Device for measuring thermophysical parameters of metal in open environment

Abstract

The utility model belongs to the technical field of physical parameter measuring devices, and relates to a metal thermophysical parameter measuring method and device. In a traditional experimental device, four thermophysical parameters including the heat conductivity coefficient, the specific heat capacity, the convective heat transfer coefficient and the emissivity are achieved through different measuring devices, measurement of the heat conductivity coefficient is generally achieved through a one-dimensional heat transfer model, and the device is complex in structure. The device comprises a heating system and a temperature measuring system, the bottom end of a to-be-measured sample is arranged on a heat insulation plate, the periphery and the top end of the to-be-measured sample are exposed in an open space, and a heat transfer model is expanded from one dimension to three dimensions. Heating is stopped after the sample is continuously heated, the sample is subjected to three temperature change processes of temperature rise, steady state and temperature reduction, and the temperature measurement system measures the temperatures of different positions of the sample. By analyzing the influence of conduction, convection and radiation in different temperature stages on heat transfer, the four thermophysical parameters are measured in the same experimental device. The device is simple in structure, rich in experiment content, advanced in experiment method and suitable for carrying out teaching experiments in laboratories.

Description

Technical Field

[0001] The utility model belongs to the technical field of physical parameter measurement devices, and particularly relates to a method and device for measuring the thermal physical properties of metals. Background Technique

[0002] The thermal physical properties of materials refer to the properties related to heat among various properties of an object. Relatively common thermal physical parameters include: the thermal conductivity characterizing the heat conduction ability, the specific heat capacity characterizing the heat storage ability, and the convective heat transfer coefficient and emissivity characterizing the heat dissipation ability, etc. The measurement of thermal physical parameters is one of the important thermal experiments in the college physics experiment course.

[0003] At present, in the college physics experiment teaching of major universities, various thermal physical parameters are basically realized by different measurement devices. For example, to measure the thermal conductivity of a good conductor, there are the steady-state method based on Fourier's law of heat conduction and the non-steady-state method of measuring the change of temperature inside the material with time. In both methods, a cooling device needs to be added at one end of the sample to maintain a constant temperature difference at both ends of the sample, and both study one-dimensional heat conduction. Generally, heat insulation materials are added outside the device to minimize the generation of heat convection and heat radiation as much as possible. The device structure is complex and the measurement function is single. According to different measurement principles, there are a specific heat coefficient tester using the cooling method and a specific heat coefficient tester using the mixing calorimetry method for the specific heat capacity. For the convective heat transfer coefficient and emissivity, due to being greatly affected by experimental conditions and environmental factors, such experiments are rarely carried out in experimental teaching.

[0004] In recent years, China's scientific and technological level has developed rapidly, and the temperature measurement technology and data processing means have been continuously improved, providing the feasibility for us to achieve accurate temperature measurement and process complex data. However, in the experimental teaching of major universities, the measurement methods of thermal physical parameters still use traditional measurement devices, which cannot meet the needs of cultivating high-quality talents adapted to the development of the times.

[0005] The present invention removes the insulating material and the cooling device at one end in the traditional experimental device, simplifies the experimental device, exposes the sample to the natural environment, and realizes the measurement of four thermal physical parameters, namely, the thermal conductivity, emissivity, convective heat transfer coefficient, and specific heat capacity. The experimental content is more abundant, enabling students to better understand the heat transfer and temperature change inside the substance, and deepening students' understanding and mastery of the three ways of heat transfer through experiments. Summary of the Invention

[0006] The utility model solves its technical problems by adopting the following technical solutions:

[0007] Metal thermal property parameter measurement device in an open environment, including a heating system and a temperature measurement system; the heating system includes a voltage regulator, a heating rod, a heat insulation plate, and a control circuit module. The heating rod is placed in the reserved hole at the bottom of the sample to be measured, the bottom of the sample to be measured is placed on the heat insulation plate, and the surrounding and top are exposed to the open space. The voltage regulator, the heating rod, and the control circuit module are electrically connected. The control circuit module controls the on-off of the voltage regulator, and the voltage regulator is electrically connected to the heating rod to heat the sample to be measured by the steady-state method; the voltage regulator and the heating rod are periodically electrically connected to heat the sample to be measured by the dynamic method in the periodic mode; the sample to be measured continuously heats up after continuous heating until the temperature reaches a steady state and then stops heating, and the sample naturally cools to room temperature. The sample undergoes three temperature change processes of heating up, steady state, and cooling down. The temperature measurement system measures the temperature at different positions of the sample, and by analyzing the influence of conduction, convection, and radiation on heat transfer in different temperature stages, the measurement of thermal conductivity, specific heat capacity, convective heat transfer coefficient, and emissivity is realized.

