Superfine dry powder automatic fire extinguishing method and system

Abstract

The invention discloses a superfine dry powder automatic fire extinguishing method and system, and the method comprises the following steps: collecting multi-source parameters of a monitoring area according to a preset time interval; based on the multi-source parameters, whether an ignition point exists in the monitoring area or not is judged, and if yes, the first environment temperature rising rate, the smoke concentration change gradient and the first flame energy ratio are calculated; according to the temperature rising rate, the smoke concentration change gradient and the flame energy ratio, the fire behavior grade of the ignition point is judged; based on the fire behavior grade, a superfine dry powder spraying device is controlled to conduct graded spraying fire extinguishing; after graded jet fire extinguishing is conducted, the second temperature rising rate and the second flame energy ratio of the ignition point are calculated according to the preset time interval; and whether the ignition point has a reburning risk or not is judged based on the second temperature rising rate and the second flame energy ratio, and if yes, the superfine dry powder jetting device is controlled to conduct supplementary jetting.

Description

Technical Field

[0001] The present invention relates to the technical field of fire prevention and control, and in particular to an ultra-fine dry powder automatic fire extinguishing method and system. Background Art

[0002] In fire prevention and control technology, dry powder fire extinguishing systems are widely used in industries such as industry, electricity, and transportation due to their high fire extinguishing efficiency and wide range of applications. Traditional dry powder fire extinguishing systems usually use conventional dry powder fire extinguishing agents such as sodium bicarbonate and ammonium phosphate, and use high-pressure gas to drive dry powder spray to cover the fire source. However, in actual applications, existing technologies mostly use one-time full-volume spraying or simple time-sequenced segmented spraying. Such methods cannot dynamically adjust the spray dosage and rhythm according to the fire situation, and are prone to excessive waste of fire extinguishing agents in the early stage or insufficient suppression dosage in the later stage. Summary of the invention

[0003] In order to solve the technical problems in the prior art that the spray dosage and rhythm cannot be dynamically adjusted according to the fire situation, which easily leads to excessive waste of fire extinguishing agent in the early stage or insufficient suppression dosage in the later stage, the present invention provides an ultra-fine dry powder automatic fire extinguishing method and system.

[0004] The technical solution adopted by the present invention is:

[0005] The first aspect of the present application provides an ultra-fine dry powder automatic fire extinguishing method, comprising the following contents:

[0006] Collect multi-source parameters of the monitoring area at preset time intervals; wherein the multi-source parameters include ambient temperature value, smoke concentration value, flame signal, air flow speed and air flow direction; determine whether there is a fire point in the monitoring area based on the multi-source parameters, and if there is a fire point, calculate the first ambient temperature increase rate, smoke concentration change gradient and first flame energy ratio; determine the fire level of the fire point according to the temperature increase rate, smoke concentration change gradient and flame energy ratio; control the ultra-fine dry powder injection device to perform graded injection fire extinguishing based on the fire level; after graded injection fire extinguishing, calculate the second temperature increase rate and the second flame energy ratio of the fire point at preset time intervals; determine whether there is a risk of re-ignition of the fire point based on the second temperature increase rate and the second flame energy ratio, and if there is a risk of re-ignition, control the ultra-fine dry powder injection device to perform additional injection.

[0007] Preferably, the determination of whether there is a fire point in the monitoring area based on the multi-source parameters includes the following contents: comparing the collected ambient temperature value with the preset temperature threshold value, if the ambient temperature value is higher than the preset temperature threshold value and the duration exceeds the set time, it is determined that the temperature is abnormal; comparing the smoke concentration value with the preset smoke concentration threshold value, if the smoke concentration value is higher than the preset smoke concentration threshold value, it is determined that there is a smoke concentration abnormality; if a flame radiation signal in a specific wavelength range is detected, and the intensity of the flame radiation signal is greater than the set intensity threshold, it is confirmed that there is a flame signal; comparing the collected air flow velocity with the preset normal flow velocity range; if If the air flow velocity is greater than the upper limit of the preset normal flow velocity range, the air flow velocity is determined to be abnormal; the air flow direction is analyzed, the point position where the flame signal is detected is taken as the potential center, and a number of sampling points are determined around the potential center with a preset search radius, and the angle between the air flow direction of each sampling point and the potential center as the reference direction is calculated. If within the statistical time period, the angle of the sampling points exceeding the preset proportion meets the specific convergence or divergence angle range conditions, the air flow direction is determined to be abnormal; when there are temperature abnormalities, smoke concentration abnormalities, flame signals, air flow velocity abnormalities, and air flow direction abnormalities at the same time, it is determined that there is a fire point in the monitoring area.

