A comprehensive analysis method and apparatus for hydrogen-blended combustion characteristics of natural gas pipelines

Abstract

This invention discloses a comprehensive analysis method and apparatus for the combustion characteristics of hydrogen-blended natural gas pipelines, relating to the fields of gas transmission and distribution and comprehensive utilization of hydrogen energy. Addressing the lack of a systematic method in existing technologies for simultaneously predicting the calorific value, Wobbe index, and combustion potential of hydrogen-blended natural gas, this invention constructs an integrated computational model encompassing thermodynamics, interchangeability, and combustion kinetics, employing a modular design: it calculates the higher and lower calorific values ​​of the mixed gas using a weighted average method, calculates the Wobbe index based on relative density and internationally accepted definitions, and innovatively quantifies combustion potential using a semi-empirical model; it also cross-compares with national standards such as GB17820, and uses multi-indicator collaborative decision-making to determine the feasibility of the proposed scheme. This invention overcomes the shortcomings of the three-dimensional comprehensive evaluation of hydrogen-blended natural gas, offering accurate calculations, strong compliance, and the ability to rapidly generate hydrogen blending ratio-combustion characteristic maps, providing technical support for the design of hydrogen-blended transportation projects, operational safety assessments, and the formulation of relevant national standards.

Description

Technical Field

[0001] This invention relates to the fields of gas transmission and distribution, comprehensive utilization of hydrogen energy and combustion engineering technology, specifically to a comprehensive analysis method and apparatus for the combustion characteristics of hydrogen-blended natural gas pipelines. Background Technology

[0002] Against the backdrop of the global green and low-carbon energy transition, utilizing existing natural gas pipeline networks to blend with hydrogen is an effective way to achieve large-scale and economical hydrogen energy transportation. However, hydrogen and natural gas (whose main component is methane) have significantly different physicochemical properties. Blending with hydrogen will systematically change the thermodynamic characteristics and combustion behavior of the mixed gas, posing new challenges to pipeline transportation safety, metering and trading, compatibility with end-use appliances, and the stability of the gas supply system.

[0003] Currently, industry research on hydrogen-blended natural gas focuses on single or partial characteristic indicators: for example, adding hydrogen reduces the density and calorific value of the mixed gas, leading to a decrease in the Wobbe index (the Wobbe index decreases by about 0.1 MJ / m³ for every 1% volume of hydrogen added), and the supercombustion range (such as the allowance of ±5% fluctuation for Class 12T natural gas) can easily cause combustion problems; at the same time, the high reactivity of hydrogen will increase the flame temperature, accelerate the flame propagation speed, and increase the risk of deflagration.

[0004] Existing national standards, such as "Natural Gas" (GB17820) and "General Requirements for Interchangeability of Natural Gas Entering Long-Distance Pipelines" (GB / Z33440-2016), only partially specify basic indicators and interchangeability parameters for natural gas. However, they lack a systematic and comprehensive calculation method for hydrogen-blended natural gas, and cannot simultaneously and accurately predict the three main indicators: calorific value (energy basis), Wobbe index (interchangeability), and combustion potential (safety and stability). A complete calculation and evaluation system has not yet been established. With the advancement of the national standard "Technical Requirements for Hydrogen-Blended Natural Gas Pipeline Transportation," the industry's demand for a unified and standardized method for analyzing the combustion characteristics of hydrogen-blended natural gas is becoming increasingly urgent. Summary of the Invention

[0005] To address this, the present invention provides a comprehensive analysis method and apparatus for the combustion characteristics of hydrogen-blended natural gas pipelines, solving the problems of existing technologies lacking the ability to simultaneously and accurately predict the calorific value, Wobbe index, and combustion potential of hydrogen-blended natural gas, failing to integrate national standards to form a complete three-dimensional calculation and evaluation system, and thus being unable to provide unified and standardized technical support for hydrogen-blended transportation projects.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines, comprising: S1. Input basic data, which includes the composition of natural gas and the volume fraction of each component, the volume fraction of hydrogen blending, and the standard higher calorific value and standard lower calorific value of each pure component under standard conditions. S2. Based on thermodynamic principles, the weighted average method is used to calculate the volumetric higher heating value and volumetric lower heating value of the mixed gas, thus completing the quantification of the basic energy characteristics. S3. Based on the volumetric calorific value of the mixed gas described in step S2, first calculate the relative density of the mixed gas under the standard conditions, and then calculate the Wobbe index of the mixed gas according to the internationally accepted definition of the Wobbe index to achieve the quantification of interchangeability index. S4. Based on the principles of combustion dynamics, a semi-empirical calculation model is constructed that comprehensively considers the high combustion rate of hydrogen and the differentiated contributions of different hydrocarbon gases to flame characteristics. The combustion potential of the mixed gas is calculated through the semi-empirical calculation model to complete the quantification of safety and stability indicators. S5. Establish a national standard cross-comparison mechanism, and verify the compliance of the calorific value, the Wobbe index, and the combustion potential results obtained in steps S2, S3, and S4 against the requirements of national standard documents. S6. Using a multi-indicator collaborative decision-making logic, verify whether the calorific value, the fluctuation range of the Huabai index, and the combustion potential simultaneously meet all the requirements of risk control. If all are met, output a feasible conclusion for the solution; if any indicator exceeds the standard, trigger an early warning and output optimization suggestions.

[0007] As a preferred scheme for the comprehensive analysis method of hydrogen-blended combustion characteristics of natural gas pipelines, the target calorific value of the mixed gas in step S1 is 101.325 kPa and 20℃ under standard conditions.

[0008] As a preferred method for comprehensive analysis of hydrogen-blended combustion characteristics in natural gas pipelines, the calculation formula for the weighted average method in step S2 is as follows:

[0009] In the formula, H mix The target calorific value of the mixed gas is calculated as H when the higher calorific value is calculated. s , mix When calculating the lower heating value, it is H. i , mix The unit is MJ / m³; y i Let be the volume fraction of the i-th gas component in the gas mixture, and let y be the volume fraction of all components. i The sum equals 1; H i The calorific value of the i-th pure gaseous component under the standard conditions is H when calculating the higher calorific value. s , i When calculating the lower heating value, it is H. i , i The unit is MJ / m³; n is the total number of components in the gas mixture.