[0008] Further, the sample to be measured is a slender cylinder.

[0009] Further, the size of the reserved hole at the bottom of the sample to be measured is the same as that of the heating rod.

[0010] Further, the sample to be measured is a material with a relatively high thermal conductivity such as metal.

[0011] Further, holes are drilled axially in the sample to be measured, and the hole depth reaches the center position of the sample. The K-type thermocouple measures the temperature at the center position of the sample.

[0012] Further, the heat insulation plate has holes, and the power cord of the heating rod passes through the heat insulation plate and is electrically connected to the voltage regulator and the control circuit.

[0013] Further, the heat insulation plate is made of aluminosilicate ceramic fiber board with a relatively high heat insulation coefficient.

[0014] Further, the voltage regulation range of the voltage regulator is 0V - 220V, providing different heating powers for the heating rod.

[0015] Further, the control circuit module includes a single-chip microcomputer and a power relay.

[0016] Further, the temperature measurement system includes a single-chip microcomputer, a K-type thermocouple, a temperature conversion chip, and a display screen.

[0017] The advantages and positive effects of the present utility model are:

[0018] 1. The present utility model removes the heat insulation material wrapped around the sample to be measured and the end cooling device in the traditional experimental device, and the heat transfer model is extended from one-dimensional to three-dimensional. It is based on the natural heat dissipation process in the natural environment, which helps students better understand the physical process of heat transfer.

[0019] 2. It can simultaneously measure four thermal property parameters, namely thermal conductivity, emissivity, convective heat transfer coefficient, and specific heat capacity, overcoming the problem of single physical parameter measurement in traditional experimental teaching instruments.

[0020] 3. It can implement the measurement of the thermal properties of metals by the steady-state method and the dynamic method of periodic heating, with richer experimental contents.

[0021] 4. By changing the heating power, the thermal properties of metals at different temperatures can be explored.

[0022] 5. Through repeated experiments, the measurement errors of specific heat capacity and thermal conductivity are both about 5%, and the convective heat transfer coefficient and emissivity are within the reference value range, with high accuracy and stability.

[0023] 6. It has a simple structure, low cost, low requirements for experimental environmental conditions, simple operation, and the experimental principle helps students understand the mathematical methods in physics, and is suitable for carrying out teaching experiments in the laboratory. Description of the Drawings

[0024] The technical solutions of the present utility model will be further described in detail below in conjunction with the drawings and embodiments. However, it should be noted that these drawings are only designed for the purpose of explanation and therefore are not used to limit the scope of the present utility model. In addition, unless otherwise specified, these drawings are only intended to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0025] Figure 1 It is a schematic structural diagram of the device for measuring thermal property parameters in an open environment provided in Embodiment 1 of the present utility model;

[0026] Figure 2 It is a schematic diagram showing the change of the average temperature of the sample with time under steady-state heating provided in Embodiment 2 of the present utility model;

[0027] Figure 3 It is a schematic diagram of the heat flow of the sample provided in Embodiment 2 of the present utility model;

[0028] Figure 4 It is a schematic diagram showing the change of the average temperature of the sample with time under dynamic heating provided in Embodiment 3 of the present utility model. Detailed Embodiments

[0029] First of all, it should be noted that the following will specifically illustrate the specific structure, characteristics, advantages, etc. of the present utility model by way of examples. However, all the descriptions are only for illustration and should not be construed as any limitation to the present utility model. In addition, any single technical feature described or implied in each of the embodiments mentioned in this article, or any single technical feature shown or implied in each of the drawings, can still be arbitrarily combined or deleted between these technical features (or their equivalents), so as to obtain more other embodiments of the present utility model that may not be directly mentioned in this article. Additionally, for the sake of simplifying the drawings, the same or similar technical features may only be labeled in one place in the same drawing.

[0030] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0031] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other.