[0008] Preferably, the fire level of the ignition point determined according to the temperature rise rate, the smoke concentration change gradient and the flame energy ratio includes the following contents: presetting a plurality of temperature rise rate intervals, wherein the plurality of temperature rise rate intervals include a low temperature rise rate interval, a medium temperature rise rate interval and a high temperature rise rate interval; setting a plurality of smoke concentration change gradient intervals, wherein the plurality of smoke concentration change gradient intervals include a low smoke concentration change interval, a medium smoke concentration change interval and a high smoke concentration change interval; dividing a plurality of flame energy ratio intervals, wherein the plurality of flame energy ratio intervals include a low flame energy ratio interval, a medium flame energy ratio interval and a high flame energy ratio interval; if the temperature rise rate, the smoke concentration change gradient and If the flame energy ratios are all in the corresponding low range, the fire level is determined to be level one; if two parameters among the temperature rise rate, the smoke concentration change gradient and the flame energy are in the corresponding low range, and the other parameter is in the corresponding middle range, the fire level is determined to be level two; if one parameter among the temperature rise rate, the smoke concentration change gradient and the flame energy is in the corresponding low range, and both parameters are in the corresponding middle range, the fire level is determined to be level three; if one parameter among the temperature rise rate, the smoke concentration change gradient and the flame energy is in the corresponding high range, the fire level is determined to be level four; if at least two parameters among the temperature rise rate, the smoke concentration change gradient and the flame energy are in the corresponding high range, the fire level is determined to be level five.

[0009] Preferably, the step of controlling the ultrafine dry powder spraying device to perform graded spraying fire extinguishing based on the fire level includes the following contents:

[0010] When the fire level is determined to be level four or level five, the ultra-fine dry powder injection device is controlled to perform three-level pulse injection, releasing a fire extinguishing agent accounting for a first preset proportion of the total dose within a first preset time, and after a preset time interval, releasing the fire extinguishing agent accounting for a second preset proportion of the total dose in two batches; when the fire level is determined to be level three, the ultra-fine dry powder injection device is controlled to perform gradient boost injection, initially releasing a fire extinguishing agent accounting for a third preset proportion of the total dose, and then increasing the injection dose at a fixed proportion per unit time; when the fire level is determined to be level two, the ultra-fine dry powder injection device is controlled to release a fire extinguishing agent accounting for a fourth preset proportion of the total dose; wherein the fourth preset proportion is smaller than the third preset proportion, and the third preset proportion is smaller than the first preset proportion.

[0011] Preferably, the calculation of the second temperature rise rate and the second flame energy ratio of the ignition point according to the preset time interval includes the following contents: based on the preset time interval, collecting multiple ambient temperature values ​​and flame radiation intensity of the ignition point, and calculating the second temperature rise rate based on the multiple ambient temperature values ​​and the preset time interval; by calculating the average value of the flame radiation intensity and combining it with a preset flame energy ratio calculation model, the second flame energy ratio is obtained.

[0012] Preferably, judging whether there is a re-ignition risk at the ignition point based on the second temperature increase rate and the second flame energy ratio includes the following contents:

[0013] Pre-set the re-ignition risk threshold of the temperature rise rate and the re-ignition risk threshold of the flame energy ratio; compare the calculated second temperature rise rate with the preset temperature rise rate re-ignition risk threshold, and compare the calculated second flame energy ratio with the preset flame energy ratio re-ignition risk threshold; if the second temperature rise rate is greater than the temperature rise rate re-ignition risk threshold or the second flame energy ratio is greater than the flame energy ratio re-ignition risk threshold, it is determined that there is a re-ignition risk at the ignition point.

[0014] Preferably, if there is a risk of re-ignition, controlling the ultrafine dry powder injection device to perform supplementary injection includes the following contents: when it is determined that there is a risk of re-ignition, controlling the ultrafine dry powder injection device to perform a first supplementary injection with a preset basic dose; after the first supplementary injection, continuing to determine whether there is a risk of re-ignition, and if there is a risk of re-ignition, performing a second supplementary injection.

[0015] The second aspect of the present application provides an ultra-fine dry powder automatic fire extinguishing system, including a multi-source parameter acquisition module, the multi-source parameter acquisition module is used to collect multi-source parameters of the monitoring area at preset time intervals, the multi-source parameters including ambient temperature value, smoke concentration value, flame signal, air flow speed and air flow direction; a fire point judgment module, the fire point judgment module is used to judge whether there is a fire point in the monitoring area based on the multi-source parameters; a first calculation module; if there is a fire point, the calculation module is used to calculate the first ambient temperature rise rate, the smoke concentration change gradient and the first flame energy ratio; a fire level judgment module, the fire level judgment module is used to judge the fire level according to the temperature rise rate , smoke concentration change gradient and flame energy ratio to judge the fire level of the ignition point; a graded injection control module, the graded injection control module is used to control the ultra-fine dry powder injection device to perform graded injection fire extinguishing based on the fire level; a second calculation module, after the graded injection fire extinguishing, the second calculation module is used to calculate the second temperature rise rate and the second flame energy ratio of the ignition point according to a preset time interval; a re-ignition risk judgment module, the re-ignition risk judgment module is used to judge whether there is a re-ignition risk at the ignition point based on the second temperature rise rate and the second flame energy ratio; a supplementary injection control module, if there is a re-ignition risk, the supplementary injection control module is used to control the ultra-fine dry powder injection device to perform supplementary injection.

