Vibration sensor monitoring system and monitoring method in fire hazard

Abstract

The invention discloses a vibration sensor monitoring system and monitoring method in a fire, and belongs to the field of building structure fire safety monitoring, the system comprises a vibration monitoring mechanism, a signal cable and a data acquisition module, the vibration monitoring mechanism is arranged on the surface of a building structure component, and one end of the signal cable is connected with the vibration monitoring mechanism; the vibration monitoring mechanism comprises a sensor body, a fireproof protection shell and a magnetic base, the sensor body is arranged in the fireproof protection shell, the magnetic base is arranged at the bottom of the fireproof protection shell, and the fireproof protection shell comprises an outer metal shell, a middle flexible fireproof material and an inner aluminum foil heat insulation layer; and an expansion type fireproof sealing material is filled in the box body. According to the invention, the dynamic characteristic parameters of the building structure are obtained through the monitoring system to calculate the damage condition of the structure, a quantitative basis is provided for judging the collapse of the building structure in a fire, sensors can be arranged in a room far away from a fire, and the problems of component deformation and difficult on-site arrangement of temperature monitoring sensors are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building structure fire safety monitoring, more particularly to a vibration sensor monitoring system and method under fire. BACKGROUND

[0002] When a fire occurs, the building structure may collapse due to high temperature, which can easily cause casualties of trapped personnel and fire rescue personnel. Deformation monitoring of structural members under fire is one of the most widely researched technical means in the field of structure fire collapse risk perception and real-time early warning. Deformation is the most intuitive physical quantity reflecting the damage of structural members under fire. In the national standard "Building Component Fire Resistance Test Methods Part 1: General Requirements" (GB / T 9978.1), the component fire resistance limit is determined by the component deformation and deformation rate.

[0003] Temperature monitoring of structural members is also a widely researched technical means. High temperature is a physical quantity that directly leads to damage of structural members under fire. In the national standard "Steel Structure Fire Retardant Coating" (GB 14907-2018), the method for determining the fire resistance of steel structure fire retardant coating by component average temperature is included.

[0004] The above-mentioned deformation or temperature monitoring of structural members still faces many difficulties in practical application. For example, the deformation-based early warning method is difficult to determine due to the multiple collapse modes of the structure. The temperature-based early warning method cannot consider the changes of the load level of the structure during the fire extinguishing process and the influence of internal force redistribution of the statically indeterminate structure. The more prominent problem is that the above two methods need to be measured in the room where the fire is burning, which is difficult to arrange on site, especially when the fire occurs inside the building. SUMMARY

[0005] Therefore, the present application provides a vibration sensor monitoring system and method under fire. The present application obtains the structural dynamic characteristic parameters through the monitoring system to calculate the structural damage, which can provide quantifiable basis for the collapse determination of building structures under fire. The monitoring method can arrange sensors away from the burning room, avoiding the problem of on-site arrangement of deformation and temperature monitoring sensors.

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

[0007] A vibration sensor monitoring system under fire conditions includes a vibration monitoring mechanism, a signal cable, and a data acquisition module. The vibration monitoring mechanism is installed on the surface of a building structural component. One end of the signal cable is connected to the vibration monitoring mechanism, and the other end is connected to the data acquisition module. The vibration monitoring mechanism includes a sensor body, a fireproof protective shell, and a magnetic base. The sensor body is installed inside the fireproof protective shell, and the magnetic base is installed at the bottom of the fireproof protective shell. The fireproof protective shell has a three-layer structure, including an outer metal shell, a middle flexible fireproof material, and an inner aluminum foil insulation layer. The interior of the fireproof protective shell is filled with an intumescent fireproof sealing material. A signal cable outlet is provided on one side of the fireproof protective shell, and the outlet is sealed with a high-temperature resistant sealing sleeve made of silicone rubber.

[0008] Furthermore, the sensor body is a piezoelectric accelerometer or a microelectronic accelerometer, the sensor body has a range of 0.1-500Hz, an upper limit of operating temperature of not less than 80℃, and a protection level of IP65 or above.

[0009] Furthermore, the intermediate flexible fireproof material is selected from aluminum silicate fiber felt or aerogel felt, with a thickness of 10-30mm.

[0010] Furthermore, the thickness of the inner aluminum foil insulation layer is 0.2-0.5 mm.

[0011] Furthermore, the intumescent fireproof sealing material has a thermal expansion ratio of ≥20 times.

[0012] Furthermore, it also includes an adsorption base, which is made of steel plate and has through holes at its four corners.

[0013] Furthermore, the signal cable is a high-temperature shielded cable with a temperature resistance of ≥200℃.

