Bridge cable fire resistant device and method using water

Abstract

The application discloses a kind of bridge cable fire resistance device with water, aiming at the problem that the fire prevention work of bridge cable in prior art still needs to be improved.The application comprises a plurality of fire resistance units connected along the cable;The cross section of the main body of the fire resistance unit is C-shaped, and surrounds the lower half ring surface of the cable from below the cable;The fire resistance unit is provided with a transverse fixing member that crosses the cable;The two ends of the fire resistance unit along the axial direction of the cable have matching water connectors;The fire resistance unit contains a water collection tank, and there is a soft water-absorbing cotton layer between the water collection tank and the cable that contacts both;The side of the fire resistance unit has water spray holes that spray water onto the upper surface of the cable.This technology can achieve spray cooling on the upper surface of the cable, and through the nozzle temperature control device at the end, different temperature control deformations are generated according to the temperature on the left and right sides or the upper side of the cable, thereby controlling the spray amount and spray coverage form at the nozzle of the flexible inner tube, and thus more accurately enhancing the cooling area and speed of the upper surface of the cable.

Description

Technical Field

[0001] This invention relates to the field of fire protection technology for bridge cables, and in particular to a water-based fire-resistant device and method for bridge cables. Background Technology

[0002] With the development of transportation and the advancement of technology, cable-stayed bridges and suspension bridges have become effective ways to cross rivers and valleys. A cable-stayed bridge, also known as a cable-stayed bridge, is a type of bridge where the main beam is directly supported by numerous cables to the bridge towers. It is a structural system composed of compression-bearing towers, tension-bearing cables, and bending-bearing beams. Essentially, it consists mainly of towers, main beams, and stay cables, and can be viewed as a multi-span elastically supported continuous beam where cables replace piers. This reduces bending moments within the beam, lowers the building height, reduces structural weight, and saves materials. Bridge cables play a supporting and reinforcing role in the bridge and are one of the most critical load-bearing components of cable-stayed bridges.

[0003] Statistically, the probability of accidents involving gasoline-powered vehicles is 0.01%-0.02%, and traffic fires occur approximately 0.5-1.5 times per 10 million kilometers of driving. The increase in vehicle ownership (exceeding 400 million in 2022) has increased the data sample size. Simultaneously, cable-stayed bridges, as crucial transportation infrastructure, experience increasing traffic volume year by year; statistics show that some cable-stayed bridges have peak daily traffic volumes exceeding 100,000 vehicles. Based on the probability statistics of this large data sample, fires on cable-stayed bridges have become almost inevitable.

[0004] The high temperatures following a fire will cause significant damage to the entire bridge structure, especially its cables. In particular, when a tanker truck catches fire, the rapid combustion, high flame temperature, and strong radiation—with temperatures at the flame center reaching 1400℃—lead to a substantial decrease in the elastic modulus and strength of the cable wires. Furthermore, it causes a redistribution of internal stress within the cables, making them more prone to breakage during a fire. Without timely rescue measures, the fire temperature will continue to rise, leading to partial or complete damage to the cable-stayed bridge. Engineering practice shows that while steel has good mechanical properties and promising applications, its fire resistance is poor. Generally, the tensile strength of cables is only significantly affected by temperature when the temperature is below 300℃. At 400℃, the mechanical properties of steel will rapidly decline, and at 600℃, the elastic modulus of steel will drop to half of that at room temperature. Bridges with steel structures as their main load-bearing components are highly susceptible to deformation and even collapse during a fire. When bridge cables are heated to a certain temperature, their strength and hardness decrease significantly, while their plasticity increases markedly, causing cable deformation and even bridge collapse. Once bridge cables fail or are damaged, it will trigger multiple disasters, resulting in very serious safety accidents and economic losses.

[0005] It takes at least 10 minutes for firefighters to arrive at the scene after a fire breaks out in a vehicle on a bridge, making fire protection for the cables essential. Existing cable protection methods focus on corrosion and vibration prevention, or simply modify the cable structure. For example, Chinese patent CN207259963U discloses a fire-resistant cable comprising a cable, an inner liner, a fire-resistant layer, and an outer liner, with a fire-resistant layer between the inner and outer liner. This fire-resistant layer is either a filler-type fire-retardant material or a fire-retardant coating. This cable only provides passive fire protection, and the increased cross-sectional area of ​​the cable leads to significant wind loads and cable vibrations. Its protective effectiveness is limited in the event of a major fire, and in remote areas or where firefighting is delayed, it can cause significant loss of life and property. Therefore, there is a need to design fire-resistant equipment for protecting the cables of existing bridges. This would be an additional fire-resistant measure on existing bridges, facilitating timely fire protection of the bridge cables by personnel at the fire scene and reducing damage to the cables caused by sudden fires. Summary of the Invention

[0006] This invention addresses the problem that fire protection for bridge cables still needs improvement in the existing technology by providing a water-based fire-resistant device and method for bridge cables that is structurally sound, has good fire protection effect, and is highly reliable.

[0007] The technical solution of the present invention is to provide a water-based bridge cable fire-resistant device with the following structure: comprising multiple fire-resistant units connected along the cable; the cross-section of the main body of the fire-resistant unit is C-shaped, surrounding the lower half of the cable from below; the fire-resistant unit is provided with a transverse fixing member that crosses the cable; the fire-resistant unit has matching water connectors at both ends along the cable axis; the fire-resistant unit contains a water collection tank, and a soft absorbent cotton layer in contact with both the water collection tank and the cable; the side of the fire-resistant unit has spray holes for spraying water onto the upper surface of the cable.

[0008] Preferably, the water spray holes are located on the upper surfaces of both sides of the water collection tank, with the openings of the water spray holes facing the cable side.

[0009] Preferably, the fire-resistant unit further includes a hot water absorption tank connected to the side of the water collection tank away from the cable. The hot water absorption tank and the water collection tank are separated by multiple support pillars and connected by a connecting conduit.

[0010] Preferably, the hot water tank has openings along both sides of the cable, and the openings are connected to a water spray assembly, with the nozzles of the water spray assembly facing the cable side.

