Material emissivity measurement system and material emissivity determination method

Abstract

The present application discloses a material emissivity measurement system and a material emissivity determination method, which relates to the emissivity measurement and radiation temperature measurement technology field, and solves the problem that the material emissivity obtained based on the measured temperature has low accuracy because the temperature of the sample surface will be changed by using a thermocouple to measure the sample temperature. The measurement system includes: a host computer, a temperature control device and a thermometer, the host computer is connected to the temperature control device and the thermometer, the temperature control device is controlled to heat the sample to be tested and the black body furnace to the set temperature, the thermometer is controlled to measure the first temperature, the second temperature, the third temperature and the fourth temperature of the surface of the sample to be tested when the shielding tube reaches different positions, and the host computer determines the target material emissivity of the sample to be tested according to the first temperature, the second temperature, the third temperature and the fourth temperature.

Description

Technical Field

[0001] The present application belongs to the technical field of emissivity measurement and radiation temperature measurement, and more specifically, to a material emissivity measurement system and a material emissivity determination method. Background Art

[0002] In the study of object radiation, emissivity is one of the important physical parameters. Emissivity refers to the ratio of the radiation flux radiated from the surface of an object to the radiation flux radiated by a black body at the same temperature, which represents the radiation capacity of the surface of an object.

[0003] In actual measurement, a thermocouple is mainly used to measure the surface temperature of the sample, and the blackbody radiation energy is calculated based on the surface temperature of the sample, and a radiation thermometer is used to measure the intrinsic radiation energy of the sample surface, and then the emissivity of the sample is calculated based on the intrinsic radiation energy and the blackbody radiation energy. However, the applicant realizes that when using a thermocouple to measure the surface temperature of the sample, the thermocouple needs to be in contact with the sample surface for measurement. Since the sample has a temperature gradient along the thickness direction, that is, the temperature of the sample along the thickness direction is changing, the temperature of the sample surface will change during the contact between the thermocouple and the sample surface. Therefore, there is a deviation between the temperature measured by the thermocouple and the actual surface temperature of the sample, and then there is a deviation between the blackbody radiation energy calculated based on the temperature measured by the thermocouple and the blackbody radiation energy at the actual temperature of the sample. In other words, the calculated blackbody radiation energy has a large error, and then the material emissivity obtained based on the blackbody radiation energy also has a large error, and the accuracy of the material emissivity of the sample obtained by calculation is low. Summary of the invention

[0004] In view of this, the present invention provides a material emissivity measurement system and a material emissivity determination method, the main purpose of which is to solve the current problem that the material emissivity obtained based on the measured temperature has low accuracy because the use of thermocouples to measure the sample temperature will change the temperature distribution on the sample surface.

[0005] According to a first aspect of the present application, there is provided a material emissivity measurement system, comprising: a host computer, a temperature control device and a temperature measuring instrument;

[0006] The host computer is connected to the temperature control device and is used to control the temperature control device to heat the sample to be tested and the black body furnace to a set temperature, wherein the sample to be tested is set at a preset position in the inner cavity of the black body furnace;

[0007] The host computer is connected to the thermometer, and is used to control the thermometer to measure the first temperature of the surface of the sample to be tested when the shielding tube begins to descend, the second temperature of the surface of the sample to be tested when the shielding tube descends to the bottom of the inner cavity of the blackbody furnace and shields the reflected radiation of the blackbody furnace to the sample to be tested, the third temperature of the surface of the sample to be tested when the shielding tube begins to rise, and the fourth temperature of the surface of the sample to be tested when the shielding tube leaves the inner cavity of the blackbody furnace, when it is determined that the temperature control device heats the blackbody furnace and the sample to be tested to the set temperature;

[0008] The host computer is used to determine the target material emissivity of the sample to be tested according to the first temperature, the second temperature, the third temperature and the fourth temperature.

[0009] Optionally, the measurement system further comprises: a sliding guide rail;

[0010] The shielding tube is arranged at a target position on the sliding guide rail, wherein the shielding tube arranged at the target position is outside the black body furnace, and the shielding tube arranged at the target position does not shield the reflected radiation of the black body furnace to the sample to be tested;

[0011] The host computer is connected to the sliding guide rail, and is used to control the sliding guide rail to lower the shielding tube set at the target position to the bottom of the inner cavity of the blackbody furnace when it is determined that the temperature control device heats the blackbody furnace and the sample to be tested to the set temperature, so that the shielding tube can shield the reflected radiation of the blackbody furnace to the sample to be tested, and control the sliding guide rail to raise the shielding tube until the shielding tube reaches the target position.

