CN114384113B - Single-sided double-probe explosive heat conductivity coefficient measurement method - Google Patents

Single-sided double-probe explosive heat conductivity coefficient measurement method Download PDF

Info

Publication number
CN114384113B
CN114384113B CN202111352258.4A CN202111352258A CN114384113B CN 114384113 B CN114384113 B CN 114384113B CN 202111352258 A CN202111352258 A CN 202111352258A CN 114384113 B CN114384113 B CN 114384113B
Authority
CN
China
Prior art keywords
sample
temperature
probe
measured
measuring
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202111352258.4A
Other languages
Chinese (zh)
Other versions
CN114384113A (en
Inventor
王晓红
陈曼
温晓燕
赵嘉静
高朗华
孙晓朋
康莹
何少蓉
张皋
王一凯
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xian Jiaotong University
Xian Modern Chemistry Research Institute
Original Assignee
Xian Jiaotong University
Xian Modern Chemistry Research Institute
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Xian Jiaotong University, Xian Modern Chemistry Research Institute filed Critical Xian Jiaotong University
Priority to CN202111352258.4A priority Critical patent/CN114384113B/en
Publication of CN114384113A publication Critical patent/CN114384113A/en
Application granted granted Critical
Publication of CN114384113B publication Critical patent/CN114384113B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/20—Investigating or analyzing materials by the use of thermal means by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity

Landscapes

  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analyzing Materials Using Thermal Means (AREA)

Abstract

The invention discloses a single-sided double-probe explosive thermal conductivity coefficient measuring method, which comprises the steps of placing a sample to be measured on a sample bearing table of a measuring system, and closing a box door; setting the temperature in the incubator as T, wherein the T is any one of temperatures within a range of-50-70 ℃, adjusting the temperature detector to enable the contact tip of the probe to be in close contact with the surface of the sample to be measured after the temperature in the incubator is stable, starting measurement, stopping measurement after the measurement time exceeds 10 minutes, obtaining m groups of measurement results of the current position of the sample to be measured, and calculating the heat conductivity value; the contact positions of the probe contacts of the temperature detector and the sample to be detected are adjusted to obtain the heat conductivity coefficients of different positions; repeating the above process to obtain the heat conductivity coefficients of different temperature points; the invention has the advantages of rapid and convenient measuring process, simultaneous measurement of a plurality of samples and continuous measurement of a plurality of temperature points at one time, reduced measuring error caused by environmental temperature change in multiple times of measurement and improved accuracy.

