Cable interlayer fire early warning device and method based on pyrolysis particle sensor

Abstract

The invention discloses a cable interlayer fire early warning device and method based on a pyrolysis particle sensor, and belongs to the field of substation fire early warning, the cable interlayer fire early warning device comprises a monitoring host, a plurality of pyrolysis particle monitoring modules, a gas monitoring module, an environment monitoring module and an air exhaust module; the gas monitoring module, the plurality of pyrolysis particle monitoring modules and the environment monitoring module are electrically connected with the monitoring host separately, the gas extraction module is connected with the gas monitoring module, and air in a cable interlayer is extracted into the gas monitoring module by using the gas extraction module; the gas monitoring module monitors characteristic pyrolysis gas, and the characteristic pyrolysis gas and monitoring data of the pyrolysis particle monitoring module are jointly used for evaluating overheating defects and fire hazards in the cable interlayer; a cable interlayer fire early warning algorithm is built in the monitoring host, and the position of an overheating area in the cable interlayer and the fire risk are evaluated through monitoring data and the algorithm. According to the invention, the fire detection efficiency of important closed places such as cable interlayers can be improved, defects can be found earlier, and the accuracy is high.

Description

Technical Field

[0001] The present invention relates to the field of fire warning for transformer substations, and more specifically, to a cable interlayer fire warning device and method based on a pyrolysis particle sensor. Background Art

[0002] There are a large number of power cables in the cable mezzanine of the substation, and the space is relatively narrow and closed. Once a fire occurs, the loss will be huge.

[0003] At present, commonly used fire monitoring sensors are generally smoke alarms, cable-type temperature detectors, etc. There are the following disadvantages: low detection efficiency, untimely discovery, and technical problems that accuracy needs to be improved. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a cable interlayer fire warning device and method based on a pyrolytic particle sensor, which can improve the fire detection efficiency in closed and important places such as cable interlayers, discover defects earlier, have a low false alarm rate and a high accuracy rate.

[0005] The object of the present invention is achieved through the following solutions:

[0006] A cable interlayer fire warning device based on a pyrolytic particle sensor comprises: a monitoring host, a plurality of pyrolytic particle monitoring modules, a gas monitoring module, an environmental monitoring module and an exhaust module; the gas monitoring module, the plurality of pyrolytic particle monitoring modules and the environmental monitoring module are electrically connected to the monitoring host respectively, the exhaust module is connected to the gas monitoring module, and the exhaust module is used to extract the air in the cable interlayer into the gas monitoring module;

[0007] The gas monitoring module is used to monitor characteristic pyrolysis gases, and is used together with the monitoring data of the pyrolysis particle monitoring module to evaluate overheating defects and fire hazards in the cable interlayer; the monitoring host is equipped with a cable interlayer fire warning algorithm, which evaluates the location of the overheating area in the cable interlayer and the corresponding fire risk through monitoring data and algorithms.

[0008] Furthermore, the monitoring host is also used to display corresponding monitoring data, and to transmit data with the gas monitoring module, the pyrolysis particle monitoring module and the environment monitoring module via a bus.

[0009] Furthermore, the air extraction module includes an air extraction pump and a gas conduit.

[0010] Furthermore, the gas monitoring module includes a gas monitoring box and a characteristic gas monitoring sensor. The gas monitoring box is provided with an air inlet and an air outlet. The air inlet is connected to a one-way air inlet valve, the box body is connected to a pressure gauge, and the air outlet is connected to an air pump of an air extraction module through an electrically controlled air valve and a gas duct; the one-way air inlet valve is connected to the air outlet of each pyrolysis particle monitoring module through a gas duct.

[0011] Furthermore, the pyrolysis particle monitoring module includes a pyrolysis particle monitoring box and a pyrolysis particle sensor. The pyrolysis particle monitoring box is provided with an air inlet and an air outlet. The air outlet is connected by a one-way air inlet valve, and the air inlet is connected to a multi-channel gas duct.

