Fire point positioning and nozzle starting control method and device for automatic water spraying fire extinguishing

Abstract

The invention provides a fire point positioning and nozzle starting control method and device for automatic water spraying extinguishment, and the method comprises the following steps: obtaining monitoring data when a fire occurs in an application scene, the monitoring data comprising an environment temperature, a temperature of each nozzle, a fire heat release rate, and a height from the nozzle to the ground; preliminarily judging the position of a fire point and defining the position as a first fire position by comparing the temperature of each nozzle; constructing a horizontal distance matrix from a plurality of nozzles around the first fire position to the fire point according to the positioning model, and solving the horizontal distance matrix to obtain horizontal distances from the plurality of nozzles to the fire point so as to determine the actual position of the fire point; and according to the principle that the fire point is closest, nozzles around the actual position of the fire point are controlled to be started to spray water to extinguish fire. The position of a fire point can be effectively determined, the sprayers around the fire point are started in time for water spraying and fire extinguishing, fire spreading is effectively controlled, and the purpose of extinguishing early and small fire of the automatic water spraying and fire extinguishing system is achieved.

Description

Technical Field

[0001] The invention relates to the field of fire extinguishing, in particular to a method and a device for locating a fire point and controlling a sprinkler head for automatic water sprinkler fire extinguishing. Background Art

[0002] The automatic sprinkler system is an important firefighting facility that can automatically start and extinguish fires when a fire occurs. The automatic sprinkler system generally uses fire detectors for fire detection, but traditional fire detectors only determine that the fire is within the protection range of each detector based on the positioning chip of each fire detector, and cannot determine the exact position relationship between the fire detector and the fire point. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a method for locating the fire point and controlling the nozzle activation of an automatic sprinkler fire extinguishing system, which effectively controls the spread of the fire by determining the location of the fire point and activating the nozzles adjacent to the fire point.

[0004] To achieve the above objectives, the present invention provides a method for locating the fire point and controlling the start of sprinkler nozzles for automatic water sprinkler fire extinguishing, comprising the following steps: obtaining monitoring data when a fire occurs in an application scenario, the monitoring data including the ambient temperature, the temperature at each sprinkler nozzle, the fire heat release rate, and the height from the sprinkler nozzle to the ground; preliminarily determining the location of the fire point by comparing the temperatures at each sprinkler nozzle and defining it as the first fire location; constructing a horizontal distance matrix from multiple sprinklers around the first fire location to the fire point based on a positioning model, solving the horizontal distance matrix, obtaining the horizontal distance from the multiple sprinklers to the fire point, and then determining the actual location of the fire point; based on the principle of the closest fire point, controlling the start of sprinklers around the actual location of the fire point to spray water for fire extinguishing. The positioning model is r i =Q[β / h(T i -T ∞ )] 3 / 2 , where r i is the horizontal distance from the ith nozzle to the fire point, T ∞ is the ambient temperature, Q is the fire heat release rate, H is the height from the sprinkler to the ground, T i is the temperature at the i-th nozzle, β is the radius coefficient, and 5<β<18.

[0005] By comparing the temperatures at the various nozzles, the location of the ignition point is preliminarily determined and defined as the first ignition location, and the following steps are also included:

[0006] In the first working condition, when the temperature at certain four nozzles is greater than the temperature at other nozzles, and the temperature difference at the certain four nozzles is less than or equal to the first threshold, the first fire position is the middle of the certain four nozzles; or,

[0007] In the second working condition, when the temperature at two nozzles is greater than the temperature at other nozzles, and the temperature difference at the two nozzles is less than or equal to the first threshold, and the temperature difference at the other four nozzles closest to the middle of the two nozzles is also less than or equal to the first threshold, the first fire position is the middle of the two nozzles; or,

[0008] In the third operating condition, when the temperature at a certain nozzle is the highest, and the temperature difference at the other four nozzles closest to the certain nozzle is less than or equal to the first threshold, the first fire position is close to the certain nozzle or directly below the certain nozzle.

[0009] The method of controlling and starting the sprinklers around the actual location of the fire point to spray water to extinguish the fire based on the principle of being closest to the fire point also includes: in the first working condition, starting the four sprinklers; in the second working condition, starting the two sprinklers and any two sprinklers among the other four sprinklers closest to the two sprinklers; in the third working condition, starting the certain sprinkler or starting the certain sprinkler and starting the other four sprinklers closest to the certain sprinkler.

[0010] The step of constructing a horizontal distance matrix from a plurality of nozzles around the first fire location to the fire point according to the positioning model further includes: determining a value of a radius coefficient β, including: simulating a plurality of fire conditions with different ignition modes and different ignition locations in an application scenario, each of the fire conditions including a plurality of groups of tests; recording the monitoring data of the plurality of fire conditions; substituting the monitoring data into the following formula: β = (r / Q) 2 / 3 *(TT ∞ )*H, fit the radius coefficient β to obtain the fitted radius coefficients of the various fire conditions, wherein r is the horizontal distance from the nozzle to the ignition point, in the simulation case, r is a known condition, and T is the temperature at the nozzle; calculate the average value of the fitted radius coefficients of multiple groups of tests for each ignition position under different ignition modes; normalize the average values ​​under all ignition modes of a certain ignition position as the final radius coefficient of the ignition position.

[0011] The different ignition positions include: directly below the nozzle, close to the nozzle, between two nozzles and between four nozzles; the different ignition methods include cigarette butt ignition, electric spark ignition, heating wire ignition and welding slag ignition.

[0012] The method of determining the value of the radius coefficient β also includes: averaging the final radius coefficients of the three ignition positions, namely, near the nozzle, between two nozzles, and between four nozzles, and defining the final radius coefficient as the first radius coefficient; and defining the final radius coefficient of the ignition position directly below the nozzle as the second radius coefficient.