Description

Single-sided double-probe explosive heat conductivity coefficient measurement method
Technical Field
The invention belongs to the technical field of measurement of thermal physical properties of explosives and powders, and particularly relates to a single-sided double-probe measurement method of thermal conductivity coefficients of explosives and powders.
Background
In the design and shaping research of the formula of the explosives and powders, in order to ensure the safety of the environment of the explosives and powders, it is necessary to grasp the heat conductivity of the explosives and powders and related materials and the related data thereof within the temperature range of (-50-70) DEG C. With the development of novel high-energy explosive charges, missile charges, propellants, novel energetic materials and products thereof, the thermal conductivity coefficients of the explosives and related materials and the accurate measurement of the thermal conductivity coefficients have extremely important theoretical and practical significance for the material selection, formula design, performance prediction and simulation of novel explosives and related products, and product shaping and theoretical model establishment. The current testing methods for the heat conductivity coefficients of the explosives and powders and related materials mainly comprise a thermal conductivity coefficient measuring method of a protective hot plate, a DSC method, a micro-thermal calorimeter method and a laser scintillation method.
The protection hot plate method requires that the sample is a round sample or a square sample, the processed sample has flat and smooth surface, no air hole, greasy dirt and mechanical damage, the explosive is pressed into tablets, the heat conductivity coefficient is less than 1.5W/m.K, the temperature of the heating plate is not more than 333K when the explosive is measured, and the temperature of the heating plate is not more than 400K when the coating layer and the heat insulation layer are measured. The method has the advantages that the size and the sample quantity of the sample are large, the sample is required to be pressed and clamped by the guard board during the test, and the tight contact between the hot plate and the surface of the sample is ensured, so that the local heat accumulation of the sample to be tested is often caused to form hot spots due to the overhigh local temperature, and potential safety hazards are caused for the novel high-damage energetic material heat conductivity coefficient test; the micro-thermal calorimeter requires concentric circles of the outer diameter and the inner diameter of the grain, the surface of the inner diameter is smooth and lossless, the test range of the heat conductivity coefficient is 0.001-0.5W/m.K, the temperature range is-50 ℃, the problems of high sample preparation difficulty, high risk, very accurate size requirement, large measurement error caused by the size error, and a heating unit arranged in the inner hole during the test, and for the existing novel explosive material, the potential safety hazard is serious, the test needs very long time, and the heat conductivity coefficient of one temperature point of one sample usually needs 24 hours; DSC method requires that the sample is a right cylinder, the end face is smooth and clean, no crack exists, and the heat conductivity coefficient is smaller than1.5W/m.K, the problems are that the sample quantity is too small, the uniformity is difficult to ensure, the test accuracy is poor, the sample needs a special test support, the operation is complex, the test time is long, and 5 hours are needed for completing the thermal conductivity coefficient test of one temperature point of one sample. Sample size in laser scintillation methodOr->The thickness is 2-3 mm, the testing temperature range can reach-125-2000 ℃, the thermal conductivity coefficient range can reach 0.1-2000W/mK, the method has the advantages of wide testing range, small sample size, short testing time and multiple testing performances, and the method has the disadvantages of poor temperature measurement and control precision and stability of an instrument measuring system, and is suitable for testing the thermal conductivity coefficient of homogeneous medium-high thermal conductivity coefficient materials such as metals. Meanwhile, as the instantaneous energy of the laser beam is larger, the laser beam is used for energetic materials such as explosives and the like, which are extremely easy to cause safety problems such as combustion, explosion and the like.
In summary, the existing methods and techniques have the following disadvantages:
1) The prior protective hot plate method and laser scintillation heat conductivity coefficient testing method have the defects that the size of a required sample is too large, and the method is suitable for heat conductivity coefficient testing of materials such as refractory heat preservation, ceramic fiber, felt, textile, plate, brick and the like; the latter is suitable for testing materials with medium and high heat conductivity coefficient, such as metal materials with heat conductivity coefficient, due to the limitation of the test principle. Aiming at the special inflammable and explosive properties of the explosive material, both devices cannot meet the requirements of the novel explosive material on heat conductivity coefficient test.
2) The standard measurement method for the thermal conductivity coefficient of the explosive material has the defects of high sample preparation difficulty, high risk, overlong test period, method self defect, ageing elimination of instruments and equipment and the like, and cannot meet the requirements of accurate measurement of the thermal conductivity coefficient of the existing explosive material and product at present, and is rarely used in scientific research and production.
Disclosure of Invention
Aiming at the problems, the invention provides a single-sided double-probe method for measuring the thermal conductivity coefficient of the explosive and the powder, which aims to achieve the effects of being quick and safe, being capable of covering a plurality of temperature points in the life cycle temperature range of the explosive and the powder and accurately obtaining the thermal conductivity coefficient of the explosive and the powder.
