Tunnel cable fire early warning method and system

Abstract

The invention relates to a tunnel cable fire early warning method and system, and the method comprises the steps: determining an arc fire diffusion grade according to a tunnel structure, and determining an ignition grade between cables according to the material, number and position relation of the cables in a tunnel; constructing a tunnel cable static three-dimensional model according to the tunnel structure and the number and position relation of the cables in the tunnel; constructing a fire diffusion dynamic model according to the arc fire diffusion grade, the ignition grade between the cables and the arc duration; compounding the two models to obtain a tunnel cable fire composite dynamic model; and performing fire trend analysis according to the composite dynamic model, and performing early warning. According to the method, tunnel structure parameters and cables are comprehensively considered, the method is more comprehensive and perfect, the static model and the dynamic model are established respectively, and then the composite dynamic model is established, so that the fire dynamic state can be mastered more conveniently and timely; the fire trend is analyzed, early warning is performed according to the analysis result, the early warning accuracy is improved, and the fire extinguishing efficiency is improved.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to the technical field of power disaster warning, and particularly to a method and system for warning of tunnel cable fires. Background Art

[0002] With the continuous expansion of the power grid scale, the number of cables in transmission and distribution lines is increasing day by day. In tunnels, there are numerous cables laid. Due to the high electrical load and difficult daily maintenance, fire accidents are likely to occur. For example, an arc caused by a single-phase grounding fault of a distribution cable can ignite other cables in the tunnel, leading to the spread of a fire accident and causing huge losses.

[0003] In related technologies, the accuracy of the prediction model for cable fires is low, and the reliability is low, which cannot effectively ensure the safe operation of cables.

[0004] Therefore, it is necessary to improve one or more problems existing in the above-mentioned related technical solutions.

[0005] It should be noted that this part is intended to provide background or context for the technical solutions of the present disclosure stated in the claims. The description herein is not admitted to be prior art merely because it is included in this part. Summary of the Invention

[0006] The purpose of the embodiments of the present disclosure is to provide a method and system for warning of tunnel cable fires, and thus at least to some extent overcome one or more problems caused by the limitations and defects of related technologies.

[0007] The embodiments of the present disclosure first provide a method for warning of tunnel cable fires, including the following steps:

[0008] Determine the arc fire spread level according to the tunnel structure, and determine the ignition level between cables according to the material, quantity and positional relationship of the cables in the tunnel;

[0009] Construct a static three-dimensional model of tunnel cables according to the tunnel structure, the quantity of cables in the tunnel, and the positional relationship;

[0010] Construct a dynamic fire spread model according to the arc fire spread level, the ignition level between cables, and the arc duration;

[0011] Composite the static three-dimensional model of tunnel cables and the dynamic fire spread model to obtain a composite dynamic model of tunnel cable fires;

[0012] Conduct a fire trend analysis according to the composite dynamic model, and issue a warning according to the analysis result.

[0013] In an embodiment of the present disclosure, the process of determining the arc fire spread level according to the tunnel structure includes:

[0014] Collect tunnel structure parameters;

[0015] Calculate the arc fire spread rate v according to the structure parameters, and the formula is as follows:

[0016]

[0017] In the formula, k is the material combustion characteristic coefficient, Q is the heat release rate, and W and H are the width and height of the tunnel respectively;

[0018] Calculate the spread area A of the arc fire, and the formula is as follows:

[0019]

[0020] In the formula, L is the longitudinal extension length of the arc flame;

[0021] Determine the spread level according to the criterion formula, and determine the spread level according to the spread level score. The formula is as follows:

[0022]

[0023] In the formula, S is the spread level score, Q max represents the maximum heat release rate, A total represents the total spread area of the arc fire, v max represents the maximum arc fire spread rate.

[0024] In an embodiment of the present disclosure, when S < 0.5, the spread level is level one; when 0.5 ≤ S ≤ 0.8, the spread level is level two; when S > 0.8, the spread level is level three.

[0025] In an embodiment of the present disclosure, the steps of determining the ignition level between cables according to the material, quantity and positional relationship of the cables in the tunnel include:

[0026] The calculation formula for determining the ignition level between cables according to the material, quantity and positional relationship of the cables in the tunnel is as follows:

[0027]

[0028] In the formula, R is the heat flux density, Q' represents the heat release per unit length, I is the load current, T0 is the ambient temperature of the tunnel, K is the correction coefficient, and D is the cable spacing;

[0029] Determine the ignition level according to the value of the heat flux density R.

