A method for predicting concentration of low-pressure hydrogen leakage jet field

Abstract

The application provides a kind of middle-low pressure hydrogen leakage jet field concentration prediction method, belong to the technical field of hydrogen energy safety application, including obtaining middle-low pressure hydrogen jet field experimental test concentration data;According to the middle-low pressure hydrogen jet field experimental test concentration data obtained, a jet field concentration prediction model is constructed;Based on the constructed jet field concentration prediction model, middle-low pressure hydrogen leakage jet field concentration prediction is carried out.The middle-low pressure hydrogen leakage jet field concentration prediction method provided by the application not only solves the complexity of experimental test, the problem of large interference, etc., but also avoids the engineering error problem of numerical simulation, effectively solves the difficulty of middle-low pressure hydrogen leakage jet field concentration acquisition.

Description

Technical Field

[0001] This invention relates to the technical field of hydrogen energy safety applications, and in particular to a method for predicting the concentration distribution characteristics of a jet field after a medium- or low-pressure hydrogen leak. Background Technology

[0002] With the increasing adoption of new energy sources such as hydrogen, numerous industrial and civilian hydrogen-related sites will emerge in the future. In the event of a hydrogen leak at such sites, the ejected hydrogen gas can disperse throughout the work environment, posing a significant explosion hazard. To prevent such catastrophic accidents, researching and determining the jet field distribution characteristics of medium- and low-pressure hydrogen after a leak is of significant safety guidance value.

[0003] The study of jet field distribution characteristics after medium and low pressure hydrogen leakage is currently mainly carried out through experimental testing, numerical simulation and other methods.

[0004] One type of testing involves experiments. However, this method currently employs two approaches: either pre-planning measurement points within the jet region or conducting point-by-point testing using a handheld device. For the pre-planning method, the excessive number of sampling points significantly disturbs the jet field, negatively impacting test accuracy. For handheld testing, the lack of precise positioning technology due to manual operation often results in significant discrepancies between the measured data and the expected locations, leading to considerable randomness. Furthermore, experimental testing using pure spectroscopic instruments is costly and requires stringent environmental conditions.

[0005] Another type of research involves conducting studies through fluid numerical simulation. Due to numerous influencing factors, existing jet field pressure and expansion models differ from reality. Therefore, relying solely on numerical simulation methods to study gas jet fields is not reliable enough. Summary of the Invention

[0006] To address the above problems, this invention provides a method for predicting the concentration of hydrogen leakage jet field in medium and low pressure, which improves the stability and reliability of jet field concentration acquisition. The prediction results can provide decision-makers with a scientific basis to guide them in formulating more reasonable and effective emergency response plans and preventive measures, thereby reducing accident risks and losses.

[0007] This invention provides a method for predicting the concentration of hydrogen leakage jet fields at medium and low pressures, comprising: Obtain experimental concentration data for hydrogen jet fields at medium and low pressure; Based on the obtained experimental concentration data of the medium and low pressure hydrogen jet field, a jet field concentration prediction model is constructed. Based on the constructed jet field concentration prediction model, the concentration of the medium- and low-pressure hydrogen leakage jet field is predicted.

[0008] As a further improvement of the present invention, the acquisition of experimental test concentration data of medium and low pressure hydrogen jet field includes acquiring experimental test concentration data of medium and low pressure hydrogen jet field under different leakage orifice diameters, including the minimum leakage orifice diameter and the maximum leakage orifice diameter.

[0009] As a further improvement of the present invention, the step of constructing a jet field concentration prediction model based on the obtained experimental test concentration data of the medium and low pressure hydrogen jet field includes determining the empirical formulas for jet field concentration under the minimum leakage orifice diameter and the maximum leakage orifice diameter, and constructing the jet field concentration prediction model based on the determined empirical formulas for jet field concentration under the minimum leakage orifice diameter and the maximum leakage orifice diameter.

[0010] As a further improvement of the present invention, the empirical formula for jet field concentration includes at least one of the empirical formula for axial concentration, empirical formula for axial midline concentration, and empirical formula for edgeline concentration. The jet field concentration prediction model is constructed based on at least one of the empirical formulas for axial concentration, axial midline concentration, and edgeline concentration.

[0011] As a further improvement of the present invention, the empirical formula for determining the jet field concentration under the minimum leakage orifice diameter and the maximum leakage orifice diameter includes taking the average concentration under all pressure conditions at the same distance from the leakage orifice, and using the calculated average concentration to fit the empirical formula trend line.

[0012] As a further improvement of the present invention, the step of constructing the jet field concentration prediction model based on the empirical formula for the jet field concentration under the determined minimum and maximum leakage orifice diameters includes determining the location concentration multiple relationship formula and constructing the jet field concentration prediction model based on the empirical formula for the jet field concentration under the minimum and / or maximum leakage orifice diameters.

