Fire extinguishing system and method for a cable-stayed bridge cable

Abstract

The present application relates to cable-stayed bridge fire fighting technical field, especially to a kind of for cable-stayed bridge cable fire extinguishing system and method.Fire extinguishing system, including: fireproof water curtain system, foam fire extinguishing system and supply system;The fireproof water curtain system includes water curtain nozzle, the water curtain nozzle is set in the one side or both sides of cable along the bridge deck width direction, the water curtain nozzle is towards top and sprays water and spray water height is higher than predetermined value;The foam fire extinguishing system includes fire gun, and the fire gun is set on bridge deck;The supply system includes water pool and foam storage tank, and the water pool is communicated with the water curtain nozzle by water curtain fire pipe network, and the water pool and foam storage tank are communicated with the fire gun by foam fire pipe network.The lift and power of fire extinguishing system in the present application are low, the pressure borne by pipeline is low, not only can extinguish conventional fire, but also can extinguish dangerous chemical fire, and the aerodynamic stability of cable is not affected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cable-stayed bridge fire fighting, and in particular to a fire extinguishing system and method for cable-stayed bridge cables. BACKGROUND

[0002] With the rapid development of the transportation industry, bridge fire accidents caused by traffic accidents occur from time to time, especially when a vehicle transporting dangerous chemicals catches fire, which can cause serious damage to the bridge structure.

[0003] As an important load-bearing member of cable-supported bridge system, the cable is threatened by the failure of the sealed anticorrosion structure and fire during the operation stage. Studies have shown that the mechanical properties of the cable decrease by 1 / 4 at 300℃, and the mechanical properties of the cable decrease significantly at 400℃, or even fail. When the fire is extinguished, irreversible damage occurs inside the steel wire, which poses a serious threat to the safe operation of the bridge.

[0004] Dangerous chemical traffic fires are sudden, burn quickly, and have strong radiation. In general, water alone cannot extinguish the fire, the center temperature of the flame can reach 1300℃, and the emergency fire truck takes a long time to arrive at the scene. Once there is traffic congestion, the best fire extinguishing time is easily missed, causing significant economic losses and safety incidents. SUMMARY

[0005] In view of the deficiencies in the prior art, the purpose of the embodiments of the present application is to provide a fire extinguishing system for cable-stayed bridge cables.

[0006] In order to achieve the above-mentioned purpose, the embodiments of the present application provide the following technical solutions:

[0007] A fire extinguishing system for cable-stayed bridge cables, comprising: a fireproof water curtain system, a foam fire extinguishing system and a supply system; the fireproof water curtain system comprises a water curtain nozzle, the water curtain nozzle is arranged on one side or both sides of the cable in the width direction of the bridge deck, the water curtain nozzle sprays water towards the top and the spraying height is higher than a predetermined value; the foam fire extinguishing system comprises a fire water gun, the fire water gun is arranged on the bridge deck; the supply system comprises a water pool and a foam tank, the water pool is communicated with the water curtain nozzle through a water curtain fire extinguishing pipe network, and the water pool and the foam tank are communicated with the fire water gun through a foam fire extinguishing pipe network.

[0008] Optionally, the water curtain nozzles on both sides of the cable are arranged towards the middle cable, forming a fireproof water curtain on both sides of the cable, and the height of the fireproof water curtain is higher than a set value.

[0009] Optionally, the supply system further comprises a pump house, the pump house is arranged on the ground and an air conditioner or an electric heater is arranged in the pump house.

[0010] Optionally, the pump house is provided with a water tank and a water pump, the water tank is connected to the water curtain fire extinguishing pipe network through a water pipe, a check valve is arranged on the water pipe, a gate valve is arranged between the water pump and the check valve, and an electric control valve is arranged on the water curtain fire extinguishing pipe network in front of the water curtain nozzle.

[0011] Optionally, the pump house is provided with a foam tank and a foam pump, the foam tank is connected to the foam fire extinguishing pipe network through a foam pipe, and a check valve is arranged on the foam pipe.

