Full-automatic anti-explosion differential thermal analyzer and testing method

Abstract

The invention discloses a full-automatic anti-explosion differential thermal analyzer and a testing method, and belongs to the technical field of thermal safety performance testing of energetic materials. The instrument integrates intrinsically safe anti-explosion design, direct contact type temperature measurement and intelligent temperature control functions; a double-layer anti-explosion structure is adopted, and a buffer medium is filled between the heating cabin and the protective shell, so that explosion impact can be effectively absorbed; the peripheral heat shielding layer is provided with a water circulation channel, and efficient heat dissipation is achieved; the temperature measuring system directly contacts with a sample through a sensor, so that the response speed and precision are improved; the automatic lifting unit is linked with the control system and can quickly move away the sample and realize active explosion suppression according to a program; according to the matched method, the reaction activation energy critical temperature (Ea-Ta) of the energetic material can be accurately measured, and the thermal stability critical point is quantitatively analyzed through a dynamic temperature tracking algorithm and an Arrhenius equation extrapolation method; the device solves the problems of poor safety and low data accuracy when traditional equipment is used for testing high-risk materials, and is suitable for thermal safety evaluation of materials such as gunpowder and explosives.

Description

Technical Field

[0001] This invention relates to the field of thermal safety performance testing technology for energetic materials, and particularly to a testing instrument and method for high-precision, high-safety differential thermal analysis (DTA) of energetic materials such as gunpowder, explosives, and propellants under high-temperature and potentially explosive environments. Specifically, this invention provides a fully automated explosion-proof differential thermal analyzer and testing method that integrates intrinsically safe explosion-proof design, direct contact temperature measurement, active explosion suppression, and intelligent temperature control. Background Technology

[0002] In the research, development, quality control, and safety assessment of energetic materials (such as propellants, explosives, etc.), accurately understanding their key parameters, such as thermal decomposition characteristics, thermal stability, and critical explosion temperature, is crucial. These parameters are the core basis for assessing the potential risks of energetic materials during storage, transportation, and use, as well as for optimizing their formulation and performance. Differential thermal analysis (DTA), as an important thermal analysis method, can study the thermal behavior of materials by monitoring the temperature difference between the sample and a reference material, and is therefore widely used in the aforementioned research.

[0003] However, traditional differential thermal analyzers are not designed for testing scenarios involving highly hazardous and explosive energetic materials, and thus have the following significant drawbacks, making it difficult to meet the requirements for safe and accurate testing:

[0004] Insufficient safety design and lack of explosion resistance: Traditional instruments are typically open or conventional designs. When testing energetic materials, if the sample undergoes uncontrollable and violent decomposition or explosion during heating, the resulting instantaneous high pressure and shock wave can easily destroy core components such as the heating furnace and sensors. This not only damages the equipment but may also trigger serious secondary safety accidents, posing a significant threat to operators and the laboratory environment.

[0005] Indirect temperature measurement methods result in low data accuracy and sensitivity: Traditional differential thermal analyzers typically place the sample in a small aluminum crucible, and the temperature sensor measures the temperature at the bottom of the crucible, rather than the real-time temperature of the sample itself. This indirect measurement method suffers from thermal hysteresis and poor sensitivity, failing to accurately and quickly reflect the transient temperature changes during the rapid decomposition and exothermic process of energetic materials. This leads to deviations in key data such as the reaction initiation temperature and peak temperature, resulting in insufficient sensitivity and accuracy, and affecting the judgment of the material's critical state.

[0006] Low automation and high operational risks: During testing, especially near the material's critical point, the heat source needs to be quickly removed to stop the reaction or to cool it down. Traditional instruments rely heavily on manual operation, which is inefficient and requires operators to be in close contact with the high-risk experimental environment, posing significant personal safety risks. Furthermore, the poor consistency of manual operation can introduce human error, affecting the repeatability of experimental results.