The invention is realized by adopting the following technical scheme:
the single-sided double-probe explosive and powder heat conductivity coefficient measuring method is characterized in that the single-sided double-probe explosive and powder heat conductivity coefficient measuring system is adopted for measuring, and comprises an incubator, a sample bearing table for placing a sample and a temperature detector for detecting the temperature of the sample; the sample bearing table and the temperature detector are both arranged in the incubator, and the temperature detector is arranged above the sample bearing table; the temperature detector comprises a thermopile and two probes respectively connected with the cold end and the hot end of the thermopile;
the specific measurement method comprises the following steps:
step 1, placing a sample to be tested on a sample bearing table of the single-sided double-probe explosive thermal conductivity coefficient measuring system, and closing a box door; the processing of the sample to be detected requires that the surface is flat and smooth, and no air holes, greasy dirt and mechanical damage exist;
step 2, setting the temperature in the incubator to be T, wherein the T is any one temperature within the range of-50-70 ℃, after the temperature in the incubator is stable, adjusting the temperature detector to enable the contact of the probe to be in close contact with the surface of the sample to be measured, starting measurement, stopping measurement after the measurement time exceeds 10 minutes, obtaining m groups of measurement results of the current position of the sample to be measured, wherein each group of measurement results comprises the temperature theta of the hot end of the thermopile l1 Cold end temperature θ of thermopile 12 Bottom temperature θ of two probe tips 01 、θ 02 Calculating the corresponding heat conductivity value of each group of measurement results by adopting a formula,
wherein A is 1 、A 2 、A 3 All represent intermediate quantities, R is the radius of the probe tip, R c Is the contact thermal resistance of the probe contact, s is the axial cross-sectional area of the probe, l is the length of the probe, p is the perimeter of the probe, h is the heat exchange coefficient of the air convection surface, lambda t Is the heat conductivity coefficient of the probe material;
finally obtaining m heat conductivity coefficient measurement results of the current position of the sample to be measured;
step 3, the contact positions of the probe contact of the temperature detector and the sample to be measured are adjusted for multiple times, so that the contact positions of the probe contact and the surface of the sample to be measured are different each time, and the measurement is carried out according to the measurement mode of the step 2 after the contact positions are adjusted each time;
finally obtaining n multiplied by m heat conductivity coefficient measurement results, wherein n is the contact position adjustment times of the probe contact and the sample to be measured;
step 4, according to the test requirement, if the measurement results of other temperature points within the range of-50-70 ℃ are needed, resetting the temperature in the incubator to the needed temperature points, measuring the set temperature from high temperature to low temperature in sequence, and repeating the steps 2 to 3 to obtain the measurement results of the heat conductivity coefficients of all the needed temperature points;
step 5, taking the average value of m heat conductivity coefficient results of each measuring position of each temperature point of the sample to be measured as the heat conductivity coefficient value of one measuring position of one temperature point; then, carrying out the same processing on the data of the n measuring positions to obtain n heat conduction coefficient values of the to-be-measured sample at one temperature point, and taking the average value of the n heat conduction coefficient values as the heat conduction coefficient value of the to-be-measured sample at one temperature point;
and finally obtaining the heat conductivity values corresponding to all the required temperature points of the sample to be tested.
Preferably, m is greater than or equal to 10; n is more than or equal to 6.
Preferably, the oven door of the incubator is an automatic switch door controlled by the pressure of the air compressor, and when the pressure of the air compressor reaches 7-10 atmospheres, the oven door can be tightly closed.
Preferably, the sample loading table comprises a bracket and a tray, the tray can rotate, and when the contact position of the temperature detector is adjusted to the contact position of the sample to be measured: the temperature detector is adjusted to enable the contact head of the probe to leave the sample to be detected, then the sample to be detected is rotated to a certain angle, and the temperature detector is adjusted to enable the contact head of the probe to be closely contacted with the surface of the sample to be detected again.
Preferably, the number of the samples to be tested is at least 3, each tray is provided with one sample to be tested with the same material, the same size and specification, and each sample to be tested corresponds to one temperature detector.
Preferably, the sample to be measured is a circular sample.
Preferably, a first-stage difference thermocouple is arranged in the probe and used for measuring the bottom temperature of a probe contact, and a second-stage difference thermocouple is arranged in the thermopile and used for measuring the temperatures of the cold end and the hot end of the thermopile; the first-stage difference thermocouple and the second-stage difference thermocouple are respectively connected with the data acquisition and processing unit.
Preferably, the stylus of the probe is arranged in a frustum shape.
Compared with the prior art, the invention has the beneficial effects that:
(1) The invention can realize the measurement of a plurality of temperature points within the (-50-70) DEG C range in the life cycle of the explosives and powders, the measurement process is quick and convenient, and the measurement of one temperature point only needs a few minutes; and simultaneously, simultaneous measurement of a plurality of samples and continuous measurement of a plurality of temperature points can be realized, the measurement error caused by environmental temperature change in repeated measurement is effectively reduced, and the measurement accuracy is greatly improved.
(2) The invention adopts the principle of single-sided double-probe measurement, can realize the small-area contact between the contact head and the explosive sample, and avoids the potential safety hazard of thermal effect caused by long-time contact.
Other advantages of the present invention are described in detail in the detailed description.
Drawings
Fig. 1 is a block diagram showing the configuration of a thermal conductivity measurement system according to embodiment 1.
Fig. 2 is a schematic diagram of the measurement method of the present invention.
Fig. 3 is a schematic structural diagram of the temperature probe of the present invention.
The reference numerals in the drawings illustrate:
the device comprises a 1-incubator, a 2-sample bearing table, a 3-temperature detector, a 4-data acquisition and processing unit, a 5-temperature control system, a 6-sample to be tested and a 7-air compressor;
31-thermopile, 32-probe, 33-first level difference thermocouple, 34-second level difference thermocouple; 321-contacts.
Detailed Description
The invention discloses a single-sided double-probe explosive thermal conductivity measurement method, which is based on the principle of heat transfer and the Peltier principle, and obtains the thermal conductivity of an explosive material in a transient state under a certain temperature condition by tracking and detecting the temperature changes of contact points between the upper ends of probes of two temperature detectors and two ends of a thermopile and contact points between the lower ends of the probes and the surface of the explosive material.
The thermal conductivity is the thermal conductivity, and the physical meaning is the heat quantity passing through the unit surface area in unit time when the temperature difference in the unit thickness of the material is 1 ℃ under the condition of stable heat transfer. The heat quantity transferred in unit thickness and unit time under the conditions of unit temperature gradient and unit heat conduction area is a parameter for representing the heat conduction performance of the material, and is expressed as lambda, and the unit is W/(mK). The general mathematical expression is shown as a formula (1):
Q＝λ*(A/S)*ΔT (1)
wherein: q- -the heat per unit time flowing through the sample in W; a- -the object area, in m 2 The method comprises the steps of carrying out a first treatment on the surface of the S- - -objectThickness in m; delta T-the temperature difference of the cold and hot surfaces of the object, and the unit is K.
FIG. 1 is a schematic diagram of the thermal energy of the process of the present invention, wherein a) is a theoretical model; b) Is a dual bending characteristic of the temperature field on the sample surface. In FIG. 1, deltaT L For the temperature difference, deltaT, of the two probe 31 contacts at both ends contacting the material to be measured L ＝θ 01 -θ 02 ，θ 01 、θ 02 Respectively representing the bottom temperatures of the two probe contacts; delta T H After a certain current is supplied to the thermopile 32, the temperature difference delta T between the two ends of the probe H ＝θ l1 -θ l2 ，θ l1 、θ l2 Respectively representing the hot end temperature of the thermopile 32 and the cold end temperature of the thermopile, U 0 And a test temperature set for the incubator during testing. From the hemispherical heat conduction model, a relation between the heat conductivity coefficient of the material to be measured and the probe parameter and the probe temperature difference can be deduced, as shown in the formula (2).
Then the first time period of the first time period,
wherein:
A 1 ，A 2 ，A 3 all represent intermediate quantities, R is the radius of the probe tip, R c Is the contact thermal resistance of the probe tip,representing the intermediate calculated quantity, s is the axial cross-sectional area of the probe, l is the length of the probe, p is the perimeter of the probe, h is the heat exchange coefficient of the air convection surface, lambda t Is a probeThe thermal conductivity of the needle material; will->Substituting into the above formula, it is possible to obtain:
it can be seen that R, R c ,p,h,λ t S, l are physical parameters associated with the temperature probe, and are constant over a limited temperature interval for a model of a particular physical characteristic. For a fixed material to be measured and a temperature field, when the current applied to the thermopile is constant, deltaT H Is a constant value lambda 0 With delta T only L Related to the following. Therefore, the thermal conductivity of the sample to be tested can be obtained by testing the temperature difference at the two ends of the probe.
In order to realize the measuring method of the present invention, a single-sided double-probe explosive and powder thermal conductivity measuring system is designed, and specific embodiments of the measuring system and the measuring method of the present invention are given below, and the present invention is not limited to the following specific embodiments, and the specific technical features described in the following specific embodiments may be combined in any suitable manner without contradiction, so long as they do not violate the concept of the present invention, and should also be regarded as disclosure of the present invention.
Example 1
