Method for obtaining pre-processing parameters for hydrogen pipeline erosion analysis

Abstract

The application discloses a method for obtaining hydrogen pipeline erosion analysis preprocessing parameters, and belongs to the technical field of hydrogen transportation. The method replaces a natural gas pipeline with a hydrogen pipeline, and comprises the following steps: obtaining parameters of a natural gas pipeline to be replaced, so as to establish a hydrogen pipeline flow rate calculation model; obtaining solid impurity carrying flow of the natural gas pipeline under different test time and different cross-section test points; and calculating the maximum mass flow of the solid impurities according to the natural gas pipeline and the hydrogen pipeline after energy equivalence, and obtaining the solid impurity flow of the hydrogen pipeline after energy equivalence. The application can provide erosion flow rate evaluation technical support for a hydrogen conveying pipeline with solid particles.

Description

Technical Field

[0001] This application belongs to the field of hydrogen transportation technology, and in particular relates to a method for obtaining pretreatment parameters for hydrogen pipeline erosion analysis. Background Technology

[0002] Hydrogen, as a key development direction for new energy sources, boasts significant advantages over traditional fossil fuels, including high calorific value, environmentally friendly combustion products, wide availability, and renewability. It is hailed as a clean energy source of the future and will become a new pathway for humanity to address increasingly severe energy and environmental challenges. Hydrogen transportation is a crucial link in hydrogen energy utilization. Utilizing reliable pipelines to connect hydrogen sources with target users is key to optimizing energy consumption and promoting hydrogen energy utilization. With the gradual stabilization of upstream hydrogen sources and the increasing downstream hydrogen consumption, the prospects for hydrogen pipeline transportation are promising.

[0003] Currently, existing technologies have proposed methods for evaluating the flow velocity in hydrogen pipelines. ASME B31.12, "Hydrogen Piping and Pipelines," presents a formula for calculating the maximum erosion velocity in hydrogen pipelines. This formula is primarily inversely proportional to the medium density; that is, the higher the medium density and the higher the operating pressure, the lower the allowable erosion velocity. However, this formula does not fully reveal the impact of solid impurities on the allowable erosion velocity. Furthermore, this method mainly targets pipelines in open-air stations and does not specify requirements for the erosion velocity of buried pipelines, and it is not applicable to operating pipelines containing solid impurities. Summary of the Invention

[0004] The purpose of this application is to overcome the deficiencies of the prior art by providing a method for obtaining pre-processing parameters for hydrogen pipeline erosion analysis, obtaining the flow rate of solid impurities as a pre-processing input parameter for existing evaluation methods, and making up for the shortcomings and deficiencies of existing standard methods.

[0005] The objective of this application is achieved through the following technical solution:

[0006] This invention provides a method for obtaining preprocessing parameters for erosion analysis of hydrogen pipelines, wherein the method uses the hydrogen pipeline instead of a natural gas pipeline, and the method includes the following steps:

[0007] S1. Obtain the parameters of the natural gas pipeline to be replaced in order to establish a flow velocity calculation model for the hydrogen pipeline;

[0008] S2. Obtain the flow rate of solid impurities carried by the natural gas pipeline at different test times and test points with different cross sections;

[0009] S3. Based on the throughput and flow rate of the natural gas pipeline and the energy-equivalent hydrogen pipeline, calculate the maximum mass flow rate of solid impurities, and obtain the flow rate of solid impurities transported by the energy-equivalent hydrogen pipeline.

[0010] Furthermore, in step S1, the parameters of the natural gas pipeline to be replaced include the inner diameter of the natural gas pipeline, the natural gas pipeline throughput, and the minimum operating pressure of the natural gas pipeline.

[0011] Furthermore, in step S1, the establishment of the hydrogen pipeline flow velocity calculation model includes calculating the flow velocity of the replaced hydrogen pipeline using the minimum operating pressure of the replaced hydrogen pipeline and the unit volume calorific value of natural gas and hydrogen.

[0012] Furthermore, in step S2, obtaining the solid impurity carrying flow rate of the natural gas pipeline at different test times and different cross-sectional test points includes the following steps:

[0013] Natural gas was sampled from different locations on the pipeline cross-section and tested. The total volume of the sampled gas and the total volumetric flow rate at each sampling point during each sampling process were recorded. The mass of impurities carried by the sampled gas was also recorded.

[0014] The average solid impurity concentrations of the sampled gas at different sampling points are ranked, and the highest average solid impurity concentration is selected as the solid impurity concentration of the natural gas pipeline for energy substitution, thereby obtaining the solid impurity flow rate of the natural gas pipeline.

[0015] Furthermore, in step S3, the specific steps for calculating the maximum mass flow rate of solid impurities based on the throughput and velocity of the natural gas pipeline and the energy-equivalent hydrogen pipeline are as follows:

[0016] The solid impurity flow rate of the natural gas pipeline is compared with the maximum solid impurity carrying capacity of the natural gas pipeline to obtain the solid impurity carrying ratio.

