Linkage method of safety verification and real-time prediction linkage system for hydrogen-blended natural gas pipeline network

Abstract

The present invention provides a linkage method for the safety verification and real-time prediction linkage system of the hydrogen-blended natural gas pipeline network, including a digital twin module, a detection module, a hydrogen-blending skid module and a usage prediction module; the detection module includes a terminal user, a thermometer and a flow meter, the thermometer is used to collect the temperature data of the terminal user, the temperature data is transmitted to the digital twin module, the flow meter is used to collect the load data of the terminal user, the load data is transmitted to the usage prediction module; the usage prediction module predicts the hydrogen-blended natural gas usage of the user per hour in real time according to the data collected by the detection module; the hydrogen-blending skid module controls the mixing ratio of hydrogen and natural gas according to the output result of the usage prediction module; the digital twin module verifies the feasibility of safe operation and the hydrogen-blending ratio by calculating the physical properties of the hydrogen-blended natural gas. Accurate prediction, dynamic scheduling and safety verification of natural gas and hydrogen usage are achieved to ensure the improvement of energy efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen-blended natural gas transportation, and in particular to a linkage method for a hydrogen-blended natural gas pipeline network safety verification and real-time prediction linkage system. Background Art

[0002] With the energy transformation and the improvement of environmental protection requirements, hydrogen energy has received widespread attention as a clean and efficient energy source. In terms of the transportation and storage of hydrogen energy, using existing natural gas pipelines or pipeline networks to transport natural gas mixed with hydrogen is an economical and efficient way.

[0003] With the increase in demand for clean energy, hydrogen energy as an efficient, zero-carbon emission energy has gradually attracted attention; hydrogen-blended natural gas can effectively reduce carbon emissions by mixing a certain proportion of hydrogen into natural gas; however, due to the significant difference between the characteristics of hydrogen and natural gas, hydrogen may affect the existing pipeline network and equipment after blending. Therefore, how to accurately predict the amount of hydrogen and ensure the safe operation of the pipeline network is a key technical problem; although the existing technology has explored the feasibility of natural gas blending with hydrogen, it still has deficiencies in real-time prediction, dynamic scheduling and safety verification. The existing technology lacks efficient prediction methods for real-time data, making it difficult to adjust the hydrogen blending ratio in time to cope with load fluctuations; lacks a dynamic scheduling mechanism, making it difficult to achieve accurate ratio control of hydrogen and natural gas; insufficient safety verification methods, lack of real-time monitoring, operation simulation and dynamic verification of key parameters such as pressure and temperature of the hydrogen-blended pipeline network, resulting in safety hazards in the hydrogen blending process, making it difficult to ensure the stable and safe operation of hydrogen-blended natural gas; therefore, a comprehensive solution integrating prediction, scheduling and safety verification is urgently needed to improve the application effect of hydrogen-blended natural gas. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a linkage method for the safety verification and real-time prediction linkage system of a hydrogen-blended natural gas pipeline network. Through real-time data collection, usage prediction and pipeline network safety verification, accurate prediction, dynamic scheduling and safety verification of natural gas and hydrogen usage are achieved, ensuring that carbon emissions are reduced while improving energy utilization efficiency, ensuring the safe operation of hydrogen-blended natural gas in complex pipeline networks, and promoting the widespread application of clean energy.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A linkage method for a hydrogen-blended natural gas pipeline network safety verification and real-time prediction linkage system, the linkage method comprising the following steps:

[0007] S1. The detection module collects basic parameter data of the terminal user's pipe network through thermometers and flow meters, and the basic parameter data is transmitted to the digital twin module and the usage prediction module;

[0008] S2, the digital twin module collects the pipeline network information of the end users and builds a dynamic simulation model of the pipeline network; verifies the feasibility of safe operation and dynamically adjusts the hydrogen blending ratio;

[0009] S3. The hydrogen blending ratio calculated by the digital twin module is input into the usage prediction module for data preprocessing;

[0010] S4. According to the prediction processing result of the usage prediction module, the demand for hydrogen is calculated and determined, and the demand for hydrogen is sent to the PEM water electrolysis hydrogen production module. The hydrogen generated by the PEM water electrolysis hydrogen production module is transported to the hydrogen doping skid module through valve B. When the amount of hydrogen generated by the PEM water electrolysis hydrogen production module is insufficient, the hydrogen storage tank replenishes hydrogen to the hydrogen doping skid module through valve A. When the amount of hydrogen generated is greater than the demand, the PEM water electrolysis hydrogen production module stores the excess hydrogen in the hydrogen storage tank through valve C.

