Fireproof detection and evaluation device and method for inflatable composite high-voltage cable

Abstract

The invention discloses a fireproof detection and evaluation device and method for an inflatable composite high-voltage cable, the fireproof detection and evaluation device comprises lead sealing pieces, monitoring equipment and a controller, the controller is electrically connected with the monitoring equipment, the lead sealing pieces are used for being arranged at two ends of a cable body and sealing the cable body, and the monitoring equipment is electrically connected with the controller. The monitoring device comprises an acquisition assembly and an air supply part, the air supply part is used for being communicated with the interior of the cable body and inflating the cable body, and the acquisition assembly is used for monitoring and acquiring experimental data. Specific gas (such as nitrogen, carbon dioxide and heptafluoropropane) is filled into the cable body (the cable buffer layer) through the gas supply part, and various properties are monitored and recorded by using the acquisition assembly, so that the limitation of a traditional detection method is overcome, and the fireproof performance of the cable in a fire disaster can be evaluated more comprehensively and deeply.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage cable fire protection, and in particular to a fire protection detection and evaluation device and method for an inflatable composite high-voltage cable. Background Art

[0002] With the rapid development of the power industry, high-voltage cables play a vital role in power transmission systems. However, fire protection for high-voltage cables remains a key concern within the power industry. The fire resistance of cables is directly linked to the safe and stable operation of power systems, particularly in complex and changing environments. Traditional cable fire detection methods are often limited to monitoring the external environment, making it difficult to penetrate deep into the cable, and unable to fully and accurately assess the cable's actual performance in a fire.

[0003] Chinese patent publication number CN114646724A discloses a method, system, device and method of use for evaluating the overall fire protection performance of cables. In this document, a device for evaluating the overall fire protection performance of cables is disclosed, including a controller and a standard cable channel. The standard cable channel is provided with an arc fire source device, a concentration sensor and a temperature measurement and recording device. The standard cable channel is used to place cables with a combination of passive fire protection products and active fire protection products applied; the power supply circuit of the arc fire source device is controlled by the controller, and the arc fire source device is used to ignite the cable; the concentration sensor is connected to the controller to collect the concentration of toxic gases and smoke particles; the temperature measurement and recording device is connected to the controller to measure the temperature and record the cable ignition process. This technical solution realizes the evaluation of the overall fire resistance performance of the cable, rather than being limited to the detection of the fire resistance performance of the cable itself or the fireproof material itself. The evaluation is more comprehensive and in line with reality. However, the applicant found that when using this technical solution to perform fire protection detection on composite inflatable cables, its fire resistance performance cannot be well evaluated because: this technical solution does not take into account the influence of the internal gas environment of the cable on the fire resistance performance. In particular, when dealing with inflatable composite high-voltage cables, the gas environment inside the cable (such as gas type, pressure, etc.) has an important influence on the fire resistance performance; if there is flammable or combustion-supporting gas inside the cable, or the gas pressure is insufficient, the fire protection effect may be greatly reduced. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a fire detection and evaluation device and method for inflatable composite high-voltage cables, which can comprehensively and deeply evaluate the fire protection performance of inflatable composite high-voltage cables in fire.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A fire detection and evaluation device for an inflatable composite high-voltage cable includes a lead seal, a monitoring device, and a controller. The controller is electrically connected to the monitoring device. The lead seal is used to be set at both ends of the cable body and seal the cable body. The monitoring device includes a collection component and an air supply component. The air supply component is used to communicate with the interior of the cable body and inflate the cable body. The collection component is used to monitor and collect experimental data.

[0007] As a further improvement of the above technical solution:

[0008] It also includes a communication pipe, which is used to connect the air supply component with the interior of the cable body.

[0009] The collection component further includes a flow meter, which is located on the communicating pipe.

[0010] The collection component further includes a pressure gauge, which is located on the connecting pipe.

[0011] The acquisition component further includes a signal acquisition component, which is used to detect the air pressure inside the acquisition cable body.

[0012] It also includes a combustion cabinet, the lead sealing component is located inside the combustion cabinet, and the air supply component is located outside the combustion cabinet.