[0011] Preferably, the water spray assembly includes a rigid metal outer tube and a positioning annular plate. The positioning annular plate is fitted onto the inner surface of one end of the metal outer tube and has multiple cooling holes. This end is fixedly connected to a hot water tank and communicates with its interior. A nozzle temperature control device is provided at the nozzle at the other end of the metal outer tube. The device includes a flexible inner tube, a flange, a fixing clamp, a heat-sensitive clamp, and bolts. The fixing clamp is fixed at the nozzle and is connected to the heat-sensitive clamp by bolts. The outlet end of the flexible inner tube is clamped between the fixing clamp and the heat-sensitive clamp. The inlet end of the flexible inner tube is fitted into the positioning annular plate through the flange. An arc-shaped compensator is provided on the inner surface of the fixing clamp or the heat-sensitive clamp, and the arc-shaped compensator is located in the middle of the compressed flexible inner tube.

[0012] Preferably, the inner side of the water collection tank is provided with multiple rows of water-storing baffles. The water-storing baffles are arc-shaped plates that separate the water-absorbing layers. The water-storing baffles are provided with multiple baffle through holes. The water-storing baffles are arc-shaped folded plates. The lowest point is the concave middle part of each water-storing baffle, and the highest points are the two upward ends. The water-storing baffles between the lowest and highest points are provided with multiple baffle through holes. Multiple rows of water-storing cotton strips are provided on one side of the water-storing baffles. The water-storing cotton strips are attached to the water-storing baffles or are sleeved on the outside of the water-storing baffles.

[0013] Preferably, the water connector includes a convex joint, a concave joint, and a sealing ring, wherein the convex joint is located on the lower end face of the water collection tank, the concave joint is located on the upper end face of the water collection tank, and the outer ring surface of the convex joint is provided with a sealing ring; the water collection tank is provided with a connecting pipe connecting the two ends of the water connector.

[0014] Preferably, the connecting pipe is equipped with a water valve, and the two ends of the connecting pipe away from the water valve and the water collection tank are respectively connected to the two ends of a straight pipe. The straight pipe is located in the gap between the water collection tank and the hot water absorption tank. The control shaft of the water valve extends out of the outer side of the hot water absorption tank and is vertically connected to the control handle. An extension cover is provided at the connection between the two hot water absorption tanks of adjacent fire-resistant units.

[0015] A method of using a bridge cable fire-resistant device that utilizes the aforementioned water includes the following steps:

[0016] Step 1: Under normal conditions, connect multiple fire-resistant units to the bottom of each cable on the cable-stayed bridge, fasten the fasteners, connect multiple fire-resistant units in series through water connectors, and seal the concave joint at the top of the uppermost fire-resistant unit; adjust the orientation of the fire-resistant unit so that its main body faces the direction of oncoming traffic on the bridge deck, as a vehicle collision protection device for the cable.

[0017] Step 2: If a fire occurs on the bridge deck, loosen the fasteners of the fire-resistant units on the affected cables so that the main body of the fire-resistant unit is below the cable. Open the water valve of the fire-resistant unit. Remove the fire-resistant units from the adjacent cables. Push the installed fire-resistant units upward along the affected cables and install the fire-resistant units removed from other cables. Open the water valve of the fire-resistant units. If the length of the installed fire-resistant units above is estimated to be greater than the length of the affected cable, close the water valve of the subsequent fire-resistant units. Continue until the upper fire-resistant unit is pushed to the predetermined height, isolating the flames from the cables.

[0018] Step 3: At the bottom of the cable, there is a connecting water pipe connected to the main water pipe laid along the main beam; connect the connecting water pipe to the lower end of the fire-resistant unit; open the water valve on the connecting water pipe to supply water to the multiple fire-resistant units connected in series; some water passes through the water collection tank and sprays out from the spray hole, splashing onto the upper surface of the cable, some of which evaporates, and some flows down from the upper surface into the water-absorbing layer; the water in the water-absorbing layer soaks into the lower surface of the cable opposite it and slowly flows down along the water-absorbing layer; or it enters the water-absorbing layer and the water-retaining baffles and water-retaining cotton strips above it, the water remaining in the water-retaining baffles soaks into the lower surface of the cable opposite it and slowly flows down; when the flame is more than 1 meter away from the cable in the horizontal direction, there is no direct flame. During roasting, the heat-sensitive plate in the nozzle temperature control device slightly controls the opening degree of the end of the flexible inner tube based on the relatively low temperature of the water flowing out of the outer metal tube, causing it to spray out a small amount of water. At the same time, a small amount of water will also spray out from the gap between the outer metal tube and the flexible inner tube, some of which evaporates and some flows from the upper surface to the lower surface. When the flame and the cable are less than 1 meter apart in the vertical direction, or when the flame directly roasts the cable, the heat-sensitive plate in the nozzle temperature control device controls the opening degree of the end of the flexible inner tube based on the higher temperature of the water flowing out of the outer metal tube, causing it to spray out a stronger and wider water flow. At the same time, a small amount of water will also spray out from the gap between the outer metal tube and the flexible inner tube, some of which evaporates and some flows from the upper surface to the lower surface.

[0019] Step 4: After the fire is extinguished, close the water valve on the connecting water pipe and disconnect the connecting water pipe. The water in the fire-resistant unit will flow by gravity. Starting from the bottom, remove the added fire-resistant units one by one. Disconnect the water connection between the fire-resistant units by loosening the fasteners. Install the removed fire-resistant units back onto the original cable.

[0020] Compared with the prior art, the water-based bridge cable fire-resistant device and method of the present invention has the following advantages:

[0021] 1. The fire-resistant unit provides shielding for the cable from the bottom and cools it with water. The upper surface of the cable is cooled by spraying water to achieve high-efficiency fire resistance.

[0022] 2. By utilizing the gaps between the cooling components, the cooling surface area of ​​the fire-resistant unit is increased. Furthermore, the conduit maximizes temperature isolation between the hot water tank and the collection tank, increasing the temperature difference between the water flowing within them during the fire-resistant process. This device effectively enhances fire resistance and reduces damage to bridge cables caused by sudden fires, providing fire protection for the bridge cables.

