Fire-fighting effect evaluation method under digital modeling

Abstract

The application discloses a fire-fighting effect evaluation method under digital modeling, and relates to the technical field of fire-fighting evaluation and public safety management. In a fire-fighting layout digital model, a parallel simulation calculation task is established for each preset fire scene, a dynamic fire development thermodynamic equation and a smoke diffusion calculation model are introduced, a flame heat spreading and diffusion process, a three-dimensional diffusion process of toxic smoke, an automatic starting response process of fire-fighting facilities after reaching a threshold value and an escape and evacuation process of people in a building are independently simulated under multi-level fire conditions, and dynamic simulation characteristic data under each fire scene is batch output. The application constructs a set of physical level general and interactive digital modeling and simulation framework. By introducing a bottom fluid partial differential equation and a thermodynamic model, the application can seamlessly adapt to modern buildings of any heterogeneous structure and complex floor without the need of developing a special model for each evaluation task.

Description

Technical Field

[0001] This invention relates to the field of fire protection assessment and public safety management technology, specifically a method for fire protection effectiveness assessment based on digital modeling. Background Technology

[0002] With the accelerated pace of urbanization, modern buildings are constantly expanding in scale, significantly increasing in structural complexity, and continuously enhancing in functional diversity. For example, a large number of complex buildings such as large commercial complexes, super high-rise office buildings, underground transportation hubs, and large medical centers are emerging. These complex buildings have large spatial spans, dense populations, high mobility, and interwoven internal functional zones. Once a fire occurs, it will bring great risks of casualties and property damage. Therefore, quantitatively assessing the actual operational effectiveness of the fire protection system in complex buildings in advance is a core requirement in current fire management, emergency acceptance, and public safety prevention.

[0003] However, existing fire assessment technologies have significant limitations in practical applications: traditional assessment methods rely heavily on static compliance checks or expert judgment, often ignoring real physical factors such as irregular spatial layouts, complex ventilation and air conditioning systems, and the diversity of mixed flammable building materials in complex buildings during actual operation. This leads to assessment results that are too idealistic and fail to truly reflect the dynamic evolution of a fire. At the same time, existing computer simulation fire protection technologies are mostly customized solutions developed for specific extreme scenarios. These systems are closed and lack universality, making them unsuitable for the daily assessment needs of general complex buildings.

[0004] As a prior art document for this application, Chinese Patent Publication No. CN121351377A proposes an "Aircraft Fire Simulation and Firefighting and Rescue Assessment System". This technical solution is designed for the extremely specific scenario of the enclosed cabin of an aircraft. It has developed a highly customized calculation model for fire spread and firefighting efficiency to simulate rescue plans after an aircraft fire. However, analyzing the principle of this prior art, it has a core defect that cannot be adapted to general fire management needs: First, the scenario of this solution is completely customized. Its underlying theoretical model has been specially modified for aviation materials and the unique enclosed structure of aircraft cabins. It cannot be transferred to the assessment of open, semi-open and multi-story large space structures of complex urban buildings. The scenario adaptability is seriously lacking. Secondly, the assessment phase of this plan is misaligned. Its technical approach focuses only on the tactical simulation of post-disaster relief effects and cannot achieve quantitative verification of the effectiveness of pre-disaster fire protection configuration before building construction and fire protection system deployment. Finally, its assessment dimensions are extremely one-sided, only conducting isolated simulations of a single fire scenario, which cannot cover the multi-level and full-grade fire risks faced by complex urban buildings, resulting in assessment results lacking reference value from a global perspective.