[0030] In an embodiment of the present disclosure, when R > 100 kW / m 2When [condition not specified], the ignition level is grade three; when 70 ≤ R ≤ 100, the ignition level is grade two; when R < 70, the diffusion level is grade one.

[0031] In one embodiment of the present disclosure, a method combining a diffusion equation and three-dimensional space discretization technology is used to construct a composite dynamic model of tunnel cable fire through time-domain iteration.

[0032] In one embodiment of the present disclosure, the analytic hierarchy process and the fuzzy comprehensive evaluation method are used to determine the fire warning level, and then corresponding treatment measures are taken according to the fire warning level.

[0033] The embodiment of the present disclosure also provides a tunnel cable fire warning system, and the system includes:

[0034] An ignition level determination module, configured to determine the arc fire diffusion level according to the tunnel structure, and determine the ignition level between cables according to the material, quantity and positional relationship of the cables in the tunnel;

[0035] A static three-dimensional model construction module, configured to construct a static three-dimensional model of tunnel cables according to the tunnel structure, the quantity of cables in the tunnel, and the positional relationship;

[0036] A diffusion dynamic model construction module, configured to construct a fire diffusion dynamic model according to the arc fire diffusion level, the ignition level between cables, and the arc duration;

[0037] A composite dynamic model construction module, configured to composite the static three-dimensional model of tunnel cables and the fire diffusion dynamic model to obtain a composite dynamic model of tunnel cable fire;

[0038] An analysis and warning module, configured to perform fire trend analysis according to the composite dynamic model and issue a warning according to the analysis result.

[0039] The technical solution provided by the embodiment of the present disclosure may include the following beneficial effects:

[0040] A tunnel cable fire warning method and system in the embodiment of the present disclosure, by comprehensively considering tunnel structure parameters and cables, makes the factors involved in cable fire more comprehensive and perfect. By separately establishing a static model and a dynamic model, the model is made more accurate. Then, by establishing a composite dynamic model, the fire dynamics can be more conveniently and timely grasped; by analyzing the fire trend and issuing a warning according to the analysis result, the warning accuracy is improved and the fire extinguishing efficiency is improved. Brief Description of the Drawings

[0041] The accompanying drawings here are incorporated into and constitute a part of this specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure. Obviously, the accompanying drawings in the following description are only some embodiments of the present disclosure, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0042] Figure 1 A schematic flow chart showing a method for early warning of tunnel cable fires in an exemplary embodiment of the present disclosure;

[0043] Figure 2 A schematic structural diagram showing an electronic device in an exemplary embodiment of the present disclosure;

[0044] Figure 3 A schematic structural diagram showing a program product for implementing the method for early warning of tunnel cable fires in an exemplary embodiment of the present disclosure. Detailed implementation manners

[0045] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be more complete and will fully convey the concept of the example embodiments to those skilled in the art. The features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments.

[0046] In addition, the accompanying drawings are only schematic illustrations of the embodiments of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus their repeated description will be omitted. Some of the block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0047] In this example embodiment, a method for early warning of tunnel cable fires is first provided. Please refer to Figure 1 , which may include: step S101 - step S105. Specifically as follows:

[0048] Step S101, determining the arc fire spread level according to the tunnel structure, and determining the ignition level between cables according to the material, quantity, and positional relationship of the cables in the tunnel;

[0049] Step S102, constructing a static three-dimensional model of the tunnel cables according to the tunnel structure, the quantity of the cables in the tunnel, and the positional relationship;

[0050] Step S103, constructing a dynamic fire spread model according to the arc fire spread level, the ignition level between cables, and the arc duration;

[0051] Step S104: Combine the static 3D model of the tunnel cable and the dynamic model of fire spread to obtain a composite dynamic model of tunnel cable fire.

[0052] Step S105: Conduct a fire trend analysis based on the composite dynamic model and issue a warning according to the analysis results.