[0013] The location concentration ratio formula includes at least one of the following: B 轴线 =0.0382Ln(x)+1.318 B 轴侧中线 = 0.0176Ln(x)+1.1782 B 边线 =0.3959Ln(x)+2.38; Where x is the jet distance; B 轴线 The formula for the axial concentration ratio at all locations under the maximum and minimum leakage orifice diameters; B 轴侧中线 The formula for the concentration ratio of the axial centerline at all locations under the maximum and minimum leakage orifice diameters; B 边线 This is the formula for the concentration ratio of all locations along the edge under the maximum and minimum leakage orifice diameters.

[0014] As a further improvement of the present invention, the jet field concentration prediction model includes at least one of the axis concentration prediction model, the axisymmetric centerline concentration prediction model, and the edgeline concentration prediction model. Based on the determined position concentration multiple relationship, the corresponding jet field concentration prediction model is constructed according to at least one of the axis concentration empirical formula, the axisymmetric centerline concentration empirical formula, and the edgeline concentration empirical formula.

[0015] As a further improvement of the present invention, the jet field concentration prediction model includes at least one of the following models: C 轴线Kmm =(-0.13267Ln(x)+0.4083)×(1+(0.0382Ln(x)+1.318)-1)×((Kj) / n)); C 轴侧中线Kmm =(-0.115Ln(x)+0.3583)×(1+((0.0176Ln(x)+1.1782)-1)×((Kj) / n)); C 边线Kmm = (-0.067Ln(x)+0.1152)×(1+((0.3959Ln(x)+2.38)-1)×((Kj) / n)); Where x is the jet distance, m; n is the number of equal divisions between the minimum and maximum leakage orifice diameters; j is the minimum leakage orifice diameter, mm; K is the leakage orifice diameter, greater than or equal to j, mm; C 轴线Kmm ---K leakage orifice shape, axial jet concentration, C 轴侧中线Kmm --- K leakage orifice diameter, centerline jet concentration on the shaft side, C 边线Kmm ---K leakage orifice lower edge jet concentration,%.

[0016] As a further improvement of the present invention, the minimum leakage orifice diameter is 5 mm and the maximum leakage orifice diameter is 20 mm.

[0017] As a further improvement of the present invention, the medium and low pressure refers to a pressure value of 2 MPa or below.

[0018] This invention provides a method for predicting the concentration of hydrogen leakage jet fields in medium- and low-pressure environments. First, experimental concentration data of the hydrogen jet field in medium- and low-pressure environments is obtained. Then, based on this data, a jet field concentration prediction model is constructed. Finally, based on this model, the concentration of hydrogen leakage jet fields in medium- and low-pressure environments is predicted. This method provides rapid and robust computational and data support for the distribution characteristics of hydrogen flow fields after a medium- and low-pressure hydrogen leak in hydrogen-related locations. The method is convenient, simple, fast, and relatively accurate, and the prediction results have high reference value, effectively meeting the needs of engineering safety measures and decision-making. Attached Figure Description

[0019] Figure 1 This is a schematic flowchart of the method for predicting the concentration of hydrogen leakage jet field in medium and low pressure according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the concentration variation of the jet field axis under different leakage orifice diameters according to an embodiment of the present invention. The vertical axis represents the concentration, and the horizontal axis represents the distance.

[0021] Figure 3 This is a schematic diagram of the concentration variation along the centerline of the jet field under different leakage orifice diameters according to an embodiment of the present invention. The vertical axis represents the concentration, and the horizontal axis represents the distance.

[0022] Figure 4 This is a schematic diagram of the concentration variation along the edge of the jet field under different leakage orifice diameters according to an embodiment of the present invention. The vertical axis represents the concentration, and the horizontal axis represents the distance. Detailed Implementation

[0023] The following describes specific embodiments and appendices. Figure 1-4 The invention is described in detail so that those skilled in the art can more fully understand its purpose, features and effects.

[0024] Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of any discrepancy between the definitions of terms in this invention and their commonly understood meaning by one of ordinary skill in the art to which this invention pertains, the definitions set forth herein shall prevail.

[0025] For hydrogen gas stored in low- and medium-pressure containers, studying the jet field distribution characteristics after leakage is of great significance for accident prevention, especially the prevention of explosions. Currently, the methods for obtaining the spatial distribution characteristics of the leaked jet field of hydrogen and other gases mainly fall into two categories: experimental and numerical simulation. However, both methods still have some limitations.

[0026] This invention provides a method for predicting the concentration of hydrogen leakage jet fields under medium and low pressure, thereby improving the stability and reliability of the prediction.

[0027] Example 1 As a specific embodiment of the present invention, this embodiment provides a method for predicting the concentration of hydrogen leakage jet field in medium and low pressure systems, referring to... Figure 1 The specific steps are as follows: S100. Obtain experimental concentration data for medium and low pressure hydrogen jet field. S200. Based on the obtained experimental concentration data of the medium- and low-pressure hydrogen jet field, construct a jet field concentration prediction model. S300. Based on the constructed jet field concentration prediction model, predict the concentration of the medium- and low-pressure hydrogen leakage jet field.