[0017] When the solid impurity carrying ratio is less than the first preset threshold, the solid impurity flow rate of the natural gas pipeline before replacement is used as the solid impurity flow rate of the hydrogen pipeline.

[0018] When the solid impurity carrying ratio is greater than the first preset threshold, the solid impurity flow rate of the hydrogen pipeline is calculated based on the maximum solid carrying capacity of the hydrogen pipeline.

[0019] Furthermore, in step S3, the method for obtaining the maximum solid impurity carrying capacity of the natural gas pipeline includes:

[0020] A model for the maximum solid impurity carrying capacity in natural gas pipelines is established using the Rizk solids carryover prediction method.

[0021] The maximum solid impurity carrying capacity of a natural gas pipeline at the corresponding flow velocity and density is calculated based on the model of maximum solid impurity carrying capacity of the natural gas pipeline.

[0022] Furthermore, the method also includes:

[0023] The sampled gas is filtered through a filter before testing.

[0024] Furthermore, the mass of the impurities carried by the body is obtained by weighing the mass of the filtered solid.

[0025] Furthermore, in step S1, the parameters of the natural gas pipeline to be replaced are obtained to establish a flow velocity calculation model for the hydrogen pipeline. The specific steps are as follows:

[0026] S11. Obtain the following parameter: the inner diameter D of the natural gas pipeline of the energy substitution target. N Natural gas pipeline transport capacity Q, the energy substitution target N The minimum operating pressure P of the natural gas pipeline used for energy substitution N Minimum operating pressure P of hydrogen pipeline after energy substitution H The calorific value (H) per unit volume of natural gas (represented by methane) and hydrogen. N and H H ;

[0027] S12. After obtaining the above parameters, calculate the standard volumetric hydrogen pipeline transport capacity Q after energy substitution. H :

[0028]

[0029] In the formula, Q N This refers to the volumetric transport capacity of natural gas pipelines, in meters (m). 3 / d;Q H This refers to the volumetric flow rate of hydrogen in the pipeline, in meters (m). 3 / d;H N This refers to the calorific value of natural gas per unit volume, expressed in kJ / m³. 3 H H This is the calorific value per unit volume of hydrogen, expressed in kJ / m³. 3 ;

[0030] S13. The simplified formula for calculating the maximum operating flow velocity of a natural gas pipeline is:

[0031]

[0032] In the formula, P N The minimum operating pressure for natural gas pipelines, expressed in barg; D N The inner diameter of the natural gas pipeline is in mm; v N The maximum flow velocity in the natural gas pipeline is expressed in m / s.

[0033] S14. Calculate the hydrogen pipeline flow rate after energy substitution:

[0034]

[0035] In the formula, P H This is the minimum operating pressure for hydrogen pipelines, expressed in barg; v H The maximum flow velocity of hydrogen in the pipeline after energy substitution is expressed in m / s.

[0036] Therefore, by utilizing the basic information of the pipeline before and after energy substitution, natural gas pipeline data, and the calorific value and physical properties of natural gas and hydrogen, the volumetric throughput of the hydrogen pipeline based on energy equivalent substitution can be calculated, and a formula for calculating the flow velocity of the hydrogen pipeline based on the minimum operating pressure (variable) of the hydrogen pipeline can be further established.

[0037] Furthermore, in step S2, an online multi-point sampling device is set up on the natural gas pipeline to draw natural gas from different positions on the pipeline cross-section to the testing system. The gas at each point is discharged after gas volume measurement and filtration. The following data is recorded and tested: (1) The total volume Q of the sampled and filtered gas. n,x , represents the total volumetric flow rate of the gas sampled at sampling point n during the xth sampling process; (2) the mass of the filtered solid is obtained by weighing, and is denoted as M. n,x , representing the total mass of impurities filtered by sampling point n during the xth sampling process.

[0038] Therefore, the average solid impurity volume content at the nth sampling point can be calculated and denoted as m. n :

[0039]

[0040] In the formula, M n,x Q represents the mass of solids filtered during the x-th filtration at sampling point n in a natural gas pipeline, in kg. n,x The volume of natural gas introduced into the pipeline during the x-th filtration process at sampling point n, in cubic meters (m³). 3 M n The average solid impurity concentration at sampling point n in the natural gas pipeline, in kg / m³. 3 ;

[0041] The average solid impurity concentrations at different sampling points n were ranked, and the highest average solid impurity concentration was selected as the solid impurity concentration m of the natural gas pipeline for energy substitution. A Therefore, the solid impurity flow rate q of the natural gas pipeline can be obtained. N .

[0042] q N =Q N ×m A (5)

[0043] In the formula, m A The concentration of solid impurities in natural gas pipelines used as energy substitutes, in kg / m³.3 ;q N The flow rate of solid impurities in natural gas pipelines used as an energy substitute is expressed in kg / s.