[0023] 3. The size and position of the perforations in the baffles near the cable can slow down the flow rate and storage state of water between the water storage baffles, so as to accumulate as much cold water as possible on the lower surface of the cable and ensure that the water has a longer residence time; the water storage baffles and / or water storage strips and / or absorbent layers can slow down the flow rate of water on the lower surface of the cable, change the flow area of ​​the water path, and the accumulated slow-flowing water is more likely to increase its contact area with the lower surface of the cable, so as to further play a reliable contact cooling role on the lower side of the cable.

[0024] 4. The water spray assembly can spray and cool the upper surface of the cable. Through the temperature control device of the nozzle at the end, different temperature control deformations are generated according to the temperature on the left and right sides or the upper side of the cable, thereby controlling the spray volume and spray coverage at the flexible inner tube nozzle, thus more accurately enhancing the cooling area and speed of the upper surface of the cable.

[0025] 5. When the heat-sensitive clamp is heated, it undergoes directional deformation, causing it to bulge relative to the fixed clamp. This reduces the clamping force between the two clamps on the opening at the end of the flexible inner tube, resulting in a larger opening at the end of the flexible inner tube and a larger water spray volume. The water output is automatically adjusted according to the temperature rise around the cable.

[0026] 6. For fire-resistant units that are far from the fire, water valves can be closed to conserve water and ensure that limited water resources are used where they are truly needed, thereby improving water use efficiency.

[0027] 7. The fire-resistant device can be standardized and modularized, and can be quickly assembled by a single person on site to provide timely protection for the cables. It is also easy to operate.

[0028] 8. The fire-resistant device can be used as a collision protection device for the cable during peacetime, and has multiple uses. Attached Figure Description

[0029] Figure 1 This is a schematic diagram illustrating the application scenario of the present invention;

[0030] Figure 2 This is one of the schematic cross-sectional views of the invention after it is installed with the cable.

[0031] Figure 3 This is the second schematic diagram of the cross-section of the invention after it is installed with the cable;

[0032] Figure 4This is the third schematic diagram of the cross-section of the invention after it is installed with the cable;

[0033] Figure 5 This is the present invention. Figure 4 Schematic diagram of the structure at point A (indicated by the Chinese character "A");

[0034] Figure 6 This is a top view schematic diagram of the segmented cooling device in this invention;

[0035] Figure 7 This is a bottom view of the straight pipe and water collection tank in this invention.

[0036] Figure 8 This is a side view of the straight pipe and water collection tank in this invention.

[0037] Figure 9 This is the present invention. Figure 8 A side view of the structure at point B (reference number B);

[0038] Figure 10 This is the present invention. Figure 9 A simplified cross-sectional view of section C-C';

[0039] Figure 11 This is the present invention. Figure 9 A schematic diagram of the cross-sectional structure at point C-C';

[0040] Figure 12 This is one of the side view structural schematic diagrams of the water storage baffle and water storage cotton strip in this invention;

[0041] Figure 13 This is the present invention. Figure 12 A schematic diagram of the cross-sectional structure at point D-D';

[0042] Figure 14 This is the second side view schematic diagram of the water storage baffle and water storage cotton strip in this invention;

[0043] Figure 15 This is the present invention. Figure 14 A schematic diagram of the cross-sectional structure at point E-E';

[0044] Figure 16 This is one of the top view schematic diagrams of the water-retaining baffle and water-retaining cotton strip in this invention;

[0045] Figure 17 This is the second top view schematic diagram of the water-retaining baffle and water-retaining cotton strip in this invention;

[0046] Figure 18 This is a side view of the absorbent cotton structure in this invention;

[0047] Figure 19 This is a schematic diagram of the nozzle temperature control device in this invention;

[0048] Figure 20 This is the present invention. Figure 19 A schematic diagram of the cross-sectional structure at point F-F';

[0049] Figure 21 This is the present invention. Figure 20 One of the structural schematic diagrams at point G;

[0050] Figure 22 This is the present invention. Figure 20 The second structural schematic diagram at point G (marked in Chinese);

[0051] Figure 23 This is a side view of the thermal clamp structure in this invention;

[0052] Figure 24 This is a top view of the thermal clamp structure in this invention.

[0053] In the attached diagram, number 1 represents a single-column pier cable-stayed bridge, and 2 represents a fire prevention device. 1-1 is a single-column pier, 1-2 is a cable, 1-3 is the bridge deck; 2-1 is a hot water tank, 2-2 is a conduit, 2-3 is a water collection tank, 2-4 is a water storage baffle, 2-5 is a water storage cotton strip, 2-6 is a male connector, 2-6' is a female connector, 2-7 is a hook, 2-8 is a water spray assembly, 2-9 is a nozzle temperature control device, 2-10 is a fixing strip, 2-11 is a baffle perforation, 2-12 is a straight pipe, and 2-13 is a water valve. 2-14 is an extension baffle, 2-15 is a notch, 2-16 is an absorbent cotton layer, and 2-17 is a connecting pipe; 2-8-1 is a metal outer tube, 2-8-2 is a flange, 2-8-3 is a positioning ring plate, 2-8-4 is a cooling through hole, and 2-8-5 is a flexible inner tube; 2-9-1 is a bolt, 2-9-2 is a heat-sensitive clamping plate, 2-9-3 is a fixing clamping plate, 2-9-4 is an arc-shaped compensator, and 2-9-5 is an elongated hole. Detailed Implementation

[0054] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0055] The fire-resistant device and method for bridge cables using water, as described below with reference to the accompanying drawings and specific embodiments, are further explained below: This embodiment is widely applicable to bridges with small spans in river valleys and using single-column piers 1-1, because they have the disadvantage that a vehicle on fire on the bridge deck 1-3 will burn its cables 1-2.

[0056] like Figure 2 As shown, Embodiment 1 includes multiple fire-resistant units connected along cable 1-2; the cross-section of the main body of the fire-resistant unit is C-shaped, surrounding cable 1-2 from the lower part; the upper half of the fire-resistant unit is provided with a transverse fixing member that crosses cable 1-2; the fire-resistant unit contains a water collection tank 2-3; the water collection tank 2-3 is hollow and close to cable 1-2, with its inner side surrounding the outer ring surface of the lower part of cable 1-2, and water connectors are provided at both ends of the water collection tank 2-3 along the axial direction of cable 1-2.