[0013] The positioning model is:

[0014]

[0015] Among them, β 1 represents the first radius coefficient, β 2 represents the second radius coefficient, r max Indicates the maximum protection distance of the sprinkler.

[0016] The method of obtaining the horizontal distance from the multiple nozzles to the fire point and then determining the actual position of the fire point also includes: establishing an objective function through the coordinates of the multiple nozzles and the horizontal distance from the multiple nozzles to the fire point, and obtaining the optimal solution for the actual position of the fire point by numerically optimizing the objective function, wherein the objective function is the sum of the squares of the errors of the horizontal distance and the distance from the fire point to the multiple nozzles.

[0017] On the other hand, the present invention also provides a fire point positioning and sprinkler start control device for automatic water sprinkler fire extinguishing, which adopts the above-mentioned fire point positioning and sprinkler start control method for automatic water sprinkler fire extinguishing, and at least includes: a data acquisition module, which is used to obtain monitoring data when a fire occurs in the application scenario, and the monitoring data includes the ambient temperature, the temperature at each sprinkler, the heat release rate, and the height from the sprinkler to the ground; a first judgment module, which is used to preliminarily determine the location of the fire point by comparing the temperatures at each sprinkler and define it as the first fire location; a second judgment module, which is used to construct a horizontal distance matrix from multiple sprinklers around the first fire location to the fire location based on the positioning model, solve the horizontal distance matrix, obtain the horizontal distance from the multiple sprinklers to the fire location, and then determine the actual location of the fire location; a control module, which is used to control the sprinklers around the actual location of the fire location to spray water for fire extinguishing according to the principle of the closest fire location. The positioning model is r i =Q[β / H(T i -T ∞ )] 3 / 2 , where r i is the horizontal distance from the ith nozzle to the fire point, T ∞ is the ambient temperature, Q is the heat release rate, H is the height from the nozzle to the ground, T i is the temperature at the i-th nozzle, β is the radius coefficient, and 5<β<18.

[0018] The data acquisition module includes: a nozzle arrangement module, which is used to arrange the nozzles in a grid shape, wherein the grid is a square, a rectangle or a diamond; a temperature acquisition module, which is used to obtain temperatures at different heights using temperature measurement points arranged at each nozzle and at a first distance immediately below each nozzle.

[0019] On the other hand, the present invention also provides an electronic device, comprising: a memory for storing a computer program; a processor for executing the computer program to implement the fire point positioning and sprinkler start-up control method of the automatic sprinkler fire extinguishing.

[0020] On the other hand, the present invention also provides a computer-readable storage medium for storing a computer program; when the computer program is executed by a processor, the fire point positioning and sprinkler start-up control method of the automatic sprinkler fire extinguishing is implemented.

[0021] It can be seen from the above scheme that the advantages of the present invention are:

[0022] The positioning model can be used to effectively determine the location of the fire point, and the sprinklers around the fire point can be activated in time to spray water to extinguish the fire, effectively controlling the spread of the fire and achieving the goal of extinguishing the fire early and small. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of the method for locating the fire point and starting the sprinkler of the automatic sprinkler fire extinguishing of the present invention;

[0024] Figure 2 for Figure 1 Flow chart of step S20;

[0025] Figure 3 This is a schematic diagram of the nozzle arrangement;

[0026] Figure 4 This is the temperature diffusion diagram of the smoke plume when a fire occurs;

[0027] Figure 5 for Figure 1 Flow chart of step S30;

[0028] Figure 6a Provide a top view of the thermocouple arrangement;

[0029] Figure 6b Provide a front view of the thermocouple arrangement;

[0030] Figure 6c Provide a side view of the thermocouple arrangement;

[0031] Figure 7 Schematic diagram of the horizontal distance from the nozzle to the fire point calculated under different simulated working conditions;

[0032] Figure 8 Another flow chart of the method for locating the fire point and starting the sprinkler of the automatic sprinkler fire extinguishing of the present invention;

[0033] Fig. 9 It is a structural schematic diagram of the fire point positioning and sprinkler start control device of the automatic sprinkler fire extinguishing of the present invention;

[0034] Fig.10 for Fig. 9 The structural diagram of the data acquisition module;

[0035] Fig.11 It is a structural schematic diagram of the electronic device of the present invention;

[0036] Wherein, the reference numerals are:

[0037] 100-Sprinkler;

[0038] 101-fire point;

[0039] 102-thermocouple;

[0040] 200-Fire point positioning and sprinkler start control device for automatic sprinkler fire extinguishing;

[0041] 2000-data acquisition module;

[0042] 2000a- Nozzle arrangement module;

[0043] 2000b-temperature acquisition module;

[0044] 2001-first determination module;

[0045] 2002-second determination module;

[0046] 2003-Control module;

[0047] 300-Electronic equipment;

[0048] 30'-processor;

[0049] 31'- memory;

[0050] 310'-Computer programs;

[0051] 400 - ceiling;

[0052] 401-Wall;

[0053] 402-ground;

[0054] S10~S40, S200~S202, S300~S301-steps. DETAILED DESCRIPTION

[0055] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments to further understand the purpose, solution and effect of the present invention, but it is not intended to limit the scope of protection of the claims attached to the present invention.

[0056] References to "an embodiment", "another embodiment", "this embodiment", etc. in the specification refer to the embodiment being described which may include specific features, structures or characteristics, but not every embodiment must include these specific features, structures or characteristics. In addition, such expressions do not refer to the same embodiment. Furthermore, when describing specific features, structures or characteristics in conjunction with an embodiment, whether or not there is an explicit description, it is indicated that incorporating such features, structures or characteristics into other embodiments is within the knowledge of those skilled in the art.