[0044] Furthermore, in step S3, to calculate the maximum carrying capacity (mass flow rate) of solid impurities based on the target natural gas pipeline and the energy-equivalent hydrogen pipeline's transport capacity and flow rate, and to obtain the energy-equivalent hydrogen pipeline's solid impurity flow rate, the specific method is as follows:

[0045] S31. Using the Rizk solids carryover prediction method, establish a model for the maximum solids carryover capacity of natural gas pipelines:

[0046]

[0047] In the formula, W N The maximum solid impurity carrying capacity of a natural gas pipeline is expressed in kg / s; A is the cross-sectional area of ​​the pipeline, in m². 2 ;v N ρ is the flow velocity of natural gas in m / s. N The density of the medium under operating conditions of a natural gas pipeline, in kg / m³. 3 dp represents the particle size of the solid particles, in meters (m).

[0048] S32. The flow rate q of solid impurities in the natural gas pipeline obtained in step S2. N W with the maximum solid impurity carrying capacity of natural gas pipelines N The solid impurity carrying ratio R was obtained by comparison. N :

[0049]

[0050] In the formula, R N The solid impurity carry-over ratio of natural gas pipelines, in %;

[0051] When the solid impurity carrying ratio R N When the percentage is less than 50%, it indicates that all solid impurities in the original natural gas pipeline can be completely carried by the gas. It is assumed that the flow rate of solid impurities transported by the hydrogen pipeline is the same as the flow rate of solid impurities in the natural gas pipeline before energy substitution, and the flow rate of solid impurities transported by the hydrogen pipeline is obtained.

[0052] When the solid impurity carrying ratio R N When the solid impurities in the original natural gas pipeline exceed 50%, it indicates that there is a risk that the solid impurities in the original natural gas pipeline cannot be completely carried away. Therefore, the solid impurity flow rate transported by the hydrogen pipeline may be higher than the solid impurity flow rate of the natural gas pipeline before energy substitution. Therefore, the solid impurity flow rate of the hydrogen pipeline after energy substitution is further calculated by using the maximum solid carrying capacity of the hydrogen pipeline.

[0053] S33. Since the presence of solid impurities in hydrogen pipelines is lower than that in natural gas pipelines, a solid impurity flow rate correction factor S is introduced to correct the solid impurity flow rate in hydrogen pipelines, as follows:

[0054]

[0055] In the formula,

[0056] W H The amount of solid impurities carried by the hydrogen pipeline (corrected), in kg / s;

[0057] v H The velocity of hydrogen gas in the pipeline is expressed in m / s.

[0058] ρ H The density of the medium under operating conditions of the hydrogen pipeline, in kg / m³ 3 ;

[0059] S is the correction factor for the flow rate of solid impurities in the hydrogen pipeline.

[0060] This yielded the flow rate of solid impurities in the hydrogen pipeline, providing crucial input parameter preprocessing for subsequent pipeline erosion calculations.

[0061] The beneficial effects of this application are as follows:

[0062] Based on the background of hydrogen replacing natural gas pipelines as an energy substitute, this application proposes a hydrogen pipeline flow velocity calculation model based on the influence of operating pressure. Taking the impurity content in the actual operation of the equivalent natural gas pipeline as a benchmark, it proposes an online impurity measurement and impurity flow calculation method based on multiple points. Combining the gas pipeline impurity carrying capacity evaluation model, and based on the physical properties of natural gas and hydrogen, it establishes a criterion for judging the ratio of natural gas solid impurity flow rate to maximum carrying capacity, and proposes two methods for calculating the solid impurity flow rate of hydrogen pipelines for energy substitution, providing the most direct preprocessing parameters for subsequent hydrogen pipeline erosion analysis. Attached Figure Description

[0063] Figure 1 This is a flowchart of a method for obtaining preprocessing parameters for hydrogen pipeline erosion analysis according to an embodiment of this application. Detailed Implementation

[0064] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0065] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0066] Existing methods for evaluating hydrogen pipeline flow velocity cannot fully reveal the impact of solid impurities on permissible erosion velocities. Furthermore, existing technologies primarily target pipelines in open-air stations, failing to address erosion velocities in buried pipelines and are not applicable to operating pipelines containing solid impurities.

[0067] To address the aforementioned technical problems, the following embodiments of a method for obtaining preprocessing parameters for hydrogen pipeline erosion analysis are proposed in this application.

