A Method for Constructing a Risk Monitoring and Early Warning Tool for On-vehicle Hydrogen Systems of Fuel Cells

Abstract

The present invention relates to a method for constructing a risk monitoring and early warning tool for hydrogen systems on fuel cell vehicles. The method comprises the following steps: constructing a fuel cell vehicle hydrogen system equipment database and a hydrogen leakage database; processing the equipment database using a minimum cut set algorithm to obtain a first risk assessment result; performing a physical analysis of the hydrogen leakage database to obtain a second risk assessment result; and comprehensively processing the first and second risk assessment results and displaying them. This method can monitor and warn of vehicle hydrogen system risks, provide guidance for the safety management of hydrogen fuel cell vehicles, and promote the development and widespread application of hydrogen fuel cell technology.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen energy safety analysis, and more specifically, to a method for constructing a risk monitoring and early warning tool for a fuel cell vehicle-mounted hydrogen system. Background Art

[0002] The use of hydrogen energy has received significant attention from governments, automotive companies, energy companies, and environmental organizations worldwide. As one of the key applications of hydrogen energy, hydrogen fuel cell vehicles utilize proton exchange membrane fuel cells to convert the chemical energy of hydrogen into electrical energy. Due to their pollution-free, high-efficiency, and zero-emission advantages, they are gradually entering commercialization both domestically and internationally.

[0003] Based on domestic and international experience, the safety issue of hydrogen energy has become a bottleneck affecting its large-scale utilization. Hydrogen is flammable and explosive, has a wide combustion range (4% to 75%), has low ignition energy, a large diffusion coefficient, and is prone to embrittlement of the mechanical properties of materials. It has potential leakage and explosion hazards during preparation, storage, transportation, refueling, and use. Therefore, hydrogen safety is an important prerequisite for hydrogen energy application and large-scale commercial promotion. At the same time, economic efficiency is also a key factor in the large-scale utilization of hydrogen energy. If unilaterally improving safety indicators leads to a significant increase in hydrogen energy costs, it will reduce the market advantage of hydrogen energy and be detrimental to the development of the hydrogen energy industry. Therefore, it is necessary to scientifically understand the dangers of hydrogen, rationally formulate safety countermeasures for the hydrogen energy industry, strengthen relevant safety technology research and standard system construction, and thus support the healthy development of my country's hydrogen energy industry. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for constructing a risk monitoring and early warning tool for a hydrogen system on a fuel cell vehicle.

[0005] The technical solution adopted by the present invention to solve the technical problem is to construct a method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool, including the following steps:

[0006] Build a device database for fuel cell vehicle hydrogen systems and a hydrogen leakage database;

[0007] Processing the equipment database using a minimum cut set algorithm to obtain a first risk assessment result, and performing physical analysis on the hydrogen leakage database to obtain a second risk assessment result;

[0008] The first risk assessment result and the second risk assessment result are comprehensively processed and displayed.

[0009] Furthermore, in the method for constructing a fuel cell vehicle-mounted hydrogen system risk monitoring and early warning tool described in the present invention, in the process of constructing the hydrogen leakage database, a human-computer interaction interface is used to obtain the variable parameters required for the fuel combustion behavior, and the characteristic data of the fluid open source thermodynamics and transport properties required for the calculation are obtained from the CoolProp open source library.

[0010] Furthermore, in the method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to the present invention, the equipment database includes a risk frequency database of fuel cell vehicle hydrogen system leakage and an equipment reliability database of a fuel cell vehicle mitigation system; and the method of using a minimum cut set algorithm to process the equipment database to obtain a first risk assessment result includes:

[0011] Use fault trees to represent and calculate the probability of random leakage in the pipelines, joints, valves, and hydrogen storage cylinder seals of the fuel cell vehicle hydrogen system, as well as the probability of random failure of the decompression and isolation systems;

[0012] An event tree is used to analyze the accident scenario chain of jet fire or delayed ignition and explosion after hydrogen leakage, as well as the impact of safety protection system actions. A fault tree is used to conduct a systematic analysis of each mitigation system of the fuel cell vehicle.

[0013] After performing quantitative analysis on the event tree and the fault tree based on Boolean algebra operations and a binary decision diagram algorithm, a minimum cut set is obtained, and the minimum cut set is used as the first risk assessment result.