[0005] In summary, existing technologies generally suffer from common problems that urgently need to be addressed, such as a lack of scenario adaptability, misalignment of assessment stages, and one-sided assessment dimensions. These issues make it difficult to meet the practical needs of modern urban public safety and emergency management at both the macro-decision-making and pre-emptive prevention levels. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a general fire protection effectiveness evaluation method that covers all levels of pre-emptive risk verification and is adapted to the needs of public safety management decision-making, in order to address the shortcomings of existing technologies such as poor scenario adaptability, lack of universality, evaluation stage limited to the post-event stage and inability to verify in advance, and one-sided evaluation dimensions caused by single scenario simulation. This method enables a comprehensive and efficient quantitative evaluation of fire protection systems in various complex buildings.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A method for evaluating fire protection effectiveness using digital modeling includes the following steps: The first step is to collect structural information of the target building: by combining the import and analysis of building information model with multi-dimensional laser scanning, the full three-dimensional structural information of the target building is obtained. The full three-dimensional structural information includes the three-dimensional spatial layout of each floor, the dimensions of the interior space, the parameters of the ventilation duct network, the combustion properties of building materials in each zone, and the topological data of the internal evacuation passages. The second step is 3D digital modeling of the building: Based on the collected 3D structural information, the 3D mesh space is discretized to construct a high-precision 3D digital model of the target building, which restores the core features of the target building from the physical dimension, such as the spatial structural characteristics, aerodynamic ventilation logic, and material heat conduction and combustion properties. The third step is to input fire protection configuration data: provide a standardized data interaction interface to obtain the proposed or existing fire protection configuration data of the target building. The fire protection configuration data includes, but is not limited to, the spatial coordinates, hardware models, response time parameters, and hydraulic or wind performance parameters of various fire protection facilities such as automatic sprinkler systems, indoor and outdoor fire hydrant systems, mechanical smoke exhaust and positive pressure ventilation systems, and automatic fire alarm systems. The fourth step is fire protection layout model fitting: the input fire protection configuration data is mapped and fitted to the high-precision three-dimensional digital model through a spatial coordinate registration algorithm to generate an integrated fire protection layout digital model. By restoring the spatial distribution network of fire protection facilities, the linkage response logic between facilities, and the characteristics of fire extinguishing and smoke exhaust intervention capabilities in virtual space, the virtual integration of physical building and fire protection facility configuration scheme is realized. Furthermore, it supports interactive and dynamic adjustment of the above configuration parameters and positions through an interactive interface; Step 5, Multi-level fire risk scenario pre-setting: Combining the risk statistics data in the emergency management system and the specific functional attributes of the target building, a multi-level fire scenario matrix covering all risk levels is pre-set, specifically including three risk levels: Level 1 scenario is defined as initial small fire, corresponding to initial fires induced by local electrical short circuits inside the building; A Level 2 scenario is defined as a fire in the development stage, corresponding to a medium-sized fire caused by localized dense combustibles that has already shown a tendency to spread; Level 3 scenario is defined as an extreme fire, which corresponds to an unfavorable extreme fire in which multiple floors or a large area of ​​mixed fuels catch fire simultaneously. Step 6, Multi-level scenario batch fire simulation: In the fire layout digital model, parallel simulation calculation tasks are established for each preset fire scenario. Dynamic fire development thermodynamic equation and smoke diffusion partial differential calculation model are introduced to independently simulate the flame heat spread and diffusion process, the three-dimensional diffusion process of toxic smoke, the automatic activation response process of each fire protection facility after reaching the threshold, and the escape and evacuation process of people inside the building according to the dynamic smoke distribution under multi-level fire conditions. Then, dynamic simulation characteristic data of each level of fire scenario are output in batches. Step 7, Quantitative evaluation of fire response: Based on the dynamic simulation feature data output by the multi-level scenario batch fire simulation, and relying on the indicators of the emergency management public safety system, a quantitative evaluation calculation system is constructed that includes four dimensions: equipment response timeliness, fire control capability, evacuation guarantee capability, and risk coverage capability. The sub-item scores of each dimension and the comprehensive evaluation quantitative score representing the overall effect of the system are calculated using a multi-dimensional weighted evaluation calculation model. Step 8: Output of evaluation results: The final quantitative evaluation results are output to the user through a visual interface. The results include individual fire protection efficiency indicators under different risk scenarios, quantitative scores of overall comprehensive fire protection effect, and configuration optimization suggestions for weak links, providing a scientific basis for fire protection acceptance, hazard investigation, emergency management resource allocation and management decisions.

[0008] In a further technical implementation, as an extension of the present invention compared to the prior art, the dynamic fire development thermodynamic equation and the smoke diffusion partial differential calculation model used in the sixth step are specifically derived physically through the following mathematical formulas: To characterize the increase in fire source power in multi-level fire scenarios, a dynamic quadratic growth model is used: ; In this formula, for The dynamic heat release rate of the fire source at any given moment; Fire growth coefficient to characterize the properties of different combustibles; This refers to the cumulative duration calculated from the start of the fire.

[0009] For flue gas diffusion calculations, a variant Gaussian three-dimensional diffusion equation is used to calculate the three-dimensional concentration distribution field of toxic fumes within the building space: ; In this formula, The real-time concentration of flue gas at a specific coordinate point in space at a specific time; This represents the total mass of smoke gas released cumulatively from the time the fire occurred until the calculated time. The overall smoke diffusion coefficient is affected by the building's internal ventilation and temperature difference. The relative diffusion time of smoke from the source of the fire to its spatial spread; The spatial three-dimensional coordinates of the nodes to be calculated inside the three-dimensional digital model of the building; To determine the three-dimensional center coordinates of the fire source.

[0010] For the escape and evacuation process of personnel in a dynamic disaster environment, a multivariate time-accumulation model is used for calculation: ; In this formula, The total evacuation time required for people in a specific area to escape to a safe zone; To identify the detection alarm time when a fire alarm detector reaches the response threshold; The response time for personnel to confirm and prepare for action after receiving an alarm; This is the actual optimal evacuation route length after avoiding the smoke hazard area; To take into account the actual movement speed of people after the reduction of population density.

[0011] As one of the core creative points of this invention, combined with the decision-making and management needs of public safety computing systems, the seventh step, "Quantitative Evaluation of Fire Response," includes a dynamic weighting system based on social public safety management attributes, and uses the following formula to complete the score calculation and overall evaluation for four dimensions: Calculate the device response timeliness score: ; In this formula, The score is used to evaluate the timeliness of equipment response. The response time penalty coefficient set for delayed startup; This is the calculation time for the actual triggering and activation of fire-fighting equipment in the virtual simulation; This is the maximum allowable start-up time for this equipment as specified in current fire protection regulations.