[0010] As a preferred method for comprehensive analysis of the combustion characteristics of hydrogen-blended natural gas pipelines, the components of the mixed gas are hydrogen (H2), methane (CH4), ethane (C2H6), propane (C3H8), nitrogen (N2), and carbon dioxide (CO2). The calorific value calculation formula is as follows: H mix =y H2 ·H H2 +y CH4 ·H CH4 +y C2H6 ·H C2H6 +……+y N2 ·H N2 +y CO2 ·H CO2 In the formula, y H2 y CH4 y C2H6 y C3H8 y N2 y CO2 These are the volume fractions of each corresponding component, H H2 H CH4 H C2H6 H C3H8 H N2 H CO2 The target calorific value of each corresponding component under the standard conditions. As a preferred method for comprehensive analysis of hydrogen-blended combustion characteristics in natural gas pipelines, the formula for calculating the Huabai index in step S3 is:

[0011] In the formula, H s The volumetric calorific value of the mixed gas calculated in step S2 is expressed in MJ / m³, and s is the relative density of the mixed gas.

[0012] As a preferred method for comprehensive analysis of hydrogen-blended combustion characteristics in natural gas pipelines, the expression of the semi-empirical calculation model in step S4 is: CP = k1·(H2%) + k2·(∑(a) ᵢ ·CnHm%)) In the formula, H2% is the hydrogen gas integral, CnHm% is the volume fraction of various hydrocarbon gases, k1 and k2 are weighting coefficients related to combustion rate, and aᵢ is the characteristic coefficient of different hydrocarbon components. The semi-empirical calculation model simplifies to a linear form as follows: CP=k1·x H2 +b CH4 ·x CH4 +b C2H6·x C2H6 +...+b CnHm ·x CnHm In the formula, x H2 x CH4 x C2H6 ...x CnHm These represent the volume percentages of hydrogen and each hydrocarbon component, respectively.

[0013] As a preferred scheme for the comprehensive analysis method of hydrogen-blended combustion characteristics in natural gas pipelines, coefficients k1, k2, and a ᵢ Determined in the following ways: Based on the reference gas conforming to GB / T13611, multiple mixed gas samples with hydrogen doping ratios of 0%-30% were prepared. The main combustion parameters, such as the laminar flame propagation velocity, of each gas sample were measured to obtain m sets of experimental data. Each set of data includes one measured value of combustion potential and the corresponding gas composition. Based on the m sets of experimental data, a matrix equation Y=Xβ is constructed, where Y is an m×1 column vector of the measured combustion potential values, X is an m×p design matrix, p is the number of independent variables (i.e., the number of combustible component types + 1), and β is a p×1 column vector of the regression coefficients to be determined [k1, b]. CH4 ,b C2H6 ,...] T ; Solve β=(X) using the least squares method T X) -1 X T Y, so that the average relative error between the calculated combustion potential and the experimental value is less than 10%.

[0014] As a preferred method for comprehensive analysis of the combustion characteristics of hydrogen-blended natural gas pipelines, the calorific value, the Wobbe index, and the combustion potential results in step S5 are determined based on the requirements of the standards GB17820 "Natural Gas", GB / Z33440-2016 "General Requirements for Interchangeability of Natural Gas Entering Long-Distance Pipelines", and GB / T13611 "Classification and Basic Characteristics of Urban Gas".

[0015] As a preferred method for comprehensive analysis of the combustion characteristics of hydrogen blending in natural gas pipelines, step S6 further includes plotting a hydrogen blending ratio-combustion characteristic graph to visually reveal the correspondence between the hydrogen blending ratio and the combustion characteristics of the mixed gas.

[0016] This invention also provides a comprehensive analysis device for the hydrogen-blended combustion characteristics of natural gas pipelines, employing the aforementioned comprehensive analysis method for the hydrogen-blended combustion characteristics of natural gas pipelines, comprising: Data input unit: used to input basic data, including the composition of natural gas and the volume fraction of each component, the volume fraction of hydrogen blending, and the standard higher calorific value and standard lower calorific value of each pure component under standard conditions. Calorific value calculation unit: used to calculate the volumetric calorific value and volumetric calorific value of a gas mixture based on thermodynamic principles and using a weighted average method, thereby quantifying the basic energy characteristics; The Warburg Index Calculation Unit is used to calculate the relative density of the mixed gas under standard conditions based on the volumetric calorific value of the mixed gas in the calorific value calculation unit, and then calculate the Warburg Index of the mixed gas according to the internationally accepted definition of the Warburg Index, thereby realizing the quantification of interchangeability indicators. Combustion potential calculation unit: Based on the principles of combustion dynamics, it constructs a semi-empirical calculation model that comprehensively considers the high combustion rate of hydrogen and the differentiated contributions of different hydrocarbon gases to flame characteristics. The combustion potential of the mixed gas is calculated through the semi-empirical calculation model to complete the quantification of safety and stability indicators. National Standard Comparison Unit: Used to establish a national standard cross-comparison mechanism, which verifies the compliance of the calorific value, the Wobbe index, and the combustion potential results obtained by the calorific value calculation unit, the Wobbe index, and the combustion potential calculation unit against the requirements of the national standard documents one by one. Decision result output unit: Used to verify whether the calorific value, the fluctuation range of the Huabai index, and the combustion potential simultaneously meet all the requirements of risk control by adopting multi-indicator collaborative decision judgment logic. If all are met, the feasible conclusion of the scheme is output; if any indicator exceeds the standard, an early warning is triggered and optimization suggestions are output.