[0016] The beneficial effects of the present invention are at least one of the following: In response to the problem that traditional methods cannot be dynamically adjusted according to the fire situation, the present application calculates the temperature rise rate, the smoke concentration change gradient and the flame energy ratio based on multi-source parameters, and then determines the fire level of the ignition point, providing a basis for subsequent fire extinguishing strategies.

[0017] This application uses ultra-fine dry powder spraying devices to control fire levels for graded spraying fire extinguishing, abandoning the traditional one-time full-volume spraying or simple time-sequence segmented spraying. Different spraying strategies are adopted according to different fire levels, such as three-level pulse spraying for level 4 or 5 fires, and gradient boost spraying for level 3 fires, etc., to achieve precise delivery of fire extinguishing agents, effectively avoid the problems of excessive waste of fire extinguishing agents in the early stage and insufficient amount of fire suppressant in the later stage, and improve the fire extinguishing efficiency and utilization rate of fire extinguishing agents.

[0018] After the graded spraying fire extinguishing, the second temperature rise rate and the second flame energy ratio are calculated to determine whether there is a risk of re-ignition at the ignition point. If there is, additional spraying is performed. It can timely detect and deal with the hidden dangers of re-ignition. Compared with traditional fire extinguishing methods, it further enhances the reliability of fire prevention and control, ensures that the fire is completely extinguished, and reduces the possibility of secondary fire hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of a method flow chart of Embodiment 1 of the present invention;

[0020] Figure 2 This is a system block diagram of Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0021] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0022] Embodiment 1

[0023] This embodiment provides an ultra-fine dry powder automatic fire extinguishing method, such as Figure 1 As shown, the following steps are included:

[0024] Step 1: Collect multi-source parameters of the monitoring area at preset time intervals; the multi-source parameters include ambient temperature value, smoke concentration value, flame signal, air flow speed and air flow direction.

[0025] For reference, the temperature sensor can be used to collect the ambient temperature value every 5 seconds, the smoke sensor can collect the smoke concentration value every 3 seconds, the flame detector can continuously monitor the flame radiation signal in a specific wavelength range, and the wind speed and direction sensor can collect the air flow speed and direction data every 4 seconds. You can use a high-precision thermistor temperature sensor with a detection accuracy of up to ±0.5℃; a smoke sensor based on the principle of light scattering can accurately detect smoke concentration; a flame detector can be selected that is sensitive to common fire flame wavelengths; and a wind speed and direction sensor can use a combination of a three-cup anemometer and a wind vane.

[0026] Step 2: determine whether there is a fire point in the monitoring area based on the multi-source parameters. If there is a fire point, execute step 3.

[0027] In a possible implementation manner, judging whether there is a fire point in the monitoring area based on the multi-source parameters includes the following contents:

[0028] Step 2.1, compare the collected ambient temperature value with the preset temperature threshold. If the ambient temperature value is higher than the preset temperature threshold and the duration exceeds the set time, it is determined to be a temperature abnormality.

[0029] For reference, the preset temperature threshold is 50°C and the set duration is 10 seconds. If the ambient temperature value collected by the temperature sensor is higher than 50°C and lasts for more than 10 seconds, it is judged as a temperature abnormality.

[0030] Step 2.2, comparing the smoke density value with a preset smoke density threshold value, if the smoke density value is higher than the preset smoke density threshold value, it is determined that there is a smoke density abnormality.

[0031] For reference, the preset smoke concentration threshold is 5 mg per cubic meter. When the smoke sensor detects that the smoke concentration value is higher than this threshold, it is determined that there is an abnormal smoke concentration.

[0032] Step 2.3: If a flame radiation signal within a specific wavelength range is detected and the intensity of the flame radiation signal is greater than a set intensity threshold, it is confirmed that a flame signal exists.

[0033] For reference, the flame detector detection wavelength range is set to 760-1100nm, and the intensity threshold is set to 1000lux. When the flame radiation signal intensity detected in this wavelength range is greater than 1000lux, the presence of a flame signal is confirmed.

[0034] Step 2.4, compare the collected air flow velocity with a preset normal flow velocity range; if the air flow velocity is greater than the upper limit of the preset normal flow velocity range, the air flow velocity is determined to be abnormal.

[0035] For reference, the preset normal flow rate range is 0-5m / s. When the air flow speed collected by the wind speed and direction sensor is greater than 5m / s, the air flow speed is judged to be abnormal.

[0036] Step 2.5, analyze the air flow direction, take the point position where the flame signal is detected as the potential center, determine several sampling points around the potential center with a preset search radius, calculate the angle between the air flow direction of each sampling point and the potential center as the reference direction, and if within the statistical time period, more than a preset proportion of the sampling point angles meet a specific convergence or divergence angle range condition, the air flow direction is determined to be abnormal.

[0037] For reference, the point where the flame signal is detected is taken as the potential center, the preset search radius is 5 meters, and 10 sampling points are determined within this radius. The preset statistical time period is 30 seconds. When more than 70% of the sampling point angles meet the convergence (0-30°) or divergence (150-180°) angle range conditions, the air flow direction is determined to be abnormal.

