Intelligent monitoring system for explosive safety boundary based on multi-parameter response analysis

Abstract

The present application relates to the technical field of safety performance evaluation of energetic materials, in particular to an explosive safety boundary intelligent monitoring system based on multi-parameter response analysis. The system comprises a granulation mechanism and a sensor system, which comprises a thermocouple sensor, a force sensor and an electrostatic sensor. The thermocouple sensor, the force sensor and the electrostatic sensor are connected to a signal acquisition instrument and then connected to a computer, so that the real-time monitoring of the temperature, pressure and electrostatic accumulation trend during the granulation process can be realized through the computer. The determination of the safety boundary of the present application considers the statistical distribution characteristics of the response probability under multiple repeated tests, and the error of the obtained safety boundary is smaller. The intelligent monitoring system of the granulation process can accurately monitor the changes of the temperature, pressure and electrostatic quantity of the explosive in real time, and effectively avoid the safety hazards such as thermal runaway, mechanical overload and electrostatic discharge risk in the production process.

Description

Technical Field

[0001] This invention relates to the field of energetic material safety performance evaluation technology, specifically an intelligent monitoring system for explosive safety boundaries based on multi-parameter response analysis. Background Technology

[0002] In the research and development and production of energetic materials, accurately assessing their safety performance and ensuring the safety and controllability of the manufacturing process are core issues that the industry has long been concerned with. At present, the determination of the safety boundary of explosives mainly relies on sensitivity testing under single stimulus conditions, such as obtaining the critical stimulus threshold through impact sensitivity meters or friction sensitivity meters. However, such methods have significant limitations: (1) Traditional tests mostly use single tests with a fixed sample size (e.g., the 50% ignition probability method recommended by the United Nations), ignoring the statistical distribution characteristics of the response probability under repeated tests, resulting in a large error in the safety threshold; (2) Test data are mostly processed by linear interpolation or empirical formulas, lacking nonlinear fitting methods based on probabilistic statistical models, resulting in insufficient scientific validity of the safety threshold.

[0003] In the field of explosive granulation technology, existing granulation equipment generally suffers from insufficient safety monitoring capabilities. Although conventional granulation devices (such as rotary extrusion granulators) can achieve the formation of explosive particles, their monitoring systems have the following problems: (1) Thermocouple sensors are mostly arranged on the outer wall of the equipment or far away from the reaction zone, making it impossible to capture the local temperature rise caused by frictional heat generation in the granulation chamber in real time; (2) Pressure detection relies on overall torque monitoring, making it difficult to analyze the dynamic pressure pulsation characteristics of the contact area between the scraper and the screen. These problems make it easy for safety hazards such as thermal runaway and mechanical overload to occur during the production process. Summary of the Invention

[0004] This invention addresses the issue that traditional methods for determining the safety boundary of explosives rely on single experiments with fixed sample sizes, leading to significant errors in the safety threshold. Furthermore, in the field of explosive granulation processes, existing granulation equipment generally suffers from insufficient safety monitoring capabilities. This invention provides an intelligent monitoring system for the safety boundary of explosives based on multi-parameter response analysis.

[0005] This invention adopts the following technical solution: an intelligent monitoring system for explosive safety boundaries based on multi-parameter response analysis, including a granulation mechanism and a sensor system, wherein the sensor system includes:

[0006] Thermocouple sensors, force sensors, and electrostatic sensors;

[0007] Thermocouple sensors, force sensors, and electrostatic sensors are connected to a signal acquisition instrument and then connected to a computer, enabling real-time monitoring of temperature, pressure, and electrostatic accumulation during the granulation process.

[0008] In some embodiments, the monitored temperature is compared with the temperature safety boundary of the explosive. If the monitored temperature exceeds the temperature safety boundary, the explosive granulation process is in a dangerous state and an alarm is triggered immediately.

[0009] Based on the comparison between the monitored pressure and the safety boundaries of impact stimulation and friction stimulation, if the monitored pressure exceeds the safety boundaries of impact stimulation and friction stimulation, the explosive granulation process is in a dangerous state and an alarm is triggered immediately.

[0010] By comparing the monitored static electricity accumulation status with the safe boundary of static electricity stimulation, if the monitored static electricity accumulation status exceeds the safe boundary of static electricity stimulation, the explosive granulation process is in a dangerous state, and an alarm will be triggered immediately.