[0007] Lack of rapid suppression mechanisms for violent reactions: For energetic material testing, not only is passive protection required "after the fact," but also rapid active explosion suppression capabilities "during the event" when abnormal exothermic signals are detected. Traditional instruments lack the rapid response capabilities of automatic lifting units and temperature sensors, making it impossible to quickly determine when the sample has started to react or to automatically and quickly remove the sample from the high-temperature zone, thus failing to effectively suppress potential explosions.

[0008] The aforementioned technical bottlenecks severely restrict the reliable application of differential thermal analysis (DTA) technology in the high-risk field of energetic materials. Therefore, there is an urgent need to develop a DTA instrument that integrates intrinsically safe explosion-proof design, direct-contact high-sensitivity temperature measurement, and fully automated intelligent control to achieve safe and accurate testing of the thermal safety performance of energetic materials. Summary of the Invention

[0009] To address the above problems, this invention provides a fully automated explosion-proof differential thermal analyzer and testing method, which can solve the problems of low accuracy of test data and dangerous operation process of traditional methods, and can also obtain the critical temperature of reaction activation energy measurement data.

[0010] Specifically, the fully automatic explosion-proof differential thermal analyzer includes a heating module body (1), a positioning element (2), a sensor fixing module (3), an automatic lifting unit (4), and a control center (5). In particular, the heating module body (1) mainly includes a protective shell (1-1), a heating element (1-2), a buffered heat transfer medium (1-3), a heat shield layer (1-4), a detachable top cover (1-5), and a heating chamber (1-6).

[0011] The main body (1) of the heating module has a double-layer explosion-proof structure, which is achieved by a protective shell (1-1) and an internal replaceable heating chamber (1-6). The cavity between the heating chamber (1-6) and the heating element (1-2) is filled with an explosion-buffered heat transfer medium (1-3).

[0012] The buffered heat transfer medium (1-3) uses granular magnesium oxide as the core buffer medium, with a filling density of 65% to 95%, and the maximum temperature resistance of magnesium oxide is 1700°C. It has the following functions: ① It achieves efficient heat conduction through high thermal conductivity during normal heating; ② Under explosion conditions, it absorbs shock wave energy through friction and displacement between particles, while suppressing abrupt changes in the heat conduction path, thereby protecting the circuits and other key components inside the heating element.

[0013] The heating cabin (1-6) is integrally processed from high-strength, high-thermal-conductivity metal material and is rigidly connected to the heating module body (1) through two screw holes and stainless steel positioning elements (2). The heating cabin (1-6) has an explosion-proof performance of up to 50mg TNT equivalent. When the explosion energy exceeds the explosion-proof range, it is absorbed by the plastic deformation of the heating cabin (1-6) and further absorbed by the buffer heat transfer medium (1-3), thus protecting the heating module body (1) and other structures to achieve the explosion-proof effect.

[0014] The heat shield layer (1-4) is located around the heating element (1-2) and is 30-50mm away from the heating element (1-2). It is a double-layer hollow cylindrical structure with an axially extending annular water circulation channel inside. Its cylindrical wall is provided with an inlet (1-4a) and an outlet (1-4b) that are connected to the channel. The circulating water absorbs and consumes the heat and heat radiation generated by the heating module.

[0015] The features are as follows: ① When the heating module body (1) operates at a high temperature of 400~500℃, the heat shield layer (1-4) absorbs the heat conducted and radiated by the heating element (1-2) through forced convection heat exchange (flow rate 1-2m / s) in the annular water circulation channel, and removes the heat from the system through the circulating water, so as to ensure that the operating temperature of the peripheral equipment (including the host, circuit and other components) is stable in the safe temperature range (≤40℃).

[0016] ②The heat shield layer (1-4) integrates a pressure sensor and a flow switch to form a dual closed-loop monitoring module for the water circulation system. When the water pressure is detected to be lower than the set threshold or the flow is abnormal, the system triggers the heating power cut-off protocol with a response time of <100ms to avoid the risk of insulation failure or thermal damage to components caused by thermal runaway.

