Radial thermal conductivity testing apparatus and method

Abstract

The application provides a radial heat conductivity testing device and testing method for testing radial heat conductivity of a cylindrical sample, which comprises an arc-shaped curved heat conductor and an arc-shaped curved heat sink, the heat conductor and the heat sink are arranged oppositely and do not contact each other, so that a cylindrical accommodating space is formed between the heat conductor and the heat sink, the sample can be placed in the accommodating space, and the outer side surface of the sample can be attached to the inner side surface of the heat conductor and the inner side surface of the heat sink; a heat insulation layer covers the heat conductor and the heat sink; a temperature detection mechanism is used for acquiring the temperature of the heat conductor and the heat sink; and a heating mechanism is in contact with the heat conductor and is used for providing a stable heat source for the heat conductor. The radial heat conductivity testing device has the advantages of simple structure, convenient testing, high testing accuracy and testing efficiency, and can realize nondestructive testing of the cylindrical sample in any direction in the radial direction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal conductivity testing, in particular to a radial thermal conductivity testing device and a radial thermal conductivity testing method. BACKGROUND

[0002] Thermal conductivity, also known as thermal conductivity coefficient, is used to measure the heat conduction capacity of a substance, which refers to the heat transferred per unit time through a unit horizontal cross-sectional area when the temperature gradient is 1℃ / m. The thermal conductivity values of various substances are mainly determined by experiments, and the theoretical estimation is an active topic in modern physics and physical chemistry. In theory, by studying the heat conduction mechanism of the substance based on quantum mechanics and statistical mechanics, a physical model of heat conduction can be established, and the thermal conductivity can be obtained through complex mathematical analysis and calculation. However, due to the limitations of the applicability of the theory, and with the rapid increase of new materials, there is still no sufficiently accurate and widely applicable theoretical equation in the prior art. Therefore, the exploration of thermal conductivity experimental testing methods and techniques is still the main source of thermal conductivity data of substances.

[0003] In the energy industry, the radial thermal conductivity testing method of cylindrical samples has a wide application prospect. When developing geothermal resources, the anisotropy of rock thermal conductivity in different directions needs to be considered, and the core samples are usually obtained by drilling with a drill bit, mainly in the form of a cylinder. In addition, cylindrical lithium batteries usually use spiral electrode assemblies. Due to the existence of a large number of interfaces between the electrodes and the electrolyte layers in the radial conduction path, there is nearly two orders of magnitude difference between the radial and axial thermal conductivities of cylindrical lithium ion batteries. As one of the important thermal physical performance parameters of the battery, the thermal conductivity needs to be tested in different directions for different specifications of the battery, and similar cylindrical industrial products have specific morphological structures. If the battery is mechanically cut, it will cause product failure or damage. The existing technology can test the thermal conductivity of the end face of the cylindrical battery, but cannot test the radial thermal conductivity. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a radial thermal conductivity testing device and a testing method to at least solve the problem that the existing technology can test the thermal conductivity of the end face of the cylindrical battery, but cannot test the radial thermal conductivity.

[0005] To achieve the above purpose, the first aspect of the present application provides a radial thermal conductivity testing device for testing a cylindrical sample, comprising:

[0006] An arc-shaped curved heat conductor and an arc-shaped curved heat radiator are oppositely arranged and not in contact with each other, so that a cylindrical accommodating space is formed between the heat conductor and the heat radiator, and a sample to be measured can be placed in the accommodating space and its outer side can be attached to the inner side of the heat conductor and the inner side of the heat radiator.

[0007] A heat insulation layer covers the heat conductor and the heat radiator.

[0008] A temperature detection mechanism is used to obtain the temperature of the heat conductor and the heat radiator.

[0009] A heating mechanism is in contact with the heat conductor and is used to provide a stable heat source for the heat conductor.

