A method for calibrating the performance of an accelerated calorimeter based on the resistance joule heating effect

Abstract

The application discloses a kind of based on resistance block joule heat effect's accelerating calorimeter heat release detection performance calibration method.The application provides constant electric power of resistance block in accelerating calorimeter by constant current source in calibration experiment mode, then according to heat balance formula, the heat loss caused by the inconsistency of accelerating calorimeter furnace cover, furnace wall, furnace bottom and sample thermocouple temperature measurement is calculated, and a compensation temperature relative to the whole is solved.According to the compensation temperature obtained, the temperature of furnace cover, furnace wall and furnace bottom is corrected by the compensation temperature when the system reaches steady state equilibrium, and the purpose of calibration is finally achieved.The application can solve the problem of inconsistent thermocouple temperature measurement of sample thermocouple relative to furnace cover, furnace wall and furnace bottom during the detection of accelerating calorimeter.The application has strong applicability, is innovative, and has important significance for calibrating the heat release detection performance of accelerating calorimeter and improving the accuracy of chemical reaction heat hazard evaluation.

Description

Technical Field

[0001] This invention relates to a method for calibrating the performance of an accelerated calorimeter based on the resistance Joule heating effect. Background Technology

[0002] In the fine chemical industry, the safety of chemical production is a crucial issue that cannot be ignored. In particular, insufficient understanding of the thermal hazards of chemical substances can lead to thermal runaway in chemical processes, resulting in unimaginable consequences. Accelerated calorimetry is one of the important tools for analyzing the causes of thermal safety accidents.

[0003] Typically, accelerating calorimeters operate in a heating-wait-search (HWS) mode. [1] The process begins by heating the sample to a preset temperature and allowing it to reach thermal equilibrium with the insulated furnace. Then, it detects whether the sample releases heat. If no heat is released, the sample is heated to the next temperature point, initiating a new cycle of "heating-waiting-searching." During the search phase, the sample's temperature rise rate is monitored in real-time to detect a reaction if it exceeds a set detection threshold. If the rate exceeds the threshold, a reaction is detected, and the process proceeds to the tracking phase. Thermodynamic and thermodynamic analyses of the temperature-time series data from this tracking phase are then performed to predict the thermal hazard of the chemical substance.

[0004] Accelerated calorimeters (ACC) typically operate in environments involving strong acids, strong alkalis, and high temperatures. After prolonged operation, significant drift often occurs in the thermocouples on the sample, furnace lid, walls, and bottom. This inconsistency between thermocouples not only affects the accuracy of temperature rise rate detection during the waiting and search phases but also impacts performance during the adiabatic tracking phase. As a crucial analytical instrument for the causes of thermal safety accidents, a deterioration in the insulation performance of the ACC can lead to errors in the measurement of parameters characterizing thermal hazards, such as adiabatic temperature rise and thermal decomposition kinetics, resulting in inaccurate assessments of chemical process hazard levels with potentially disastrous consequences.

[0005] In patent ZL 201910297550.7, "A Method for Evaluating the Adiabatic Performance of an Accelerated Calorimeter Based on the Joule Thermal Effect", [2] This invention proposes an evaluation method for the adiabatic tracking performance of an accelerated calorimeter. The dynamic adiabatic performance factor obtained by this invention comprehensively reflects the influence of factors such as the heat absorbed by the sample cell and the temperature tracking effect of the furnace on the sample's adiabatic performance. By setting different DTBP-toluene solution concentrations, different heat release rates are generated, thereby realizing the evaluation of the adiabatic performance of the accelerated calorimeter under different operating conditions. However, it neglects the calibration of the heat release detection performance (waiting and searching phase) when the accelerated calorimeter is in the thermal equilibrium stage, that is, it does not propose a reasonable solution to the drift problem of the thermocouple inside the accelerated calorimeter.