[0012] Calculate the fire control capability score: ; In this formula, The score reflects the fire control capability, which is used to assess the effectiveness of fire-fighting facilities in suppressing fire. This refers to the actual horizontal area of ​​combustion burns calculated at the end of the virtual simulation. The total horizontal area of ​​the independent fire compartment to which the fire originated; The critical temperature threshold that a building's main structure or materials can withstand without causing damage or collapse. This represents the highest actual environmental temperature detected and recorded within the fire scene during the simulation.

[0013] Calculate the evacuation support capability score: ; In this formula, Scoring is based on evacuation capabilities that ensure the safety of people's lives; The upper limit of available safe evacuation time that can be provided before the smoke layer in the built environment settles to a critical danger height; The definition and calculation method have been explained above.

[0014] Calculate the risk coverage score: ; In this formula, The overall score is used to assess the fire protection plan's ability to cover risks in different severe working conditions; The total number of risk scenario levels preset for this system (in this plan, this is the number of multi-level fire scenarios). For the first The mathematical weight coefficient of each level of risk scenario in the evaluation system; For the fire protection system in a single first The score is the overall performance of each item after timeliness, control, and evacuation calculations under a level-one risk scenario.

[0015] Calculate the overall fire protection effectiveness quantitative evaluation value: ; In this formula, This is the final quantitative comprehensive score for the building's fire protection configuration system; These represent the weighting of scores in the final management decision evaluation for four independent dimensions: equipment response timeliness, fire control capability, evacuation guarantee capability, and risk coverage capability.

[0016] These four weights are not fixed, but are automatically and dynamically adjusted by the system by importing the social attribute parameters of the target building (such as plot ratio, peak pedestrian flow, and industry category) to ensure that the sum of the weight ratios remains constant. .

[0017] Compared with the prior art, the beneficial effects of the present invention by adopting the above technical solution are as follows: 1. This invention constructs a physical-level universal and interactive digital modeling and simulation framework. By introducing underlying fluid partial differential equations and thermodynamic models, it can seamlessly adapt to modern buildings with arbitrary heterogeneous structures and complex floors. It does not require the redevelopment of a dedicated model for each assessment task, effectively breaking down the technical barriers between different application scenarios and significantly reducing the technical cost and development cycle of fire assessment operations. 2. This invention completely reverses the problem of the misalignment of time stages in the existing technology that focuses solely on the tactical simulation of post-disaster relief. By allowing users to directly and interactively input and fit preset fire protection system configuration data, it enables the protection capability of the configuration to be quantitatively predicted in a purely digital environment before the building is started or the fire protection facilities are modified, thus effectively playing a role in preventing problems before they occur. 3. This invention creatively proposes a "batch full-scale simulation mechanism for multi-level fire risk scenarios," which completely solves the one-sided drawbacks of single-severity simulation in existing technologies. The system can verify the accurate extinguishing capability of automatic alarm and sprinkler equipment under minor initial fires, as well as the smoke control and smoke extraction interception performance under fire development. Furthermore, it can verify the ability to guarantee the ultimate survival time for personnel escape when facing extreme and uncontrolled fires. The assessment covers more than 90% of known urban fire risks, avoiding missed detections in risk blind spots.

[0018] 4. This invention delves into the digital pain points of public safety emergency management, translating complex fluid mechanics and heat conduction physical quantities into a quantitative scoring system that management decision-makers can intuitively understand (i.e., equipment response timeliness, fire control capabilities, etc.). At the same time, it creatively introduces a calculation architecture that dynamically adjusts the evaluation weights based on the social attributes of buildings, truly transforming the originally vague concept of "whether the fire protection system is compliant" into a highly credible "quantitative score." This allows the evaluation output results to not only remain at the scientific and technical level, but also to be directly and seamlessly integrated into macro-management decision-making scenarios such as urban planning acceptance, insurance rate calculation, and fire protection resource allocation. Attached Figure Description

[0019] Figure 1 This is a flowchart of the overall method of the present invention. Figure 2 This is a logic diagram for simulating multi-level fire risk scenarios in this invention. Detailed Implementation

[0020] To make the technical objectives, implementation schemes, core inventive points and beneficial effects of the present invention clearer and more thorough, the following will provide a more detailed disclosure and explanation of the method claimed by the present invention in conjunction with specific and detailed engineering application embodiments. It should be understood that the specific embodiments described herein are only used to illustrate the general operating mechanism of the present invention through specific scenarios, and are not intended to limit the scope of application of the core concept of the present invention in any way.

[0021] Systems based on the method of this invention can be deployed on workstation clusters or cloud servers with high-performance graphics rendering and parallel matrix computing capabilities to support complex three-dimensional structure fitting and the solution of transient thermodynamic fluid differential equations.