[0012] Furthermore, the gas duct of each pyrolytic particle monitoring module is laid along the top of the cable interlayer, and the spacing between the ends of the gas duct of each pyrolytic particle monitoring module on the same cross-section is the same; the gas sampling port is at the same height from the ground of the cable interlayer; and the distance between each pyrolytic particle monitoring module along the length direction of the cable interlayer is the same.

[0013] Furthermore, the environmental monitoring module includes multiple air quality monitoring sensors and temperature and humidity monitoring sensors, which are installed at the entrance of the cable mezzanine, with one installed on one side of the substation at the entrance and one installed on one side of the cable mezzanine at the entrance.

[0014] A cable interlayer fire early warning method based on a pyrolytic particle sensor, based on the device as described in any one of the above, comprises the following steps:

[0015] Step S1, calibrating the particle detection time difference: placing the particle release source S on the ground directly below the sampling port of the first gas conduit, and recording the response times of the pyrolysis particle monitoring module 1, the pyrolysis particle monitoring module 2 and the pyrolysis particle monitoring module 3 as t111, t112, t113; placing S on the ground directly below the sampling port of the second gas conduit, and recording the response times of the pyrolysis particle monitoring module 1, the pyrolysis particle monitoring module 2 and the pyrolysis particle monitoring module 3 as t121, t122, t123; and so on, completing the particle detection time difference calibration;

[0016] Step S2: Determine the warning threshold of pyrolysis particles:

[0017] (1) Set the initial threshold RI:

[0018]

[0019] Among them, RI is the initial warning threshold of the pyrolytic particle sensor, x1 is the air quality detection result installed on the substation side of the cable mezzanine entrance, x2 is the air quality detection result installed on the cable mezzanine side of the cable mezzanine entrance, x3 is the temperature, x4 is the humidity, and p1-p12 are the coefficients to be determined;

[0020] (2) Based on the laboratory data and field measured data, the coefficients of p1-p12 are obtained after fitting;

[0021] (3) The particle swarm optimization algorithm is used to determine the dynamic threshold RD: the particle swarm optimization algorithm is used to optimize the p0-p12 coefficients on the calibrated data; the optimization objective function is the minimum square difference between RI and the actual test threshold RT of each calibration, that is, minΣ|RI-RT| 2 , the optimized coefficients are p0'-p12' respectively, then the optimized and adjusted dynamic threshold is set to:

[0022]

[0023] Step S3: Conduct early warning status assessment, including the following sub-steps:

[0024] Step 1, setting the pyrolysis particle warning threshold;

[0025] Step 2: determine whether the threshold is exceeded, if not, jump to step 1, if yes, proceed to the subsequent steps;

[0026] Step 3, determine whether the duration is greater than the duration threshold tδ; if yes, proceed to the subsequent steps; if not, after a delay of T_delay, jump to step 2;

[0027] Step 4, determine whether the condition is met: x1 exceeds the threshold and the duration is greater than tδ, if yes, go to step 5, if not, go to step 7;

[0028] Step 5, determine whether the condition is met: x2 exceeds the threshold and the duration is greater than tδ. If yes, go to step 6. If not, after a delay of T_delay, jump to step 2.

[0029] Step 6, determine whether the conditions are met: exceeding the threshold time sequence: the pyrolysis particles are less than x2 and x2 is less than x1, if yes, go to step 7, if not, after a delay of T_delay, jump to step 2;

[0030] Step 7, determine whether the condition is met: x2 exceeds the threshold and the duration is greater than tδ, if yes, proceed to step 8, if not, proceed to step 9;

[0031] Step 8, determine whether the conditions are met: exceeding the threshold time sequence: the pyrolysis particles are less than x2, if yes, go to step 9; if not, after a delay of T_delay, jump to step 2;

[0032] Step 9, determine whether the gas sensor responds, if yes, proceed to step 10, if not, proceed to step 11;

[0033] Step 10: Immediately call the police, notify the on-duty personnel through the Internet and SMS platform, conduct on-site investigation, and establish a load reversal plan for the cables in operation in the problem area;

[0034] Step 11: Call the police immediately and notify the on-duty personnel through the Internet and SMS platform, and conduct on-site inspection of the problem area if conditions permit.