[0013] The collection component also includes an oxygen detector, a heat flow tester and a thermometer located in the combustion cabinet. The oxygen detector is used to detect the oxygen content in the combustion cabinet, the heat flow tester is used to detect the heat flow near the cable body, and the thermometer is used to detect the flame temperature in the combustion cabinet.

[0014] The oxygen detector is a gun-type oxygen gas detector.

[0015] A fire detection and evaluation method for an inflatable composite high-voltage cable is performed using the aforementioned fire detection and evaluation device for an inflatable composite high-voltage cable, including evaluating a fire condition inside the cable body and / or evaluating a fire condition outside the cable body.

[0016] The step of evaluating the fire inside the cable body comprises the following steps:

[0017] A1. Seal both ends of the cable body with lead seals and install the monitoring equipment;

[0018] A2. Open the gas supply component to fill the cable body with gas, and the acquisition component records the experimental data in real time;

[0019] A3. Evaluate the fire resistance performance of the cable body based on the recorded data.

[0020] The experimental data include gas flow rate and gas flow rate.

[0021] The method of evaluating the fire situation outside the cable body comprises the following steps:

[0022] B1. Seal both ends of the cable body with lead seals and install the monitoring equipment;

[0023] B2. Open the gas supply component to fill the cable body with gas, burn the cable body with flame, and collect the experimental data in real time;

[0024] B3. Evaluate the fire resistance performance of the cable body based on the recorded data.

[0025] The experimental data include oxygen content, heat flux and flame temperature.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention provides a device and method for detecting and evaluating the fire protection of an inflatable composite high-voltage cable. The device of the present invention fills the cable body (cable buffer layer) with specific gases (such as nitrogen, carbon dioxide, and heptafluoropropane) through a gas supply component, and uses a collection component to monitor and record various experimental data. This not only overcomes the limitations of traditional detection methods, but also can more comprehensively and deeply evaluate the fire protection performance of the cable in a fire. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural diagram of the fire detection and evaluation device of Example 1.

[0029] Figure 2 This is a brief method flow chart of embodiment 3 of the present invention.

[0030] Figure 3 This is a detailed method flow chart of embodiment 3 of the present invention.

[0031] Figure 4 It is a structural diagram of a fire detection and evaluation device according to a fourth embodiment of the present invention.

[0032] Figure 5 This is a brief method flow chart of Example 5 of the present invention.

[0033] Figure 6 This is a detailed method flow chart of embodiment 5 of the present invention.

[0034] The numbers in the figure represent: 1. Cable body; 2. Lead seal; 3. Air supply component; 4. Signal acquisition component; 5. Controller; 6. Connecting pipe; 7. Flow meter; 8. Pressure gauge; 9. Oxygen detector; 10. Heat flow tester; 11. Thermometer; 12. Combustion cabinet. DETAILED DESCRIPTION

[0035] The present invention will be described in further detail below. Unless otherwise specified, the instruments and materials used in the present invention are commercially available.

[0036] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0038] In the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0039] The inflatable composite high-voltage cable of the present invention uses the space between the aluminum sheath and the insulated core as a container for storing mixed gas. By filling the cavity of the cable body's buffer layer with mixed gas, the cable itself has the ability to actively suppress and protect against fire and water seepage. From the inside out, it includes the following structures:

[0040] ① Conductor: Usually made of copper or aluminum, used to transmit electrical energy.

[0041] ②Insulation layer: Made of cross-linked polyethylene and other polymer materials to prevent leakage and breakdown of the cable.

[0042] ③ Shielding layer: composed of metal braided mesh or metal tape, used to reduce electromagnetic interference and improve the electromagnetic compatibility of the cable.

[0043] ④ Buffer layer: In the inflatable composite high-voltage cable, the space between the buffer layer and the aluminum sheath is used as a container for storing mixed gas.

[0044] ⑤Aluminum sheath: As the outer protection of the cable, it has functions such as waterproof, moisture-proof, anti-corrosion, and resistance to mechanical damage.

[0045] ⑥ Outer sheath: usually made of materials such as polyvinyl chloride to further protect the cable.