As shown in fig. 2, the single-sided dual-probe explosive thermal conductivity measurement system according to the embodiment includes a thermostat 1, a sample carrying table 2, a temperature detector 3, and a data acquisition and processing unit 4, wherein the sample carrying table 2 is used for placing a sample to be measured, the temperature detector 3 is used for detecting the temperature of the sample, the sample carrying table 2 and the temperature detector 3 are both arranged in the thermostat 1, and the temperature detector 3 is arranged above the sample carrying table 2.
The sample plummer 2 of this embodiment includes support and tray, and the sample that awaits measuring is placed to the tray, and temperature probe sets up in the tray top, and the tray can the rotation, realizes the measurement of temperature probe 3 to await measuring the different positions of sample. Specifically, the temperature detector 3 is suspended above the tray by a support capable of moving up and down, so that the temperature detector 3 can be moved conveniently.
The temperature detector 3 comprises a thermopile 31 and two probes 32, the two probes 32 are respectively connected with the cold end and the hot end of the thermopile 31, the thermopile 3 is connected with a constant current power supply, a contact 321 of the probe 32 is arranged in a frustum shape, and the contact area of the contact 321 and a sample 6 to be detected is increased, as shown in fig. 3.
The temperature detector 3 of the invention adopts the Bohr effect principle that two different metals form a closed loop, when a constant current power supply inputs a certain current to the thermopile 31, the two ends of the thermopile 31 generate a constant temperature difference, heat is transferred to the direction of the contact 321 through a thermal probe, the contact 321 is tightly contacted with a sample to be detected, and the two probe contacts 321 are in temperature theta 01 、θ 02 Measured by a first-stage difference thermocouple 33, the temperature θ across the thermopile 31 l1 、θ l2 Measured by a second level difference thermocouple 34.
The first-stage difference thermocouple 33 and the second-stage difference thermocouple 34 of the temperature detector 3 are connected with the data acquisition and processing unit 4, the measurement result is transmitted to the data acquisition and processing unit 4, and the data are processed and analyzed through a thermal conductivity coefficient calculation model (namely formula (3)) of the data acquisition and processing unit 4, so that the thermal conductivity coefficients of the explosive materials under different temperature conditions are obtained.
As can be seen from fig. 2, the data acquisition and processing unit 4 is also connected with the sample support and the incubator 1, and the data acquisition and processing unit 4 controls the lifting of the support of the temperature detector 3 and the rotation operation of the tray of the sample carrying table 2. The temperature control meter and the temperature sensor are also arranged in the incubator 1 and connected with the data acquisition and processing unit 4, so that the temperature in the incubator 1 is controlled and regulated.
In order to adjust the temperatures at two ends of the temperature detector thermopile 31, the embodiment further provides a temperature control system 5, as shown in fig. 2, the temperature control system 5 is used for providing constant current for the temperature detector 3 by using a constant current power supply, so that the two ends of the temperature detector thermopile 31 generate constant temperatures, and meanwhile, the interference of electromagnetic signals is filtered, so that the output current signals are stable and reliable.
Example 2
The embodiment discloses a single-sided double-probe explosive heat conductivity coefficient measuring method, which adopts the measuring system recorded in the embodiment 1 to measure, and comprises the following specific measuring methods:
and 1, placing a sample to be tested on a tray of the sample bearing table 2, and closing a box door. The environmental temperature of the sample to be measured is room temperature, generally 15-30 ℃, and the environmental humidity is not more than 80% RH;
the processing of the sample to be tested requires that the surface is flat and smooth, and no air holes, greasy dirt and mechanical damage exist. The sample to be measured in the embodiment is preferably a circular sample, and firstly is consistent with the processing technology of explosive materials, secondly can ensure the uniformity of the sample measurement process, and thirdly is consistent with the structural shape and the numerical simulation model of the detector.
Generally, the number of the samples to be measured is at least 3, each tray is internally provided with one sample to be measured with the same material and the same size specification, each sample to be measured corresponds to one temperature detector, parallel test is carried out, the accuracy of measurement results is improved, the detailed sizes of probes of different temperature detectors can slightly differ due to processing errors, and each temperature detector is provided with a number for convenience in distinguishing.
The oven door of the incubator 1 is an automatic switch door controlled by the pressure of the air compressor 7, and when the pressure of the air compressor 7 reaches 7-10 atmospheres, the oven door can be tightly closed.
Step 2, setting the temperature in the incubator 1 as T, wherein T is any one temperature within the range of-50-70 ℃, adjusting the temperature detector 3 to enable the contact 321 of the probe to be in close contact with the surface of the sample to be measured after the temperature in the incubator 1 is stable, measuring the temperature difference between the two probes 32, and measuring the temperature difference after the measurement time exceeds 10 minutesStopping measurement to obtain m groups of measurement results of the current position of the sample to be measured, wherein m is more than or equal to 10; each set of measurements includes the thermopile hot side temperature θ l1 Cold end temperature θ of thermopile l2 Bottom temperature θ of two probe tips 01 、θ 02 The four temperature values are then used to calculate the corresponding heat conductivity value of each group of measurement results by adopting the formula (3);