[0017] The present invention has the following advantages: This invention constructs an integrated calculation model covering thermodynamics, interchangeability, and combustion dynamics, integrating the calculation and evaluation of three major indicators: calorific value (energy basis), Wobbe index (interchangeability), and combustion potential (safety and stability). This forms a complete analysis system for the combustion characteristics of hydrogen-blended natural gas, overcoming the limitations of existing technologies that can only analyze single or partial indicators, and filling the technical gap in the three-dimensional comprehensive evaluation of hydrogen-blended natural gas.

[0018] The calorific value calculation of this invention adopts the weighted average method, which is strictly derived based on the standard calorific value and volume fraction of each component. The combustion potential model is fitted with experimental data conforming to GB / T13611 reference gas and 0%-30% hydrogen doping ratio. The coefficients are solved by the least squares method, so that the average relative error between the calculated value and the experimental value is less than 10%. Furthermore, it can be optimized and calibrated in combination with experimental data to ensure the accuracy and stability of the prediction of the three major indicators.

[0019] The calculation process and evaluation logic of this invention are closely aligned with current national standards such as "Natural Gas" (GB17820), "General Requirements for Interchangeability of Natural Gas Entering Long-Distance Pipeline Networks" (GB / Z33440-2016), and "Classification and Basic Characteristics of Urban Gas" (GB / T13611). It can also provide technical reference for the "Technical Requirements for Hydrogen-Blended Transmission of Natural Gas Pipelines" which is currently being developed, ensuring that the analysis results comply with industry standards and avoiding operational risks caused by exceeding the limits of the indicators.

[0020] This invention calculates each indicator independently yet collaboratively, with a clear and easy-to-understand process that can quickly process basic data and output results. It provides technical support for the entire process of hydrogen-blended transportation engineering, including design, operation and commissioning, and safety assessment, without the need for complex experimental equipment, and is adaptable to different pipeline systems and end-user scenarios. At the same time, it can generate hydrogen blending ratio-combustion characteristic graphs, providing quantitative data support for determining the maximum safe hydrogen blending ratio that a specific pipeline network and end-user equipment can withstand, and helping to scientifically manage the hydrogen blending boundary.

[0021] This invention employs a multi-indicator collaborative decision-making logic, requiring that the hydrogen blending scheme must simultaneously meet the requirements for calorific value, Wahbe index fluctuation range, and combustion potential risk control. If any indicator exceeds the standard, an early warning is immediately triggered and optimization suggestions are output, completely avoiding the safety hazards caused by single-indicator decision-making and improving the safety of hydrogen-blended natural gas transportation and use. Attached Figure Description

[0022] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0023] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0024] Figure 1 This is a schematic diagram of the comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines provided in an embodiment of the present invention; Figure 2 This is a technical architecture diagram of the comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines provided in this embodiment of the invention; Figure 3This is a schematic diagram of the architecture of the comprehensive analysis device for hydrogen-blended combustion characteristics of natural gas pipelines provided in an embodiment of the present invention. Detailed Implementation

[0025] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0026] See Figure 1 and Figure 2 This invention provides a comprehensive analysis method for the hydrogen-blended combustion characteristics of natural gas pipelines, comprising the following steps: S1. Input basic data, which includes the composition of natural gas and the volume fraction of each component, the volume fraction of hydrogen blending, and the standard higher calorific value and standard lower calorific value of each pure component under standard conditions. Specifically, the composition and volume fraction of natural gas (such as CH4, C2H5, etc.) directly affect the overall composition of the gas mixture, while the volume fraction of hydrogen blending is the main variable (determining the hydrogen blending ratio). The standard higher heating value (the total heat released by the condensation of water vapor after complete combustion) and lower heating value (the heat when water vapor does not condense) of each pure component are the main parameters for calculating the calorific value of the gas mixture. The standard conditions (specifically defined as 101.325 kPa and 20°C) are specified to unify the calculation benchmark, avoid parameter deviations caused by differences in pressure and temperature, and conform to the common calculation specifications in the gas industry.

[0027] S2. Based on thermodynamic principles, the weighted average method is used to calculate the volumetric higher heating value and volumetric lower heating value of the mixed gas, thus completing the quantification of the basic energy characteristics. Specifically, the gross calorific value of a gas mixture is the weighted sum of the calorific values ​​of each component according to its proportion in the mixture. The logic of the weighted average method is that the contribution of each component to the calorific value of the gas mixture is proportional to its volume fraction (in a gas system, volume fraction is equivalent to mole fraction), and this is expressed through y i ·H i The method calculates the calorific value contribution of each individual component and then sums them to obtain the total calorific value, ensuring the scientific accuracy of energy quantification. This method is a classic approach in the gas industry for calculating the calorific value of mixed gases, combining accuracy and simplicity. It can accurately calculate both high and low calorific values ​​simultaneously, providing fundamental energy data for subsequent trade measurement and heat load assessment.

[0028] S3. Based on the volumetric calorific value of the mixed gas described in step S2, first calculate the relative density of the mixed gas under the standard conditions, and then calculate the Wobbe index of the mixed gas according to the internationally accepted definition of the Wobbe index to achieve the quantification of interchangeability index. Specifically, the Wassell Index (WAI) is a key indicator for measuring gas interchangeability. It represents the relationship between the heat released by combustion per unit volume of gas and the flow resistance, directly determining the suitability of end-use appliances (such as stoves and boilers). The calculation logic follows the principle of first calculating density and then the index. Relative density (the ratio of the density of the mixed gas to the density of dry air) reflects the flow characteristics of the mixed gas. Combined with high calorific value, it comprehensively reflects the matching degree of gas supply and heat release in the appliance. (Internationally accepted definition) Its essence is: high calorific value (H s The square root of relative density determines the heat load potential. The ratio of the two values ​​reflects the flow resistance (the greater the density, the greater the flow resistance). It can characterize the stability of the heat load of the appliance after gas replacement and ensure the interchangeability of different gases in the same appliance.