[0053] In this embodiment, by comprehensively considering the tunnel structure parameters and cables, the factors involved in cable fires are made more comprehensive and perfect. By establishing static and dynamic models respectively, the models are made more accurate. Then, by establishing a composite dynamic model, the fire dynamics can be grasped more conveniently and in a timely manner. Through the analysis of the fire trend and issuing a warning according to the analysis results, the warning accuracy is improved and the fire extinguishing efficiency is increased.

[0054] The above steps are described in more detail below.

[0055] In step S101, the process of determining the arc fire spread level according to the tunnel structure includes:

[0056] (1) Collect tunnel structure parameters, such as material thermal conductivity, specific heat capacity, density, tunnel cross-sectional dimensions, ventilation system flow rate, and partition setting spacing, etc.

[0057] (2) Calculate the arc fire spread rate v according to the structure parameters. The formula is as follows:

[0058]

[0059] In the formula, k is the material combustion characteristic coefficient, Q is the heat release rate, and W and H are the width and height of the tunnel respectively. Usually, the value range of k is 0.01 - 0.05. In high-risk scenarios, the value range of k will increase by 0.03 - 0.05.

[0060] Calculate the arc fire spread area A. The formula is as follows:

[0061]

[0062] In the formula, L is the longitudinal extension length of the arc flame.

[0063] (3) Determine the spread level according to the criterion formula and determine the spread level according to the spread level score. The formula is as follows:

[0064]

[0065] In the formula, S is the spread level score, Q max represents the maximum heat release rate, A total represents the total spread area of the arc fire, and v max represents the maximum arc fire spread rate.

[0066] Among them, when S < 0.5, the diffusion level is the first level; when 0.5 ≤ S ≤ 0.8, the diffusion level is the second level; when S > 0.8, the diffusion level is the third level. The higher the level, the higher the corresponding harm degree.

[0067] In step S101, the steps of determining the ignition level between cables according to the material, quantity and positional relationship of the cables in the tunnel include:

[0068] The calculation formula for determining the ignition level between cables according to the material, quantity and positional relationship of the cables in the tunnel is as follows:

[0069]

[0070] In the formula, R is the heat flux density, Q’ represents the heat release per unit length, I is the load current, T0 is the ambient temperature of the tunnel, n represents the number of cables, K is the correction coefficient, and D is the cable spacing;

[0071] Determine the ignition level according to the value of the heat flux density R.

[0072] In this embodiment, when R > 100 kW / m 2 , the ignition level is the third level; when 70 ≤ R ≤ 100, the ignition level is the second level; when R < 70, the diffusion level is the first level. The lower the level, the lower the corresponding harm degree.

[0073] In the process of constructing a static three-dimensional model of tunnel cables according to the tunnel structure, the number of cables in the tunnel and the positional relationship, combine the tunnel structure, the number of cables and the positional relationship with the ignition level for three-dimensional model rendering. Divide the ignition level into three levels, and display them with different colors respectively. The first level with the lowest danger level is represented by green, the second level by yellow, and the third level by yellow.

[0074] Construct a dynamic model of fire spread according to the arc fire diffusion level, the ignition level between cables and the arc duration, that is, a model diagram of the change of the arc fire diffusion level and the ignition level between cables with the arc duration. In this process, a basic database can be constructed according to historical fire events, and then combined with the parameters of the current fire accident as input quantities to predict the fire spread situation in advance, providing more time for repair personnel and minimizing the losses caused by the fire to the greatest extent.

[0075] This application does not specifically limit the construction methods of the above models, and shall be subject to what can be achieved by the prior art. For example, perform structure construction through 3D software, then perform UV mapping, define key poses on the time axis, define key poses of the model and set key frames on the time axis through interpolation algorithms, etc., and then perform rendering output, etc.

[0076] An embodiment of the present invention further provides a tunnel cable fire warning system, including:

[0077] An ignition level determination module for determining the arc fire spread level according to the tunnel structure, and determining the ignition level between cables according to the material, quantity, and positional relationship of the cables in the tunnel;

[0078] A static three-dimensional model construction module for constructing a static three-dimensional model of tunnel cables according to the tunnel structure, the quantity of cables in the tunnel, and the positional relationship;

[0079] A diffusion dynamic model construction module for constructing a fire diffusion dynamic model according to the arc fire spread level, the ignition level between cables, and the arc duration;

[0080] A composite dynamic model construction module for combining the static three-dimensional model of tunnel cables and the fire diffusion dynamic model to obtain a tunnel cable fire composite dynamic model;

[0081] An analysis and warning module for analyzing the fire trend according to the composite dynamic model and giving a warning according to the analysis result.