[0068] Example 1

[0069] Compared to natural gas, hydrogen has a calorific value of about 1 / 3 and a density of about 1 / 8 of natural gas under standard operating conditions (101.325 kPa, 20℃). If the same volumetric transmission rate (under standard operating conditions) is used, the energy transmission efficiency of the pipeline will inevitably be greatly reduced. Therefore, to effectively improve the energy transmission efficiency of the pipeline, it is advisable to increase the pipeline transmission rate (under standard operating conditions), specifically including: (1) increasing the pipeline operating speed under the same operating pressure; (2) increasing the pipeline operating pressure under the same operating speed. However, in the operation of some natural gas pipelines, pipeline corrosion problems have occurred due to the failure of the water dew point to meet the standards, and there are still certain construction residue solids after the pipeline is put into operation, resulting in solid impurities in the pipeline. For hydrogen pipelines, the risk of pipeline corrosion caused by the components entering the pipeline is relatively small. This provides certain favorable conditions for the transmission of energy such as hydrogen and natural gas, but a quantitative evaluation method needs to be proposed.

[0070] Reference Figure 1 ,like Figure 1 The diagram shown is a flowchart of a method for obtaining preprocessing parameters for erosion analysis of a hydrogen pipeline according to an embodiment of this application. This method uses a hydrogen pipeline instead of a natural gas pipeline and specifically includes the following steps:

[0071] Step 1: Obtain the parameters of the natural gas pipeline to be replaced in order to establish a flow velocity calculation model for the hydrogen pipeline.

[0072] Specifically, key parameters such as pipe diameter, volumetric flow rate (standard operating conditions), and minimum pressure of the target natural gas pipeline are collected; with energy substitution as the goal, a method for calculating the flow velocity of hydrogen pipelines with the minimum operating pressure of hydrogen pipelines as the variable is established, and the maximum flow velocity of hydrogen pipelines is determined.

[0073] (1) The inner diameter D of the natural gas pipeline for energy substitution N ;

[0074] (2) Natural gas pipeline transport capacity Q of the energy substitution target N ;

[0075] (3) Minimum operating pressure P of the natural gas pipeline for energy substitution N ;

[0076] (4) Minimum operating pressure P of the hydrogen pipeline after energy substitution H ;

[0077] (5) Calorific value (H) per unit volume of natural gas (represented by methane) and hydrogen N and H H ;

[0078] First, after obtaining the above parameters, the standard volumetric flow rate Q of the hydrogen pipeline after energy substitution is calculated. H :

[0079]

[0080] In the formula,

[0081] Q N —Volume transport capacity of natural gas pipelines, m3 / d;

[0082] Q H —Hydrogen pipeline volumetric throughput, m³ / d;

[0083] H N —The calorific value of natural gas per unit volume, kJ / m³ 3 ;

[0084] H H —The calorific value of hydrogen per unit volume, kJ / m³ 3 ;

[0085] Subsequently, the maximum operating flow rate of the natural gas pipeline is calculated, and the simplified formula is as follows;

[0086]

[0087] In the formula,

[0088] P N —Minimum operating pressure of natural gas pipelines, in barg;

[0089] D N —Inner diameter of natural gas pipeline, mm;

[0090] v N —The maximum flow velocity in a natural gas pipeline, in m / s;

[0091] Next, calculate the hydrogen pipeline flow rate after energy substitution;

[0092]

[0093] In the formula,

[0094] P H —Minimum operating pressure of hydrogen pipelines, barg;

[0095] v H —The highest flow velocity of the hydrogen pipeline after energy substitution, in m / s;

[0096] Therefore, by utilizing the basic information of the pipeline before and after energy substitution, natural gas pipeline data, and the calorific value and physical properties of natural gas and hydrogen, the volumetric throughput of the hydrogen pipeline based on energy equivalent substitution can be calculated, and a formula for calculating the flow velocity of the hydrogen pipeline based on the minimum operating pressure (variable) of the hydrogen pipeline can be further established.

[0097] Step 2: Obtain the flow rate of solid impurities carried by natural gas pipelines at different test times and test points with different cross-sections.

[0098] Specifically, an online testing method is used to obtain the solid impurity carrying flow rate of the target substitute natural gas pipeline at different test times and test points with different cross sections, which is used to obtain the average value of the benchmark solid impurity content based on time and pipeline cross-sectional location.

[0099] A cross-sectional online multi-point sampling device is installed on the natural gas pipeline. Natural gas is drawn from different positions on the pipeline cross-section to the testing system. The gas at each point is discharged after gas volume measurement and filtration (preferably 0.5μm). The following data is recorded and tested: (1) The total volume Q of the sampled and filtered gas. n,x , represents the total volumetric flow rate of the gas sampled at sampling point n during the xth sampling process; (2) the mass of the filtered solid is obtained by weighing, and is denoted as M. n,x , representing the total mass of impurities filtered by sampling point n during the xth sampling process.

[0100] Therefore, the average solid impurity volume content at the nth sampling point can be calculated and denoted as m. n :

[0101]

[0102] In the formula,

[0103] M n,x —The mass of solids filtered during the xth filtration at sampling point n in the natural gas pipeline, in kg;

[0104] Q n,x —The volume of natural gas introduced into the pipeline during the x-th filtration process at sampling point n, in m 3 ;

[0105] m n —The average concentration of solid impurities at sampling point n in the natural gas pipeline, kg / m³ 3 ;

[0106] Furthermore, the average solid impurity concentrations at different sampling points n are ranked, and the highest average solid impurity concentration is selected as the solid impurity concentration m of the natural gas pipeline for energy substitution. A Therefore, the solid impurity flow rate q of the natural gas pipeline can be obtained. N .