[0012] Optionally, the supply system further comprises a proportioning mixer, the water pipe and the foam pipe are connected to the inlet of the proportioning mixer, and the outlet of the proportioning mixer is connected to the foam fire extinguishing pipe network.

[0013] Optionally, the control system further comprises a detection unit and an automatic control center, the detection unit is signal connected with the automatic control center, and the automatic control center is signal connected with the control element in the pump house.

[0014] Optionally, the detection unit is one or more of smoke detection, digital video monitoring, dangerous gas detection, infrared induction detection and temperature induction detection.

[0015] The embodiment of the present application further provides a fire extinguishing method using the fire extinguishing system for the stay cable of the cable-stayed bridge, and the method comprises the following steps: when a fire occurs in the range of the stay cable, a fireproof water curtain is formed on one side or both sides of the stay cable by the water curtain nozzle to form a fire barrier and cool the stay cable; meanwhile, the foam liquid is sprayed to the fire source by the fire water gun to extinguish the fire; when the fire does not occur in the range of the stay cable, the foam liquid is sprayed to the fire source by the fire water gun to extinguish the fire.

[0016] Optionally, when the fire is over, the contaminated bridge deck is cleaned manually by the fire water gun.

[0017] The one or more technical solutions provided in the embodiment of the present application have at least the following technical effects or advantages:

[0018] The present application sets water curtain nozzles at intervals on the bridge deck, forms a fireproof water curtain on one side or both sides of the cable, and sprays foam mixed with water to the fire source by a fire gun. When the fire is in the range of the cable, the water curtain nozzles form a fireproof water curtain on one side or both sides of the cable, and the fire gun sprays foam to the fire source, so as to extinguish the fire. When the fire is not in the range of the cable, the fire gun sprays foam to the fire source, so as to extinguish the fire. Therefore, the present application does not set a sleeve on the cable, does not change the wind resistance coefficient of the cable, and does not affect the aerodynamic stability of the cable. The water curtain formed by the water curtain nozzles not only physically separates the fire from the cable, but also cools the cable, thereby protecting the cable. At the same time, the water curtain is formed by upward spraying, the water curtain nozzle has low lift and power, the pipeline bears low pressure, the cost is low, and it is easier to realize. Moreover, it can not only extinguish conventional fires, but also extinguish dangerous chemical fires. The present application not only passively cools, but also actively extinguishes the fire, and the water spraying cooling point is at the heat radiated cable, which can more effectively cool the cable and save water.

[0019] Advantages of the additional aspects of the present application will be given in the following description, some of which will become apparent from the following description, or will be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments described in the present application, and those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0021] Figure 1 is a schematic diagram of the fire extinguishing system of the embodiment of the present application;

[0022] Figure 2 is Figure 1 is an enlarged view of the upper part of the above;

[0023] Figure 3 is Figure 1 is an enlarged view of the middle part of the above;

[0024] Figure 4 is Figure 1 is an enlarged view of the lower part of the above;

[0025] Figure 5 is a schematic diagram of the elevation of the cable-stayed bridge of the embodiment of the present application;

[0026] Figure 6 is a schematic diagram of the plane of the cable-stayed bridge of the embodiment of the present application;

[0027] Figure 7 is a schematic diagram of the control principle of the embodiment of the present application;

[0028] In the figure: 1, inhaul cable; 2, fireproof water curtain; 3, water curtain nozzle; 4, electromagnetic valve; 5, foam fire extinguishing pipe network; 6, water curtain fire extinguishing pipe network; 7, air conditioner; 8, pump house; 9, water pool; 10, water pump; 11, gate valve; 12, foam storage tank; 13, foam pump; 14, check valve; 15, proportional mixer; 16, fire hose;

[0029] The mutual distance or size between each part is exaggerated for showing the position of each part, and the schematic diagram is only for illustration. DETAILED DESCRIPTION

[0030] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Furthermore, it should be understood that the use of the term "including", "comprising" or "having" herein is meant to encompass the presence of stated features, steps, operations, devices, components, and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components, and / or combinations thereof.

