CN111474204B - Method for testing heat conductivity coefficient of cylindrical sample by punching method - Google Patents
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Abstract
The invention discloses a method for testing the heat conductivity coefficient of a cylindrical sample by a punching method, which comprises the following steps: s11, selecting a sample to be detected and a A, B reference sample with different known heat conductivity coefficients, and processing the sample to be detected and the A, B reference sample into a sample with the same diameter and heightEqual cylinders; s12, radially processing two temperature measuring holes on the side wall of each cylinder; step S13, a thermal conductivity tester in a flat-plate steady-state method is adopted to respectively measure and calculate thermal conductivity test values of a sample to be measured and a A, B reference sample; step S14, estimating the real heat conductivity coefficient lambda of the sample to be detected by adopting a linear interpolation method * . The method for testing the heat conductivity coefficient of the cylindrical sample by the punching method realizes the test of the heat conductivity coefficient of the small nonstandard cylindrical sample by using common steady-state heat conductivity test equipment.
Description
Technical Field
The invention belongs to the technical field of thermophysical property testing, and particularly relates to a method for testing a heat conductivity coefficient of a cylindrical sample by a punching method.
Background
With the continuous application of power electronic products such as LED lamps and IGBTs, research on materials with high thermal conductivity and low expansion, such as metal matrix composite materials, is increasingly important. Accordingly, characterization and measurement of the thermal conductivity of materials or products is also increasingly important. Currently, a steady-state testing method of a large flat plate is generally adopted for materials with low heat conductivity coefficients, such as ceramics, plastics and the like; for high heat conduction materials, such as metals, a steady state test method of an elongated rod is generally adopted; there are also unsteady state test methods, which are commonly known as hot wire methods and laser flash methods.
The equipment cost of transient test methods such as an unsteady hot wire method and a laser flash method is very high, for example, the equipment of domestic hot wire method is generally about 10 ten thousand, the equipment of imported laser method is generally more than 100 ten thousand, the sample preparation and processing requirements are not high, but the test cost is high, each data point is about 300, the test result of the sample with uneven material is very unstable, and the measurement of the heat conductivity coefficient and the research and development of related products are very unfavorable; the conventional steady-state method has the advantages of simple test equipment, low cost and low test cost, but for materials with high values (such as silver, platinum and the like), the processing of the respective standard samples is only carried out for testing the heat conduction performance, and a large number of experiments are needed; the preparation and processing of metal matrix composites and the like are difficult, and the cost for obtaining standard samples is very high.
Disclosure of Invention
The invention aims to provide a method for testing the heat conductivity coefficient of a cylindrical sample by a punching method, which realizes the test of the heat conductivity coefficient of a small nonstandard cylindrical sample by using common steady-state heat conduction testing equipment.
The invention adopts the following technical scheme: a method for testing the thermal conductivity of a cylindrical sample by a perforation method, the method comprising the steps of: s11, selecting a sample to be detected and A, B reference samples with known different heat conductivity coefficients, and processing the two reference samples into cylinders with equal diameters and heights; the height of each cylinder is not less than 8mm; wherein the expected thermal conductivity range value of the sample to be measured is known; among the two reference samples, one of the reference samples has a thermal conductivity greater than that of the sample to be measured and the other is less than that of the sample to be measured.
S12, radially processing two temperature measuring holes on the side wall of each cylinder, wherein the two temperature measuring holes are arranged at intervals up and down, and the hole spacing is 6-80 mm; each hole depth is equal to or less than the radius of the cylinder.
Step S13, respectively placing each cylinder sample in a test auxiliary device, respectively inserting two thermocouples into two corresponding temperature measuring holes by adopting a flat plate steady state method thermal conductivity tester, respectively measuring and calculating thermal conductivity test values of a sample to be measured and a A, B reference sample, wherein the thermal conductivity test values are respectively: lambda, lambda A And lambda (lambda) B 。
Step S14, estimating the actual heat conductivity coefficient lambda of the sample to be detected by adopting a linear interpolation method from the heat conductivity coefficient test value in step S13 * ；
λ * ＝λ B0 +(λ-λ B )·(λ A0 -λ B0 )/(λ A -λ B ) (1)；
Wherein: lambda (lambda) A0 The true heat conductivity coefficient of the reference sample A; lambda (lambda) B0 Is the true thermal conductivity of the B reference sample.
