Hydrogen-doped natural gas metering method, system, storage medium and electronic device

Abstract

The present application relates to natural gas metering technical field, disclose a kind of hydrogen-doped natural gas metering method, system, storage medium and electronic equipment.Method comprising: obtaining hydrogen-doped natural gas sample from hydrogen-doped natural gas to be metered;Determine the composition and calorific value of hydrogen-doped natural gas sample;Based on the composition and calorific value, determine the analysis metering standard suitable for hydrogen-doped natural gas to be metered;Based on the analysis metering standard, the volume of hydrogen-doped natural gas to be metered is metered.The present application first obtains the composition and calorific value of hydrogen-doped natural gas, then determines the matching analysis metering standard according to the composition and calorific value of hydrogen-doped natural gas, and then under the selected analysis metering standard, the volume of hydrogen-doped natural gas is metered, to ensure accurate and efficient hydrogen-doped natural gas metering.

Description

Technical Field

[0001] This invention relates to the field of natural gas metering technology, and in particular to a method, system, storage medium, and electronic device for metering hydrogen-blended natural gas. Background Technology

[0002] Currently, water electrolysis to produce hydrogen is a highly efficient and clean technology, producing hydrogen with a purity of up to 99%. The energy conversion efficiency from electricity to hydrogen reaches 60%-80%, and the residual heat can be recovered while the hydrogen is being used for combustion. Compared to traditional fossil fuels, hydrogen combustion produces almost no carbon emissions, making it a very clean and environmentally friendly energy source. Therefore, developing the electricity-to-hydrogen conversion method is more in line with the future world's requirements for clean and environmentally friendly energy.

[0003] Currently, most gas appliances use natural gas or liquefied petroleum gas (LPG), so hydrogen cannot be used directly as fuel. However, the development of natural gas pipeline networks is relatively mature, allowing hydrogen to be blended into them for utilization. The current natural gas pipeline network has a very large transport capacity; converting excess electricity into hydrogen and blending it into the natural gas network would not result in resource waste. In 2018, global natural gas demand reached 3.9 trillion cubic meters, of which blending in 3% hydrogen could drive the consumption of 12 million tons of hydrogen. This would help alleviate natural gas supply pressure, promote the large-scale consumption of hydrogen energy, and contribute to building a clean and environmentally friendly energy structure. Therefore, blending natural gas with hydrogen is an important way to effectively transport and utilize hydrogen.

[0004] However, hydrogen and natural gas differ significantly in their physical properties, including density, calorific value, diffusion characteristics, and combustion characteristics, rendering traditional natural gas metering methods unsuitable for measuring hydrogen-blended natural gas. Currently, the metering of hydrogen-blended natural gas remains in its infancy, lacking a well-established and effective system. Therefore, considering the future development trend of hydrogen-blended natural gas, achieving efficient metering of it has become a pressing technical challenge. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method, system, storage medium and electronic device for metering hydrogen-blended natural gas, which addresses the problems existing in the prior art.

[0006] In a first aspect, the present invention provides a method for metering hydrogen-blended natural gas, comprising:

[0007] Obtain hydrogen-blended natural gas samples from the natural gas to be measured;

[0008] Determine the composition and calorific value of the hydrogen-blended natural gas sample;

[0009] The applicable analytical measurement standard for the hydrogen-blended natural gas to be measured is determined based on its composition and calorific value.

[0010] The volume of hydrogen-blended natural gas to be measured is based on analytical metrology standards.

[0011] Secondly, the present invention provides a hydrogen-blended natural gas metering system for implementing the hydrogen-blended natural gas metering method provided by the above-mentioned technical solution, the system comprising:

[0012] The sample acquisition module is used to acquire hydrogen-blended natural gas samples from the hydrogen-blended natural gas to be metered.

[0013] The energy determination module is used to determine the composition and calorific value of hydrogen-doped natural gas samples.

[0014] The standard screening module is used to determine the applicable analytical measurement standards for the hydrogen-blended natural gas to be measured based on its composition and calorific value.

[0015] The metering module is used to measure the volume of hydrogen-blended natural gas to be measured based on analytical metering standards.

[0016] Thirdly, the present invention provides a computer-readable storage medium including instructions that, when executed on a computer, cause the computer to perform the hydrogen-blended natural gas metering method provided by the above-described technical solution.