[0029] S4. Based on the principles of combustion dynamics, a semi-empirical calculation model is constructed that comprehensively considers the high combustion rate of hydrogen and the differentiated contributions of different hydrocarbon gases to flame characteristics. The combustion potential of the mixed gas is calculated through the semi-empirical calculation model to complete the quantification of safety and stability indicators. Specifically, the main function of combustion potential is to characterize the intensity of combustion of fuel gas, encompassing combustion rate, flame stability, and flashback tendency, directly related to the operational safety of pipeline networks and appliances. From a combustion kinetics perspective, the high reactivity of hydrogen (fast chain reaction rate) causes its combustion rate to be much higher than that of hydrocarbons such as methane. The differences in molecular structure among different hydrocarbons (CH4, C2H5, C3H8) result in variations in their flame propagation speed, ignition energy, and other characteristics, requiring separate consideration of their contributions. The semi-empirical calculation model is designed based on theoretical guidance and experimental calibration. By introducing weighting coefficients k1 (reflecting the high combustion rate of hydrogen), k2 (reflecting the overall contribution of hydrocarbons), and characteristic coefficient aᵢ (distinguishing the differentiated effects of different hydrocarbons), it balances theoretical logic with actual combustion characteristics. The model is concise and can be calculated quickly, solving the problems of complex pure theoretical models and time-consuming pure experimental methods, thus achieving efficient quantification of safety indicators.

[0030] S5. Establish a national standard cross-comparison mechanism, and verify the compliance of the calorific value, the Wobbe index, and the combustion potential results obtained in steps S2, S3, and S4 against the requirements of national standard documents. Specifically, cross-comparison with national standards ensures that analysis results comply with mandatory or guiding industry standards, mitigating engineering risks. "Natural Gas" (GB17820) is the fundamental quality standard for natural gas products, limiting the calorific value range to guarantee the quality of gas energy supply. "Classification and Basic Characteristics of Urban Gas" (GB / T13611) clarifies the allowable fluctuation range of the Wah Bai Index for different categories of gas (such as 12T category), serving as the primary basis for end-use appliance compatibility. "General Requirements for Interchangeability of Natural Gas Entering Long-Distance Pipelines" (GB / Z33440-2016) focuses on long-distance pipeline scenarios, implicitly requiring combustion stability (such as avoiding violent combustion and backfire). The design logic of the cross-comparison mechanism is comprehensive and thorough, ensuring compliance with standards in all three dimensions: energy, interchangeability, and safety, providing compliance assurance for engineering applications.

[0031] S6. Using a multi-indicator collaborative decision-making logic, verify whether the calorific value, the fluctuation range of the Huabai index, and the combustion potential simultaneously meet all the requirements of risk control. If all are met, output a feasible conclusion for the solution; if any indicator exceeds the standard, trigger an early warning and output optimization suggestions.

[0032] Specifically, the engineering application of hydrogen-blended natural gas must simultaneously meet three major requirements: energy supply, appliance compatibility, and safe operation. Meeting a single indicator cannot guarantee the stability of the overall system. The logic of multi-indicator collaborative decision-making is a veto system; if any indicator (calorific value, Wobbe index, combustion potential) exceeds the main limit, it means that there is an engineering risk (such as insufficient calorific value affecting energy supply, excessive Wobbe index causing appliance failure, and excessive combustion potential causing deflagration). The early warning mechanism is designed to promptly alert to risks, and optimization suggestions (such as adjusting the hydrogen blending ratio and optimizing the natural gas composition) are derived from the reverse reasoning of the indicator exceeding the limit, ensuring the operability of the solution and realizing the logic of calculation, evaluation, and optimization.

[0033] In one possible embodiment, the target calorific value of the mixed gas in step S1 is 101.325 kPa and 20°C under standard conditions.

[0034] Specifically, 101.325 kPa is standard atmospheric pressure (an internationally recognized benchmark pressure), and 20°C is a standard temperature commonly used in the gas industry. This state definition originates from national standards such as "Natural Gas" (GB17820). The purpose of setting standard states is to eliminate the influence of pressure and temperature on parameters such as gas volume, density, and calorific value. The physicochemical properties of gases change significantly with pressure and temperature. Unifying standard states ensures the comparability of calculation results under different scenarios and avoids evaluation deviations caused by differences in environmental conditions.

[0035] The formula for calculating the weighted average method in step S2 is as follows:

[0036] In the formula, H mix The target calorific value of the mixed gas is calculated as H when the higher calorific value is calculated. s , mix When calculating the lower heating value, it is H. i , mix The unit is MJ / m³; y i Let be the volume fraction of the i-th gas component in the gas mixture, and let y be the volume fraction of all components. i The sum equals 1; H i The calorific value of the i-th pure gaseous component under the standard conditions is H when calculating the higher calorific value. s , i When calculating the lower heating value, it is H. i , i The unit is MJ / m³; n is the total number of components in the gas mixture.

[0037] Specifically, the formula is based on the mole fraction weighting principle: in a gas mixture, the volume fraction of each component is equal to its mole fraction (Avogadro's law), and the mole fraction directly reflects the proportion of a component's amount of substance in the mixture, i.e., its contribution weight. The y-values ​​of all components... i The sum equaling 1 is a compositional constraint (mass conservation) for the gas mixture, ensuring logical consistency in the calculation. i Distinguishing high calorific value (H s , i ) and low calorific value (H i , i The purpose is to meet the needs of different engineering scenarios (such as the use of high calorific value for trade measurement and low calorific value for gas appliance design). The unit MJ / m³ is the standard unit of measurement for calorific value in the gas industry, ensuring data universality.

[0038] In one possible embodiment, the components of the mixed gas are hydrogen (H2), methane (CH4), ethane (C2H6), propane (C3H8), nitrogen (N2), and carbon dioxide (CO2), and the calorific value calculation formula is expanded as follows: H mix =y H2 ·H H2 +y CH4 ·H CH4 +y C2H6 ·H C2H6 +……+y N2 ·H N2 +y CO2 ·H CO2 In the formula, y H2 y CH4 yC2H6 y C3H8 y N2 y CO2 These are the volume fractions of each corresponding component, H H2 H CH4 H C2H6 H C3H8 H N2 H CO2 These are the target calorific values ​​of the corresponding components under the standard conditions.