[0012] Optionally, an argon blowing device is provided in the inner cavity of the black body furnace, and when the sample to be tested needs to be protected against oxidation, argon gas is introduced into the black body furnace.

[0013] Optionally, the blackbody furnace is perpendicular to the ground.

[0014] Optionally, the measurement response speed of the thermometer is less than 50 ms.

[0015] Optionally, the emissivity of the surface of the shielding tube is greater than 0.8.

[0016] According to a second aspect of the present application, a method for determining the emissivity of a material is provided, and a material emissivity measurement system based on any one of the above-mentioned first aspects includes:

[0017] Determine that the sample to be tested and the black body furnace are heated to a set temperature, wherein the sample to be tested is set at a preset position in the inner cavity of the black body furnace;

[0018] Acquire a first temperature of the surface of the sample to be tested when the shielding tube begins to descend, a second temperature of the surface of the sample to be tested when the shielding tube descends to the bottom of the blackbody furnace cavity and shields the reflected radiation of the blackbody furnace to the sample to be tested, a third temperature of the surface of the sample to be tested when the shielding tube begins to rise, and a fourth temperature of the surface of the sample to be tested when the shielding tube leaves the blackbody furnace cavity;

[0019] Determine a first relationship between a first intrinsic radiation energy and a first blackbody radiation energy and an emissivity of a first material, and determine a second relationship between a second intrinsic radiation energy and a second blackbody radiation energy and an emissivity of a second material, wherein the first intrinsic radiation energy is related to the second temperature and a temperature drop, the first blackbody radiation energy is related to the first temperature, the second intrinsic radiation energy is related to the third temperature and a temperature rise, and the second blackbody radiation energy is related to the fourth temperature;

[0020] A target material emissivity is determined based on the first relationship and the second relationship.

[0021] Optionally, the first relationship is:

[0022] L b (T1+ΔT1,λ)=ε1L b (T0, λ),

[0023] Wherein, T0 is the first temperature, T1 is the second temperature, λ is the preset wavelength, ΔT1 is the temperature drop on the surface of the sample to be tested during the descent of the shielding tube, and L b (T0, λ) is the first blackbody radiation energy, L b (T1+ΔT1, λ) is the first intrinsic radiation energy, and ε1 is the emissivity of the first material.

[0024] Optionally, the second relationship is:

[0025] L b (T2-ΔT2,λ)=ε2L b (T3, λ),

[0026] Wherein, T2 is the third temperature, T3 is the fourth temperature, ΔT2 is the temperature rise of the surface of the sample to be tested during the rising process of the shielding tube, and L b (T3, λ) is the second blackbody radiation energy, L b (T2-ΔT2, λ) is the second intrinsic radiation energy, and ε2 is the emissivity of the second material.

[0027] Optionally, determining the target material emissivity based on the first relationship and the second relationship includes:

[0028] Determine ΔT1=ΔT2=ΔT, and determine ε1=ε2=ε,

[0029] Where ΔT is the target temperature change and ε is the target material emissivity;

[0030] Using ΔT and ε to replace ΔT1 and ε1 in the first relationship to obtain a first target relationship;

[0031] Using ΔT and ε to replace ΔT2 and ε2 in the second relationship to obtain a second target relationship;

[0032] The target material emissivity is calculated based on the first target relationship and the second target relationship.

[0033] By means of the above technical scheme, the present application provides a material emissivity measurement system and a material emissivity determination method, the measurement system includes a host computer, a temperature control device and a thermometer, when the host computer controls the temperature control device to heat the blackbody furnace and the sample to be tested to the set temperature, the host computer controls the thermometer to measure the first temperature of the surface of the sample to be tested when the shielding tube begins to descend, the second temperature of the surface of the sample to be tested when the shielding tube descends to the bottom of the blackbody furnace cavity and shields the reflected radiation of the blackbody furnace to the sample to be tested, the third temperature of the surface of the sample to be tested when the shielding tube begins to rise, and the fourth temperature of the surface of the sample to be tested when the shielding tube leaves the blackbody furnace cavity, the host computer determines the material emissivity of the sample to be tested based on the four measured temperatures; the temperature measurement can be automatically performed through the material emissivity measurement system, at the same time, the temperature drop and temperature rise of the shielding tube descending and rising process are included in the emissivity solution process of the above-mentioned first relationship and second relationship, and the obtained emissivity has a higher accuracy.