[0014] Furthermore, in the method for constructing a risk monitoring and early warning tool for a fuel cell vehicle hydrogen system according to the present invention, the minimum cut set risk construction process is as follows:

[0015] Cutset data acquisition is divided into event trees, and multithreading uses Kryo deserialization to obtain cutset data;

[0016] The affected cut set is screened by determining whether the basic events of the cut set include operating settings, unavailable settings, and basic events after considering common causes.

[0017] If the basic event of the cut set includes the basic event of running the standby, the hydrogen combustion frequency of the cut set is set to 0, and the hydrogen combustion frequency is accumulated;

[0018] When calculation is not available, a hash table is obtained by exhaustively searching each combination of several basic events;

[0019] The calculated affected cut sets absorb each other.

[0020] Furthermore, in the method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to the present invention, the physical analysis of the hydrogen leakage database to obtain a second risk assessment result includes:

[0021] The absolute pressure of the environment p0 and the critical pressure of hydrogen at the leak port p e The ratio is

[0022]

[0023] k is the hydrogen adiabatic index;

[0024] when When , hydrogen flows at a subsonic speed at the leakage port, and the leakage intensity of hydrogen is:

[0025]

[0026] when When , hydrogen flows at the speed of sound at the leak port, and the leakage intensity of hydrogen is:

[0027]

[0028] Where β is the critical pressure ratio; p1 is the hydrogen pressure in the pipeline; q m is the leakage flow; C a is the hydrogen leakage coefficient; Z is the hydrogen compressibility factor; M is the molar mass of hydrogen; R is the gas constant.

[0029] Furthermore, in the method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to the present invention, the physical analysis of the hydrogen leakage database to obtain a second risk assessment result includes:

[0030] Thermal radiation flux of the point heat source formed by the leakage crack:

[0031] q=μQ0H c

[0032] Where q is the thermal radiation flux of the point heat source; μ is the efficiency factor; Q0 is the leakage velocity, H c For the heat of combustion;

[0033] Calculation of thermal radiation intensity at a point:

[0034]

[0035] Where I i is the thermal radiation intensity of the point heat source i at the target x, q is the thermal radiation flux of the point heat source, R a is the thermal emissivity; x is the distance from the point heat source to the target point.

[0036] Furthermore, in the method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to the present invention, the physical analysis of the hydrogen leakage database to obtain a second risk assessment result includes:

[0037] When hydrogen undergoes a physical explosion, the explosive energy released is calculated by the following formula:

[0038]

[0039] Where: E g is the explosion energy of the gas; p is the absolute pressure of the gas; V is the volume of the container; k is the adiabatic index of the gas.

[0040] Furthermore, in the method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to the present invention, the physical analysis of the hydrogen leakage database to obtain a second risk assessment result includes:

[0041] Plume analysis: Calculate the plume-related data formed when different fuel forms are ejected from the nozzle under different nozzle models;

[0042] Fuel accumulation behavior analysis: Calculates the overpressure and cumulative behavior data generated by hydrogen ejected from different nozzle models, and outputs combustion chamber pressure diagrams, combustible mass diagrams, fuel stratification diagrams, fuel trajectory diagrams, and fuel mass flow rate diagrams;

[0043] Hydrogen flame temperature and trajectory behavior analysis: Calculate the flame temperature and trajectory data generated by different hydrogen fluid forms during injection combustion under different nozzle models, and output the flame cross-section diagram produced during simulated fuel combustion;

[0044] Fuel flame heat flux analysis: Calculates the behavior of the ignited flame under different fuel fluid forms and different nozzle models, including flame temperature, direction, and heat flux. Outputs thermal radiation data charts, heat flux distribution diagrams, and flame temperature cross-sections at different locations in a 3D perspective.

[0045] Overpressure Analysis: Calculates the overpressure and pulse pressure behavior of specified locations under different fuel fluid forms and nozzle models after fuel injection and ignition. Outputs overpressure and pulse pressure data charts in different dimensions after 3D modeling.

[0046] Furthermore, in the method for constructing a risk monitoring and early warning tool for a fuel cell vehicle hydrogen system described in the present invention, the first risk assessment result and the second risk assessment result include: accident physical evaluation, flame temperature and trajectory icons, flame heat flux charts, flame plume calculation charts, probabilistic safety assessments, accident sequence scenarios and probabilistic risk insights.