[0011] In step S4, the calculation determines the demand for hydrogen as follows:

[0012] (five)

[0013] In formula (5), The actual hydrogen delivery volume for the hydrogen blending skid; The hydrogen demand in the hydrogen dosing skid module; is the available amount of hydrogen in the hydrogen storage tank; is the balance coefficient;

[0014] (six)

[0015] In formula (6), is the final determined hydrogen blending ratio; The node load demand for hydrogen-blended natural gas; is the natural gas node load demand;

[0016] The formula is derived from the density ratio of natural gas and hydrogen as follows:

[0017] (seven)

[0018] In formula (VII), is the hydrogen demand fed back to the hydrogen blending skid; α is the gain parameter for hydrogen blending ratio control; β is the gain parameter for load prediction weight; is the current pressure of the natural gas system;

[0019] The linkage system comprises a digital twin module (1), a detection module (5), a hydrogen doping skid module (6) and a usage prediction module (11);

[0020] The detection module (5) comprises a terminal user (2), a thermometer (3) and a flow meter (4), wherein the thermometer (3) is used to collect temperature data of the terminal user (2), and the temperature data is transmitted to the digital twin module (1); and the flow meter (4) is used to collect load data of the terminal user (2), and the load data is transmitted to the usage prediction module (11);

[0021] The usage prediction module (11) predicts the user's hourly usage of hydrogen-blended natural gas in real time based on the data collected by the detection module (5);

[0022] The hydrogen blending skid module (6) controls the mixing ratio of hydrogen and natural gas according to the prediction result of the usage prediction module (11);

[0023] The digital twin module (1) verifies the feasibility of safe operation and dynamically adjusts the hydrogen blending ratio by calculating the physical property parameters of hydrogen-blended natural gas;

[0024] The calculation of the physical property parameters of hydrogen-blended natural gas includes density calculation, high calorific value calculation, and load conversion calculation;

[0025] The density is calculated as follows:

[0026] (one)

[0027] In formula (1), is the density of natural gas after mixing with hydrogen; is the hydrogen incorporation ratio; is the density of natural gas; is the density of hydrogen;

[0028] The high calorific value is calculated as follows:

[0029] (two)

[0030] In formula (2), The high calorific value of hydrogen-blended natural gas; It is the high calorific value of natural gas; It is the high calorific value of hydrogen;

[0031] The load conversion calculation is as follows:

[0032] (three)

[0033] In formula (3), is the node load of hydrogen-blended natural gas; is the node load of natural gas.

[0034] The safe operation feasibility includes pressure verification, temperature verification and node load non-negative verification;

[0035] The pressure check is ,in, Provides the minimum pressure limit for pipe network operation; is the pressure at a node in the pipe network; It is the maximum pressure limit for pipe network operation;

[0036] The temperature check is ,in, Minimum temperature limit for pipe network operation; is the temperature of a node in the pipe network; It is the maximum temperature limit for pipe network operation;

[0037] The node load non-negative check is: ,in, is the load of a node in the pipeline network.

[0038] The dynamic adjustment of hydrogen blending ratio is as follows:

[0039] (Four)

[0040] In formula (IV), is the final hydrogen blending ratio; is the maximum pressure deviation; is the maximum temperature deviation; is the actual pressure error; is the actual temperature error; is the maximum hydrogen doping ratio.

[0041] The system also includes valve A, a hydrogen storage tank, valve B, valve C and a PEM water electrolysis hydrogen production module;

[0042] The PEM water electrolysis hydrogen production module and the hydrogen storage tank are dynamically linked according to the demand for hydrogen to ensure the supply of hydrogen. The hydrogen storage tank is used to replenish the hydrogen when the hydrogen production is insufficient, and store the hydrogen in the hydrogen storage tank when the production is excessive.