[0057] like Figure 3 As shown, Embodiment 2 includes multiple fire-resistant units connected along cable 1-2; the cross-section of the main body of the fire-resistant unit is C-shaped, surrounding cable 1-2 from the lower part; the upper half of the fire-resistant unit is provided with a transverse fixing member that crosses cable 1-2; the fire-resistant unit includes a water-absorbing tank 2-1 and a water-collecting tank 2-3; the water-collecting tank 2-3 is hollow and close to cable 1-2, with its inner side surrounding the outer ring surface of the lower part of cable 1-2; the water-absorbing tank 2-1 is located on the side of the water-collecting tank 2-3 away from cable 1-2, and the lower side of the water-collecting tank 2-3 is connected to the water-absorbing tank 2-1; water connectors are provided at both ends of the fire-resistant unit along the axial direction of cable 1-2. Openings are provided on both sides of the water-absorbing tank 2-1 along cable 1-2, facing the cable 1-2 side, to facilitate water inside the water-absorbing tank 2-1 spraying onto the upper surface of cable 1-2.

[0058] like Figure 4 As shown, Embodiment 3 includes multiple fire-resistant units connected along cable 1-2; the cross-section of the main body of the fire-resistant unit is C-shaped, surrounding cable 1-2 from the lower part; the upper half of the fire-resistant unit is provided with a transverse fixing member that crosses cable 1-2; the fire-resistant unit includes a water-absorbing tank 2-1 and a water-collecting tank 2-3; the water-collecting tank 2-3 is hollow and close to cable 1-2, with its inner side surrounding the outer ring surface of the lower part of cable 1-2; the water-absorbing tank 2-1 is located on the side of the water-collecting tank 2-3 away from cable 1-2, and the lower side of the water-collecting tank 2-3 is connected to the water-absorbing tank 2-1; water connectors are provided at both ends of the fire-resistant unit along the axial direction of cable 1-2. Openings are provided on both sides of the water-absorbing tank 2-1 along cable 1-2, and a water spray assembly 2-8 is connected through these openings; the nozzle openings of the water spray assembly 2-8 face the upper surface of cable 1-2.

[0059] The water collection tank 2-3 is surrounded and / or attached to the lower surface of the cable 1-2. The internal cavity can supply cold water, and multiple rows of radially spaced water storage baffles 2-4 can be arranged on the inner ring surface on the upper outer side.

[0060] The heat-absorbing tank 2-1 is the outermost tank that prevents the lower surface of the cable 1-2 from being directly scorched by the fire. It is the main heat-absorbing component. It is connected to the cold water collection tank 2-3 by multiple dispersed conduits 2-2, connecting the outermost heat-absorbing tank 2-1 that prevents the cable 1-2 from being scorched and the water collection tank 2-3 on the lower surface of the cable 1-2. The three are interconnected by a certain number of conduits 2-2. The conduits 2-2 can maximize the temperature isolation between the heat-absorbing tank 2-1 and the water collection tank 2-3, with water flowing from the lower temperature area to the higher temperature area, increasing the temperature difference between the water inside the two tanks during the fire-fighting process.

[0061] The inner annular surface of the hot water tank 2-1 is provided with multiple rows of water-retaining baffles 2-4. Each baffle 2-4 is an arc-shaped plate with multiple through holes 2-11. The baffle 2-4 is also an arc-shaped folded plate, with the lowest point being the concave center and the highest points being the upward ends. Multiple through holes 2-11 are located on the baffle 2-4 between the lowest and highest points. One side of each baffle 2-4 is provided with multiple rows of water-retaining cotton strips 2-5. These strips can be fitted directly to the baffle 2-4, sleeved on the outside of the baffle 2-4, or the baffle 2-4 can be omitted, and the entire strip can be used as a water-absorbing cotton layer 2-16. All three configurations achieve water retention on the inner annular surface of the hot water tank 2-1 and reliably cool the lower surface of the cable 1-2.

[0062] The size and position of the openings in the baffle 2-11 can also slow down the flow rate and storage state of water between the water storage baffles 2-4, so as to accumulate as much cold water as possible on the lower surface of the cable 1-2 and ensure a relatively thorough circulation from top to bottom. Without the baffle 2-11, the water sprayed down from the upper surface of the cable 1-2 would not easily replace the water between the lower surface of the cable 1-2 and the water storage baffles 2-4, and the water between the inclined water collection tank 2-3 and the water storage baffles 2-4 would accumulate and not circulate, weakening the effect of the cooling water. The water storage baffles 2-4 can slow down the residence time and residence state of water on the wall of the water collection tank 2-3 on the lower surface of the cable 1-2, reduce its downward flow speed on the lower surface of the cable 1-2, increase the contact area between the accumulated water and the lower surface of the cable 1-2, and achieve reliable contact cooling on the lower side. Water-retaining cotton strips 2-5 can further slow down the flow rate of water on the lower surface of cable 1-2, change the flow area of ​​the water channel, and the accumulated slow-flowing water is more likely to increase its contact area with the lower surface of cable 1-2, thus providing reliable contact cooling on the lower side of cable 1-2.

[0063] Alternatively, a soft absorbent layer can be directly installed on the inner annular surface of the hot water tank 2-1 to facilitate water storage and moisture retention, while also achieving reliable cooling.

[0064] The upper part of the fire-resistant unit is equipped with a transverse fixing component for the upper cable 1-2. The fixing component includes hooks 2-7 and fixing strips 2-10 set on both sides of the water collection tank 2-3. The hooks 2-7 and fixing strips 2-10 can act as a clamp, wrapping around and overlapping the upper surface of the cable 1-2, and wrapping the water collection tank 2-3 around and overlapping the lower surface of the cable 1-2. The upper surface of the water collection tank 2-3 can be tightly attached to or not tightly attached to the lower surface of the cable 1-2, and gaps are allowed. The gaps allow water to flow down through the layers of water storage baffles 2-4. If you want to control the flow rate of the water, you can add water storage cotton strips 2-5 near the water storage baffles 2-4 to slow down the flow rate of the water. The water storage cotton strips 2-5 can be made of sponge material, and water storage cotton strips 2-5 of different thicknesses will produce different water flow resistance.