[0022] Please see the appendix Figure 1 - Appendix Figure 2 This invention provides a method for evaluating fire protection effectiveness using digital modeling.

[0023] [Example 1: Quantitative fire safety assessment targeting a medium-sized urban commercial complex] The target evaluation object of this embodiment is a five-story large-scale comprehensive commercial building in the core business district of a city. It is a typical building with a high population density and complex functions. It has a total of five floors above ground and two underground parking levels. The total above-ground building area is as high as 52,000 square meters. Its internal functional spaces are intricate and complex. Within the same volume, it includes an open atrium, a large number of enclosed retail shops, a large catering kitchen area, and an enclosed large multiplex cinema on the top floor (5th floor). The existing preliminary fire protection configuration plan to be verified covers a comprehensive automatic sprinkler system, an indoor pipe network fire hydrant system, a mechanical smoke exhaust system driven by mechanical fans, and a linked automatic fire alarm detection system.

[0024] The specific implementation steps for verifying fire protection effectiveness using the method of this invention are as follows: Step 1: Structural Information Acquisition. The system first imports the original Building Information Model (BIM model) of the large commercial complex generated during the design phase through the cloud interface. The model adopts the standard IFC format. The backend parsing engine extracts all and core structural parameter information from the massive architectural design files. The information obtained includes, but is not limited to: the three-dimensional spatial dimensions of each floor accurate to the millimeter level, and the spatial layout coordinates of the walls and floors. Detailed routing of ventilation and air conditioning ducts, duct cross-sectional dimensions, and rated air volume parameters; Simultaneously, database comparison information of various regional partition walls and interior decoration materials is extracted to obtain combustion property data such as thermal conductivity and specific heat capacity of these materials. The key points are to extract and record the width of stairwells used for personnel evacuation, the width of safety exits, and the direction of each passage.

[0025] Step 2: 3D digital modeling of the building. The parsing program converts the building structure entities extracted in Step 1 into a 3D hexahedral mesh model for fluid dynamics and thermodynamics calculations. For key parts of the building space, such as the tiered seating area of ​​the 5th-floor cinema and the high-ceilinged atrium area, adaptive mesh densification technology is used to ensure that the physical characteristics of the space are restored without loss, and a "physical twin digital complex" is successfully replicated in the computer memory.

[0026] Step 3: Fire Protection Configuration Interactive Input. The assessment engineer inputs the detailed fire protection configuration data dictionary to be deployed in the complex through the system's graphical user interface. The specific data list is as follows: Automatic sprinkler system: A total of 1240 standard closed sprinkler heads are deployed, and the configuration shows that it has achieved coverage of all areas except the power distribution room. The system water supply response time is set to ≤30 seconds, and the designed continuous spray intensity is set to 8L / (min·m). 2 ); Indoor fire hydrant system: A total of 68 indoor fire hydrant boxes are distributed throughout the building. The straight-line distance between adjacent fire hydrants is set to ≤30 meters. The water pump supply pressure is designed to ensure that the water jet height of the fire hose is >13 meters. Mechanical smoke exhaust system: The building interior is divided into 24 independent smoke control and exhaust zones, and the design specification for the smoke exhaust volume of the rooftop smoke exhaust fans is set at ≥60m³. 3 / (h·m 2 ); Automatic fire alarm system: The system deploys a combination of photoelectric smoke and heat detectors throughout the area, and the control host command transmission and start-up response time parameters are set to ≤10 seconds.

[0027] Step 4: Fire protection layout model fitting. The system uses an embedded spatial location analysis algorithm to accurately overlay the thousands of virtual fire protection facilities configured above into the solid mesh model established in Step 2 using a relative three-dimensional coordinate mapping method, generating a digital twin model of the fire protection layout. This ensures that the routing of each fire water pipe avoids the building beams and conforms to gravity logic. In this step, if the assessor finds a blind spot in the radiation range of a certain fire hydrant, they can directly use the mouse to drag and adjust the position on the three-dimensional interface, and the underlying coordinate data and logical connections will be automatically refreshed instantly.

[0028] Step 5: Multi-level risk scenario pre-setting. To comprehensively test the reliability of the fire protection design, the system, based on the complex functional characteristics of the commercial complex, relies on the fire source power growth model disclosed in the invention. It automatically presets three test scenarios with progressively increasing severity: Level 1 Scenario (Initial Small Fire): The fire source is set to a closed retail clothing store on the first floor. The cause of the fire is determined to be a short circuit in the old electrical wiring inside. A fire growth factor is set. The power of the fire source is limited to 100kW to allow the fire to reach a stable combustion period. This scenario is used to examine the system's ability to detect and automatically intervene in and contain initial hidden fires.

[0029] Scenario 2 (Development Stage Fire): The fire source is set as the kitchen of a large catering area on the 3rd floor. It is assumed to be caused by overheated cooking oil. Due to the rapid combustion of oil and its easy spread through the exhaust ducts, a corresponding fire growth coefficient is set. The maximum output power of the fire source is set to 1200kW. This scenario focuses on examining the isolation and blocking effectiveness of the smoke control system and the manual fire extinguishing capability of the fire hydrants.