[0028] The term "medium and low pressure" refers to a pressure value of 2 MPa or below.

[0029] This embodiment obtains real and high-precision concentration data of the jet field through actual medium and low pressure hydrogen jet field experiments. These data reflect the actual diffusion of hydrogen under different pressures and flow rates, providing a reliable foundation for the subsequent construction of the jet field concentration prediction model and improving the accuracy of the model construction. Compared with traditional numerical simulation methods, model construction based on experimental data can significantly reduce the amount of computation, improve computational efficiency, and achieve fast and accurate concentration prediction.

[0030] The method for predicting the concentration of hydrogen leakage jet field in medium and low pressure provided by this invention is based on a prediction model for the concentration distribution characteristics of hydrogen leakage jet field in medium and low pressure, established by a large amount of experimental test data. It not only solves the problems of complexity, large interference, and high equipment requirements of experimental testing, but also avoids the engineering error problems of numerical simulation, effectively solving the difficulty of obtaining the concentration of hydrogen jet field in medium and low pressure. It can be easily and quickly calculated and predicted on the engineering site, providing corresponding theoretical and technical support for efficiently and scientifically understanding the jet field distribution characteristics after medium and low pressure hydrogen leakage in relevant work sites. It is of great significance for the research and rapid prediction of the concentration distribution of hydrogen jet field in medium and low pressure.

[0031] Example 2 As a specific embodiment of the present invention, this embodiment provides a method for predicting the concentration of hydrogen leakage jet field in medium and low pressure systems. Based on Embodiment 1, it further includes: In S100, obtaining experimental test concentration data of medium and low pressure hydrogen jet field includes obtaining experimental test concentration data of medium and low pressure hydrogen jet field under different leakage orifice diameters.

[0032] Specifically, in this embodiment, taking leakage orifice diameters of 5mm, 10mm, and 20mm as examples, experimental tests were conducted on the jet field distribution characteristics of medium- and low-pressure hydrogen leakage under different leakage orifice diameters to obtain jet field experimental test concentration data under different orifice diameters. 5mm was used as the minimum leakage orifice diameter, and 20mm as the maximum leakage orifice diameter. By simulating the jet field concentration distribution characteristics under various leakage orifice diameters through actual medium- and low-pressure hydrogen jet field experiments, more comprehensive and realistic concentration data can be obtained. In other optional embodiments, jet field experimental test concentration data under other leakage orifice diameters may also be included.

[0033] The experimental concentration data curves of the jet field under leakage orifice diameters of 5mm, 10mm and 20mm showed similar trends, all exhibiting the following characteristics: at the same jet distance, the experimental concentration data value corresponding to the 5mm leakage orifice diameter was the lowest, the experimental concentration data value corresponding to the 20mm leakage orifice diameter was the highest, and the experimental concentration data value corresponding to the 10mm leakage orifice diameter was between that of the 5mm and 20mm leakage orifice diameters.

[0034] This embodiment analyzes the trends of concentration data curves from the jet field experiments under different leakage orifice diameters to obtain the distribution characteristics of the concentration data. Detailed experimental testing for different leakage orifice diameters can yield more comprehensive and accurate concentration data. This data can more accurately reflect the diffusion characteristics of hydrogen under different leakage conditions, thereby constructing a more accurate prediction model.

[0035] In S200, based on the analysis of experimental concentration data obtained from S100 at leakage orifice diameters of 5mm, 10mm, and 20mm, further findings include: S201. Empirical formulas for determining jet field concentration under minimum and maximum leakage orifice diameters. In this embodiment, 5mm is taken as the minimum leakage orifice diameter and 20mm as the maximum leakage orifice diameter in S100. Therefore, in S201, empirical formulas for jet field concentration under leakage orifice diameters of 5mm and 20mm are determined. The empirical formulas for jet field concentration include empirical formulas for axial concentration, axial centerline concentration, and edgeline concentration.

[0036] Since the trends of the jet field concentration data curves under leakage orifice diameters of 5mm, 10mm, and 20mm are similar, and the experimental concentration data value corresponding to the 10mm leakage orifice diameter is located between the experimental concentration data values ​​corresponding to the 5mm and 20mm leakage orifice diameters, it can be inferred that the trends of the jet field concentration data curves under other leakage orifice diameters (5-20mm) are similar, also located between the experimental concentration data values ​​corresponding to the 5mm and 20mm leakage orifice diameters. Therefore, empirical formulas for jet field concentration under the minimum and maximum leakage orifice diameters are determined, and then a jet field concentration prediction model under leakage orifice diameters of 5-20mm is constructed based on the empirical formulas for jet field concentration under the minimum and maximum leakage orifice diameters.

