Cable-stayed bridge main tower fire-fighting early warning system and working method thereof

Abstract

The invention relates to a cable-stayed bridge main tower fire-fighting early warning system and a working method thereof, and relates to the field of construction safety, the cable-stayed bridge main tower fire-fighting early warning system comprises a main water tank, an auxiliary water tank, water bags, sprayers and a water gun, a frame body is installed on the outer side wall of the top layer of a main tower, the auxiliary water tank is hung on the adjacent outer side wall of the main tower below a climbing frame, and the water bags are placed on the frame body around the main water tank; the multiple nozzles are fixedly connected to the top in the frame body at intervals, one ends of the multiple water guns are connected with the water bag through the water pump, the other ends of the water guns are bound to the frame body, and the large-height main tower construction safety protection device has the advantage that high safety protection can be achieved for large-height main tower construction.

Description

Technical Field

[0001] This invention relates to the field of construction safety technology, and in particular to a fire early warning system for the main tower of a cable-stayed bridge and its working method. Background Technology

[0002] During high-altitude welding and cutting operations on cable-stayed bridge towers, the presence of numerous materials in the work area poses a significant risk of ignition, potentially causing fires. Firstly, workers focused on their tasks may struggle to visually detect fires initially, and conventional construction methods often lack the capacity to deploy fire-fighting water to the high-altitude towers. The construction unit is only equipped with a limited number of fire extinguishers, which are insufficient to extinguish developing fires promptly, increasing the risk of construction fires. Secondly, the complex environment at heights, coupled with prolonged exposure to hot and humid conditions, can cause aging and failure of fire-fighting pipes and conduits, leading to leaks and malfunctions in the water supply system, further compromising fire safety. Strong winds and earthquakes can also damage the pipe structure, reducing system stability. Furthermore, traditional methods often fail to accurately pinpoint the cause of a fire, hindering targeted warnings for subsequent construction and leading to recurring safety hazards that hinder fundamental improvements in construction safety.

[0003] Therefore, to address the above shortcomings, it is necessary to provide a fire early warning system for the main tower of a cable-stayed bridge and its operating method. Summary of the Invention

[0004] To address the issue of efficient fire prevention during the construction of ultra-high main towers, the first objective of this invention is to provide a fire early warning system for cable-stayed bridge main towers.

[0005] The second objective of this invention is to provide a method for operating a fire early warning system for the main tower of a cable-stayed bridge.

[0006] The first objective of this invention is achieved as follows: A fire alarm system for the main tower of a cable-stayed bridge includes a main water tank, an auxiliary water tank, water bags, sprinklers, and water guns. The frame is installed on the outer wall of the top floor of the main tower. The main water tank is installed inside the frame, with its top extending upwards from the middle of the top plate of the frame. The auxiliary water tank is hung on the adjacent outer wall of the main tower below the climbing frame. Several water bags are placed on the frame around the main water tank. Several sprinklers are fixed at intervals to the top of the frame. One end of several water guns is connected to the water bags via a water pump, and the other end of the water guns is tied to the frame. A set of cameras is deployed every 15-20 meters on the main tower. Each set includes two visible light cameras and an infrared thermal imaging camera. Temperature, humidity, wind speed, and dust concentration sensors are deployed simultaneously.

[0007] As a further explanation of the present invention, preferably, the main water tank has a flat cylindrical structure, and a supplementary water pipe is fixedly connected between the main water tank and the auxiliary water tank to supply water to or pump water from the main water tank.

[0008] As a further explanation of the present invention, preferably, the auxiliary water tank has a cubic structure, and a set of auxiliary water tanks is hung on the main tower every 30m of pouring. The auxiliary water tanks are installed at the original wall-mounted brackets, and water supply pipes are fixedly connected between adjacent auxiliary water tanks. The water supply pipes are galvanized anti-corrosion steel pipes.

[0009] As a further explanation of the present invention, preferably, an angle steel is fixedly connected to the main tower between adjacent auxiliary water tanks, and the angle steel clamps the water supply pipe.

[0010] As a further explanation of the present invention, preferably, a relay water pump is connected to both the water supply pipe and the water replenishment pipe, and the relay water pump is fixedly connected to the auxiliary water tank.