[0031] Chinese patent CN111905299A discloses a cable-stayed bridge fire-fighting device, which sets up an installation bin and a lifting bin on the bridge tower, the installation bin is provided with a main pipe stand, and the lifting bin is provided with an elevator. When a fire occurs on the cable-stayed bridge, the lifting mechanism lowers the water pumping mechanism into the water, the water pumping mechanism pumps the river water away from the main road water pipe along the bridge tower, the branch water pipe descends along the cable pipe cavity, and the spraying mechanism sprays the river water to the fire occurrence position, so that the fire at the fire occurrence position can be quickly extinguished. The device uses a large number of mechanical equipment, and the process is complex; and because the bridge tower is too high, the water pump and the pipe are required to be high; the cable is provided with a pipe cavity and a closed cavity, which changes the wind resistance coefficient of the cable; and in winter, the river surface is frozen, and water cannot be taken.

[0032] Chinese patent CN105944258A discloses a cable-stayed tower end fire-fighting system, which sets up a water tank at the top of the bridge tower and a spraying head at the top of the cable, collects the smoke signal by using a control cabinet, and sends a water spraying instruction to automatically and timely extinguish the fire. The system requires a very high water pump and pipe because the bridge tower is too high; at the same time, the system increases the structural load of the bridge tower; it is easy to freeze in winter; the cable is as long as several hundred meters, and water is sprayed only at the top of the cable, so the fire extinguishing effect is poor.

[0033] Chinese patent CN112900245A discloses a fireproof device for cable-stayed bridge cables and a mounting method thereof, which sets up a fire hydrant at the top of the bridge tower and a cable sleeve device at the cable, when a fire occurs, the water pump delivers water to the fire hydrant through the cable sleeve to complete fire extinguishing and cooling. Because the water pressure is required to be very high, the water pump and the pipe are required to be very high; it is easy to freeze in winter; the cable is provided with a cable sleeve, which changes the wind resistance coefficient of the cable.

[0034] Therefore, there are currently no national or industry standards or guidelines for fire protection of bridge cables, no mature technical system, and only a few related studies. Moreover, they all adopt passive fire protection methods such as cable ties, and their fire protection systems need to consider factors such as failure caused by joints, resistance to environmental aging, protection against ultraviolet rays, protection against acid rain corrosion, waterproofing, and adaptation to structural vibration. They also change the wind resistance coefficient of the cables, affecting the aerodynamic stability of the cables. They all use water to extinguish fires, but in the case of hazardous chemical fires, water can only cool down the fire and cannot extinguish it. In addition, there are defects such as extremely high water pressure, extremely high requirements for water pumps and pipelines, and particularly large power consumption. At the same time, they are not antifreeze, which makes them unsuitable for practical application and promotion.

[0035] To address the aforementioned technical problems, this invention proposes a fire extinguishing system for the cable-stayed bridge cable 1, such as... Figure 1 As shown, the system includes: a fire-resistant water curtain 2 system, a foam extinguishing system, and a supply system; the fire-resistant water curtain 2 system includes water curtain nozzles 3, which are installed on one or both sides of the cable 1 along the width of the bridge deck, and spray water upwards at a height higher than a predetermined value; the foam extinguishing system includes fire hoses 16, which are installed on the bridge deck; the supply system includes a water tank 9 and a foam storage tank 12, the water tank 9 being connected to the water curtain nozzles 3 through a water curtain extinguishing pipeline network 6, and the water tank 9 and the foam storage tank 12 being connected to the fire hoses 16 through a foam extinguishing pipeline network 5.