[0006] In view of the problem of thermocouple drift, in the current metrological technology industry field, the thermocouple calibration is usually to bundle the secondary standard platinum rhodium 10-platinum thermocouple and the calibrated thermocouple together, and put them into the tube furnace qualified temperature field to complete by comparison method. The consistency of the tube furnace temperature field is an important factor to ensure the accuracy of the calibration result. In JJF1637-2017 "Calibration Specification for Low Metal Thermocouples" [3] and JJF1262-2010 "Calibration Specification for Sheathed Thermocouples" [4] , the axial temperature field and the radial temperature field of the tube furnace are clearly required. However, after long-term use, the thermocouple and the furnace body are sintered and cannot be disassembled. Therefore, this traditional calibration method is not suitable for the in-situ calibration of the consistency of the thermocouple of the accelerated calorimeter. If an effective technology can be proposed to eliminate the influence of the non-consistency between the sample thermocouple and the furnace cover, furnace wall and furnace bottom thermocouple, it has great significance for the guarantee of the detection performance index of the accelerated calorimeter.

[0007] REFERENCES

[0008] [1] Wang JC. Evaluation and improvement method of adiabatic performance of accelerated calorimeter [D]. China Jiliang University, 2019.

[0009] [2] Wang XN, Zhang JH, Wang JC, Yang SJ, Ye SL. An evaluation method for the adiabatic performance of an accelerated calorimeter based on the Joule effect [P]. Zhejiang Province: CN109945994B, 2021-03-02;

[0010] [3] Hou SL, Wang H, Gao FS, Xu XF. Interpretation of JJF1637-2017 "Calibration Specification for Low Metal Thermocouples" [J]. China Measurement, 2018(05): 129-130;

[0011] [4] Hou SL, Wang H. Interpretation of JJF1262-2010 "Calibration Specification for Sheathed Thermocouples" [J]. China Measurement, 2011(08): 131-132. SUMMARY

[0012] In view of the deficiencies of the prior art, the present application starts from the perspective of resistance block Joule heat effect and thermal balance. Under the condition of thermal balance of the accelerated calorimeter, according to the principle that the heat power of the resistance block is equal to the heat loss, a method for realizing the calibration of the detection performance of the accelerated calorimeter based on the Joule heat effect of the resistance block is proposed, i.e. the consistency calibration of the temperature measurement of the sample thermocouple and the furnace cover, furnace wall and furnace bottom thermocouple is realized, the error caused by the non-consistency between the thermocouples is eliminated, the sample temperature and the overall temperature of the accelerated calorimeter have good consistency, and the detection performance of the calibrated instrument is realized.

[0013] The technical problem of the present application can be solved by the following technical scheme:

[0014] A method for calibrating the performance of an accelerating calorimeter based on the resistance Joule heat effect, in particular:

[0015] A constant current source is used to provide two different electric powers to the resistance block placed in the accelerating calorimeter, and the mathematical expression of the electric power is derived according to the heat balance formula;

[0016] The heat loss Q caused by the temperature inconsistency of the thermocouples at the resistance block, the furnace cover, the furnace wall and the furnace bottom is calculated, and the compensation temperature ΔT(T) of the furnace cover, the furnace wall and the furnace bottom of the accelerating calorimeter is solved;

[0017] According to the obtained ΔT(T), the temperature measured by the thermocouples of the furnace cover, the furnace wall and the furnace bottom is corrected by adding ΔT(T) when the system reaches a steady state balance at each temperature control point.

[0018] The beneficial effects of the present application are:

[0019] The resistance block is designed to be placed in the accelerating calorimeter for experiment, when calibrating a certain temperature control point, two different electric powers P are provided by the constant current source, the temperature deviation of each part of the accelerating calorimeter relative to the sample is studied after the system reaches a steady state heat balance, and the furnace cover, the furnace wall and the furnace bottom of the accelerating calorimeter are compensated as a whole, and a ΔT(T) is added to the temperature value measured by the thermocouples at each part of the furnace body to compensate for the heat loss.