[0011] As a further explanation of the present invention, preferably, temperature, smoke and gas sensors are evenly distributed on the climbing frame and the frame body, and float-type level gauges are installed in both the main water tank and the auxiliary water tank. The sensors and level gauges are electrically connected to the controller installed on the main tower, and the controller is electrically connected to the pump body to automatically control the storage and flow direction of water.

[0012] As a further illustration of the invention, preferably, a wind turbine and a lithium iron phosphate battery pack are mounted on the frame for additional energy storage.

[0013] The second objective of this invention is achieved as follows: A method for operating a fire early warning system for the main tower of a cable-stayed bridge includes the following steps: Ⅰ. Install one set of auxiliary water tanks for every 30m of main tower pouring. The auxiliary water tank at the top is connected to the main water tank through a water supply pipe. II. Before the climbing scaffold and frame body are raised by the hydraulic system, the main water tank is emptied. After being raised to the designated position, the scaffold body is positioned, and then water is supplied to the main water tank through the relay water pump. Ⅲ. When an open flame appears on the working floor or the temperature exceeds 68°C, the liquid in the glass bulb inside the sprinkler head expands and bursts. At this time, the water in the main water tank is sprayed into the frame through the sprinkler head by the pressure stabilizing pump to extinguish the fire and cool it down. IV. If the fire is small, the staff should first turn off the power, then remove the handheld water gun and open the upper valve of the water gun to guide the fire water in the water bag to the fire point for fire extinguishing. The main water tank will continue to supply water to the water bag.

[0014] As a further explanation of the present invention, preferably, a sedimentation tank is excavated in the open space around the bottom of the main tower, river water is introduced into the sedimentation tank and a submersible pump is placed and connected to the water supply pipe to supply water to the auxiliary water tank.

[0015] As a further explanation of the present invention, preferably, when there is no fire, a small amount of water is added to the auxiliary water tank at the top layer, so as to accommodate the water flowing out of the main water tank when the climbing frame and frame body are lifted.

[0016] The above-described technical solution of the present invention has the following advantages: The fire early warning system for the main tower of a cable-stayed bridge designed in this invention has the following advantages compared with traditional fire protection systems: 1. It reduces manual inspection costs by 40% and significantly lowers the risk of fire accidents. Furthermore, the equipment cost of approximately 1 million yuan (including water tanks, pumps, and pipes) effectively improves safety standards for high-altitude operations, provides replicable technical solutions for similar projects, and promotes the upgrading of fire protection technology in bridge construction. 2. Simultaneously, the cause of the fire was analyzed, and combined with the ignition point confirmed manually after the fire was extinguished, the analysis accuracy rate was ≥98.7%, providing clear warnings for subsequent construction, ensuring that the above problems do not occur again in subsequent construction, further ensuring construction safety, and solving the problem of how to effectively prevent fires during the construction of the ultra-high main tower. Attached Figure Description

[0017] Figure 1 This is an assembly rendering of the present invention; Figure 2 This is a test diagram of the present invention; Figure 3 This is a diagram of the nozzle mounting structure of the present invention; In the diagram: 1. Main water tank; 2. Auxiliary water tank; 21. Water supply pipe; 22. Angle steel; 23. Intermediate water pump; 24. Supplementary water pipe; 3. Water bag; 4. Sprinkler head; 5. Water gun; 6. Climbing frame; 7. Frame body; 8. Main tower; 81. Track. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] A fire early warning system for the main tower of a cable-stayed bridge, combined with Figure 1 , Figure 3The system includes a main water tank 1, an auxiliary water tank 2, water bags 3, nozzles 4, and water guns 5. The frame 7 is installed on the outer wall of the top floor of the main tower 8. The main water tank 1 is installed inside the frame 7, and the top of the main water tank 1 extends upwards to the middle of the top plate of the frame 7. The auxiliary water tank 2 is hung on the adjacent outer wall of the main tower 8 below the climbing frame 6. Several water bags 3 are placed on the frame 7 around the main water tank 1. Several nozzles 4 are fixed at intervals to the top of the frame 7. One end of several water guns 5 is connected to the water bags 3 through a water pump, and the other end of the water guns 5 is tied to the frame 7.