[0043] The PEM water electrolysis hydrogen production module transports hydrogen to the hydrogen doping skid module through valve B; the PEM water electrolysis hydrogen production module transports hydrogen to the hydrogen storage tank through valve C, and the hydrogen storage tank transports hydrogen to the hydrogen doping skid module through valve A.

[0044] The beneficial effects of the present invention are:

[0045] 1. Ensure accurate supply by calculating the physical properties of hydrogen-blended natural gas and dynamically adjusting the mixing ratio of hydrogen and natural gas. Establish a digital twin module based on the existing pipeline network to evaluate and verify the safety of hydrogen-blended natural gas in real time to ensure stable operation of the pipeline network. Combined with the cooperation of hydrogen storage tanks and intelligent valves, flexible storage and dynamic supply of hydrogen can be achieved to ensure the stability of hydrogen supply. The modules of the system are highly coordinated, integrating data collection, usage prediction, hydrogen blending control and safety verification to achieve integrated management. The system is simple to operate, has a reasonable structure and high safety. Through real-time data collection and prediction, accurate supply of hydrogen-blended natural gas can be achieved, and real-time verification can be performed through the digital twin module to ensure the safety and stability of the pipeline network and avoid safety risks caused by excessive hydrogen blending. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the connection structure of the present invention.

[0047] As shown in the figure: 1-digital twin module; 2-end user; 3-thermometer; 4-flow meter; 5-detection module; 6-hydrogen doping skid module; 7-valve A; 8-hydrogen storage tank; 9-valve B; 10-valve C; 11-usage prediction module; 12-PEM water electrolysis hydrogen production module. DETAILED DESCRIPTION

[0048] The present invention is further described below in conjunction with the accompanying drawings and embodiments. Example

[0049] like Figure 1 As shown, a linkage method of a hydrogen-blended natural gas pipeline network safety verification and real-time prediction linkage system, the linkage system includes a digital twin module 1, a detection module 5, a hydrogen-blending skid module 6 and a usage prediction module 11;

[0050] The detection module 5 includes a terminal user 2, a thermometer 3 and a flow meter 4. The thermometer 3 is used to collect temperature data of the terminal user 2, and the temperature data is transmitted to the digital twin module 1. The flow meter 4 is used to collect load data of the terminal user 2, and the load data is transmitted to the usage prediction module 11.

[0051] The usage prediction module 11 predicts the user's hourly usage of hydrogen-blended natural gas in real time based on the data collected by the detection module 5;

[0052] The hydrogen blending skid module 6 controls the mixing ratio of hydrogen and natural gas according to the prediction result of the usage prediction module 11;

[0053] The digital twin module 1 verifies the feasibility of safe operation and dynamically adjusts the hydrogen blending ratio by calculating the physical properties of hydrogen-blended natural gas;

[0054] The calculation of the physical property parameters of hydrogen-blended natural gas includes density calculation, high calorific value calculation, and load conversion calculation;

[0055] The density is calculated as follows:

[0056] (one)

[0057] In formula (1), is the density of natural gas after mixing with hydrogen; is the hydrogen incorporation ratio; is the density of natural gas; is the density of hydrogen;

[0058] The high calorific value is calculated as follows:

[0059] (two)

[0060] In formula (2), The high calorific value of hydrogen-blended natural gas; It is the high calorific value of natural gas; It is the high calorific value of hydrogen;

[0061] The load conversion calculation is as follows:

[0062] (three)

[0063] In formula (3), is the node load of hydrogen-blended natural gas; is the node load of natural gas.

[0064] The safe operation feasibility includes pressure verification, temperature verification and node load non-negative verification;

[0065] The pressure check is ,in, Provides the minimum pressure limit for pipe network operation; is the pressure at a node in the pipe network; It is the maximum pressure limit for pipe network operation;

[0066] The temperature check is ,in, Minimum temperature limit for pipe network operation; is the temperature of a node in the pipe network; It is the maximum temperature limit for pipe network operation;

[0067] The node load non-negative check is: ,in, is the load of a node in the pipeline network.