[0017] Fourthly, the present invention provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the hydrogen-blended natural gas metering method provided by the above technical solution.

[0018] Fifthly, this application also provides a computer program product including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the hydrogen-blended natural gas metering method provided in the above-described scheme.

[0019] The beneficial effects of this invention are as follows: Natural gas is compressible, and its volume can change with pressure and temperature. Therefore, volume measurement must specify the pressure and temperature conditions at the time of measurement, i.e., the so-called analytical measurement standard. This invention first obtains the composition and calorific value of hydrogen-blended natural gas, then determines a matching analytical measurement standard based on the composition and calorific value of the hydrogen-blended natural gas, and then measures the volume of hydrogen-blended natural gas under the selected analytical measurement standard, ensuring accurate and efficient measurement of hydrogen-blended natural gas.

[0020] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] Figure 1 A flowchart illustrating a hydrogen-blended natural gas metering method as an exemplary embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the hydrogen-blended natural gas transportation system provided in an embodiment of the present invention;

[0023] Figure 3 A flowchart for calculating gas volume under standard reference conditions provided in this embodiment of the invention;

[0024] Figure 4 This is a block diagram of a hydrogen-blended natural gas metering system illustrated in an exemplary embodiment of this application. Detailed Implementation

[0025] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0026] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0027] The solutions provided in this invention can be executed by any electronic device, such as a terminal device, or by a terminal device and a server. The server can be a standalone server, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms. No restrictions are imposed here.

[0028] Figure 1 This is a flowchart illustrating a hydrogen-blended natural gas metering method as an exemplary embodiment of this application. Figure 1 As shown, in an exemplary embodiment, the hydrogen-blended natural gas metering may include steps S101 to S104, which are described in detail below:

[0029] S101, Obtain a hydrogen-blended natural gas sample from the hydrogen-blended natural gas to be measured;

[0030] S102, determine the composition and calorific value of the hydrogen-doped natural gas sample;

[0031] S103, Determine the applicable analytical measurement standard for the hydrogen-blended natural gas to be measured based on its composition and calorific value;

[0032] S104, volumetric measurement of the hydrogen-blended natural gas to be measured based on analytical measurement standards.

[0033] Natural gas is compressible, and its volume changes with pressure and temperature. Therefore, volumetric measurement must specify the pressure and temperature conditions at the time of measurement, i.e., the so-called analytical measurement standard. When measuring the volume of hydrogen-blended natural gas, it is necessary to convert the volume of hydrogen-blended natural gas measured under reference conditions to the volume under standard conditions. This conversion process depends on pressure, temperature, and compressibility factor, which is related to both temperature and pressure.

[0034] Therefore, in this embodiment of the invention, the composition and calorific value of hydrogen-blended natural gas are first obtained, and then a matching analytical measurement standard is determined based on the composition and calorific value of the hydrogen-blended natural gas. The volume of the hydrogen-blended natural gas is then measured under the selected analytical measurement standard to ensure accurate and efficient measurement of the hydrogen-blended natural gas.

[0035] Due to the differences in physical properties between hydrogen and natural gas in terms of density, calorific value, diffusion characteristics, and combustion characteristics, hydrogen blending technology for natural gas pipelines mainly brings two challenges: (1) risks to material compatibility and pipeline integrity in terms of pipeline network; (2) impacts on fuel interchangeability and safety in terms of terminal burners.

[0036] After hydrogen molecules are adsorbed on the surface of steel, they easily decompose into hydrogen atoms. Hydrogen atoms have extremely small atomic radii, making them highly susceptible to diffusion as interstitial atoms within the metal crystal lattice. These diffused hydrogen atoms tend to accumulate at defects and stress concentration points, initiating cracks or hydrogen blistering, leading to pipe failure. Hydrogen embrittlement is typically influenced by the coupled effects of material properties, environment, and stress. When pipeline steel is tensile in hydrogen-blended natural gas, the mechanical property loss in notched specimens is significantly higher than in smooth specimens. This indicates that when defects or cracks exist in the pipeline steel, the addition of hydrogen to natural gas causes rapid crack propagation, ultimately leading to pipe failure and potentially resulting in gas leaks and an explosion risk.

[0037] Interchangeability of fuel gases refers to the property that different types or sources of fuel gases can be used interchangeably under the same combustion equipment and application conditions. In short, if two fuel gases have similar calorific values ​​and combustion characteristics, they can be considered interchangeable.