[0036] like Figure 2 , Figure 4 As shown, this invention involves installing water curtain nozzles 3 at intervals on the bridge deck, positioned on one or both sides of the cable (i.e., the tension cable 1), with the nozzles 3 biased towards the center of the tension cable 1. This creates a fireproof water curtain 2 on both sides of the tension cable 1. Foam is mixed with water and sprayed onto the fire source by fire hoses 16. When the fire is within the range of the tension cable 1, the fireproof water curtain 2 formed by the water curtain nozzles 3 on both sides of the tension cable 1 provides fire resistance and cooling. Simultaneously, the fire hoses 16 spray the foam liquid onto the fire source to extinguish the fire. When the fire is not within the range of the tension cable 1, the fire hoses 16 spray the foam liquid onto the fire source to extinguish the fire. Therefore, this invention does not use sleeves on the cable, does not change the cable's drag coefficient, and does not affect the cable's aerodynamic stability. The water curtain formed by the water curtain nozzles 3 not only physically isolates the fire from the cable but also cools the cable, thus protecting it. Meanwhile, by spraying water upwards to form a water curtain, the water curtain nozzles have low head and power, resulting in low pressure on the pipeline, low cost, and easier implementation. Moreover, it can extinguish not only conventional fires but also fires involving hazardous chemicals. This invention not only provides passive cooling but also active fire suppression, and the water spray cooling point is located directly at the point of heat radiation on the cable, enabling more effective cooling of the cable and saving more water.

[0037] According to the simulation research of fire temperature-height distribution related to oil tank truck, the temperature in the range above 17m will be lower than 300℃, so the water curtain nozzle 3 in this embodiment is higher than 17m.

[0038] As shown in Figure 5 , Figure 6 , the supply system further comprises a pump house 8, which is arranged on the ground and an air conditioner 7 is arranged in the pump house 8 to avoid water icing in the pump house 8. As shown in Figure 3 , a water tank 9 and a water pump 10 are arranged in the pump house 8, the water tank 9 is connected to the water curtain fire extinguishing pipe network 6 through a water pipe, a check valve 14 is arranged on the water pipe to prevent air or water from flowing in the opposite direction. A gate valve 11 is arranged between the water pump 10 and the check valve 14, and an electric control valve such as an electromagnetic valve 4 or an electric valve is arranged on the water curtain fire extinguishing pipe network 6 in front of the water curtain nozzle 3. The water curtain nozzle 3 is controlled by the electromagnetic valve 4, and after the electromagnetic valve 4 near the fire is opened, the water curtain nozzle 3 at the heated cable sprays water to form a water curtain, which physically separates the fire source from the cable, achieving the purpose of fire resistance; at the same time, the scattered water wets the cable, cooling the cable.

[0039] A foam tank 12 and a foam pump 13 are arranged in the pump house 8, the foam tank 12 is connected to the foam fire extinguishing pipe network 5 through a foam pipe, or a tank pressure type foam is directly connected to the pipe, and the foam pump 13 delivers the foam in the foam tank 12 to the pipe network, and a check valve 14 is arranged on the foam pipe. Further, the supply system further comprises a proportional mixer 15, the water pipe and the foam pipe are connected to the inlet of the proportional mixer 15, and the outlet of the proportional mixer 15 is connected to the foam fire extinguishing pipe network. The foam liquid and water are mixed in proportion by the proportional mixer 15 to form foam liquid for fire extinguishing, which can adhere to the combustible material to isolate the combustible material from the air, while reducing the temperature, destroying the combustion condition, and achieving the purpose of fire extinguishing. Foam fire extinguishing is generally used for chemical fires, and should be stored in dry and cool places, and should not be close to high temperature or may be exposed to sunlight.

[0040] As shown in Figure 7 , the fire extinguishing system of the embodiment further comprises a control system, the control system comprises a detection unit and an automatic control center, the detection unit is signal connected with the automatic control center, and the automatic control center is signal connected with the control elements in the pump house 8. The automatic control center processes the collected signals to control the operation of the control system. The detection unit is one or more of smoke detection, digital video monitoring, hazardous gas detection, infrared sensing detection and temperature sensing detection, or can simulate the temperature distribution of the fire.