[0047] Furthermore, in the method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to the present invention, the comprehensive processing of the first risk assessment result and the second risk assessment result and displaying them includes:

[0048] Performing comprehensive analysis and visualization on the first risk assessment result and the second risk assessment result through a chart analysis library, and displaying the obtained chart file; and / or

[0049] The chart file is stored.

[0050] The implementation of the method for constructing a fuel cell vehicle-mounted hydrogen system risk monitoring and early warning tool of the present invention has the following beneficial effects: the present invention can monitor and warn of vehicle-mounted hydrogen system risks, provide guidance for the safety management of hydrogen fuel cell vehicles, and promote the development and popularization of hydrogen fuel cell technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0052] Figure 1 This is a flow chart of a method for constructing a risk monitoring and early warning tool for a fuel cell vehicle hydrogen system according to an embodiment of the present invention;

[0053] Figure 2 This is a flowchart of a fuel cell vehicle system safety analysis model study based on probability theory provided by an embodiment of the present invention;

[0054] Figure 3 This is a flowchart of the minimum cut set risk calculation engine construction provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0056] This embodiment studies a method for constructing a risk monitoring and early warning tool for fuel cell vehicle hydrogen systems based on a hydrogen energy numerical simulation model using event trees and fault trees, combined with probability theory and a hydrogen leakage physical analysis model. The main steps include the following:

[0057] The main technical method of this embodiment can be divided into 5 steps, as shown in the attached figure. Figure 1 shown.

[0058] 1.1 Construction of a safety analysis model for fuel cell vehicle systems based on probability theory

[0059] The research flow chart of fuel cell vehicle system safety analysis model based on probability theory is shown in the attached figure. Figure 2 shown.

[0060] 1.1.1 Construction of Fuel Cell Vehicle Hydrogen System Equipment Database

[0061] 1) Risk identification and analysis of leakage and accident mitigation of hydrogen systems on fuel cell vehicles;

[0062] 2) Build a risk frequency database for leakage of hydrogen systems on fuel cell vehicles;

[0063] 3) Build an equipment reliability database for the mitigation system;

[0064] 1.1.2 Analysis and modeling of initiating events

[0065] For random leakage events in the hydrogen system onboard a fuel cell vehicle, this embodiment uses a fault tree to represent and calculate the random leakage that occurs at the seals of pipelines, joints, valves, and hydrogen storage cylinders, as well as the failure of the pressure reducing valve, which causes high-pressure gas to directly enter the low-pressure pipeline and cause leakage. The frequency of occurrence of each basic event is calculated by multiplying the number of pipelines, valves, and joints between pipelines by the unit value of each leak size, and then modeled in the form of a fault tree. For random failures of the pressure reducing and isolation system, the probability of failure of the pressure reducing and isolation system is calculated using a fault tree, and the probability of high-pressure gas directly entering the low-pressure pipeline and causing the pipeline to rupture due to overpressure is calculated.

[0066] 1.1.3 Hydrogen Leakage Event Scenario Analysis and Probabilistic Safety Assessment (PSA) Analysis

[0067] An event tree analysis was used to analyze the accident scenario chain leading to jet fire or delayed ignition and explosion after a hydrogen leak, as well as the impact of safety protection system activation. A fault tree analysis was conducted on various mitigation systems, such as the instrumentation and control system, emergency shutoff system, pressure relief system, and fire protection system. After completing the system analysis and event tree analysis, probabilistic safety analysis modeling was carried out.

[0068] 1.1.4 PSA Quantification and Minimal Cut Set

[0069] The probabilistic safety analysis model is quantitatively analyzed based on Boolean algebra operations and binary decision diagram algorithms to obtain the minimum cut set.

[0070] 1.2 Construction of hydrogen leakage physical analysis model

[0071] The construction of the hydrogen leakage physical analysis model mainly includes the following technical contents:

[0072] 1) Calculate the probability of hydrogen ignition by leakage flow;

[0073] The probability of ignition after a hydrogen leak is related to the leak flow rate. The most common calculation of gas leak flow rate is derived from the Bernoulli equation, which is related to the flow state of the gas leaking from the orifice. Therefore, to determine whether the gas flow during a leak is sonic critical flow or subsonic critical flow, the critical pressure ratio can be used to determine:

[0074]

[0075] Where:

[0076] p0: ambient absolute pressure, in Pa;

[0077] p e : The critical pressure of hydrogen at the leak port, in Pa;

[0078] k: Hydrogen adiabatic index. The hydrogen adiabatic index k is a function of temperature and can be approximated as a constant for ideal gases. Alternatively, it can be set to 1.4 for diatomic gases, 1.29 for polyatomic gases, and 1.6 for monatomic gases.

