Methods, devices, systems, and storage media for optimizing the layout of hydrogen pipelines

Abstract

This invention discloses a method, apparatus, system, and storage medium for optimizing the layout of hydrogen transportation pipelines, comprising: Step S1, determining the empirical relationship between the flammable distance and flammable mass of the hydrogen jet; Step S2, determining the size and location of adjacent pipelines, setting multiple leakage flow rates, and constructing an operating condition matrix; Step S3, performing simulation based on the operating condition matrix to obtain the flammable mass and flammable distance of hydrogen, and fitting the flammable distance, flammable mass, and leakage flow rate according to the empirical relationship to obtain a proportionality coefficient; Step S4, optimizing the pipeline layout based on pipeline layout requirements and through evaluation using the empirical relationship. The technical solution of this invention solves the safety hazards caused by unreasonable hydrogen transportation pipeline layouts in existing hydrogen energy sites.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen safety technology, and in particular relates to a method, device, system, and storage medium for optimizing the layout of hydrogen transportation pipelines. Background Technology

[0002] Hydrogen is a clean, efficient, widely available, and flexible fuel, widely considered one of the most valuable alternative energy sources of this century. With the rapid development of the hydrogen energy industry, the number of hydrogen energy facilities, such as hydrogen refueling stations, hydrogen production plants, and skid-mounted hydrogen energy units, is constantly increasing. As a flammable and explosive gas, the safety of hydrogen has always been a focus of public and industry attention. Hydrogen leaks can easily lead to accidents, especially in hydrogen energy sites such as refueling stations and hydrogen production plants, where the layout of hydrogen pipelines significantly affects the diffusion characteristics of leaked hydrogen. However, current safety regulations for hydrogen-related sites are incomplete, and there is a lack of scientific optimization methods for the layout of hydrogen pipelines. Therefore, there is an urgent need for a safety analysis-based method for optimizing the layout of hydrogen pipelines to improve the safety of hydrogen energy sites. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide a method, device, system, and storage medium for optimizing the layout of hydrogen transportation pipelines, thereby addressing the safety hazards caused by unreasonable layout of hydrogen transportation pipelines in existing hydrogen energy sites. Based on the calculation of the flammable distance and flammable mass after hydrogen leakage under different pipeline layout conditions, this invention can be customized and optimized according to the specific scenario of the hydrogen energy site, thereby reducing the flammability risk after hydrogen leakage and improving the overall safety of the hydrogen energy site.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A method for optimizing the layout of hydrogen transportation pipelines includes:

[0006] Step S1: Determine the empirical relationship between the flammable distance and flammable mass of the hydrogen jet;

[0007] Step S2: Determine the size and location of adjacent pipes, set multiple leakage flow rates, and construct a working condition matrix;

[0008] Step S3: Perform simulation based on the working condition matrix to obtain the combustible mass and combustible distance of hydrogen. Fit the combustible distance, combustible mass, and leakage flow rate according to the empirical relationship to obtain the proportionality coefficient.

[0009] Step S4: Based on the pipeline layout requirements, evaluate the pipeline layout using empirical formulas and optimize the pipeline arrangement.

[0010] Preferably, step S1 includes:

[0011] S11. Based on the free jet theory, make reasonable assumptions about the model;

[0012] S12. Based on the assumptions, derive the relationship between the flammability distance of hydrogen and the flow rate;

[0013] S13. Based on the assumptions, derive the relationship between the combustible mass of hydrogen and its flow rate.

[0014] Preferably, step S2 includes:

[0015] S21. Based on the design drawings, process piping, and instrumentation diagrams of the scene, obtain the dimensions and locations of adjacent pipes within the scene;

[0016] S22. Using the diameter of the adjacent pipe as the optimization object, select multiple leakage flow rates and form a working condition matrix with the diameter of the adjacent pipe.

[0017] Preferably, step S3 includes:

[0018] S31. Use simulation software to perform zoned and step-by-step simulation of the operating condition matrix;

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

[0020] S33. Fit the combustible distance, combustible mass, and leakage flow rate according to the empirical formula to obtain the proportionality coefficient.