[0068] The hydrogen blending ratio starts from 30% and decreases by 2% each time, and the calculation is repeated until the safe operation conditions are met or the hydrogen blending ratio drops to zero. If all parameters meet the set safety thresholds, the digital twin module 1 will send a hydrogen blending control signal to start the hydrogen blending skid module 6;

[0069] The dynamic adjustment of hydrogen blending ratio is as follows:

[0070] (Four)

[0071] In formula (IV), is the final hydrogen blending ratio; is the maximum pressure deviation; is the maximum temperature deviation; is the actual pressure error; is the actual temperature error; is the maximum hydrogen doping ratio.

[0072] The system also includes valve A7, hydrogen storage tank 8, valve B9, valve C10 and PEM water electrolysis hydrogen production module 12;

[0073] The PEM water electrolysis hydrogen production module 12 and the hydrogen storage tank 8 are dynamically linked according to the demand for hydrogen to ensure the supply of hydrogen. The hydrogen storage tank 8 is used to replenish the hydrogen when the hydrogen production is insufficient, and to store the hydrogen in the hydrogen storage tank 8 when the production is excessive.

[0074] The PEM water electrolysis hydrogen production module 12 delivers hydrogen to the hydrogen doping skid module 6 through valve B9; the PEM water electrolysis hydrogen production module 12 delivers hydrogen to the hydrogen storage tank 8 through valve C10, and the hydrogen storage tank 8 delivers hydrogen to the hydrogen doping skid module 6 through valve A7.

[0075] The PEM water electrolysis hydrogen production module 12 is a device for preparing hydrogen;

[0076] The linkage method comprises the following steps:

[0077] S1, the detection module 5 collects the basic parameter data of the pipe network of the end user 2 through the thermometer 3 and the flow meter 4, and the basic parameter data is transmitted to the digital twin module 1 and the usage prediction module 11;

[0078] The detection module 5 collects the basic parameters of the pipe network of the terminal user 2 in real time through sensors such as the thermometer 3 and the flow meter 4, such as pressure, load, temperature, climate, date and other data. The load, temperature, climate and date data are required to be at least one year in volume. The data from 8:00 to 22:00 every day of the previous year must be collected, and a sample is collected every hour to ensure the accuracy of the prediction. The current basic parameters of the pipe network and the current pressure and load data will be transmitted to the digital twin module 1, and the historical load, temperature, climate and date data will be transmitted to the usage prediction module 11.

[0079] S2, digital twin module 1 collects the pipeline network information of end user 2 and constructs a dynamic simulation model of the pipeline network; verifies the feasibility of safe operation and dynamically adjusts the hydrogen blending ratio;

[0080] The physical property calculation of hydrogen-blended natural gas includes density calculation, high calorific value calculation, and load conversion; the steady-state calculation of the pipeline network of hydrogen-blended natural gas includes node equations, pipe segment equations, and temperature calculation. The threshold alarm mechanism refers to feasibility verification, collecting the pipeline network information of the end user 2, including initial conditions such as load, pressure, and temperature, and building a dynamic simulation model of the pipeline network. When this module is used for the first time, the topological structure of the pipeline network and the initial conditions of each pipe segment need to be input to establish a digital twin module 1; the physical property calculation requires the collection of gas components, which are detected by a gas component detector;

[0081] S3. The hydrogen blending ratio and volume load calculated by the digital twin module 1 are input into the usage prediction module 11 for data preprocessing;

[0082] S4. According to the prediction processing result of the usage prediction module 11, the demand for hydrogen is calculated and determined, and the demand for hydrogen is sent to the PEM water electrolysis hydrogen production module 12. The hydrogen generated by the PEM water electrolysis hydrogen production module 12 is transported to the hydrogen doping skid module 6 through valve B9. When the amount of hydrogen generated by the PEM water electrolysis hydrogen production module 12 is insufficient, the hydrogen storage tank 8 replenishes hydrogen to the hydrogen doping skid module 6 through valve A7. When the amount of hydrogen generated is greater than the demand, the PEM water electrolysis hydrogen production module 12 stores the excess hydrogen in the hydrogen storage tank 8 through valve C10.