[0065] Without gaps, water can flow downwards through the perforations 2-11 on the layered water storage baffles 2-4. The flow rate is controlled by the size and number of the perforations 2-11. Alternatively, water-retaining cotton strips 2-5 can be added near the water storage baffles 2-4 to slow down the downward flow of water. The water-retaining cotton strips 2-5 can be made of sponge material, and different thicknesses of water-retaining cotton strips 2-5 will produce different water flow resistance.

[0066] The water spray assembly 2-8 includes a rigid metal outer tube 2-8-1 and a positioning annular plate 2-8-3. The positioning annular plate 2-8-3 is sleeved on the inner surface of one end of the metal outer tube 2-8-1. The positioning annular plate 2-8-3 has multiple cooling through holes 2-8-4. This end is fixedly connected to the hot water tank 2-1 and communicates with its interior. A nozzle temperature control device 2-9 is provided at the nozzle at the other end of the metal outer tube 2-8-1, which includes a flexible inner tube 2-8-. 5. Flange 2-8-2, fixing clamp 2-9-3, thermal clamp 2-9-2 and bolt 2-9-1. The fixing clamp 2-9-3 is fixed at the nozzle and is connected to the thermal clamp 2-9-2 by bolt 2-9-1. The outlet end of the flexible inner tube 2-8-5 is clamped between the fixing clamp 2-9-3 and the thermal clamp 2-9-2. The inlet end of the flexible inner tube 2-8-5 is sleeved in the positioning ring plate 2-8-3 through the flange 2-8-2.

[0067] The water spray assembly 2-8 can spray and cool the upper surface of the cable 1-2. Through the nozzle temperature control device 2-9 at the end, different temperature control deformations are generated according to the temperature on the left and right sides or the upper side of the cable 1-2, thereby controlling the spray volume and spray coverage at the nozzle of the flexible inner tube 2-8-5, thus more accurately enhancing the cooling area and speed of the upper surface of the cable 1-2.

[0068] The outer metal tube 2-8-1 serves to shape and constrain the orientation of the flexible inner tube 2-8-5. The positioning annular plate 2-8-3 has cooling through holes 2-8-4 and a central hole. One end of the flexible inner tube 2-8-5 has a flange 2-8-2 that fits into the central hole. The other end of the flexible inner tube 2-8-5 is connected to the nozzle temperature control device 2-9 at the end of the outer metal tube 2-8-1. The central hole ensures that the flexible inner tube 2-8-5 and the high-temperature outer metal tube 2-8-1 are concentric with minimal or no contact. Even if the bend of the flexible inner tube 2-8-5 comes into contact with the heated outer metal tube 2-8-1, it will not be damaged by the heat. This is because the water flow between the flexible inner tube 2-8-5 and the surrounding high-temperature outer metal tube 2-8-1 can significantly reduce the temperature of the outer metal tube 2-8-1, and further prevents the flexible inner tube 2-8-5 from bending due to excessive thermal expansion.

[0069] The annular cavity between the outer metal tube 2-8-1 and the flexible inner tube 2-8-5 is connected sequentially to the hot water tank 2-1, the conduit 2-2, and the collection tank 2-3 via cooling through holes 2-8-4 on the positioning annular plate 2-8-3. Therefore, water will continuously flow out of the outer metal tube 2-8-1 within the annular cavity. The water flow rate can be preset after multiple experiments to determine the total area of ​​the cooling through holes 2-8-4. A portion of the outflowing water will flow onto the nozzle temperature control device 2-9, preventing it from being damaged by high temperatures. The interior of the outer metal tube 2-8-1 is interconnected with the hot water tank 2-1 via holes on the positioning annular plate 2-8-3. This flowing water prevents the flexible inner tube 2-8-5 from being damaged by the high temperatures of the outer metal tube 2-8-1. One end of the flexible inner tube 2-8-5 is sleeved on the middle of the positioning ring plate 2-8-3 through the flange 2-8-2. This not only enables the water circuit between the flexible inner tube 2-8-5 and the water absorption tank 2-1, but also positions one end of the flexible inner tube 2-8-5 to prevent the flexible inner tube 2-8-5 from deforming and obstructing the smooth flow of water.

[0070] If the diameter of the outer metal tube 2-8-1 is slightly larger than that of the flexible inner tube 2-8-5, the water in the hot water tank 2-1 will first absorb heat and then flow out through the gap between the outer metal tube 2-8-1 and the flexible inner tube 2-8-5. During the outflow process, it can also absorb some of the heat from the heated outer metal tube 2-8-1, and the temperature of the water that finally flows out will be raised to a certain extent.

[0071] If, during the design phase, it is undesirable for the water flowing out of the gap between the outer metal tube 2-8-1 and the flexible inner tube 2-8-5 to experience excessive temperature rise, the cooling water supply rate and the diameter of the outer metal tube 2-8-1 need to be adjusted. However, an excessively high cooling water supply rate can lead to water waste, as the time from ignition to the end of firefighting can be long, or the fire intensity can fluctuate, resulting in an uncertain water consumption. Conversely, an excessively low water flow rate will reduce the amount of water sprayed onto the upper surface of the cable 1-2. Therefore, the water flow rate can be adjusted by the operator according to the fire intensity, adjusting the water supply pressure accordingly.

[0072] During normal use, water continuously flows out from the gap between the outer metal tube 2-8-1 and the flexible inner tube 2-8-5, eventually splashing onto the upper surface of the cable 1-2 and then dispersing. The end of the flexible inner tube 2-8-5, held by the positioning ring plate 2-8-3 and the heat-sensitive clamping plate 2-9-2, sprays cooling water through a thin slit, achieving a large cooling coverage area. After spraying, the water spreads on the upper surface of the cable 1-2, and then flows downwards, forming a better arc-shaped cooling surface.

[0073] When the fire intensifies or gradually increases in a harsh environment, the temperature of the water inside the metal outer tube 2-8-1 will rise under the intense heat. When the temperature rises from room temperature to between 60 degrees Celsius and its boiling point, the slightly warmer water will deform and increase in length after passing through the heat-sensitive clamp 2-9-2 or after the heat-sensitive clamp 2-9-2 is heated by the high temperature.