[0017] ③Based on the ultra-high specific heat capacity of water (4.18 kJ / kg·K) and forced convection heat transfer characteristics, the heat shield layer (1-4) can achieve gradient cooling after a single experiment: the high temperature stage (500℃→200℃, ΔT=300℃) is completed within 20 minutes through active water cooling, with a cooling efficiency 36 times higher than that of natural cooling; the low temperature stage (200℃→80℃) requires about 60 minutes due to the thermodynamic nonlinear characteristics, ensuring that the system quickly resets to a repeatable experimental state;

[0018] ④ The heat shield layer (1-4) constructs a bidirectional thermal resistance network of "heating-cooling" through the coordinated control of dynamically adjusting the heat flux density of the water circulation and the pulse heating compensation of the heating module. Specifically, during steady-state heating, the constant water flow rate stabilizes the heat absorption rate, providing a temperature field uniformity of ±0.1℃; when the temperature exceeds the target set value (e.g., 500℃), the system absorbs the excess heat by transiently increasing the heat flux density, and combined with heating compensation adjustment, the temperature converges to the set point (500±0.1℃) within 30 seconds, improving the temperature control accuracy and efficiency by 5 times compared to traditional solutions.

[0019] The detachable end cap (1-5) is located on the top of the heating module body (1) and forms a separable and tight connection with the protective shell (1-1). When the heating cabin (1-6) deforms due to an explosion, the user can pull out the positioning element (2) and the heating cabin (1-6) as a whole through the detachable end cap (1-5), and then remove the fastening bolts (1-6a) between the two to directly replace the damaged heating cabin (1-6). This design uses the heating cabin (1-6) as a consumable part with directional deformation. While maintaining the integrity of the overall module structure, it achieves high-efficiency explosion resistance through local controllable deformation and modular quick replacement, and has the advantages of compact structure and low maintenance cost.

[0020] The positioning element (2) is positioned above the heating chamber (1-6) to guide the sample tube (3-1) into the heating chamber (1-6) accurately. Its structural feature is that the positioning element (2) adopts a tapered flared guide structure with a wider inlet diameter (usually more than 5mm larger than the outer diameter of the test tube) to compensate for the vertical positioning deviation (±1.5mm) of the glass test tube. When the test tube moves downwards, its irregular end face or skew angle is gradually corrected by the flared structure, eventually guiding it to the coaxial positioning hole. The diameter of the coaxial positioning hole is 0.1-0.2mm larger than the outer diameter of the test tube, ensuring a uniform gap between the test tube and the inner wall of the heating chamber (1-6), thereby eliminating uneven local heating and controlling the temperature gradient.

[0021] The positioning element (2) and the heating chamber (1-6) are rigidly connected by a tight fit. When the sample explodes, the impact energy is absorbed by the plastic deformation of the heating chamber (1-6) first, while the positioning element (2) maintains the structural integrity to maintain the positioning accuracy.

[0022] The heating module body (1) is equipped with a quick-release structure on the top. By removing the fastening bolts of the top cover (1-5), the deformed heating cabin (1-6) and the positioning element (2) can be extracted as an integrated module, thereby improving maintenance efficiency.

[0023] The bottom surface of the positioning element (2) has a constricted opening, which forms a gap of 0.1-0.2 mm between itself and the sample tube (3-1), constituting a near-contact thermal coupling interface, so that the heating zone (bottom) and the conduction zone (top) reach a quasi-isothermal state; the constricted section is equivalent to a dynamic thermal barrier layer, and based on the high thermal conductivity of metal, it forms a temperature-locking ring structure, which significantly reduces axial heat loss; experimental verification shows that this structure can suppress environmental heat exchange to near adiabatic calorimetry conditions.