[0057] Certain words are used in the specification and subsequent claims to refer to specific components or parts. People of ordinary skill in the art should understand that technical users or manufacturers can refer to the same component or part with different nouns or terms. This specification and claims do not use differences in names as a way to distinguish components or parts, but use differences in the functions of components or parts as the criteria for distinction. "Including" and "including" mentioned throughout the specification and claims are open-ended terms and should be interpreted as "including but not limited to". In addition, the word "connected" here includes any direct and indirect electrical connection means. Indirect electrical connection means include connection through other devices.

[0058] In order to improve the safety and reliability of the intelligent automatic sprinkler fire extinguishing system and achieve the purpose of extinguishing the fire early and small, through a large number of experimental studies, the present invention obtains the fire scale and temperature field calculation coefficients at the initial stage of the fire, so as to predict the location of the fire point, accurately determine the fire point, start the sprinkler heads adjacent to the fire point, effectively control the spread of the fire, and achieve early and small extinguishing of the fire.

[0059] Figure 1 A flowchart of a method for locating a fire point and starting a sprinkler for automatic water sprinkler fire extinguishing provided by an embodiment of the present invention, wherein the method comprises the following steps:

[0060] S10: Acquire monitoring data when a fire occurs in the application scenario;

[0061] S20: By comparing the temperatures at each nozzle, the location of the fire point is preliminarily determined and defined as the first fire location;

[0062] S30: constructing a horizontal distance matrix from multiple nozzles around the first fire location to the fire point according to the positioning model, solving the horizontal distance matrix, obtaining the horizontal distances from the multiple nozzles to the fire point, and then determining the actual position of the fire point;

[0063] S40: Based on the principle of being closest to the fire point, control and activate the sprinklers around the actual location of the fire point to spray water to extinguish the fire.

[0064] In step S10 , the monitoring data includes fire and environmental parameters such as the ambient temperature, the temperature at each sprinkler head, the fire heat release rate, and the height from the sprinkler head to the ground.

[0065] When the maximum temperature at the nozzle is at least 10℃ to 30℃ higher than the ambient temperature, it indicates that a fire has occurred. Figure 2 The steps shown preliminarily determine the first fire location, and step S20 also includes:

[0066] S200: In the first working condition, when the temperature at four nozzles is greater than the temperature at other nozzles, and the temperature difference at the four nozzles is less than or equal to the first threshold, the first fire position is the middle of the four nozzles;

[0067] S201: In the second working condition, when the temperature at two nozzles is greater than the temperature at other nozzles, and the temperature difference at the two nozzles is less than or equal to the first threshold, and the temperature difference at the other four nozzles closest to the middle of the two nozzles is also less than or equal to the first threshold, the first fire location is the middle of the two nozzles;

[0068] S202: The third working condition, when the temperature at a certain nozzle is the highest, and the temperature difference at the other four nozzles closest to the certain nozzle is less than or equal to the first threshold, the first fire position is close to the certain nozzle or directly below the certain nozzle.

[0069] Specifically, a temperature sensor, such as a thermocouple 102 ( Figures 6a to 6c The nozzles 100 are arranged in a grid shape, and the grid can be square, rectangular, diamond, etc. Figure 3 As shown, the dotted-line frame represents the ceiling 400 , and the spray heads 100 are arranged on the ceiling 400 , and the spray heads 100 are arranged in a square structure. Figure 3 The number "1" in the figure represents the first nozzle 100, the number "2" represents the second nozzle 100, and so on. Figure 3 In the description, 12 nozzles 100 are taken as an example, but the present invention does not limit the number and arrangement of the nozzles 100.

[0070] According to the temperature data detected by the temperature sensor 102 at the nozzle 100, the working condition and position of the ignition point 101 are preliminarily determined as follows:

[0071] Working condition 1, when the temperature T at the 5th, 6th, 8th, and 9th nozzles 5 , T 6 , T 8 , T 9 is greater than the temperature at other nozzles, and T 5 , T 6 , T 8 , T9 When the fire point 101 is close to the four nozzles, it means that the fire point 101 is in the center of the four nozzles. 5 、r 6 、r 8 、r 9 should be equal,;

[0072] Condition 2, when the temperature T 5 With T 8 Similar, while T 4 , T 6 , T 7 , T 9 When the two nozzles are close, it means that the fire point 101 is between the 5th and 8th nozzles. 5 and r 8 should be equal;

[0073] Condition 3: When the fire point is close to the 8th nozzle, T 8 The value is the highest, and the temperatures at the 5th, 7th, 9th, and 11th nozzles are similar, and r 8 <r 5 , r 8 <r 6 , r 8 <r 9 When r 8 When it is close to zero, that is, r 8 When it is less than 0.3 m, it is considered that the position of the fire point 101 is directly below the 8th nozzle.

[0074] The principle for judging whether two or four temperatures are similar is that the difference between the two temperatures is less than or equal to 2°C or the difference between any two of the four temperatures is less than or equal to 2°C.

[0075] In step S30, the positioning model is:

[0076] r i =Q[β / H(T i -T ∞ )] 3 / 2 (1)

[0077] where r i is the horizontal distance from the ith nozzle to the fire point, in meters; T ∞ is the ambient temperature, in °C; Q is the total heat release rate of the fire source at the time when the sprinkler is actuated, in kW; H is the height from the sprinkler to the ground, in m; T i is the gas temperature at the nozzle when the i-th nozzle is in operation, in °C, β is the radius coefficient, and 5<β<18. i is a positive integer, and in the present invention, i=1, 2, 3...12. However, this is not limiting.