[0037] The experimental concentration data of the jet field under different apertures obtained by conducting experimental tests on the distribution characteristics of the hydrogen leakage jet field under different apertures are more consistent with the actual working conditions. The empirical formula for the jet field concentration determined based on the experimental concentration data of the jet field under different apertures can more accurately describe the distribution characteristics of the hydrogen leakage jet field under different apertures and has high reliability.

[0038] Specifically, based on the experimental test concentration data obtained in S100 for leakage orifice diameters of 5mm and 20mm, an empirical formula for the shaft concentration is established.

[0039] For a 5mm leak orifice diameter, the data under various pressure conditions are relatively similar. First, the concentration values ​​are averaged across all pressure conditions at the corresponding locations. For example, for a 5mm leak orifice diameter, the average concentrations at pressures of 0.5MPa, 1MPa, 1.5MPa, and 2MPa at a location 0.1m from the leak opening are averaged, and so on. Then, the calculated average concentrations are used to fit an empirical formula trend line. C 轴线5mm = -0.13267Ln(x)+0.4083, R 2 = 0.9994 (1) Where x---jet distance, m; C 轴线5mm ---Concentration of axial jet at a leakage orifice diameter of 5mm.

[0040] Through the above methods, the empirical formula for the axis concentration under a 5mm leakage orifice diameter was obtained. This embodiment uses regression analysis to determine the empirical formula for the axis concentration. In other feasible embodiments, other methods can also be used to construct the axis jet concentration, with the aim of obtaining an empirical formula for the axis concentration with high stability and reliability.

[0041] For a 20mm leak orifice diameter, the data under various pressure conditions are relatively similar. First, the concentration values ​​are averaged across all pressure conditions at the corresponding locations. For example, for a 20mm leak orifice diameter, the average concentrations at 0.5MPa, 1MPa, 1.5MPa, and 2MPa at a distance of 0.1m from the leak opening are averaged, and so on. Then, the calculated average concentrations are used to fit an empirical formula trend line. C 轴线20mm = -0.153Ln(x)+0.528,R 2 = 0.9993 (2) Where x---jet distance, m; C 轴线20mm ---Concentration of axial jet under a 20mm leakage orifice diameter.

[0042] Through the above methods, the empirical formula for the axial concentration under a 20mm leakage orifice diameter was obtained.

[0043] Specifically, based on the experimental test concentration data obtained in S100 for leakage orifice diameters of 5mm and 20mm, an empirical formula for the axial midline concentration is established.

[0044] For a 5mm leak orifice diameter, the data under various pressure conditions are relatively similar. First, the average concentration values ​​are taken for all pressure conditions at the corresponding locations. For example, for a 5mm leak orifice diameter, the average concentrations at 0.5MPa, 1MPa, 1.5MPa, and 2MPa at a distance of 0.1m from the leak opening are taken, and so on. Then, the calculated average concentration values ​​are used to fit an empirical formula trend line. C 轴侧中线5mm = -0.115Ln(x)+0.358, R 2 = 0.9993 (3) Where x -- jet distance, m; C 轴侧中线5mm ---Jet concentration at the centerline of the shaft side under a 5mm leakage orifice diameter.

[0045] Through the above methods, the empirical formula for the axial centerline concentration under a 5mm leakage orifice diameter was obtained.

[0046] For a 20mm leak orifice diameter, the data under various pressure conditions are relatively similar. First, the concentration values ​​are averaged across all pressure conditions at the corresponding locations. For example, for a 20mm leak orifice diameter, the average concentrations at 0.5MPa, 1MPa, 1.5MPa, and 2MPa at a distance of 0.1m from the leak opening are averaged, and so on. Then, the calculated average concentrations are used to fit an empirical formula trend line. C 轴侧中线20mm =-0.143Ln(x)+0.458, R 2 = 0.9992 (4) Where x---jet distance, m; C 轴侧中线20mm ---Jet concentration at the centerline of the shaft side under a 20mm leakage orifice diameter.

[0047] Through the above methods, the empirical formula for the axial centerline concentration under a 20mm leakage orifice diameter was obtained.

[0048] Specifically, based on the experimental test concentration data obtained in S100 for leakage orifice diameters of 5mm and 20mm, an empirical formula for the edge concentration is established.

[0049] For a 5mm leak orifice diameter, the data under various pressure conditions are relatively similar. First, the average concentration values ​​are taken for all pressure conditions at the corresponding locations. For example, for a 5mm leak orifice diameter, the average concentrations at 0.5MPa, 1MPa, 1.5MPa, and 2MPa at a distance of 0.1m from the leak opening are taken, and so on. Then, the calculated average concentration values ​​are used to fit an empirical formula trend line. C 边线5mm = -0.067Ln(x)+0.1152, R 2 = 0.9993 (5) Where x---jet distance, m; C 边线5mm ---Jet concentration at the lower edge of a 5mm leakage orifice diameter.