[0032] Embodiment 1

[0033] As Figure 1 , the metal thermal property parameter measurement device in an open environment provided in this embodiment includes a heating system and a temperature measurement system. The heating system includes a voltage regulator T, a heating rod R, an adiabatic plate J, and a control circuit module M. The heating rod R is placed in the reserved hole at the bottom of the sample to be measured Y, and the bottom surface of the heating rod R is flush with the bottom surface of the sample to be measured Y. It is placed on the adiabatic plate J. The power supply wire of the heating rod passes through the reserved hole of the adiabatic plate J and is electrically connected to the voltage regulator T and the power relay Z. The control circuit module M controls the on and off time of the power relay Z to achieve heating by the steady-state method or the dynamic method. The temperature measurement system measures the thermal conductivity, specific heat capacity, convective heat transfer coefficient, and emissivity by measuring the temperatures at different positions of the sample to be measured.

[0034] The control circuit module M includes a single-chip microcomputer, a level isolation and conversion circuit, and a power relay Z. The single-chip microcomputer outputs a level signal, which, after level conversion and isolation, controls the power relay Z. The pins 2 and 3 of the power relay Z are connected, and the voltage regulator T is electrically connected to the heating rod R to heat the sample to be tested by the steady-state method. The single-chip microcomputer outputs a periodic level signal, which, after level conversion and isolation, controls the power relay Z. The pins 2 and 3 of the power relay Z are periodically connected, and the voltage regulator T is periodically electrically connected to the heating rod R to heat the sample by the dynamic method. By changing the output level period of the single-chip microcomputer, the sample can be heated by the dynamic method under different cycle modes. The single-chip microcomputer can use STM32 series chips, the level conversion can use S8050 triodes, the level isolation can use TLP-521 chips, and the power relay can use 9431C12DS chips.

[0035] The temperature measurement system C includes a single-chip microcomputer, 8-channel K-type thermocouples, a temperature conversion module, and a display screen. 7-channel K-type thermocouples are respectively placed in the temperature measurement holes of the sample to be tested. The K-type thermocouples are electrically connected to the temperature conversion module. The temperature conversion chip is electrically connected to the I / O port of the single-chip microcomputer, and the single-chip microcomputer is electrically connected to the display screen. The K-type thermocouples collect the temperatures at different positions of the sample to be tested, which are input into the single-chip microcomputer for processing through the temperature conversion module and then displayed on the liquid crystal screen. 1-channel K-type thermocouple measures the ambient temperature. The single-chip microcomputer can use STM32 series chips, and the core device of the temperature conversion module uses MAX6675.

[0036] The voltage regulation range of the voltage regulator T is 0V - 220V, which provides different heating powers for the heating rod R. For experimental safety considerations, the heating power is not greater than 50W. The heat insulation board J uses a high-temperature-resistant aluminum silicate ceramic fiber board with a high heat insulation coefficient. The sample to be tested Y is a material with a high thermal conductivity such as metal.

[0037] In the present invention, the shape of the sample is a slender cylindrical shape. The radial temperature field of the sample is ignored. The diameter of the sample should be as small as possible. The length of the sample determines the heating time. If the length is too long, not only the heating time increases, but at the end of the sample, the temperature change tends to be gentle and the temperature gradient is not obvious. The sample to be tested is measured for temperature at equal intervals axially. The distance between the temperature measurement holes can reflect the axial temperature gradient of the sample. The temperature measurement accuracy of the K-type thermocouple is ±0.8°C. For too dense temperature measurement holes, due to the existence of measurement errors, the temperature gradient may not be obvious, which adds interference to data processing. At the same time, dense temperature measurement holes require more K-type thermocouples, which will increase the instrument cost. Considering the above factors, the sample length is 245cm, the diameter is 2cm, the axial temperature measurement interval is 3.5cm, the temperature measurement holes are deep to the axial center line of the sample, and the temperature of the central axis of the sample is measured.

[0038] When one end of the sample is heated, according to the law of conservation of energy and Fourier's law of heat conduction, the heat conduction differential equation of the sample is listed:

[0039]

[0040] After continuous heating, the temperature of the sample to be measured will continue to rise until it reaches a steady state and then the heating stops, and it cools naturally to room temperature. The sample experiences three temperature change processes: heating up, steady state, and cooling down. The three terms on the right side of Equation (1) represent three destinations of the heat source respectively. From left to right, the first term represents the storage of heat in the sample, the second term represents the heat transfer by convection from the metal surface to the surrounding air, and the third term represents the heat radiation from the surface to the surrounding environment.