[0024] The sensor fixing module (3) achieves direct measurement and high sensitivity through the following design:

[0025] ① Traditional differential thermal analyzers, due to their structural design, place the sample in a crucible and indirectly obtain the sample reaction temperature data by measuring the temperature at the bottom of the crucible. This method suffers from poor sensitivity and slow response. Based on the structural design flaws of traditional differential thermal analyzers, the overall structure of the explosion-proof differential thermal analyzer has been redesigned. This redesign allows two temperature sensors (3-2) to directly contact the sample and reference respectively, enabling direct real-time acquisition of the sample reaction temperature and significantly improving response sensitivity.

[0026] ② For high-viscosity or high-temperature sintered samples, a capillary glass tube can be fitted onto the surface of the temperature sensor (3-2), which can significantly improve the service life of the sensor;

[0027] ③ The sensor fixing component (3-4) is made of non-metallic low thermal conductivity material. It fixes the temperature sensor (3-2) through coaxial positioning holes and set screws. When the sample explodes, the sensor fixing component (3-4) maintains the contact state between the temperature sensor (3-2) and the sample through rigid connection, and is not affected by the sample explosion vibration, so as to ensure continuous output of temperature curve.

[0028] ④ The sensor fixture (3-4) is equipped with a locking knob on top. The sensor assembly can be unlocked and removed as a whole by operating the knob, so as to quickly replace the sensor or clean the sample and improve the efficiency of the test.

[0029] To further explain, the perforated sample cap (3-3) fits tightly against the sample tube opening when installed, isolating external airflow to reduce heat exchange while allowing the sample cap to be lifted by an explosion impact for pressure relief. The sensor holder (3-4) secures the temperature sensor (3-2) with set screws on both sides, resisting the lifting force during pressure relief to maintain direct contact between the sensor and the sample without separation. This module, through its structural co-design, achieves high-precision temperature measurement while ensuring explosion-proof safety and simplifying the operation process.

[0030] The automatic lifting unit (4) is equipped with an interface for communication with the operating software. The operating software can remotely send control commands to the interface module, thereby realizing remote control of the automatic lifting unit (4). During the experiment, the automatic lifting unit (4) can lift the sample according to the preset program or the received control command to perform rapid cooling operation on the sample, and at the same time, it can achieve the explosion suppression function by quickly moving the sample away from the heat source.

[0031] The control center (5) can perform rapid cooling and explosion-proof monitoring according to preset programs or instructions, and can realize data recording and analysis functions with the operation software, supporting real-time recording and subsequent analysis of the test process.

[0032] The control center (5) can operate the lifting unit to lift the sample tube out of the heating module to achieve rapid cooling. Within 60 seconds, the temperature of the test sample can be reduced from 450℃ to below 100℃, enabling rapid sample replacement without stopping heating and further improving experimental efficiency. No personnel need to operate at close range during lifting, ensuring experimental safety.

[0033] This instrument can test the critical activation energy-critical temperature (Ea-Ta) of a sample, and combined with dynamic thermal analysis technology, achieves high-precision characterization of the sample's thermal behavior. The specific operating procedure is as follows:

[0034] ① Thermodynamic parameter setting: The linear heating program of heating rate (β) and target temperature (T_f) can be set, and the isothermal holding time (t_hold) can be set. The instrument will automatically execute the heating protocol and trigger the experimental preparation signal.

[0035] ② Sample loading and data acquisition: When the internal temperature of the heating module body (1) reaches the preset value, the sample is placed in the constant temperature field through the automatic lifting unit (4), and the built-in dynamic equivalent temperature tracking (DET) algorithm is started simultaneously. The sensor (4-1) samples at high speed and combines moving average filtering and least squares optimization to calculate the minimum variance of the temperature-time curve in real time, eliminating thermal hysteresis and signal noise interference.

[0036] ③ Thermal Phenomenon Analysis: The exothermic peak characteristics were monitored by real-time temperature curves to identify the reaction initiation point. After multiple iterative experiments, the temperature range with the weakest exothermic enthalpy change (ΔH→0) was selected, indicating that the reaction driving force is approaching the activation energy threshold.