[0021] Preferably, step S4 includes:

[0022] S41. Determine the worst-case leakage scenario based on the size and design conditions of the hydrogen pipeline;

[0023] S42. Based on pipeline layout requirements, use empirical formulas to evaluate and optimize the pipeline layout.

[0024] The present invention also provides a hydrogen pipeline optimization layout device, comprising:

[0025] The first processing module is used to determine the empirical relationship between the flammability distance and flammability mass of the hydrogen jet;

[0026] The second processing module is used to determine the size and location of adjacent pipes, set multiple leakage flow rates, and construct a working condition matrix.

[0027] The third processing module is used to perform simulation based on the operating condition matrix to obtain the combustible mass and combustible distance of hydrogen. Based on empirical formulas, it fits the combustible distance, combustible mass, and leakage flow rate to obtain the proportionality coefficient.

[0028] The fourth processing module is used to optimize the pipeline layout by evaluating based on empirical relationships according to pipeline layout requirements.

[0029] The present invention also provides a hydrogen pipeline optimization layout system, comprising: a memory and a processor, wherein the memory stores a computer program executed by the processor, and the computer program executes a hydrogen pipeline optimization layout method when executed by the processor.

[0030] The present invention also provides a storage medium storing a computer program, which executes a hydrogen pipeline optimization layout method when running.

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

[0032] 1. This invention can be customized and optimized according to the pipeline type involved in hydrogen energy sites, thereby reducing the flammability risk after hydrogen leakage and improving the overall safety of hydrogen energy sites.

[0033] 2. This invention establishes an empirical relationship between the combustible mass and combustible distance of a hydrogen jet and the leakage flow rate, which can quickly and accurately calculate the combustible mass and combustible distance after leakage based on the estimated leakage flow rate;

[0034] 3. Based on the empirical relationship between the combustible mass and combustible distance of hydrogen jet and the leakage flow rate, this invention proposes to use different coefficients to characterize the influence of adjacent pipes on combustible mass and combustible distance, and can quickly calculate the combustible mass and combustible distance when the jet impacts the pipe based on the estimated leakage flow rate.

[0035] 4. The present invention adopts a partitioned and step-by-step simulation method, which greatly improves the calculation efficiency while ensuring calculation accuracy. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0037] Figure 1 This is a flowchart of the hydrogen pipeline optimization layout method according to an embodiment of the present invention;

[0038] Figure 2 This is the operating condition matrix composed of different leakage scales proposed in this invention;

[0039] Figure 3 This is a diagram showing the flow field region division of the computational model of this invention;

[0040] Figure 4 This is a computational mesh diagram of the near-field region of this invention;

[0041] Figure 5 This is a computational mesh diagram of the far-field region of this invention;

[0042] Figure 6 This is the fitting result of the combustible mass and leakage flow rate under different pipe diameters according to the present invention;

[0043] Figure 7 This is the fitting result of the combustible distance and leakage flow rate under different pipe diameters according to the present invention; Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0046] Example 1:

[0047] A hydrogen refueling station needs to install a cooling water pipe around its existing hydrogen pipeline. The cooling water pipe will run parallel to the hydrogen pipeline, 100mm away. The existing cooling water pipes have diameters of 8, 15, 20, 25, 30, 35, and 40mm. The hydrogen pipeline has a diameter of 19.05mm, a wall thickness of approximately 4mm, a design pressure of 10MPa, and a gas velocity of 8m / s. Since a hydrogen production workshop is located in the pipeline's location, it is necessary to ensure that any hydrogen leaks will have minimal impact on the hydrogen production workshop. Figure 1 As shown, this embodiment of the invention provides a method for optimizing the layout of hydrogen transportation pipelines. By substituting parameters such as leakage flow rate of relevant components in hydrogen-related sites and the diameter of adjacent pipelines into a constructed model, the combustible mass and combustible distance of hydrogen are ultimately calculated, thus providing a scientific basis for optimizing pipeline layout in hydrogen energy sites. Specifically, it includes the following steps:

[0048] S1. Empirical formula for determining the flammable distance and flammable mass of hydrogen jet.

[0049] S11, Model Assumptions

[0050] (1) Due to the high hydrogen pressure in the hydrogen pipeline, hydrogen leakage will form a high-pressure underexpansion jet. Therefore, the initial momentum of the jet is very high, the buoyancy has a weak effect on the jet, and the jet is a momentum-dominated jet.