[0020] The present application compensates for the heat loss caused by the temperature inconsistency between the thermocouples, calibrates the temperature consistency function of the sample thermocouple and the furnace cover, the furnace wall and the furnace bottom thermocouple, and further improves the temperature consistency between the thermocouples. In the calibration mode described in the present application, corresponding experimental operations are performed at each temperature control point, and each temperature control point is calibrated accordingly, so that the problem of temperature inconsistency between the sample thermocouple and the furnace cover, the furnace wall and the furnace bottom thermocouple caused by long-term drift is solved, so that the detection performance of the accelerating calorimeter is calibrated and improved. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 Resistance block for calibrating the detection performance of the accelerating calorimeter;

[0022] Figure 2 Connection diagram of the experimental platform for calibrating the detection performance of the accelerating calorimeter;

[0023] Figure 3 Principle diagram of the calibration mode for calibrating the detection performance of the accelerating calorimeter;

[0024] Figure 4 Four-wire connection method circuit diagram of the resistance block;

[0025] Figure 5 A calibration experiment operation flow chart for calibrating the detection performance of an accelerated calorimeter. DETAILED DESCRIPTION

[0026] A method for calibrating the detection performance of an accelerated calorimeter based on the Joule heat effect of a resistance block, which uses the Joule heat effect of a resistance block to generate heat and calibrate the exothermic detection performance based on the Joule heat effect of the resistance block and a heat balance equation. Specifically, the method comprises the following steps:

[0027] In view of the applicability of the traditional calibration method and the difficulty of thermocouple calibration, the present application proposes to replace the sample with a customized resistance block to calibrate the accelerated calorimeter. The specific structure of the resistance block is shown in the accompanying Figure 1 The resistance block is fixed in the inner cavity of the accelerated calorimeter by high-temperature-resistant ropes. The temperature on the surface of the resistance block is measured by the original sample thermocouple. The resistance block thermocouple is pasted on the surface of the resistance block with high-temperature-resistant adhesive tape. It is necessary to exhaust the air on the surface to avoid affecting the temperature measurement accuracy of the thermocouple and introducing other errors.

[0028] The preparation work before the calibration experiment is to determine the temperature control temperature points and the temperature rise step, so that the accelerated calorimeter can heat and control the corresponding temperature points. A constant current source is used to power the resistance block while the accelerated calorimeter is working. When the constant current source provides a constant power P1 to the resistance block, the temperature on the surface of the resistance block will eventually reach a state of thermal equilibrium with the temperature of the furnace body, but at this time there is a temperature difference between the sample temperature and the furnace body temperature. The accelerated calorimeter records the temperature of each part in the furnace in real time through the temperature measurement software, and the real-time temperature of the sample, furnace cover, furnace wall and furnace bottom can be used to calculate the temperature difference. After the resistance block reaches thermal equilibrium for a period of time, a different constant power P2 is provided, and when the temperature on the surface of the resistance block again reaches thermal equilibrium, the temperature difference between the sample temperature and the furnace body temperature will be further reduced, but the error caused by the non-uniformity of the thermocouple temperature measurement still exists. Through the supply of two different constant electric powers, the heat loss caused by the non-uniformity of the thermocouple temperature measurement can be calculated, and the compensation temperature AT(T) can be solved, and the temperature of the furnace cover, furnace wall and furnace bottom as a whole can be calibrated. At each temperature point, the resistance block is provided with two different constant electric powers, so that each step temperature control temperature point can be calibrated. The calibration principle diagram is shown in the accompanying Figure 3 The calibration mode can compensate for the non-uniform heat loss between the sample thermocouple and the furnace cover, furnace wall and furnace bottom thermocouples, and further improve the consistency of the sample, furnace cover, furnace wall and furnace bottom temperatures under constant temperature control. The exothermic detection performance of the accelerated calorimeter is calibrated. According to the operation method of the calibration experiment, the specific formula derivation is as follows:

[0029] According to the heat balance equation: Q吸 = Q 放 When the resistance block reaches thermal equilibrium with the furnace body, the given heat power P is also equal to the heat dissipated, which is relative to the furnace cover, furnace wall and furnace bottom. Its mathematical expression is:

[0030] P = h1(T R -T T ) + h2(T R -T W ) + h3(T R -T B )

[0031] Where: h1, h2, h3 are the equivalent heat transfer coefficients of the furnace cover, furnace wall and furnace bottom, respectively, which are related to the material itself, heat transfer area and heat transfer form; T R , T T , T W , T B are the temperature values measured by the thermocouples of the sample (replaced by the resistance block in the experiment), the furnace cover, the furnace wall and the furnace bottom, respectively. The temperature difference of each part in the accelerated calorimeter will also be different at different step temperature points T, that is, the values of the above expressions T R -T T , T R -T W , T R -T B are also different, or they are functions of the internal temperature T of the accelerated calorimeter.

[0032] When thermal equilibrium is reached, the resistance block provides a power P, at which time the resistance block temperature and the furnace cover, furnace wall and furnace bottom temperature, that is, the target control temperature, exist a temperature difference, which is denoted as a. Then, different power is provided to the resistance block, and the corresponding a value will also be different, and the deviation caused by the inconsistency of the thermocouple temperature measurement still exists. Then, for different heat power, the expression of the resistance block after reaching thermal equilibrium is:

[0033] P1 = h1(a1 + X(t)) + h2(a1 + Y(t)) + h3(a1 + Z(t))

[0034] P2 = h1(a2 + X(t)) + h2(a2 + Y(t)) + h3(a2 + Z(t))

[0035] Wherein: a1, a2 are the temperature difference of the resistance block under the given different electric power and the temperature of the furnace cover, furnace wall and furnace bottom in the steady state equilibrium state, the temperature values of the furnace cover, furnace wall and furnace bottom in the steady state equilibrium state are equal; X(t) is the deviation of the sample thermocouple and the furnace cover thermocouple in temperature measurement, which is related to the internal temperature of the accelerated calorimeter; Y(t) is the deviation of the sample thermocouple and the furnace wall thermocouple in temperature measurement, which is related to the internal temperature of the accelerated calorimeter; Z(t) is the deviation of the sample thermocouple and the furnace bottom thermocouple in temperature measurement, which is related to the internal temperature of the accelerated calorimeter.

[0036] The above two expressions are further simplified as:

[0037]

[0038] The meaning of the expression h1(t)+h2(t)+h3(t) on the left side of the above formula is the heat loss caused by the temperature measurement inconsistency of the sample thermocouple and the furnace cover, furnace wall and furnace bottom thermocouples.

[0039] Let Q=h1(t)+h2(t)+h3(t), to compensate for the heat loss caused by the temperature measurement inconsistency between the thermocouples, a compensation temperature value ΔT(T) can be added to the temperature measured by the furnace cover, furnace wall and furnace bottom thermocouples for temperature control, and the solution of ΔT(T) is as follows:

[0040] Let Q=(h1+h2+h3)ΔT(T), and solve the above and below formulas:

[0041]

[0042] Further simplification gives:

[0043] Wherein a1, a2 is a temperature value, which is related to the size of the given power and the internal temperature of the accelerated calorimeter, so ΔT(T) is also a variable related to the internal temperature of the accelerated calorimeter.

[0044] The above calibration operation is performed on different step temperature points of the experimental setup, and the obtained ΔT(T) value is used to perform polynomial fitting on ΔT. When the accelerated calorimeter is in thermal equilibrium, the step temperature points are used as the independent variable T, and ΔT(T) is used as the corresponding dependent variable. At each step temperature point, the corresponding ΔT(T) can be obtained through polynomial fitting formula, and the polynomial fitting effect can be evaluated by means of residual error. The mathematical expression form of polynomial fitting is:

[0045] ΔT(T)=aT n +bT n-1 +…+cT+d

[0046] a, b, c, d are coefficients corresponding to the polynomial, T is the step temperature value, the invention needs to calibrate the consistency of the furnace cover, furnace wall, furnace bottom thermocouple as a whole, so in the calibration mode, the temperature measured by the furnace cover, furnace wall, furnace bottom thermocouple is added with the compensation temperature value ΔT(T) of the corresponding temperature point, so as to realize the temperature control calibration.