[0050] Through the above methods, the empirical formula for the edge concentration under a 5mm leakage orifice diameter was obtained.

[0051] For a 20mm leak orifice diameter, the data under various pressure conditions are relatively similar. First, the concentration values ​​are averaged across all pressure conditions at the corresponding locations. For example, for a 20mm leak orifice diameter, the average concentrations at 0.5MPa, 1MPa, 1.5MPa, and 2MPa at a distance of 0.1m from the leak opening are averaged, and so on. Then, the calculated averages are used to fit an empirical formula trend line. C 边线20mm = -0.1298Ln(x)+0.2748, R 2 = 0.9989 (6) Where x---jet distance, m; C 边线20mm ---Concentration of jet flow along the edge under a 20mm leakage condition.

[0052] Through the above methods, the empirical formula for the edge concentration under a 20mm leakage orifice diameter was obtained.

[0053] This embodiment is based on the model construction of actual low-pressure hydrogen jet field experimental test data, which can more accurately reflect the diffusion law after hydrogen leakage and improve the accuracy and reliability of concentration prediction.

[0054] S202. Based on the empirical formulas for jet field concentration under the determined minimum and maximum leakage orifice diameters, construct the jet field concentration prediction model. In S201 of this embodiment, empirical formulas for jet field concentration under the minimum leakage orifice diameter (5mm) and the maximum leakage orifice diameter (20mm) have been obtained, including the empirical formulas for axial concentration, axial centerline concentration, and edgeline concentration. In S202, based on the obtained empirical formulas for axial concentration, axial centerline concentration, and edgeline concentration under the 5mm and 20mm leakage orifice diameters, a jet field concentration prediction model is further constructed. The concentration prediction model based on empirical formulas has a fast calculation speed and can provide prediction results in a short time. This will help decision-makers react quickly and take necessary measures to deal with hydrogen leakage accidents.

[0055] A jet field concentration prediction model is constructed for any leakage orifice diameter between the minimum and maximum leakage orifice diameters. In this embodiment, a jet field concentration prediction model is constructed for any leakage orifice diameter between 5 mm and 20 mm. The jet field concentration prediction model includes an axis concentration prediction model, an axisymmetric centerline concentration prediction model, and an edgeline concentration prediction model.

[0056] Based on the actual situation, construct a relatively detailed or rough prediction model for the concentration of hydrogen leakage jet field in medium and low pressure.

[0057] Specifically, constructing the axis concentration prediction model for any leakage orifice diameter between the minimum and maximum leakage orifice diameters includes determining the location concentration multiple relationship and constructing the axis concentration prediction model based on the location concentration multiple relationship.

[0058] Ignoring concentration differences caused by pressure variations and considering only the effect of the leakage orifice diameter, the concentration ratio relationship at all locations under a 20mm leakage orifice diameter and a 5mm leakage orifice diameter can be expressed as: B 轴线 =0.0382Ln(x)+1.318, R 2 = 0.9997 (7) Where x---jet distance, m; B 轴线 ---Concentration ratios at all locations with a 20mm orifice diameter and a 5mm orifice diameter.

[0059] The leakage orifice diameter between 5mm and 20mm is divided into 15 equal intervals according to a gradient of 1mm, namely 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, and 20mm.

[0060] Based on the empirical formula for axial concentration under a 5mm leakage orifice diameter, the prediction model for axial concentration under a 6mm leakage orifice diameter is as follows: C 轴线6mm =C 轴线5mm ×(B 轴线 / 15) Substituting equations (1) and (7) into the above equation, we get: C 轴线6mm= (-0.13267Ln(x)+0.4083)×(1+((0.0382Ln(x)+1.318)-1)×(1 / 15))(8) Among them, C 轴线6mm ---Axial jet concentration at a 6mm orifice diameter, %.

[0061] By analogy, a jet field axis concentration prediction model can be derived for all leakage orifice sizes.

[0062] The leakage orifice diameter between 5mm and 20mm is divided into five equal parts according to a 3mm gradient: 8mm, 11mm, 14mm, 17mm, and 20mm.

[0063] Based on the empirical formula for axial concentration under a 5mm leakage orifice diameter, the prediction model for axial concentration under an 8mm leakage orifice diameter is as follows: C 轴线8mm =C 轴线5mm ×(B 轴线 / 5) Substituting equations (1) and (7) into the above equation, we get: C 轴线8mm =(-0.13267Ln(x)+0.4083)×(1+((0.0382Ln(x)+1.318)-1)×(3 / 15)) (9) Among them, C 轴线8mm ---Axial jet concentration at an 8mm orifice diameter.

[0064] By analogy, a jet field axis concentration prediction model can be derived for all leakage orifice sizes.

[0065] Specifically, constructing the axial midline concentration prediction model for any leakage orifice diameter between the minimum and maximum leakage orifice diameters includes determining the location concentration multiple relationship and constructing the axial midline concentration prediction model based on the location concentration multiple relationship.