[0082] In this embodiment, by comprehensively considering the tunnel structure parameters and cables, the factors involved in cable fires are made more comprehensive and perfect. By establishing a static model and a dynamic model respectively, the models are made more accurate. Then, by establishing a composite dynamic model, the fire dynamics can be grasped more conveniently and timely. By analyzing the fire trend and giving a warning according to the analysis result, the warning accuracy is improved and the fire extinguishing efficiency is increased.

[0083] The specific operation process in the system is consistent with the steps in the foregoing tunnel cable fire warning method, and will not be elaborated herein.

[0084] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment related to the method, and will not be elaborated herein.

[0085] It should be noted that although several modules of the system for action execution are mentioned in the foregoing detailed description, this division is not mandatory. In fact, according to the embodiments of the present invention, the features and functions of two or more of the above-described modules can be embodied in one module. Conversely, the features and functions of one module described above can be further divided and embodied by multiple modules. The components shown as modules may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of the present invention. Those of ordinary skill in the art can understand and implement it without creative effort.

[0086] See Figure 2 , an embodiment of the present invention further provides an electronic device 300, which includes at least one memory 310, at least one processor 320, and a bus 330 connecting different platform systems.

[0087] The memory 310 may include a readable medium in the form of a volatile memory, such as a random access memory (RAM) 311 and / or a cache memory 312, and may further include a read-only memory (ROM) 313.

[0088] Among them, the memory 310 further stores a computer program, which can be executed by the processor 320, so that the processor 320 executes the steps of the tunnel cable fire warning method in any embodiment of the present invention. The specific implementation manner is the same as the implementation manner and the achieved technical effect recorded in the embodiment of the above tunnel cable fire warning method, and some contents will not be repeated.

[0089] The memory 310 may further include a utility 314 having at least one program module 315. Such program modules 315 include, but are not limited to: an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include the implementation of a network environment.

[0090] Correspondingly, the processor 320 can execute the above computer program and can execute the utility 314.

[0091] The bus 330 may represent one or more of several types of bus structures, including a memory bus or a memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any bus structure in a variety of bus structures.

[0092] The electronic device 300 can also communicate with one or more external devices 340 such as keyboards, pointing devices, Bluetooth devices, etc., and can also communicate with one or more devices capable of interacting with the electronic device 300, and / or communicate with any device (such as a router, a modem, etc.) that enables the electronic device 300 to communicate with one or more other computing devices. Such communication can be carried out through the input / output interface 350. Moreover, the electronic device 300 can also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through the network adapter 360. The network adapter 360 can communicate with other modules of the electronic device 300 through the bus 330. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in combination with the electronic device 300, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms, etc.

[0093] An embodiment of the present invention also provides a computer-readable storage medium, which is used to store a computer program. When the computer program is executed, the steps of the tunnel cable fire warning method in the embodiment of the present invention are implemented. The specific implementation manner is consistent with the implementation manner and the achieved technical effects recorded in the embodiment of the above-mentioned tunnel cable fire warning method, and some contents will not be elaborated again.

[0094] Figure 3 A program product 400 for implementing the above-mentioned tunnel cable fire warning method provided in this embodiment is shown. It can be a portable compact disc read-only memory (CD-ROM) and includes program code, and can run on a terminal device, such as a personal computer. However, the program product 400 of the present invention is not limited thereto. In the present invention, the readable storage medium can be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, apparatus, or device. The program product 400 can adopt any combination of one or more readable media. The readable media can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (non-exhaustive list) of the readable storage medium include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0095] A computer-readable storage medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the foregoing. The readable storage medium may also be any readable medium that can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wired, optical fiber cable, RF, etc., or any suitable combination of the foregoing. The program code for performing the operations of the present invention may be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, etc., and also including conventional procedural programming languages such as the C language or similar programming languages. The program code may be executed entirely on the user's computing device, partially on the user's device, executed as a stand-alone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user's computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or alternatively, may be connected to an external computing device (e.g., using an Internet service provider to connect through the Internet).