[0041] When a fire occurs, there are two cases:

[0042] When the fire is in the range of the cable, the smoke detection, digital video monitoring, dangerous gas detection or infrared induction detector sends a signal, the water pump 10 is started, and the electromagnetic valve 4 in front of the water curtain nozzle 3 is started, the water curtain nozzle 3 sprays water to form a water curtain, the cable is formed to form a fire resistance and cooling; meanwhile, the foam pump 13 is started, the water and the foam are mixed in proportion through the proportional mixer 15, the fire gun 16 automatically tracks the fire source, the foam is sprayed to the fire source, and the fire is extinguished.

[0043] When the fire is not in the range of the cable, the electromagnetic valve 4 is not actuated; the smoke detection, digital video monitoring, dangerous gas detection or infrared induction detector sends a signal, the water pump 10 is started, and the foam pump 13 is started, the water and the foam are mixed in proportion through the proportional mixer 15, the fire gun 16 automatically tracks the fire source, the foam is sprayed to the fire source, and the fire is extinguished.

[0044] After the fire is extinguished, the foam pump 13 is closed, and the fire gun 16 is manually controlled, so that the contaminated bridge deck can be cleaned.

[0045] The fire extinguishing system of the present application shares a set of water pump 10, the water pump 10 and the water tank 9 are arranged in the pump house 8, the water tank 9 stores fire-fighting water required for fire extinguishing and cooling, and the air conditioner 7 or the electric heater is arranged in the pump house 8 to ensure that the temperature is not lower than 4 DEG C in winter. The water curtain nozzle 3 is arranged at intervals on the bridge deck and is arranged on one side or both sides of the cable, and the electromagnetic valve 4 is arranged in front of the water curtain nozzle 3. The foam storage tank 12 and the foam pump 13 are also arranged in the pump house 8, the foam storage tank 12 stores the foam for extinguishing the dangerous chemicals, the fire gun 16 is arranged at intervals on the bridge deck, and the fire gun 16 has the function of automatically locating the fire. After the fire occurs, the foam and the water are mixed and sprayed out by the fire gun 16 to extinguish the fire. Compared with the existing fire extinguishing system, the present application has the following technical effects:

[0046] ①The present application does not arrange a sleeve on the cable, does not change the wind resistance coefficient of the cable, and does not affect the aerodynamic stability of the cable, thereby improving the safety of the cable structure. At the same time, the water curtain formed by the water curtain nozzle can not only physically separate the fire from the cable, but also cool the cable, thereby protecting the cable.

[0047] ②For the problem that the water for dangerous chemicals can only be cooled but cannot be extinguished, the present application arranges the foam, which can not only extinguish the conventional fire, but also extinguish the dangerous chemical fire.

[0048] ③The tower of the suspension bridge is at least 100 meters high, and the existing method is to lift the water to the top of the tower and then extinguish the fire. The water pump has large power and the system has extremely high pressure, and the existing materials are difficult to realize. The present application has low water pump lift and power, low pressure of the pipeline and low cost, and is easier to realize.

[0049] ④The present application not only passively cools but also actively extinguishes the fire, and the water spraying cooling point is just at the heat radiated cable, which can more effectively cool the cable and save water.

[0050] Compared with the fireproof system provided with a lasso, the application does not need to consider the factors such as joint failure, environmental aging resistance, ultraviolet resistance, acid rain corrosion resistance, water resistance and structure vibration adaptation, has a longer service life, is more stable and has a lower cost, and is easy to implement.

[0051] The above describes the specific embodiments of the application in combination with the drawings, but is not a limitation on the protection scope of the application, and those skilled in the art should understand that various modifications or changes made by those skilled in the art on the basis of the technical solutions of the application without creative labor are still within the protection scope of the application.

