: include: Step S1, determining an empirical relationship between the flammable distance and flammable mass of the hydrogen jet; Step S2: Determine the size and location of adjacent pipelines, set multiple leakage flow rates, and construct a working condition matrix; Step S3: Perform simulation based on the operating condition matrix to obtain the combustible mass and combustible distance of hydrogen, and fit the combustible distance, combustible mass, and leakage flow rate according to an empirical relationship to obtain a proportional coefficient; Step S4: Based on pipeline layout requirements, evaluate through empirical relationships and optimize the pipeline arrangement.

2. The method for optimizing the layout of hydrogen pipelines according to claim 1, wherein: In the empirical relationship described in step S1, a general relationship between the combustible distance and the combustible mass is derived based on the theory of free jet, wherein the combustible distance and the leakage flow rate are in a power function relationship, and the combustible mass and the leakage flow rate are in a power function relationship.

3. The method for optimizing the layout of hydrogen pipelines according to claim 1, wherein: Step S2 includes: S21. Obtain the size and location of adjacent pipelines within the scene based on the scene's design drawings, process pipelines, and instrument flow charts; S22. Taking the adjacent pipeline diameter as the optimization object, multiple leakage flow rates are selected and formed into a working condition matrix with the adjacent pipeline diameter.

4. The method for optimizing the layout of hydrogen pipelines according to claim 1, wherein: Step S3 includes: S31. Use simulation software to simulate the working condition matrix in different areas and steps; S32. Process the simulation results using post-processing software to obtain the combustible mass and combustible distance; S33. Fit the combustible distance, combustible mass, and leakage flow rate according to the empirical relationship to obtain a proportional coefficient.

5. The method for optimizing the layout of hydrogen pipelines according to claim 1, wherein: Step S4 includes: S41. Determine the worst-case leakage scenario based on the size and design operating conditions of the hydrogen pipeline; S42. Based on pipeline layout requirements, use empirical relationships to evaluate and optimize the pipeline layout.

6. A hydrogen pipeline optimization layout device, characterized in that: include: The first processing module is used to determine the empirical relationship between the flammable distance and flammable mass of the hydrogen jet; The second processing module is used to determine the size and location of adjacent pipelines, set multiple leakage flow rates, and construct an operating condition matrix; The third processing module is used to perform simulation based on the working condition matrix to obtain the combustible mass and combustible distance of hydrogen, and to fit the combustible distance, combustible mass, and leakage flow rate according to the empirical relationship to obtain the proportional coefficient; The fourth processing module is used to evaluate and optimize the pipeline layout according to the pipeline layout requirements through empirical relationships.

7. A hydrogen pipeline optimization layout system, characterized in that: include: A memory and a processor, wherein the memory stores a computer program executed by the processor, and when the computer program is executed by the processor, the method for optimizing the layout of hydrogen transmission pipelines according to any one of claims 1 to 3 is executed.

8. A storage medium, characterized in that: The storage medium stores a computer program, which, when running, executes the method for optimizing the layout of hydrogen transmission pipelines according to any one of claims 1 to 3.

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