[0038] Step 2.6: When there are temperature anomalies, smoke density anomalies, flame signals, air flow velocity anomalies, and air flow direction anomalies at the same time, it is determined that there is a fire point in the monitoring area.

[0039] Step 3, calculating the first ambient temperature increase rate, the smoke concentration change gradient and the first flame energy ratio.

[0040] For reference, based on the collected multiple ambient temperature values, the formula (T2-T1) / Δt is used for calculation, where T2 is the temperature value at the next moment, T1 is the temperature value at the previous moment, and Δt is the time interval. The change in smoke concentration per unit time is calculated by the change in smoke concentration over time, and the flame radiation intensity and the preset reference radiation intensity are combined to obtain the flame energy ratio = average flame radiation intensity / preset reference radiation intensity.

[0041] Step 4: determine the fire level of the ignition point according to the temperature increase rate, smoke concentration change gradient and flame energy ratio.

[0042] In a possible implementation manner, judging the fire level of the ignition point according to the temperature increase rate, the smoke concentration change gradient and the flame energy ratio includes the following contents:

[0043] A plurality of temperature increase rate intervals are preset, wherein the plurality of temperature increase rate intervals include a low temperature increase rate interval, a medium temperature increase rate interval, and a high temperature increase rate interval.

[0044] For reference, the low range is a temperature rise of 0-5°C per minute, the middle range is a temperature rise of 5-15°C per minute, and the high range is a temperature rise of more than 15°C per minute.

[0045] A plurality of smoke concentration change gradient intervals are set, wherein the plurality of smoke concentration change gradient intervals include a smoke concentration change low interval, a smoke concentration change medium interval, and a smoke concentration change high interval.

[0046] For reference, the low range is 0-0.1mg / m3 / min increase in smoke concentration, the middle range is 0.1-0.5mg / m3 / min increase, and the high range is 0.5mg / m3 / min increase or more.

[0047] A plurality of flame energy ratio intervals are divided, wherein the plurality of flame energy ratio intervals include a low flame energy ratio interval, a medium flame energy ratio interval, and a high flame energy ratio interval.

[0048] For reference, the low range is 0-0.3, the middle range is 0.3-0.7, and the high range is above 0.7.

[0049] If the temperature rise rate, the smoke concentration change gradient and the flame energy ratio are all in the corresponding low range, the fire level is judged to be level one; if two parameters among the temperature rise rate, the smoke concentration change gradient and the flame energy are in the corresponding low range, and the other parameter is in the corresponding middle range, the fire level is judged to be level two; if one parameter among the temperature rise rate, the smoke concentration change gradient and the flame energy is in the corresponding low range, and both parameters are in the corresponding middle range, the fire level is judged to be level three.

[0050] If one of the parameters among the temperature rise rate, smoke concentration change gradient and flame energy is in the corresponding high range, the fire level is judged to be level four; if at least two of the parameters among the temperature rise rate, smoke concentration change gradient and flame energy are in the corresponding high range, the fire level is judged to be level five.

[0051] For reference, the first level of fire corresponds to a low degree of danger. At this time, the temperature rise rate, the smoke concentration change gradient and the flame energy ratio are all in the corresponding low range. The ambient temperature rises slowly, with a temperature rise of 0-5°C per minute; the smoke concentration does not increase significantly, with a smoke concentration increase of 0-0.1mg per cubic meter per minute; the flame energy ratio is low, at 0-0.3. The fire is in a very early stage, the fire is weak, the flammability is low, and the degree of spread is also low. There may only be slight signs of burning in a small area, and it usually does not pose a major threat to the surrounding environment.

[0052] Level 2 fire is of a lower danger level. Two parameters of the temperature rise rate, smoke density gradient, and flame energy are in the corresponding low range, and the other parameter is in the corresponding middle range. For example, the temperature rise rate may still be low, but the smoke density gradient or flame energy ratio enters the middle range. The fire has developed, the flammability has increased, and the degree of spread has also increased compared to level 1, but the overall situation is still within controllable range. The fire may spread in a local area, but the spread speed is relatively slow.

[0053] Level 3 fire is at a medium-risk level. One of the temperature rise rate, smoke concentration gradient and flame energy is in the corresponding low range, and two parameters are in the corresponding middle range. The ambient temperature rises faster, with a temperature increase of 5-15°C per minute; the smoke concentration increases significantly, with an increase of 0.1-0.5 mg per cubic meter per minute; the flame energy ratio is moderate, at 0.3-0.7. The fire enters the development stage, the flammability is high, the fire spreads faster, and it is easy to spread in a certain area. Effective fire-fighting measures need to be taken in time to control the fire.

[0054] Level 4 fire is a high-risk fire. One of the parameters of the temperature rise rate, smoke concentration gradient, and flame energy is in the corresponding high range. At this time, the fire situation is more serious, the flammability is high, and the fire spreads rapidly. It may threaten a larger area. It is necessary to invest more fire-fighting resources and adopt more powerful fire-fighting strategies. For example, a level 4 fire uses a three-stage pulse jet to quickly release a large amount of fire extinguishing agent to suppress the fire.