[0078] Formula (1) of this positioning model is mainly applicable to small-scale fires in indoor flat-roof windless environments. The heat flux meter monitors the radiant heat, the thermocouple monitors the ambient temperature and the gas temperature at the nozzle when the nozzle is in operation, the stopwatch monitors the fire growth time, the ruler measures the horizontal radius r between the actual fire source and the nozzle, and the camera monitors the ignition time and the fire time point, the nozzle operation time, etc. All monitoring parameters are used to determine the correlation coefficient value in the horizontal distance relationship formula (1) between the fire point and the nozzle. Figure 4 The figure shows the temperature diffusion diagram of the smoke plume when a fire occurs. The radius of the fire smoke plume r is shown in the figure. b Increases with increasing altitude.

[0079] Specifically, according to formula (1) and the position of the fire point initially determined in step S20, a horizontal distance matrix from the 5th, 6th, 8th, and 9th nozzles to the fire point is established as follows:

[0080]

[0081] By solving the above horizontal distance matrix, we can get the actual location of the fire point.

[0082] Given the height H from the sprinkler to the ground and the ambient temperature T of the fire scene ∞ By determining the radius coefficient β and the fire heat release rate Q, the known parameters are substituted into the matrix (3) to obtain:

[0083]

[0084] Solve the matrix to get the distance from the fire point to the four nozzles, and further determine the exact location of the fire source.

[0085] Obtaining the horizontal distances from the multiple nozzles to the ignition point in step S30 and then determining the actual position of the ignition point also includes: establishing an objective function through the coordinates of the multiple nozzles and the horizontal distances from the multiple nozzles to the ignition point, and obtaining the optimal solution for the actual position of the ignition point by numerically optimizing the objective function.

[0086] Specifically, a nonlinear optimization scheme is used, and the goal is to find the fire point P(x,y) that satisfies the distance constraint. For example:

[0087] It is known that the coordinates of the four nozzles are (x i ,y i )i∈{5, 6, 8, 9}, the distances from the ignition point P(x, y) to the four nozzles are r 5 , r 6 , r 8 , r 9 , establish the objective function:

[0088]

[0089] Among them, F(x,y) represents the sum of squares of the errors between the known distance and the calculated distance.

[0090] The coordinates of the ignition point P(x,y) are iteratively updated through the numerical optimization method to find the x and y that minimize the sum of squared errors F(x,y). The fminsearch function of MATLAB is used to minimize the objective function to obtain the optimal solution P(x,y).

[0091] In engineering practice, based on fire cases and fire extension investigations, as well as big data records of automatic sprinkler fire extinguishing systems, the β value in formula (1) is gradually optimized to improve the accuracy of the positioning model.

[0092] like Figure 5 As shown, step S30 also includes the following steps: S300: Determine the value of the radius coefficient β.

[0093] The following is an example of a specific application scenario:

[0094] In the early stage of a fire in a room, the fire source releases a large amount of smoke, which rises vertically and spreads horizontally to the surrounding area in the form of circular waves after reaching the ceiling. In this process, flames appear and the temperature continues to rise. Thermocouples are used to monitor the temperature gradient changes at different locations of the fire scene. The measurement points are arranged as follows: Figures 6a to 6c , Figure 6a The numbers "1, 2, 3...39" in the figure represent the serial numbers of the thermocouples 102, and the words "thermocouples 19, 20, 21 (upper, middle, lower)" represent that thermocouple No. 19 is located at the upper side, thermocouple No. 20 is located in the middle, and thermocouple No. 21 is located at the lower side. The three thermocouples are spaced at the same interval, for example, one meter. A thermocouple 102 is arranged next to each nozzle 100 to monitor the temperature change of the nozzle in real time. A measuring point is arranged every one meter directly below the nozzle 100 to study the temperature gradient changes at different heights of the temperature field. More measuring points are arranged near the fire source (i.e., the ignition point 101) to study the temperature changes near the ignition point. The temperature changes at each moment when the smoke reaches the ceiling 400 are recorded by the mobile thermocouples No. 30 and No. 34 next to the fire source. When the fire source is directly below or close to the 8th nozzle, the temperature at the nozzle is recorded by thermocouples No. 14, No. 5, No. 11, No. 17 and No. 25; when the fire source is between the 5th and 8th nozzles, the temperature of thermocouples No. 11, 14, 3, 5, 22 and 25 is monitored; when the fire source is between the 5th, 6th, 8th and 9th nozzles, the temperature of thermocouples No. 11, 14th, 22 and 25 is mainly monitored. Before ignition, monitor the ambient temperature through any thermocouple and record the temperature T when the nozzle is in action for each set of test data i With ambient temperature T ∞ The difference between .

[0095] The radiation heat release rate is 0.3 times the total heat release rate. The test uses two heat flow meters to monitor the radiation heat release rate per unit time and convert it into the total heat release rate of the combustion material per unit time. The calculation is as follows:

[0096]

[0097] Where: q″—unit radiation heat flux to target combustibles, kW / m 2 ;

[0098] R—the distance between the heat flow meter and the target combustible material, m;

[0099] χ r —Thermal radiation efficiency: for general combustibles, the thermal radiation efficiency is 0.3;

[0100] Q—Total heat release rate of the fire source from the moment the sprinkler operates, kW.

[0101] In order to better study small-scale fires, the fire location accuracy was studied in a scenario with a floor height of about 3m, a fire heat release rate range of 20kW-300kW, an ignition source power range of 3W-500W, and a maximum temperature within 500℃. The fire entity test had 16 working conditions, and three parallel tests were conducted for each working condition. Two sets of data were recorded for each test, for a total of 72 sets of data. The monitoring data included the heat release rate at different times, the ceiling temperature when the sprinkler was actuated, the thermocouple temperature at the sprinkler, the sprinkler actuation time, the fire growth time, and the smoldering time. The test data was substituted into formula (6) to fit the radius coefficient, and the results are shown in Table 1.