[0041] At different temperature stages of the sample, the proportions of these three terms are different: at the initial stage of heating up, the temperature is relatively low, and the proportions of the latter two terms are relatively small, and the conduction and storage of heat in the sample dominate. In the middle and late stages of heating up, as the temperature gradually rises, the proportions of the three terms gradually become average. During the steady-state heating process, the heat conduction in the sample reaches a steady state, and the heat mainly flows out in the form of heat convection conduction and heat radiation in the air, and the latter two terms dominate. At the initial stage of the cooling process, the temperature is relatively high, and the form of heat outflow is similar to that in the steady state; while in the middle and late stages of the cooling process, the temperature is relatively low, and the heat mainly flows out in the form of heat convection in the air, with the second term dominating.

[0042] Whether to consider the term of temperature changing with time in Equation (1) corresponds to the dynamic method and the steady-state method in the measurement method of thermal conductivity.

[0043] Example 2

[0044] The device for measuring the thermal physical properties of metals in an open environment provided in this example is a further improvement and supplement to Example 1:

[0045] Measuring the thermal conductivity of metals by the steady-state method: Continuously heat the sample to be measured, and the curve of the average temperature of the sample changing with time is as Figure 2 shown. Considering the heating-up stage of the sample, Figure 2 the part in Region 1 in

[0046] Q = CmΔT (2)

[0047] where m is the mass of the sample; ΔT is the change in the average temperature of the sample. Differentiate both sides of Equation (2) with respect to time:

[0048]

[0049] In Equation (3), is the output power P0 of the heat source; is Figure 2 the slope k1 of the curve of the temperature changing with time in the part of Region 1 in

[0050] P0 = Cmk1 (4)

[0051] The heat dissipation from the sample surface is not considered in Equation (4). Considering Figure 2 the change in the temperature state of part of the sample in Region 3 in

[0052] During the cooling process, the heat stored in the sample is mainly dissipated in the forms of air heat convection and metal heat radiation. At this time, there is:

[0053]

[0054] where P α is the heat dissipated through heat convection per unit time, and P β is the heat dissipated through heat radiation per unit time.

[0055] P α = Sα(T - T0) (6)

[0056] S is the contact area between the sample and the air.

[0057] For the sample to be measured, the heat dissipation efficiency P loss is:

[0058]

[0059] When approaching room temperature, i.e., T ≈ T0, Equation (7) is expanded by Taylor series:

[0060]

[0061] When the proportion of the first-order term is more than 90% of the total:

[0062]

[0063] The higher-order terms can be ignored, and only the first-order term is retained:

[0064]

[0065] P loss ′ is the heat dissipation power that ignores the second-order infinitesimal of metal heat radiation. Equation (5) is transformed into:

[0066]

[0067] The solution of this equation is:

[0068] T - T0 = Ce -Bt (13)

[0069] where

[0070]

[0071] Therefore, the slope of ln(T - T0) with respect to time t is equal to -B:

[0072]

[0073] According to Equation (10), the temperature range that satisfies the condition of neglecting higher-order terms can be calculated using the theoretical values of α and β, that is Figure 2 Region 3, the slope is obtained by fitting the straight line:

[0074]

[0075] From Equation (15), k2·Cm(T - T0) is the sum of the first-order terms of the convective and radiative heat dissipation of the sample to be measured, which is approximately the total heat dissipation power of the sample.

[0076] The calculation of specific heat capacity considers Figure 2 In part of Region 1, the heating process is linear, and the heat dissipation power also changes approximately linearly with temperature. The higher-order terms of heat dissipation can be ignored. The average value of the temperature range is selected and represented by The average heat dissipation power during this process is The thermodynamic equation for the metal heating process can be written as:

[0077]

[0078] The calculation formula for specific heat capacity is obtained:

[0079]

[0080] The convective heat transfer coefficient α of air and the emissivity β of the metal change with temperature. When processing data, only the magnitudes of the two parameters when the sample reaches the steady-state temperature can be calculated. At steady state, the heat input by the heating rod is lost in the form of heat dissipation of the sample, that is P0 = P loss , then:

[0081]

[0082] T max is the average temperature of the sample at steady state. Through Equation (19), β can be calculated:

[0083]

[0084] Substitute β into Equation (15) to calculate α:

[0085]

[0086] Consider Figure 2 the steady-state process in Region 2. The temperature field of the sample no longer changes with time. According to Fourier's law, the heat flux density through a certain cross-section of the sample is:

[0087]