[0046] Example 1

[0047] like Figure 1 As shown, the fire detection and evaluation device for an inflatable composite high-voltage cable of this embodiment includes a lead seal 2, a monitoring device, and a controller 5. The controller 5 is electrically (wired or wirelessly) connected to the monitoring device. The lead seal 2 is used to be set at both ends of the cable body 1 and to seal the cable body 1. The monitoring device includes a collection component and an air supply component 3. The air supply component 3 is used to communicate with the interior of the cable body 1 and to inflate the cable body 1. The collection component is used to monitor and collect experimental data. The device of the present invention fills the cable body with a specific gas (such as nitrogen, carbon dioxide, or heptafluoropropane) through the air supply component and uses the collection component to monitor and record various experimental data. This not only overcomes the limitations of traditional detection methods, but also can more comprehensively and deeply evaluate the fire performance of the cable in a fire.

[0048] Example 2

[0049] The fire detection and evaluation device for an inflatable composite high-voltage cable of this embodiment includes a lead seal 2, a monitoring device and a controller 5. The controller 5 is electrically (wired or wirelessly) connected to the monitoring device. The lead seal 2 is used to be set at both ends of the cable body 1 and to seal the cable body 1. The monitoring device includes a collection component and an air supply component 3. The air supply component 3 is used to communicate with the interior of the cable body 1 and to inflate the cable body 1. The collection component is used to monitor and collect experimental data during evaluation.

[0050] In this embodiment, the acquisition assembly includes a signal acquisition component 4, which is used to detect the air pressure inside the cable body 1. Lead seals 2 are used at both ends of the cable body 1 to ensure airtightness during the experiment.

[0051] In this embodiment, the signal collecting component 4 is installed on the lead seal 2 at one end of the cable body 1 and is used to monitor the internal pressure and other gas contents of the cable.

[0052] In this embodiment, a communication pipe 6 is further included, and the communication pipe 6 is used to connect the air supply component 3 with the interior of the cable body 1.

[0053] In this embodiment, the collection component includes a flow meter 7 and a thermometer 11. In this embodiment, the flow meter is a tiny digital gas mass flow meter, and there are two of them, which are respectively installed on the connecting pipe 6 at one end of the cable body 1 and the middle part of the cable body 1 (the end is the air inlet, the middle is the air outlet, and the flow meter 7 at the air outlet is used to compare with the flow meter 7 at the air inlet to observe how many seconds of delay there is compared between the air outlet and the air inlet, and whether the flow rate is equal), and is used to measure the gas flow rate and flow. The thermometer 11 is located below the flow meter 7 in the middle part of the cable and is used to detect the flame temperature in the combustion cabinet 12.

[0054] In this embodiment, the inflation pressure of the air supply component 3 is 0.2MPa-0.4MPa.

[0055] In this embodiment, a combustion cabinet 12 is further included, wherein the lead seal 2 and the signal collecting component 4 are located inside the combustion cabinet 12, and the air supply component 3 is located outside the combustion cabinet 12. The combustion cabinet 12 is used to simulate a fire environment.

[0056] The collection component further includes a pressure gauge 8, which is located on the connecting pipe 6. In this embodiment, the pressure gauge 8 is connected between the air supply component 3 and the cable body 1 to monitor and adjust the pressure of the air inlet.

[0057] In this embodiment, the cable body 1 is a 110kV cross-linked polyethylene insulated power cable with a length of about 4 meters. The cable body 1 includes a core layer, an air-filled layer, and an insulating layer. The insulating layer is wrapped around the core layer, and the air-filled layer is located between the insulating layer and the core layer.

[0058] In this embodiment, the gas supply component 3 is a 40L nitrogen tank for supplying nitrogen to the interior of the cable. In other embodiments, the gas in the gas supply component 3 is carbon dioxide and heptafluoropropane, and the same or similar technical effects can also be achieved.

[0059] Example 3

[0060] like Figure 2 As shown, a fire detection and evaluation method for an inflatable composite high-voltage cable of the present invention evaluates the sealing and fire resistance of the inflatable composite high-voltage cable in a closed environment after being filled with specific gases (nitrogen, carbon dioxide and heptafluoropropane). The method is performed using the fire detection and evaluation device for an inflatable composite high-voltage cable of Example 2, including evaluating the fire situation inside the cable body 1, and specifically comprising the following steps:

[0061] A1. Seal both ends of the cable body 1 with lead seals 2 and install the monitoring equipment;

[0062] A2. Open the gas supply component 3 to fill the cable body 1 with gas, and collect the experimental data.