[0066] Ignoring concentration differences caused by pressure variations and considering only the effect of leak diameter, the concentration ratio relationship at all locations under a 20mm leak diameter and a 5mm leak diameter can be expressed as: B 轴侧中线 = 0.0176Ln(x)+1.1782, R 2 = 0.9993 (10) Where x---jet distance, m; B 轴侧中线 ---Concentration ratios at all locations for a 20mm orifice diameter and a 5mm orifice diameter.

[0067] The leakage orifice diameter between 5mm and 20mm is divided into 15 equal intervals according to a gradient of 1mm, namely 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, and 20mm.

[0068] Based on the empirical formula for axial concentration under a 5mm leakage orifice diameter, the prediction model for axial midline concentration under a 6mm leakage orifice diameter is as follows: C 轴侧中线6mm =C 轴侧中线5mm ×(B 轴侧中线 / 15) Substituting equations (3) and (10) into the above equation, we get: C 轴侧中线6mm =(-0.115Ln(x)+0.3583)×(1+((0.0176Ln(x)+1.1782)-1)×(1 / 15))(11) Among them, C 轴侧中线6mm ---Jet concentration at the centerline of the shaft side under a 6mm orifice diameter.

[0069] By analogy, a prediction model for the axial centerline concentration of the jet field can be derived for all leakage orifice sizes.

[0070] The leakage orifice diameter between 5mm and 20mm is divided into five equal parts according to a 3mm gradient: 8mm, 11mm, 14mm, 17mm, and 20mm.

[0071] Based on the empirical formula for axial concentration under a 5mm leakage orifice diameter, the prediction model for axial midline concentration under an 8mm leakage orifice diameter is as follows: C 轴侧中线6mm =C 轴侧中线5mm ×(B 轴侧中线 / 5) Substituting equations (3) and (10) into the above equation, we get: C 轴侧中线6mm =(-0.115Ln(x)+0.3583)×(1+((0.0176Ln(x)+1.1782)-1)×(3 / 15))(12) Among them, C 轴侧中线8m m---Jet concentration at the centerline of the shaft side under an 8mm leakage orifice diameter.

[0072] By analogy, a prediction model for the axial centerline concentration of the jet field can be derived for all leakage orifice sizes.

[0073] Specifically, constructing the edge concentration prediction model for any leakage orifice diameter between the minimum and maximum leakage orifice diameters includes determining the location concentration multiple relationship and constructing the edge concentration prediction model based on the location concentration multiple relationship.

[0074] Ignoring concentration differences caused by pressure variations and considering only the effect of the leakage orifice diameter, the concentration ratio relationship at all locations under a 20mm leakage orifice diameter and a 5mm leakage orifice diameter can be expressed as: B 边线 =0.3959Ln(x)+2.38, R 2 = 0.9919 (13) Where x---jet distance, m; B 边线 ---Concentration ratios at all locations with a 20mm orifice diameter and a 5mm orifice diameter.

[0075] The leakage orifice diameter between 5mm and 20mm is divided into 15 equal intervals according to a gradient of 1mm, namely 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, and 20mm.

[0076] Based on the empirical formula for axial concentration under a 5mm leakage orifice diameter, the prediction model for edge concentration under a 6mm leakage orifice diameter is as follows: C 边线6mm =C 边线5mm ×(B 边线 / 15) Substituting equations (5) and (13) into the above equation, we get: C 边线6mm =(-0.067Ln(x)+0.1152)×(1+((0.3959Ln(x)+2.38)-1)×(1 / 15)) (14) Among them, C 边线6mm ---Jet concentration at the lower edge of a 6mm leakage orifice diameter.

[0077] By analogy, a jet field edge concentration prediction model can be derived for all leakage orifice sizes.

[0078] The leakage orifice diameter between 5mm and 20mm is divided into five equal parts according to a 3mm gradient: 8mm, 11mm, 14mm, 17mm, and 20mm.

[0079] Based on the empirical formula for axial concentration under a 5mm leakage orifice diameter, the prediction model for edge concentration under an 8mm leakage orifice diameter is as follows: C 边线8mm =C 边线5mm ×(B 边线 / 5) Substituting equations (1) and (7) into the above equation, we get: C 边线8mm =(-0.067Ln(x)+0.1152)×(1+((0.3959Ln(x)+2.38)-1)×(3 / 15))(15) Among them, C 边线8mm ---Jet concentration at the lower edge of the 8mm leakage orifice diameter.

[0080] By analogy, a jet field edge concentration prediction model can be derived for all leakage orifice sizes.

[0081] Furthermore, based on a 5mm leakage orifice diameter, the axial concentration prediction model for the medium- and low-pressure hydrogen leakage jet field is obtained as follows: C 轴线Kmm =C 轴线5mm ×(B 轴线 / n)=(-0.13267Ln(x)+0.4083)×(1+(0.0382Ln(x)+1.318)-1)×((K-5) / n))(16) Where x---jet distance, m; n---value is 15; K---leakage orifice diameter (K ​​mm); C 轴线Kmm ---Kmm leakage orifice shape, axial jet concentration,%.