[0102] β=(r / Q) 2 / 3 *(TT ∞ )*H (6)

[0103] Where β is the radius coefficient; Q is the total heat release rate of the fire source when the sprinkler is actuated, kW; r is the horizontal distance between the fire source (i.e., the ignition point) and the sprinkler, m; T is the gas temperature when the sprinkler is actuated, °C; T ∞ is the test environment temperature, ℃; H is the height of the fuel from the ceiling, m, and the nozzle is arranged on the ceiling.

[0104] Table 1: Fitting values ​​of radius coefficient β under different working conditions

[0105]

[0106] Conditions (1)-(4): The ignition method is cigarette butt ignition, simulating the ignition of cigarette butts in trash cans in high-rise buildings, and the ignition power is 3W-5W. The positions of the fire source (i.e., the starting point) are directly below the nozzle, close to a nozzle, between two nozzles, and between four nozzles. The igniter is 400g of crumpled paper and the burning material is 25kg of wood pile. The heat release rate measured by radiation heat, the actual fire source radius, and the ambient temperature measured before and after the thermocouple test are linearly fitted with the maximum fire temperature when the nozzle is started to obtain a new coefficient. The average fitting radius coefficient of condition (1) is 7.78, the average fitting radius coefficient of condition (2) is 13.05, the average fitting radius coefficient of condition (3) is 13.15, and the average fitting radius coefficient of condition (4) is 15.78.

[0107] Conditions (5)-(8): The ignition method is electric spark ignition, simulating fires caused by electrical short circuits in high-rise buildings, and the ignition power is 10W-20W. The fire source locations are directly below the nozzle, near a nozzle, between two nozzles, and between four nozzles. The igniter is 400g of crumpled paper and the burning material is 25kg of wood pile. The heat release rate measured by radiation heat, the actual fire source radius, and the ambient temperature measured before and after the thermocouple test are linearly fitted with the maximum fire temperature when the nozzle is started to obtain a new coefficient. The average fitting radius coefficient of condition (5) is 6.01, the average fitting radius coefficient of condition (6) is 13.50, the average fitting radius coefficient of condition (7) is 14.71, and the average fitting radius coefficient of condition (8) is 16.03.

[0108] Working conditions (9)-(12): The ignition method is electric heating wire ignition, simulating the fire caused by electric blankets in high-rise buildings, and the ignition power is 10W-20W. The fire source locations are directly below the nozzle, close to a nozzle, between two nozzles, and between four nozzles. The ignition material is 400g of crumpled paper and the combustion material is 25kg of wood pile. The heat release rate measured by radiation heat, the actual fire source radius, and the ambient temperature measured before and after the thermocouple test are linearly fitted with the maximum fire temperature when the nozzle is started to obtain a new coefficient. The average fitting radius coefficient of working condition (9) is 6.66, the average fitting radius coefficient of working condition (10) is 12.79, the average fitting radius coefficient of working condition (11) is 14.7, and the average fitting radius coefficient of working condition (12) is 14.53.

[0109] Working conditions (13)-(16): The ignition method is welding slag ignition, simulating the fire caused by welding slag during electric welding construction in high-rise buildings. The fire source locations are directly below the nozzle, near a nozzle, between two nozzles, and between four nozzles. The igniter is 400g of crumpled paper and the burning material is 25kg of wood pile. The heat release rate measured by radiation heat, the actual fire source radius, and the ambient temperature measured before and after the thermocouple test are linearly fitted with the maximum fire temperature when the nozzle is started to obtain a new coefficient. The average fitting radius coefficient of working condition (13) is 5.12, the average fitting radius coefficient of working condition (14) is 12.83, the average fitting radius coefficient of working condition (15) is 15.28, and the average fitting radius coefficient of working condition (16) is 13.25.

[0110] Under different ignition modes, the radius coefficient near a nozzle position is normalized to 13.04, the radius coefficient of the fire source point between two nozzles is normalized to 14.46, and the radius coefficient of the fire source point between four nozzles is normalized to 14.90. Since the environmental conditions of each group of tests are not uniform, such as the influence of factors such as ambient temperature and moisture content of the combustion material, the monitored temperature, heat release rate, combustion process, etc. will be slightly different, resulting in some deviations in the coefficients. Therefore, the radius coefficient is normalized, and the average value of all radius coefficients, 14.13, is taken as the unified radius coefficient value. When r / H≥0.18, the radius coefficient is 14.13 (that is, the first radius coefficient β 1 ), when the fire point is located directly below the nozzle, all the radius coefficients obtained by fitting this position are normalized, and the average value of 6.04 is selected as the uniform radius coefficient of this position. That is, when r / H<0.18, the radius coefficient is 6.04 (that is, the second radius coefficient β 2 ). Therefore, the positioning model is formula (7):

[0111]

[0112] Among them, T i —Gas temperature when the i-th nozzle is in action, °C;

[0113] T ∞ —Ambient temperature, °C;

[0114] Q—Total heat release rate of the fire source at the time of sprinkler operation (i.e., fire heat release rate), kW;

[0115] r i —Horizontal distance between the ith nozzle and the fire point, m;

[0116] H—Height between ceiling and fuel surface, m.

[0117] r max —Maximum protection distance of the sprinkler, m, r i ≤rmax .

[0118] Step S30 also includes the following steps:

[0119] S301: Calculate the fire heat release rate Q, calculate the horizontal distance between the sprinkler head and the fire point according to the positioning model, and compare it with the actual value to further determine the reliability of the positioning model.