[0063] A3. Evaluate the fire resistance performance of the cable body 1 based on the recorded experimental data.

[0064] The experimental data include gas flow rate and gas flow rate.

[0065] like Figure 3 As shown, the fire detection and evaluation method for an inflatable composite high-voltage cable of this embodiment specifically includes the following steps:

[0066] (1) Cable Preparation: Select and prepare cables of specified specifications, ensuring that both ends of the cable body 1 are intact. Install lead seals 2 at both ends of the cable body 1 and place the cable body 1 in the combustion cabinet 12, ensuring that the combustion cabinet 12 is sealed.

[0067] (2) Installing the signal acquisition component 4: Install the signal acquisition component 4 on the lead seal 2 at one end of the cable body 1. The signal acquisition component 4 is connected to the external controller 5 in a wireless or wired manner.

[0068] (3) Drilling and connection: Use an electric drill to drill a hole in the middle of the other end of the cable body 1, install a small digital gas mass flow meter as the flow meter 7, use a flame-retardant snake skin tube as the connecting pipe 6, and connect the flame-retardant snake skin tube to the air supply component 3, and connect a pressure gauge 8 in the middle of the connecting pipe 6.

[0069] The caliber of the holes is between 4 mm and 20 mm, and in this embodiment is 20 mm, to ensure that all connections are well sealed to prevent gas leakage.

[0070] (4) Inflating operation: Open the air supply component 3, add nitrogen to the inside of the cable body 1, and adjust the pressure gauge 8 at the air inlet to keep the pressure at 2 or 4 atmospheres.

[0071] According to different experimental conditions, the air supply mode can be set to always supply air or not supply air after the initial pressure is released.

[0072] (5) Data recording: The signal acquisition unit 4, thermometer 11, and flowmeter 7 are used to record parameters such as pressure, temperature, gas velocity, and flow rate inside and around the cable body 1 in real time. At the same time, a micrometer is used to measure minute changes in the structure of the cable body 1 before and after inflation to assess the deformation of the cable body 1.

[0073] Data analysis: Compare the data under different experimental conditions, such as gas type (nitrogen, carbon dioxide and heptafluoropropane), outlet aperture (such as 4mm, 10mm, 20mm), air pressure of the air inlet (such as 0.2MPa, 0.4MPa), and the presence or absence of constant air supply, and analyze the impact of these factors on the fire protection performance of the cable.

[0074] During the experiment, detailed records were kept of changes in various parameters, including gas velocity and flow rate. By comparing and analyzing data from different experimental conditions, the fire resistance performance of the cable under different conditions can be determined. For example, by comparing the experimental results using nitrogen, carbon dioxide, and heptafluoropropane as the inflation gas, the impact of different gases on the cable's fire resistance can be evaluated; by comparing the experimental results of different gas outlet apertures, the effect of aperture size on the cable's internal pressure distribution and fire resistance can be understood. Gas flowing out of the cable has a certain flow rate and occupies a certain volume in the air. Generally, the faster the flow rate, the better the fire suppression effect, and the larger the volume of gas in the air, the better the fire suppression effect.

[0075] The flow rate and flow rate data under the air supply state, with an air pressure of 0.4 MPa and a time of 10 s are listed below, as shown in Table 1 and Table 2.

[0076] Table 1 Flow rate table (unit: m / s) when the air pressure is 0.4 MPa in the air supply state

[0077]

[0078] Table 2 Flow rate table (unit: L) when the air pressure is 0.4 MPa in the air supply state

[0079]

[0080] (1) As can be seen from Table 1, the three gases show a regular pattern: when the outlet aperture increases from 4 mm to 10 mm, the flow rate increases significantly; when the outlet aperture increases from 10 mm to 20 mm, the flow rate decreases, but is still higher than the flow rate when the aperture is 4 mm. This is because as the aperture increases, the resistance of the gas passing through the aperture decreases, allowing more gas to pass quickly, resulting in a significant increase in the flow rate in the initial stage. At the same time, as the aperture increases, the friction resistance in the pipe decreases, but at the same time, more turbulence may be introduced, which will offset the increase in flow rate to a certain extent. In particular, when the aperture increases from 10 mm to 20 mm, the turbulent effect may become more significant, resulting in a slight decrease in flow rate.