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

[0052] (3) During the process of gas leaking from the inside of the pipe to the outside, the heat exchange between the gas flow and the pipe 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 combustible distance

[0054] If the concentration decay of a hydrogen jet along the jet centerline in the momentum-dominant region follows a hyperbolic decay law, then for a given concentration value Y along the jet axis... s Corresponding axial position z s It can be calculated using the following formula:

[0055]

[0056] Among them, C d d is the attenuation coefficient. e ρ is the diameter of the leakage hole. e and ρ ∞ These represent the density of the jet gas at the outlet of the leak hole 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 The velocity at the leak outlet, i.e., the local speed of sound, can be calculated using the relationships between ideal gas or real gas property parameters. Further application of the isentropic expansion relationship yields u. e The relationship between the temperature T0 of the gas inside the pipe and the temperature T0 is as follows:

[0060]

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

[0062]

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

[0064]

[0065] Where C1 is the first proportionality coefficient, and Y s ρ ∞ And related to T0, its expression is:

[0066]

[0067] Where R represents the universal gas constant.

[0068] When Y s Take the lower limit of flammability Y LFL Then, the relationship between the combustible 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 limit of flammability Y LFL The value of C1 at that time.

[0071] S13, Calculation of combustible mass

[0072] The radial concentration of the hydrogen jet follows a Gaussian distribution. It is assumed that the density of the mixed gas within the computational region remains constant, and is equal to the density of the surrounding air, ρ. ∞ Then the combustible mass of hydrogen is m f The mass of hydrogen gas between the lower flammability limit (LFL) and the upper flammability limit (UFL) can be calculated using the following formula:

[0073]

[0074] Where z represents the axial distance from the nozzle outlet, and r represents the radial distance from the jet axis. LFL and r UFL These represent the radial positions corresponding to the lower and upper flammability limits, respectively, z. LFL and z UFL These represent the axial positions corresponding to the lower and upper flammability limits, respectively, Y. cl r represents the gas mass fraction along the centerline of the jet. 0.5 The distance from the jet axis to the position where the hydrogen mass fraction is half that at the jet centerline on the plane, at a certain distance from the nozzle exit cross-section, can be expressed by r. 0.5 =C c z is calculated to yield C c C r These are the third and fourth proportionality coefficients, respectively, C c C r All results were obtained through fitting.

[0075] By consolidation, we can obtain:

[0076]

[0077] Where C2 is the second proportionality coefficient, and it is related to ρ.∞ Y s Related to T0, its expression is:

[0078]

[0079] Among them, Y UFL C represents the upper limit of flammability of combustible gases. 1,UFL Represents Y s Take the upper limit of flammability Y UFL The value of C1 at that time.

[0080] S2. Construct a working condition matrix based on the size and location of adjacent pipes.

[0081] S21. Based on the design drawings, process piping and instrumentation diagram of the scenario, the available cooling water pipe diameters within the scenario are 8, 15, 20, 25, 30, 35 and 40 mm, and the distance between the cooling water pipe and the hydrogen transmission pipe is 100 mm.

[0082] S22. Using the cooling water pipe diameter as the optimization object, select multiple leakage flow rates and construct a working condition matrix with the cooling water pipe diameter, such as... Figure 2 As shown.

[0083] S3. The proportionality coefficient of the empirical relationship obtained by fitting the combustible distance and combustible mass with the leakage flow rate.

[0084] S31, Geometric Model Construction

[0085] Create a cooling water pipe outside the leak hole based on the operating condition matrix.

[0086] S32. Computational Domain Partitioning

[0087] Because a shock wave exists within a short distance outside the leak hole, causing drastic changes in flow parameters, a very fine mesh is required. Outside the shock wave region, however, the flow parameter changes are relatively gradual, allowing for a coarser mesh to reduce the overall mesh count. Therefore, the computational domain is divided into a near-field region and a far-field region, with the cooling water pipes placed in the far-field region. The following steps are taken: Figure 3 The geometric model shown is used to perform calculations in two steps for the near-field region and the far-field region, respectively.