[0010] Optionally, the device further comprises:

[0011] A clamping mechanism is arranged around the heat insulation layer and is used to clamp the heat conductor and the heat radiator by clamping force, so as to clamp the sample to be measured.

[0012] Optionally, the clamping mechanism comprises:

[0013] At least two clamps are spacedly arranged outside the heat insulation layer.

[0014] Optionally, the temperature detection mechanism comprises:

[0015] A first thermometer and a second thermometer, the measuring end of the first thermometer is inserted into the heat insulation layer and is in contact with the outer wall of the heat radiator, and is used to obtain the temperature of the heat radiator; the measuring end of the second thermometer is inserted into the heat insulation layer and is in contact with the outer wall of the heat conductor, and is used to obtain the temperature of the heat conductor.

[0016] Optionally, the temperature detection mechanism comprises:

[0017] A first thermocouple and a second thermocouple, the first thermocouple is in contact with the arc-shaped heat radiator, and is used to obtain the temperature of the arc-shaped heat radiator; the second thermocouple is in contact with the arc-shaped heat conductor, and is used to obtain the temperature of the arc-shaped heat conductor.

[0018] Optionally, the heat conduction end of the heating mechanism is inserted into the heat insulation layer and is in contact with the outer wall of the heat conductor, and is used to provide a stable heat source for the heat conductor.

[0019] Optionally, the heat conductor and the heat radiator have the same shape, and the radial height of the heat conductor and the heat radiator is greater than the radial height of the sample to be measured.

[0020] The second aspect of the present application provides a radial thermal conductivity testing method for testing the radial thermal conductivity of a cylindrical sample to be tested by using the thermal conductivity testing device described above, and the method comprises the following steps:

[0021] obtaining the temperature of the heat conductor, the temperature of the heat sink, the heating power of the heating mechanism, the arc center angle of the heat conductor or the heat sink, and the radial height of the sample to be tested;

[0022] calculating the thermal resistance of the sample to be tested based on the temperature of the heat conductor, the temperature of the heat sink, and the heating power of the heating mechanism;

[0023] calculating the radial thermal conductivity of the sample to be tested based on the thermal resistance of the sample to be tested, the arc center angle of the heat conductor or the heat sink, and the radial height of the sample to be tested.

[0024] Optionally, the thermal resistance of the sample to be tested is calculated by the following formula:

[0025]

[0026] wherein R is the thermal resistance of the sample to be tested, T1 is the temperature of the heat sink, T2 is the temperature of the heat conductor, and P is the heating power of the heating mechanism.

[0027] Optionally, the radial thermal conductivity is calculated by the following formula:

[0028]

[0029] wherein λ is the radial thermal conductivity, α is half of the arc center angle of the heat sink or the heat conductor, K'(α) is the reciprocal of K(α), and dt is the differential of t, t is the integral variable in the integral formula, l is the radial height of the sample to be tested, R is the thermal resistance of the sample to be tested, T1 is the temperature of the heat sink, T2 is the temperature of the heat conductor, and P is the heating power of the heating mechanism.

[0030] The technical scheme of the present application sets the heat conductor and the heat sink to clamp the cylindrical sample to be tested, and sets the heat insulation layer to cover the heat conductor and the heat sink, thereby reducing the influence of the external environment on the temperature transmission process, providing a stable heat source to the heat conductor by the heating mechanism, transmitting the heat from the heat conductor to the heat sink and then to the heat sink through the sample to be tested, and then acquiring the temperatures of the heat conductor and the heat sink by the temperature detection mechanism, so as to calculate the radial thermal conductivity of the cylindrical sample to be tested, which has the advantages of simple structure, convenient testing, high testing accuracy and high testing efficiency, and can realize the lossless testing of the cylindrical sample to be tested in any direction in the radial direction.