[0034] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0036] Figure 1A A schematic diagram of the structure of a material emissivity measurement system provided in an embodiment of the present application is shown;

[0037] Figure 1B A schematic diagram showing the positional relationship between a black body furnace and a sample to be tested in another material emissivity measurement system provided in an embodiment of the present application when the sample to be tested is not shielded;

[0038] Figure 1C A schematic diagram showing the positional relationship between a black body furnace and a sample to be tested in another material emissivity measurement system provided in an embodiment of the present application when the sample to be tested is shielded;

[0039] Figure 2 A flow chart of a method for determining the emissivity of a material provided in an embodiment of the present application is shown;

[0040] Figure 3 A flow chart of another method for determining the emissivity of a material provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0041] Various aspects and features of the present application are described herein with reference to the accompanying drawings.

[0042] It should be understood that various modifications may be made to the embodiments of the present application. Therefore, the above description should not be considered as limiting, but only as an example of an embodiment. Other modifications within the scope and spirit of the present application will occur to those skilled in the art.

[0043] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0044] These and other characteristics of the present application will become apparent from the following description of a preferred form of embodiment given as a non-limiting example with reference to the accompanying drawings.

[0045] It should also be understood that although the present application has been described with reference to some specific examples, those skilled in the art will be able to readily implement many other equivalent forms of the present application.

[0046] The above and other aspects, features and advantages of the present application will become more apparent in view of the following detailed description when taken in conjunction with the accompanying drawings.

[0047] Specific embodiments of the present application are described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments applied for are merely examples of the present application, which may be implemented in a variety of ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that obscure the present application. Therefore, the specific structural and functional details applied for herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present application in a variety of ways with substantially any suitable detailed structure.

[0048] This specification may use the phrases "in one embodiment," "in another embodiment," "in yet another embodiment," or "in other embodiments," all of which may refer to one or more of the same or different embodiments according to the present application.

[0049] The present application embodiment provides a material emissivity measurement system, such as Figure 1A As shown, it includes: a host computer (not shown), a temperature control device 2 and a temperature measuring instrument 6.

[0050] Specifically, the host computer is connected to the temperature control device 2, and is used to control the temperature control device 2 to heat the sample to be tested 1 and the blackbody furnace 3 to a set temperature, wherein the sample to be tested 1 is arranged at a preset position in the inner cavity of the blackbody furnace 3; the host computer is connected to the thermometer 6, and is used to control the thermometer 6 to measure the first temperature of the surface of the sample to be tested 1 when the shielding tube 4 starts to descend, the second temperature of the surface of the sample to be tested 1 when the shielding tube 4 descends to the bottom of the inner cavity of the blackbody furnace 3 and shields the reflected radiation of the blackbody furnace 3 to the sample to be tested 1, the third temperature of the surface of the sample to be tested 1 when the shielding tube 4 starts to rise, and the fourth temperature of the surface of the sample to be tested 1 when the shielding tube 4 leaves the inner cavity of the blackbody furnace 3 when it is determined that the temperature control device 2 heats the blackbody furnace 3 and the sample to be tested 1 to the set temperature; the host computer is used to execute the method for determining the emissivity of the material.

[0051] It should be noted that the state of the shielding tube 4 outside the black body furnace 3 can be understood as a non-shielding state, which can be understood as an ideal state. The specific position relationship between the sample 1 to be tested and the black body furnace 3 is as follows: Figure 1B As shown, the radiation energy emitted by the sample 1 to be tested measured by the thermometer 6 includes two parts: one is the reflected radiation energy 9 given to the surface of the sample 1 to be tested by the black body furnace 3, and the other is the inherent radiation energy 10 emitted by the surface of the sample 1 to be tested itself;

[0052] The case where the shielding tube 4 reaches the bottom of the black body furnace 3 is a shielding case. The shielding case can be understood as the reflected radiation energy 9 given to the sample 1 by the black body furnace 3 is blocked by the shielding tube 4. At this time, the specific position relationship between the sample 1 to be tested and the black body furnace 3 is as follows: Figure 1CAs shown, the radiation energy emitted by the sample 1 to be tested measured by the thermometer 6 is only the inherent radiation energy 10 emitted by the surface of the sample 1 to be tested. It should be further explained that the first, second, third and fourth of the first temperature, second temperature, third temperature and fourth temperature have no meaning and are only used for distinction.