[0055] Level 5 fire corresponds to an extremely high degree of danger. At least two parameters of the temperature rise rate, smoke concentration gradient and flame energy are in the corresponding high range. The ambient temperature rises sharply, with a temperature rise of more than 15°C per minute; the smoke concentration increases sharply, with an increase of more than 0.5 mg per cubic meter per minute; the flame energy ratio is high, greater than 0.7. The fire is in a fierce burning stage, with a high degree of flammability, and the fire spreads very quickly, which may cause a large-scale fire and pose a great threat to the safety of life and property. The strongest fire-fighting measures must be taken immediately, such as the use of three-stage pulse jets in level 5 fires, to control the fire with all efforts to prevent it from further expanding.

[0056] Step 5: Based on the fire level, the ultrafine dry powder spray device is controlled to perform graded spray fire extinguishing.

[0057] In a possible implementation, controlling the ultrafine dry powder spray device to perform graded spray fire extinguishing based on the fire level includes the following contents:

[0058] When the fire level is determined to be level four or level five, the ultra-fine dry powder injection device is controlled to perform three-stage pulse injection, releasing a fire extinguishing agent accounting for a first preset proportion of the total dose within a first preset time, and after a preset time interval, releasing the fire extinguishing agent accounting for a second preset proportion of the total dose in two batches.

[0059] For reference, the first preset time is set to 0.5 seconds, the first preset ratio is adjusted to 50%, the preset time interval is 3 seconds, and the second preset ratio is 20%. 50% of the fire extinguishing agent is released within 0.5 seconds, and the remaining 20% ​​of the fire extinguishing agent is released twice after 3 seconds, and 30% of the fire extinguishing agent is reserved for possible re-ignition. This can not only quickly suppress the fire in the early stage, but also ensure sufficient fire extinguishing agent reserves in the future.

[0060] When the fire level is determined to be level three, the ultra-fine dry powder injection device is controlled to perform gradient boost injection, initially releasing a fire extinguishing agent accounting for the third preset proportion of the total dose, and then increasing the injection dose at a fixed proportion per unit time.

[0061] For reference, the third preset ratio is set at 15%, and the fixed ratio increase in injection dosage per unit time is set to 8% per second. During the fire extinguishing process, the dosage is adjusted dynamically according to the development of the fire, while taking into account the risk of subsequent re-ignition to avoid excessive use of fire extinguishing agents in the early stage.

[0062] It should be noted that level 4 and 5 fires are serious and extremely serious, with fierce fires and rapid spread. Level 3 pulse jetting can release 50% of the fire extinguishing agent within 0.5 seconds, quickly reducing the oxygen concentration and temperature around the fire source, and strongly suppressing the fire. For example, in a large warehouse fire, this jetting method can control the spread of the fire in a short period of time, buying time for subsequent rescue. The remaining 20% ​​of the fire extinguishing agent is then released twice at intervals of 3 seconds, which can continuously act on the fire source to prevent re-ignition.

[0063] Level 3 fires are relatively weaker than level 4 and 5 fires, but they still need to be effectively controlled. Initially releasing 15% of the fire extinguishing agent can initially suppress the fire. After that, the dosage increases by 8% per second, and the input of fire extinguishing agent can be dynamically adjusted according to the changes in the fire. This method not only avoids the waste caused by excessive injection in the early stage, but also flexibly increases the dosage as the fire develops, ensuring the fire extinguishing effect. For example, in the early stage of a fire in a small commercial place, the fire has not yet spread on a large scale. The use of gradient boost injection can not only effectively extinguish the fire, but also reasonably utilize the fire extinguishing agent resources.

[0064] When the fire level is determined to be level two, the ultra-fine dry powder spray device is controlled to release a fire extinguishing agent accounting for a fourth preset proportion of the total dose; wherein the fourth preset proportion is smaller than the third preset proportion, and the third preset proportion is smaller than the first preset proportion.

[0065] For reference, the fourth preset ratio is set at 8%, which controls the ultra-fine dry powder injection device to release 8% of the total dose of fire extinguishing agent. A certain amount of fire extinguishing agent is also reserved to prepare for possible re-ignition situations.

[0066] When the fire level is determined to be level one, the temperature rise rate, smoke concentration gradient and flame energy ratio are all in the corresponding low range, and the fire is in a very early stage, the fire is weak, the flammability is low, and the spread is low. At this time, the release of fire extinguishing agent is not started, only the fire-related data is recorded in detail, an early warning signal can be sent, and a special person or monitoring equipment can be arranged to closely monitor the fire site, and the fire can be extinguished with the fire extinguisher on site.

[0067] Step 6: After performing the graded jet fire extinguishing, calculate the second temperature rise rate and the second flame energy ratio of the ignition point according to the preset time interval.