[0031] Other features and advantages of the embodiments of the present application will be described in detail in the following specific implementation part. BRIEF DESCRIPTION OF DRAWINGS

[0032] The accompanying drawings are included to provide a further understanding of the embodiments of the application and are incorporated in and constitute a part of the specification, illustrate embodiments of the application and serve to explain the principles of the application, but are not intended to limit the application. In the drawings:

[0033] Figure 1 is a structural schematic diagram of a radial thermal conductivity testing device in a first embodiment provided by the application;

[0034] Figure 2 is a structural schematic diagram of a radial thermal conductivity testing device in a second embodiment provided by the application;

[0035] Figure 3 is a flow chart of a radial thermal conductivity testing method provided by the application.

[0036] Legend of reference signs

[0037] 1 - heat conductor; 2 - heat radiator; 3 - sample to be tested;

[0038] 4 - thermal insulation layer; 5 - temperature detection mechanism; 6 - heating mechanism;

[0039] 7 - clamping mechanism; 51 - first thermometer; 52 - second thermometer

[0040] 53 - first thermocouple; 54 - second thermocouple. DETAILED DESCRIPTION

[0041] The specific embodiments of the application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the application, and are not intended to limit the application.

[0042] Figure 1 is a structural schematic diagram of a radial thermal conductivity testing device in a first embodiment provided by the application.

[0043] As shown in Figure 1 , the embodiment of the application provides a radial thermal conductivity testing device for testing the radial thermal conductivity of a cylindrical sample to be tested, comprising:

[0044] an arc-shaped curved heat conductor 1 and an arc-shaped curved heat radiator 2, the heat conductor 1 and the heat radiator 2 are arranged opposite to each other and do not contact each other, so that a cylindrical accommodating space is formed between the heat conductor 1 and the heat radiator 2, the sample to be tested 3 can be placed in the accommodating space, and the outer side surface thereof can be attached to the inner side surface of the heat conductor 1 and the inner side surface of the heat radiator 2;

[0045] a thermal insulation layer 4 covering the heat conductor 1 and the heat radiator 2;

[0046] A temperature detection mechanism 5 is configured to obtain the temperatures of the heat conductor 1 and the heat radiator 2.

[0047] A heating mechanism 6 is in contact with the heat conductor 1 and is configured to provide a stable heat source for the heat conductor 1.

[0048] Specifically, the existing thermal conductivity test can only test cuboid samples, and the sample needs to be made into a square sample, and then the thermal conductivity of the sample in each direction is measured. When the thermal conductivity of the cuboid sample is tested, only the x, y and z orthogonal directions can be tested. To test other directions, the cuboid sample needs to be re-made, which increases the testing difficulty. Therefore, the present application provides a testing device and method suitable for cylindrical samples.

[0049] More specifically, the radial thermal conductivity testing device is used to test the radial thermal conductivity of the cylindrical sample 3 to be tested, which can be a battery, a rock layer or the like. The arc-shaped curved heat conductor 1 and the arc-shaped curved heat radiator 2 are symmetrically arranged and do not contact each other, so that a cylindrical accommodation space is formed therebetween. When testing, the sample 3 to be tested is placed in the accommodation space between the heat conductor 1 and the heat radiator 2, so that the side surface (convex surface) of the sample 3 to be tested is in contact with the inner side surface (concave surface) of the heat conductor 1 and the heat radiator 2. A heat insulation layer 4 is arranged outside the heat conductor 1 and the heat radiator 2, so that the sample 3 to be tested, the heat conductor 1 and the heat radiator 2 are covered inside the heat insulation layer 4. A heating mechanism 6 is used to provide a stable heat source for the heat conductor 1 to heat the heat conductor 1. The generated heat is transmitted to the heat radiator 2 through the sample 3 to be tested, and then radiated to the external environment through the heat radiator 2. A temperature detection mechanism 5 is used to detect the temperature when the temperature transmission of the heat conductor 1 and the heat radiator 2 is stable, so as to calculate the radial thermal conductivity. The heat insulation layer 4 can avoid the influence of the external environment on the temperature transmission between the sample 3 to be tested, the heat conductor 1 and the heat radiator 2, thereby ensuring the accuracy of the test. The heat conductor 1 and the heat radiator 2 are both metal conductors with an arc-shaped cross section, which are matched with the shape of the sample 3 to be tested, and the temperature transmission of the heat conductor 1 and the heat radiator 2 is uniform, so that the heat conductor 1 and the heat radiator 2 can be in contact with the sample 3 to be tested. The heat insulation layer 4 is a hollow cylindrical structure, which is matched with the heat conductor 1 and the heat radiator 2, and can be made of glass fiber, asbestos, rock wool, aerogel felt, vacuum plate and the like. The constant heating power P of the heating mechanism 6 is 450-550W. When the sample to be tested is a battery-shaped cylindrical electronic device, the excessive temperature of the electronic device can be effectively avoided, and the safety of the test is ensured.