[0053] Furthermore, the blackbody furnace 3 is provided with an argon blowing device (not shown). When the sample to be tested needs to be protected against oxidation, argon is introduced into the blackbody furnace. Argon is introduced in large quantities during the heating stage to fill the vertical blackbody furnace with argon. After the temperature stabilizes, argon is slowly introduced in small quantities (for example, 30 mL / min) to maintain the non-oxidizing environment in the blackbody furnace. The introduction of argon does not significantly affect the isothermality of the blackbody furnace cavity, that is, the effective emissivity caused by argon blowing after the blackbody furnace is kept at a constant temperature is greater than or equal to 0.99. At the same time, the measurement response speed of the thermometer 6 is less than 50 ms, and the emissivity of the surface of the shielding tube 4 is greater than 0.8. At the same time, the shielding tube 4 is made of a high-emissivity material tube such as an aluminum or aluminum alloy tube with anodized surface, or a graphite tube, or a carbon fiber tube.

[0054] It should be noted that the host computer can be understood as a computer or device specifically used to control an industrial automation system, which has processing and control functions, and performs real-time monitoring, regulation and command of industrial production processes. In this application, it can be connected to the temperature control device 2 and the thermometer 6 to control the temperature control device 2 and the thermometer 6, and to obtain data generated or obtained by the temperature control device 2 and the thermometer 6, and to process and analyze the data.

[0055] It should be noted that the temperature control device 2 can be understood as a device for controlling the temperature during the heating process of an object. The temperature rise of the heated material mainly depends on the power of the radiator and the type of the heated material. In addition, different materials require different heating temperatures, and voltage fluctuations also affect the heating temperature. For example, devices such as thermostats and intelligent temperature controllers that achieve temperature control. The temperature control device 2 is a prior art and will not be described in detail here.

[0056] Furthermore, if Figure 1AAs shown, the material emissivity measurement system also includes a sliding guide rail 5 and a thermocouple (not shown). The measurement system is fixed by a bracket 8, the thermometer 6 is fixed at a first preset position on the bracket 8, the sliding guide rail 5 is fixed at a second preset position on the bracket 8, the bracket 8 is preferably an aluminum bracket, and the shielding tube 4 is set at a target position on the sliding guide rail 5, wherein the shielding tube 4 set at the target position is outside the black body furnace 3, and the shielding tube 4 set at the target position does not shield the reflected radiation of the black body furnace 3 to the sample 1 to be tested. The blackbody furnace 3 is placed vertically on the ground, that is, the blackbody furnace 3 is placed vertically so that its light hole faces directly upwards, the sample 1 to be tested is made into a cylindrical shape with a specific thickness and placed in the center of the cavity of the blackbody furnace 3, and the sliding guide rail 4 is connected to the host computer. When the host computer determines that the temperature control device 2 heats the blackbody furnace 3 and the sample 1 to be tested to the set temperature, the sliding guide rail 5 is controlled to lower the shielding tube 4 set at the target position to the bottom of the inner cavity of the blackbody furnace 3, so that the shielding tube 4 blocks the reflected radiation of the blackbody furnace 3 to the sample 1 to be tested, and the sliding guide rail 5 is controlled to raise the shielding tube 4 until the shielding tube 4 reaches the target position.

[0057] Furthermore, if Figure 1A As shown, the measurement system further includes a temperature processing and display module 7 , which can be connected to the thermometer 6 for processing and displaying the temperature measured by the thermometer 6 .

[0058] It should be noted that the temperature measuring area of ​​the above-mentioned thermometer 6 is located on the surface of the sample to be tested, the size of the temperature measuring area is less than 0.8 times the size of the sample, and when the sample to be tested is placed in the blackbody furnace, it has little effect on the effective emissivity of the blackbody furnace, that is, the effective emissivity of the blackbody furnace after placing the sample to be tested must be greater than or equal to 0.99.

[0059] The measurement system provided in the embodiment of the present application includes a host computer, a temperature control device and a thermometer. The host computer of the measurement system controls the temperature control device to raise the temperature of the black body furnace to the set temperature, and then controls the thermometer to measure the first temperature of the sample to be tested when the shielding tube begins to descend, and then controls the sliding guide rail to place the shielding tube at the bottom of the black body furnace to shield the sample to be tested, and then continues to control the thermometer to measure the second temperature of the sample to be tested when the shielding tube descends to the bottom of the black body furnace cavity and shields the reflected radiation of the black body furnace to the sample to be tested, and then controls the sliding guide rail to make the shielding tube rise, and controls the thermometer to measure the third temperature of the sample to be tested when the shielding tube begins to rise, and continues to let the shielding tube rise. The tube rises until it leaves the blackbody furnace, and the temperature measuring instrument is controlled to measure the fourth temperature of the sample to be tested when the shielding tube leaves the inner cavity of the blackbody furnace. The upper computer can obtain the first relationship and the second relationship based on the first temperature, the second temperature, the third temperature and the fourth temperature obtained in combination with the Planck formula of thermal radiation, and then obtain the material emissivity of the sample to be tested by calculation according to the first relationship and the second relationship. The measurement system of the material emissivity can automatically perform the measurement of relevant parameters. The emissivity solution process of the above-mentioned first relationship and the second relationship includes the temperature drop and temperature rise of the shielding tube in the process of descending and rising, and the obtained emissivity has a higher accuracy.