[0088] The magnitude of the heat flux through a certain cross-section of the sample is equal to the heating power minus the heat flux dissipated radially from the first half of the sample before this cross-section. As Figure 3 shown, P0 is the heat flux input to the sample. The heat flux flows along the sample towards the low-temperature section. At the same time, the heat flux will also be lost in the form of air heat convection and thermal radiation along the radial direction. The lost power is represented by P1, and the magnitude of the heat flux finally reaching the cross-section and passing through the cross-section is represented by P2. According to the law of conservation of energy, the heat flux through the cross-section is:

[0089] P2 = P0 - P1 (23)

[0090] Figure 3 In (23), select the cross-section Q between the temperature measurement points T2 and T3 as the reference cross-section. Then the heat flux dissipated before the heat flux enters the reference cross-section is:

[0091]

[0092] Use the temperatures of the temperature measurement points T1 and T2 to represent the average temperatures in the areas S1 and S2 of the sample in contact with the air respectively. Use the temperature gradients on the cross-section calculated from the temperatures of the temperature measurement points at both ends of the cross-section. From Equation (22), the thermal conductivity can be obtained as:

[0093]

[0094] where δL is the length interval between two adjacent temperature measurement points, and A is the cross-sectional area of the sample.

[0095] Example 3

[0096] The metal thermal property parameter measurement device provided in this example is a further improvement and supplement to Example 1:

[0097] Under the consideration of heat dissipation, apply a periodic heat source to the sample:

[0098] T(t) = T s + T n sin(ωt) (26)

[0099] That is, the temperature of the heat source periodically varies with a frequency ω within the range of ±T s near T n .

[0100] Without considering the radial temperature distribution of the sample and the heat dissipation at the end faces, Equation (1) can be expressed as:

[0101]

[0102] It can be further simplified to:

[0103]

[0104] After heating for a period of time, the temperature distribution in the sample is obtained from Equation (28):

[0105]

[0106] M is the term related to thermal conductivity and is regarded as a constant. It can be seen from Equation (29) that the periodic heat source makes the temperature field in the sample have a distribution of thermal waves with an exponentially decaying amplitude along the axial direction on the basis of the linear gradient distribution in the axial direction.

[0107] Referring to the wave theory, the transfer time Δt of the thermal wave between two points with a known spacing δL can be obtained according to the phase difference of the thermal wave between the two points, and then the transfer speed of the thermal wave can be obtained:

[0108]

[0109] Also knowing the wave speed

[0110]

[0111] According to Equations (30) and (31), the thermal conductivity can be obtained as:

[0112]

[0113] When the temperature of the sample is close to the temperature T a of the gas around it, that is, T≈T a , Equation (28) can be approximated as:

[0114]

[0115] The solution of Equation (33) at this time is:

[0116]

[0117] Equation (34) is in the form of a Fourier series, where the existence of n reflects the temperature gradient in the rod. When n = 0, the gradient disappears and the temperature in the rod tends to be uniform. The solution of Equation (34) is:

[0118]

[0119] The overall temperature of the sample to be measured decays exponentially with time, and further:

[0120]

[0121] ln(T - T a ) has a linear relationship with t. The change of the temperature of the sample during the whole process from the start of periodic heating to the stop of heating is as Figure 4 shown. Considering T in Equation (33)a For the temperature of the gas around the sample, select Figure 4 Fit the data in Region II in

[0122]

[0123] In the periodic cooling section of the steady state stage, select Figure 4 Fit the data in Region I in

[0124]

[0125] According to equations (37) and (38), α / C and β / C can be obtained.

[0126] Return to the heat conduction equation (28) of the sample again, and integrate both sides with respect to space to obtain:

[0127]

[0128] Substitute the boundary conditions:

[0129]

[0130] Obtain:

[0131]

[0132] In the formula and The three terms can be obtained from the experimental data. Combining equations (38) and (39), the specific heat capacity C can be calculated. Then, substituting the specific heat capacity value back into equations (32) and (27), α, β, and κ can be calculated.

[0133] When using Example 2 or 3 to measure the thermophysical parameters, the experimental content and operation steps are as follows:

[0134] Experimental Content 1: Experimental steps for measuring thermophysical parameters at the same heating power by the steady state method:

[0135] 1. Calculate the output voltage of the voltage regulator according to the internal resistance of the heating rod and adjust the voltage regulator.

[0136] 2. The single-chip microcomputer starts the steady state method heating program and outputs a high level.