[0039] Specifically, this expansion is a concrete application of the weighted average method. The selected components are typical components in a natural gas pipeline hydrogen blending scenario—methane (CH4) is the main component of natural gas, ethane (C2H6) and propane (C3H8) are common associated hydrocarbons, nitrogen (N2) and carbon dioxide (CO2) are common inert components in natural gas (they do not participate in combustion, only affecting calorific value and density), and hydrogen (H2) is the main blending component. The logic of the expansion is to calculate the contribution of each component and then sum them up. The calorific value (H2) of the inert components (N2, CO2) is... N2 H CO2 The contribution is extremely low (approximately 0), and its main contribution is the dilution effect (reducing the overall calorific value of the mixed gas). This form is in line with engineering practice and can be directly substituted into the component data of on-site testing for calculation, making it highly practical.

[0040] In one possible embodiment, the formula for calculating the Hua Bai Index in step S3 is:

[0041] In the formula, H s The volumetric calorific value of the mixed gas calculated in step S2 is expressed in MJ / m³, and s is the relative density of the mixed gas.

[0042] Specifically, the formula selects high calorific value (H) s The reason for using a higher calorific value (rather than a lower calorific value) is that the Wassell Index is used for appliance interchangeability assessment. A higher calorific value better reflects the total energy release potential of the gas and, combined with flow characteristics (relative density), can be used to match the design heat load of the appliance. The calculation logic for relative density (s) is the density of the mixed gas / the density of dry air, and its square root... It is positively correlated with the flow resistance of the gas. The essence of the formula is the balance ratio of energy potential to flow resistance. The closer the ratio is to the reference gas, the better the thermal load stability of the appliance and the stronger its interchangeability.

[0043] In one possible embodiment, the expression of the semi-empirical calculation model in step S4 is: CP = k1·(H2%) + k2·(∑(a) ᵢ ·CnHm%)) In the formula, H2% is the hydrogen gas integral, CnHm% is the volume fraction of various hydrocarbon gases, k1 and k2 are weighting coefficients related to combustion rate, and aᵢ is the characteristic coefficient of different hydrocarbon components. The semi-empirical and semi-computational approach, simplified to a linear form, is: CP=k1·x H2 +b CH4 ·x CH4 +b C2H6 ·x C2H6 +...+b CnHm ·x CnHm In the formula, b i =k2·a i x H2 x CH4 x C2H6 ...x CnHm These represent the volume percentages of hydrogen and each hydrocarbon component, respectively.

[0044] Specifically, hydrogen (H2%) and hydrocarbons (CnHm%) have different mechanisms of influence on combustion potential, therefore weighting coefficients k1 and k2 are set respectively; a ᵢ The coefficient represents the hydrocarbon characteristic coefficient because different hydrocarbons have significantly different combustion rates (e.g., propane burns faster than methane), and this coefficient is needed to distinguish their contribution weights. The simplified linear form is for ease of parameter fitting and calculation, letting b... i =k2·a i The double-weighted coefficients (k1, k2) are transformed into single-component coefficients (k1, b). CH4 b C2H6 (etc.), making the model a linear regression equation, which can quickly fit the coefficients through experimental data, while reducing the computational complexity in engineering applications and ensuring the ease of use of the model.

[0045] In one possible embodiment, the coefficients k1, k2, a ᵢ Determined in the following ways: Based on the reference gas conforming to GB / T13611, multiple mixed gas samples with hydrogen doping ratios of 0%-30% were prepared. The main combustion parameters, such as the laminar flame propagation velocity, of each gas sample were measured to obtain m sets of experimental data. Each set of data includes one measured value of combustion potential and the corresponding gas composition. Based on the m sets of experimental data, a matrix equation Y=Xβ is constructed, where Y is an m×1 column vector of the measured combustion potential values, X is an m×p design matrix, p is the number of independent variables (i.e., the number of combustible component types + 1), and β is a p×1 column vector of the regression coefficients to be determined [k1, b]. CH4 ,b C2H6 ,...] T ; Solve β=(X) using the least squares method T X) -1 X T Y, so that the average relative error between the calculated combustion potential and the experimental value is less than 10%.

[0046] Specifically, the logic for determining the coefficients involves experimental calibration and mathematical fitting to ensure the model's predictive accuracy. The reference gas specified in GB / T13611 is selected to align with the actual gas characteristics of my country's natural gas pipeline network and avoid reference deviations. A hydrogen blending ratio of 0%-30% covers the commonly used blending range in engineering, ensuring the model's effectiveness within practical applications. The laminar flame propagation velocity is a key parameter related to combustion potential; measured values ​​of this parameter directly reflect the intensity of combustion. The matrix equation Y=Xβ is the standard form of linear regression. The principle of the least squares method is to minimize the sum of squared residuals between the predicted and measured values. This is achieved by solving β=(Xβ... T X) -1 X T The optimal coefficients for Y are obtained, so that the average relative error is less than 10%, which meets the engineering accuracy requirements.

[0047] In one possible embodiment, the calorific value, the Wobbe index, and the combustion potential result determination criteria in step S5 are consistent with the requirements of the specifications GB17820 "Natural Gas", GB / Z33440-2016 "General Requirements for Interchangeability of Natural Gas Entering Long-Distance Pipeline Networks", and GB / T13611 "Classification and Basic Characteristics of Urban Gas".

[0048] Specifically, the three national standards focus on key quality indicators of natural gas, interchangeability requirements for long-distance pipelines, and classification and characteristics of urban gas, respectively, serving as the main compliance guidelines for the engineering application of hydrogen-blended natural gas. Calorific value is based on GB17820 to ensure energy supply quality; the Wasai index is based on GB / T13611 (allowing ±5% fluctuation for Class 12T natural gas) to ensure compatibility with end-use appliances; and combustion potential is based on GB / Z33440-2016 to control combustion stability risks. The judgment criteria are consistent with national standards, avoiding potential engineering problems caused by conflicting indicator limits and ensuring that the analysis results have industry recognition and compliance.