[0060] Furthermore, the present application embodiment provides a method for determining the emissivity of a material, based on the material emissivity measurement system, such as Figure 2 As shown, including:

[0061] 101. Ensure that the sample to be tested and the black body furnace are heated to the set temperature.

[0062] In the embodiment of the present application, the execution subject is a host computer, which includes a controller and a processor. The controller has a control function, and the processor has a processing function. The sample to be tested needs to be set in advance at a preset position in the inner cavity of the blackbody furnace. This preset position can be the center position of the bottom of the blackbody furnace cavity. After that, the temperature control device heats the sample to be tested and the blackbody furnace to the set temperature. When the host computer determines that the sample to be tested and the blackbody furnace have reached the set temperature, it executes subsequent steps. There are two cases here. One is that when it is determined that the sample to be tested and the blackbody furnace have been heated to the set temperature, the shielding tube is immediately lowered to the bottom of the blackbody furnace. The other case is that after the sample to be tested and the blackbody furnace reach the set temperature, the set temperature is stabilized, and the shielding tube can be started to be lowered to the bottom of the blackbody furnace at any time. It should be further explained that the sample to be tested is prepared in advance, that is, the sample to be tested is made into a preset thickness and cylindrical shape in advance.

[0063] 102. Obtain a first temperature of the surface of the sample to be tested when the shielding tube begins to descend, a second temperature of the surface of the sample to be tested when the shielding tube descends to the bottom of the blackbody furnace cavity and shields the reflected radiation of the blackbody furnace to the sample to be tested, a third temperature of the surface of the sample to be tested when the shielding tube begins to rise, and a fourth temperature of the surface of the sample to be tested when the shielding tube leaves the blackbody furnace cavity.

[0064] In an embodiment of the present application, when determining that the sample to be tested and the blackbody furnace are heated to the set temperature, the host computer needs to obtain through a thermometer a first temperature of the surface of the sample to be tested when the shielding tube begins to descend, a second temperature of the surface of the sample to be tested when the shielding tube descends to the bottom of the blackbody furnace cavity and shields the reflected radiation of the blackbody furnace to the sample to be tested, a third temperature of the surface of the sample to be tested when the shielding tube begins to rise, and a fourth temperature of the surface of the sample to be tested when the shielding tube leaves the blackbody furnace cavity.

[0065] 103. Determine a first relationship between the first intrinsic radiation energy and the first blackbody radiation energy and the emissivity of the first material, and determine a second relationship between the second intrinsic radiation energy and the second blackbody radiation energy and the emissivity of the second material.

[0066] In the embodiment of the present application, since there is a corresponding relationship between temperature and radiation energy, after determining the first temperature, the second temperature, the third temperature and the fourth temperature, the first blackbody radiation energy related to the first temperature, the first intrinsic radiation energy related to the second temperature and the temperature drop, the second intrinsic radiation energy related to the third temperature and the temperature drop, and the second blackbody radiation energy related to the fourth temperature can also be determined. Then, combined with the Planck formula for thermal radiation, the first relationship between the first intrinsic radiation energy and the first blackbody radiation energy and the emissivity of the first material, as well as the second relationship between the second intrinsic radiation energy and the second blackbody radiation energy and the emissivity of the second material are constructed.

[0067] 104. Determine the emissivity of the target material based on the first relationship and the second relationship.

[0068] In the embodiment of the present application, the first relationship and the second relationship are jointly solved, that is, a two-variable quadratic equation is solved, and the emissivity of the target material can be obtained by calculation.