[0038] When considering the interchangeability of fuel gases, key factors include calorific value, combustion rate, density, and the presence of impurities and toxic components. Calorific value, the heat released during combustion, directly affects the thermal efficiency of combustion equipment. Combustion rate determines the stability of combustion within the burner; excessively fast or slow combustion rates can lead to incomplete combustion or an unstable flame. The density of the fuel gas affects its transport and storage methods. Furthermore, impurities and toxic components in the fuel gas can impact the operation of combustion equipment and the health of users.

[0039] Based on the average higher heating value of natural gas of 37.8 MJ / m3, when the hydrogen blending ratio is controlled within 23%, the gas quality meets the measurement standard of 12T reference gas in GB / T13611—2018 "Classification and Basic Characteristics of Urban Gas".

[0040] my country's current standard GB / T37124—2018, "Gas Quality Requirements for Natural Gas Entering Long-Distance Pipelines," stipulates that the maximum hydrogen content in natural gas is 3%. For hydrogen-blended transportation, urban gas pipelines, with minor modifications, can safely and feasiblely achieve a hydrogen volume ratio of ≤10%. The main limitation on hydrogen blending ratios in long-distance pipelines is the adaptability of high-grade steel pipes under high pressure.

[0041] The physicochemical properties of hydrogen and methane, the main component of natural gas, are shown in Table 1. The density, lower heating value, and higher heating value in Table 1 are all values ​​at 20°C and standard atmospheric pressure.

[0042] Table 1

[0043] nature methane hydrogen relative molecular mass 16.04 2.02 Critical temperature (K) 190.65 33.2 Critical pressure (MPa) 4.540 1.315 <![CDATA[Density (kg / m -3 )]]> 0.714 0.089 <![CDATA[Low calorific value (MJ / m -3 )]]> 35.82 10.80 <![CDATA[High calorific value (MJ / m -3 )]]> 37.77 12.09 Flame constant 0.67 0.60 Explosion limits (%) 5.7～14.0 18.2～58.6 <![CDATA[Theoretical air requirement (m 3 ·m -3 )]]> 9.524 2.381 <![CDATA[Diffusion coefficient to air (m 2 ·s -1 )]]> 1.6x10-5 6.1x10-5

[0044] The theoretical air volume required per unit calorific value and the theoretical flue gas volume generated per unit calorific value decrease significantly when the hydrogen volume percentage is between 75% and 80%.

[0045] Theoretically, the volume percentage of hydrogen blended into natural gas is relatively stable (gradually decreasing) when it is below 70%. However, based on the feasibility analysis of using natural gas pipelines to transport hydrogen blends, the high permeability of hydrogen and the presence of hydrogen embrittlement place particularly high demands on the pipe materials and their treatment. From the end-user's perspective, to ensure the normal operation of existing equipment, the volume fraction of hydrogen in the blended natural gas should be controlled below 23%.

[0046] Optionally, embodiments of the present invention can determine the composition of hydrogen-blended natural gas samples using offline or online analysis methods. Offline analysis can be offline gas chromatography; online analysis can be online gas chromatography or external standard method. Online gas chromatography uses argon as the carrier gas and hydrogen as the target gas, employing an offline gas chromatograph to perform gas chromatography analysis to obtain the composition of the hydrogen-blended natural gas sample.

[0047] Offline gas chromatography (GC) analysis is performed in the laboratory by periodically spotting samples and using an offline GC instrument. GC is a column chromatography separation technique that uses gas as the mobile phase and employs a rinsing method. Its main separation principle is based on the different adsorption forces of the components in the sample within the chromatographic column; that is, it utilizes the different partition coefficients of the components between the gas phase and the stationary phase to achieve sample separation.

[0048] Online gas chromatography analysis refers to the automatic sampling of natural gas at specified time intervals using online autosamplers, online gas chromatographs, and other instruments and equipment, and the calculation of natural gas data by analyzing the components.