[0081] (2) As shown in Table 2, the flow rate continues to increase as the outlet aperture increases. According to the orifice flow formula in fluid mechanics, the flow rate is proportional to the orifice area. Therefore, as the aperture increases, the orifice area increases, resulting in an increase in flow rate.

[0082] (3) By comparing various data with or without air replenishment, different air pressures, and different apertures, the final conclusion is: in the air replenishment state, when the air pressure is 0.4MPa and the aperture is 20mm, the flow rate of heptafluoropropane is the largest and the fire extinguishing effect is the best.

[0083] This embodiment relies on the detected flow rate data to evaluate the fire protection performance. The flow rate is a key parameter for the flow of gas inside the cable, which directly affects the pressure distribution and gas renewal rate inside the cable. Through a high-precision micro-digital gas mass flowmeter, the flow rate and flow rate of the gas at the cable inlet and outlet can be accurately measured, thereby achieving the following effects: (1) Evaluate the sealing of the cable: By measuring the flow rate and flow rate, it can be determined whether the sealing devices (such as lead seals) at both ends of the cable are tight to prevent gas leakage. (2) Monitor the gas renewal rate: Understanding the flow rate of gas inside the cable helps to evaluate the diffusion and suppression effect of fire-retardant gas in cable fires.

[0084] Example 4

[0085] like Figure 4 As shown, the fire detection and evaluation device for the inflatable composite high-voltage cable of this embodiment includes, in addition to all the parts of the second embodiment, an acquisition component also includes an oxygen detector 9 and a heat flow tester 10 located in the combustion cabinet 12. The oxygen detector 9 is used to detect the oxygen content in the combustion cabinet 12, and the heat flow tester 10 is used to detect the heat flow near the cable body 1.

[0086] This embodiment is an external fire test scheme, which is intended to simulate a fire environment and evaluate the fire protection performance of the inflatable composite high-voltage cable under fire conditions.

[0087] In this embodiment, the cable body 1 is the same as that in the second embodiment, and is also a 110 kV cross-linked polyethylene insulated power cable with a length of about 4 meters.

[0088] In this embodiment, the thermometer 11 is a high-precision digital thermometer used to measure the flame temperature in the combustion cabinet 12 .

[0089] In this embodiment, the oxygen detector 9 is a probe-type oxygen gas detector, which is used to measure the oxygen content in the space of the combustion cabinet 12.

[0090] In this embodiment, the patch of the heat flow tester 10 is placed near the burning part of the cable body 1 to measure the heat flow.

[0091] The gas supply component 3 of this embodiment is the same as the gas supply component 3 of the second embodiment, and is used to supply gas to the inside of the cable when needed.

[0092] Example 5

[0093] like Figure 5 As shown, a fire detection and evaluation method for an inflatable composite high-voltage cable of the present invention is performed using a fire detection and evaluation device for an inflatable composite high-voltage cable according to the fourth embodiment, comprising evaluating the external fire condition of the cable body (1), specifically comprising the following steps:

[0094] B1. Seal both ends of the cable body 1 with lead seals 2 and install the monitoring equipment;

[0095] B2. Open the gas supply component 3 to fill the cable body 1 with gas, burn the cable body 1 with flame, and collect the experimental data;

[0096] B3. Evaluate the fire resistance performance of the cable body 1 based on the recorded experimental data.

[0097] The experimental data include oxygen content, heat flux and flame temperature.

[0098] like Figure 6 As shown, the fire detection and evaluation method for an inflatable composite high-voltage cable of this embodiment specifically includes the following steps:

[0099] (1) Cable preparation: Place the cable into the combustion cabinet 12, ensuring that both ends of the cable are exposed for easy connection to the monitoring equipment.