[0069] The method provided in the embodiment of the present application first determines that the sample to be tested and the blackbody furnace are heated to a set temperature, and then obtains through a thermometer a first temperature of the surface of the sample to be tested when the shielding tube begins to descend, a second temperature of the surface of the sample to be tested when the shielding tube descends to the bottom of the blackbody furnace cavity and shields the reflected radiation of the blackbody furnace to the sample to be tested, a third temperature of the surface of the sample to be tested when the shielding tube begins to rise, and a fourth temperature of the surface of the sample to be tested when the shielding tube leaves the blackbody furnace cavity, and then determines a first relationship between the first inherent radiation energy and the first blackbody radiation energy and the emissivity of the first material, and determines a second relationship between the second inherent radiation energy and the second blackbody radiation energy and the emissivity of the second material, and finally determines the emissivity of the target material based on the first relationship and the second relationship; two equations are established through the first temperature, the second temperature, the third temperature and the fourth temperature, the first relationship and the second relationship, and the two equations are quadratic equations of two variables, and the emissivity of the target material can be obtained by solving them. The above-mentioned solution process includes two temperature changes, the temperature drop during the descent of the shielding tube and the temperature rise during the rise of the shielding tube, and the obtained emissivity of the target material has high accuracy.

[0070] Further, as a refinement and extension of the specific implementation of the above embodiment, in order to fully illustrate the specific implementation process of this embodiment, the embodiment of the present application provides another method for determining the emissivity of a material, such as Figure 3 As shown, including:

[0071] 201. Ensure that the sample to be tested and the black body furnace are heated to the set temperature.

[0072] 202. Obtain a first temperature of the surface of the sample to be tested when the shielding tube begins to descend, a second temperature of the surface of the sample to be tested when the shielding tube descends to the bottom of the blackbody furnace cavity and shields the reflected radiation of the blackbody furnace to the sample to be tested, a third temperature of the surface of the sample to be tested when the shielding tube begins to rise, and a fourth temperature of the surface of the sample to be tested when the shielding tube leaves the blackbody furnace cavity.

[0073] In an embodiment of the present application, the temperature is measured by a thermometer. When the shielding tube begins to descend, it is outside the inner cavity of the blackbody furnace and has no shielding effect on the sample, that is, the blackbody furnace has reflected radiation to the sample to be tested. When the shielding tube begins to descend, the host computer measures the first temperature of the sample to be tested through the thermometer. When the shielding tube descends to the bottom of the inner cavity of the blackbody furnace and shields the reflected radiation of the blackbody furnace to the sample to be tested, the thermometer measures the second temperature of the surface of the sample to be tested. When the shielding tube begins to rise, the thermometer measures the third temperature of the surface of the sample to be tested. At this time, the shielding tube still completely shields the sample to be tested. When the shielding tube leaves the inner cavity of the blackbody furnace, the thermometer measures the third temperature of the surface of the sample to be tested. At this time, the shielding tube does not shield the sample, that is, it does not shield the reflected radiation of the blackbody furnace to the sample to be tested.

[0074] Furthermore, in the embodiment of the present application, the thermometer is preferably a radiation thermometer. The principle of the radiation thermometer is based on the relationship between the radiation energy of an object and its temperature, that is, Planck's formula. The temperature of the object is calculated by measuring the energy radiated by the object. The thermometer is pre-set directly above the blackbody furnace, and the measurement area of ​​the thermometer is located on the surface of the sample to be measured. Since the radiation thermometer is a prior art, no further explanation is given.

[0075] 203. Determine a first relationship between the first intrinsic radiation energy and the first blackbody radiation energy and the emissivity of the first material, and determine a second relationship between the second intrinsic radiation energy and the second blackbody radiation energy and the emissivity of the second material.

[0076] In the embodiment of the present application, the first relationship is:

[0077] L b (T1+ΔT1,λ)=ε1L b (T0, λ),

[0078] Wherein, T0 is the first temperature, T1 is the second temperature, λ is the preset wavelength, ΔT1 is the temperature drop on the surface of the sample to be tested during the descent of the shielding tube, and L b (T0, λ) is the first blackbody radiation energy, L b (T1+ΔT1, λ) is the first intrinsic radiation energy, and ε1 is the first material emissivity.

[0079] The specific formulas for the first intrinsic radiation energy and the first blackbody radiation energy are as follows:

[0080]

[0081]

[0082] Wherein, c1 and c2 are the first radiation constant and the second radiation constant, which are 3.7419*10-16W·m2 and 1.4388*10-2m·K respectively.

[0083] Furthermore, the second relationship is:

[0084] L b (T2-ΔT2,λ)=ε2L b (T3, λ),

[0085] Wherein, T2 is the third temperature, T3 is the fourth temperature, ΔT2 is the temperature rise of the surface of the sample to be tested during the rising process of the shielding tube, and L b (T3, λ) is the second blackbody radiation energy, L b (T2-ΔT2, λ) is the second intrinsic radiation energy, and ε2 is the emissivity of the second material.