[0120] Specifically, the fire heat release rate Q is determined by formula (8). In actual engineering, the fire growth coefficient α can be determined according to the specific burning material. Taking the wood pile fire as an example, the wood pile is taken as 0.00278 based on the known data, and t is the fire growth time. The calculation results are shown in Table 2. The error between the calculated and experimental fire heat release rates is less than 15%.

[0121] Q=αt 2 (8)

[0122] Where: Q—fire heat release rate, kW;

[0123] α—fire growth coefficient, kW / s 2 ; This value is determined based on known data or experimental data. The coefficients for different locations are usually 0.001 to 0.07Kw / s from slow fire to ultra-fast fire 2 .

[0124] t—fire growth time, s; start recording time based on the starting point after the temperature of the temperature sensor continuously rises.

[0125] Table 2 Heat release rate calculation error

[0126]

[0127]

[0128] In Table 2, “Qmeasured” represents the fire heat release rate actually measured in the test, and “Q” represents the calculated fire heat release rate.

[0129] After obtaining the fire heat release rate Q, the horizontal distance between the sprinkler head and the fire point is calculated according to the positioning model. The calculation results are shown in Tables 3, 4, 5, and 6. The calculated horizontal distance r 计算 The actual horizontal distance r 实际 The error between them is about 15%, and the error of the nozzle protection radius (i.e. protection distance) is within 0.4m, which verifies the feasibility of the positioning model. The positioning error is as follows Figure 7 shown. Figure 7 In the figure, the horizontal axis represents working conditions (1) to (16), and the vertical axis "radius" refers to the calculated horizontal distance from the nozzle to the fire point.

[0130] Table 3 Cigarette ignition location error at different fire source positions

[0131]

[0132]

[0133] Table 4 Spark ignition positioning error at different fire source positions

[0134]

[0135] Table 5 Heating wire ignition positioning error at different fire source positions

[0136]

[0137]

[0138] Table 6 Electric welding ignition positioning error at different fire source positions

[0139]

[0140] In step S40, after preliminary determination and accurate calculation based on the sensor temperature, the PID control logic is used according to the principle of the closest fire point to achieve precise control of the sprinkler. The "closest fire point principle" means that when a fire occurs, the fire extinguishing system or equipment should give priority to activating the fire extinguishing device or equipment closest to the fire point to achieve rapid and effective fire extinguishing.

[0141] Specifically, if Figure 8 As shown, in the first working condition, the four nozzles around the fire point are started; in the second working condition, the two nozzles closest to the fire point and any two nozzles among the other four nozzles with similar temperatures are started; in the third working condition, the nozzle closest to the fire point is started or four nozzles closest to the nozzle are added.

[0142] To facilitate understanding of the above embodiment, a specific application scenario of the above embodiment will be used as an example for description below:

[0143] Take the fire point located in the middle of four nozzles as an example. The space height H is known, and the temperature T at the 5th, 6th, 8th, and 9th nozzles is 5 , T 6 , T 8 , T 9 , ambient temperature T ∞ , radius coefficient β, fire heat release rate Q, substitute the known parameters into the following matrix. H = 2.3m, β = 14.13, T 8 =121℃, T 5 =118.4℃, T 6 =118.5℃, T 9 =119℃, T∞ =26.2℃, the fire heat release rate Q is calculated to be 119.98kW, so substituting it into the horizontal distance matrix yields:

[0144]

[0145] Actual radius (i.e. horizontal distance) r 5 =r 6 =r 8 =r 9 =2.12m, the error is less than 15%.

[0146]

[0147] Solve the horizontal distance matrix to get the horizontal distance from the fire point to the four nozzles, and further determine the exact location of the fire point. A nonlinear optimization scheme is used to find the fire point P(x,y) that meets the distance constraint.

[0148] (1) The coordinates of the four nozzles are known to be (x i ,y i )i∈{5,6,8,9}

[0149] The distances from the fire point P(x,y) to the four nozzles are r 5 , r 6 , r 8 , r 9

[0150] (2) Establish the objective function:

[0151]

[0152] Here, F(x,y) represents the sum of squares of the errors between the known distance and the calculated distance.

[0153] (3) The coordinates of the ignition point P(x, y) are iteratively updated through the numerical optimization method to find the x, y that minimizes the sum of squared errors F(x, y). The objective function is minimized using the fminsearch function of MATLAB to obtain the optimal solution P(x, y).

[0154] Here we use the above example matrix to obtain r 5 , r 6 , r 8 , r 9 As an example, substitute the point_position function and calculate:

[0155] Optimal Point:(0.0206,0.0206)

[0156] Objective Function Value:0.0324

[0157] Optimum: (0.0206, 0.0206), close to the center of the four nozzles, consistent with the example

[0158] The objective function value is 0.0324, which reflects the sum of the square errors between the actual calculated distance and the known distance. The value is small, indicating that the optimization result is very close to the actual data, but there is still a certain error.

[0159] When the calculated r 8 When the height is less than 0.3m, it can be determined that the fire point is located directly below the 8th nozzle. The calculation results are shown in Table 7. 8 <r 5 , r 8 <r 6 , r 8 <r 9 When r 5 =r 8 <r 6 / r 9 When r 5 =r 6 =r 8 =r 9 It can be determined that the fire point is located in the middle of the 5th, 6th, 8th and 9th nozzles. The calculation results are shown in Table 10.