[0083] In step S4, the calculation determines the demand for hydrogen as follows:

[0084] (five)

[0085] In formula (5), The actual hydrogen delivery volume for the hydrogen blending skid; The hydrogen demand in the hydrogen dosing skid module; is the available amount of hydrogen in the hydrogen storage tank; is the balance coefficient;

[0086] (six)

[0087] In formula (6), is the final determined hydrogen blending ratio; The node load demand for hydrogen-blended natural gas; is the natural gas node load demand.

[0088] In order to dynamically control the hydrogen demand and perform real-time calculations to adapt to real-time changes in system load, a formula is derived from the density ratio of natural gas and hydrogen, as follows:

[0089] (seven)

[0090] In formula (VII), The hydrogen demand fed back to the hydrogen blending skid; is the gain parameter for hydrogen doping ratio control; is the gain parameter of load forecast weight; is the current pressure of the natural gas system.

[0091] In step S3, the data preprocessing is performed as follows:

[0092] S3.1, Normalization processing:

[0093] (eight)

[0094] In formula (8), min_val is the minimum value of the collected load; max_val is the maximum value of the collected load; the normalized output data set (x_train, x_test) is filtered, and the data in the data set (x_train, x_test) are filtered one by one during the filtering process;

[0095] S3.2, Exponential Weighted Moving Average (EWMA) Filter:

[0096] (Nine)

[0097] In formula (9), It is a load data after filtering and smoothing by the prediction module ewma; It is a certain hydrogen-blended natural gas load data obtained after normalization of the digital twin module; is the smoothing coefficient, , where the smoothing coefficient of the filter is set to 3.58, which can be adjusted according to different data sets; The smoothed data of the previous time step. The superscript prep indicates the result of the preprocessing step.

[0098] S3.3, GRU model:

[0099] Update the gate as follows:

[0100] (ten)

[0101] In formula (10), To update the gate, control the influence of the previous state; is the Sigmoid activation function; is the weight matrix of the update gate; is the concatenation of the hidden state of the previous time step and the current input, is the bias of the update gate, and the subscript pred indicates that all variables are designed according to the usage prediction module;

[0102] Reset the gate as follows:

[0103] (eleven)

[0104] In formula (XI), To reset the gate, control the degree of dependence on the previous state; is the weight matrix of the reset gate; To reset the bias of the gate, the subscript pred indicates that all variables are designed according to the usage prediction module;

[0105] The candidate activation states are as follows:

[0106] (twelve)

[0107] In formula (12), is the candidate activation state, tanh is the hyperbolic tangent activation function; is the weight matrix of the candidate state; is the bias of the candidate state; the subscript pred indicates that all variables are designed according to the usage prediction module;

[0108] The final hidden state is as follows:

[0109] (Thirteen)

[0110] In formula (13), is the hidden state of the current time step; To balance the ratio between the previous state and the current candidate state, the subscript pred indicates that all variables are designed according to the usage prediction module;

[0111] S3.4, Multi-head Attention Mechanism:

[0112] The calculation of query, key and value is as follows:

[0113] (fourteen)

[0114] In formula (14), They are query, key and value matrices respectively. They are the corresponding matrices respectively, and the subscript pred indicates that all variables are designed according to the usage prediction module;

[0115] Scale the dot product attention as follows:

[0116] (fifteen)

[0117] In formula (15), represents the result of the scaled dot product attention calculation, represents the calculated query matrix, represents the calculated bond matrix, represents the calculated value matrix, represents the transposed matrix of the calculated key matrix, Indicates the query / key dimension, used to scale the dot product result;

[0118] The multi-head attention mechanism performs weighted calculation on the time series features to ensure that the model can focus on the important features at different time steps. It then combines global average pooling to reduce the dimension and process the prediction results to obtain the hourly prediction results of hydrogen-blended natural gas and hydrogen consumption.