[0035] Furthermore, the method for determining the problem area specifically includes the following sub-steps:

[0036] Assume that the third pyrolysis particle monitoring module is the first to issue an alarm, and the time when the pyrolysis particle sensor test value exceeds the threshold is T3, then there are the following situations:

[0037] Case 1: The pyrolytic particle monitoring values ​​of pyrolytic particle monitoring module 1, pyrolytic particle monitoring module 4 and pyrolytic particle monitoring module 5 do not change, or the time TX when the monitoring data increases satisfies TX-T3>t1m2-t1m1. The problem area is in the gas duct of the third pyrolytic particle monitoring module. t1m2 is the response time of pyrolytic particle monitoring module 2 when the release source is placed 1m below the sampling port of the gas duct. t1m1 is the response time of pyrolytic particle monitoring module 1 when the release source is placed 1m below the sampling port of the gas duct.

[0038] Case 2: The monitoring value of the pyrolysis particle monitoring module 4 increases, and the time when the data increases is T4. The pyrolysis particle monitoring module 1 and the pyrolysis particle monitoring module 5 do not change, or the monitoring data of the pyrolysis particle monitoring module 1 and the pyrolysis particle monitoring module 5 increase at a time TX, TX-T3>t1m3-t1m1, t1m3 is the response time of the pyrolysis particle monitoring module 3 when the release source is placed 1m below the sampling port of the gas duct;

[0039] The problem area is determined according to the following table 1:

[0040] Table 1

[0041] <h2 style=";text-align:left;direction:ltr">T4-T3 <t112-t111 <h2 style=";text-align:left;direction:ltr"> The gas conduit 31 and the gas conduit 41 correspond to the interval t112-t111 <T4-T3<t122-t121 The corresponding interval between gas conduit 31 and gas conduit 32 t122-t121 <T4-T3<t132-t131 The gas conduit 32 and the gas conduit 33 correspond to the interval …… ……

[0042] Case 3: The monitoring value of the pyrolysis particle monitoring module 4 increases. The time when the data increases is T4. The data of the pyrolysis particle monitoring module 1 increases. The data of the pyrolysis particle monitoring module 5 does not change. Then determine the problem area according to the following table 2:

[0043] Table 2

[0044]

[0045] Case 4: The monitoring value of the pyrolysis particle monitoring module 4 increases. The time when the data increases is T4. The data of the pyrolysis particle monitoring module 5 increases. The data of the pyrolysis particle monitoring module 1 does not change. Then determine the problem area according to the method in Table 3 below:

[0046] Table 3

[0047]

[0048] Furthermore, the coefficients of p1-p12 obtained after the fitting process are obtained by fitting the coefficients of p1-p12 using a least square method.

[0049] The beneficial effects of the present invention include:

[0050] Compared with traditional smoke warning systems, the present invention has higher sensitivity and faster response time, and can detect fire hazards early.

[0051] Compared with a single pyrolysis particle sensor, the present invention introduces pyrolysis gas detection of corresponding cable materials, which has higher accuracy and more reliable evaluation conclusions.

[0052] For cable interlayers with large spaces, the method of using multiple conduits to draw air into one box in the present invention can greatly reduce the number of sensors used. In addition, the location of overheating faults can be roughly located by using multiple conduits, reducing the time and effort required for defect detection.