[0160] Table 7 Calculation of the radius of the fire point directly below the 8th nozzle

[0161]

[0162]

[0163] Table 8 Calculation of the radius of the fire point close to the 8th nozzle

[0164]

[0165] Table 9 Calculation of the radius when the fire point is located between the 5th and 8th nozzles

[0166]

[0167]

[0168] Table 10 Calculation of the radius between the 5th, 6th, 8th and 9th nozzles where the fire started

[0169]

[0170]

[0171] The following is a device embodiment corresponding to the above method embodiment. This embodiment can be implemented in conjunction with the above embodiment. The relevant technical details mentioned in the above embodiment are still valid in this embodiment. In order to reduce repetition, they are not repeated here. Accordingly, the relevant technical details mentioned in this embodiment can also be applied in the above embodiment.

[0172] like Fig. 9 FIG. 1 is a schematic diagram of a structure of a fire point positioning and sprinkler start control device 200 for automatic sprinkler fire extinguishing provided by another embodiment of the present invention, comprising:

[0173] The data acquisition module 2000 is used to acquire monitoring data when a fire occurs in the application scenario, wherein the monitoring data includes the ambient temperature, the temperature at each nozzle, the heat release rate of the fire, and the height from the nozzle to the ground;

[0174] The first determination module 2001 is used to preliminarily determine the location of the ignition point by comparing the temperatures at each nozzle and define it as the first ignition location;

[0175] The second determination module 2002 is used to construct a horizontal distance matrix from multiple nozzles around the first fire location to the fire point according to the positioning model, solve the horizontal distance matrix, obtain the horizontal distances from the multiple nozzles to the fire point, and then determine the actual position of the fire point;

[0176] The control module 2003 is used to control the sprinklers around the actual location of the fire point to start water spraying to extinguish the fire according to the principle of the fire point being closest.

[0177] like Fig.10 As shown, the data acquisition module 2000 includes:

[0178] The nozzle arrangement module 2000a is used to arrange the nozzles in a grid shape. The grid is a square, a rectangle, or a diamond. The nozzle arrangement is as follows: Figure 3 shown.

[0179] The temperature acquisition module 2000b is used to acquire the temperature at different heights by using the temperature measurement points arranged at each nozzle and at a first distance directly below each nozzle. The temperature measurement points are arranged as follows: Figures 6a to 6c shown.

[0180] In addition, technicians in the relevant field can clearly understand that for the convenience and simplicity of description, the specific working process of the fire point positioning and sprinkler start control device 200 for automatic sprinkler fire extinguishing can refer to the corresponding process in the aforementioned automatic sprinkler fire extinguishing fire point positioning and sprinkler start control method embodiment, and will not be repeated here.

[0181] Fig.11The structure diagram of an electronic device 300 provided in an embodiment of the present invention. The electronic device 300 may specifically include: at least one processor 30' and at least one memory 31'. The memory 31' is used to store a computer program 310', which is loaded and executed by the processor 30' to implement the relevant steps in the method for locating the fire point and starting the sprinkler of the automatic sprinkler fire extinguishing disclosed in any of the above embodiments, such as Figure 1 or Figure 8 Steps shown.

[0182] In addition, the memory 31 ′ as a carrier for storing resources may be a read-only memory, a random access memory, a magnetic disk or an optical disk, etc., and the storage method may be temporary storage or permanent storage.

[0183] The computer program 310' may include computer programs capable of completing the fire point location and sprinkler start control method for automatic sprinkler fire extinguishing executed by the electronic device 3 in any of the aforementioned embodiments, and may further include computer programs capable of completing other specific tasks.

[0184] Another embodiment of the present invention further discloses a computer storage medium, wherein the computer storage medium stores computer executable instructions, and when the computer executable instructions are loaded and executed by a processor, the method steps of locating the fire point and starting the sprinkler for automatic sprinkler fire extinguishing disclosed in any of the above embodiments are implemented, such as Figure 1 or Figure 8 Steps shown.

[0185] In summary, the present invention calculates the horizontal distance from the nozzle to the fire point through the positioning model, thereby accurately determining the location of the fire point, activating the nozzles adjacent to the fire point, effectively controlling the spread of the fire, and achieving the purpose of extinguishing the fire early and small.

[0186] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which belong to the protection scope of the present invention.

Claims

1. A method for locating the fire point and starting the sprinkler for automatic water sprinkler fire extinguishing, characterized in that: The following steps are involved: Acquire monitoring data when a fire occurs in the application scenario, wherein the monitoring data includes the ambient temperature, the temperature at each nozzle, the fire heat release rate, and the height from the nozzle to the ground; By comparing the temperatures at the various nozzles, the location of the fire point is preliminarily determined and defined as the first fire location; Constructing a horizontal distance matrix from a plurality of nozzles around the first fire location to the fire point according to the positioning model, solving the horizontal distance matrix, obtaining the horizontal distances from the plurality of nozzles to the fire point, and then determining the actual position of the fire point; According to the principle of the nearest fire point, the sprinklers around the actual location of the fire point are controlled to start spraying water to extinguish the fire; Wherein, the positioning model is r i =Q[β / H(T i -T ∞ )] 3 / 2 , where r i is the horizontal distance from the ith nozzle to the fire point, T ∞ is the ambient temperature, Q is the fire heat release rate, H is the height from the sprinkler to the ground, T i is the temperature at the i-th nozzle, β is the radius coefficient, and 5<β<18.

2. The method for locating the fire point and starting the sprinkler for automatic sprinkler fire extinguishing according to claim 1, characterized in that: By comparing the temperatures at the nozzles, the location of the ignition point is preliminarily determined and defined as the first ignition location, and the following steps are also included: In the first working condition, when the temperature at certain four nozzles is greater than the temperature at other nozzles, and the temperature difference at the certain four nozzles is less than or equal to the first threshold, the first fire position is the middle of the certain four nozzles; or, In the second working condition, when the temperature at two nozzles is greater than the temperature at other nozzles, and the temperature difference at the two nozzles is less than or equal to the first threshold, and the temperature difference at the other four nozzles closest to the middle of the two nozzles is also less than or equal to the first threshold, the first fire position is the middle of the two nozzles; or, In the third operating condition, when the temperature at a certain nozzle is the highest, and the temperature difference at the other four nozzles closest to the certain nozzle is less than or equal to the first threshold, the first fire position is close to the certain nozzle or directly below the certain nozzle.