[0037] ④ Precise location of critical temperature: Based on multi-range test results, a detailed experiment with a temperature gradient of 1-2℃ was designed. The activation energy abrupt change point, i.e., the critical temperature T_c, was determined by extrapolation of the Arrhenius equation. This parameter characterizes the boundary condition for the material to transition from a steady state to a self-accelerating reaction.

[0038] The fully automated explosion-proof differential thermal analyzer and testing method provided by this invention significantly improves the safety of the heating test process, the accuracy of data results, and the convenience of the experiment through structural innovation and intelligent control design of traditional instruments, bringing the following beneficial effects:

[0039] 1) High-precision explosion-proof temperature measurement and enhanced safety

[0040] The sensor fixing module directly contacts the sample through dual temperature sensors, eliminating interference from intermediate media and improving response sensitivity by 200%.

[0041] The perforated sample cap and the non-metallic, low thermal conductivity fixing component are designed together to form a pressure relief channel when the pressure is released, while the rigid connection maintains the sensor contact state and ensures the continuity of the temperature curve under explosion conditions.

[0042] 2) Intelligent temperature control and high-efficiency heat dissipation system

[0043] The heat shield layer integrates forced water cooling (flow rate 1-2m / s) and dual closed-loop monitoring to achieve gradient cooling in the high-temperature zone (500℃→200℃) within 20 minutes, with a cooling efficiency 36 times higher than natural cooling.

[0044] With dynamic adjustment of heat flux density and pulse heating compensation working together, the temperature stability under constant temperature can reach ±0.05℃, and the temperature of the external equipment is stable within the safe temperature range (≤40℃).

[0045] 3) Modular explosion-proof and rapid maintenance design

[0046] The heating module adopts a double-layer explosion-proof structure (protective shell + replaceable heating cabin), and the buffer cavity is filled with magnesium oxide particles (temperature resistant to 1700℃). In the event of an explosion, it absorbs the impact energy through plastic deformation and pressure relief field.

[0047] The detachable top cover and quick-release structure allow for the complete replacement of damaged modules, improving maintenance efficiency and reducing overall maintenance costs.

[0048] 4) Precise determination of the critical temperature of activation energy in isothermal mode

[0049] The reaction is quickly interrupted by an automatic lifting unit (sample is lifted away from the heat source for cooling), and the dynamic equivalent temperature tracking (DET) algorithm in isothermal mode is used to accurately locate the activation energy critical temperature.

[0050] Based on temperature gradient experimental data, the activation energy mutation point is determined by thermal analysis algorithm, and the critical temperature T_c is determined by extrapolation method, providing a reliable thermodynamic threshold for safe industrial production and avoiding the risk of self-accelerating reaction. Attached Figure Description

[0051] Figure 1 This is the front view of the present invention;

[0052] Figure 2 This is a cross-sectional view of the main body (1) of the heating module in this invention;

[0053] Figure 3 This is a detailed view of the sensor fixing module (3) in this invention.

[0054] The components are: 1. Heating module body, 1-1. Protective shell, 1-2. Heating element, 1-3. Buffered heat transfer medium, 1-4. Heat shield layer, 1-4a. Water inlet, 1-4b. Water outlet, 1-5. Removable end cap, 1-6. Heating chamber, 1-6a. Fastening bolt, 2. Positioning element, 3. Sensor fixing module, 3-1. Sample tube, 3-2. Temperature sensor, 3-3. Sample cover with hole, 3-4. Sensor fixing component, 4. Automatic lifting unit, 5. Control center. Detailed Implementation

[0055] This embodiment achieves high-precision characterization of the thermal behavior of samples by determining the critical temperature of the activation energy of the reaction under isothermal mode, combined with dynamic thermal analysis technology. The specific process is as follows:

[0056] Example 1: Thermodynamic parameter setting and system initialization

[0057] This embodiment uses an explosion-proof differential thermal analyzer to determine the activation energy critical temperature. The specific steps are as follows:

[0058] ①Program input: Set the linear heating program parameters through the operating software, including heating rate β, target temperature T_f, and constant temperature holding time t_hold;

[0059] ② Equipment self-test: The heating module starts the preheating protocol. After the temperature stabilizes, the experiment preparation signal is triggered, and the servo motor of the automatic lifting unit completes the initial position calibration.