[0096] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit and scope protected by the present invention and the claims. All of these are within the protection scope of the present invention.

Claims

1. A method for early warning of tunnel cable fires, characterized in that, It includes the following steps: Determine the arc fire spread level according to the tunnel structure, and determine the ignition level between cables according to the material, quantity and positional relationship of the cables in the tunnel; Construct a static three-dimensional model of the tunnel cables according to the tunnel structure, the quantity of the cables in the tunnel and the positional relationship; Construct a dynamic fire spread model according to the arc fire spread level, the ignition level between cables and the arc duration; Compound the static three-dimensional model of the tunnel cables and the dynamic fire spread model to obtain a compound dynamic model of tunnel cable fire; Conduct a fire trend analysis according to the compound dynamic model, and give an early warning according to the analysis result.

2. The tunnel cable fire warning method according to claim 1, wherein, The process of determining the arc fire spread level according to the tunnel structure includes: Collect tunnel structure parameters; Calculate the arc fire spread rate v according to the structure parameters, and the formula is as follows: In the formula, k is the material combustion characteristic coefficient, Q is the heat release rate, and W and H are the width and height of the tunnel respectively; Calculate the spread area A of the arc fire, and the formula is as follows: In the formula, L is the longitudinal extension length of the arc flame; Determine the spread level according to the criterion formula, and determine the spread level according to the spread level score, and the formula is as follows: Where S is the diffusion level score, and Q max represents the maximum heat release rate, A total represents the total diffusion area of the arc fire, v max represents the maximum diffusion rate of the arc fire.

3. The tunnel cable fire warning method according to claim 2, wherein When S < 0.5, the spread level is grade one; when 0.5 ≤ S ≤ 0.8, the spread level is grade two; when S > 0.8, the spread level is grade three.

4. The tunnel cable fire warning method according to claim 1, characterized in that, The steps of determining the ignition level between cables according to the material, quantity and positional relationship of the cables in the tunnel include: The calculation formula for determining the ignition level between cables according to the material, quantity and positional relationship of the cables in the tunnel is as follows: In the formula, R is the heat flux density, Q' represents the heat release per unit length, I is the load current, T0 is the ambient temperature of the tunnel, K is the correction coefficient, and D is the cable spacing; Determine the ignition level according to the value of the heat flux density R.

5. The tunnel cable fire warning method according to claim 4, wherein, When R > 100 kW / m 2 the ignition rating is Class III; when 70 ≤ R ≤ 100, the ignition rating is Class II; when R < 70, the diffusion rating is Class I.

6. The tunnel cable fire warning method according to claim 1, wherein, Adopt a method combining the diffusion equation and the three-dimensional space discretization technology, and construct a compound dynamic model of tunnel cable fire through time-domain iteration.

7. The tunnel cable fire warning method according to any one of claims 1 to 6, characterized in that Adopt the analytic hierarchy process and the fuzzy comprehensive evaluation method to determine the fire early warning level, and then take corresponding treatment measures according to the fire early warning level.

8. A tunnel cable fire warning system, characterized in that, It includes: An ignition level determination module, which is used to determine the arc fire spread level according to the tunnel structure, and determine the ignition level between cables according to the material, quantity and positional relationship of the cables in the tunnel; A static three-dimensional model construction module, which is used to construct a static three-dimensional model of the tunnel cables according to the tunnel structure, the quantity of the cables in the tunnel and the positional relationship; A dynamic spread model construction module, which is used to construct a dynamic fire spread model according to the arc fire spread level, the ignition level between cables and the arc duration; A compound dynamic model construction module, which is used to compound the static three-dimensional model of the tunnel cables and the dynamic fire spread model to obtain a compound dynamic model of tunnel cable fire; An analysis and early warning module, which is used to conduct a fire trend analysis according to the compound dynamic model, and give an early warning according to the analysis result.

9. The tunnel cable fire warning system according to claim 8, wherein, Adopt a method combining the diffusion equation and the three-dimensional space discretization technology, and construct a compound dynamic model of tunnel cable fire through time-domain iteration.

10. The tunnel cable fire warning system according to claim 8, characterized in that, The analytic hierarchy process and the fuzzy comprehensive evaluation method are used to determine the fire warning level, and then corresponding treatment measures are taken according to the fire warning level.

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