[0074] The heat-sensitive clamp 2-9-2 here is a bimetallic sheet composed of a tightly bonded iron plate and an aluminum plate. Under high temperature, the aluminum plate is pressed onto the iron plate. When heated, the two materials expand and contract differently, resulting in directional deformation. This deformation requires the heat-sensitive clamp 2-9-2 to bulge relative to the fixing clamp 2-9-3. This reduces the clamping tightness between them at the opening of the flexible inner tube 2-8-5, thus increasing the opening at the end of the flexible inner tube 2-8-5 and consequently increasing the water spray volume.

[0075] Bimetallic strips, also known as thermal bimetallic strips, are typically composed of two different metals, such as iron and aluminum, or steel and molybdenum. Due to the different coefficients of thermal expansion of each component layer, internal stress causes the bimetallic strip to bend or twist when the temperature changes. The deformation of the active layer is greater than that of the passive layer, causing the entire bimetallic strip to bend towards the passive layer. This change in the curvature of the composite material results in deformation. Bimetallic strips are commonly used in mechanical equipment such as thermometers, differential thermometers, and automatic controllers. The layer with the higher coefficient of thermal expansion is called the active layer; the layer with the lower coefficient of thermal expansion is called the passive layer. To obtain accurate deflection, the operating temperature needs to be within the linear operating range of the bimetallic strip, meaning that the increase in operating temperature and the deflection of the bimetallic strip have a typical linear relationship. For example, a bimetallic strip with a linear temperature range of -20 to 200°C will exhibit a curved curve above 200°C, no longer showing a linear relationship.

[0076] The fixing clamp 2-9-3 is fixed to the end of the metal outer tube 2-8-1. After mating with the heat-sensitive clamp 2-9-2, the two are fixed together by two bolts 2-9-1. The opening at the end of the flexible inner tube 2-8-5 is clamped between them, serving as its positioning and function. The two positioning holes on the heat-sensitive clamp 2-9-2 are rectangular or rounded rectangles. The bolts 2-9-1 are used to clamp and position it with the fixing clamp 2-9-3, but they do not need to be tightened too much. This ensures that the heat-sensitive clamp 2-9-2 can deform by bulging between the two bolts 2-9-1 after being heated. Tightening the bolts 2-9-1 too much will not be conducive to the deformation of the heat-sensitive clamp 2-9-2. Under the clamping of the positioning ring plate 2-8-3 and the heat-sensitive clamp plate 2-9-2, more cooling water will be sprayed out through the slightly enlarged slit, achieving a larger cooling coverage area and a greater degree of temperature reduction. After spraying, the water will also spread on a larger surface area of ​​the cable 1-2, ultimately fully cooling the upper surface of the cable 1-2.

[0077] If the nozzle temperature control device 2-9 activates its temperature control function under the scorching heat of high-temperature air waves or during contact with high-temperature cooling water, the sprayed water flow will increase. At this time, the temperature rise of the upper surface of cable 1-2 will also intensify, and more cooling water will be sprayed and spread on its upper surface to achieve cooling and prevent the temperature rise of the upper and lower surfaces of cable 1-2 from becoming too high.

[0078] An arc-shaped compensator 2-9-4 is provided on the inner side of the fixed clamping plate 2-9-3 or the heat-sensitive clamping plate 2-9-2, and the arc-shaped compensator 2-9-4 is located in the middle of the extruded flexible inner tube 2-8-5.

[0079] The curved compensator 2-9-4 is the bulge in the middle of the heat-sensitive clamp 2-9-2. Because it is not compensated, the movement of the middle part of the heat-sensitive clamp 2-9-2 is greater than that of the two ends and it is more sensitive to deformation. It is highly likely that the middle part will be more upturned. If there is no curved compensator 2-9-4 in the middle, the shape of the opening at the end of the flexible inner tube 2-8-5 will be close to the shape of a date pit, rather than a narrow rectangle, which will result in uneven water spray and further reduce the spray intensity of water at the opening.

[0080] The flexible inner tube 2-8-5 is made of silicone, with a maximum temperature resistance of approximately 350 degrees Celsius. Ordinary silicone has a high-temperature resistance between 200 and 300 degrees Celsius, but some special silicones can withstand temperatures up to approximately 350 degrees Celsius for a short period of two hours. The flexible inner tube 2-8-5 adjusts the size of the outermost end gap by tightening the clamp at its end opening, thus regulating the water spray volume.

[0081] The water connector includes a convex connector 2-6, a concave connector 2-6', and a sealing ring. The convex connector 2-6 is located on the lower end face of the water collection tank 2-3, and the concave connector 2-6' is located on the upper end face of the water collection tank 2-3. The outer ring surface of the convex connector 2-6 is provided with a sealing ring. Connecting pipes 2-17 are provided on both sides of the water collection tank 2-3 to connect the water connectors at both ends.

[0082] Additionally, a water valve 2-13 may be installed on the connecting pipe 2-17. The two ends of the connecting pipe 2-17 away from the water valve 2-13 and the water collection tank 2-3 are respectively connected to the two ends of the straight pipe 2-12. The straight pipe 2-12 is located in the gap between the water collection tank 2-3 and the hot water absorption tank 2-1. The control shaft of the water valve 2-13 extends out of the outer side of the hot water absorption tank 2-1 and is vertically connected to the control handle. An extension cover 2-14 is provided at the connection between the two hot water absorption tanks 2-1 of adjacent fire-resistant units.

[0083] The outer surface of the male connector 2-6 is equipped with a rubber gasket, which allows for quick mating with the female connector 2-6'. Furthermore, the water inside the water collection tank 2-3, combined with the weight of the previous water collection tank 2-3, compresses the water more tightly. The female connector 2-6' works with the male connector 2-6 to connect the water channels, and the rubber gasket provides a reliable seal between the male connector 2-6 and the female connector 2-6'.