[0020] Combination Figure 1 , Figure 2 The main water tank 1 is a flat cylindrical structure with a diameter of 1200mm and a height of 500mm, and an effective volume of 0.5m³. 3 The main water tank 1 is made of Q235B carbon steel and coated with epoxy zinc-rich primer. It is installed at the highest point on the outer side of the steel structure platform at the top of the frame 7. A supplementary water pipe 24 is fixedly connected between the main water tank 1 and the auxiliary water tank 2 to supply or pump water to the main water tank 1. The auxiliary water tank 2 is a cubic structure made of the same material as the main water tank. One set is installed every 30m of construction height (e.g., 5 water tanks are set at elevations of +30m, +60m, +90m, +120m, and +150m for the G32# main tower). It is fixed to the original wall-mounted bracket position of the main tower 8 using U-bolts through the pre-reserved M42 climbing cone holes. Adjacent auxiliary water tanks 2 are connected by a water supply pipe 21 made of DN80 galvanized anti-corrosion steel pipe to form a vertical water supply trunk line. The outer sides of the supplementary water pipe 24 and the water supply pipe 21 are clamped and fixed with L63×6 angle steel 22 at intervals ≤3m, and the connection is sealed with grooved clamps. Both the water supply pipe 21 and the water replenishment pipe 24 are connected to a relay water pump 23, which is fixedly connected to the auxiliary water tank 2.

[0021] Temperature, smoke, and gas sensors are evenly distributed on the climbing frame 6 and frame 7. Float-type level gauges are installed in both the main water tank 1 and the auxiliary water tank 2. The sensors and level gauges are electrically connected to the controller installed on the main tower 8. The controller is electrically connected to the pump body to automatically control the storage and flow of water.

[0022] Combination Figure 1 , Figure 3 The water bags 3 are made of 50L lithium iron phosphate battery-grade waterproof coated cloth. Four sets are arranged on each frame 7, surrounding the main water tank 1, and connected to the main water tank 1 via quick connectors. A one-way valve is installed at the end of the branch pipe to prevent backflow. Four sets of closed-type sprinklers 4, model ZSTZ-68, are rectangularly distributed on the inner side of the top of the frame 7, with a spacing of 3m on the long side and 2.5m on the short side, and an installation height of 1.8m from the working surface (adjustable ±150mm). The sprinklers 4 are connected to the main water tank 1 via DN32 galvanized steel pipes, and a pressure switch is installed inside the pipes.

[0023] An additional 10kW horizontal-axis wind turbine can be installed on frame 7, paired with monocrystalline silicon photovoltaic panels. The energy is stored in a 50kWh lithium iron phosphate battery pack, providing emergency power for relay pump 23, sensors, and controllers. The wind turbine and photovoltaic panels work together to prioritize power for sensors and controllers, with surplus energy stored in the lithium battery pack. When photovoltaic power fails at night, the wind turbine provides power independently, ensuring 24-hour system operation. The battery management system (BMS) monitors voltage and temperature in real time, with an overcharge protection threshold of 4.2V and an over-discharge protection threshold of 2.75V, extending battery life. In the absence of fire, relay pump 23 operates for 5 minutes every 2 hours for pipeline inspection, with a power consumption ≤10kW·h / day; sensors enter low-power mode.

[0024] For fire detection, a set of visible light cameras can be deployed every 15-20 meters along the main tower 8, with each set containing two visible light cameras and an infrared thermal imaging camera. The visible light cameras should have a resolution ≥4K (3840×2160), a frame rate ≥30fps, a lens focal length of 8-32mm, an IP67 protection rating, support low-light shooting, be resistant to electromagnetic interference, and be able to operate in environments ranging from -40℃ to 70℃. The infrared thermal imaging cameras should have a detection wavelength of 8-14μm, a pixel count ≥640×512, a thermal sensitivity ≤50mK, a temperature measurement range of -20℃ to 600℃, an error ≤±2%, support automatic marking of high-temperature points, and be able to penetrate smoke and dust. A panoramic camera should be added to the top, middle, and bottom working platforms of the main tower 8; close-up cameras with zoom capabilities should be added to the hot work area and the flammable material storage area.

[0025] Simultaneously deployed sensors for temperature, humidity, wind speed, and dust concentration are used to fuse and analyze data and image data, optimizing image recognition algorithms (e.g., image enhancement in dusty weather) and assessing fire spread speed (e.g., upgrading warning levels in high winds). Each camera integrates a GPS / BeiDou positioning module to obtain precise coordinates, providing fundamental data for fire location.