[0050] Further, the device further comprises:

[0051] A clamping mechanism 7 is arranged around the heat insulation layer 4 and is used to clamp the heat conductor 1 and the heat radiator 2 by clamping force, so as to clamp the sample 3 to be tested.

[0052] Specifically, in order to ensure that the heat insulation layer 4 can be closely attached to the heat conductor 1 and the heat sink 2, and the heat conductor 1 and the heat sink 2 can clamp the sample 3 to be tested, a clamping mechanism 7 is arranged outside the heat insulation layer 4 to ensure stable contact and improve test accuracy.

[0053] Further, the clamping mechanism 7 comprises:

[0054] At least two clamps are spaced and sleeved outside the heat insulation layer 4.

[0055] Specifically, the clamping mechanism 7 can adopt at least two clamps which are spaced and sleeved on the heat insulation layer 4, so as to ensure that the heat insulation layer 4 can be closely attached to the heat conductor 1 and the heat sink 2, and the heat conductor 1 and the heat sink 2 can clamp the sample 3 to be tested. The clamps are used for fixing, which is convenient for installation and disassembly, and improves test efficiency.

[0056] Further, the temperature detection mechanism 5 comprises:

[0057] A first thermometer 51 and a second thermometer 52, the measuring end of the first thermometer 51 is inserted into the outer wall of the heat insulation layer 4 and the heat sink 2 to contact, for obtaining the temperature of the heat sink 2; the measuring end of the second thermometer 52 is inserted into the outer wall of the heat insulation layer 4 and the heat conductor 1 to contact, for obtaining the temperature of the heat conductor 1.

[0058] Specifically, when calculating the radial thermal conductivity of the sample 3 to be tested, the temperatures of the heat conductor 1 and the heat sink 2 need to be collected. In this embodiment, the thermometer can be used to obtain the temperatures of the heat conductor 1 and the heat sink 2. When a common thermometer, a digital thermometer or the like is used, a groove can be arranged on the heat conductor 1 and the heat sink 2 to accommodate the temperature sensing end of the thermometer, and the temperature sensing end of the thermometer is located in the groove through the heat insulation layer 4, so as to ensure the accuracy of temperature measurement. An infrared temperature measurement probe can also be used to realize non-contact temperature measurement.

[0059] Further, Figure 2 is a structural schematic diagram of a radial thermal conductivity testing device in a second embodiment provided by the present application, as Figure 2 shown, the temperature detection mechanism comprises:

[0060] A first thermocouple 53 and a second thermocouple 54, the first thermocouple 53 is in contact with the arc-shaped heat sink 2 to obtain the temperature of the arc-shaped heat sink 2, and the second thermocouple 54 is in contact with the arc-shaped heat conductor 1 to obtain the temperature of the arc-shaped heat conductor 1.