[0060] ③ Safety Lockout: The water pressure sensor monitors the cooling water pressure in real time, and automatically triggers the emergency stop protocol when an abnormal pressure change is detected.

[0061] Example 2: Dynamic Thermal Analysis Process

[0062] ① Sample loading: When the furnace temperature stabilizes at T_f, the automatic lifting unit will vertically lower the sample tube to the center of the constant temperature field;

[0063] ② Data acquisition: The dynamic equivalent temperature tracking (DET) algorithm is started synchronously. The high-speed data from the temperature sensor (3-2) is processed by moving average filtering and least squares optimization to calculate the temperature-time curve in real time.

[0064] ③ Exothermic feature identification: When σ²(t) exceeds 3 times the standard deviation of the baseline noise, an event marker is triggered, and the characteristic parameters of the exothermic peak are extracted by the differential algorithm: peak temperature, peak area and peak width.

[0065] Example 3: Critical Temperature Determination Method

[0066] ① Range screening: A temperature-reaction intensity matrix was established through a stepped cooling experiment to screen the temperature range that satisfies ΔH→0 (ΔH<0.1J / g);

[0067] ② Precise positioning: Set up a detailed experiment within the target temperature range (e.g., 230-250℃) and use the Arrhenius equation extrapolation method:

[0068] ③ Verification experiment: After cooling the aforementioned sample to room temperature, reload it and repeat the experiment using heating mode to verify whether an exothermic peak exists.

[0069] Example 4: Industrial Application Verification

[0070] A test was conducted on a certain organic peroxide:

[0071] Initial tests showed that at 240℃, ΔH→0 (ΔH=0.08J / g);

[0072] Detailed experiments determined that Ta = 237℃ (Ea = 185kJ / mol);

[0073] Industrial field verification shows that when the process temperature is controlled at 238℃, production energy consumption is significantly reduced and the generation of by-products is effectively suppressed, and the final product production efficiency is increased by 30%.

Claims

1. A fully automatic anti-blast differential thermal analyzer and test method, characterized by, The full-automatic anti-explosion differential thermal analyzer comprises a heating module main body (1), a positioning element (2), a sensor fixing module (3), an automatic lifting unit (4) and a control center (5); The heating module main body (1) adopts a double-layer anti-explosion structure and the top cover (1-5) is detachable; The positioning element (2) is located above the heating module main body (1), and the inlet end diameter is slightly larger than the outer diameter of the sample tube (3-1); The sensor fixing module (3) is used for fixing the sample tube (3-1) and the temperature sensor (3-2), so as to prevent the sensor from being separated due to sample reaction heat shock; The control center (5) is internally provided with operation software, which can control the automatic lifting of the automatic lifting unit (4) and can set the constant temperature mode parameters of the control center (5) to automatically execute the temperature rising-constant temperature-temperature lowering test process.

2. The fully automated bomb calorimeter and test method according to claim 1, wherein, The heating module main body (1) mainly comprises a protective shell (1-1), a heating element (1-2), a buffer type heat transfer medium (1-3), a heat shielding layer (1-4), a detachable top cover (1-5) and a heating seat cabin (1-6); The buffer cavity between the heating element (1-2) and the heating seat cabin (1-6) is filled with a buffer material (1-3); in particular, the buffer material (1-3) uses magnesium oxide particles as a core filling medium, and the filling density is 65%-95%, which has impact resistance and thermal stability, and protects the internal components from accidental damage.