[0088] S33, Near-field calculation

[0089] like Figure 4 As shown, the near-field region should be meshed, with at least 15 meshes along the diameter of the leakage hole, and a structured mesh should be used for the entire near-field region.

[0090] In the near-field calculation, the boundary surface between the near-field and far-field regions adopts the pressure outlet boundary condition.

[0091] The jet in the near-field region is calculated using simulation software. After the calculation converges, parameters such as jet velocity, pressure, temperature, density, and turbulence intensity at the boundary between the near-field and far-field regions are exported as profile files.

[0092] S34, Far-field region calculation

[0093] like Figure 5 As shown, the far-field region is meshed, and the mesh is locally refined around the pipe.

[0094] The profile file exported from the near-field region calculation is imported as boundary conditions into the far-field region calculation model.

[0095] Set other necessary parameters and boundary conditions, set monitoring points before and after the pipeline, and perform calculations until the calculations converge.

[0096] S35. Post-processing of results

[0097] The combustible mass and combustible distance under different working conditions are calculated through post-processing of simulation software.

[0098] S36, Proportional coefficient fitting

[0099] The relationship between combustible mass, combustible distance, and flow rate was fitted using a fitting algorithm. The relationship to be fitted is in the form of:

[0100] y = kx β

[0101] Where k represents C1 and C2 to be determined, y represents the flammable distance and flammable mass, x represents the mass flow rate, and β is the exponent (β = 1.5 when calculating flammable mass; β = 0.5 when calculating flammable distance). Taking the least squares method as an example, the principle of the least squares method is to use n sets of observation data points (x... i ,y i Given i = 1, 2, ..., n, solve for the coefficient k such that the sum of the squares of the differences between the predicted and measured values ​​is minimized.

[0102] The objective function is:

[0103]

[0104] By differentiating the objective function and setting it to 0, we can obtain the formula for calculating k:

[0105]

[0106] Substituting the simulation results into the formula for calculating k, we can obtain... Figure 6 and Figure 7The fitting results are as follows. Based on the above method, the fitting results show that for cooling water pipe diameters D of 8, 15, 20, 25, 30, 35, and 40 mm, the values ​​of C1 are 1.038, 0.893, 0.756, 0.693, 0.670, 0.674, and 0.679, respectively, and the values ​​of C2 are 0.078, 0.084, 0.081, 0.071, 0.066, 0.077, and 0.089, respectively.

[0107] S4. Optimize pipeline layout using empirical relationships.

[0108] After obtaining the proportional coefficients for different pipe diameters in S41, it is necessary to determine the maximum leakage flow rate of the hydrogen pipeline. Assuming a catastrophic rupture in the hydrogen pipeline, the maximum leakage flow rate is approximately 11.25 g / s. Meanwhile, according to the hydrogen refueling station design drawings, the shortest distance between the hydrogen pipeline and the hydrogen production workshop is approximately 2.5 m. Therefore, the safety threshold for the flammable distance of hydrogen is set at 2.5 m. Priority is given to ensuring that the flammable distance of hydrogen remains below this threshold during a pipeline leak, thereby quantifying the flammability. In scenarios with lower flammability, the overpressure value generated after the explosion is smaller, and such situations should be given priority.

[0109] Based on the determined maximum leakage flow rate and proportional coefficients for different pipe diameters, S42 calculates the flammable distance and flammable mass using empirical formulas. For cooling water pipe diameters of 8, 15, 20, 25, 30, 35, and 40 mm, the corresponding flammable distances are 3.48, 3.00, 2.54, 2.32, 2.25, 2.26, and 2.27 m, respectively, and the corresponding flammable masses are 2.94, 3.17, 3.06, 2.68, 2.49, 2.91, and 3.36 g, respectively. According to safety threshold requirements, pipe diameters (8 mm, 15 mm, and 20 mm) with flammable distances exceeding 2.5 meters should be excluded. Among the remaining diameter specifications, the 30 mm pipe has the lowest flammable mass (2.49 g), therefore, the preferred pipe diameter for the cooling water is 30 mm.

[0110] Example 2:

[0111] This invention also provides a hydrogen pipeline optimization layout device, comprising:

[0112] The first processing module is used to determine the empirical relationship between the flammability distance and flammability mass of the hydrogen jet;

[0113] The second processing module is used to determine the size and location of adjacent pipes, set multiple leakage flow rates, and construct a working condition matrix.