[0061] Specifically, the temperature can also be measured by thermocouples, the temperature of the heat conductor 1 is measured by a first thermocouple 53, the temperature of the heat radiator 2 is measured by a second thermocouple 54, and the temperature signal is converted into a thermoelectric power signal, which is converted into the temperature of the measured medium by an electrical instrument (secondary instrument) to realize long-distance transmission and collection. In order to ensure the accuracy of the measurement, the first thermocouple 53 is arranged in the heat conductor 1, and the second thermocouple 54 is arranged in the heat radiator 2.

[0062] Further, the heat conduction end of the heating mechanism 6 is inserted into the outer wall of the heat conductor 1 in contact with the heat insulation layer 4, for providing a stable heat source to the heat conductor 1.

[0063] Specifically, a through hole is arranged on the heat insulation layer 4, and the heating mechanism 6 passes through the heat insulation layer 4 to fully contact with the heat conductor 1, for ensuring stable heat transfer. More specifically, the heating mechanism 6 can adopt a heating wire arranged at intervals on the convex surface of the heat conductor 1, or a high-frequency heating device arranged at intervals on the convex surface of the heat conductor 1, adopts the magnetic field induction eddy current heating principle, uses the magnetic field generated by the current passing through the coil, when the magnetic force line in the magnetic field passes through the heat conductor 1, makes the heat conductor 1 itself heat at high speed, and can reach the preset temperature value in a short time.

[0064] Further, the heat conductor 1 and the heat radiator 2 are of the same shape, and the radial height of the heat conductor 1 and the heat radiator 2 is greater than the radial height of the sample 3 to be measured.

[0065] Specifically, in order to ensure stable heat transfer, the heat conductor 1 and the heat radiator 2 are arranged in the same shape, and the radial height of the heat conductor 1 and the heat radiator 2 is greater than the height of the sample 3 to be measured, so that the sample 3 to be measured is completely in the space formed by the heat conductor 1 and the heat radiator 2, to reduce the influence of the external environment on the temperature transmission process. The size of the heat conductor 1 and the heat radiator 2 is determined by the size of the sample 3 to be measured. One size (diameter) of the sample 3 to be measured corresponds to a set of heat conductor 1 and heat radiator 2.

[0066] Figure 3 is a flow chart of the radial thermal conductivity testing method provided by the present application, as shown in Figure 3 The present application provides a radial thermal conductivity testing method for testing the radial thermal conductivity of a cylindrical sample by using the above-mentioned thermal conductivity testing device, which comprises the following steps:

[0067] Step 101, obtaining the temperature of the heat conductor, the temperature of the heat radiator, the heating power of the heating mechanism, the angle of the arc center of the heat conductor or the heat radiator, and the radial height of the sample to be measured of the radial thermal conductivity testing device;

[0068] Step 102, based on the temperature of the heat conductor, the temperature of the heat sink and the heating power of the heating mechanism, the thermal resistance of the sample to be measured is calculated;

[0069] Step 103, based on the thermal resistance of the sample to be measured, the arc center angle of the heat sink or the heat conductor and the radial height of the sample to be measured, the radial thermal conductivity of the sample to be measured is calculated.

[0070] Specifically, before the radial thermal conductivity test is performed, the arc center angle of the heat conductor or the heat sink is obtained; the radial height of the sample to be measured is measured; the cylindrical sample is placed in a specific area of the test device, and then the heat conductor of the test device is attached to one side of the surface of the cylindrical sample, so that the arc center angle of the heat conductor passes through the cross-sectional center of the cylindrical sample, and the heat sink is attached to the other side of the surface of the cylindrical sample; the heat insulation sleeve is arranged on the circumferential surface of the heat conductor and the heat sink, so that heat enters the cylindrical sample to be measured from the heat conductor and heat is dissipated to the outside from the heat sink; after installation, the heating mechanism is operated to provide heat to the cylindrical sample through the heat conductor at a constant power; the temperature T2 of the heat conductor is obtained by the heating mechanism, and the temperature T1 of the heat sink is obtained by the heating mechanism; based on the temperature of the heat conductor, the temperature of the heat sink and the heating power of the heating mechanism, the thermal resistance of the sample to be measured is calculated; based on the thermal resistance of the sample to be measured, the arc center angle of the heat sink or the heat conductor and the radial height of the sample to be measured, the radial thermal conductivity of the sample to be measured is calculated.