3. The fully automated bomb calorimeter and test method according to claim 2, wherein, The heat shielding layer (1-4) is located outside the heating element (1-2) and has a double-layer hollow cylindrical structure, and an annular water circulation channel extending along the axial direction is formed in the inside, and the cylinder wall is provided with a water inlet (1-4a) and a water outlet (1-4b) communicated with the channel, which absorbs and discharges the additional heat and heat radiation generated by the heating module through circulating water; In particular, the heat shielding layer (1-4) internally integrates a pressure sensor and a circulating water flow switch to form a double closed-loop control system, and the pressure sensor, the flow switch and the temperature sensor are data-linked to adjust the water flow rate to realize rapid cooling.

4. The fully automated bomb calorimeter and test method of claim 1, wherein: The positioning element (2) adopts a horn mouth design to ensure the positioning accuracy of the sample tube; the positioning element (2) is connected with the heating seat cabin (1-6) of the heating module main body (1), and when the heating seat cabin (1-6) is deformed, the deformed assembly and the positioning element (2) can be integrally pulled out by detaching the fastening bolts (1-6a).

5. The fully automated bomb calorimeter and test method of claim 1, wherein: The sensor fixing module (3) sets the sample to be tested and the temperature sensor (3-2) in direct contact to eliminate the thermal resistance of the intermediate medium and ensure the directness and high sensitivity of the thermal measurement signal. The sensor fixing module (3) further comprises a sample cover with holes (3-3) and a sensor fixing part (3-4). The sample cover with holes (3-3) is used to isolate the external environment temperature and air convection from the interference on the sample temperature, and at the same time prevent the heat generated by the reaction from being dissipated from the sample tube opening, so as to ensure the accuracy of the test result. When the sample reacts violently or explodes, the sample cover can be lifted by high pressure to play a role in timely pressure relief. The sample cover is made of a non-metallic material with poor thermal conductivity such as Teflon, which can maximize the prevention of heat dissipation from the surface of the sample cover.

6. The fully automated ballistic differential thermal analyzer and method of testing of claim 5, wherein, The sensor fixing piece (3-4) is made of non-metal low-thermal-conductivity material, and is stably connected with the temperature sensor (3-2) through a top screw; when the sample unloads and lifts the sample cover (3-3), the sensor fixing piece (3-4) maintains the close contact between the temperature sensor (3-2) and the sample, and ensures the continuous output of accurate temperature curve.

7. A test method of a fully automatic anti-blast differential thermal analyzer, characterized in that, The instrument can test the critical temperature of reaction activation energy (Ea-Ta), combine dynamic thermal analysis technology, and realize high-precision characterization of the thermal behavior of the sample. The specific operation process is as follows: ①Thermodynamic parameter setting: the constant heating rate (β) and the linear temperature rising program of the target temperature (T_f) can be set, the constant temperature holding time (t_hold) is set, the instrument automatically executes the heating protocol and triggers the experimental preparation signal. ②Sample loading and data acquisition: when the internal temperature of the heating module main body (1) reaches the preset value, the sample is placed in the constant temperature field through the automatic lifting unit (4), and the built-in dynamic equivalent temperature tracking (DET) algorithm is started synchronously. The temperature sensor (3-2) samples at high frequency, combines sliding window multi-point smoothing and least square optimization, and calculates the variance minimum value of the temperature-time curve in real time, eliminating thermal hysteresis and signal noise interference. ③Thermal phenomenon analysis: the exothermic peak characteristics are monitored through the real-time temperature curve, and the reaction starting point is identified. After multiple iterative experiments, the temperature range with the weakest exothermic enthalpy change (ΔH→0) is selected, indicating that the reaction driving force tends to the activation energy threshold. ④Critical temperature accurate positioning: based on the rough measurement result, a fine experiment with small temperature gradient is designed, and based on the temperature gradient experimental data, the activation energy mutation point, i.e. the critical temperature T_c, is determined through the thermal analysis algorithm. This parameter represents the boundary condition of the transition of the material from steady state to self-accelerating reaction.

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