[0047] In general, the consistency of the whole between the temperature measuring thermocouples of the accelerated calorimeter is calibrated by simulating the sample heat generation by the resistance block. After the constant power provided by the constant current source twice, after a period of time, the temperatures of the furnace cover, furnace wall, furnace bottom and sample of the accelerated calorimeter reach thermal equilibrium near the step temperature control temperature point, at this time, the temperatures of each part of the furnace body have good consistency, and the temperature difference between the furnace wall and the cover bottom is also small. To eliminate the inconsistency between the thermocouples, the temperature indications of the sample, furnace cover, furnace wall and furnace bottom need to be corrected.

[0048] The improvement of temperature measurement consistency can not only be used to judge whether the temperature control meets the constant temperature condition, but also be used to judge whether the sample has started to react, that is, the exothermic detection function of the accelerated calorimeter. When the reaction starts, the temperature data of the sample is obtained first, and the temperatures of each part of the furnace cover, furnace wall and furnace bottom remain relatively consistent as T T ', T W ', T B ' after constant temperature control, the compensation temperature value ΔT(T) can be obtained, and for the target temperatures T1, T2 and T3 of the furnace cover, furnace wall and furnace bottom reaction detection, there are:

[0049] T1=T T '+ ΔT(T)

[0050] T2=T W '+ ΔT(T)

[0051] T3=T B '+ ΔT(T)

[0052] The temperature values measured by the furnace cover, furnace wall and furnace bottom thermocouples are corrected by the above formula, so that the temperature measured by the sample thermocouple and the temperature of the furnace cover, furnace wall and furnace bottom remain consistent, and the consistency of the thermocouples is calibrated.

[0053] Further, based on the heat balance equation, the heat generated by the Joule effect of the resistance block is used to simulate the adiabatic reaction exothermic of the sample, so as to realize the calibration of the detection performance of the accelerated calorimeter.

[0054] Embodiment:

[0055] This embodiment includes an accelerated calorimeter, a resistance block, a temperature measuring thermocouple, a constant current source, temperature measuring control software, etc.; a resistance block for calibrating the detection performance of the accelerated calorimeter needs to be designed. The specific structure diagram is shown in Figure 1 .

[0056] Figure 1 The resistance block is designed for calibrating the detection performance of the accelerated calorimeter, and the size of the resistance block is designed according to the size of the inner cavity of the accelerated calorimeter, the resistance block is a cuboid with a length of 5 cm, a width of 4 cm and a height of 3 cm, and is made of aluminum alloy, considering the uniformity of heat generation and the accuracy of temperature measurement, and a heating wire is uniformly placed in the interior, and the heating wire is wound in an S shape, and a heating rod is also used in the interior to meet the requirements, but the resistance block should generate heat uniformly, and the thermal conductivity of the material of the resistance block should be good, and the temperature rise lag of the material will also affect the accuracy of the thermocouple temperature measurement, and the positive and negative poles of the heating wire are led out from one end of the resistance block.

[0057] For the installation of the resistance block, the resistance block can be bundled with high-temperature-resistant ropes, and then fixed in the inner cavity of the accelerated calorimeter. The temperature measurement thermocouple, i.e. the sample thermocouple, is pasted on one surface of the resistance block without gaps by using high-temperature adhesive tape, so as to reduce the heat loss and affect the temperature measurement effect of the sample thermocouple. During the calibration experiment of the accelerated calorimeter, a constant current source is used to provide two different electric powers P1 and P2 according to the above principle. According to the Joule heat effect of the resistance block, the electric power provided by the constant current source is equal to the heat generation power of the resistance block, so as to simulate the heat generation of the sample by using the resistance block.