[0100] (2) Install monitoring equipment: Install a thermometer 11 near the flame and an oxygen detector 9 on the top of the combustion cabinet 12 to ensure accurate measurement of the flame temperature and the oxygen content in the combustion cabinet 12. Place the patch of the heat flow tester 10 near the burning part of the cable body 1 to measure the heat flow.

[0101] (3) Start the combustion equipment: Start the flame in the combustion cabinet 12 to simulate a fire environment. According to the experimental needs, adjust the flame size and distance to simulate fire scenes under different fire conditions.

[0102] (4) Data recording: Use instruments such as thermometer 11, oxygen detector 9 and heat flow tester 10 to record parameters such as flame temperature, oxygen content and heat flow in real time. At the same time, pay attention to the combustion and deformation of the cable body 1.

[0103] Data Analysis: Compare data under different experimental conditions, such as flame size, distance, and whether or not gas is added to the cable, to analyze the impact of these factors on the cable's fire resistance. By comparing data changes under different conditions, the cable's fire resistance performance can be evaluated under fire conditions.

[0104] During external fire tests, detailed records are kept of changes in parameters such as flame temperature, oxygen content, and heat flux. By comparing and analyzing data from different experimental conditions, the cable's fire performance under fire conditions can be determined. For example, by comparing experimental results with and without air supply, the impact of air supply on the cable's fire performance can be assessed. By comparing experimental results under different flame sizes and distances, the impact of fire intensity on the cable's fire performance can be understood.

[0105] The following lists the data of oxygen content directly above the cable, heat flux on the surface near the cable combustion, and flame temperature when the air pressure is 0.4 MPa, the aperture is 20 mm, and the time is 10 s, as shown in Table 3.

[0106] Table 3 Parameters of the air supply state, air pressure is 0.4MPa, aperture is 20mm

[0107]

[0108] Data Analysis:

[0109] (1) As shown in Table 3, under the air supply state, the air pressure is 0.4 MPa, and the pore diameter is 20 mm, the oxygen content of heptafluoropropane gas is the lowest, reaching 12.6%; the heat flow through the cable skin is the lowest, at 18.5 kW; the flame temperature is the lowest, at 405 ° C. The three parameters have the best fire extinguishing effect.

[0110] (2) By comparing various data with or without air supply, different air pressures, and different apertures, the final conclusion is: in the air supply state, when the air pressure is 0.4MPa, the aperture is 20mm, and the gas type is heptafluoropropane, the oxygen content around the cable is the lowest, the heat flow through the cable skin is the lowest, the flame temperature is the lowest, and the fire extinguishing effect is the best.

[0111] This example evaluates fire protection performance based on temperature, oxygen content, and heat flow data for the following reasons:

[0112] 1. Temperature

[0113] Rationale: Temperature is a key indicator for evaluating cable performance in fire. High-precision digital thermometers and probe-type oxygen gas detectors can be used to monitor flame temperature and the temperature within the combustion cabinet in real time.

[0114] Purpose: To monitor the fire source temperature: Understanding the temperature changes of the fire source helps to simulate real fire scenes and provide accurate environmental conditions for the evaluation of cable fire protection performance.

[0115] 2. Oxygen content

[0116] Basis: Oxygen is one of the necessary conditions for combustion. The oxygen content in the combustion cabinet space can be monitored in real time through a probe-type oxygen gas detector.

[0117] Purpose:

[0118] (1) Evaluating the oxygen suppression effect of fire retardant gases: Fire retardant gases such as nitrogen and HFC-227ea suppress combustion by reducing oxygen concentration. Monitoring oxygen content can evaluate the oxygen suppression effect of these gases.

[0119] (2) Understand the combustion environment: By monitoring the oxygen content, we can understand the oxygen supply situation of the combustion environment, which provides an important reference for evaluating the fire resistance performance of the cable.

[0120] 3. Heat flow

[0121] Rationale: Heat flow is a key parameter for evaluating a cable's thermal response in a fire. A heat flow tester can measure the heat flow of the cable's surface and provide insights into the cable's heat conduction during a fire.

[0122] Purpose:

[0123] (1) Evaluate the thermal conductivity of cables: In a fire, cables transfer heat to the surrounding environment. The thermal conductivity of cables can be evaluated by measuring the heat flow.