finally obtaining m heat conductivity coefficient measurement results of the current position of the sample to be measured;
step 3, the contact positions of the contact 321 of the temperature detector 3 and the sample to be measured are adjusted for multiple times, so that the contact positions of the contact 321 and the surface of the sample to be measured are different each time, and the measurement is carried out according to the measurement mode of step 2 after the contact positions are adjusted each time;
preferably, when adjusting the contact position of the contact 321 of the temperature probe 3 with the sample to be measured: the position of the temperature detector 3 is adjusted to enable the contact 321 of the probe to leave the sample to be detected, then the tray is rotated to a certain angle, and the temperature detector 3 is adjusted to enable the contact 321 of the probe to be closely contacted with the surface of the sample to be detected again.
Finally obtaining n multiplied by m temperature difference measurement results, wherein n is the contact position adjustment times of the probe contact and the sample to be measured, and n is more than or equal to 6;
step 4, if measurement results of other temperature points within the range of-50-70 ℃ are required according to the test requirements, resetting the temperature in the incubator 1 to the required temperature point, and taking care that the temperature is set to be measured from high temperature to low temperature in sequence, so that the influence on the accuracy of the measurement results due to the condensation of water vapor can be avoided; repeating the steps 2 to 3 to obtain measurement results of all required temperature points;
step 5, taking the average value of m heat conductivity coefficient results of each measuring position of each temperature point of the sample to be measured as the heat conductivity coefficient value of one measuring position of one temperature point; then, carrying out the same processing on the data of the n measuring positions to obtain n heat conduction coefficient values of the to-be-measured sample at one temperature point, and taking the average value of the n heat conduction coefficient values as the heat conduction coefficient value of the to-be-measured sample at one temperature point; and finally obtaining the heat conductivity values corresponding to all the required temperature points of the sample to be tested.
The repeatability and accuracy of the measurement method described in the above examples were verified as follows:
the test conditions of the measurement system are: the current amount is 0.8-1A; temperature range: the temperature detector has a measuring range of 0.02-2.00W/(m.K) and a constant temperature time of not less than 30min at each temperature point of the incubator, and a data result with a measuring frequency of 10s is obtained by taking the temperature points at intervals of 10 ℃ of 50-70 ℃.
The sample to be measured isAnd 4 identical samples to be tested are arranged at each temperature point of the round sample for parallel test.
When the contact position of the contact 321 and the sample to be measured is adjusted, the temperature detector 3 is adjusted to be raised to enable the contact 321 of the probe to leave the sample to be measured, then the tray is rotated clockwise for 60 degrees, and then the temperature detector 3 is adjusted to be lowered to enable the contact 321 of the probe to be in close contact with the surface of the sample to be measured again, so that 6 measurement results, namely n=6, can be obtained at one temperature point. Each temperature point takes 10 results per rotation angle, i.e. m=10.
In the following specific embodiments, the values of the parameters are respectively: the temperature detector is a copper detector, the inner diameter of the probe is 0.5mm, the outer diameter of the probe is 1.2mm, the length l of the probe is 12mm, and the contact area of the equal cone cap is 3mm 2 I.e. pi R 2 ＝3mm,λ t And h is the heat conductivity coefficient of copper and h is the heat conductivity coefficient of the air convection surface.
In the measurement process, the test time is set to be 5 minutes, the test temperature is 25 ℃, the constant current is 1A, the rotation angle is 60 degrees, and the lifting distance of the temperature detector is 2cm.
(1) Repeatability test
The experiment was independently conducted 11 times under the same test conditions at room temperature of 25 ℃ by using the method of the present invention using self-grinding large thermal coefficient standard substances of organic glass, borosilicate glass, quartz glass and TF-3 glass, and the experimental data are shown in the following Table 1.
Table 1 method repeatability test data
As can be seen from the experimental data in Table 1, the relative standard deviation of the repeatability of the method of the present invention is less than or equal to 3.0%.
(2) Accuracy experiment
The thermal conductivity of the standard substances of organic glass, borosilicate glass, quartz glass and TF-1 glass developed by Russian Siberian metering institute is measured by the method at room temperature of 25 ℃, and the measured result is compared with the standard value given by the Russian Siberian metering institute to obtain the final productWhen uncertainty of standard substance is k=2 as criterion, U rel =3.0%. The results of the verification are shown in table 2.
Table 2 method accuracy verification data
As can be seen from the results in Table 2, for four standard substances, the test results obtained by the measurement method of the present invention are all in accordance with the standard valuesThe measuring method is accurate and reliable.
In addition, the standard organic glass is tested by using a hot wire method and the measuring method, the organic glass value obtained by using the hot wire method is 0.2052W/(m.K), the thermal conductivity value of the organic glass obtained by using the measuring method is 0.2036W/(m.K), and the thermal conductivity value obtained by using the measuring method is basically consistent with the thermal conductivity value obtained by using the hot wire method.