[0079] when When , hydrogen flows at a subsonic speed at the leakage port, and the leakage intensity of hydrogen is:

[0080]

[0081] when When , hydrogen flows at the speed of sound at the leak port, and the leakage intensity of hydrogen is:

[0082]

[0083] Where:

[0084] β: critical pressure ratio;

[0085] p1: The pressure of hydrogen in the pipeline, in Pa;

[0086] q m : Leakage flow, unit is kg / s;

[0087] C a : Hydrogen leakage coefficient. The gas leakage coefficient is related to the shape of the leakage port. When the leakage port is circular, it is 1; when it is triangular, it is 0.95; when it is rectangular, it is 0.90; the gradually shrinking hole formed by internal corrosion takes 0.9 to 1.0; the gradually expanding hole formed by external corrosion or external force impact takes 0.6 to 0.9.

[0088] Z: hydrogen compression factor, here it is 1;

[0089] M: molar mass of hydrogen, in kg / mol;

[0090] R: Gas constant R is taken as 8.314 J / (mol·k);

[0091] 2) Calculation of thermal radiation flux and thermal radiation intensity

[0092] When pressurized combustible material leaks, it forms a jet. If ignited at the leaking breach, it forms a jet fire. The method for calculating the radiant heat of a jet fire extends the jet diffusion model to include airflow effects. The entire jet fire is considered to be composed of all point heat sources along the jet centerline, with each point heat source having an equal heat radiation flux.

[0093] Thermal radiation flux of a point heat source:

[0094] q=μQ0H c

[0095] Where: q is the thermal radiation flux of the point heat source; μ is the efficiency factor, which is 0.35; Q0 is the leakage rate, in kg / s, H c is the heat of combustion, in J / kg.

[0096] Calculation of thermal radiation intensity at a point:

[0097]

[0098] Where I i is the thermal radiation intensity of point heat source i at target x, in W / m 2 , q is the thermal radiation flux of the point heat source, R a is the thermal emissivity, which is taken as 0.2; x is the distance from the point heat source to the target point, in m (meter).

[0099] By calculating with the above formula, we can approximately determine the scope affected by the fire.

[0100] 3) Explosion overpressure calculation

[0101] When hydrogen undergoes a physical explosion, the explosive energy released is calculated by the following formula:

[0102]

[0103] Where: E g is the explosion energy of the gas, in kJ; p is the absolute pressure of the gas, in MPa; V is the volume of the container, in m 3 ; k is the adiabatic index of the gas.

[0104] The explosive equivalent is converted to TNT equivalent (qTNT). The explosive energy released by 1kg of TNT is 4230-4836 kJ / kg, with an average energy of 4500 kJ / kg generally taken. This formula quantitatively reflects the degree of damage caused by an explosion within a certain range.

[0105] 1.3 Construction of Minimum Cut Set Risk Calculation Engine

[0106] Based on the initiating event analysis and modeling in Section 1.1, Risk Spectrum software was used to perform a cut set algorithm analysis to obtain the minimum cut set set for the fuel cell vehicle hydrogen system. The minimum cut set algorithm was used to build the calculation engine. The main considerations are as follows: Figure 3 As shown:

[0107] 1) Cutset data acquisition is divided according to the event tree, and multi-threaded Kryo deserialization is used to obtain the cutset data;

[0108] 2) The affected cut set is screened by determining whether the basic events of the cut set include operating settings, unavailable settings, and basic events after considering common causes;

[0109] 3) Running standby calculation: If the basic events of the cut set include the basic events of running standby, the cut set HCF is set to 0 and HCF is accumulated; where HCF is the hydrogen combustion frequency, that is, the frequency of hydrogen combustion.