[0082] The prediction model for the axial midline concentration of the medium- and low-pressure hydrogen leakage jet field is as follows: C 轴侧中线Kmm =C 轴侧中线5mm ×(B 轴侧中线 / n)=(-0.115Ln(x)+0.3583)×(1+((0.0176Ln(x)+1.1782)-1)×((K-5) / n))(17) Where x---jet distance, m; n---value is 15; K---leakage orifice diameter (K ​​mm); C 轴侧中线Kmm --- Kmm leakage orifice diameter, centerline jet concentration on the shaft side, %.

[0083] The edge concentration prediction model for the medium- and low-pressure hydrogen leakage jet field is as follows: C 边线Kmm =C 边线5mm ×(B 边线 / n)=(-0.067Ln(x)+0.1152)×(1+((0.3959Ln(x)+2.38)-1)×((K-5) / n))(18) Where x---jet distance, m; n---value is 15; K---leakage orifice diameter (K ​​mm); C 边线Kmm ---Kmm leakage orifice lower edge jet concentration,%.

[0084] In other feasible embodiments, the jet field concentration prediction model can also be constructed based on a maximum leakage orifice diameter of 20 mm.

[0085] This embodiment constructs hydrogen leakage jet field concentration prediction models for 5mm leakage orifice diameter, 20mm leakage orifice diameter, and medium-low pressure (pressure 2MPa and below) leakage orifice diameters between 5-20mm. The constructed jet field concentration prediction model is applicable to concentration prediction under different leakage orifice diameter conditions. It can not only be used for leakage jet field concentration prediction under specific 5mm and 20mm leakage orifice diameters, but also for leakage jet field concentration prediction under intermediate leakage orifice diameters (5-20mm), greatly enhancing the model's generalization ability and adaptability, making it more flexible and practical in real-world applications.

[0086] Based on the aforementioned axis concentration prediction model, axisymmetric centerline concentration prediction model, and edgeline concentration prediction model, the concentration of hydrogen leakage in the jet field under medium and low pressure is predicted. The jet field concentration prediction model of this embodiment can quickly provide concentration prediction results, offering timely and effective reference for emergency response.

[0087] The prediction method of this invention can provide technical support for the rapid acquisition of the concentration characteristics of low-pressure hydrogen leakage jet field in hydrogen-related sites. After a low-pressure hydrogen leakage occurs in a hydrogen-related site, it can provide data on the concentration distribution characteristics of hydrogen at the leakage site in a simple, fast and accurate manner, thereby enabling targeted hydrogen leakage prevention and control measures to be taken.

[0088] Example 3 As a specific embodiment of the present invention, this embodiment provides a method for predicting the concentration of hydrogen leakage jet field in medium and low pressure. Based on Embodiment 2, the prediction model for the concentration of hydrogen leakage jet field in medium and low pressure is verified.

[0089] This embodiment uses 7mm, 9mm, and 15mm leaking orifice diameters as examples to predict the concentration of hydrogen leakage jet field in medium- and low-pressure conditions with a 1mm equal spacing. It verifies the medium- and low-pressure hydrogen leakage jet field concentration prediction model constructed in Embodiment 2. Figure 2-4 As shown, where Figure 2 This is a graph showing the changes in the concentration along the axis. Figure 3 This is a graph showing the changes in concentration along the midline of the axial axis. Figure 4 This is a graph showing the change in the concentration of the boundary line.

[0090] from Figure 2 It can be seen that the predicted axial concentration distributions under leakage orifice diameters of 7mm, 9mm, and 15mm are all within the range of the 5mm and 20mm curves obtained through experiments, and the trends are similar, showing a gradual decrease and narrowing trend, which is more in line with the actual situation.

[0091] from Figure 3 It can be seen that the predicted axial midline concentration distribution under leakage orifice diameters of 7mm, 9mm, and 15mm is mostly within the range of the 5mm and 20mm curves obtained through experiments, and the trends are similar, showing a gradual decrease and narrowing trend, which is more in line with the actual situation.

[0092] from Figure 4 It can be seen that the predicted edge concentration distributions at leakage orifice diameters of 7mm, 9mm, and 15mm, except for the ultra-close distance of 0.1m which is slightly smaller, are mostly within the range of the 5mm and 20mm curves obtained through experiments, and the trends are similar, showing a gradual decrease and narrowing trend, which is more in line with the actual situation.

[0093] Furthermore, the experimental concentration data of medium and low pressure hydrogen jet field under a 10mm leakage aperture obtained in Example 2 was used as a test set to verify the constructed concentration prediction model of medium and low pressure hydrogen leakage jet field under a 5-20mm aperture. The performance of the model was evaluated by comparing the test set and the prediction results.