[0086] The specific formulas for the first intrinsic radiation energy and the first blackbody radiation energy are as follows:

[0087]

[0088]

[0089] 204. Determine the emissivity of the target material based on the first relationship and the second relationship.

[0090] In the embodiment of the present application, since the temperature changes during the shading tube descending process and the shading tube rising process are symmetrical, the temperature drop on the surface of the sample to be tested during the shading tube descending process is approximately equal to the temperature rise on the surface of the sample to be tested during the shading tube rising process. At the same time, since the difference between the first temperature and the fourth temperature is small, and the emissivity of the first material and the emissivity of the second material are both related to the preset wavelength and temperature, the preset wavelength remains unchanged, and the difference between the first temperature and the fourth temperature is small, the emissivity of the first material and the emissivity of the second material are also approximately equal. It can be determined that ΔT1=ΔT2=ΔT, and ε1=ε2=ε, wherein ΔT is the target temperature change, and ε is the target material emissivity; ΔT and ε are used to replace ΔT1 and ε1 in the first relationship to obtain the first target relationship, and ΔT2 and ε2 in the second relationship are used to replace ΔT and ε to obtain the second target relationship. The emissivity of the target material can be calculated based on the first target relationship and the second target relationship.

[0091] 205. Compare the target material emissivity of the sample to be tested with the emissivity threshold to obtain a comparison result.

[0092] In the embodiment of the present application, the material emissivity obtained in the above 204 can be further verified. Because measurement errors may occur in the actual measurement process, in order to avoid the adverse effects of this situation on the results, an emissivity threshold can be obtained. When it is detected that the emissivity of the target material exceeds the emissivity threshold, the first updated temperature of the surface of the sample to be tested when the shielding tube starts to descend again, the second updated temperature of the surface of the sample to be tested when the shielding tube descends to the bottom of the blackbody furnace cavity again and shields the reflected radiation of the blackbody furnace to the sample to be tested, the third updated temperature of the surface of the sample to be tested when the shielding tube starts to rise again, and the fourth updated temperature of the surface of the sample to be tested when the shielding tube leaves the blackbody furnace cavity again are obtained to determine the first updated temperature. The first updated relationship between the intrinsic radiation energy and the first updated blackbody radiation energy and the first updated material emissivity is determined, and the second updated relationship between the second updated intrinsic radiation energy and the second updated blackbody radiation energy and the second updated material emissivity is determined. The updated target material emissivity is determined based on the first updated relationship and the second updated relationship. Repeat the above steps until the updated target material emissivity does not exceed the emissivity threshold, where the first updated intrinsic radiation energy is the energy related to the second updated temperature and the updated temperature drop, the first updated blackbody radiation energy is the energy related to the first updated temperature, the second updated intrinsic radiation energy is the energy related to the third updated temperature and the updated temperature rise, and the second updated blackbody radiation energy is the energy related to the fourth updated temperature. At the same time, there is another situation that the emissivity of the target material of the sample to be tested does not exceed the emissivity threshold, which means that the calculated material emissivity of the sample to be tested is reliable. If the measurement is repeated many times, that is, the number of repeated measurements exceeds the number threshold, it means that the first temperature, the second temperature, the third temperature and the fourth temperature obtained by measurement are inaccurate, indicating that there is a problem in the measurement process, which may be a failure of the measurement equipment or a problem with the relevant test parameters in the measurement process, and a fault or problem troubleshooting is required.

[0093] Furthermore, in order to further improve the accuracy of the calculated material emissivity, in the actual measurement process, the thermometer can be used for measurement multiple times. For example, 10 measurements are taken. The calculation process after each measurement is as shown above, and 10 reflectivities are finally obtained. The average value of these 10 reflectivities can be used as the reflectivity of the final material of the sample to be tested. The above method can improve the accuracy of the calculated material reflectivity and reduce errors.

[0094] A specific measurement step can be summarized as:

[0095] 301. The blackbody furnace is placed vertically so that the light hole faces upward. The sample to be tested is made into a cylindrical shape with a specific thickness and placed in the center of the blackbody furnace cavity. The sliding guide rail is fixed vertically on the aluminum frame and the shielding tube is fixed on the slider of the sliding guide rail. At the same time, an infrared thermometer is placed on the aluminum frame.

[0096] 302. Raise the temperature of the black body furnace and the sample to be tested to the set temperature.

[0097] 303. Control the slider of the sliding guide rail to let the shielding tube descend into the black body furnace cavity. The temperature measuring instrument measures the reflected radiation given to the surface of the sample to be tested by the shielding tube from the beginning of shielding to the complete shielding of the black body furnace cavity, and obtains the surface temperatures T0 and T1 of the sample to be tested before and after shielding.