[0107] q N =Q N ×m A (5)

[0108] In the formula,

[0109] m A —Concentration of solid impurities in natural gas pipelines as energy substitutes, kg / m 3 ;

[0110] q N —Flow rate of solid impurities in natural gas pipelines as an energy substitute, kg / s.

[0111] Since hydrogen pipelines are largely free from internal corrosion, the absolute value of solid impurities in them can be considered smaller than that in natural gas pipelines. Therefore, it is assumed that the flow rate of solid impurities transported by hydrogen pipelines is the same as that of solid impurities in natural gas pipelines before energy substitution.

[0112] Step 3: Calculate the maximum mass flow rate of solid impurities based on the throughput and velocity of the natural gas pipeline and the energy-equivalent hydrogen pipeline, and obtain the flow rate of solid impurities transported by the energy-equivalent hydrogen pipeline.

[0113] Specifically, based on the target natural gas pipeline's throughput and flow rate, the maximum carrying capacity (mass flow rate) of solid impurities is calculated. The ratio of the actual solid mass flow rate to the maximum carrying capacity is calculated, and the concept of a critical carrying ratio is proposed. When the critical ratio is less than 50%, it indicates that the actual solids are completely carried and will not increase with the increase of flow rate, and the target hydrogen pipeline can use the same mass flow rate. When the critical ratio is greater than 50%, it indicates that the actual solid flow rate is high, and the maximum carrying capacity of the hydrogen pipeline should be considered as the corrected maximum carrying capacity. A formula for calculating the corrected maximum carrying capacity is also proposed.

[0114] As one implementation method, this application can use the Rizk solids carryover prediction method to establish a model for the maximum solids carryover capacity of natural gas pipelines:

[0115]

[0116] In the formula,

[0117] W N —Maximum solid impurity carrying capacity of natural gas pipelines, kg / s;

[0118] A – Pipe cross-sectional area, m² 2 ;

[0119] v N —Natural gas flow rate, m / s;

[0120] ρ N —The density of the medium under natural gas pipeline operating conditions, kg / m3;

[0121] dp — particle size of solid particles, in meters.

[0122] The model's calculation results represent the maximum carrying capacity of gas for solid impurities at corresponding flow velocities and densities. Therefore, the solid impurity flow rate q obtained in step two for the natural gas pipeline is... N W with the maximum solid impurity carrying capacity of natural gas pipelines N The solid impurity carrying ratio R was obtained by comparison. N :

[0123]

[0124] In the formula,

[0125] R N — Solid impurity carryover ratio of natural gas pipelines, %.

[0126] When the solid impurity carrying ratio R NWhen the percentage is less than 50%, it indicates that all solid impurities in the original natural gas pipeline can be completely carried by the gas. It can be conservatively assumed that the flow rate of solid impurities transported by the hydrogen pipeline is the same as the flow rate of solid impurities in the natural gas pipeline before energy substitution, and the flow rate of solid impurities transported by the hydrogen pipeline can be obtained.

[0127] When the solid impurity carrying ratio R N When the solid impurity rate exceeds 50%, it indicates that there is a risk that the solid impurities in the original natural gas pipeline cannot be completely carried away. Therefore, the solid impurity flow rate transported by the hydrogen pipeline may be higher than that of the natural gas pipeline before energy substitution. Therefore, the solid impurity flow rate of the hydrogen pipeline after energy substitution is further calculated based on the maximum solid carrying capacity of the hydrogen pipeline.

[0128] Since the presence of solid impurities in hydrogen pipelines is less pronounced than in natural gas pipelines, a solid impurity flow rate correction factor S is introduced to correct for the solid impurity flow rate in hydrogen pipelines, as follows:

[0129]

[0130] In the formula,

[0131] W H —Solid impurity carryover rate in hydrogen pipeline (corrected), kg / s;

[0132] v H — Hydrogen gas flow velocity in the pipeline, m / s;

[0133] ρ H —Density of the medium under operating conditions of hydrogen pipeline, kg / m3;

[0134] S—the correction coefficient for the flow rate of solid impurities in the hydrogen pipeline, preferably 0.7.

[0135] This yielded the flow rate of solid impurities in the hydrogen pipeline, providing crucial input parameter preprocessing for subsequent pipeline erosion calculations.