[0053] The pyrolytic particle sensor is very sensitive to dust and is prone to false alarms. The present invention eliminates interference through environmental monitoring and greatly reduces the false alarm rate by setting a dynamic threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0055] Figure 1 is a structural block diagram of a device according to an embodiment of the present invention;

[0056] Figure 2 It is a schematic diagram (front view) of the installation of the device of the embodiment of the present invention;

[0057] Figure 3 It is a schematic diagram of the installation of the device of the embodiment of the present invention (left view);

[0058] Figure 4 The figure is a flowchart of the steps of the method according to the embodiment of the present invention. DETAILED DESCRIPTION

[0059] All features disclosed in all embodiments in this specification, or steps in all methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.

[0060] The specific implementation process of the present invention is as follows:

[0061] In a preferred embodiment, the present invention provides a cable interlayer fire warning device based on a pyrolytic particle sensor, which is actually a cable interlayer fire warning device based on a pyrolytic particle and a characteristic gas sensor, such as Figure 1 As shown, it specifically includes a monitoring host, a gas extraction module, a gas monitoring module, n pyrolysis particle monitoring modules and an environmental monitoring module.

[0062] The main function of the monitoring host is to display the corresponding monitoring data and have a built-in cable interlayer fire warning algorithm. Through the monitoring data and the corresponding algorithm, the location of the overheated area in the cable interlayer and the corresponding fire risk are evaluated. The host transmits data with the gas monitoring module, the pyrolysis particle monitoring module, and the environmental monitoring module in the form of a 485 bus.

[0063] The main function of the exhaust module is to extract the air in the cable interlayer into the monitoring device, which is composed of a high-power exhaust pump and a gas duct. The main function of the gas monitoring module is to monitor the characteristic pyrolysis gas, and jointly evaluate the overheating defects and fire hazards in the cable interlayer with the monitoring data of the pyrolysis particles. The gas monitoring module is mainly composed of a gas monitoring box and a characteristic gas monitoring sensor. The characteristic pyrolysis gas mainly considers the commonly used distribution cable materials and transmission cable materials. In the present invention, PE and PVC are mainly considered. According to the pyrolysis characteristics of the two materials in different temperature ranges, for example, PVC materials will pyrolyze in the range of 120℃-140℃ to produce characteristic pyrolysis gases such as CH4, C2H4, C2H6, C3H6, CH3Cl, CO and CO2. For example, PE or XLPE materials will also produce CH4, C2H4, C3H6, CH3CHO, CH3COCH3, CO and CO2. In the present invention, the gas monitoring sensor uses CH4, C2H2, C2H4, and C2H6 as characteristic gas monitoring sensors.

[0064] The gas monitoring box is equipped with an air inlet and an air outlet. The air inlet is connected to a one-way air inlet valve, the box is connected to a pressure gauge, and the air outlet is connected to a high-power air pump through an electric-controlled air valve and a gas conduit. The size of the box is not more than 0.3m*0.3m*0.3m.

[0065] The one-way air inlet valve is connected to the gas outlet of each pyrolysis particle monitoring module through a gas conduit.

[0066] The pyrolytic particle monitoring module mainly includes a pyrolytic particle monitoring box and a pyrolytic particle sensor. Optionally, the size of the pyrolytic particle box is not greater than 0.4m*0.4m*0.4m. At the same time, the pyrolytic particle monitoring box has an air inlet and an air outlet, the air outlet is connected by a one-way air inlet valve, and the air inlet is connected to a multi-channel gas duct. For example, for the pyrolytic particle monitoring module 1 shown in the figure, the names of the m ducts are 11, 12, 13...1m, and for the pyrolytic particle monitoring module 2, the names of the m ducts are 21, 22,...2m. The lengths of the multi-channel gas ducts of the pyrolytic particle monitoring module are equal.

[0067] Each pyrolysis particle monitoring module is installed as follows Figure 2 and Figure 3 As shown, the gas conduits are laid along the top of the cable interlayer, and the distance between the ends of the gas conduits (i.e., the gas sampling ports) of each pyrolytic particle monitoring module on the same section is the same, which is D. The height of the gas sampling ports from the ground of the cable interlayer is also the same. The distance between each pyrolytic particle monitoring module along the length of the cable interlayer is H.