[0026] Due to the complex high-altitude working environment of the main tower 8, wireless links, such as 4G or 5G, are preferred for data transmission. Armored optical fibers can also be laid along the tower body as a backup channel, directly connecting to the ground monitoring center with a transmission rate ≥10Gbps, strong anti-interference capability, and ensuring no data loss under extreme weather conditions. The data center uses a fusion model of CNN (Convolutional Neural Network) and LSTM (Long Short-Term Memory Network) to collect no less than 100,000 high-definition images of the concrete tower and steel bridge main tower during foundation construction, tower column pouring / assembly, beam construction, and auxiliary structure installation. Key features such as rebar density, formwork shape, and steel structure connection methods are labeled to construct the training dataset. CNN extracts image features such as scaffolding status, rebar arrangement, formwork installation, and concrete pouring marks, while LSTM captures the temporal changes during construction.

[0027] A method for operating a fire early warning system for the main tower of a cable-stayed bridge includes the following steps: I. Excavate a sedimentation tank in the open space around the bottom of the main tower 8. Fill the sedimentation tank with river water and place a submersible pump connected to the water supply pipe 21 to supply water to the auxiliary water tank 2. Install one set of auxiliary water tank 2 for every 30m of main tower 8 poured. The auxiliary water tank 2 at the top is connected to the main water tank 1 through the water supply pipe 24. II. In the absence of fire, a small amount of water is added to the auxiliary water tank 2 at the top floor. Before the climbing frame 6 and frame 7 are raised by the hydraulic system, the main water tank 1 is emptied. After being raised to the designated position, the frame is positioned and then water is supplied to the main water tank 1 through the relay water pump 23. The initial water pressure of the main water tank 1 is 0.5MPa. The pressure is maintained by the pressure stabilizing pump to ensure that the working pressure of the sprinkler head is ≥0.4MPa. III. When at least two adjacent cameras simultaneously detect a fire hazard, the working floor temperature is ≥68℃ and YOLOv5 detects sparks / smoke, or the pressure switch detects a pipeline pressure drop ≥0.2MPa, the system automatically starts sprinkler head 4. The glass bulb sprinkler head response time is ≤2s, and the single sprinkler head coverage area is 10m². 2 The entire frame can be sprayed within 30 seconds; When the water level in the main water tank 1 is below 30%, the controller starts the relay water pump 23 in the lower auxiliary water tank 2 according to priority, and adjusts the number of pumps in operation in real time through the pressure sensor to ensure the water supply pressure is 1.2MPa; the pipeline flow velocity is controlled to be ≤2.5m / s to avoid water hammer effect. IV. If the fire is small, the staff should first turn off the power, then remove the handheld water gun and open the upper valve of the water gun to guide the fire water in the water bag to the fire point for fire extinguishing. The main water tank will continue to supply water to the water bag.

[0028] If the main power supply fails, the lithium battery pack will automatically switch power (switching time ≤200ms) to maintain the relay water pump running for 30 minutes; at the same time, the water stored in the bottom auxiliary water tank 2 will be activated. Meanwhile, the water bag 3 will be connected to the branch pipe via a quick connector and can be put into use within 30 seconds.

[0029] Anti-slip steel planks are installed in the passage of frame 7, with a surface texture depth of 3mm and a 1.2m high guardrail installed on the edge. Emergency lighting will automatically turn on in case of fire, with an illuminance of ≥10lx to guide evacuation routes.