[0110] 4) When calculation is not available, a hash table is obtained by exhaustively searching for each combination of several basic events;

[0111] 5) Internal absorption: The calculated affected cut sets absorb each other (combined hash table optimization performance)

[0112] 1.4 Physical analysis and evaluation after hydrogen leakage

[0113] This example conducts hydrogen leakage post-combustion simulation calculation and characteristic evaluation from five dimensions:

[0114] 1) Plume analysis: Calculate the plume-related data formed when different fuel forms are ejected from the nozzle under different nozzle models.

[0115] 2) Fuel Cumulative Behavior Analysis: Calculates the overpressure and cumulative behavior data generated by hydrogen ejected from different nozzle models, and outputs combustion chamber pressure diagrams, combustible mass diagrams, fuel stratification diagrams, fuel trajectory diagrams, and fuel mass flow rate diagrams.

[0116] 3) Hydrogen flame temperature and trajectory behavior analysis: Calculate the flame temperature and trajectory data generated by different hydrogen fluid forms during injection combustion under different nozzle models, and output the flame cross-section diagram produced during simulated fuel combustion.

[0117] 4) Fuel flame heat flux analysis mainly calculates the behavior of the jet flame after ignition under different fuel fluid forms and different nozzle models, including flame temperature, direction, and heat flux. It outputs thermal radiation data charts, heat flux distribution diagrams, and flame temperature cross-section diagrams at different positions in a three-dimensional perspective.

[0118] 5) Overpressure analysis: This function calculates the overpressure (unrestricted) and pulse pressure behavior at specified locations under a 3D modeling perspective after fuel injection and ignition for different fuel fluid forms under different nozzle models. The function then outputs overpressure and pulse pressure data charts for different dimensions after 3D modeling.

[0119] 1.5 Risk Assessment and Display

[0120] 1) A combustion analysis and calculation engine for alternative hydrogen fuels written in Python, with the front-end user interface providing the variable parameters required for fuel combustion behavior.

[0121] 2) Obtain the characteristic data of fluid open source thermodynamics and transport properties required for calculation (temperature, density, mass and other characteristic parameters required for calculation) through the CoolProp open source library widely used in the industry

[0122] 3) After the calculation engine completes the calculation, the calculation results are visualized through the chart analysis library and output as chart files. In addition, the data is persistently stored.

[0123] 4) After the user fills in the parameters for calculating a specific dimension through the interactive interface, the calculation and analysis engine is called to output the characteristic data of the flame jet or explosion scene, and generate graphic charts and two-dimensional data tables of the corresponding dimensions.

[0124] 5) The generation of visual graphics and charts is primarily accomplished by the computational analysis engine, leveraging the powerful Python-based Matplotlib visualization library. This engine supports the generation of a variety of complex commercial charts, meeting the output requirements of the graphics and charts described in this patent.

[0125] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0126] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0127] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0128] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the present invention and implement it accordingly. They are not intended to limit the scope of protection of the present invention. All equivalent variations and modifications within the scope of the claims of the present invention are intended to be covered by the claims of the present invention.

Claims

1. A method for constructing a risk monitoring and early warning tool for a fuel cell vehicle-mounted hydrogen system, characterized in that: The steps include: Build a device database for fuel cell vehicle hydrogen systems and a hydrogen leakage database; Processing the equipment database using a minimum cut set algorithm to obtain a first risk assessment result, and performing physical analysis on the hydrogen leakage database to obtain a second risk assessment result; Comprehensively processing the first risk assessment result and the second risk assessment result and displaying them; The equipment database includes a risk frequency database of leakage of the fuel cell vehicle hydrogen system and an equipment reliability database of the fuel cell vehicle mitigation system; The using of the minimum cut set algorithm to process the equipment database to obtain a first risk assessment result includes: Use fault trees to represent and calculate the probability of random leakage in the pipelines, joints, valves, and hydrogen storage cylinder seals of the fuel cell vehicle hydrogen system, as well as the probability of random failure of the decompression and isolation systems; An event tree is used to analyze the accident scenario chain of jet fire or delayed ignition and explosion after hydrogen leakage, as well as the impact of safety protection system actions. A fault tree is used to conduct a systematic analysis of each mitigation system of the fuel cell vehicle. After performing quantitative analysis on the event tree and the fault tree based on Boolean algebra operations and a binary decision diagram algorithm, a minimum cut set is obtained, and the minimum cut set is used as the first risk assessment result; The minimum cut set risk construction process is: Cutset data acquisition is divided into event trees, and multithreading uses Kryo deserialization to obtain cutset data; The affected cut set is screened by determining whether the basic events of the cut set include operating settings, unavailable settings, and basic events after considering common causes. If the basic event of the cut set includes the basic event of running the standby, the hydrogen combustion frequency of the cut set is set to 0, and the hydrogen combustion frequency is accumulated; When calculation is not available, a hash table is obtained by exhaustively searching each combination of several basic events; The calculated affected cut sets absorb each other.