[0094] This embodiment validates the constructed concentration prediction model for medium- and low-pressure hydrogen leakage jet fields. The results calculated by the model are consistent with the actual situation and have high reference value for engineering decision-making. Furthermore, the model is simple to calculate and can provide excellent support for the rapid and relatively accurate prediction of the concentration field in the event of medium- and low-pressure hydrogen leakage at the engineering site.

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A method for predicting the concentration of hydrogen leakage jet field in medium and low pressure systems, characterized in that, The method includes: Obtain experimental concentration data for medium- and low-pressure hydrogen jet fields; Based on the obtained experimental concentration data of the medium and low pressure hydrogen jet field, a jet field concentration prediction model is constructed. Based on the constructed jet field concentration prediction model, the concentration of the hydrogen leakage jet field in medium and low pressure is predicted.

2. The method for predicting the concentration of hydrogen leakage jet field under medium and low pressure according to claim 1, characterized in that, The acquisition of experimental concentration data for medium and low pressure hydrogen jet fields includes acquiring experimental concentration data for medium and low pressure hydrogen jet fields under different leakage orifice diameters, including the minimum leakage orifice diameter and the maximum leakage orifice diameter.

3. The method for predicting the concentration of hydrogen leakage jet field under medium and low pressure according to claim 1, characterized in that, The step of constructing a jet field concentration prediction model based on the obtained experimental concentration data of the medium and low pressure hydrogen jet field includes determining the empirical formulas for jet field concentration under the minimum leakage orifice diameter and the maximum leakage orifice diameter, and constructing the jet field concentration prediction model based on the determined empirical formulas for jet field concentration under the minimum leakage orifice diameter and the maximum leakage orifice diameter.

4. The method for predicting the concentration of hydrogen leakage jet field under medium and low pressure according to claim 3, characterized in that, The empirical formula for jet field concentration includes at least one of the empirical formulas for axial concentration, axial centerline concentration, and edgeline concentration. The jet field concentration prediction model is constructed based on at least one of the empirical formulas for axial concentration, axial centerline concentration, and edgeline concentration.

5. The method for predicting the concentration of hydrogen leakage jet field at medium and low pressure according to claim 3, characterized in that, The empirical formula for determining the jet field concentration under the minimum and maximum leakage orifice diameters includes averaging the concentration under all pressure conditions at the same distance from the leakage orifice, and fitting the empirical formula trend line using the calculated average concentration value.

6. The method for predicting the concentration of hydrogen leakage jet field at medium and low pressure according to claim 5, characterized in that, The step of constructing the jet field concentration prediction model based on the empirical formula for jet field concentration under the determined minimum and maximum leakage orifice diameters includes determining the location concentration multiple relationship and constructing the jet field concentration prediction model based on the empirical formula for jet field concentration under the minimum and / or maximum leakage orifice diameters.

7. The method for predicting the concentration of hydrogen leakage jet field at medium and low pressure according to claim 6, characterized in that, The jet field concentration prediction model includes at least one of the axis concentration prediction model, the axisymmetric centerline concentration prediction model, and the edgeline concentration prediction model. Based on the determined position concentration multiple relationship, the corresponding jet field concentration prediction model is constructed according to at least one of the axis concentration empirical formula, the axisymmetric centerline concentration empirical formula, and the edgeline concentration empirical formula.

8. The method for predicting the concentration of hydrogen leakage jet field under medium and low pressure according to claim 6, characterized in that, The jet field concentration prediction model includes at least one of the following models: C 轴线Kmm =(-0.13267Ln(x)+0.4083)×(1+(0.0382Ln(x)+1.318)-1)×((K-j) / n)); C 轴侧中线Kmm =(-0.115Ln(x)+0.3583)×(1+((0.0176Ln(x)+1.1782)-1)×((K-j) / n)); C 边线Kmm = (-0.067Ln(x)+0.1152)×(1+((0.3959Ln(x)+2.38)-1)×((K-j) / n)); Where x is the jet distance, m; n is the number of equal divisions between the minimum and maximum leakage orifice diameters; j is the minimum leakage orifice diameter, mm; K is the leakage orifice diameter, greater than or equal to j, mm; C 轴线Kmm ---K leakage orifice shape, axial jet concentration, C 轴侧中线Kmm --- K leakage orifice diameter, centerline jet concentration on the shaft side, C 边线Kmm ---K leakage orifice lower edge jet concentration,%.

9. The method for predicting the concentration of hydrogen leakage jet field at medium and low pressure according to claim 3, characterized in that, The minimum leakage orifice diameter is 5 mm, and the maximum leakage orifice diameter is 20 mm.

10. The method for predicting the concentration of hydrogen leakage jet field in medium and low pressure according to claim 1, characterized in that, The medium and low pressure refers to a pressure value of 2 MPa and below.

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