[0124] (2) Monitoring fire heat release: Understanding the heat release of a fire helps to evaluate the fire resistance and fire protection effect of cables in a fire.

[0125] Although the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, utilize the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A fire detection and evaluation device for an inflatable composite high-voltage cable, characterized by: The invention comprises a lead seal (2), a monitoring device and a controller (5), wherein the controller (5) is electrically connected to the monitoring device, the lead seal (2) is used to be arranged at both ends of a cable body (1) and to seal the cable body (1), the monitoring device comprises a collection component and an air supply component (3), the air supply component (3) is used to communicate with the interior of the cable body (1) and to inflate air into the cable body (1), and the collection component is used to monitor and collect experimental data.

2. The fire detection and evaluation device for an inflatable composite high-voltage cable according to claim 1, characterized in that: It also includes a communication pipe (6), which is used to connect the air supply component (3) with the interior of the cable body (1).

3. The fire detection and evaluation device for an inflatable composite high-voltage cable according to claim 2, characterized in that: The collection component further comprises a flow meter (7), and the flow meter (7) is located on the communicating pipe (6).

4. The fire detection and evaluation device for an inflatable composite high-voltage cable according to claim 2, characterized in that: The collection component further comprises a pressure gauge (8), and the pressure gauge (8) is located on the connecting pipe (6).

5. The fire detection and evaluation device for an inflatable composite high-voltage cable according to any one of claims 1 to 4, characterized in that: The acquisition component further comprises a signal acquisition component (4), and the signal acquisition component (4) is used to detect the internal air pressure of the acquisition cable body (1).

6. The fire detection and evaluation device for an inflatable composite high-voltage cable according to any one of claims 1 to 4, characterized in that: It also includes a combustion cabinet (12), the lead seal (2) is located inside the combustion cabinet (12), and the air supply component (3) is located outside the combustion cabinet (12).

7. The fire detection and evaluation device for an inflatable composite high-voltage cable according to claim 6, characterized in that: The acquisition component further comprises an oxygen detector (9), a heat flow tester (10) and a thermometer (11) located in the combustion cabinet (12); the oxygen detector (9) is used to detect the oxygen content in the combustion cabinet (12); the heat flow tester (10) is used to detect the heat flow near the cable body (1); and the thermometer (11) is used to detect the flame temperature in the combustion cabinet (12).

8. The fire detection and evaluation device for an inflatable composite high-voltage cable according to claim 7, characterized in that: The oxygen detector (9) is a probe-lance type oxygen gas detector.

9. A fire detection and evaluation method for an inflatable composite high-voltage cable, characterized by: The fire detection and evaluation device for an inflatable composite high-voltage cable according to any one of claims 1 to 8 is used, including evaluating the internal fire condition of the cable body (1) and / or evaluating the external fire condition of the cable body (1).

10. The fire protection detection and evaluation method for an inflatable composite high-voltage cable according to claim 9, characterized in that: The method of evaluating the fire situation inside the cable body (1) comprises the following steps: A1. Seal both ends of the cable body (1) with lead seals (2) and install the monitoring equipment; A2. Open the gas supply component (3) to fill the cable body (1) with gas, and the collection component records and collects experimental data; A3. Evaluate the fire resistance of the cable body (1) based on the recorded experimental data.

11. The fire detection and evaluation method for an inflatable composite high-voltage cable according to claim 10, characterized in that: The experimental data include gas flow rate and gas flow rate.

12. The fire protection detection and evaluation method for an inflatable composite high-voltage cable according to claim 9, characterized in that: The evaluation of the external fire condition of the cable body (1) comprises the following steps: B1. Seal both ends of the cable body (1) with lead seals (2) and install the monitoring equipment; B2. Open the gas supply component (3) to fill the cable body (1) with gas, burn the cable body (1) with flame, and use the acquisition component to record and collect experimental data; B3. Evaluate the fire resistance of the cable body (1) based on the recorded experimental data.

13. The fire detection and evaluation method for an inflatable composite high-voltage cable according to claim 12, characterized in that: The experimental data include oxygen content, heat flux and flame temperature.

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