[0049] Gas chromatography (GC) is based on the partitioning behavior of compounds between the gas and liquid phases, achieving analysis through a series of complex physical and chemical processes. Its basic steps include sample injection, separation, detection, and data processing. First, the sample is injected into the separation column of the gas chromatograph. Inside the column, the compounds are vaporized at high temperatures and then interact with the liquid or solid immobilized within the column. This step is essentially a separation process, as different compounds move at different rates within the column based on their chemical properties and affinities. This allows the different components to be gradually separated and unfolded on the column. Second, the separated compounds enter the detector. The detector is one of the core components of gas chromatography, typically using highly sensitive instruments such as flame ionization detectors (FID) or mass spectrometers. In the detector, the compounds are excited and produce specific signals, which are correlated with the type and concentration of the compounds. By recording and analyzing these signals, the individual components in the separation column can be qualitatively and quantitatively analyzed.

[0050] Gas chromatography is a highly efficient separation technique that separates components in a sample by utilizing the differences in their partition coefficients (or adsorption coefficients) between the stationary and mobile phases. The separated components are then introduced into a detector sequentially, and qualitative analysis is performed based on the response time, while quantitative analysis is performed based on the magnitude of the response value.

[0051] In this embodiment of the invention, the chromatography data processing device can be an Agilent chromatography workstation. The Agilent chromatography workstation can automatically acquire chromatographic data, permanently store it, and perform a wide range of post-processing operations.

[0052] External standard methods, due to the use of standard gases, offer high accuracy, good traceability, and increased comparability and reliability of data between different laboratories. Since natural gas is sold as a commodity, the determination of its calorific value must be accurate, reliable, and traceable, with comparable and reliable component values ​​measured at different locations. Therefore, in natural gas energy measurement, the external standard method will inevitably become the preferred choice for quantitative analysis of natural gas components.

[0053] The embodiments of the present invention can employ a variety of online or offline analytical methods to determine the composition of hydrogen-blended natural gas samples, thereby providing data support for the accurate measurement of hydrogen-blended natural gas samples.

[0054] When measuring calorific value, embodiments of the present invention employ online calorific value measurement procedures within a local metering station, offline calorific value measurement procedures within a local metering station, and remote calorific value measurement procedures, respectively.

[0055] The process of offline measurement of calorific value at the local metering station is adopted, which involves periodically sampling natural gas at the station and then obtaining the calorific value through offline analysis.

[0056] When measuring calorific value, it is essential to obtain a representative mixed sample of natural gas and hydrogen. Since natural gas flows continuously in pipelines, the sampling process is affected by various factors, such as the location of sampling points, the sampling procedure, fluctuations in gas composition, and the effectiveness of the measurement system.

[0057] Therefore, when sampling pipeline natural gas, the relevant provisions in the "Natural Gas Sampling Guidelines" (GB / T13609—2017) must be strictly followed. Sampling can be divided into continuous direct sampling, fixed-point and fixed-period sampling, and incremental sampling. The natural gas samples can be analyzed online at the local metering station or sent to a different location for offline analysis. Here, the periodic fixed-point sampling method is adopted.

[0058] Calorific value determination is a core step in natural gas energy measurement. The direct method, which uses a specialized calorimeter to measure the actual heat released after a certain amount of natural gas is fully combusted under specified conditions, is the most scientific and accurate method for determining calorific value and is suitable for various applications. Figure 2 Interfaces 1 to 3 and interface 5 are shown in the schematic diagram of the hydrogen-blended natural gas transportation system.

[0059] The basic principle of the indirect method is to analyze the combustible components and mole fractions in natural gas using gas chromatography, and then calculate the actual calorific value of the natural gas by weighted averaging based on the calorific value of each pure substance. This method is relatively simple to implement and easy to automate, therefore it is currently the most widely used. However, it is easily affected by the water vapor content in the natural gas. This method is suitable for... Figure 2 Interfaces 1 to 3 and interface 5 are shown in the schematic diagram of the hydrogen-blended natural gas transportation system.

[0060] The correlation method characterizes the calorific value of natural gas by measuring several physicochemical parameters related to its calorific value. For distribution stations equipped with analytical instruments such as gas chromatographs, hydrogen sulfide analyzers, and water / hydrocarbon dew point analyzers, indirect methods can be used to determine the calorific value of natural gas.

[0061] Optionally, in embodiments of the present invention, a calorimeter can be used to measure the actual heat released after a pre-measured hydrogen-blended natural gas sample is fully combusted under specified conditions, and this heat can be used as the calorific value of the hydrogen-blended natural gas sample.

[0062] Optionally, embodiments of the present invention may further determine the combustible components and mole fractions in the composition of the hydrogen-blended natural gas sample; determine the calorific value of each combustible component; and calculate the calorific value of the hydrogen-blended natural gas sample by weighted averaging based on the mole fractions.