[0136] This method allows for the calculation of flow velocity in hydrogen pipelines using energy equivalence. Combined with test data on solid impurity content in natural gas pipelines before energy substitution, a preliminary screening of solid impurity flow rates (preliminary screening values) is obtained for hydrogen pipeline erosion analysis. Furthermore, by comparing the tested solid impurity flow rates with the maximum solid impurity carrying capacity, the concept of a critical carrying ratio is proposed. Two categories are distinguished between the actual solid impurity flow rate and the maximum solid impurity carrying capacity ratio. The existence of solid impurity sources in hydrogen pipelines is further considered, leading to a revised maximum solid impurity carrying capacity for hydrogen pipelines. In summary, the preprocessing method proposed in this invention fills the gaps in existing standards for obtaining key parameters for hydrogen erosion rate evaluation, providing crucial technical references for the development of key energy transportation technologies such as hydrogen and natural gas pipelines.

[0137] The principle of the method in this embodiment is as follows:

[0138] (1) Hydrogen, as one of the important development directions of new energy, has significant advantages over traditional fossil fuels, including non-polluting combustion products, wide availability, and renewability. It is considered a clean energy source of the future and will become a new way for humanity to solve increasingly serious energy and environmental problems. Hydrogen transportation is a crucial link in hydrogen energy utilization. Using reliable pipeline transportation to connect hydrogen sources and target users is key to optimizing energy consumption and promoting hydrogen energy utilization. Pipeline transportation is an important scenario for the large-scale application of hydrogen in the future.

[0139] Compared to natural gas (whose main component is methane), hydrogen has a density of about 1 / 8 and a calorific value per unit volume of about 1 / 3. Therefore, from the perspective of energy substitution, it is essential to increase the operating flow rate of hydrogen pipelines.

[0140] (2) With increased pipeline flow velocity, the erosion capacity caused by solid impurities carried by the pipeline medium may increase. This depends primarily on the medium's ability to tumble or suspend solid impurities, the density relationship between the medium and the solid impurities, and the mass flow rate of the solid impurities. Existing hydrogen-related specifications propose erosion rates based on API RP 14E corrections, mainly considering the impact of hydrogen itself on the pipeline system, but not the erosion effect of solid impurities in the medium. In reality, solid impurities still have a certain impact in the operation of long-distance natural gas purification pipelines, mainly from construction residues and surface corrosion products after long-term pipeline operation. Therefore, it is necessary to study methods for evaluating the erosion of hydrogen pipelines containing impurities, providing support for the selection of hydrogen flow velocity. Its essence is to solve the problem of calculating and determining the flow rate of solid impurities in current erosion models containing impurities.

[0141] (3) The volume of hydrogen pipelines that replace natural gas pipelines for energy is mainly affected by the transmission pressure and the transmission velocity. Therefore, with the goal of equal calorific value, a method for calculating the flow velocity of hydrogen pipelines based on the influence of pressure was established to meet the energy replacement of natural gas pipelines.

[0142] (4) Since there is far more operational experience with natural gas pipelines than with hydrogen pipelines, and the sources of solid particles in natural gas pipelines are more diverse than those in hydrogen, this invention proposes to use the actual solid-carrying flow rate of natural gas pipelines as the basis for evaluating the solid-carrying flow rate of hydrogen pipelines of the same diameter. Compared with the traditional method of separating and weighing solid impurities from the station filter separator, this invention proposes an online multi-point gas sampling scheme to reduce the minimum allowable particle size, comprehensively calculate and screen the maximum solid-carrying flow rate of natural gas pipelines before energy substitution, and use this as the initial solid-carrying flow rate of hydrogen pipelines after energy substitution.

[0143] (5) In the pipeline, solid impurities are carried by gas through tumbling, suspension and other means. In order to rule out whether the solid impurities obtained by the test in the natural gas pipeline have reached the maximum carrying capacity of the gas for impurities, a comparative analysis simulation and evaluation standard based on the actual solid impurity flow rate and the maximum solid impurity flow rate was established to further determine the rationality of the selected solid impurity flow rate. At the same time, considering the existence of impurities in the hydrogen pipeline, a solid impurity flow rate correction coefficient was introduced to correct the solid impurity capacity of the hydrogen pipeline when the ratio of the solid impurity flow rate measured in the natural gas pipeline to the maximum solid impurity flow rate exceeds the solid impurity carrying ratio. This correction coefficient is used as the solid impurity carrying flow rate of the hydrogen pipeline. Furthermore, a method for calculating the solid impurity carrying flow rate of hydrogen pipeline with equal energy transmission was proposed, forming the most critical solid impurity flow rate preprocessing parameter for the solid erosion analysis of hydrogen pipeline.

[0144] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for obtaining preprocessing parameters for hydrogen pipeline erosion analysis, characterized in that, The method replaces the natural gas pipeline with the hydrogen pipeline, and the method includes the following steps: S1. Obtain the parameters of the natural gas pipeline to be replaced in order to establish a flow velocity calculation model for the hydrogen pipeline; S2. Obtain the flow rate of solid impurities carried by the natural gas pipeline at different test times and test points with different cross sections; S3. Based on the throughput and flow rate of the natural gas pipeline and the energy-equivalent hydrogen pipeline, calculate the maximum mass flow rate of solid impurities, and obtain the flow rate of solid impurities transported by the energy-equivalent hydrogen pipeline.