[0068] The environmental monitoring module mainly includes multiple air quality monitoring sensors and temperature and humidity monitoring sensors. Its installation location is located at the entrance of the cable mezzanine, with one installed on one side of the entrance substation and one installed on one side of the entrance cable mezzanine.

[0069] In another preferred embodiment, the present invention provides a cable interlayer fire warning method based on a pyrolysis particle sensor, based on the device of the above embodiment. After the device is installed, the following steps are performed:

[0070] Step S1, first calibrate the particle detection time difference. Place a particle release source S (particles are released at a constant rate) on the ground directly below the gas duct sampling port 11, and record the response time of pyrolysis particle monitoring module 1, pyrolysis particle monitoring module 2 and pyrolysis particle monitoring module 3, t111, t112, t113. Place S on the ground directly below the gas duct sampling port 12, and record the response time of pyrolysis particle monitoring module 1, pyrolysis particle monitoring module 2 and pyrolysis particle monitoring module 3, t121, t122, t123. And so on.

[0071] Step S2: Determine the warning threshold of pyrolysis particles:

[0072] (1) Setting the initial threshold RI

[0073]

[0074] Among them, RI is the initial warning threshold of the pyrolytic particle sensor, x1 is the air quality detection result installed on the substation side of the cable mezzanine entrance, x2 is the air quality detection result installed on the cable mezzanine side of the cable mezzanine entrance, x3 is the temperature, and x4 is the humidity. p1-p12 are unknown coefficients.

[0075] (2) Based on laboratory data and other field measured data, the coefficients of p1-p12 are obtained by least squares fitting.

[0076] (3) Using particle swarm optimization algorithm to determine the dynamic threshold RD:

[0077] A conducts multiple calibration test data through the standard particle release source S (which can be carried out simultaneously with the calibration of the time difference in step 1), and B uses the particle swarm optimization algorithm to optimize the p0-p12 coefficients. The optimization objective function is the minimum square difference between RI and the actual test threshold RT of each calibration, that is, minΣ|RI-RT| 2 , the optimized coefficients are p0'-p12', and the optimized dynamic threshold is set to

[0078]

[0079] Step S3: Conduct early warning status assessment:

[0080] like Figure 4 As shown, step S3, conducting early warning status assessment, specifically includes the following sub-steps:

[0081] Step 1, setting the pyrolysis particle warning threshold;

[0082] Step 2: determine whether the threshold is exceeded, if not, jump to step 1, if yes, proceed to the subsequent steps;

[0083] Step 3, determine whether the duration is greater than the duration threshold tδ; if yes, proceed to the subsequent steps; if not, after a delay of T_delay, jump to step 2;

[0084] Step 4, determine whether the condition is met: x1 exceeds the threshold and the duration is greater than tδ, if yes, go to step 5, if not, go to step 7;

[0085] Step 5, determine whether the condition is met: x2 exceeds the threshold and the duration is greater than tδ. If yes, go to step 6. If not, after a delay of T_delay, jump to step 2.

[0086] Step 6, determine whether the conditions are met: exceeding the threshold time sequence: the pyrolysis particles are less than x2 and x2 is less than x1, if yes, go to step 7, if not, after a delay of T_delay, jump to step 2;

[0087] Step 7, determine whether the condition is met: x2 exceeds the threshold and the duration is greater than tδ, if yes, proceed to step 8, if not, proceed to step 9;

[0088] Step 8, determine whether the conditions are met: exceeding the threshold time sequence: the pyrolysis particles are less than x2, if yes, go to step 9; if not, after a delay of T_delay, jump to step 2;

[0089] Step 9, determine whether the gas sensor responds, if yes, proceed to step 10, if not, proceed to step 11;

[0090] Step 10: Immediately call the police, notify the on-duty personnel through the Internet and SMS platform, conduct on-site investigation, and establish a load reversal plan for the cables in operation in the problem area;

[0091] Step 11: Call the police immediately and notify the on-duty personnel through the Internet and SMS platform, and conduct on-site inspection of the problem area if conditions permit.