[0030] Level 3 Scenario (Extreme Major Fire): The most dangerous fire source is located in the cinema auditorium on the top floor (5th floor). Considering the presence of a large amount of highly flammable materials such as polyurethane soft-padded sound insulation materials and synthetic fiber seats inside the cinema, a corresponding fire growth coefficient is set. The coefficient causes the maximum output power of the fire source to surge to 5000kW. This scenario simulates the extreme evacuation and escape of personnel in the face of a large-scale extreme fire under the worst conditions.

[0031] Step 6: Multi-level scenario batch parallel simulation. The system calls on the cluster computing power to apply the dynamic thermal diffusion and flue gas diffusion equations (i.e., those containing...) to the three preset scenarios mentioned above. and Equations with variables and other parameters are used to perform full-process time-step calculations, and the process records are output in batches after background processing. For the Level 1 scenario: The simulation system shows that the alarm quickly reaches the trigger threshold after a small amount of smoke is produced by the fire. The automatic sprinkler system opens the valve and successfully sprays water 28 seconds after the fire starts. Since the fire is still weak, the system achieves complete fire control and cooling in 62 seconds. The fire area is firmly locked inside the shop where the fire started. Toxic smoke is extracted by the ventilation system before it can accumulate on a large scale. People are safely evacuated without any pressure.

[0032] For the Level 2 scenario: simulation calculations revealed that after the grease caught fire, the alarm system responded sensitively within 11 seconds, and the virtual mini fire station personnel completed their deployment using fire hydrants within 95 seconds.

[0033] The calculation engine showed that the fire was effectively contained within 180 seconds, preventing it from spreading to the outer restaurant area.

[0034] Using formula Detailed modeling and calculation of internal personnel evacuation behavior to determine the actual evacuation time. The time is 245 seconds, which is far shorter than the 360-second absolute safe evacuation time limit required by regulations, leaving ample safety margin.

[0035] For the Level 3 scenario: In extreme conditions, the automatic sprinklers in the high-ceilinged cinema space experience delayed activation due to the obstruction of hot airflow. Even after activation, the water supply is insufficient compared to the 5000kW heat source, making complete physical fire control impossible. However, system simulations show that thanks to the powerful independent smoke extraction system on the roof, the high-density toxic fumes are successfully suppressed to a height of over 2.2 meters above the ground. Due to the well-controlled smoke layer height, the safety of the breathing zone is ensured. The total evacuation time is calculated to be 320 seconds, which is less than the calculated safe evacuation time for the area. The 480-second time limit was successfully maintained, preventing mass casualties.

[0036] Step 7: Fire safety quantitative evaluation. Based on a scoring formula system based on management needs, the massive simulation results are mathematically normalized. Due to the high population density in commercial complexes, the system dynamically assigns evacuation and support capabilities. The highest evaluation weight.

[0037] The scores for each sub-indicator are as follows: Based on the response timeliness formula, no facilities were found to have exceeded the start-up time limit, and the equipment response timeliness score was [score missing]. It scored 92 points; Based on the fire control formula, the fire control performance was excellent in Level 1 and Level 2 scenarios (achieving 98 and 90 points respectively), but there was a fire out of control in Level 3 scenario (only 78 points). Therefore, the overall fire control capability score was calculated by weighting and equalizing the scores. It scored 89 points; All scenarios All are less than the corresponding Evacuation and support capabilities score Achieve a high score of 95; The system architecture did not collapse even when subjected to extreme to minor Level 3 risk tests, resulting in a high risk coverage score. It scored 92 points.

[0038] Comprehensive weighted substitution formula The final comprehensive fire protection effectiveness quantitative assessment score was 91 points.

[0039] Step 8: Visualize the results. The comprehensive evaluation of 91 points is displayed intuitively on a large screen. The system automatically generates a management decision report based on the shortcomings in the score and points out the conclusion: The current fire protection configuration is at an excellent level and responds well to daily emergencies.

[0040] However, since the 5-story cinema scored only 78 points in fire suppression under a high-power fire source (Level 3 scenario), which poses a potential hazard, the system provides specific configuration optimization suggestions: It is recommended to add local high-pressure fine water mist fire extinguishing devices or high-flow fire monitors behind the cinema screen and in concealed locations in the stairwells to enhance the instantaneous extinguishing and cooling capabilities for large-area extreme fires.

[0041] [Example 2: Quantitative Fire Safety Assessment of a Super High-Rise Complex Medical and Scientific Research Hub] To further demonstrate the versatility and management guidance value of this invention in dealing with buildings with more extreme and special public safety attributes (extremely high management requirements and evacuation difficulties), this embodiment selects a "high-rise medical center and scientific research complex" under planning and construction in a megacity as the evaluation object.