[0071] Further, the thermal resistance of the sample to be measured is calculated by the following formula:

[0072]

[0073] Wherein, R is the thermal resistance of the sample to be measured; T1 is the temperature of the heat sink; T2 is the temperature of the heat conductor; P is the heating power of the heating mechanism.

[0074] The heating mechanism can use an electric heater, and the constant power is

[0075] Wherein, U is the voltage loaded on the resistance wire, R is the resistance value of the resistance wire, and P is the constant power.

[0076] Further, the radial thermal conductivity is calculated by the following formula:

[0077]

[0078] Wherein, λ is the radial thermal conductivity; α is half of the arc center angle of the heat sink or the heat conductor; K(α)' is the reciprocal of K(α), and dt is the differential of t, t is the integral variable in the integral formula; l is the radial height of the sample to be measured; R is the thermal resistance of the sample to be measured; T1 is the temperature of the heat sink; T2 is the temperature of the heat conductor; P is the heating power of the heating mechanism.

[0079] Specifically, generally, the thermal conductivity in heat transfer is generally obtained by the following formula:

[0080]

[0081] Wherein, k is the thermal conductivity, Q is the heat, t is the time, L is the length, A is the area, and T is the temperature difference.

[0082] The prerequisite for using this formula is that the two end faces of the heat conduction through the object must be parallel and equal-area planes. The difficulty to be solved by the present application is that the two ends of the sample to be measured are curved surfaces, not planes, and there is a lack of ready-made technical method for radial thermal conductivity testing in the field of heat transfer and thermodynamic engineering.

[0083] The derivation process of the radial thermal conductivity calculation formula proposed in the technical solution is as follows:

[0084] The partial differential equation form of heat conduction satisfies:

[0085]

[0086] Wherein, Delta is the Laplace operator of the spatial variable, u=u(t,x,y,z) represents that the temperature is a function of the time variable t and the spatial variable (x,y,z), Indicates the rate of change of the temperature of a point in space with respect to time.

[0087] The Laplace operator, also known as the Laplace operator, is a second-order differential operator defined in Euclidean space, defined as the divergence of the gradient.

[0088] Since the present application discusses the steady state, therefore,

[0089] Therefore, the form of the steady-state heat conduction equation is Obviously, this equation belongs to the Laplace equation and satisfies the Cauchy-Riemann condition.

[0090] The Cauchy-Riemann condition, also known as the Cauchy-Riemann condition, provides two partial differential equations that are necessary and sufficient conditions for a differentiable function to be a holomorphic function in an open set.

[0091] According to the potential function theory, due to the symmetry of the heat flow field, 1 / 4 circle can be studied according to the top view;

[0092] represents that the located boundary belongs to a closed boundary, and represents that the located boundary is a normal axis of a straight line boundary or a curved boundary.

[0093] The steady heat conduction equation satisfies the Cauchy-Riemann condition, and thus the region of the (x, y) axis can be projected into the coordinates of (rcosθ, rsinθ) by using the conformal transformation W = lni / z, to obtain:

[0094] e-u = r and e-iv = ie-iθ, wherein 0 < r < +∞, and 0 ≤ θ ≤ π / 2.

[0095] The plane is converted into a flow field problem by using the conformal transformation W = lni / z:

[0096]

[0097] According to the Schwarz-Christoffel mapping, a calculation formula of the radial heat conductivity is obtained:

[0098]

[0099] wherein λ is the radial heat conductivity; α is a half of the inscribed angle supplement of the arc center angle of the heat sink or the heat conductor, that is, K(alpha)' is the reciprocal of K(alpha), and dt is the differential of t, t is an integral variable in the integral formula; l is the radial height of the sample to be measured; R is the thermal resistance of the sample to be measured; T1 is the temperature of the heat sink; T2 is the temperature of the heat conductor; and P is the heating power of the heating mechanism.