[0092] In the implementation steps above, the problem areas are identified as follows:

[0093] Assume that the third pyrolysis particle monitoring module is the first to issue an alarm, and the time when the pyrolysis particle sensor test value exceeds the threshold is T3, then there are the following situations:

[0094] (1) If the pyrolytic particle monitoring values ​​of the surrounding pyrolytic particle monitoring modules (the 1st, 4th, and 5th) do not change, or the time TX,TX-T3 of the monitoring data increases>t1m2-t1m1, then the problem area is 3m near the gas duct of the 3rd pyrolytic particle monitoring module.

[0095] (2) If the monitoring value of the pyrolysis particle monitoring module 4 increases, the time when the data increases is T4, 1 and 5 do not change, or the monitoring data of 1 and 5 increase at a time TX, TX-T3>t1m3-t1m1, then the problem interval is determined as follows:

[0096] Table 1

[0097] <h2 style=";text-align:left;direction:ltr">T4-T3 <t112-t111 <h2 style=";text-align:left;direction:ltr"> The gas conduit 31 and the gas conduit 41 correspond to the interval t112-t111 <T4-T3<t122-t121 The corresponding interval between gas conduit 31 and gas conduit 32 t122-t121 <T4-T3<t132-t131 The gas conduit 32 and the gas conduit 33 correspond to the interval …… ……

[0098] (3) The monitoring value of the pyrolysis particle monitoring module 4 increases, and the time when the data increases is T4. The data of the pyrolysis particle monitoring module 1 increases, and the data of the pyrolysis particle monitoring module 5 does not change. The problem interval is determined as follows:

[0099] Table 2

[0100]

[0101] (4) The monitoring value of the pyrolysis particle monitoring module 4 increases, and the time when the data increases is T4. The data of the pyrolysis particle monitoring module 5 increases, and the data of the pyrolysis particle monitoring module 1 does not change. The problem interval is determined as follows:

[0102] Table 3

[0103]

[0104] The units involved in the embodiments of the present invention may be implemented by software or hardware, and the units described may also be arranged in a processor. The names of these units do not, in some cases, limit the units themselves.

[0105] According to one aspect of an embodiment of the present invention, a computer program product or a computer program is provided, the computer program product or the computer program includes a computer instruction, and the computer instruction is stored in a computer-readable storage medium. A processor of a computer device reads the computer instruction from the computer-readable storage medium, and the processor executes the computer instruction, so that the computer device executes the method provided in the above various optional implementations.

[0106] As another aspect, an embodiment of the present invention further provides a computer-readable medium, which may be included in the electronic device described in the above embodiment; or may exist independently without being assembled into the electronic device. The above computer-readable medium carries one or more programs, and when the above one or more programs are executed by an electronic device, the electronic device implements the method described in the above embodiment.

Claims

1. A cable interlayer fire warning device based on pyrolysis particle sensor, characterized in that: include: Monitoring host, multiple pyrolysis particle monitoring modules, gas monitoring module, environmental monitoring module and exhaust module; The gas monitoring module, the plurality of pyrolysis particle monitoring modules, and the environment monitoring module are electrically connected to the monitoring host, respectively, and the air extraction module is connected to the gas monitoring module, and the air in the cable interlayer is extracted into the gas monitoring module by the air extraction module; The gas monitoring module is used to monitor characteristic pyrolysis gases, and is used together with the monitoring data of the pyrolysis particle monitoring module to evaluate overheating defects and fire hazards in the cable interlayer; the monitoring host is equipped with a cable interlayer fire warning algorithm, which evaluates the location of the overheating area in the cable interlayer and the corresponding fire risk through monitoring data and algorithms.