[0058] The resistance block designed by the above method additionally needs a constant current source for providing constant electric power to the resistance block. The constant current source can provide a maximum current of 4 A and a maximum voltage of 50 V, and the electric power P required by the resistance block in the calibration experiment is small, and the output power of the constant current source meets the experimental requirements.

[0059] In the application, the resistance block is connected to the constant current source for temperature measurement by using four-wire connection, as shown in the schematic view. Figure 2 The resistance block is connected to the constant current source for temperature measurement by using four-wire connection, as shown in the schematic view. Figure 4 The four-wire resistance connection is an ideal connection mode for thermal resistance temperature measurement, the constant current source applies an excitation current I to the resistance block through wires L1 and L2, the potential V3 and V4 are measured, wires L3 and L4 are connected to a high input impedance circuit, IL3=0 and IL4=0, so V4-V3 is equal to the voltage across the thermal resistance. Its power is P=UI. The circuit schematic diagram is as shown in

[0060] According to the requirements of the experiment, the experimental apparatus used is connected correspondingly. For example Figure 2As shown in the schematic diagram of experimental apparatus connection, the resistance block for calibration is fixed in the inner cavity of the accelerated calorimeter, one end with an electrode is connected with the constant current source through wires by the four-wire connection method, and the resistance block is supplied with electric power by the constant current source. The accelerated calorimeter controls the temperature of the furnace body at the corresponding step temperature points.

[0061] According to the principle described in the technical solution and Figure 3 The calibration experiment is operated as shown in the principle diagram. From the shape of the principle diagram, the calibration experiment mode is similar to the HWS mode of the accelerated calorimeter, and the temperature of the sample and the furnace cover, furnace wall and furnace bottom slowly rises in steps. As can be seen from the diagram, the calibration mode can calibrate each step temperature point. The step-by-step calibration experiment operation steps are as follows:

[0062] The temperature range of the calibration mode is 50-500℃, 50℃ is taken as the initial step temperature control temperature point, the temperature rising step is 10℃, the end temperature is 500℃, and 45 step temperature points are divided. Of course, the number of steps can be reduced by adjusting the temperature rising step, so that the high and low temperature adiabatic performance of the accelerated calorimeter can be further calibrated. After the accelerated calorimeter is heated to the initial step temperature control temperature point, the temperature is controlled to be constant, and the resistance block is supplied with a current by the constant current source, which is equivalent to indirectly supplying the resistance block with a constant power. After a period of time, the furnace body and the resistance block reach a thermal equilibrium state, and at this time, the temperature of the resistance block has a certain difference from the temperature value when the state is balanced. Due to the long-term drift of the thermocouple, there is inconsistency in temperature measurement, so the temperature of the sample and the furnace cover, furnace wall and furnace bottom will deviate. Considering the influence of this error, under the premise of ensuring the adiabatic performance of the accelerated calorimeter, a constant electric power is again provided to the resistance block, and the electric power provided by the constant current source before and after is not equal. The mathematical expression of the heat loss Q caused by the inconsistency of the sample thermocouple and the furnace cover, furnace wall and furnace bottom thermocouple is obtained by the heat balance formula, and the compensation temperature AT(T) relative to the whole accelerated calorimeter is solved, i.e. the temperature difference between the sample and the furnace cover, furnace wall and furnace bottom needs to be compensated. Since the temperature measurement difference between the thermocouples is inconsistent at different temperatures, a polynomial fitting needs to be performed on each step temperature point T to derive the fitting formula of AT(T). After obtaining the fitting formula, the corresponding AT(T) can be solved by knowing the corresponding temperature point value, so that the temperature of the furnace cover, furnace wall and furnace bottom is numerically corrected, i.e. the consistency of the sample thermocouple and the furnace cover, furnace wall and furnace bottom thermocouple is calibrated. The calibration operation flowchart is as shown in Figure 5As shown, the same step for each temperature point calibration, each step temperature point corresponds to a compensation temperature ΔT (T), so that the formula to correct the calorimeter in the temperature range of 50-500 ℃ thermocouple between the temperature consistency; the temperature measured by the furnace and the sample temperature value will be nearly consistent, also compensate for the four parts of the calorimeter thermocouple between the temperature non-uniformity caused by the heat loss of this part, complete the corresponding calibration work.