[0068] In a possible implementation manner, calculating the second temperature increase rate and the second flame energy ratio of the ignition point according to a preset time interval includes the following contents:

[0069] Based on a preset time interval, multiple ambient temperature values ​​and flame radiation intensities of the ignition point are collected, and the second temperature rise rate is calculated based on the multiple ambient temperature values ​​and the preset time interval; the second flame energy ratio is obtained by calculating the average value of the flame radiation intensity and combining it with a preset flame energy ratio calculation model.

[0070] Step 7: determine whether there is a risk of re-ignition at the ignition point based on the second temperature increase rate and the second flame energy ratio. If there is a risk of re-ignition, execute step 8.

[0071] In a possible implementation manner, judging whether there is a re-ignition risk at the ignition point based on the second temperature increase rate and the second flame energy ratio includes the following contents:

[0072] The re-ignition risk threshold of the temperature increase rate and the re-ignition risk threshold of the flame energy ratio are preset.

[0073] For reference, the temperature rise rate re-ignition risk threshold is set at 3°C ​​per minute, and the flame energy ratio re-ignition risk threshold is set at 0.5.

[0074] The calculated second temperature increase rate is compared with a preset temperature increase rate re-ignition risk threshold, and the calculated second flame energy ratio is compared with a preset flame energy ratio re-ignition risk threshold.

[0075] If the second temperature increase rate is greater than the temperature increase rate re-ignition risk threshold or the second flame energy ratio is greater than the flame energy ratio re-ignition risk threshold, it is determined that the ignition point has a re-ignition risk.

[0076] Step 8, controlling the ultrafine dry powder spraying device to perform additional spraying.

[0077] In a possible implementation, if there is a risk of re-ignition, controlling the ultrafine dry powder injection device to perform supplementary injection includes the following:

[0078] When it is determined that there is a risk of re-ignition, the ultra-fine dry powder injection device is controlled to perform the first supplementary injection with a preset basic dose. After the first supplementary injection, it is continued to be determined whether there is a risk of re-ignition. If there is a risk of re-ignition, a second supplementary injection is performed.

[0079] For reference, when performing supplementary spraying, first calculate the total amount of fire extinguishing agent remaining after extinguishing fires of different fire levels in the early stage. When spraying in the early stage of a level 4 or 5 fire, 50% of the fire extinguishing agent is released within 0.5 seconds, and the remaining 20% ​​of the fire extinguishing agent is released twice after 3 seconds, leaving 30% of the fire extinguishing agent; the initial release of the third-level fire spray is 15%, and it increases by 8% per second until the fire changes; the second-level fire spray releases 8% of the fire extinguishing agent. According to the spatial volume of the area where the fire point is located, the effect of the early fire extinguishing, and the fire extinguishing efficiency of the fire extinguishing agent, the basic dose is determined to be 15% of the remaining amount based on the total amount of remaining fire extinguishing agent. Assuming that the initial total dose is 100 units, if the early stage is a level 4 or 5 fire, there are 30 units remaining after the early spraying, and the basic dose is 30×15%=4.5 units.

[0080] If there is still a risk of re-ignition after the first supplementary injection, the second supplementary injection dose is set to 1.5 times the basic dose. In the above example, the second supplementary injection dose is 4.5×1.5=6.75 units, which is a relative proportion calculated based on the total amount of remaining fire extinguishing agent, ensuring that the supplementary injection dose is reasonably allocated based on the previous injection situation to effectively deal with the risk of re-ignition. After each supplementary injection, the remaining fire extinguishing agent and the risk of re-ignition are re-evaluated so that the supplementary injection strategy can be flexibly adjusted later.

[0081] In summary, through the multi-source parameter collection in step 1, various high-precision sensors are used to collect ambient temperature values, smoke concentration values, flame signals, air flow speed and direction data at preset time intervals, providing a comprehensive basis for subsequent judgments. Step 2 is based on these parameters, through strict threshold setting and judgment logic, accurately determine the ignition point, avoid misjudgment and missed judgment, and achieve accurate early detection of fire. Step 3 calculates relevant parameters, and step 4 comprehensively judges the fire level based on multiple parameters and divides the fire into five levels. This grading method can comprehensively reflect the development trend and danger level of the fire, and provide accurate guidance for the formulation of subsequent fire extinguishing strategies. Step 5 adopts different injection strategies according to different fire levels. In the case of a first-level fire, the release of fire extinguishing agent is not initiated, only data is recorded and an early warning is issued, so as to make rational use of resources; in the case of a second-level fire, 8% of the fire extinguishing agent is released to initially control the fire; in the case of a third-level fire, gradient boost injection is used, with an initial release of 15% of the fire extinguishing agent and an increase of 8% per second, which can not only initially suppress the fire, but also dynamically adjust according to the changes in the fire to avoid waste; in the case of a fourth-level and fifth-level fire, three-level pulse injection is used, 50% of the fire extinguishing agent is released within 0.5 seconds, and the remaining 20% ​​is released in two batches after 3 seconds, so as to quickly suppress the fire and buy time for fire extinguishing. The injection strategies of each level cooperate with each other to achieve efficient fire extinguishing. Step 6 After the graded injection extinguishing, the second temperature rise rate and the second flame energy ratio are calculated; Step 7 The re-ignition risk is judged by comparing with the preset re-ignition risk threshold; Step 8 If there is a re-ignition risk, the basic dose and the secondary supplementary injection dose are determined according to the total amount of the remaining fire extinguishing agent in the previous period, and supplementary injection is performed. An effective mechanism for preventing and controlling re-ignition is formed to ensure that the fire is completely extinguished and the possibility of secondary hazards is reduced.