[0011] In some embodiments, the temperature safety boundary of the explosive is the initial temperature of the explosive's thermal decomposition.

[0012] In some embodiments, the initial temperature of thermal decomposition of the explosive sample is calculated through the following steps:

[0013] S11: Place the explosive sample in the crucible of the differential scanning calorimeter, record the heat flow curve, and extract the peak thermal decomposition temperature T. p ;

[0014] S12: Calculate activation energy E a :

[0015]

[0016] In the formula: It is the heating rate; Is the rate of heating of the explosive The peak decomposition temperature at time; A is the exponential factor; It is the activation energy; R is the gas constant;

[0017] S13: Calculate the initial temperature of thermal decomposition. :

[0018]

[0019] In the formula: This is the critical temperature for thermal explosion. It is the initial temperature of thermal decomposition; b, c, and d are constants.

[0020] In some embodiments, the differential scanning calorimeter has a heating rate of 5-20 °C / min and a test temperature range of 50-400 °C.

[0021] In some embodiments, the safety boundaries for impact stimulation and friction stimulation are obtained through the following steps:

[0022] Mechanical impact and friction with different stimuli were applied to the explosive samples. Each stimulus was repeated to obtain the scatter plot of impact stimulus-response probability and friction stimulus-response probability of the explosive samples.

[0023] Nonlinear curve fitting was performed on the scatter plots of impact stimulus-response probability and friction stimulus-response probability, respectively. The stimulus values ​​corresponding to the intersection points of the fitted curves and the horizontal axis were extracted as the safety boundaries of the explosives under impact or friction stimulation.

[0024] In some embodiments, the safe boundary for electrostatic stimulation is calculated through the following steps:

[0025] Electrostatic spark stimulation was applied to the explosive sample, and repeated experiments were conducted to obtain a scatter plot of electrostatic stimulation amount-response probability of the explosive sample.

[0026] Nonlinear curve fitting was performed on the scatter plot of electrostatic stimulation-response probability, and the stimulation value corresponding to the intersection of the fitted curve and the horizontal axis was extracted as the safety boundary of the explosive under electrostatic stimulation.

[0027] In some embodiments, the process of fitting the impact stimulus, friction stimulus, and electrostatic stimulus to obtain the safety boundary includes:

[0028] The stimulus-response probability data were imported into Origin software and nonlinear fitting was performed using the ExpDec1 model.

[0029] With a confidence level of 95%, the confidence interval of the fitted curve is calculated. The stimulus value corresponding to the intersection of the fitted curve and the horizontal axis is extracted as the safety boundary of the explosive under impact, friction or electrostatic stimulation. The stimulus value corresponding to a response probability of 2% is taken as the safety threshold of the explosive under impact, friction or electrostatic stimulation.

[0030] In some embodiments, the granulation mechanism includes:

[0031] Upper feed funnel;

[0032] A cylindrical tube is provided at the bottom of the upper feed hopper, and the bottom of the cylindrical tube is provided with a screen with a replaceable aperture.

[0033] Thermocouple sensors are installed on the side wall of the cylindrical tube, and the probe is inserted into the material area above the screen through a small hole in the side wall.

[0034] Force sensors are installed on the screen.

[0035] The lower forming funnel is located below the cylindrical tube.

[0036] In some embodiments, the electrostatic sensor is positioned to the side of the granulation mechanism, with the probe of the electrostatic sensor pointing towards the central axis of the cylindrical tube.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The safety boundary determination of this invention takes into account the statistical distribution characteristics of the response probability under repeated experiments, resulting in a smaller safety boundary error. The intelligent monitoring system for the granulation process can accurately monitor the temperature, pressure, and electrostatic changes of the explosive in real time, effectively avoiding safety hazards such as thermal runaway, mechanical overload, and electrostatic discharge risks during production. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the intelligent monitoring system for explosive safety boundaries based on multi-parameter response analysis according to the present invention;

[0040] Figure 2 This is a schematic diagram of the granulation mechanism of the present invention;

[0041] Figure 3 This is a graph showing the impact stimulus amount versus response probability.

[0042] Figure 4 This is a graph showing the friction stimulus amount versus the response probability.