[0137] 3. Set the data point acquisition interval of the thermometer to 1 second, start the measurement, observe the temperature indication of the thermometer. When the indications of each temperature measurement probe no longer change, wait for about 5 minutes to stop heating, and stop data acquisition when the sample temperature drops to about room temperature.

[0138] 4. Use data processing software such as MATLAB, Origin, and Python to write corresponding data processing programs according to the experimental principle of Example 2, and import the experimental data into the program to obtain the experimental results.

[0139] Experimental content 2: Experimental steps for measuring the thermal physical properties of a copper rod (aluminum rod) under different heating powers by the steady-state method:

[0140] Refer to the operation steps in Experimental content 1. According to the required heating voltages under different powers (10w, 20w, 30w, 40w, 50w), adjust the voltage regulator, and sequentially measure the change of the sample temperature with time under different heating powers. Import the experimental data into the program to obtain the experimental results.

[0141] Experimental content 3: Experimental steps for measuring the thermal physical properties under the same heating power by the dynamic method:

[0142] 1. Calculate the output voltage of the voltage regulator according to the internal resistance of the heating rod and adjust the voltage regulator.

[0143] 2. The single-chip microcomputer starts the dynamic method heating program and outputs periodic high and low levels.

[0144] 3. Set the data point acquisition interval of the thermometer to 1 second, start the measurement, observe the temperature indication of the thermometer. At this time, the temperature of the thermometer should change periodically. Record the peak temperature value. After the peak value is relatively stable, record another 6 - 8 cycles and then stop heating. Wait for the sample to cool down. When the temperature drops to about room temperature, the data acquisition can be stopped.

[0145] 4. Use data processing software such as MATLAB, Origin, and Python to write corresponding data processing programs according to the experimental principle of Example 3, and import the experimental data into the program to obtain the experimental results.

[0146] Experimental content 4: Experimental steps for measuring the thermal physical properties of a copper rod (aluminum rod) under different heating powers:

[0147] Refer to the operation steps in Experimental content 3. According to the required heating voltages under different powers (10w, 20w, 30w, 40w, 50w), adjust the voltage regulator, and sequentially measure the change of the sample temperature with time under different heating powers. Import the experimental data into the program to obtain the experimental results.

[0148] The above embodiments have described the present invention in detail, but the content described is only the preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A measuring device for metal thermal property parameters in an open environment, characterized in that: It includes a heating system and a temperature measurement system; the heating system includes a voltage regulator, a heating rod, a heat insulation board, and a control circuit module. The heating rod is placed in the reserved hole at the bottom end of the sample to be measured. The bottom end of the sample to be measured is placed on the heat insulation board, and its surrounding and top end are exposed to the open space. The voltage regulator, the heating rod, and the control circuit module are electrically connected to heat the sample to be measured; the temperature measurement system includes a single-chip microcomputer, a K-type thermocouple, a temperature conversion chip, and a display screen. By measuring the temperature changes at different positions of the sample, the measurement of thermal conductivity, specific heat capacity, convective heat transfer coefficient, and emissivity is realized.

2. The metal thermal property parameter measurement device in an open environment according to claim 1, wherein: The control circuit module controls the on-off of the voltage regulator. The voltage regulator is electrically connected to the heating rod to heat the sample to be measured by the steady-state method; the voltage regulator and the heating rod are periodically electrically connected to heat the sample to be measured by the dynamic method under different cycle modes.

3. The metal thermal property parameter measurement device in an open environment according to claim 1, characterized in that: The sample to be measured is a slender cylinder.

4. The metal thermal property parameter measuring device in an open environment according to claim 1, wherein: The size of the reserved hole at the bottom end of the sample to be measured is the same as that of the heating rod.

5. The metal thermal property parameter measuring device in an open environment according to claim 1, wherein: The material of the sample to be measured is metal.

6. The metal thermal property parameter measuring device in an open environment according to claim 1, characterized in that: Holes are drilled at different axial positions of the sample to be measured, and the hole depth reaches the center position of the sample to measure the temperature at the center axis position of the sample.

7. The metal thermal property parameter measuring device in an open environment according to claim 1, wherein: The heat insulation board has an opening, and the power cord of the heating rod passes through the heat insulation board and is electrically connected to the voltage regulator and the control circuit module.

8. The metal thermal property parameter measuring device in an open environment according to claim 1, characterized in that: The heat insulation board is made of a high-temperature insulation coefficient aluminum silicate ceramic fiber board.

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