[0100] The Schwarz-Christoffel mapping is a mapping of a half plane bivalued conformal mapping into a polygonal region, and the Christoffel-Schwarz formula is an expression of a conformal mapping function of the polygonal region.

[0101] The embodiment of the present application further provides a radial heat conductivity calculation device, comprising:

[0102] An acquisition module acquires the temperature of the heat conductor, the temperature of the heat sink, the heating power of the heating mechanism, the arc center angle of the heat conductor or the heat sink, and the radial height of the sample to be measured of the radial heat conductivity testing device;

[0103] A first calculation module calculates the thermal resistance of the sample to be measured based on the temperature of the heat conductor, the temperature of the heat sink and the heating power of the heating mechanism;

[0104] The second calculation module calculates a radial heat conductivity of the sample to be measured based on a thermal resistance of the sample to be measured, an arc center angle of the heat sink or the heat conductor, and a radial height of the sample to be measured.

[0105] Further, the thermal resistance of the sample to be measured is calculated by the following formula:

[0106]

[0107] wherein R is the thermal resistance of the sample to be measured, T1 is the temperature of the heat sink, T2 is the temperature of the heat conductor, and P is the heating power of the heating mechanism.

[0108] Further, the radial heat conductivity is calculated by the following formula:

[0109]

[0110] wherein λ is the radial heat conductivity, α is half of the arc center angle of the heat sink or the heat conductor, K'(α) is the reciprocal of K(α), and dt is the differential of t, t is the integral variable in the integral formula, l is the radial height of the sample to be measured, R is the thermal resistance of the sample to be measured, T1 is the temperature of the heat sink, T2 is the temperature of the heat conductor, and P is the heating power of the heating mechanism.

[0111] The embodiment of the present application also provides a machine readable storage medium, which stores instructions for causing a machine to execute the radial heat conductivity testing method described above.

[0112] Those skilled in the art can understand that all or part of the steps of the method described above can be completed by programs instructing relevant hardware, and the programs are stored in a storage medium, including a plurality of instructions for causing a single-chip microcomputer, a chip or a processor to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media capable of storing program codes.

[0113] The optional embodiments of the present application are described in detail above in combination with the drawings, but the embodiments of the present application are not limited to the specific details in the above-described embodiments. Within the technical concept scope of the embodiments of the present application, various simple modifications can be made to the technical solutions of the embodiments of the present application, and these simple modifications all belong to the protection scope of the embodiments of the present application. In addition, it should be noted that, in the above-described specific embodiments, various specific technical features described in the embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, various possible combinations are not described again in the embodiments of the present application.

[0114] In addition, any combination of various different embodiments of the present application can also be made, as long as it does not deviate from the idea of the embodiments of the present application, and it should also be considered as disclosed by the embodiments of the present application.