Further, the method comprises the following steps:
s21, processing a reference material with a known heat conductivity coefficient into a plurality of cylinders with the same diameter and different heights; the height of each cylinder is not less than 8mm;
s22, radially processing two temperature measuring holes on the side wall of each cylinder, wherein the two temperature measuring holes are arranged at intervals up and down, and the hole spacing is 6-80 mm; each hole depth is equal to or less than the radius of the cylinder.
And S23, respectively placing the cylindrical samples in a test auxiliary device, respectively inserting two thermocouples into the corresponding two temperature measuring holes by adopting a flat-plate steady-state thermal conductivity tester, and respectively measuring and calculating the thermal conductivity test value of each corresponding cylinder.
And S24, drawing a data point diagram by taking the hole spacing of each cylinder as an abscissa and the heat conductivity coefficient test value as an ordinate, and fitting a smooth curve to obtain a curve diagram of the heat conductivity coefficient test value of the reference material.
And S25, selecting different reference materials, repeating the steps S21 to S24 respectively to obtain graphs of the thermal conductivity coefficient test values of the reference materials under the diameter, and collecting the graphs of the thermal conductivity coefficient test values of the reference materials to obtain standard graphs of the thermal conductivity coefficients of the different reference materials.
Step S26, repeating the steps S21 to S25 in sequence, wherein different diameter values are selected in the step S21 when the steps are repeated each time; and sequentially obtaining standard patterns of the heat conductivity coefficient test values of the reference materials with different diameters.
Step S27, taking a sample to be measured, wherein the range value of the expected heat conductivity coefficient of the sample to be measured is known, and the range value is positioned between the maximum heat conductivity coefficient test value and the minimum heat conductivity coefficient test value in the standard map under the corresponding diameter;
selecting the corresponding diameter in the standard map as the standard diameter, processing the sample to be measured into a cylinder shape with the standard diameter, repeating the steps S22-S23, and measuring the thermal conductivity coefficient test value lambdac of the sample to be measured; in the standard map, taking the hole spacing of a sample to be detected as an abscissa, taking a heat conductivity coefficient test value as a corresponding ordinate, respectively making a vertical line of each axis through the abscissa, obtaining an intersection point by crossing two straight lines, reading heat conductivity coefficient test values lambda 1 and lambda 2 of reference materials corresponding to two standard curves adjacent to each other above and below the intersection point, simultaneously reading heat conductivity coefficient values lambda 3 and lambda 4 of which the hole spacing is 80mm corresponding to the two standard curves, and estimating the actual heat conductivity coefficient lambda 0 of the sample to be detected according to a formula (3), wherein lambda 0 = lambda 4+ (lambda c-lambda 2) · (lambda 3-lambda 4)/(lambda 1-lambda 2) (2).
Further, the height of each cylinder is slightly higher than 80mm at the highest.
Further, the hole spacing of the two temperature measuring holes is 6 mm-80 mm.
Further, the test auxiliary device comprises a cylindrical heat insulation sleeve with two open ends, two thermocouple jacks are radially arranged on the side wall of the heat insulation sleeve, and the two thermocouple jacks are arranged at intervals up and down and correspond to the positions of the temperature measuring holes; the two ends of the heat insulation sleeve are respectively provided with a circular heat insulation plate, the outer sides of the heat insulation plates are respectively provided with a copper plate closely attached to the heat insulation plates, the copper plates at the upper part are used for heating, and the copper plates at the lower part are used for radiating heat.
The beneficial effects of the invention are as follows: 1. the thermal conductivity of the small nonstandard cylinder sample is tested by using the common steady-state thermal conductivity testing equipment without various expensive novel testing equipment and expensive testing cost, and the requirements of common teaching and scientific research are met.
2. The metal material, the metal matrix composite material or other punchable materials can be tested, and the method can be implemented as long as the heat conductivity coefficient of the sample to be tested is between the highest curve and the lowest curve in the map, or two reference materials respectively lower than and higher than the sample to be tested are found out.
3. The requirements on the diameter and the height of the sample to be tested are reduced, and the sample can be implemented by selecting a proper reference sample material or a proper diameter corresponding to a map according to the requirements of test or actual test working conditions.
4. Once the pattern is established, the test does not need to be repeated, but the curves in the pattern are more compact, and for samples with any hole spacing, the standard pattern can be read and estimated.
5. The difference between the thermal conductivity test value and the true value is very small, typically less than 5%, and especially less than 1% when the hole spacing of the sample is 10mm or 80mm.
Drawings
FIG. 1 is a schematic diagram of the structure of a test specimen and an accessory.