Claims (8)

1. The single-sided double-probe explosive and powder heat conductivity coefficient measuring method is characterized in that the single-sided double-probe explosive and powder heat conductivity coefficient measuring system is adopted for measuring, and comprises an incubator (1), a sample bearing table (2) for placing a sample and a temperature detector (3) for detecting the temperature of the sample; the sample bearing table (2) and the temperature detector (3) are both arranged in the incubator (1), and the temperature detector (3) is arranged above the sample bearing table (2); the temperature detector (3) comprises a thermopile (31) and two probes (32) respectively connected with the cold end and the hot end of the thermopile (31);
the specific measurement method comprises the following steps:
step 1, placing a sample to be tested on a sample bearing table (2) of the single-sided double-probe explosive thermal conductivity measuring system, and closing a box door; the processing of the sample to be tested requires that the surface is flat and smooth, and no air holes, greasy dirt and mechanical damage exist;
step 2, setting the temperature in the incubator (1) to be T, wherein T is any one of temperatures within a range of-50-70 ℃, adjusting the temperature detector (3) to enable the contact of the probe (32) to be in close contact with the surface of the sample to be measured after the temperature in the incubator (1) is stable, starting measurement, stopping measurement after the measurement time exceeds 10 minutes, and obtaining m groups of measurement results of the current position of the sample to be measured, wherein each group of measurement results comprises the temperature theta of the hot end of the thermopile (31) l1 Cold end temperature θ of thermopile l2 Temperature θ at the bottom of the two probe (32) tips 01 、θ 02 Calculating the heat conductivity value corresponding to each group of measurement results by adopting a formula (3),
wherein A is 1 、A 2 、A 3 All represent intermediate quantities, R is the radius of the probe tip, R c Is the contact thermal resistance of the probe contact, s is the axial cross-sectional area of the probe, l is the length of the probe, p is the perimeter of the probe, h is the heat exchange coefficient of the air convection surface, lambda t Is the heat conductivity coefficient of the probe material;
finally obtaining m heat conductivity coefficient measurement results of the current position of the sample to be measured;
step 3, the contact positions of the probe (32) contact of the temperature detector (3) and the sample to be measured are adjusted for multiple times, so that the contact positions of the probe (32) and the surface of the sample to be measured are different each time, and the measurement is carried out according to the measurement mode of step 2 after the contact positions are adjusted each time;
finally obtaining n multiplied by m heat conductivity coefficient measurement results, wherein n is the contact position adjustment times of the probe contact and the sample to be measured;
step 4, according to the test requirement, if the measurement results of other temperature points within the range of-50-70 ℃ are needed, resetting the temperature in the incubator (1) to the needed temperature point, measuring the set temperature from high temperature to low temperature in sequence, and repeating the steps 2 to 3 to obtain the measurement results of the heat conductivity coefficients of all the needed temperature points;
step 5, taking the average value of m heat conductivity coefficient results of each measuring position of each temperature point of the sample to be measured as the heat conductivity coefficient value of one measuring position of one temperature point; then, carrying out the same processing on the data of the n measuring positions to obtain n heat conduction coefficient values of the to-be-measured sample at one temperature point, and taking the average value of the n heat conduction coefficient values as the heat conduction coefficient value of the to-be-measured sample at one temperature point;
and finally obtaining the heat conductivity values corresponding to all the required temperature points of the sample to be tested.
2. The method for measuring the heat conductivity coefficient of the single-sided double-probe explosive according to claim 1, wherein m is more than or equal to 10; n is more than or equal to 6.
3. The method for measuring the heat conductivity coefficient of the single-sided double-probe explosives and powders according to claim 1, wherein the oven door of the incubator (1) is an automatic switch door controlled by the pressure of an air compressor, and when the pressure of the air compressor reaches 7-10 atmospheres, the tight closing of the oven door can be realized.
4. The method for measuring the thermal conductivity of the single-sided double-probe explosives and powders according to claim 1, wherein the sample carrying table (2) comprises a bracket and a tray, the tray can rotate automatically, and when the contact position of a contact (321) of the temperature detector (3) and a sample to be measured is adjusted: firstly, the temperature detector (3) is adjusted to enable the contact head (321) of the probe to leave the sample to be tested, then the sample to be tested is rotated to a certain angle, and then the temperature detector (3) is adjusted to enable the contact head (321) of the probe to be closely contacted with the surface of the sample to be tested again.
5. The method for measuring the thermal conductivity of the single-sided double-probe explosives and powders according to claim 2, wherein the number of the to-be-measured samples is at least 3, each tray is provided with one to-be-measured sample with the same material, the same size and the same specification, and each to-be-measured sample corresponds to one temperature detector.
6. The method for measuring the thermal conductivity of the single-sided dual-probe explosive according to claim 1, wherein the sample to be measured is a circular sample.
7. The single-sided double-probe explosive thermal conductivity measuring method according to claim 1, wherein a first-stage difference thermocouple (33) is arranged in the probe (32) and used for measuring the bottom temperature of a contact of the probe (32), and a second-stage difference thermocouple (34) is arranged in the thermopile (31) and used for measuring the temperature of a cold end and a hot end of the thermopile (31); the first-stage difference thermocouple (33) and the second-stage difference thermocouple (34) are respectively connected with the data acquisition and processing unit (4).
8. The method for measuring the thermal conductivity of the single-sided dual probe explosives and powders according to claim 1, wherein the contact of the probe (32) is arranged in a frustum shape.
CN202111352258.4A 2021-11-16 2021-11-16 Single-sided double-probe explosive heat conductivity coefficient measurement method Active CN114384113B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111352258.4A CN114384113B (en) 2021-11-16 2021-11-16 Single-sided double-probe explosive heat conductivity coefficient measurement method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111352258.4A CN114384113B (en) 2021-11-16 2021-11-16 Single-sided double-probe explosive heat conductivity coefficient measurement method