[0043] Figure 5 This is a graph showing the electrostatic stimulus amount versus the response probability.

[0044] In the figure, 1-granulation mechanism, 1.1-upper feed hopper, 1.2-cylinder, 1.3-lower forming hopper, 2-signal acquisition instrument, 3-computer, 4-electrostatic sensor, 5-thermocouple sensor, 6-force sensor. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] like Figure 1 As shown, an intelligent monitoring system for explosive safety boundaries based on multi-parameter response analysis includes a granulation mechanism 1 and a sensor system, wherein the sensor system includes:

[0047] Thermocouple sensor 5, force sensor 6, and electrostatic sensor 4;

[0048] Thermocouple sensor 5, force sensor 6, and electrostatic sensor 4 are connected to signal acquisition instrument 2 and then connected to computer 3. Computer 3 enables real-time monitoring of temperature, pressure, and electrostatic accumulation during the granulation process.

[0049] like Figure 2 As shown, the granulation mechanism 1 includes:

[0050] Upper feed funnel 1.1;

[0051] A cylindrical tube 1.2 is provided at the bottom of the upper feed hopper 1.1, and the bottom of the cylindrical tube 1.2 is provided with a screen with a replaceable aperture.

[0052] Thermocouple sensor 5 is installed on the side wall of cylindrical tube 1.2, and the probe is inserted into the material area above the screen through a small hole on the side wall;

[0053] Force sensor 6 is installed on the screen;

[0054] The lower forming funnel 1.3 is located below the cylindrical tube 1.2.

[0055] The electrostatic sensor 4 is positioned to the side of the granulation mechanism 1, with the probe of the electrostatic sensor 4 pointing towards the central axis of the cylindrical tube 1.2.

[0056] Example 1: Structural Configuration of Granulation Process Monitoring Device

[0057] (1) Granulation mechanism

[0058] The upper feed hopper 1.1 is made of stainless steel, with an inlet diameter of 500mm, an outlet diameter of 300mm, and a height of 100mm. The outlet of the upper feed hopper 1.1 is connected to a cylindrical tube 1.2 with a diameter of 300mm and a height of 70mm. Below the cylindrical tube 1.2 is a stainless steel screen with replaceable aperture. The lower forming hopper 1.3 has an inlet diameter of 300mm, an outlet diameter of 160mm, and a height of 270mm.

[0059] (2) Sensor system

[0060] Thermocouple sensor 5: Located on the side wall of the cylindrical cylinder 1.2 connected to the outlet of the upper feed hopper 1.1, the probe is inserted into the material zone of the granulator through a small hole on the side wall.

[0061] Force sensor 6: Located on the screen, the force sensor 6 is flush with the screen.

[0062] Electrostatic sensor 4: It is placed on the side of the granulation mechanism 1 via a bracket, with the probe detection end pointing towards the central axis of the cylindrical tube 1.2.

[0063] (3) Data acquisition and control

[0064] All sensors are connected to signal acquisition unit 2 and then to computer 3. Computer software enables real-time monitoring of temperature, pressure, and static electricity accumulation during the granulation process. Safety boundaries are set as warning values; if a sensor detects that any value during production exceeds the safety boundary, an immediate warning is issued.

[0065] The monitored temperature is compared with the temperature safety boundary of the explosive. If the monitored temperature exceeds the temperature safety boundary, the explosive granulation process is in a dangerous state and an alarm is triggered immediately.

[0066] Based on the comparison between the monitored pressure and the safety boundaries of impact stimulation and friction stimulation, if the monitored pressure exceeds the safety boundaries of impact stimulation and friction stimulation, the explosive granulation process is in a dangerous state and an alarm is triggered immediately.

[0067] By comparing the monitored static electricity accumulation status with the safe boundary of static electricity stimulation, if the monitored static electricity accumulation status exceeds the safe boundary of static electricity stimulation, the explosive granulation process is in a dangerous state, and an alarm will be triggered immediately.

[0068] The temperature safety boundary of an explosive is the initial temperature of its thermal decomposition; the temperature safety threshold of an explosive is the critical temperature of its thermal explosion.