[0082] Embodiment 2

[0083] This embodiment provides an ultra-fine dry powder automatic fire extinguishing system, such as Figure 2As shown, it includes a multi-source parameter acquisition module, which is used to collect multi-source parameters of the monitoring area at preset time intervals, and the multi-source parameters include ambient temperature value, smoke concentration value, flame signal, air flow speed and air flow direction; a fire point judgment module, which is used to judge whether there is a fire point in the monitoring area based on the multi-source parameters; a first calculation module; if there is a fire point, the calculation module is used to calculate the first ambient temperature increase rate, the smoke concentration change gradient and the first flame energy ratio; a fire level judgment module, which is used to judge the fire level according to the temperature increase rate, the smoke concentration change gradient and the first flame energy ratio. and flame energy ratio to judge the fire level of the ignition point; a graded injection control module, the graded injection control module is used to control the ultra-fine dry powder injection device to perform graded injection fire extinguishing based on the fire level; a second calculation module, after the graded injection fire extinguishing, the second calculation module is used to calculate the second temperature rise rate and the second flame energy ratio of the ignition point according to a preset time interval; a re-ignition risk judgment module, the re-ignition risk judgment module is used to judge whether there is a re-ignition risk at the ignition point based on the second temperature rise rate and the second flame energy ratio; a supplementary injection control module, if there is a re-ignition risk, the supplementary injection control module is used to control the ultra-fine dry powder injection device to perform supplementary injection.

[0084] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. An ultra-fine dry powder automatic fire extinguishing method, characterized in that: Includes the following: Collect multi-source parameters of the monitoring area at preset time intervals; the multi-source parameters include ambient temperature value, smoke concentration value, flame signal, air flow speed and air flow direction; Based on the multi-source parameters, determine whether there is a fire point in the monitoring area, and if there is a fire point, calculate the first ambient temperature increase rate, the smoke concentration change gradient and the first flame energy ratio; Determine the fire level of the ignition point according to the temperature increase rate, smoke concentration change gradient and flame energy ratio; Based on the fire level, the ultrafine dry powder spray device is controlled to perform graded spray fire extinguishing; After performing the staged jet fire extinguishing, the second temperature rise rate and the second flame energy ratio of the ignition point are calculated according to the preset time intervals; Based on the second temperature increase rate and the second flame energy ratio, it is judged whether there is a risk of re-ignition at the ignition point. If there is a risk of re-ignition, the ultra-fine dry powder injection device is controlled to perform supplementary injection.

2. The method of automatic fire extinguishing using ultrafine dry powder according to claim 1, characterized in that: The method of judging whether there is a fire point in the monitoring area based on the multi-source parameters includes the following contents: Compare the collected ambient temperature value with the preset temperature threshold. If the ambient temperature value is higher than the preset temperature threshold and lasts longer than the set time, it is determined to be a temperature abnormality. The smoke concentration value is compared with a preset smoke concentration threshold value. If the smoke concentration value is higher than the preset smoke concentration threshold value, it is determined that there is a smoke concentration abnormality. If a flame radiation signal within a specific wavelength range is detected and the intensity of the flame radiation signal is greater than a set intensity threshold, then the presence of a flame signal is confirmed; Compare the collected air flow velocity with a preset normal flow velocity range; If the air flow velocity is greater than the upper limit of the preset normal flow velocity range, the air flow velocity is determined to be abnormal; The air flow direction is analyzed, and the point position where the flame signal is detected is taken as the potential center. A number of sampling points are determined around the potential center with a preset search radius, and the angle between the air flow direction of each sampling point and the reference direction of the potential center is calculated. If, within the statistical time period, the angle of the sampling points exceeding the preset proportion meets the specific convergence or divergence angle range conditions, the air flow direction is determined to be abnormal; When there are abnormal temperature, abnormal smoke concentration, flame signals, abnormal air flow speed, and abnormal air flow direction at the same time, it is determined that there is a fire point in the monitoring area.