Claims

1. A method for testing radial thermal conductivity, used in a radial thermal conductivity testing device to test the radial thermal conductivity of a cylindrical sample, characterized in that, The radial thermal conductivity testing device includes: The system comprises an arc-shaped curved surface heat conductor (1) and an arc-shaped curved surface heat sink (2), wherein the arc-shaped curved surface heat conductor (1) and the arc-shaped curved surface heat sink (2) are arranged opposite to each other and do not contact each other, so that a cylindrical accommodating space is formed between them, and the sample to be tested (3) can be placed in the accommodating space, and its outer surface can be in contact with the inner surface of the arc-shaped curved surface heat conductor (1) and the inner surface of the arc-shaped curved surface heat sink (2); a heat insulation layer (4) covering the arc-shaped curved surface heat conductor (1) and the arc-shaped curved surface heat sink (2); a temperature detection mechanism (5) for obtaining the temperature of the arc-shaped curved surface heat conductor (1) and the arc-shaped curved surface heat sink (2); and a heating mechanism (6) in contact with the arc-shaped curved surface heat conductor (1) for providing a stable heat source to the arc-shaped curved surface heat conductor (1). The testing method includes: The temperature of the arc-shaped curved surface heat conductor, the temperature of the arc-shaped curved surface heat sink, the heating power of the heating mechanism, the arc center angle of the arc-shaped curved surface heat conductor or the arc-shaped curved surface heat sink, and the radial height of the sample to be tested are obtained from the radial thermal conductivity testing device. The thermal resistance of the sample under test is calculated based on the temperature of the curved surface heat conductor, the temperature of the curved surface heat sink, and the heating power of the heating mechanism. Based on the thermal resistance of the sample under test, the arc-shaped heat sink or arc-shaped heat conductor's central angle, and the radial height of the sample under test, the radial thermal conductivity of the sample under test is calculated using the following formula: ； in, Radial thermal conductivity; It is half of the supplementary angle of the central arc of the arc-shaped heat sink or arc-shaped heat conductor; for The reciprocal of, and ; for The differential, is the integration variable in the integral expression; The radial height of the sample to be tested; The thermal resistance of the sample to be tested; The temperature of the curved surface heat sink; The temperature of the arc-shaped curved surface heat conductor; This refers to the heating power of the heating mechanism.

2. The radial thermal conductivity testing method according to claim 1, characterized in that, The device further includes: A clamping mechanism (7) is provided around the heat insulation layer (4) and is used to clamp the arc-shaped curved heat conductor (1) and the arc-shaped curved heat sink (2) by clamping force, thereby clamping the sample to be tested (3).

3. The radial thermal conductivity testing method according to claim 2, characterized in that, The clamping mechanism (7) includes: At least two clamps are spaced apart and fitted over the insulation layer (4).

4. The radial thermal conductivity testing method according to claim 1, characterized in that, The temperature detection mechanism (5) includes: A first thermometer (51) and a second thermometer (52) are used to obtain the temperature of the arc-shaped surface heat sink (2). The measuring end of the first thermometer (51) is inserted through the heat insulation layer (4) and contacts the outer wall of the arc-shaped surface heat sink (2). The measuring end of the second thermometer (52) is inserted through the heat insulation layer (4) and contacts the outer wall of the arc-shaped surface heat conductor (1).

5. The radial thermal conductivity testing method according to claim 1, characterized in that, The temperature detection mechanism includes: A first thermocouple (53) and a second thermocouple (54) are present. The first thermocouple (53) is in contact with the arc-shaped surface heat sink (2) to obtain the temperature of the arc-shaped surface heat sink (2). The second thermocouple (54) is in contact with the arc-shaped surface heat conductor (1) to obtain the temperature of the arc-shaped surface heat conductor (1).

6. The radial thermal conductivity testing method according to claim 1, characterized in that, The heat conduction end of the heating mechanism (6) is inserted through the heat insulation layer (4) and contacts the outer wall of the arc-shaped curved heat conductor (1) to provide a stable heat source to the arc-shaped curved heat conductor (1).

7. The radial thermal conductivity testing method according to claim 1, characterized in that, The arc-shaped heat conductor (1) and the arc-shaped heat sink (2) have the same shape, and the radial height of the arc-shaped heat conductor (1) and the arc-shaped heat sink (2) is set to be greater than the radial height of the sample to be tested (3).

8. The radial thermal conductivity testing method according to claim 1, characterized in that, The thermal resistance of the sample to be tested is calculated using the following formula: ； in, The thermal resistance of the sample to be tested; The temperature of the curved surface heat sink; The temperature of the arc-shaped curved surface heat conductor; This refers to the heating power of the heating mechanism.

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