FIG. 2 is a graph of the relationship between the thermal conductivity of red copper, LY12 and 45 steel and the sample hole spacing and fitting curve.
Wherein: 1. a thermal insulation sleeve; 2. thermocouple insertion holes; 3. a heat insulating plate; 4. copper plate. a. And (3) a sample.
Detailed Description
The invention will be described in detail below with reference to the drawings and the detailed description. As shown in fig. 1, reference numeral a designates a sample used.
The invention discloses a method for testing the heat conductivity coefficient of a cylindrical sample by a punching method, which comprises the following steps: s11, selecting two reference samples with known different heat conductivity coefficients of a sample a and a sample A, B to be detected, and processing the two reference samples into cylinders with equal diameters and heights; the height of each cylinder is not less than 8mm. Wherein the expected thermal conductivity range value of the sample to be measured is known; among the two reference samples, one of the reference samples has a thermal conductivity greater than that of the sample to be measured and the other is less than that of the sample to be measured.
S12, radially processing two temperature measuring holes on the side wall of each cylinder, wherein the two temperature measuring holes are arranged at intervals up and down, and the hole spacing is 6-80 mm; each hole depth is equal to or less than the radius of the cylinder.
Step S13, respectively placing each cylindrical sample in a test auxiliary device, respectively adopting a flat-plate steady-state method heat conductivity coefficient tester, respectively inserting two thermocouples into two corresponding temperature measuring holes, heating by the flat-plate steady-state method heat conductivity coefficient tester, respectively measuring and calculating heat conductivity coefficient test values of a sample to be tested and a A, B reference sample, wherein the heat conductivity coefficient test values are respectively: lambda, lambda A And lambda (lambda) B 。
Step S14, adopting linear interpolationIn the step S13, the true thermal conductivity lambda of the sample to be measured is estimated from the thermal conductivity test value * The method comprises the steps of carrying out a first treatment on the surface of the From (lambda-lambda) B )/(λ A -λ B )＝(λ*-λ B0 )/(λ A0 -λ B0 ) Obtaining:
λ * ＝λ B0 +(λ-λ B )·(λ A0 -λ B0 )/(λ A -λ B ) (1)；
wherein: lambda (lambda) A0 The true heat conductivity coefficient of the reference sample A; lambda (lambda) B0 Is the true thermal conductivity of the B reference sample.
The invention also discloses a method for testing the heat conductivity coefficient of the cylindrical sample by using the standard map, which comprises the following steps: s21, processing a reference material with a known heat conductivity coefficient into a plurality of cylinders with the same diameter and different heights; the height of each cylinder is not less than 8mm.
S22, radially processing two temperature measuring holes on the side wall of each cylinder, wherein the two temperature measuring holes are arranged at intervals up and down, and the hole spacing is 6-80 mm; each hole depth is equal to or less than the radius of the cylinder.
And S23, respectively placing the cylindrical samples in a test auxiliary device, respectively adopting a flat-plate steady-state thermal conductivity tester, respectively inserting two thermocouples into the two corresponding temperature measuring holes, heating by the flat-plate steady-state thermal conductivity tester, and respectively measuring and calculating the thermal conductivity test value of each corresponding cylinder.
And S24, drawing a data point diagram by taking the hole spacing of each cylinder as an abscissa and the heat conductivity coefficient test value as an ordinate, and fitting a smooth curve to obtain a curve diagram of the heat conductivity coefficient test value of the reference material.
And S25, selecting different reference materials, repeating the steps S21 to S24 respectively to obtain graphs of the thermal conductivity coefficient test values of the reference materials under the diameter, and collecting the graphs of the thermal conductivity coefficient test values of the reference materials to obtain standard graphs of the thermal conductivity coefficients of the different reference materials.
Step S26, repeating the steps S21 to S25 in sequence, wherein different diameter values are selected in the step S21 when the steps are repeated each time; and sequentially obtaining standard patterns of the heat conductivity coefficient test values of the reference materials with different diameters.
And step S27, taking a sample to be measured, wherein the expected heat conductivity coefficient range value of the sample to be measured is known, and the sample to be measured is positioned between the maximum heat conductivity coefficient test value and the minimum heat conductivity coefficient test value in the standard map under the corresponding diameter.