[0042] The target building is extremely large in scale and has special social management attributes. The total construction area reaches 120,000 square meters, with the main building above ground reaching 40 floors and 3 floors underground (connected to the adjacent subway transportation hub, resulting in an extremely complex underground wind pressure environment). In terms of functional structure, floors 1 to 10 above ground are for outpatient and emergency departments and high-precision medical equipment examination areas. Floors 11 to 25 are inpatient ward areas; The upper 26 floors house multiple research laboratories storing hazardous chemical reagents and biological agents; Refuge floors were also set up on the 15th and 30th floors.

[0043] Because the building houses a large number of critically ill patients with extremely slow mobility and wheelchair users, its social risk level under the emergency management system is set to the highest level.

[0044] The specific implementation steps are explained below: Steps 1 and 2: Building digital twin construction. Using multi-source heterogeneous data fusion technology, the core BIM files of the architectural design institute and the lidar measured point cloud data of the underground corridor are jointly analyzed and compiled. In response to the "chimney effect" and abnormal wind pressure phenomenon that are prone to occur in super high-rise buildings due to internal and external temperature differences, the fluid dynamic air resistance coefficient and temperature gradient parameters of elevator shafts and stairwells are set in detail in the three-dimensional digital model. At the same time, the three-dimensional geometric shape of the smoke-proof stairwells and anterooms of the refuge floors on the 15th and 30th floors is accurately restored.

[0045] Steps 3 and 4: Input and fitting of fire protection configuration data. In this case of a super high-rise building, the input fire protection configuration data is more stringent: the inpatient ward area is equipped with fast response sprinklers, and the response time parameter is required to be ≤15 seconds. The core circulation channels of the entire building (stairwells and shared vestibules) all adopt independent ultra-high power mechanical positive pressure air supply systems (to resist backflow of smoke during high-rise fires), and differential pressure sensing automatic regulating air valves are installed at the end of the pipes on each floor. Subsequently, the coordinates of tens of thousands of tiny fire protection devices throughout the building are projected into the ultra-high-rise three-dimensional building grid.

[0046] Step 5: Based on the risk scenario preset according to the hospital and research attributes, and taking into account the special nature of the building, apply the physical equations of fire development. Reset the three-level risk test: Level 1 Scenario: Located inside the cardiovascular examination room on the 5th floor, an initial fire was caused by an overload and short circuit of a large CT medical imaging device. The peak power of the fire source was set at 50kW. Although the fire was small, the equipment was expensive and the surrounding people were unlikely to be frightened.

[0047] Scenario 2: In a research laboratory on the 28th floor, an operational error by the experimenters caused a large amount of alcohol chemical reagents to spill and cause a fire. The fire spread rapidly, and the maximum output power of the fire source soared to 2000kW.

[0048] Level 3 Scenario: A rare situation of superimposed external disasters, set in a winter weather with strong winds. An unexpected external fire source ignites the thermal insulation material on the 12th floor of the building. With the help of strong winds, the fire spreads rapidly upwards along the exterior wall. The total concurrent power of the fire source is as high as 8000kW. At the same time, a large amount of thick smoke begins to penetrate into the building due to wind pressure, forming an extremely large-scale three-dimensional fire.

[0049] Step 6: High-difficulty dynamic fire simulation exercise.

[0050] This phase emphasizes the analysis of movement behavior parameters for specific population groups. In the formula Reduction calculation in the middle: For general areas, the standard evacuation speed is 1.2 m / s. However, in the inpatient ward area (floors 11-25), the system identifies special medical attributes and automatically adjusts the combined evacuation speed for stretcher and wheelchair users. The speed is reduced drastically to 0.3 m / s, which will result in the calculated speed in this region being significantly lower. It has seen an exponential surge.

[0051] In the scenario simulation at the level 2 laboratory, although the personnel in the fire-prone laboratory were quickly evacuated, the simulation engine solved the Gaussian flue gas diffusion equation. It was keenly observed that due to the overly narrow design of the smoke extraction system ducts on the 28th floor, smoke extraction was obstructed. Toxic fumes began to overflow from the corridor and attempt to seep into the stairwell approximately 200 seconds after the fire started. Fortunately, the positive pressure ventilation system operated at full capacity in a very short time, and the powerful positive pressure airflow successfully sealed the gaps in the fire doors of the stairwell, preventing the smoke from spreading. The value continued to rise within the evacuation routes.

[0052] In a scenario involving a large-scale fire on a level-three exterior wall, the highest temperature in the fire scene is reached due to simultaneous air intake from multiple floors and resistance from wind direction. The temperature rapidly exceeded 800 degrees Celsius. Simulation results indicated that after some floors' exterior windows shattered, large amounts of toxic fumes poured in. Because the evacuation speed of the patient population was only 0.3 m / s, the transfer to the 15th-floor refuge floor took an extremely long time. Due to the rapid deterioration of the environment, the calculated available safe time... The system detected a significant reduction in evacuation time, specifically between floors 18 and 22. This was attributed to a slower evacuation rate for some patients. It reached an astonishing 850 seconds, exceeding the calculated environmental tolerance critical limit for the region. (Approximately 720 seconds).

[0053] Steps 7 and 8: Adaptive weighted evaluation of social attributes and decision output.