Claims

1. A method for calibrating the performance of an accelerated calorimeter based on the Joule effect of resistance, characterized in that: a constant current source is used to provide two different electric powers to a resistance block placed in the accelerated calorimeter, and a mathematical expression of the electric power is derived according to the heat balance formula; The heat loss Q caused by the temperature inconsistency of the thermocouples at the resistance block, the furnace cover, the furnace wall and the furnace bottom is calculated, and then the compensation temperature AT of the accelerating calorimeter furnace cover, the furnace wall and the furnace bottom is solved ; According to the obtained ΔT When the temperature of each step of the system reaches a steady state equilibrium, the temperature measured by the thermocouples on the furnace cover, furnace wall and furnace bottom is added to ΔT Corrected; the mathematical expression of the electric power is as follows: wherein Kc is the equivalent heat transfer coefficient of the cover; Kw is the equivalent heat transfer coefficient of the wall; Kb is the equivalent heat transfer coefficient of the bottom; Tc is the temperature value measured by the cover thermocouple; Tc is the temperature value measured by the cover thermocouple; Tc is the temperature value measured by the cover thermocouple; Tc is the temperature value measured by the cover thermocouple, P is the electric power provided by the constant current source; the heat balance equation of the resistance block after receiving two different constant electric powers is as follows: wherein, respectively, are the temperature differences of the resistance block at a given different electric power and the temperature differences of the furnace cover, furnace wall and furnace bottom in the steady state equilibrium state; X is the deviation of the non-consistency of the resistance block thermocouple and the furnace cover thermocouple temperature measurement; Y is the deviation of the non-consistency of the resistance block thermocouple and the furnace wall thermocouple temperature measurement; Z is the deviation of the non-consistency of the resistance block thermocouple and the furnace bottom thermocouple temperature measurement. The compensation temperature ΔT is solved as follows: Further simplifying gives: ΔT wherein P1 is the electrical power provided by the constant current source for the first time at the same temperature point; P2 is the electrical power provided by the constant current source for the second time at the same temperature point; ΔT A polynomial fit was used: ΔT wherein is the coefficient before the corresponding polynomial; T is the temperature value of the temperature control.

2. The method for calibrating the performance of an accelerated calorimeter based on the Joule effect of resistance according to claim 1, characterized in that: the resistance block is made of aluminum alloy material and a heating wire is uniformly placed inside, one end of the resistance block leads out the positive and negative poles of the heating wire, and a constant current source is used to directly heat the heating wire by four-wire connection method.

3. The method for calibrating the performance of an accelerated calorimeter based on the Joule effect of electrical resistance according to claim 2, characterized in that: the heating wire is wound in S shape.

4. The method for calibrating the performance of an accelerated calorimeter based on the Joule effect of electrical resistance according to claim 1, characterized in that: the thermocouple temperature value is corrected as follows: wherein Tc is the temperature measured by the furnace cover thermocouple when the system is in thermal equilibrium; Tw is the temperature measured by the furnace wall thermocouple when the system is in thermal equilibrium; Tb is the temperature measured by the furnace bottom thermocouple when the system is in thermal equilibrium; Tcset is the target temperature for the furnace cover thermocouple reaction detection; Twset is the target temperature for the furnace wall thermocouple reaction detection; Tbset is the target temperature for the furnace bottom thermocouple reaction detection.

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