Selecting the corresponding diameter in the standard map as the standard diameter, processing the sample to be measured into a cylinder shape with the standard diameter, repeating the steps S22-S23, and measuring the thermal conductivity coefficient test value lambdac of the sample to be measured; in the standard map, taking the hole spacing of a sample to be detected as an abscissa, taking a heat conductivity coefficient test value as a corresponding ordinate, respectively making a vertical line of each axis through the abscissa, obtaining an intersection point by crossing two straight lines, reading heat conductivity coefficient test values lambda 1 and lambda 2 of reference materials corresponding to two standard curves adjacent to each other above and below the intersection point, simultaneously reading heat conductivity coefficient values lambda 3 and lambda 4 of which the hole spacing is 80mm corresponding to the two standard curves, and estimating the actual heat conductivity coefficient lambda 0 of the sample to be detected according to a formula (3), wherein lambda 0 = lambda 4+ (lambda c-lambda 2) · (lambda 3-lambda 4)/(lambda 1-lambda 2) (2). The thermal conductivity value at the hole pitch of 80mm was selected because the test value of the thermal conductivity at the hole pitch was substantially equal to the true value, and the hole pitch or a test value greater than the hole pitch was regarded as the true value.
The height of each cylinder is slightly higher than 80mm at most. The hole spacing between the two temperature measuring holes is 6 mm-80 mm.
As shown in fig. 1, the test auxiliary device comprises a cylindrical heat insulation sleeve 1 with two open ends, two thermocouple insertion holes 2 are radially formed in the side wall of the heat insulation sleeve 1, and the two thermocouple insertion holes 2 are vertically arranged at intervals and correspond to the positions of the temperature measuring holes; an annular heat insulation plate 3 is arranged at two ends of the heat insulation sleeve 1, copper plates 4 closely attached to the heat insulation plates 3 are arranged on the outer sides of the heat insulation plates 3, the upper copper plates 4 are used for heating, and the lower copper plates 4 are used for heat dissipation.
At the time of testing, the room temperature at the time of experiment was required to be 25 ℃ and the temperature at the cold end of the thermocouple was required to be 0 ℃. The specific process is as follows:
(1) By swimmingThe calipers and balances measure the geometry and mass of the sample, lower copper plate 4, and the measurements are taken multiple times and then averaged. Wherein the specific heat capacity c= 3.805 ×10 of the copper plate 4 2 ./Kg℃ -1 ；
Measuring the hole pitch h and the radius R of the sample B The average is taken by multiple measurements.
(2) The upper and lower surfaces of the sample are coated with heat-conducting silicone grease, and the sample is placed in a cylindrical heat-insulating sleeve (1) and then placed in the middle of an upper copper plate and a lower copper plate 4.
(3) Will measure T 1 And T 2 The hot ends of the thermocouples are moved down to be respectively inserted into an upper temperature measuring hole and a lower temperature measuring hole of the sample, and the cold ends are both arranged in the ice-water mixture. Wherein, the upper temperature measuring hole and the lower temperature measuring hole are coated with heat conduction silicone grease to ensure good heat conduction
(4) The temperature of the temperature controller is set at 60 ℃, the switch is switched to automatic control, and the temperature can be freely set during experiments.
(5) After 20 to 40 minutes, the time length is different according to the measured materials and the environment, and when V T1 After the reading is stable, i.e. the fluctuation is less than 0.01mV, the temperature indication is read every 2 minutes until V T2 The reading was also relatively stable (fluctuation less than 0.01mV over 0 min.
(6) The thermocouple hot end for measuring the temperature of the lower temperature measuring hole of the sample is moved out and inserted into the lower copper plate, and after the thermocouple hot end is stabilized, the lower copper plate is recorded at the temperature T 3 Corresponding to the temperature potential.
(7) Measuring the steady state value T of the lower copper plate 3 A nearby heat dissipation rate. The method comprises the following specific steps: the sample is removed first, the position of the upper copper plate is adjusted, the upper copper plate is aligned with the lower copper plate, and the lower copper plate is heated after good contact. Lower copper plate temperature ratio T 3 When the temperature is higher than 10 ℃ and the corresponding thermoelectric potential is higher than about 0.39mV, the upper copper plate is removed, all surfaces of the lower copper plate are exposed to air, the lower copper plate is naturally cooled, and temperature indication values are recorded every 30 seconds.
(8) The thermal conductivity of the sample was calculated.