Publications (2)

Publication Number Publication Date
CN114384113A CN114384113A (en) 2022-04-22
CN114384113B true CN114384113B (en) 2023-07-18

Family

ID=81195557

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111352258.4A Active CN114384113B (en) 2021-11-16 2021-11-16 Single-sided double-probe explosive heat conductivity coefficient measurement method

Country Status (1)

Country Link
CN (1) CN114384113B (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101788513A (en) * 2010-03-25 2010-07-28 上海海洋大学 Measurement device of thermal conductivity of materials and method thereof
FR2953598A1 (en) * 2009-12-08 2011-06-10 Rhodia Operations METHOD AND DEVICE FOR CHARACTERIZING SOLID MATERIALS, AND METHOD AND PLANT FOR DETERMINING A THERMODYNAMIC CHARACTERISTIC OF PROBE MOLECULES
CN112730513A (en) * 2021-01-07 2021-04-30 湖北航天化学技术研究所 Method for measuring convective heat transfer coefficient

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10288572B2 (en) * 2014-08-11 2019-05-14 The United States Of America, As Represented By The Secretary Of The Navy Apparatus for destructive event testing of chemical energy systems using highly portable and ease of access adaptive heat flow testing systems including replaceable and thermally isolated modular thermal sections each capable of independent measurements of a test article with improved ease of test article insertion and removal and related methods

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2953598A1 (en) * 2009-12-08 2011-06-10 Rhodia Operations METHOD AND DEVICE FOR CHARACTERIZING SOLID MATERIALS, AND METHOD AND PLANT FOR DETERMINING A THERMODYNAMIC CHARACTERISTIC OF PROBE MOLECULES
CN101788513A (en) * 2010-03-25 2010-07-28 上海海洋大学 Measurement device of thermal conductivity of materials and method thereof
CN112730513A (en) * 2021-01-07 2021-04-30 湖北航天化学技术研究所 Method for measuring convective heat transfer coefficient

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
用微热量热法测定含能材料的导热系数;胡荣祖，李楠，楚士晋，陈学林;应用科学学报(第02期);全文 *

Also Published As

Publication number Publication date
CN114384113A (en) 2022-04-22

Similar Documents

Publication Publication Date Title
CN203365021U (en) Portable temperature calibrator
Panda et al. Thermal shock and thermal fatigue study of ceramic materials on a newly developed ascending thermal shock test equipment
CN102944466A (en) Device and method for testing mechanical property in ultrahigh temperature oxidation environment
CN102012382B (en) Heat conductivity coefficient quick test device and method of vacuum insulating board
CN109752113B (en) Sheet temperature sensor, position determining method and circuit design method in application of sheet temperature sensor
CN103464233B (en) A kind of Portable thermostatic bath
CN108020578B (en) Detection equipment for assimilation temperature of iron ore powder and assembly and detection method thereof
CN109324079B (en) Material thermal expansion coefficient measuring method based on ultrasound
CN114384113B (en) Single-sided double-probe explosive heat conductivity coefficient measurement method
CN103389320B (en) A kind of measurement mechanism with the radial Equivalent Thermal Conductivities of roll of material and measuring method
CN203350207U (en) Strip coil material radial equivalent heat conductivity coefficient measurement device
CN112858381B (en) Heat insulation performance test device and test method for heat insulation material for high-speed aircraft engine
CN111443106B (en) Method and system for testing equivalent thermal conductivity coefficient of heterogeneous material
CN102426129A (en) Sample heating device used in integrating-sphere reflectivity measurement
CN107966472B (en) Nondestructive rapid measurement method for high-temperature contact thermal resistance
CN106053530B (en) The calculation method of Refractory Thermal Conductivity
CN203629720U (en) Thermal paint temperature detection device
CN100439900C (en) Method for testing material blackness coefficient
CN202372397U (en) Sample heating device for measuring reflectivity of integrating sphere
Pearce Quantitative determination of the uncertainty arising from the inhomogeneity of thermocouples
Babak et al. Hardware-Software System for Measuring Thermophysical Characteristics of the Materials and Products.
SU958937A1 (en) Thermal resistance determination method
CN111426897A (en) Device and method for detecting characteristics of heating device of heating non-combustion type cigarette
CN204988933U (en) Casting sand gas -forming property testing arrangement
CN100424503C (en) Pyroelectric coefficient measuring device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
TA01 Transfer of patent application right

Effective date of registration: 20220817

Address after: 710065 Shaanxi Province, Xi'an City Road eight No. 168

Applicant after: XI'AN MODERN CHEMISTRY Research Institute

Applicant after: XI'AN JIAOTONG University

Address before: 710065, No. eight, No. 168 East Road, Yanta District, Shaanxi, Xi'an

Applicant before: XI'AN MODERN CHEMISTRY Research Institute

TA01 Transfer of patent application right
GR01 Patent grant
GR01 Patent grant