[0119] S3.5, Usage forecast process:

[0120] Input Features , the data set is divided by sliding window. The optimal number of sliding windows is 5. The input features are 8, which are the load data of the previous 5 hours, the temperature, weather and date at the required prediction time. After the data set is divided, normalization and filtering are performed to obtain the load , and then the dataset is encoded with GRU hidden state sequence , multi-head attention enhancement , input the enhanced features into the fully connected layer and then output , is the weight and bias of the fully connected layer, and the final output is the demand for hydrogen-blended natural gas Demand for natural gas and hydrogen ;

[0121] S3.6, load forecast error correction and feedback, as follows:

[0122] (sixteen)

[0123] In formula (16), is the actual measured value of the load, is the error feedback coefficient, which is set according to the actual system. This formula is based on error feedback control and corrects the calculation through the difference between the actual load and the predicted load to improve the accuracy of load prediction.

[0124] By calculating the physical properties of hydrogen-blended natural gas and dynamically adjusting the mixing ratio of hydrogen and natural gas, accurate supply is ensured. A digital twin module is established based on the existing pipeline network to evaluate and verify the safety of hydrogen-blended natural gas in real time to ensure stable operation of the pipeline network. The hydrogen storage tank 8 is combined with the intelligent valve to achieve flexible storage and dynamic supply of hydrogen to ensure the stability of hydrogen supply. The various modules of the system are highly coordinated, integrating data collection, usage prediction, hydrogen blending control and safety verification to achieve integrated management. The system is simple to operate, has a reasonable structure and high safety. Through real-time data collection and prediction, accurate supply of hydrogen-blended natural gas is achieved, and real-time verification is performed through the digital twin module 1 to ensure the safety and stability of the pipeline network and avoid safety risks caused by excessive hydrogen blending.