[0069] The initial temperature of thermal decomposition and the critical temperature of thermal explosion of the explosive sample are calculated through the following steps:

[0070] S11: Place 0.15 mg of explosive sample in the crucible of the differential scanning calorimeter, and heat it from 50 °C to 400 °C at a heating rate of 10 °C / min under a nitrogen atmosphere. Record the heat flow curve and extract the peak thermal decomposition temperature T. p ;

[0071] S12: Calculate activation energy E a :

[0072]

[0073] In the formula: It is the heating rate (K·min) -1 ); Is the rate of heating of the explosive The decomposition peak temperature at time; A is the exponential pre-factor (min) -1 ); It is the activation energy (kJ·min) -1 R is the gas constant (8.314 J·min). -1 ·K -1 );

[0074] S13: Calculate the critical temperature of thermal explosion and :

[0075]

[0076] In the formula: This is the critical temperature for thermal explosion. It is the initial temperature of thermal decomposition, and b, c, and d are constants.

[0077] Calculate the initial temperature of thermal decomposition and the critical temperature of thermal explosion of the sample. The initial temperature of thermal decomposition of the explosive is taken as the temperature safety boundary of the explosive, and the critical temperature of thermal explosion of the explosive is taken as the temperature safety threshold of the explosive.

[0078] The safety boundaries for impact stimulus and friction stimulus are obtained through the following steps:

[0079] Mechanical impact and friction with different stimuli were applied to the explosive samples. Each stimulus was repeated to obtain the scatter plot of impact stimulus-response probability and friction stimulus-response probability of the explosive samples.

[0080] Specifically, using an impact sensitivity tester, different stimulus levels were selected, and 50 tests were conducted for each stimulus level to obtain impact stimulus level-response probability data; using a friction sensitivity tester, different stimulus levels were selected, and 50 tests were conducted for each stimulus level to obtain friction stimulus level-response probability data; using an electrostatic spark sensitivity tester, different stimulus levels were selected, and 50 tests were conducted for each stimulus level to obtain electrostatic spark level-response probability data.

[0081] Nonlinear curve fitting was performed on the scatter plots of impact stimulus-response probability and friction stimulus-response probability, respectively. The stimulus values ​​corresponding to the intersection of the fitted curve and the horizontal axis were extracted as the safety boundary of the explosive under impact or friction stimulation. The stimulus value corresponding to a response probability of 2% was taken as the safety threshold of the explosive under impact or friction stimulation.

[0082] The safe boundary for electrostatic stimulation is calculated using the following steps:

[0083] Electrostatic spark stimulation was applied to the explosive sample, and repeated experiments were conducted to obtain a scatter plot of electrostatic stimulation amount-response probability of the explosive sample.

[0084] Nonlinear curve fitting was performed on the scatter plot of electrostatic stimulation-response probability, and the stimulation value corresponding to the intersection of the fitted curve and the horizontal axis was extracted as the safety boundary of the explosive under electrostatic stimulation.

[0085] Safety boundary fitting and verification

[0086] (1) Import the stimulus-response probability data into Origin software and perform nonlinear fitting using the ExpDec1 model:

[0087]

[0088] In the formula: A is the amplitude, It is the attenuation constant. This is the baseline offset.