[0084] The water flow path in the two water collection tanks 2-3 is as follows: after passing through the lower water collection tank 2-3, the connecting pipe 2-17 on the upper side of the lower water collection tank 2-3, the convex joint 2-6, the concave joint 2-6', and the connecting pipe 2-17 on the lower side of the higher water collection tank 2-3, it reaches the higher water collection tank 2-3, and then flows in a cycle to the highest water collection tank 2-3. The connecting pipe 2-17 on the upper side of the highest water collection tank 2-3 needs to be sealed with a plug.

[0085] The lower side of the water collection tank 2-3 is connected to the hot water absorption tank 2-1 through two or more pipes 2-2 and separated by multiple support pillars. The control rod of the water valve 2-13 extends out of the outer side of the hot water absorption tank 2-1.

[0086] If it is considered that water spraying can be stopped at fire-resistant devices not exposed to large fires, thus saving water and extending the water flow protection time, a water valve 2-13 can be installed on each connecting pipe 2-17 near the water collection tank 2-3 to control whether water can enter the water collection tank 2-3 through the connecting pipes 2-17 on the upper and lower sides. In addition, a straight pipe 2-12 needs to be installed on each water collection tank 2-3 near the water connector of the connecting pipe 2-17. The straight pipe 2-12 passes through the gap between the water collection tank 2-3 and the hot water absorption tank 2-1. The control shaft of the water valve 2-13 needs to extend beyond the outer side of the hot water absorption tank 2-1, otherwise it will be inconvenient for the operator to rotate it. After installing a rotating handle on the outside, an extension baffle 2-14 can be added at the connection between two pairs of hot water absorption tanks 2-1 to minimize the risk between the two pairs of hot water absorption tanks 2-1 and prevent high-temperature air waves from causing local damage to the cable 1-2 through the gap. In areas far from the fire, the opening of water valve 2-13 can be adjusted to prevent water from flowing into water collection tank 2-3. Instead, water flows directly away through the straight pipe 2-12 between the lower annular surface of water collection tank 2-3 and the inner annular surface of hot water absorption tank 2-1. This ensures sufficient water pressure near the heated cable 1-2, while preventing excessive water loss and waste near the unheated cable 1-2.

[0087] A method of using the above-mentioned water-based fire-resistant device for bridge cables 1-2 includes the following steps:

[0088] Step 1: Under normal conditions, connect multiple fire-resistant units to the bottom of each cable 1-2 on the cable-stayed bridge, fasten the fasteners, and connect multiple fire-resistant units in series through water connectors to seal the concave joint 2-6' at the top of the uppermost fire-resistant unit; adjust the orientation of the fire-resistant unit so that its main body faces the oncoming traffic direction of the bridge deck 1-3, as a vehicle collision protection device for cable 1-2.

[0089] Step 2: If a fire occurs on bridge deck 1-3, loosen the fasteners of the existing fire-resistant units on the fire-affected cable 1-2 so that the main body of the fire-resistant unit is below the cable 1-2. Open the water valve 2-13 of the fire-resistant unit. Remove the fire-resistant units from the adjacent cables 1-2. Push the installed fire-resistant units upward along the fire-affected cable 1-2, install the fire-resistant units removed from other cables 1-2, and open the water valve 2-13 of the fire-resistant units. If the length of the installed fire-resistant units above is estimated to be greater than the length of the cable 1-2 affected by the fire, close the water valve 2-13 of the subsequent fire-resistant units. Continue until the fire-resistant units at the top are pushed to the predetermined height, isolating the flames from the cable 1-2.

[0090] Step 3: At the bottom of cable 1-2, there is a connecting water pipe connected to the main water pipe laid along the main beam; connect the connecting water pipe to the lower end of the fire-resistant unit 2-6; open the water valve 2-13 on the connecting water pipe to supply water to the multiple fire-resistant units connected in series; after the water passes through the hot water tank 2-1, it is sprayed out from the nozzle temperature control device 2-9 located at the opening above cable 1-2 of the water spray assembly 2-8. The water is sprayed onto the upper surface of cable 1-2, part of which evaporates and part flows down from the upper surface, and then slowly flows through the water storage baffle 2-4 and / or water storage cotton strip 2-5 on the inner side of the water collection tank 2-3, and soaks the lower surface of cable 1-2 opposite to it;

[0091] When the flame is more than 1 meter away from the cable 1-2 in the horizontal direction and there is no direct heat from the flame, the heat-sensitive clamp 2-9-2 in the nozzle temperature control device 2-9 slightly controls the opening degree of the end of the flexible inner tube 2-8-5 according to the low temperature water flowing out of the metal outer tube 2-8-1, so that a small amount of water is sprayed out. At the same time, a small amount of water will also be sprayed out from the gap between the metal outer tube 2-8-1 and the flexible inner tube 2-8-5. Part of it evaporates and part of it flows from the upper surface to the lower surface.

[0092] When the flame and cable 1-2 are less than 1 meter apart in the vertical direction, or when the flame directly heats the cable 1-2, the heat-sensitive plate 2-9-2 in the nozzle temperature control device 2-9 controls the opening degree of the end of the flexible inner tube 2-8-5 according to the water with a higher temperature flowing out of the metal outer tube 2-8-1, so that it sprays out a stronger and wider water flow. At the same time, a small amount of water will also be sprayed out from the gap between the metal outer tube 2-8-1 and the flexible inner tube 2-8-5. Part of it evaporates and part of it flows from the upper surface to the lower surface.

[0093] Step 4: After the fire is extinguished, close the water valve 2-13 on the connecting water pipe and disconnect the connecting water pipe. The water in the fire-resistant unit will flow by gravity. Starting from the bottom, remove the added fire-resistant units one by one. Specifically, disassemble the water connectors between the fire-resistant units and loosen the fasteners. Reinstall the removed fire-resistant units back onto the original cable 1-2.