The cooling rate of the copper plate exposed to air on the whole surface is 2 pi R P 2 +2πR P h P Wherein R is P And h P The radius and thickness of the lower copper plate, respectively. However, at steady state heat transfer in the experiment, the area in the upper surface of the copper plate was pi R B 2 Is covered by the sample, since the heat dissipation rate of the objects is proportional to their area, the expression of the copper plate heat dissipation rate should be modified at steady state as:
substituting the above formula into the heat transfer law expression, taking into account ds=pi R B 2 The thermal conductivity can be obtained:
the thermal conductivity of the sample was calculated according to equation 2.11.
In order to verify the method, the metal materials of 45 steel and red copper are used as reference samples, duralumin (LY 12) is used as a test verification sample, cylindrical samples with the diameter of 20mm are respectively processed, a temperature measuring hole is respectively processed at the position 7mm away from the upper end surface and the lower end surface and is used as a hole for inserting a thermocouple for temperature measurement, and the center distance between the two holes is used as the distance between the two temperature measuring surfaces; as shown in fig. 2, the heating component of the thermal conductivity tester is contacted with the copper plate 4 by using the YBF-3 thermal conductivity tester as a testing instrument, so as to realize heating and testing. Results of thermal conductivity measurements of the three samples as a function of hole spacing were tested and calculated as shown in tables 1, 2 and 3.
TABLE 1 relationship between thermal conductivity coefficient of 45 Steel and hole spacing
TABLE 2 relationship between thermal conductivity of "Red copper" and hole spacing
TABLE 3 relationship between "duralumin" thermal conductivity and hole spacing
Data fitting was performed on the data in the above table using origin software to obtain the results shown in fig. 2. Wherein the data points are actual measurement results, the curves are fitting curves, and the fitting curves of red copper, 45 steel and LY12 are respectively:
y c ＝215.61+3.30336x c -0.01507x c 2 (5)；
y s ＝22.79+0.75613x s -0.00525x s 2 (6)；
y l ＝105.20+1.30667x l -0.00482x l 2 (7)；
y and x in formulas (5), (6) and (7) represent the thermal conductivity and the hole spacing, respectively; subscripts c, s and l correspond to three materials of red copper, 45 steel and LY12 respectively;
from the above experimental results, it was found that when the hole spacing of the 45 steel and red copper samples was 80, the curve fitting values were 49.68 and 383.43, respectively, which were already very close to the true values 49 and 390 of the corresponding materials.
The heat conductivity values of 45 steel (indicated by the subscript A) and red copper (indicated by the subscript B) as reference materials and LY12 as verification material were calculated by the formulas (5) and (6) and shown as lambda in Table 4 A And lambda (lambda) B As shown, the result of estimating LY12 from equation 2 is shown as λ in Table 4 * The actual value λ of LY12 is shown 0 190 with lambda 0 -λ * Representing the deviation of the estimated value, using (lambda) 0 -λ * )/λ 0 The error of the estimated value is shown and the result is shown in Table 4.
TABLE 4 duralumin thermal conductivity estimation data and related results
As can be seen from the results in Table 4, the errors of the holes at the current test condition of 7.84mm and 42.1mm are 0.68% and 6.3% respectively, and the errors of the measured values and the true values of the test method provided by the invention are less than 1% when the holes are at about 8mm, so that the test method completely meets the requirements of teaching, scientific research and production.
Claims (3)
1. A method for testing the thermal conductivity of a cylindrical sample by a punching method, comprising the steps of:
s11, selecting a sample to be detected and A, B reference samples with known different heat conductivity coefficients, and processing the two reference samples into cylinders with equal diameters and heights; the height of each cylinder is not less than 8mm;
wherein the expected thermal conductivity range value of the sample to be measured is known; among the two reference samples, one of the reference samples has a thermal conductivity greater than that of the sample to be measured and the other is less than that of the sample to be measured;
s12, radially processing two temperature measuring holes on the side wall of each cylinder, wherein the two temperature measuring holes are formed at intervals up and down, and the hole spacing of the temperature measuring holes is 6-80 mm; the hole depth of each temperature measuring hole is equal to or smaller than the radius of the cylinder;
step S13, respectively adopting a flat-plate steady-state thermal conductivity tester to each cylindrical sample, respectively inserting two thermocouples into two corresponding temperature measuring holes, heating by the flat-plate steady-state thermal conductivity tester, respectively measuring and calculating thermal conductivity test values of the sample to be measured and the A, B reference sample, wherein the thermal conductivity test values are respectively as follows: lambda, lambda A And lambda (lambda) B ；
Step S14, adopting a linear interpolation method, comprisingStep S13, estimating the actual thermal conductivity lambda of the sample to be tested according to the thermal conductivity test value * ；
λ * ＝λ B0 +(λ-λ B )·(λ A0 -λ B0 )/(λ A -λ B ) (1)；
Wherein: lambda (lambda) A0 The true heat conductivity coefficient of the reference sample A; lambda (lambda) B0 Is the true thermal conductivity of the B reference sample.