[0054] In the quantitative scoring phase, through analysis based on a social attribute management matrix, the system recognized that the consequences of casualties in a medical building would be unimaginable, thus mandating the enhancement of evacuation and support capabilities. The evaluation weighting has been significantly increased from 30% for conventional commercial buildings to 55%, while the weighting for pure equipment response time has been slightly reduced.

[0055] After substituting into the score calculation formula: Equipment response timeliness score : 94 points; Fire control capability score Due to the difficulty in effectively controlling fires on building facades, this item received a score of 65. Evacuation and support capability score The core score plummeted to 45 points due to the slow patient evacuation and the fact that the Level 3 scenario exceeded the time limit. Risk coverage score 60 points.

[0056] Finally, substitute into the overall evaluation formula The system calculated and output a severe evaluation report to the management department, which scored only 58 points (unsatisfactory).

[0057] This result overturned the traditional notion that "installing equipment guarantees compliance," pointing out a fatal flaw from the perspective of in-depth management decision-making. The system simultaneously issued a targeted configuration optimization decision list: First, the cross-sectional area of ​​the exhaust ducts in the laboratory area above the 26th floor must be expanded and modified to ensure that the flue gas is extracted more quickly under extreme conditions. Second, given the speed of patient evacuation Given the objective physical limitations, simply expanding stairwells is insufficient. It is recommended that each floor of the inpatient ward (floors 11-25) be equipped with a separate pressurized smoke-proof refuge room and sufficient oxygen masks. The strategy should be changed from "long-distance evacuation downwards" to "in-situ, horizontal, nearby refuge," thereby artificially increasing the upper limit of the safe available time. To cover longer transfer times; Third, the entire external wall insulation system must be replaced with Class A non-combustible materials to cut off the three-dimensional spread of the virus at its source.

[0058] The two specific and detailed implementation cases mentioned above not only demonstrate that the present invention can adapt to the digital evaluation requirements of different geometric shapes and building types on a macro level, but also fully demonstrate its quantitative evaluation capability based on a precise underlying physical mathematical model. Through a dynamic adjustment weight mechanism of social attributes, the present invention successfully transforms cold engineering data into decision-making solutions that can be directly adopted by government public safety departments and emergency management command centers, providing a solid, effective and interpretable systematic tool support for identifying urban building fire hazards in advance and scientifically optimizing the allocation of fire protection resources.

[0059] The detailed descriptions above are merely preferred embodiments of this application and are not intended to limit the scope of protection and core principles of this invention. Any person skilled in the art who is familiar with digital fire protection modeling and computer system analysis may make conventional adaptive substitutions to the mathematical model parameters disclosed in this invention, or apply the method to other similar infrastructure scenarios such as underground integrated pipe corridors and large tunnel projects, without departing from the core framework, evaluation model ideas, and close logical connections of each step of this invention. Such equivalent substitutions, transformations, or derivative applications should undoubtedly be covered within the technical spirit and intent indicated by this invention.

Claims

1. A method for evaluating fire protection effectiveness using digital modeling, characterized in that, Includes the following steps: Collect the three-dimensional structural information of the target building; Based on the full three-dimensional structural information, a three-dimensional mesh spatial discretization process is performed to construct a high-precision three-dimensional digital model of the target building, which restores the spatial structural characteristics, aerodynamic ventilation logic, and material heat conduction and combustion properties of the target building from a physical dimension. Obtain the proposed fire protection configuration data of the target building through the data interaction interface; By using a spatial coordinate registration algorithm, the fire protection configuration data is mapped and fitted into the high-precision three-dimensional digital model to generate a fire protection layout digital model. In the virtual space, the spatial distribution network of fire protection facilities, the linkage response logic between facilities, and the characteristics of fire extinguishing and smoke exhaust intervention capabilities are restored, thereby realizing the virtual integration of physical buildings and fire protection facility configuration schemes. Based on the risk statistics data in the emergency management system and the functional attributes of the target building, a multi-level fire scenario matrix covering all risk levels is preset; In the fire protection layout digital model, parallel simulation calculation tasks are established for each preset fire scenario. Dynamic fire development thermodynamic equations and smoke diffusion calculation models are introduced to independently simulate the flame heat spread and diffusion process, the three-dimensional diffusion process of toxic smoke, the automatic activation response process of fire protection facilities after reaching the threshold, and the escape and evacuation process of people inside the building under multi-level fire conditions. Dynamic simulation characteristic data of each level of fire scenario are output in batches. Based on the dynamic simulation feature data and relying on the indicators of the emergency management public safety system, a quantitative evaluation and calculation system is constructed that includes four dimensions: equipment response timeliness, fire control capability, evacuation guarantee capability, and risk coverage capability. The sub-item scores and comprehensive evaluation quantitative scores of each dimension are calculated using a multi-dimensional weighted evaluation and calculation model. The quantitative assessment results are output through a visual interface. These results include individual fire-fighting efficiency indicators under different risk scenarios, overall comprehensive fire-fighting effect quantitative scores, and configuration optimization suggestions for weak links.