[0063] Optionally, embodiments of the present invention determine the applicable analytical metrology standard for the hydrogen-blended natural gas to be measured based on its composition and calorific value, including: determining the hydrogen concentration range of the hydrogen-blended natural gas to be measured according to its composition; and determining the matching analytical metrology standard according to the hydrogen concentration range, calorific value, and a pre-established matching relationship; wherein, the matching relationship characterizes the correspondence between the hydrogen concentration range and calorific value of the hydrogen-blended natural gas and the analytical metrology standard. The matching relationship in embodiments of the present invention can be shown in Table 2.

[0064] Table 2

[0065]

[0066]

[0067] Table 2 shows the statistical overview of the applicable ranges for hydrogen concentration, relative density, and higher calorific value in natural gas according to current standards for some natural gas products and analytical measurement. GB17820—2018 specifies the minimum requirements for the higher calorific value of different types of natural gas. Taking three typical natural gas types as examples, to meet the requirements for the higher calorific value of Class I gas, the hydrogen concentration in the natural gas must not exceed 14%, 12%, and 24%, respectively. When the actual higher calorific value of natural gas is lower, the allowable hydrogen concentration will be even lower.

[0068] For natural gas composition analysis standards such as GB / T13610—2020, GB / T17281—2016, GB / T27894.3—2011, and GB / T27894.6—2012, the maximum applicable hydrogen concentration range is 10%. When the hydrogen blending concentration is higher than the hydrogen concentration range recommended by the standard method, it is necessary to confirm whether the method is applicable to the analysis and testing of natural gas with higher hydrogen blending concentrations.

[0069] GB / T11062—2020 is applicable to the calculation of gas physical properties parameters with a reference compressibility factor greater than 0.9. It is applicable when the hydrogen blending concentration of natural gas is between 0% and 100%. The applicable hydrogen concentration range of GB / T17747 series standards is 0% to 10%, and it also specifies the range of relative density and higher heating value. For natural gas with a hydrogen blending concentration of more than 10% but less than 40%, the relevant physical properties parameters, such as compressibility factor and velocity of sound, can be calculated using GB / T30491.2—0XX (equivalent to ISO20765-2:2015), which is currently under development.

[0070] The applicable range for the relative density of natural gas defined by standard methods for different types of natural gas flow meters is 0.55–0.80. However, when the hydrogen concentration of some natural gas exceeds 3%, the relative density is less than 0.55. Targeted experimental testing is needed to verify whether currently used natural gas flow meters are suitable for the accurate measurement of hydrogen-blended natural gas with a lower relative density, and to revise the applicable range specified in the relevant standard methods.

[0071] Argon has a significantly different thermal conductivity compared to hydrogen and helium (as shown in Table 3 below). Therefore, this invention adds an additional separation and detection process using Ar as the carrier gas to the currently used gas chromatograph to achieve the analysis of hydrogen concentration in hydrogen-blended natural gas.

[0072] Table 3

[0073]

[0074] The recommended method for calculating sound velocity in GB / T30500—2014 is AGA Report No. 10 (equivalent to the calculation method in GB / T30491.1), and it specifies that the allowable deviation between the calculated sound velocity and the sound velocity measured by the ultrasonic flowmeter is 0.2%. The comparative analysis in Section 1.2 shows that when the hydrogen concentration in natural gas is higher than 10%, there is a deviation of approximately 0.2% between the calculation results of GB / T30491.1—2014 and ISO20765-2:2015. Since the latter has a wider applicability to hydrogen-blended natural gas, it is recommended that the method recommended by the ISO standard be adopted for the calculation of sound velocity verification in ultrasonic flowmeters. Meanwhile, the compressibility factor calculation method GB / T17747.2—2011 recommended by JJG1003—2016 is applicable to hydrogen concentrations less than 10%. It is recommended to use ISO20765-2:2015 for compressibility factor calculations when the hydrogen concentration is greater than 10%.

[0075] Optionally, embodiments of the present invention perform volumetric measurement of the hydrogen-blended natural gas to be measured based on analytical metrology standards, including: determining the compressibility coefficient calculated under analytical metrology standards; and converting the volumetric measurement of the hydrogen-blended natural gas obtained under reference conditions into the volumetric measurement under standard conditions based on the compressibility coefficient.