[0094] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A water-based bridge cable fire-resistant device, characterized in that: The system comprises multiple fire-resistant units connected along a cable. The main body of each fire-resistant unit has a C-shaped cross-section, encircling the lower half of the cable's surface from below. Each fire-resistant unit has a transverse fixing member that crosses the cable. Each fire-resistant unit has matching water connectors at both ends along the cable's axial direction. Each fire-resistant unit contains a water collection tank, with a soft, absorbent cotton layer in contact with both the water collection tank and the cable. The sides of each fire-resistant unit have spray holes for spraying water onto the upper surface of the cable. Each fire-resistant unit also includes a hot water tank connected to the water collection tank on the side away from the cable. The hot water tank and the water collection tank are separated by multiple supports and connected by a connecting conduit. The hot water tank has openings along both sides of the cable, and these openings are connected to a water spray assembly. The nozzles of the water spray assembly face the cable side. The water spray assembly includes a rigid metal outer tube and a positioning annular plate. The positioning annular plate is fitted onto the inner surface of one end of the metal outer tube. The positioning annular plate has multiple cooling through holes, the ends of which are fixedly connected to the hot water tank and the hot water... The interior of the box is interconnected; a nozzle temperature control device is provided at the nozzle at the other end of the metal outer tube, which includes a flexible inner tube, a flange, a fixed clamp, a thermosensitive clamp, and bolts. The fixed clamp is fixed at the nozzle and is connected to the thermosensitive clamp by bolts. The water outlet end of the flexible inner tube is clamped between the fixed clamp and the thermosensitive clamp. The water inlet end of the flexible inner tube is sleeved in the positioning ring plate through the flange. An arc-shaped compensator is provided on the inner side of the fixed clamp or the thermosensitive clamp, and the arc-shaped compensator is located in the middle of the compressed flexible inner tube. The inner side of the water collection tank is provided with multiple rows of water storage baffles. The water storage baffles are arc-shaped plates that separate the water absorption layers. The water storage baffles are provided with multiple baffle through holes. The water storage baffles are arc-shaped folded plates. The lowest point is the concave middle part of each water storage baffle, and the highest point is the two upward ends. The water storage baffle between the lowest and highest points is provided with multiple baffle through holes. One side of the water storage baffles is provided with multiple rows of water storage cotton strips, wherein the water storage cotton strips are attached to the water storage baffles or are sleeved on the outside of the water storage baffles.

2. The water-cooled bridge cable fire-resistant device according to claim 1, characterized in that: The water spray holes are located on the upper surfaces of both sides of the water collection tank, with the openings of the water spray holes facing the cable side.

3. The water-cooled bridge cable fire-resistant device according to claim 1, characterized in that: The water connector includes a convex connector, a concave connector, and a sealing ring. The convex connector is located on the lower end face of the water collection tank, and the concave connector is located on the upper end face of the water collection tank. The outer ring surface of the convex connector is provided with a sealing ring. The water collection tank is provided with a connecting pipe to connect the two ends of the water connector.

4. The water-cooled bridge cable fire-resistant device according to claim 3, characterized in that: The connecting pipe is equipped with a water valve. The two ends of the connecting pipe away from the water valve and the water collection tank are respectively connected to the two ends of the straight pipe. The straight pipe is located in the gap between the water collection tank and the hot water absorption tank. The control shaft of the water valve extends out of the outer side of the hot water absorption tank and is vertically connected to the control handle. An extension cover is provided at the connection between the two hot water absorption tanks of adjacent fire-resistant units.

5. A method of using a water-based bridge cable fire-resistant device as described in claim 1, characterized in that: It includes the following steps, Step 1: Under normal conditions, connect multiple fire-resistant units to the bottom of each cable on the cable-stayed bridge, fasten the fasteners, connect multiple fire-resistant units in series through water connectors, and seal the concave joint at the top of the uppermost fire-resistant unit; adjust the orientation of the fire-resistant unit so that its main body faces the direction of oncoming traffic on the bridge deck, as a vehicle collision protection device for the cable. Step 2: If a fire occurs on the bridge deck, loosen the fasteners of the fire-resistant units on the cables affected by the fire, so that the main body of the fire-resistant unit is located below the cables, and open the water valve of the fire-resistant unit. Remove the fire-resistant unit from the adjacent cable; push the installed fire-resistant unit upward along the cable affected by the fire, install the fire-resistant unit removed from the other cables, and open the water valve of the fire-resistant unit; If the length of the fire-resistant unit already installed above is estimated to be greater than the length of the cable affected by the disaster, shut off the water valves of the subsequent fire-resistant units; until the upper fire-resistant unit is pushed to the predetermined height to isolate the flames and the cable. Step 3: At the bottom of the cable, there is a connecting water pipe connected to the main water pipe laid along the main beam; connect the connecting water pipe to the lower end of the fire-resistant unit; open the water valve on the connecting water pipe to supply water to the multiple fire-resistant units connected in series; some water passes through the water collection tank and sprays out from the spray hole, splashing onto the upper surface of the cable, some of which evaporates, and some flows down from the upper surface into the water-absorbing layer; the water in the water-absorbing layer soaks into the lower surface of the cable opposite it and slowly flows down along the water-absorbing layer; or it enters the water-absorbing layer and the water-retaining baffles and water-retaining cotton strips above it, the water remaining in the water-retaining baffles soaks into the lower surface of the cable opposite it and slowly flows down; when the flame is more than 1 meter away from the cable in the horizontal direction, there is no direct flame. During roasting, the heat-sensitive plate in the nozzle temperature control device slightly controls the opening degree of the end of the flexible inner tube based on the relatively low temperature of the water flowing out of the outer metal tube, causing it to spray out a small amount of water. At the same time, a small amount of water will also spray out from the gap between the outer metal tube and the flexible inner tube, some of which evaporates and some flows from the upper surface to the lower surface. When the flame and the cable are less than 1 meter apart in the vertical direction, or when the flame directly roasts the cable, the heat-sensitive plate in the nozzle temperature control device controls the opening degree of the end of the flexible inner tube based on the higher temperature of the water flowing out of the outer metal tube, causing it to spray out a stronger and wider water flow. At the same time, a small amount of water will also spray out from the gap between the outer metal tube and the flexible inner tube, some of which evaporates and some flows from the upper surface to the lower surface. Step 4: After the fire is extinguished, close the water valve on the connecting water pipe and disconnect the connecting water pipe. The water in the fire-resistant unit will flow by gravity. Starting from the bottom, remove the added fire-resistant units one by one. Disconnect the water connection between the fire-resistant units by loosening the fasteners. Install the removed fire-resistant units back onto the original cable.

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