3. The method of automatic fire extinguishing using ultrafine dry powder according to claim 2, characterized in that: The fire level of the ignition point determined according to the temperature rise rate, smoke concentration gradient and flame energy ratio includes the following: Presetting a plurality of temperature increase rate intervals, wherein the plurality of temperature increase rate intervals include a low temperature increase rate interval, a medium temperature increase rate interval, and a high temperature increase rate interval; Setting a plurality of smoke concentration change gradient intervals, wherein the plurality of smoke concentration change gradient intervals include a smoke concentration change low interval, a smoke concentration change medium interval, and a smoke concentration change high interval; Dividing a plurality of flame energy ratio intervals, wherein the plurality of flame energy ratio intervals include a low flame energy ratio interval, a medium flame energy ratio interval, and a high flame energy ratio interval; If the temperature rise rate, the smoke concentration gradient and the flame energy ratio are all in the corresponding low range, the fire level is determined to be level one; if two of the temperature rise rate, the smoke concentration gradient and the flame energy are in the corresponding low range and the other parameter is in the corresponding middle range, the fire level is determined to be level two; if one of the temperature rise rate, the smoke concentration gradient and the flame energy is in the corresponding low range and both parameters are in the corresponding middle range, the fire level is determined to be level three; If one of the parameters among the temperature rise rate, smoke concentration change gradient and flame energy is in the corresponding high range, the fire level is judged to be level four; if at least two of the parameters among the temperature rise rate, smoke concentration change gradient and flame energy are in the corresponding high range, the fire level is judged to be level five.

4. The method of automatic fire extinguishing using ultrafine dry powder according to claim 3, characterized in that: The control of the ultra-fine dry powder spray device to perform graded spray fire extinguishing based on the fire level includes the following contents: When the fire level is determined to be level 4 or level 5, the ultrafine dry powder spray device is controlled to perform three-stage pulse spraying, releasing a fire extinguishing agent accounting for a first preset proportion of the total dose within a first preset time, and after a preset time interval, releasing the fire extinguishing agent accounting for a second preset proportion of the total dose in two batches; When the fire level is determined to be level three, the ultra-fine dry powder spray device is controlled to perform gradient pressurization spraying, initially releasing a fire extinguishing agent accounting for a third preset proportion of the total dose, and then increasing the spray dose at a fixed proportion per unit time; When the fire level is determined to be level two, the ultra-fine dry powder spray device is controlled to release a fire extinguishing agent accounting for a fourth preset proportion of the total dose; wherein the fourth preset proportion is smaller than the third preset proportion, and the third preset proportion is smaller than the first preset proportion.

5. The method of automatic fire extinguishing using ultrafine dry powder according to claim 4, characterized in that: Calculating the second temperature increase rate and the second flame energy ratio of the ignition point according to the preset time interval includes the following contents: Based on a preset time interval, multiple ambient temperature values ​​and flame radiation intensities of the ignition point are collected, and the second temperature rise rate is calculated based on the multiple ambient temperature values ​​and the preset time interval; the second flame energy ratio is obtained by calculating the average value of the flame radiation intensity and combining it with a preset flame energy ratio calculation model.

6. The method of automatic fire extinguishing using ultrafine dry powder according to claim 5, characterized in that: The step of judging whether there is a re-ignition risk at the ignition point based on the second temperature increase rate and the second flame energy ratio includes the following: Presetting the re-ignition risk threshold of the temperature rise rate and the re-ignition risk threshold of the flame energy ratio; The calculated second temperature increase rate is compared with a preset temperature increase rate re-ignition risk threshold, and the calculated second flame energy ratio is compared with a preset flame energy ratio re-ignition risk threshold; If the second temperature increase rate is greater than the temperature increase rate re-ignition risk threshold or the second flame energy ratio is greater than the flame energy ratio re-ignition risk threshold, it is determined that the ignition point has a re-ignition risk.

7. The method of automatic fire extinguishing using ultrafine dry powder according to claim 6, characterized in that: If there is a risk of re-ignition, controlling the ultra-fine dry powder injection device to perform supplementary injection includes the following: When it is determined that there is a risk of re-ignition, the ultra-fine dry powder injection device is controlled to perform the first supplementary injection with a preset basic dose; After the first supplementary injection, it is further determined whether there is a risk of re-ignition. If there is a risk of re-ignition, a second supplementary injection is performed.

8. An ultra-fine dry powder automatic fire extinguishing system, characterized in that: include, A multi-source parameter acquisition module, which is used to collect multi-source parameters of the monitoring area at preset time intervals, wherein the multi-source parameters include ambient temperature value, smoke concentration value, flame signal, air flow speed and air flow direction; A fire point determination module, the fire point determination module is used to determine whether there is a fire point in the monitoring area based on the multi-source parameters; A first calculation module; if there is a fire point, the calculation module is used to calculate the first ambient temperature increase rate, the smoke concentration change gradient and the first flame energy ratio; A fire level judgment module, the fire level judgment module is used to judge the fire level of the ignition point according to the temperature increase rate, the smoke concentration change gradient and the flame energy ratio; A graded injection control module, the graded injection control module is used to control the ultra-fine dry powder injection device to perform graded injection fire extinguishing based on the fire level; A second calculation module, after performing staged jet fire extinguishing, the second calculation module is used to calculate a second temperature rise rate and a second flame energy ratio of the ignition point according to a preset time interval; a re-ignition risk judgment module, the re-ignition risk judgment module being used to judge whether there is a re-ignition risk at the ignition point based on the second temperature increase rate and the second flame energy ratio; A supplementary injection control module is used to control the ultrafine dry powder injection device to perform supplementary injection if there is a risk of re-ignition.

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