[0076] A natural gas volumetric flow metering system consists of one or more metering loops. Typically, the flow meter measures the gas volume under actual operating conditions. The natural gas volume measurement device consists of a metering standard device, usually a turbine flow meter or ultrasonic flow meter, plus temperature transmitters and pressure transmitters, etc., which converts the volume of natural gas flowing through the cross-section of the pipeline per unit time into a volume measurement value under standard conditions.

[0077] Natural gas is compressible, and its volume changes with pressure and temperature. Therefore, volumetric measurements must specify the pressure and temperature conditions under which the measurement was performed, i.e., standard conditions. Converting the volume of natural gas measured under reference conditions to its volume under standard conditions is based on gas pressure, temperature, and compressibility factor. The procedure for calculating the gas volume under standard reference conditions is as follows: Figure 3 As shown.

[0078] Calculate the volume V under the standard reference conditions based on the volume V under the reference conditions. n for:

[0079] V n =V·z

[0080] Where V is the volume under the reference condition; z is the compressibility coefficient (i.e., ... Figure 3 (z factor in the text).

[0081] The compressibility factor z can be calculated using the following formula:

[0082]

[0083] In the formula: T n The standard reference temperature is T; the reference temperature is P. amb P is the average atmospheric pressure at the metering instrument; P is the reference pressure; P H2O P is the partial pressure of water in natural gas. n Z represents the standard pressure; Z is the compressibility factor under reference conditions; Z n This is the compression factor under standard reference conditions.

[0084] A key quantity to calculate during volume conversion is the compressibility factor of natural gas under reference conditions. For the calculation of standard cubic meters of a mixture like natural gas, the first step is to calculate the compressibility factor Z under operating conditions.

[0085] Using the calculation method in GB / T 17747.2-1999, the compressibility factor of natural gas can be calculated based on its detailed mole fraction composition and related pressure and temperature. This calculation method, also known as the AGA8-92DC method, is mainly applied to pipeline gas transmission within the pressure P and temperature T range during normal gas transmission and distribution, with a calculation uncertainty of approximately 0.1%.

[0086] The embodiments of this invention clearly demonstrate the significant impact of hydrogen blending on the physical properties of natural gas. Compared to unblended natural gas, conventional pipeline natural gas with a hydrogen concentration of 40% exhibits a decrease in higher heating value, relative density, Wobbe index, and viscosity of approximately 27%, 35%, 10%, and 20%, respectively. Under conditions of 10 MPa and 20°C, the compressibility factor and velocity of sound of conventional natural gas increase by 18% and 34%, respectively. For every 1% increase in hydrogen concentration, the volumetric energy density of the hydrogen-blended natural gas decreases by approximately 1%.

[0087] This invention addresses the problem that most online gas chromatographs used in current natural gas metering stations cannot detect hydrogen. It proposes to add an additional separation gas path to detect the hydrogen concentration in hydrogen-blended natural gas, ensuring accurate analysis of high-concentration hydrogen-blended natural gas.

[0088] For the calculation of compressibility factor and velocity of sound of hydrogen-blended natural gas, ISO 20765-2:2015 is recommended as the standard calculation method for flow totalizers.

[0089] Figure 4 This is a block diagram of a hydrogen-blended natural gas metering system illustrated in an exemplary embodiment of this application. Figure 4 As shown, the hydrogen-blended natural gas metering system is used to implement the hydrogen-blended natural gas metering method provided in any of the above embodiments. The system includes a sample acquisition module, an energy determination module, a standard screening module, and a metering module.

[0090] The sample acquisition module is used to acquire hydrogen-blended natural gas samples from the hydrogen-blended natural gas to be measured; the energy determination module is used to determine the composition and calorific value of the hydrogen-blended natural gas sample; the standard screening module is used to determine the applicable analytical metrology standards for the hydrogen-blended natural gas to be measured based on the composition and calorific value; and the metrology module is used to perform volumetric metrology of the hydrogen-blended natural gas to be measured based on the analytical metrology standards.

[0091] This invention also provides a computer-readable storage medium including instructions that, when executed on a computer, cause the computer to perform the hydrogen-blended natural gas metering method provided in any of the above embodiments.

[0092] This invention also provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the hydrogen-blended natural gas metering method provided in any of the above embodiments.