2. The fire protection effect evaluation method based on digital modeling according to claim 1, characterized in that, The full-scale structural 3D information is obtained through a combination of building information model import and analysis and multi-dimensional laser scanning. The full-scale structural 3D information includes the 3D spatial layout of each floor, indoor space dimensions, ventilation duct network parameters, combustion property indicators of building materials in each zone, and topological data of internal evacuation routes.

3. The fire protection effect evaluation method based on digital modeling according to claim 1, characterized in that, The fire protection configuration data includes the spatial coordinates, hardware models, response time parameters, hydraulic performance parameters, and wind performance parameters of the automatic sprinkler system, indoor and outdoor fire hydrant system, mechanical smoke exhaust and positive pressure ventilation system, and automatic fire alarm system. The fire protection layout digital model allows for dynamic adjustment of configuration parameters and spatial locations in the fire protection configuration data through an interactive interface.

4. The fire protection effect evaluation method based on digital modeling according to claim 1, characterized in that, The multi-level fire scenario matrix includes three risk levels: The first-level scenario is defined as an initial small fire, which corresponds to an initial fire caused by a local electrical short circuit inside the building; A Level 2 scenario is defined as a fire in the development stage, corresponding to a medium-sized fire caused by localized dense combustibles that has already shown a tendency to spread; Level 3 scenario is defined as an extreme fire, corresponding to an extreme fire in which a large area of ​​multiple floors is simultaneously engulfed in mixed fuels.

5. The fire protection effect evaluation method based on digital modeling according to claim 1, characterized in that, In the aforementioned dynamic fire development thermodynamic equation, a dynamic quadratic growth model is used to characterize the increase in fire source power: ； in, for The dynamic heat release rate of the fire source at any given moment; Fire growth coefficient to characterize the properties of different combustibles; This refers to the cumulative duration calculated from the start of the fire.

6. The fire protection effect evaluation method based on digital modeling according to claim 1, characterized in that, The smoke diffusion calculation model uses a variant Gaussian three-dimensional diffusion equation to calculate the three-dimensional concentration distribution field of toxic smoke within the building space: ； in, The real-time concentration of flue gas at a specific coordinate point in space at a specific time; This represents the total mass of smoke gas released cumulatively from the time the fire occurred until the calculated time. The overall smoke diffusion coefficient is affected by the building's internal ventilation and temperature difference. The relative diffusion time of smoke from the source of the fire to its spatial spread; The spatial three-dimensional coordinates of the nodes to be calculated inside the three-dimensional digital model of the building; To determine the three-dimensional center coordinates of the fire source.

7. The fire protection effect evaluation method based on digital modeling according to claim 1, characterized in that, The simulation of the escape and evacuation process uses a multivariate time accumulation model to calculate the evacuation time: ； in, The total evacuation time required for people in a specific area to escape to a safe zone; To identify the detection alarm time when a fire alarm detector reaches the response threshold; The response time for personnel to confirm and prepare for action after receiving an alarm; This refers to the actual length of the evacuation route after avoiding the smoke hazard area; To take into account the actual movement speed of people after the reduction of population density.

8. The fire protection effect evaluation method based on digital modeling according to claim 1, characterized in that, The sub-item scores for the four dimensions are calculated in the following manner: Equipment response timeliness score: ； in, The score is used to evaluate the timeliness of equipment response. The response time penalty coefficient set for delayed startup; This is the calculation time for the actual triggering and activation of fire-fighting equipment in the virtual simulation; This refers to the permissible start-up time for this equipment as specified in current fire protection regulations. Fire control capability score: ； in, Scoring is given based on fire control capabilities; This refers to the actual horizontal area of ​​combustion burns calculated at the end of the virtual simulation. The total horizontal area of ​​the independent fire compartment to which the fire originated; The critical temperature threshold that the main structure of a building can withstand without collapsing or failing; This refers to the actual peak environmental temperature detected and recorded within the fire scene during the simulation process; Evacuation support capability score: ； in, Scoring is based on evacuation capacity; The upper limit of available safe evacuation time that can be provided before the smoke layer in the built environment settles to a critical danger height; The total evacuation time required for people in a specific area to escape to a safe zone; Risk coverage score: ； in, The overall score is based on risk coverage capability; This represents the total number of preset risk scenario levels. For the first The weighting coefficient of risk scenarios in the evaluation system; For the fire protection system in the first The score is the overall performance of each item after timeliness, control, and evacuation calculations under a level-one risk scenario.

9. The fire protection effect evaluation method based on digital modeling according to claim 8, characterized in that, The comprehensive evaluation score is calculated using the following formula: ； in, The quantitative comprehensive score for the building's fire protection configuration system; These represent the weighting of scores in the four dimensions of equipment response timeliness, fire control capability, evacuation guarantee capability, and risk coverage capability in the management decision evaluation. The The system extracts and assigns values ​​based on preset weight ratios from the social attribute parameters of the target building. These social attribute parameters include plot ratio, peak pedestrian flow, and industry category, and must satisfy the following conditions: .

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