[0089] (2) Set the confidence level to 95%, calculate the confidence interval of the fitted curve, extract the stimulus value corresponding to the intersection of the fitted curve and the horizontal axis, and use it as the safety boundary of the explosive under impact stimulation, friction stimulation or electrostatic stimulation. Use the stimulus value corresponding to the response probability of 2% as the safety threshold of the explosive under impact stimulation, friction stimulation or electrostatic stimulation.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An intelligent monitoring system for explosive safety boundaries based on multi-parameter response analysis, comprising a granulation mechanism (1), characterized in that, It also includes a sensor system, which comprises: Thermocouple sensor (5), force sensor (6) and electrostatic sensor (4); Thermocouple sensor (5), force sensor (6) and electrostatic sensor (4) are connected to signal acquisition instrument (2) and then connected to computer (3). The computer (3) enables real-time monitoring of temperature, pressure and electrostatic accumulation during the granulation process. The monitored temperature is compared with the temperature safety boundary of the explosive. If the monitored temperature exceeds the temperature safety boundary, the explosive granulation process is in a dangerous state and an alarm is triggered immediately. Based on the comparison between the monitored pressure and the safety boundaries of impact stimulation and friction stimulation, if the monitored pressure exceeds the safety boundaries of impact stimulation and friction stimulation, the explosive granulation process is in a dangerous state and an alarm is triggered immediately. Based on the comparison between the monitored static electricity accumulation trend and the safe boundary of static electricity stimulation, if the monitored static electricity accumulation trend exceeds the safe boundary of static electricity stimulation, the explosive granulation process is in a dangerous state and an alarm is triggered immediately. The safety boundaries for impact stimulation and friction stimulation are obtained through the following steps: Mechanical impact and friction with different stimuli were applied to the explosive samples. Each stimulus was repeated to obtain the scatter plot of impact stimulus-response probability and friction stimulus-response probability of the explosive samples. Nonlinear curve fitting was performed on the scatter plots of impact stimulus-response probability and friction stimulus-response probability respectively. The stimulus values ​​corresponding to the intersection of the fitted curve and the horizontal axis were extracted as the safety boundary of the explosive under impact or friction stimulation. The safety boundary for the electrostatic stimulation level is calculated through the following steps: Electrostatic spark stimulation was applied to the explosive sample, and repeated experiments were conducted to obtain a scatter plot of electrostatic stimulation amount-response probability of the explosive sample. Nonlinear curve fitting was performed on the scatter plot of electrostatic stimulation-response probability, and the stimulation value corresponding to the intersection of the fitted curve and the horizontal axis was extracted as the safety boundary of the explosive under electrostatic stimulation.

2. The intelligent monitoring system for explosive safety boundaries based on multi-parameter response analysis according to claim 1, characterized in that, The temperature safety boundary of the explosive is the initial temperature of its thermal decomposition.

3. The intelligent monitoring system for explosive safety boundaries based on multi-parameter response analysis according to claim 2, characterized in that, The initial temperature of the thermal decomposition of the explosive sample was calculated using the following steps: S11: Place the explosive sample in the crucible of the differential scanning calorimeter, record the heat flow curve, and extract the peak thermal decomposition temperature T. p ; S12: Calculate activation energy E a : In the formula: It is the heating rate; Is the rate of heating of the explosive The peak decomposition temperature at time; A is the exponential factor; It is the activation energy; R is the gas constant; S13: Calculate the initial temperature of thermal decomposition. : In the formula: This is the critical temperature for thermal explosion. It is the initial temperature of thermal decomposition, and b, c, and d are constants.

4. The intelligent monitoring system for explosive safety boundaries based on multi-parameter response analysis according to claim 3, characterized in that, The differential scanning calorimeter has a heating rate of 5-20℃ / min and a test temperature range of 50-400℃.

5. The intelligent monitoring system for explosive safety boundaries based on multi-parameter response analysis according to claim 1, characterized in that, The process of fitting the impact stimulus, friction stimulus, and electrostatic stimulus to obtain the safety boundary includes: The stimulus-response probability data were imported into Origin software and nonlinear fitting was performed using the ExpDec1 model. With a confidence level of 95%, the confidence interval of the fitted curve is calculated. The stimulus value corresponding to the intersection of the fitted curve and the horizontal axis is extracted as the safety boundary of the explosive under impact, friction or electrostatic stimulation. The stimulus value corresponding to a response probability of 2% is taken as the safety threshold of the explosive under impact, friction or electrostatic stimulation.

6. The intelligent monitoring system for explosive safety boundaries based on multi-parameter response analysis according to claim 1, characterized in that, The granulation mechanism (1) includes: Upper feed hopper (1.1); A cylindrical tube (1.2) is provided at the bottom of the upper feed hopper (1.1), and the bottom of the cylindrical tube (1.2) is provided with a screen with a replaceable aperture. Thermocouple sensor (5) is set on the side wall of cylindrical tube (1.2), and the probe is inserted into the material area above the screen through a small hole on the side wall; A force sensor (6) is installed on the screen. The lower forming funnel (1.3) is located below the cylindrical tube (1.2).

7. The intelligent monitoring system for explosive safety boundaries based on multi-parameter response analysis according to claim 6, characterized in that, The electrostatic sensor (4) is positioned to the side of the granulation mechanism (1), with the probe detection end of the electrostatic sensor (4) pointing towards the central axis of the cylindrical tube (1.2).

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