[0125] The detection module 5 collects the data of the terminal user's flow, temperature, date and so on in real time through sensors such as thermometers and flow meters, and transmits it to the usage prediction module 11; the usage prediction module 11 pre-processes the input data, removes noise through exponential weighted moving average (EWMA) filtering, and uses the gated recurrent unit network (GRU-Multi Head Attention) to predict the time series data of multi-dimensional features and output the hourly prediction results of hydrogen-blended natural gas consumption; according to the prediction results, the real-time hydrogen demand is sent to the PEM water electrolysis hydrogen production module 12 for preparation, and it is linked with the hydrogen storage tank 8 at the same time. When the hydrogen preparation is insufficient, the hydrogen storage tank 8 is automatically called to replenish it, and when the preparation is excessive, the excess hydrogen is stored; the digital twin module 1 collects the pipeline information of the terminal user, inputs the initial parameters of the pipeline network, updates the flow, pressure and temperature data in real time, establishes the pipeline network simulation model and sets the pressure and temperature values, and verifies the operation safety of hydrogen-blended natural gas through simulation; if the safety conditions are met, the digital twin module issues a blending instruction and starts the hydrogen blending skid module 6 to accurately blend hydrogen and natural gas; through real-time data transmission and linkage control between the modules, a full-process intelligent collaboration from data collection, consumption prediction, blending control, hydrogen replenishment to pipeline network safety verification is formed to ensure the accurate supply of hydrogen-blended natural gas and the safe and stable operation of the pipeline network.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A linkage method for the safety verification and real-time prediction linkage system of a hydrogen-blended natural gas pipeline network, characterized in that: The linkage method comprises the following steps: S1, the detection module (5) collects basic parameter data of the pipe network of the terminal user (2) through the thermometer (3) and the flow meter (4), the basic parameter data of the pipe network collected by the thermometer (3) is transmitted to the digital twin module (1), and the basic parameter data of the pipe network collected by the flow meter (4) is transmitted to the usage prediction module (11); S2, the digital twin module (1) collects the pipeline network information of the end user (2) and constructs a dynamic simulation model of the pipeline network; verifies the feasibility of safe operation and dynamically adjusts the hydrogen blending ratio; S3, the hydrogen blending ratio calculated by the digital twin module (1) is input into the usage prediction module (11) for data preprocessing; S4, according to the prediction processing result of the usage prediction module (11), the demand for hydrogen is calculated and determined, and the demand for hydrogen is sent to the PEM water electrolysis hydrogen production module (12), the hydrogen generated by the PEM water electrolysis hydrogen production module (12) is transmitted to the hydrogen doping skid module (6) through valve B (9), when the amount of hydrogen generated by the PEM water electrolysis hydrogen production module (12) is insufficient, the hydrogen storage tank (8) replenishes hydrogen from the hydrogen doping skid module (6) through valve A (7), and when the amount of hydrogen generated is greater than the demand, the PEM water electrolysis hydrogen production module (12) stores the excess hydrogen in the hydrogen storage tank (8) through valve C (10); In step S4, the calculation determines the demand for hydrogen as follows: (five) In formula (5), The actual hydrogen delivery volume for the hydrogen blending skid; The hydrogen demand in the hydrogen dosing skid module; is the available amount of hydrogen in the hydrogen storage tank; is the balance coefficient; (six) In formula (6), is the final determined hydrogen blending ratio; The node load demand for hydrogen-blended natural gas; is the natural gas node load demand; The formula is derived from the density ratio of natural gas and hydrogen as follows: (seven) In formula (VII), is the hydrogen demand fed back to the hydrogen blending skid; α is the gain parameter for hydrogen blending ratio control; β is the gain parameter for load prediction weight; is the current pressure of the natural gas system; The linkage system comprises a digital twin module (1), a detection module (5), a hydrogen doping skid module (6) and a usage prediction module (11); The detection module (5) comprises a terminal user (2), a thermometer (3) and a flow meter (4), wherein the thermometer (3) is used to collect temperature data of the terminal user (2), and the temperature data is transmitted to the digital twin module (1); and the flow meter (4) is used to collect load data of the terminal user (2), and the load data is transmitted to the usage prediction module (11); The usage prediction module (11) predicts the user's hourly usage of hydrogen-blended natural gas in real time based on the data collected by the detection module (5); The hydrogen blending skid module (6) controls the mixing ratio of hydrogen and natural gas according to the prediction result of the usage prediction module (11); The digital twin module (1) verifies the feasibility of safe operation and dynamically adjusts the hydrogen blending ratio by calculating the physical property parameters of hydrogen-blended natural gas; The calculation of the physical property parameters of hydrogen-blended natural gas includes density calculation, high calorific value calculation, and load conversion calculation; The density is calculated as follows: (one) In formula (1), is the density of natural gas after mixing with hydrogen; is the hydrogen incorporation ratio; is the density of natural gas; is the density of hydrogen; The high calorific value is calculated as follows: (two) In formula (2), The high calorific value of hydrogen-blended natural gas; It is the high calorific value of natural gas; It is the high calorific value of hydrogen; The load conversion calculation is as follows: (three) In formula (3), is the node load of hydrogen-blended natural gas; is the node load of natural gas.

2. The linkage method of the hydrogen-blended natural gas pipeline network safety verification and real-time prediction linkage system according to claim 1, characterized in that: The dynamic adjustment of hydrogen blending ratio is as follows: (Four) In formula (IV), is the final hydrogen blending ratio; is the maximum pressure deviation; is the maximum temperature deviation; is the actual pressure error; is the actual temperature error; is the maximum hydrogen doping ratio.

3. The linkage method of the hydrogen-blended natural gas pipeline network safety verification and real-time prediction linkage system according to claim 1, characterized in that: The system further comprises a valve A (7), a hydrogen storage tank (8), a valve B (9), a valve C (10) and a PEM water electrolysis hydrogen production module (12); The PEM water electrolysis hydrogen production module (12) and the hydrogen storage tank (8) are dynamically linked according to the demand for hydrogen to ensure the supply of hydrogen. The hydrogen storage tank (8) is used to replenish the hydrogen through the hydrogen storage tank (8) when the hydrogen production is insufficient, and to store the hydrogen in the hydrogen storage tank (8) when the hydrogen production is excessive. The PEM water electrolysis hydrogen production module (12) delivers hydrogen to the hydrogen doping skid module (6) through valve B (9); the PEM water electrolysis hydrogen production module (12) delivers hydrogen to the hydrogen storage tank (8) through valve C (10), and the hydrogen storage tank (8) delivers hydrogen to the hydrogen doping skid module (6) through valve A (7).

Images