Claims

1. A fire extinguishing system for a cable of a cable-stayed bridge, characterized in that The system comprises a fireproof water curtain system, a foam fire extinguishing system and a supply system. The fireproof water curtain system comprises water curtain nozzles arranged on one side or both sides of the cable in the width direction of the bridge deck, the water curtain nozzles spray water towards the top and the spray height is higher than a predetermined value; the foam fire extinguishing system comprises fire water guns arranged on the bridge deck. The supply system comprises a water pool and a foam tank, the water pool is communicated with the water curtain nozzles through a water curtain fire extinguishing pipe network, and the water pool and the foam tank are communicated with the fire water guns through a foam fire extinguishing pipe network. The water curtain nozzles on both sides of the cable are arranged towards the cable in the middle, forming a fireproof water curtain on one side or both sides of the cable, and the height of the fireproof water curtain is higher than a set value. An electromagnetic valve is arranged on the water curtain fire extinguishing pipe network in front of the water curtain nozzles, and the water curtain nozzles are controlled by the electromagnetic valve; when the electromagnetic valve near the fire is opened, the water curtain nozzles at the heated cable spray water to form a water curtain, the water curtain physically separates the fire source from the cable, and the purpose of fire blocking is achieved; at the same time, the scattered water wets the cable and cools the cable. When the fire is in the range of the cable, a fireproof water curtain is formed on both sides of the cable by the water curtain nozzles, the cable is blocked and cooled, at the same time, the fire water guns spray foam liquid to the fire source, so as to extinguish the fire; when the fire is not in the range of the cable, the fire water guns spray foam liquid to the fire source, so as to extinguish the fire. The supply system further comprises a pump house, the pump house is arranged on the ground, and an air conditioner or an electric heater is arranged in the pump house.

2. The fire extinguishing system for a cable of a cable-stayed bridge according to claim 1, wherein A water pool and a water pump are arranged in the pump house, the water pool is connected to the water curtain fire extinguishing pipe network through a water pipe, a check valve is arranged on the water pipe, a gate valve is arranged between the water pump and the check valve, and an electric control valve is arranged on the water curtain fire extinguishing pipe network in front of the water curtain nozzles.

3. The fire extinguishing system for a cable of a cable-stayed bridge according to claim 2, wherein A foam tank and a foam liquid pump are arranged in the pump house, the foam tank is connected to the foam fire extinguishing pipe network through a foam pipe, and a check valve is arranged on the foam pipe.

4. The fire extinguishing system for a cable of a cable-stayed bridge according to claim 3, wherein The water pipe and the foam pipe are connected to the inlet of a proportioning mixer, and the outlet of the proportioning mixer is connected to the foam fire extinguishing pipe network.

5. The fire extinguishing system for a cable of a cable-stayed bridge according to claim 4, wherein The system further comprises a control system, the control system comprises a detection unit and an automatic control center, the detection unit is signal connected with the automatic control center, and the automatic control center is signal connected with control elements in the pump house.

6. The fire extinguishing system for a cable of a cable-stayed bridge according to claim 2, wherein The detection unit is one or more of smoke detection, digital and image video monitoring, dangerous gas detection, infrared sensing detection and temperature sensing detection.

7. The fire extinguishing system for a cable of a cable-stayed bridge according to claim 6, wherein When the fire is in the range of the cable, a fireproof water curtain is formed on one side or both sides of the cable by the water curtain nozzles, the cable is blocked and cooled; at the same time, the fire water guns spray foam liquid to the fire source, so as to extinguish the fire.

8. A method of extinguishing fire using the fire extinguishing system for a cable of a cable-stayed bridge according to any one of claims 1 to 7, characterized in that, When the fire is not in the range of the cable, the fire water guns spray foam liquid to the fire source, so as to extinguish the fire. When the fire is over, the fire water guns are manually controlled to clean the contaminated bridge deck. ​ 9. The fire extinguishing method according to claim 8, wherein ​

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