[0014] A vibration sensor monitoring method under fire conditions includes the following steps:

[0015] S01. Surface treatment of building structural components: The surface of the components is treated to the point that the magnetic seat of the vibration monitoring mechanism can be directly adsorbed onto the surface of the components;

[0016] S02. Install vibration monitoring mechanism: The vibration monitoring mechanism shall be arranged at a distance of ≥1m from door and window openings to avoid direct impact from overflowing flames. The sensor shall be attached to the surface of the building structure component by magnetic base and tightened, and the signal cable shall be connected to the data acquisition module. The number of vibration monitoring mechanisms shall not be less than 3.

[0017] S03. Power-on debugging: Power on the data acquisition module and connect it to the vibration monitoring mechanism of the building structure under fire conditions to ensure that the vibration signal acquisition is normal and there is no abnormal noise.

[0018] Furthermore, different treatment methods are used for components made of different materials:

[0019] For steel structures without fire protection, remove surface rust and oil stains;

[0020] For steel structures with fire protection, the fire-retardant coating at the location where the vibration monitoring equipment is to be installed will be removed;

[0021] For concrete and wood structures, fix the adsorption base at the location where the vibration monitoring device is installed, and ensure that the adsorption base is not loose.

[0022] Furthermore, different installation locations should be selected for different building structures:

[0023] For frame structures, key components are selected on the outer side of the ground floor and around the room closest to the fire, and vibration monitoring mechanisms are arranged in the columns and beams of the key components respectively.

[0024] For masonry structures and shear wall structures, vibration monitoring devices are installed at the center of the ground floor wall closest to the room on fire and the center of the surrounding walls.

[0025] For factory buildings and tall, spacious structures, vibration monitoring devices should be installed at a convenient height at the bottom of the column closest to the fire location.

[0026] The beneficial effects of this invention are as follows:

[0027] 1. Strong adaptability to high temperature environment: The present invention, through the combination design of three-layer fireproof protective shell and expansion-type sealing material, raises the upper limit of sensor operating temperature to 500℃, which can withstand high temperature and smoke corrosion in fire environment, ensure monitoring continuity and extend the monitoring window period.

[0028] 2. Easy installation and high adaptability: The magnetic base of this invention, combined with the optional adsorption base, can be quickly adapted to different types of building components such as steel structures, concrete, and wood structures, providing differentiated installation and surface treatment solutions. It has strong engineering applicability, meets diverse on-site installation needs, and improves deployment efficiency.

[0029] 3. High monitoring reliability: The sensor body parameters of this invention are adapted to the structural vibration range under fire conditions. It is equipped with high-temperature resistant cables and a sealed design. Combined with standardized installation and commissioning procedures, it ensures stable vibration signal acquisition (frequency 0.1-500Hz) and no interference.

[0030] 4. Scientific and reasonable layout: The sensor body can be placed away from the room on fire, avoiding the impact of high temperature and direct flame impact on the monitoring equipment, significantly reducing the difficulty and risk of on-site installation. It is especially suitable for fire scenarios inside buildings, and targeted layout schemes are formulated for different structural types, specifying the quantity and location requirements. The selectable installation height and location facilitate on-site operation, and can accurately capture key vibration information of building structures under fire. Through the deployment of multiple sensors and data acquisition, real-time monitoring and damage prediction of structural dynamic characteristics can be achieved, providing scientific and quantifiable technical support for the assessment of the collapse risk of building structures in fire environments, which helps to improve the safety and effectiveness of fire rescue. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the connection of the vibration sensor monitoring system under fire according to the present invention;

[0032] Figure 2 This is a schematic diagram of the internal structure of the vibration monitoring mechanism of the present invention;

[0033] Figure 3 This is a schematic diagram showing the vibration monitoring mechanism and the adsorption base of the present invention in action;

[0034] Figure 4 This is a schematic diagram of the vibration monitoring mechanism and adsorption base of the present invention installed on a planar component;

[0035] Figure 5 This is a schematic diagram of the vibration monitoring mechanism and adsorption base of the present invention installed on the cylindrical component;

[0036] Figure 6 This is a schematic diagram showing the arrangement of the vibration monitoring mechanism of the present invention in a building structure.