2. The method for obtaining preprocessing parameters for hydrogen pipeline erosion analysis as described in claim 1, characterized in that, In step S1, the parameters of the natural gas pipeline to be replaced include the inner diameter of the natural gas pipeline, the natural gas pipeline throughput, and the minimum operating pressure of the natural gas pipeline.

3. The method for obtaining preprocessing parameters for hydrogen pipeline erosion analysis as described in claim 2, characterized in that, In step S1, the establishment of the hydrogen pipeline flow velocity calculation model includes calculating the flow velocity of the replaced hydrogen pipeline based on the minimum operating pressure of the replaced hydrogen pipeline and the unit volume calorific value of natural gas and hydrogen.

4. The method for obtaining preprocessing parameters for hydrogen pipeline erosion analysis as described in claim 1, characterized in that, In step S2, obtaining the solid impurity carrying flow rate of the natural gas pipeline at different test times and different cross-sectional test points includes the following steps: Natural gas was sampled from different locations on the pipeline cross-section and tested. The total volume of the sampled gas and the total volumetric flow rate at each sampling point during each sampling process were recorded. The mass of impurities carried by the sampled gas was also recorded. The average solid impurity concentrations of the sampled gas at different sampling points are ranked, and the highest average solid impurity concentration is selected as the solid impurity concentration of the natural gas pipeline for energy substitution, thereby obtaining the solid impurity flow rate of the natural gas pipeline.

5. The method for obtaining pretreatment parameters for hydrogen pipeline erosion analysis as described in claim 4, characterized in that, In step S3, the specific steps for calculating the maximum mass flow rate of solid impurities based on the throughput and velocity of the natural gas pipeline and the energy-equivalent hydrogen pipeline are as follows: The solid impurity flow rate of the natural gas pipeline is compared with the maximum solid impurity carrying capacity of the natural gas pipeline to obtain the solid impurity carrying ratio. When the solid impurity carrying ratio is less than the first preset threshold, the solid impurity flow rate of the natural gas pipeline before replacement is used as the solid impurity flow rate of the hydrogen pipeline. When the solid impurity carrying ratio is greater than the first preset threshold, the solid impurity flow rate of the hydrogen pipeline is calculated based on the maximum solid carrying capacity of the hydrogen pipeline.

6. The method for obtaining preprocessing parameters for hydrogen pipeline erosion analysis as described in claim 5, characterized in that, In step S3, the method for obtaining the maximum solid impurity carrying capacity of the natural gas pipeline includes: A model for the maximum solid impurity carrying capacity in natural gas pipelines is established using the Rizk solids carryover prediction method. The maximum solid impurity carrying capacity of a natural gas pipeline at the corresponding flow velocity and density is calculated based on the model of maximum solid impurity carrying capacity of the natural gas pipeline.

7. The method for obtaining preprocessing parameters for hydrogen pipeline erosion analysis as described in claim 4, characterized in that, The method further includes: Before testing the sampled gas, it is filtered through a filter screen; the mass of impurities carried by the gas is obtained by weighing the filtered solid.

8. The method for obtaining preprocessing parameters for hydrogen pipeline erosion analysis as described in claim 1, characterized in that, In step S1, the parameters of the natural gas pipeline to be replaced are obtained to establish a flow velocity calculation model for the hydrogen pipeline. The specific steps are as follows: S11. Obtain the following parameter: the inner diameter D of the natural gas pipeline of the energy substitution target. N Natural gas pipeline transport capacity Q, the energy substitution target N The minimum operating pressure P of the natural gas pipeline used for energy substitution N Minimum operating pressure P of hydrogen pipeline after energy substitution H Calorific value (H) per unit volume of natural gas and hydrogen N and H H ; S12. After obtaining the above parameters, calculate the standard volumetric hydrogen pipeline transport capacity Q after energy substitution. H : In the formula, Q N This refers to the volumetric transport capacity of natural gas pipelines, in meters (m). 3 / d;Q H This refers to the volumetric flow rate of hydrogen in the pipeline, in meters (m). 3 / d;H N This refers to the calorific value of natural gas per unit volume, expressed in kJ / m³. 3 H H This is the calorific value per unit volume of hydrogen, expressed in kJ / m³. 3 ; S13. The simplified formula for calculating the maximum operating flow velocity of a natural gas pipeline is: In the formula, P N The minimum operating pressure for natural gas pipelines, expressed in barg; D N The inner diameter of the natural gas pipeline is in mm; v N The maximum flow velocity in the natural gas pipeline is expressed in m / s. S14. Calculate the hydrogen pipeline flow rate after energy substitution: In the formula, P H This is the minimum operating pressure for hydrogen pipelines, expressed in barg; v H The maximum flow velocity of hydrogen in the pipeline after energy substitution is expressed in m / s. Therefore, by utilizing the basic information of the pipeline before and after energy substitution, natural gas pipeline data, and the calorific value and physical properties of natural gas and hydrogen, the volumetric throughput of the hydrogen pipeline based on energy equivalent substitution can be calculated, and a formula for calculating the flow velocity of the hydrogen pipeline based on the minimum operating pressure of the hydrogen pipeline can be further established.