[0114] The third processing module is used to perform simulation based on the operating condition matrix to obtain the combustible mass and combustible distance of hydrogen. Based on empirical formulas, it fits the combustible distance, combustible mass, and leakage flow rate to obtain the proportionality coefficient.

[0115] The fourth processing module is used to optimize the pipeline layout by evaluating based on empirical relationships according to pipeline layout requirements.

[0116] Example 3:

[0117] This invention also provides a hydrogen pipeline optimization layout system, comprising: a memory and a processor, wherein the memory stores a computer program executed by the processor, and the computer program executes a hydrogen pipeline optimization layout method when run by the processor.

[0118] Example 4:

[0119] This invention also provides a storage medium storing a computer program that executes a hydrogen pipeline optimization layout method during runtime.

[0120] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for optimizing the layout of hydrogen transportation pipelines, characterized in that, include: Step S1: Determine the empirical relationship between the combustible distance and flow rate of the hydrogen jet, and the empirical relationship between the combustible mass and flow rate. Step S2: Determine the size and location of adjacent pipes, set multiple leakage flow rates, and construct a working condition matrix; Step S3: Perform simulation based on the working condition matrix to obtain the combustible mass and combustible distance of hydrogen. Fit the combustible distance with leakage flow rate and the combustible mass with leakage flow rate to obtain the proportional coefficients for different pipe diameters. The proportional coefficients include the proportional coefficient C1 in the empirical formula for combustible distance and the proportional coefficient C2 in the empirical formula for combustible mass. Step S4: Based on the pipeline layout requirements, evaluate the pipeline layout using empirical formulas and optimize the pipeline arrangement.

2. The optimized layout method for hydrogen transportation pipelines as described in claim 1, characterized in that, In the empirical relationship described in step S1, based on the theory of free jet, a general relationship between flammable distance and flammable mass is derived, wherein the flammable distance and leakage flow rate are power functions, and the flammable mass and leakage flow rate are power functions.

3. The hydrogen pipeline optimization layout method as described in claim 1, characterized in that, Step S2 includes: S21. Based on the design drawings, process piping, and instrumentation diagrams of the scene, obtain the dimensions and locations of adjacent pipes within the scene; S22. Using the diameter of adjacent pipes as the optimization object, select multiple leakage flow rates and form a working condition matrix with the diameter of adjacent pipes.

4. The optimized layout method for hydrogen transportation pipelines as described in claim 1, characterized in that, Step S3 includes: S31. Use simulation software to perform zoned and step-by-step simulation of the operating condition matrix; S32. Use post-processing software to process the simulation results to obtain the combustible mass and combustible distance; S33. Fit the combustible distance, combustible mass, and leakage flow rate according to the empirical formula to obtain the proportionality coefficient.

5. The optimized layout method for hydrogen transportation pipelines as described in claim 1, characterized in that, Step S4 includes: S41. Determine the worst-case leakage scenario based on the size and design conditions of the hydrogen pipeline; S42. Based on pipeline layout requirements, use empirical formulas 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 flow rate of the hydrogen jet and the empirical relationship between the flammable mass and flow rate. The second processing module is used to determine the size and location of adjacent pipes, set multiple leakage flow rates, and construct a working 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. It then fits the combustible distance with the leakage flow rate and the combustible mass with the leakage flow rate to obtain the proportional coefficients for different pipe diameters. These proportional coefficients include the proportional coefficient C1 in the empirical formula for combustible distance and the proportional coefficient C2 in the empirical formula for combustible mass. The fourth processing module is used to optimize the pipeline layout by evaluating based on empirical relationships according to pipeline layout requirements.

7. An optimized layout system for hydrogen transportation pipelines, characterized in that, include: A memory and a processor, wherein the memory stores a computer program executed by the processor, the computer program performing the hydrogen pipeline optimization layout method as described in any one of claims 1-3 when executed by the processor.

8. A storage medium, characterized in that, The storage medium stores a computer program that, when executed, performs the hydrogen pipeline optimization layout method as described in any one of claims 1-3.

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