[0049] In one possible embodiment, step S6 further includes plotting a hydrogen doping ratio-combustion characteristic graph to visually reveal the correspondence between the hydrogen doping ratio and the combustion characteristics of the mixed gas.

[0050] Specifically, the value of the hydrogen blending ratio-combustion characteristics graph lies in its visual representation. The horizontal axis represents the hydrogen blending ratio (0%-30%), and the vertical axis represents the calorific value, Wobbe index, and combustion potential, respectively. The graph visually presents the trends of these three parameters with the hydrogen blending ratio through curves. The design logic of this graph is to quantify trends and provide intuitive judgment. Engineers can quickly locate the maximum safe hydrogen blending ratio (i.e., the maximum hydrogen blending ratio where all three indicators meet the limits) using the graph, eliminating the need for recalculation. This provides efficient visual support for the design and adjustment of hydrogen blending schemes, improving the convenience of engineering applications.

[0051] The application scenarios of this invention are as follows: In the field of hydrogen-blended natural gas transportation engineering design, this invention is applicable to the design of new hydrogen-blended natural gas pipeline networks or the retrofitting of existing natural gas pipeline networks. In such scenarios, it is necessary to determine the maximum safe hydrogen blending ratio for the pipeline network to avoid defects such as insufficient energy and poor compatibility during the design phase. This invention, by inputting basic data such as natural gas composition and the proposed hydrogen blending ratio, uses a weighted average method and a semi-empirical calculation model to calculate the calorific value, Wobbe index, and combustion potential of the mixed gas. By cross-referencing with national standards such as GB17820 and GB / Z33440-2016, a compliant range of hydrogen blending ratios can be determined. This provides quantitative data support for pipeline diameter selection, pressure design, and terminal adaptation retrofitting, avoiding potential engineering design problems caused by inappropriate hydrogen blending ratios.

[0052] In the existing natural gas pipeline network hydrogen blending operation field: This invention is applicable to the daily operation adjustment scenarios of existing hydrogen-blended natural gas pipeline networks. In such scenarios, the natural gas composition may change due to fluctuations in gas source or the hydrogen blending ratio may need to be adjusted according to the hydrogen energy supply. Ensuring the continuous and stable operation of the pipeline network is crucial. This invention, through modular calculation and cross-analysis of national standards, quickly verifies the compliance of the three major indicators under the new hydrogen blending ratio. It can promptly trigger early warnings and output optimization suggestions (such as adjusting the hydrogen blending ratio or supplementing specific hydrocarbon components), providing a scientific basis for adjusting operating parameters and avoiding pipeline operation fluctuations and safety risks caused by excessive Wobbe Index or excessively high combustion potential.

[0053] In the field of gas appliance compatibility verification, this invention is applicable to the verification of hydrogen blending compatibility of existing gas appliances (household stoves, commercial boilers, industrial kilns, etc.) or the development of new hydrogen-blended gas appliances. In such scenarios, it is necessary to ensure that the gas appliances are compatible with hydrogen-blended natural gas to avoid combustion malfunctions. This invention, by calculating the Wobbe Index (controlling the fluctuation range of 12T Class natural gas ±5%) and combustion potential under different hydrogen blending ratios, can assess flame stability, backfire risk, and heat load stability. This provides a technical basis for adjusting the appliance damper and optimizing the burner structure, avoiding problems such as incomplete combustion, flame detachment, and equipment overheating damage.

[0054] In the field of hydrogen-blended natural gas metering and trading: This invention is applicable to settlement scenarios involving the trading of hydrogen-blended natural gas. In such scenarios, it is necessary to measure the calorific value of the mixed gas to ensure fair trade. This invention uses a weighted average method based on measured data of natural gas composition and hydrogen blending ratio to calculate the higher and lower calorific values ​​of the mixed gas. This ensures that the metering results meet the quality requirements of GB17820, providing accurate energy data support for trade pricing and avoiding trade disputes between supply and demand parties caused by deviations in calorific value calculation.

[0055] In the field of gas pipeline safety assessment, this invention is applicable to daily safety monitoring, periodic risk assessment, and emergency response scenarios for hydrogen-blended natural gas pipelines. These scenarios require dynamic control of safety risks such as deflagration and terminal appliance malfunctions. This invention rapidly calculates combustion potential (assessing deflagration risk) and the Wobbe index (assessing appliance stability) by inputting the pipeline gas composition and hydrogen blending ratio in real time. Combined with national standards, it dynamically judges the safety status and can immediately trigger an over-limit warning, providing a basis for maintenance personnel to take emergency measures such as pressure reduction and adjusting the hydrogen blending ratio, thus preventing the escalation of safety accidents such as deflagration and terminal equipment malfunctions after a leak.

[0056] Applications of hydrogen-blended natural gas standards: This invention is applicable to the formulation and revision of national standards such as the "Technical Requirements for Hydrogen-Blended Natural Gas Pipeline Transportation" and the implementation of existing national standards (GB / Z33440-2016, etc.) in hydrogen blending scenarios. In these scenarios, standardized technical methods are required to ensure the feasibility of the standards. This invention constructs a comprehensive calculation and evaluation system encompassing energy, interchangeability, and safety dimensions. It provides measured data support and calculation method references for setting maximum hydrogen blending ratio limits and combustion characteristic index requirements for new national standards. It also provides enterprises with a unified and standardized technical tool to implement national standard requirements, avoiding the problems of inconsistent implementation and lack of unified methods.

[0057] In the research field of hydrogen energy and gas fusion, this invention is applicable to fundamental research on the combustion characteristics of hydrogen-blended natural gas, experimental verification of novel blending technologies (such as gradient hydrogen blending), and optimization of combustion models. These scenarios require rapid quantification of combustion characteristics to support the transformation of research results. Through modular design and computational capabilities, this invention rapidly quantifies three main indicators under different hydrogen blending ratios and different natural gas compositions. This quantification can be cross-validated with experimentally measured data (such as laminar flame propagation speed), providing data support for combustion kinetic model optimization and research on the effects of hydrogen blending, thus accelerating the transformation of research results into engineering applications.