[0037] In the diagram: 1. Vibration monitoring mechanism; 2. Sensor body; 3. Fireproof protective shell; 4. Magnetic base; 5. Metal shell; 6. Flexible fireproof material; 7. Aluminum foil insulation layer; 8. Intumescent fireproof sealing material; 9. Signal cable outlet; 10. High-temperature resistant sealing sleeve; 11. Adsorption base; 12. Through hole; 13. Data acquisition module; 14. Signal cable; 15. Fired room. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0039] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "horizontal," "inner," "outer," and "one side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0040] Example 1

[0041] like Figures 1-6 As shown, this invention discloses a vibration sensor monitoring system under fire conditions. Since the natural vibration period, frequency, and other dynamic characteristic parameters of a structure are inherent features of a specific state, changes in these parameters, to a certain extent, represent whether the structure is functioning normally and even reflect the damage and failure process. The core principle of this invention is based on the fact that damage to a structure under fire will cause changes in its mass, stiffness, damping, etc., to varying degrees, further leading to changes in its natural frequency, mode shape, and modal parameters. This invention uses a monitoring system to obtain the structural dynamic characteristic parameters to estimate the structural damage, providing a quantifiable basis for determining the collapse of building structures under fire. This invention allows sensors to be deployed far from the room where the fire is located, avoiding the difficulties in on-site deployment of sensors for component deformation and temperature monitoring.

[0042] The present invention includes a vibration monitoring mechanism 1, a signal cable 14 and a data acquisition module 13. The vibration monitoring mechanism 1 is installed on the surface of the building structure component. One end of the signal cable 14 is connected to the vibration monitoring mechanism 1 and the other end is connected to the data acquisition module 13. The vibration monitoring mechanism 1 includes a sensor body 2, a fireproof protective shell 3 and a magnetic base 4.

[0043] The sensor body 2 can be a piezoelectric accelerometer or a microelectronic accelerometer, with a measurement range adapted to the vibration range of building structures under fire (0.1-500Hz), an upper limit of operating temperature of not less than 80℃, and waterproof and dustproof functions (protection level IP65 and above).

[0044] The fireproof protective shell 3 adopts a three-layer structure. The outer layer is a metal shell 5 that is firmly connected to the magnetic base 4. The middle layer is a flexible fireproof material 6 (thickness 10-30mm). The inner layer is an aluminum foil heat insulation layer 7 (thickness 0.2-0.5mm). The inner side of the shell is filled with an intumescent fireproof sealing material 8 (heat expansion ratio ≥20 times). Preferably, the flexible fireproof material 6 can be aluminum silicate fiber felt or aerogel felt. With the protection of the fireproof protective shell, the upper limit of the working temperature of the building structure vibration monitoring mechanism 1 under fire is increased to 500℃.

[0045] The fireproof protective shell 3 has a signal cable outlet 9 with a diameter of 5-8mm on one side. The outlet is sealed with a high-temperature resistant sealing sleeve 10 (made of silicone rubber, with an operating temperature of -60℃ to 250℃) to prevent high-temperature smoke from entering.

[0046] Preferably, for building structural components other than steel structures, the magnetic base 4 can be matched with an adsorption base 11. The adsorption base 11 is made of steel plate with a thickness of 5-8mm. The size of the adsorption base 11 is not smaller than that of the magnetic base 4. The adsorption base 11 has through holes 12 at the four corners, which facilitates the quick fixing of the adsorption base 11 to the surface of the building structural component on site using an electric drill or other means.

[0047] Preferably, the adsorption base 11 can be designed as a plane or a cylinder to fit the component being tested, depending on the shape of the building structural component.

[0048] In a preferred embodiment of the present invention, the signal cable 14 is a high-temperature shielded cable (temperature resistance ≥200℃), and the cable passes through the high-temperature sealing sleeve 10 at the signal cable outlet 9 of the protective shell and is connected to the data acquisition module 13.

[0049] Example 2

[0050] This embodiment also discloses a monitoring method based on the monitoring system in Embodiment 1, including the following steps:

[0051] S01. Surface treatment of building structural components: The surface of the components shall be treated to a state in which the magnetic base 4 of the vibration monitoring mechanism 1 can be directly adsorbed onto the surface of the components. Different treatment methods shall be adopted for components of different materials. For steel structures without fire protection, obvious rust and oil stains shall be removed; for steel structures with fire protection, the fireproof coating at the location where the vibration monitoring mechanism 1 is to be installed shall be removed; for concrete structures, wood structures, etc., the adsorption base 11 shall be fixed at the location where the vibration monitoring mechanism 1 is to be installed, and it shall be ensured that the adsorption base 11 is not loose.

[0052] S02. Installation of Vibration Monitoring Mechanism: The vibration monitoring mechanism 1 is attached to the surface of the building structural component using the magnetic base 4 and tightened. The signal cable 14 is connected to the data acquisition module 13. The number of vibration monitoring mechanisms 1 should be no less than three. For general frame structures, key components can be selected on the outer side of the building's ground floor closest to 15 and around it. Vibration monitoring mechanisms 1 are then placed in the columns (at 1 / 2 of the column height) and beams (at 1 / 2 of the beam length) of these key components. For masonry structures, shear wall structures, etc., vibration monitoring mechanisms 1 can be placed at the center of the ground floor wall closest to the fire room 15 and several surrounding walls. For tall, open spaces such as factory buildings, vibration monitoring mechanisms 1 can be placed at a convenient installation height (1.5m-2m) at the bottom of the column closest to the fire location. The placement of the vibration monitoring mechanism 1 should be at least 1m away from door and window openings to avoid direct impact from potentially overflowing flames, significantly reducing the thermal protection requirements for the sensor body 2.