2. The method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to claim 1, characterized in that: In the process of constructing the hydrogen leakage database, the variable parameters required for fuel combustion behavior are obtained using a human-computer interaction interface, and the characteristic data of fluid open source thermodynamics and transport properties required for calculation are obtained from the CoolProp open source library.

3. The method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to claim 1, characterized in that: The second risk assessment result obtained by performing a physical analysis on the hydrogen leakage database includes: Ambient absolute pressure and the critical pressure of hydrogen at the leak The ratio is is the hydrogen adiabatic index; when When , hydrogen flows at a subsonic speed at the leakage port, and the leakage intensity of hydrogen is: when When , hydrogen flows at the speed of sound at the leak port, and the leakage intensity of hydrogen is: In the formula is the critical pressure ratio; p1 is the pressure of hydrogen in the pipeline; is the leakage flow; is the hydrogen leakage coefficient; is the hydrogen compressibility factor; M is the molar mass of hydrogen; R is the gas constant.

4. The method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to claim 1, characterized in that: The second risk assessment result obtained by performing a physical analysis on the hydrogen leakage database includes: Thermal radiation flux of the point heat source formed by the leakage crack: In the formula is the thermal radiation flux of the point heat source; is the efficiency factor; is the leakage rate, For the heat of combustion; Calculation of thermal radiation intensity at a point: In the formula is the thermal radiation intensity of point heat source i at target x, is the thermal radiation flux of the point heat source, is the thermal emissivity; x is the distance from the point heat source to the target point.

5. The method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to claim 1, characterized in that: The second risk assessment result obtained by performing a physical analysis on the hydrogen leakage database includes: When hydrogen undergoes a physical explosion, the explosive energy released is calculated by the following formula: Where: is the explosion energy of the gas; is the absolute pressure of the gas; V is the volume of the container; is the adiabatic index of the gas.

6. The method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to claim 1, characterized in that: The second risk assessment result obtained by performing a physical analysis on the hydrogen leakage database includes: Plume analysis: Calculate the plume-related data formed when different fuel forms are ejected from the nozzle under different nozzle models; Fuel accumulation behavior analysis: Calculates the overpressure and cumulative behavior data generated by hydrogen ejected from different nozzle models, and outputs combustion chamber pressure diagrams, combustible mass diagrams, fuel stratification diagrams, fuel trajectory diagrams, and fuel mass flow rate diagrams; Hydrogen flame temperature and trajectory behavior analysis: Calculate the flame temperature and trajectory data generated by different hydrogen fluid forms during injection combustion under different nozzle models, and output the flame cross-section diagram produced during simulated fuel combustion; Fuel flame heat flux analysis: Calculates the behavior of the ignited flame under different fuel fluid forms and different nozzle models, including flame temperature, direction, and heat flux. Outputs thermal radiation data charts, heat flux distribution diagrams, and flame temperature cross-sections at different locations in a 3D perspective. Overpressure Analysis: Calculates the overpressure and pulse pressure behavior of specified locations under different fuel fluid forms and nozzle models after fuel injection and ignition. Outputs overpressure and pulse pressure data charts in different dimensions after 3D modeling.

7. The method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to claim 1, characterized in that: The first risk assessment results and the second risk assessment results include: accident physics evaluation, flame temperature and trajectory chart, flame heat flux chart, flame plume calculation chart, probabilistic safety evaluation, accident sequence scenario and probabilistic risk insights.

8. The method for constructing a fuel cell vehicle hydrogen system risk monitoring and early warning tool according to claim 1, characterized in that: The comprehensive processing of the first risk assessment result and the second risk assessment result and displaying the results includes: Performing comprehensive analysis and visualization on the first risk assessment result and the second risk assessment result through a chart analysis library, and displaying the obtained chart file; and / or The chart file is stored.

Images