[0058] In the field of cross-regional hydrogen-blended natural gas dispatching: This invention is applicable to scenarios involving multiple gas sources and cross-regional hydrogen-blended natural gas dispatching and distribution. In such scenarios, it is necessary to ensure that the blended hydrogen-blended natural gas from different sources still meets the requirements of pipeline operation and end-user use. This invention assesses the compliance of the overall characteristics after blending by uniformly calculating the calorific value, Wobbe index, and combustion potential of gases from different sources and comparing them with national standards. This provides guidance for dispatchers to rationally allocate the delivery ratio of each gas source, avoiding exceeding the standards due to gas blending and ensuring stable gas supply across cross-regional pipeline networks. Example

[0059] See Figure 3 This invention provides a comprehensive analysis device for hydrogen-blended combustion characteristics of natural gas pipelines, employing the aforementioned comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines, including: Data input unit 100: used to input basic data, including the composition of natural gas and the volume fraction of each component, the volume fraction of hydrogen blending, and the standard higher calorific value and standard lower calorific value of each pure component under standard conditions. Calorific value calculation unit 200: Used to calculate the volumetric calorific value and volumetric calorific value of a gas mixture based on thermodynamic principles and using a weighted average method, thereby quantifying the basic energy characteristics; The Warburg index calculation unit 300 is used to calculate the relative density of the mixed gas under the standard state based on the volumetric calorific value of the mixed gas described in the calorific value calculation unit 200, and then calculate the Warburg index of the mixed gas according to the internationally accepted definition of the Warburg index, thereby realizing the quantification of interchangeability index. Combustion potential calculation unit 400: is used to construct a semi-empirical calculation model based on the principle of combustion dynamics, which comprehensively considers the high combustion rate of hydrogen and the different contributions of different hydrocarbon gases to flame characteristics. The combustion potential of the mixed gas is calculated through the semi-empirical calculation model to complete the quantification of safety and stability indicators. National Standard Comparison Unit 500: Used to establish a national standard cross-comparison mechanism, which verifies the compliance of the calorific value, the Wobbe index, and the combustion potential results obtained by the calorific value calculation unit 200, the Wobbe index calculation unit 300, and the combustion potential calculation unit 400 against the requirements of the national standard documents. Decision result output unit 600: Used to verify whether the calorific value, the fluctuation range of the Huabai index and the combustion potential simultaneously meet all the requirements of risk control by adopting multi-indicator collaborative decision judgment logic. If all are met, the feasible conclusion of the scheme is output; if any indicator exceeds the standard, an early warning is triggered and optimization suggestions are output.

[0060] It should be noted that the information interaction and execution process between the modules of the above-mentioned device are based on the same concept as the method embodiment in Embodiment 1 of this application, and the resulting technical effects are the same as those in the method embodiment of this application. For details, please refer to the description in the method embodiment shown above in this application, and it will not be repeated here. Example

[0061] Embodiment 3 of the present invention provides a non-transitory computer-readable storage medium, wherein the computer-readable storage medium stores program code for a comprehensive analysis method and apparatus for hydrogen-blended combustion characteristics of natural gas pipelines, and the program code includes instructions for executing the comprehensive analysis method and apparatus for hydrogen-blended combustion characteristics of natural gas pipelines of Embodiment 1 or any possible implementation thereof.

[0062] Computer-readable storage media can be any available medium that a computer can access, or a data storage device such as a server or data center that integrates one or more available media. The available medium can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)). Example

[0063] Embodiment 4 of the present invention provides an electronic device, including: a memory and a processor; The processor and the memory communicate with each other via a bus; the memory stores program instructions that can be executed by the processor, and the processor can call the program instructions to execute the comprehensive analysis method and apparatus for hydrogen-blended combustion characteristics of natural gas pipelines in Embodiment 1 or any possible implementation thereof.

[0064] Specifically, a processor can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, an integrated circuit, etc. When implemented in software, the processor can be a general-purpose processor that reads software code stored in memory. This memory can be integrated into the processor or located outside the processor and exist independently.

[0065] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable system. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0066] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing systems. They can be centralized on a single computing system or distributed across a network of multiple computing systems. Optionally, they can be implemented using program code executable by a computing system, thereby storing them in a storage system for execution by the computing system. In some cases, the steps shown or described can be performed in a different order than those presented herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0067] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A comprehensive analysis method for the hydrogen-blended combustion characteristics of natural gas pipelines, characterized in that, include: S1. Input basic data, which includes the composition of natural gas and the volume fraction of each component, the volume fraction of hydrogen blending, and the standard higher calorific value and standard lower calorific value of each pure component under standard conditions. S2. Based on thermodynamic principles, the weighted average method is used to calculate the volumetric higher heating value and volumetric lower heating value of the mixed gas, thus completing the quantification of the basic energy characteristics. S3. Based on the volumetric calorific value of the mixed gas described in step S2, first calculate the relative density of the mixed gas under the standard conditions, and then calculate the Wobbe index of the mixed gas according to the internationally accepted definition of the Wobbe index to achieve the quantification of interchangeability index. S4. Based on the principles of combustion dynamics, a semi-empirical calculation model is constructed that comprehensively considers the high combustion rate of hydrogen and the differentiated contributions of different hydrocarbon gases to flame characteristics. The combustion potential of the mixed gas is calculated through the semi-empirical calculation model to complete the quantification of safety and stability indicators. S5. Establish a national standard cross-comparison mechanism, and verify the compliance of the calorific value, the Wobbe index, and the combustion potential results obtained in steps S2, S3, and S4 against the requirements of national standard documents. S6. Using a multi-indicator collaborative decision-making logic, verify whether the calorific value, the fluctuation range of the Huabai index, and the combustion potential simultaneously meet all the requirements of risk control. If all are met, output a feasible conclusion for the solution; if any indicator exceeds the standard, trigger an early warning and output optimization suggestions.