2. The cable interlayer fire warning device based on pyrolytic particle sensor according to claim 1 is characterized in that: The monitoring host is also used to display corresponding monitoring data and transmit data with the gas monitoring module, the pyrolysis particle monitoring module and the environment monitoring module through the bus.

3. The cable interlayer fire warning device based on pyrolytic particle sensor according to claim 1 is characterized in that: The air extraction module comprises an air extraction pump and a gas conduit.

4. The cable interlayer fire warning device based on pyrolytic particle sensor according to claim 1 is characterized in that: The gas monitoring module comprises a gas monitoring box and a characteristic gas monitoring sensor. The gas monitoring box is provided with an air inlet and an air outlet. The air inlet is connected to a one-way air inlet valve, the box body is connected to a barometer, and the air outlet is connected to an air pump of an air extraction module through an electrically controlled air valve and a gas conduit; the one-way air inlet valve is connected to the air outlets of each pyrolysis particle monitoring module through a gas conduit.

5. The cable interlayer fire warning device based on pyrolytic particle sensor according to claim 1 is characterized in that: The pyrolysis particle monitoring module comprises a pyrolysis particle monitoring box and a pyrolysis particle sensor. The pyrolysis particle monitoring box is provided with an air inlet and an air outlet. The air outlet is connected by a one-way air inlet valve, and the air inlet is connected to a multi-channel gas conduit.

6. The cable interlayer fire warning device based on pyrolytic particle sensor according to claim 5 is characterized in that: The gas duct of each pyrolytic particle monitoring module is laid along the top of the cable interlayer, and the spacing between the ends of the gas duct of each pyrolytic particle monitoring module on the same section is the same; the gas sampling port is at the same height from the ground of the cable interlayer; and the distance between each pyrolytic particle monitoring module along the length of the cable interlayer is the same.

7. The cable interlayer fire warning device based on pyrolytic particle sensor according to claim 1 is characterized in that: The environmental monitoring module includes multiple air quality monitoring sensors and temperature and humidity monitoring sensors, which are installed at the entrance of the cable mezzanine, with one installed on one side of the substation at the entrance and one installed on one side of the cable mezzanine at the entrance.

8. A cable interlayer fire warning method based on pyrolysis particle sensor, characterized in that: The device according to any one of claims 1 to 7 comprises the following steps: Step S1, calibrating the particle detection time difference: placing the particle release source S on the ground directly below the sampling port of the first gas conduit, and recording the response times of the pyrolysis particle monitoring module 1, the pyrolysis particle monitoring module 2 and the pyrolysis particle monitoring module 3 as t111, t112, t113; placing S on the ground directly below the sampling port of the second gas conduit, and recording the response times of the pyrolysis particle monitoring module 1, the pyrolysis particle monitoring module 2 and the pyrolysis particle monitoring module 3 as t121, t122, t123; and so on, completing the particle detection time difference calibration; Step S2: Determine the warning threshold of pyrolysis particles: (1) Set the initial threshold RI: Among them, RI is the initial warning threshold of the pyrolytic particle sensor, x1 is the air quality detection result installed on the substation side of the cable mezzanine entrance, x2 is the air quality detection result installed on the cable mezzanine side of the cable mezzanine entrance, x3 is the temperature, x4 is the humidity, and p1-p12 are the coefficients to be determined; (2) Based on the laboratory data and field measured data, the coefficients of p1-p12 are obtained after fitting; (3) The particle swarm optimization algorithm is used to determine the dynamic threshold RD: the particle swarm optimization algorithm is used to optimize the p0-p12 coefficients on the calibrated data; the optimization objective function is the minimum square difference between RI and the actual test threshold RT of each calibration, that is, minΣ|RI-RT| 2 , the optimized coefficients are p0'-p12' respectively, then the optimized and adjusted dynamic threshold is set to: Step S3: Conduct early warning status assessment, including the following sub-steps: Step 1, setting the pyrolysis particle warning threshold; Step 2: determine whether the threshold is exceeded, if not, jump to step 1, if yes, proceed to the subsequent steps; Step 3, determine whether the duration is greater than the duration threshold tδ; if yes, proceed to the subsequent steps; if not, after a delay of T_delay, jump to step 2; Step 4, determine whether the condition is met: x1 exceeds the threshold and the duration is greater than tδ, if yes, go to step 5, if not, go to step 7; Step 5, determine whether the condition is met: x2 exceeds the threshold and the duration is greater than tδ. If yes, go to step 6. If not, after a delay of T_delay, jump to step 2. Step 6, determine whether the conditions are met: exceeding the threshold time sequence: the pyrolysis particles are less than x2 and x2 is less than x1, if yes, go to step 7, if not, after a delay of T_delay, jump to step 2; Step 7, determine whether the condition is met: x2 exceeds the threshold and the duration is greater than tδ, if yes, go to step 8, if not, go to step 9; Step 8, determine whether the conditions are met: exceeding the threshold time sequence: the pyrolysis particles are less than x2, if yes, go to step 9; if not, after a delay of T_delay, jump to step 2; Step 9, determine whether the gas sensor responds, if yes, proceed to step 10, if not, proceed to step 11; Step 10: Immediately call the police, notify the on-duty personnel through the Internet and SMS platform, conduct on-site investigation, and establish a load reversal plan for the cables in operation in the problem area; Step 11: Call the police immediately and notify the on-duty personnel through the Internet and SMS platform, and conduct on-site inspection of the problem area if conditions permit.