[0030] In summary, this invention solves the problem of insufficient water pressure at high altitudes by designing a 5-stage water tank system to form a vertical water supply. Compared with traditional single-tank systems, it improves water supply reliability by 30% and reduces coverage blind spots by 50%. Simultaneously, fire detection utilizes a combination of YOLOv5, decision tree algorithms, and high-temperature area detection in infrared images. By extracting the color features of flames, the dynamic features of flashing frequency, and the morphological features of irregular edges, it eliminates interference from welding sparks, sunlight reflection, etc., achieving a detection accuracy of ≥98.7% and a false alarm rate of <0.5%, enabling accurate early fire warnings. Powered by a combination of wind power, photovoltaic, and lithium batteries, it provides ≥2 hours of continuous operation after power outages, reducing dependence on the construction power grid and meeting green construction standards. Furthermore, the auxiliary water tank 2 is installed using wall-mounted brackets, avoiding additional embedded parts, improving installation efficiency by 40%, and achieving 100% compatibility with climbing formwork systems.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fire warning system for a main tower of a cable-stayed bridge, characterized in that: The system comprises a main water tank, a secondary water tank, a water bag, a spray head and a water gun, the frame body is installed on the outer side wall of the top layer of the main tower, the main water tank is installed in the frame body and the top end of the main water tank extends to the middle of the top plate of the frame body, the secondary water tank is hung on the adjacent outer side wall of the main tower below the climbing frame, several water bags are placed on the frame body around the main water tank, several spray heads are fixed and connected at intervals on the top of the frame body, one end of several water guns is connected with the water bag through a water pump, and the other end of the water gun is bound to the frame body; every 15-20 meters of the tower body of the main tower is arranged with a group of cameras, each group contains two visible light cameras and an infrared thermal imaging camera, and temperature, humidity, wind speed and dust concentration sensors are arranged synchronously.

2. The cable-stayed bridge main tower fire warning system according to claim 1, characterized in that: The main water tank is in a flat cylindrical structure, and a supplementary water pipe is fixed and connected between the main water tank and the secondary water tank to supply water to the main water tank or pump water.

3. The cable-stayed bridge main tower fire warning system according to claim 2, characterized in that: The secondary water tank is in a cubic structure, and a group of secondary water tanks are hung on the main tower every 30m of pouring, the secondary water tank is installed at the position of the original wall hanging seat, and a water supply pipe is fixed and connected between adjacent secondary water tanks, the water supply pipe is a galvanized anti-corrosion steel pipe.

4. The cable-stayed bridge main tower fire warning system according to claim 3, characterized in that: An angle steel is fixed and connected on the main tower between adjacent secondary water tanks, and the angle steel clamps the water supply pipe.

5. The cable-stayed bridge main tower fire prevention early warning system according to claim 4, characterized in that: A relay water pump is connected to the water supply pipe and the supplementary water pipe, and the relay water pump is fixed and connected to the secondary water tank.

6. The cable-stayed bridge main tower fire warning system according to claim 5, characterized in that: Temperature, smoke and gas sensors are arranged on the climbing frame and the frame body, and a float ball type liquid level meter is arranged in the main water tank and the secondary water tank, the sensors and the liquid level meter are electrically connected with a controller installed on the main tower, and the controller is electrically connected with the pump body to automatically control the storage and flow direction of water.

7. The cable-stayed bridge main tower fire warning system according to claim 6, characterized in that: A wind driven generator and a lithium iron phosphate battery pack are arranged on the frame body to store additional energy.

8. The working method of the fire warning system for the main tower of a cable-stayed bridge according to any one of claims 1-7, characterized in that: The system comprises the following steps: Ⅰ. A group of secondary water tanks are installed on the main tower every 30m of pouring, and the secondary water tank on the top layer is connected with the main water tank through a supplementary water pipe; Ⅱ. The main water tank is emptied before the climbing frame and the frame body are climbed by the hydraulic system, and the main water tank is positioned after being climbed to the specified position, and then the main water tank is supplied with water by the relay water pump; Ⅲ. When there is an open fire or the temperature is higher than 68℃ on the working layer, the glass bubble liquid in the spray head expands and breaks, at this time, the water in the main water tank is sprayed into the frame body through the spray head by the pressure stabilizing pump to extinguish the fire and reduce the temperature; Ⅳ. If the fire is small, the power is turned off first, then the handheld water gun is taken down, the upper valve of the water gun is opened, and the fire-fighting water in the water bag is guided to the fire point to extinguish the fire, and the main water tank continues to supply water to the water bag.

9. The working method of the fire warning system for the main tower of a cable-stayed bridge according to claim 8, characterized in that: A sedimentation tank is excavated in the surrounding open space at the bottom of the main tower, river water is introduced into the sedimentation tank, and a submersible pump is placed in the sedimentation tank and connected with the water supply pipe to supply water to the secondary water tank.

10. The working method of the fire warning system for the main tower of a cable-stayed bridge according to claim 9, characterized in that: When there is no fire, a small amount of water is injected into the secondary water tank on the top layer, and the water flowing out of the main water tank is contained when the climbing frame and the frame body are jacked up.

Images