[0093] This invention also provides a computer program product including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the hydrogen-blended natural gas metering method provided in the various optional embodiments described above.

[0094] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described apparatus and unit can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0095] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0096] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention, depending on actual needs.

[0097] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0098] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for metering hydrogen-blended natural gas, characterized in that, include: Obtain hydrogen-blended natural gas samples from the natural gas to be measured; Determine the composition and calorific value of the hydrogen-doped natural gas sample; The applicable analytical measurement standard for the hydrogen-blended natural gas to be measured is determined based on the composition and calorific value of the components. The determination of the applicable analytical measurement standard for the hydrogen-blended natural gas to be measured based on the component composition and calorific value includes: The hydrogen concentration range of the hydrogen-blended natural gas to be measured is determined based on the composition of the components. The matching analytical measurement standard is determined based on the hydrogen concentration range, the calorific value, and the pre-established matching relationship; The matching relationship characterizes the correspondence between the hydrogen concentration range and calorific value of hydrogen-blended natural gas and the analytical measurement standard. The volume of the hydrogen-blended natural gas to be measured is determined based on the aforementioned analytical measurement standards. The volumetric measurement of the hydrogen-blended natural gas to be measured based on the analytical measurement standard includes: Determine the compressibility coefficient calculated under the aforementioned analytical measurement standard; Based on the aforementioned compressibility coefficient, the metered volume of hydrogen-blended natural gas obtained under reference conditions is converted into the metered volume under standard conditions.

2. The method according to claim 1, characterized in that, Determining the composition of the hydrogen-blended natural gas sample includes: determining the composition of the hydrogen-blended natural gas sample based on offline analysis or online analysis.

3. The method according to claim 2, characterized in that, The offline analysis method is offline gas chromatography analysis, and the online analysis method is online gas chromatography analysis or external standard method; The online gas chromatography method uses argon as the carrier gas and hydrogen as the target gas, and performs gas chromatography analysis using an offline gas chromatograph to obtain the component composition of the hydrogen-blended natural gas sample.

4. The method according to claim 1, characterized in that, Determining the calorific value of the hydrogen-blended natural gas sample includes: measuring the actual heat released after the hydrogen-blended natural gas sample is fully combusted under specified conditions using a calorimeter, and using this heat as the calorific value of the hydrogen-blended natural gas sample.

5. The method according to claim 1, characterized in that, Determining the calorific value of the hydrogen-doped natural gas sample includes: Determine the combustible components and their mole fractions in the composition of the hydrogen-doped natural gas sample; The calorific value of each combustible component is determined, and the calorific value of the hydrogen-blended natural gas sample is calculated by weighted averaging based on the mole fraction.

6. A hydrogen-blended natural gas metering system, characterized in that, The system for implementing the hydrogen-blended natural gas metering method according to any one of claims 1 to 5 comprises: The sample acquisition module is used to acquire hydrogen-blended natural gas samples from the hydrogen-blended natural gas to be metered. An energy determination module is used to determine the composition and calorific value of the hydrogen-doped natural gas sample. A standard screening module is used to determine the applicable analytical measurement standards for the hydrogen-blended natural gas to be measured based on the component composition and calorific value. The determination of the applicable analytical measurement standard for the hydrogen-blended natural gas to be measured based on the component composition and calorific value includes: The hydrogen concentration range of the hydrogen-blended natural gas to be measured is determined based on the composition of the components. The matching analytical measurement standard is determined based on the hydrogen concentration range, the calorific value, and the pre-established matching relationship; The matching relationship characterizes the correspondence between the hydrogen concentration range and calorific value of hydrogen-blended natural gas and the analytical measurement standard. The metering module is used to measure the volume of the hydrogen-blended natural gas to be measured based on the analytical metering standard. The volumetric measurement of the hydrogen-blended natural gas to be measured based on the analytical measurement standard includes: Determine the compressibility coefficient calculated under the aforementioned analytical measurement standard; Based on the aforementioned compressibility coefficient, the metered volume of hydrogen-blended natural gas obtained under reference conditions is converted into the metered volume under standard conditions.

7. A computer-readable storage medium comprising instructions, characterized in that, When the instructions are executed on a computer, the computer performs the hydrogen-blended natural gas metering method as described in any one of claims 1 to 5.

8. An electronic device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, when the processor executes the program, it implements the hydrogen-blended natural gas metering method as described in any one of claims 1 to 5.

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