9. The method for obtaining preprocessing parameters for hydrogen pipeline erosion analysis as described in claim 8, characterized in that, In step S2, an online multi-point sampling device is set up on the natural gas pipeline to draw natural gas from different positions on the pipeline cross-section to the testing system. The gas at each point is discharged after gas volume measurement and filtration. The following data is recorded and tested: (1) The total volume Q of the sampled and filtered gas. n,x , represents the total volumetric flow rate of the gas sampled at sampling point n during the xth sampling process; (2) the mass of the filtered solid is obtained by weighing, and is denoted as M. n,x , representing the total mass of impurities filtered by sampling point n during the xth sampling process; Therefore, the average solid impurity volume content at the nth sampling point can be calculated and denoted as m. n : In the formula, M n,x Q represents the mass of solids filtered during the x-th filtration at sampling point n in a natural gas pipeline, in kg. n,x The volume of natural gas introduced into the pipeline during the x-th filtration process at sampling point n, in cubic meters (m³). 3 M n The average solid impurity concentration at sampling point n in the natural gas pipeline, in kg / m³. 3 ; The average solid impurity concentrations at different sampling points n were ranked, and the highest average solid impurity concentration was selected as the solid impurity concentration m of the natural gas pipeline for energy substitution. A Therefore, the solid impurity flow rate q of the natural gas pipeline can be obtained. N ; q N =Q N ×m A ; (5) In the formula, m A The concentration of solid impurities in natural gas pipelines used as energy substitutes, in kg / m³. 3 ;q N The flow rate of solid impurities in natural gas pipelines used as an energy substitute is expressed in kg / s.

10. The method for obtaining preprocessing parameters for hydrogen pipeline erosion analysis as described in claim 9, characterized in that, In step S3, to calculate the maximum carrying capacity of solid impurities based on the target natural gas pipeline and the energy-equivalent hydrogen pipeline's throughput and flow rate, and to obtain the energy-equivalent hydrogen pipeline's solid impurity flow rate, the specific method is as follows: S31. Using the Rizk solids carryover prediction method, establish a model for the maximum solids carryover capacity of natural gas pipelines: In the formula, W N The maximum solid impurity carrying capacity of a natural gas pipeline is expressed in kg / s; A is the cross-sectional area of ​​the pipeline, in m². 2 ;v N ρ is the flow velocity of natural gas in m / s. N The density of the medium under operating conditions of a natural gas pipeline, in kg / m³. 3 ; dp is the particle size of the solid particles, in meters (m). S32. The flow rate q of solid impurities in the natural gas pipeline obtained in step S2. N W with the maximum solid impurity carrying capacity of natural gas pipelines N The solid impurity carrying ratio R was obtained by comparison. N : In the formula, R N The solid impurity carry-over ratio of natural gas pipelines, in %; When the solid impurity carrying ratio R N When it is less than 50%, it indicates that all solid impurities in the original natural gas pipeline can be completely carried by the gas. It is assumed that the flow rate of solid impurities transported by the hydrogen pipeline is the same as the flow rate of solid impurities in the natural gas pipeline before energy substitution, and the flow rate of solid impurities transported by the hydrogen pipeline is obtained. When the solid impurity carrying ratio R N When the solid impurities in the original natural gas pipeline exceed 50%, it indicates that there is a risk that the solid impurities in the original natural gas pipeline cannot be completely carried away. Therefore, the solid impurity flow rate transported by the hydrogen pipeline may be higher than the solid impurity flow rate of the natural gas pipeline before energy substitution. Therefore, the solid impurity flow rate of the hydrogen pipeline after energy substitution is further calculated by using the maximum solid carrying capacity of the hydrogen pipeline. S33. Since the presence of solid impurities in hydrogen pipelines is lower than that in natural gas pipelines, a solid impurity flow rate correction factor S is introduced to correct the solid impurity flow rate in hydrogen pipelines, as follows: In the formula, W H The amount of solid impurities carried by the hydrogen pipeline, in kg / s; v H The velocity of hydrogen gas in the pipeline is expressed in m / s. ρ H The density of the medium under operating conditions of the hydrogen pipeline, in kg / m³ 3 ; S is the correction factor for the flow rate of solid impurities in the hydrogen pipeline; This yielded the flow rate of solid impurities in the hydrogen pipeline, providing crucial input parameter preprocessing for subsequent pipeline erosion calculations.

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