3. The method for locating the fire point and starting the sprinkler for automatic sprinkler fire extinguishing according to claim 2, characterized in that: According to the principle of the nearest fire point, controlling and starting the sprinklers around the actual position of the fire point to spray water to extinguish the fire also includes the following steps: In the first working condition, starting the four nozzles; In the second working condition, the two nozzles and any two nozzles among the other four nozzles closest to the middle of the two nozzles are started; In the third working condition, the certain nozzle is started or the certain nozzle and four other nozzles closest to the certain nozzle are started.

4. The method for locating the fire point and starting the sprinkler for automatic sprinkler fire extinguishing according to claim 1, characterized in that: The step of constructing a horizontal distance matrix from a plurality of nozzles around the first fire location to the fire point according to the positioning model further includes: determining a value of a radius coefficient β, including: Simulating multiple fire conditions with different ignition modes and different ignition positions in the application scenario, each of the fire conditions including multiple groups of tests; Recording the monitoring data of the plurality of fire conditions; Substitute the monitoring data into the following formula: β = (r / Q) 2 / 3 *(TT ∞ )*H, fitting the radius coefficient β to obtain the fitting radius coefficients of the various fire conditions, wherein r is the horizontal distance from the nozzle to the fire point, in the simulation case, r is a known condition, and T is the temperature at the nozzle; Calculate the average value of the fitting radius coefficient of multiple groups of tests at each ignition position under different ignition modes; The average values ​​of all ignition modes at a certain ignition position are normalized as the final radius coefficient of the ignition position.

5. The method for locating the fire point and starting the sprinkler for automatic water sprinkler fire extinguishing according to claim 4, characterized in that: The different ignition positions include: directly below the nozzle, close to the nozzle, between two nozzles and between four nozzles; the different ignition methods include cigarette butt ignition, electric spark ignition, heating wire ignition and welding slag ignition.

6. The method for locating the fire point and starting the sprinkler for automatic water sprinkler fire extinguishing according to claim 5, characterized in that: The determination of the value of the radius coefficient β further includes: The final radius coefficients of the three ignition positions, namely, near the nozzle, between two nozzles, and between four nozzles, are averaged and defined as the first radius coefficient; The final radius coefficient of the ignition position directly below the nozzle is defined as the second radius coefficient.

7. The method for locating the fire point and starting the sprinkler for automatic sprinkler fire extinguishing according to claim 6, characterized in that: The positioning model is: Wherein, β1 represents the first radius coefficient, β2 represents the second radius coefficient, and r max Indicates the maximum protection distance of the sprinkler.

8. The method for locating the fire point and starting the sprinkler for automatic sprinkler fire extinguishing according to claim 1, characterized in that: The obtaining of the horizontal distances from the plurality of nozzles to the ignition point and then determining the actual position of the ignition point also includes: An objective function is established through the coordinates of the multiple nozzles and the horizontal distances from the multiple nozzles to the ignition point. The objective function is numerically optimized to obtain the optimal solution for the actual position of the ignition point. The objective function is the sum of the squares of the errors of the horizontal distance and the distance from the ignition point to the multiple nozzles.

9. A fire point positioning and sprinkler start control device for automatic sprinkler fire extinguishing, characterized in that: The method for locating the fire point and controlling the start of the sprinkler for automatic fire extinguishing according to any one of claims 1 to 8 at least comprises: A data acquisition module is used to acquire monitoring data when a fire occurs in an application scenario, wherein the monitoring data includes the ambient temperature, the temperature at each nozzle, the heat release rate of the fire, and the height from the nozzle to the ground; A first determination module, used to preliminarily determine the location of the ignition point by comparing the temperatures at the various nozzles and define it as a first ignition location; A second determination module is used to construct a horizontal distance matrix from a plurality of nozzles around the first fire location to the fire point according to the positioning model, solve the horizontal distance matrix, obtain the horizontal distance from the plurality of nozzles to the fire point, and then determine the actual position of the fire point; A control module is used to control and start the sprinklers around the actual location of the fire point to spray water to extinguish the fire according to the principle of the fire point being closest to the fire point; The positioning model is r i =Q[β / H(T i -T ∞ )] 3 / 2 , where r i is the horizontal distance from the ith nozzle to the fire point, T ∞ is the ambient temperature, Q is the fire heat release rate, H is the height from the sprinkler to the ground, T i is the temperature at the i-th nozzle, β is the radius coefficient, and 5<β<18.

10. The fire point positioning and sprinkler start control device for automatic sprinkler fire extinguishing according to claim 9, characterized in that: The data acquisition module comprises: A nozzle arrangement module, used to arrange the nozzles in a grid shape, wherein the grid is a square, a rectangle or a diamond; The temperature acquisition module is used to acquire temperatures at different heights by using temperature measurement points arranged at each nozzle and at first distances directly below each nozzle.

11. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor is used to execute the computer program to implement the fire point positioning and sprinkler start control method of automatic sprinkler fire extinguishing as described in any one of claims 1 to 8.

12. A computer-readable storage medium, characterized in that: Used to store computer programs; when the computer program is executed by a processor, the method for locating the fire point and starting the sprinkler for automatic sprinkler fire extinguishing as described in any one of claims 1 to 8 is implemented.

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