2. The comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines according to claim 1, characterized in that, The target calorific value of the mixed gas under standard conditions is 101.325 kPa and 20 °C.

3. The comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines according to claim 1, characterized in that, The formula for calculating the weighted average method in step S2 is as follows: ， In the formula, H mix The target calorific value of the mixed gas is calculated as H when the higher calorific value is calculated. s , mix When calculating the lower heating value, it is H. i , mix ; y i Let be the volume fraction of the i-th gas component in the gas mixture, and let y be the volume fraction of all components. i The sum equals 1; H i The calorific value of the i-th pure gaseous component under the standard conditions is H when calculating the higher calorific value. s , i When calculating the lower heating value, it is H. i , i ; n is the total number of components in the gas mixture.

4. The comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines according to claim 3, characterized in that, The components of the mixed gas are hydrogen (H2), methane (CH4), ethane (C2H6), propane (C3H8), nitrogen (N2), and carbon dioxide (CO2). The formula for calculating the calorific value is as follows: H mix =y H2 ·H H2 +y CH4 ·H CH4 +y C2H6 ·H C2H6 +……+y N2 ·H N2 +y CO2 ·H CO2 In the formula, y H2 y CH4 y C2H6 y C3H8 y N2 y CO2 These are the volume fractions of each corresponding component, H H2 H CH4 H C2H6 H C3H8 H N2 H CO2 These are the target calorific values ​​of the corresponding components under the standard conditions.

5. The comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines according to claim 1, characterized in that, The formula for calculating the Hua Bai Index in step S3 is as follows: ， In the formula, H s The volumetric calorific value of the mixed gas is calculated in step S2, and s is the relative density of the mixed gas.

6. The comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines according to claim 1, characterized in that, The expression for the semi-empirical calculation model in step S4 is: CP=k1·(H2%)+k2·(∑(a ᵢ ·CnHm%)) In the formula, H2% is the hydrogen gas integral, CnHm% is the volume fraction of various hydrocarbon gases, k1 and k2 are weighting coefficients related to combustion rate, and aᵢ is the characteristic coefficient of different hydrocarbon components. The semi-empirical calculation model simplifies to a linear form as follows: CP=k1·x H2 +b CH4 ·x CH4 +b C2H6 ·x C2H6 +...+b CnHm ·x CnHm In the formula, x H2 x CH4 x C2H6 ...x CnHm These represent the volume percentages of hydrogen and each hydrocarbon component, respectively.

7. The comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines according to claim 6, characterized in that, Coefficients k1, k2, a ᵢ Determined in the following ways: Based on the reference gas conforming to GB / T13611, multiple mixed gas samples with hydrogen doping ratios of 0%-30% were prepared. The main combustion parameters, such as the laminar flame propagation velocity, of each gas sample were measured to obtain m sets of experimental data. Each set of data includes one measured value of combustion potential and the corresponding gas composition. Based on the m sets of experimental data, a matrix equation Y=Xβ is constructed, where Y is an m×1 column vector of the measured combustion potential values, X is an m×p design matrix, p is the number of independent variables (i.e., the number of combustible component types + 1), and β is a p×1 column vector of the regression coefficients to be determined [k1, b]. CH4 ,b C2H6 ,...] T ; Solve β=(X) using the least squares method T X) -1 X T Y, so that the average relative error between the calculated combustion potential and the experimental value is less than 10%.

8. The comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines according to claim 1, characterized in that, The criteria for determining the calorific value, the Wobbe index, and the combustion potential in step S5 are consistent with the requirements of the standards GB17820 "Natural Gas", GB / Z33440-2016 "General Requirements for Interchangeability of Natural Gas Entering Long-Distance Pipeline Networks", and GB / T13611 "Classification and Basic Characteristics of Urban Gas".

9. The comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines according to claim 1, characterized in that, Step S6 also includes plotting a hydrogen doping ratio-combustion characteristic graph to reveal the correspondence between the hydrogen doping ratio and the combustion characteristics of the mixed gas.

10. A comprehensive analysis device for hydrogen-blended combustion characteristics of natural gas pipelines, employing the comprehensive analysis method for hydrogen-blended combustion characteristics of natural gas pipelines as described in any one of claims 1-9, characterized in that, include: Data input unit: used to input basic data, including the composition of natural gas and the volume fraction of each component, the volume fraction of hydrogen blending, and the standard higher calorific value and standard lower calorific value of each pure component under standard conditions. Calorific value calculation unit: used to calculate the volumetric calorific value and volumetric calorific value of a gas mixture based on thermodynamic principles and using a weighted average method, thereby quantifying the basic energy characteristics; The Warburg Index Calculation Unit is used to calculate the relative density of the mixed gas under standard conditions based on the volumetric calorific value of the mixed gas in the calorific value calculation unit, and then calculate the Warburg Index of the mixed gas according to the internationally accepted definition of the Warburg Index, thereby realizing the quantification of interchangeability indicators. Combustion potential calculation unit: Based on the principles of combustion dynamics, it constructs a semi-empirical calculation model that comprehensively considers the high combustion rate of hydrogen and the differentiated contributions of different hydrocarbon gases to flame characteristics. The combustion potential of the mixed gas is calculated through the semi-empirical calculation model to complete the quantification of safety and stability indicators. National Standard Comparison Unit: Used to establish a national standard cross-comparison mechanism, which verifies the compliance of the calorific value, the Wobbe index, and the combustion potential results obtained by the calorific value calculation unit, the Wobbe index, and the combustion potential calculation unit against the requirements of the national standard documents one by one. Decision result output unit: Used to verify whether the calorific value, the fluctuation range of the Huabai index, and the combustion potential simultaneously meet all the requirements of risk control by adopting multi-indicator collaborative decision judgment logic. If all are met, the feasible conclusion of the scheme is output; if any indicator exceeds the standard, an early warning is triggered and optimization suggestions are output.

Images