[0053] S03. Power-on debugging: Power on the data acquisition module 13 and connect it to the vibration monitoring mechanism 1 for the building structure under fire to ensure that the vibration signal acquisition is normal and there is no abnormal noise.

[0054] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A vibration sensor monitoring system under fire conditions, characterized in that, The system includes a vibration monitoring mechanism, a signal cable, and a data acquisition module. The vibration monitoring mechanism is installed on the surface of the building structural component. One end of the signal cable is connected to the vibration monitoring mechanism, and the other end is connected to the data acquisition module. The vibration monitoring mechanism includes a sensor body, a fireproof protective shell, and a magnetic base. The sensor body is installed inside the fireproof protective shell, and the magnetic base is installed at the bottom of the fireproof protective shell. The fireproof protective shell has a three-layer structure, including an outer metal shell, a middle flexible fireproof material, and an inner aluminum foil heat insulation layer. The interior of the fireproof protective shell is filled with an intumescent fireproof sealing material. A signal cable outlet is provided on one side of the fireproof protective shell, and the outlet is sealed with a high-temperature resistant sealing sleeve made of silicone rubber.

2. The vibration sensor monitoring system under fire conditions according to claim 1, characterized in that, The sensor body is a piezoelectric accelerometer or a microelectronic accelerometer. The sensor body has a range of 0.1-500Hz, an upper limit of operating temperature of not less than 80℃, and a protection level of IP65 or above.

3. A vibration sensor monitoring system under fire conditions according to claim 1, characterized in that, The intermediate flexible fireproof material is made of aluminum silicate fiber felt or aerogel felt, with a thickness of 10-30mm.

4. A vibration sensor monitoring system under fire conditions according to claim 1, characterized in that, The thickness of the inner aluminum foil insulation layer is 0.2-0.5 mm.

5. A vibration sensor monitoring system under fire conditions according to claim 1, characterized in that, The intumescent fireproof sealing material expands by ≥20 times when heated.

6. A vibration sensor monitoring system under fire conditions according to claim 1, characterized in that, It also includes an adsorption base, which is made of steel plate and has through holes at its four corners.

7. A vibration sensor monitoring system under fire conditions according to claim 1, characterized in that, The signal cable is a high-temperature shielded cable with a temperature resistance of ≥200℃.

8. A monitoring method for a vibration sensor monitoring system under fire conditions according to any one of claims 1-7, characterized in that, Includes the following steps: S01. Surface treatment of building structural components: The surface of the components is treated to the point that the magnetic seat of the vibration monitoring mechanism can be directly adsorbed onto the surface of the components; S02. Install vibration monitoring mechanism: The vibration monitoring mechanism shall be arranged at a distance of ≥1m from door and window openings to avoid direct impact from overflowing flames. The sensor shall be attached to the surface of the building structure component by magnetic base and tightened, and the signal cable shall be connected to the data acquisition module. The number of vibration monitoring mechanisms shall not be less than 3. S03. Power-on debugging: Power on the data acquisition module and connect it to the vibration monitoring mechanism of the building structure under fire conditions to ensure that the vibration signal acquisition is normal and there is no abnormal noise.

9. The monitoring method of a vibration sensor monitoring system under fire according to claim 8, characterized in that, In step S01, different processing methods are used for components made of different materials: For steel structures without fire protection, remove surface rust and oil stains; For steel structures with fire protection, the fire-retardant coating at the location where the vibration monitoring equipment is to be installed will be removed; For concrete and wood structures, fix the adsorption base at the location where the vibration monitoring device is installed, and ensure that the adsorption base is not loose.

10. The monitoring method of a vibration sensor monitoring system under fire according to claim 8, characterized in that, In step S02, different installation locations are selected for different building structures: For frame structures, key components are selected on the outer side of the ground floor and around the room closest to the fire, and vibration monitoring mechanisms are arranged in the columns and beams of the key components respectively. For masonry structures and shear wall structures, vibration monitoring devices are installed at the center of the ground floor wall closest to the room on fire and the center of the surrounding walls. For factory buildings and tall, spacious structures, vibration monitoring devices should be installed at a convenient height at the bottom of the column closest to the fire location.

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