9. The cable interlayer fire early warning method based on pyrolytic particle sensor according to claim 8 is characterized in that: The method for determining the problem area specifically includes the following sub-steps: Assume that the third pyrolysis particle monitoring module is the first to issue an alarm, and the time when the pyrolysis particle sensor test value exceeds the threshold is T3, then there are the following situations: Case 1: The pyrolytic particle monitoring values ​​of pyrolytic particle monitoring module 1, pyrolytic particle monitoring module 4 and pyrolytic particle monitoring module 5 do not change, or the time TX when the monitoring data increases satisfies TX-T3>t1m2-t1m1. The problem area is in the gas duct of the third pyrolytic particle monitoring module. t1m2 is the response time of pyrolytic particle monitoring module 2 when the release source is placed 1m below the sampling port of the gas duct. t1m1 is the response time of pyrolytic particle monitoring module 1 when the release source is placed 1m below the sampling port of the gas duct. Case 2: The monitoring value of the pyrolysis particle monitoring module 4 increases, and the time when the data increases is T4. The pyrolysis particle monitoring module 1 and the pyrolysis particle monitoring module 5 do not change, or the monitoring data of the pyrolysis particle monitoring module 1 and the pyrolysis particle monitoring module 5 increase at a time TX, TX-T3>t1m3-t1m1, t1m3 is the response time of the pyrolysis particle monitoring module 3 when the release source is placed 1m below the sampling port of the gas duct; The problem area is determined according to the following table 1: Table 1 Case 3: The monitoring value of the pyrolysis particle monitoring module 4 increases. The time when the data increases is T4. The data of the pyrolysis particle monitoring module 1 increases. The data of the pyrolysis particle monitoring module 5 does not change. Then determine the problem area according to the following table 2: Table 2 Case 4: The monitoring value of the pyrolysis particle monitoring module 4 increases. The time when the data increases is T4. The data of the pyrolysis particle monitoring module 5 increases. The data of the pyrolysis particle monitoring module 1 does not change. Then determine the problem area according to the method in Table 3 below: Table 3 10. The cable interlayer fire early warning method based on pyrolytic particle sensor according to claim 8, characterized in that: The coefficients of p1-p12 obtained after the fitting process are obtained by fitting the coefficients of p1-p12 using the least square method.

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