2. A method for testing the thermal conductivity of a cylindrical sample by using a standard spectrum, which is characterized by comprising the following steps:
s21, processing a reference material with a known heat conductivity coefficient into a plurality of cylinders with the same diameter and different heights; the height of each cylinder is not less than 8mm;
s22, radially processing two temperature measuring holes on the side wall of each cylinder, wherein the two temperature measuring holes are arranged at intervals up and down, and the hole spacing of the temperature measuring holes is 6-80 mm; the hole depth of each temperature measuring hole is equal to or smaller than the radius of the cylinder;
step S23, respectively adopting a flat-plate steady-state thermal conductivity tester to each cylinder sample, respectively inserting two thermocouples into the two corresponding temperature measuring holes, heating by the flat-plate steady-state thermal conductivity tester, and respectively measuring and calculating the thermal conductivity test value of each corresponding cylinder;
step S24, drawing a data point diagram by taking the hole spacing of each cylinder as an abscissa and the heat conductivity coefficient test value as an ordinate, and fitting a smooth curve to obtain a standard curve diagram of the heat conductivity coefficient test value of the reference material;
step S25, selecting different reference materials, and repeating the steps S21 to S24 respectively to obtain standard graphs of the thermal conductivity test values of the reference materials under the diameter, and collecting the standard graphs of the thermal conductivity test values of the reference materials to obtain standard graphs of the thermal conductivity test values of the different reference materials;
step S26, repeating the steps S21 to S25 in sequence, wherein different diameter values are selected in the step S21 when the steps are repeated each time; sequentially obtaining standard patterns of heat conductivity coefficient test values of reference materials with different diameters;
step S27, taking a sample to be detected, wherein the range value of the expected heat conductivity coefficient of the sample to be detected is known, and the sample to be detected is positioned between the maximum heat conductivity coefficient test value and the minimum heat conductivity coefficient test value in the standard map under the corresponding diameter;
selecting the corresponding diameter in the standard map as the standard diameter, processing the sample to be measured into a cylinder shape with the standard diameter, repeating the steps S22-S23, and measuring the thermal conductivity coefficient test value lambdac of the sample to be measured; in the standard map, taking the hole spacing of the sample to be measured as an abscissa, taking a heat conductivity coefficient test value as a corresponding ordinate, respectively making a vertical line of each axis through the abscissa, obtaining an intersection point by crossing two straight lines, reading heat conductivity coefficient test values lambda 1 and lambda 2 of reference materials corresponding to two standard curves adjacent to each other above and below the intersection point, simultaneously reading heat conductivity coefficient lambda 3 and lambda 4 of the hole spacing of 80mm corresponding to the two standard curves, and estimating the actual heat conductivity coefficient lambda 0 of the sample to be measured according to a formula (2), wherein lambda 0 = lambda 4+ (lambda c-lambda 2)/(lambda 3-lambda 4)/(lambda 1-lambda 2) (2).
3. The method for testing the thermal conductivity of the cylindrical sample by using the punching method or the method for testing the thermal conductivity of the cylindrical sample by using the standard map according to claim 1 is characterized in that the testing auxiliary device comprises a cylindrical thermal insulation sleeve (1) with two open ends, two thermocouple jacks (2) are radially arranged on the side wall of the thermal insulation sleeve (1), and the two thermocouple jacks (2) are arranged at intervals up and down and correspond to the positions of the temperature measuring holes; both ends of the heat insulation sleeve (1) are respectively provided with a circular heat insulation plate (3), the outer side of each heat insulation plate (3) is respectively provided with a copper plate (4) closely attached to the heat insulation plate, the copper plate (4) at the upper part is used for heating, and the copper plate (4) at the lower part is used for radiating heat.
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| CN105116008A (en) * | 2015-07-22 | 2015-12-02 | 宁波江东晟利工业产品设计有限公司 | System component based on accomplishing measurement of heat conductivity coefficients of to-be-test samples with different thicknesses |
| CN107764855A (en) * | 2016-08-17 | 2018-03-06 | 比亚迪股份有限公司 | A kind of thermal conductivity measurement method and device |
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