[0098] 304. Control the slider of the sliding guide rail to make the shielding tube rise. The temperature measuring instrument measures the reflected radiation given to the surface of the sample to be tested by the shielding tube from the beginning of rising to the time when the shielding tube completely does not shield the inner cavity of the black body furnace, and obtains the surface temperatures T2 and T3 of the sample to be tested when the reflected radiation is completely shielded and completely not shielded.

[0099] 305. The host computer constructs two equations based on the obtained four temperatures T0, T1, T2, and T3 and combines Planck's formula to calculate, thereby obtaining the material emissivity of the sample 1 to be tested.

[0100] The method provided in the embodiment of the present application can obtain the emissivity of the target material by solving the problem. The solution process includes two temperature changes: the temperature drop during the descent process of the shielding tube and the temperature rise during the ascending process of the shielding tube. The obtained emissivity of the target material has a high accuracy.

[0101] Those skilled in the art will appreciate that the accompanying drawings are merely schematic diagrams of a preferred implementation scenario, and the modules or processes in the accompanying drawings are not necessarily required for implementing the present application.

[0102] The above embodiments are only exemplary embodiments of the present application and are not intended to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and protection scope of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present application.

Claims

1. A material emissivity measurement system, characterized in that: include: Host computer, temperature control device and temperature measuring instrument; It also includes: a shielding tube and a sliding guide rail; the shielding tube is arranged at a target position on the sliding guide rail, wherein the shielding tube arranged at the target position is outside the black body furnace, and the shielding tube arranged at the target position does not shield the reflected radiation of the black body furnace to the sample to be tested; The host computer is connected to the temperature control device and is used to control the temperature control device to heat the sample to be tested and the black body furnace to a set temperature, wherein the sample to be tested is set at a preset position in the inner cavity of the black body furnace; The host computer is connected to the thermometer and the sliding guide rail. When it is determined that the temperature control device heats the black body furnace and the sample to be tested to the set temperature, the host computer is used to control the sliding guide rail to lower the shielding tube set at the target position to the bottom of the black body furnace cavity so that the shielding tube shields the reflected radiation of the black body furnace to the sample to be tested, and control the thermometer to measure the first temperature of the surface of the sample to be tested when the shielding tube starts to descend, and the second temperature of the surface of the sample to be tested when the shielding tube descends to the bottom of the black body furnace cavity and shields the reflected radiation of the black body furnace to the sample to be tested; the host computer is also used to control the sliding guide rail to raise the shielding tube from the bottom of the black body furnace cavity until the shielding tube reaches the target position, and control the thermometer to measure the third temperature of the surface of the sample to be tested when the shielding tube starts to rise, and the fourth temperature of the surface of the sample to be tested when the shielding tube leaves the black body furnace cavity; The host computer is used to determine the target material emissivity of the sample to be tested according to the first temperature, the second temperature, the third temperature and the fourth temperature; Wherein, determining the target material emissivity of the sample to be tested according to the first temperature, the second temperature, the third temperature and the fourth temperature includes: determining a first relationship between the first intrinsic radiation energy and the first blackbody radiation energy and the first material emissivity, and determining a second relationship between the second intrinsic radiation energy and the second blackbody radiation energy and the second material emissivity; determining ΔT1=ΔT2=ΔT, and determining ε1=ε2=ε, ΔT1 is the temperature drop on the surface of the sample to be tested during the descent of the shielding tube, ΔT2 is the temperature rise on the surface of the sample to be tested during the ascent of the shielding tube, ΔT is the target temperature change, ε1 is the first material emissivity, ε2 is the second material emissivity, ε is the target material emissivity, and substituting the target temperature change and the target material emissivity into the first relationship and the second relationship respectively; determining the target material emissivity based on the first relationship and the second relationship; the first intrinsic radiation energy is related to the second temperature and the temperature drop, the first blackbody radiation energy is related to the first temperature, the second intrinsic radiation energy is related to the third temperature and the temperature rise, and the second blackbody radiation energy is related to the fourth temperature; The first relationship is: L b (T1+ΔT1,λ)=ε1L b (T0,λ), Wherein, T0 is the first temperature, T1 is the second temperature, λ is the preset wavelength, L b (T0, λ) is the first blackbody radiation energy, L b (T1+ΔT1, λ) is the first intrinsic radiation energy; The second relationship is: L b (T2-ΔT2,λ)=ε2L b (T3,λ), Wherein, T2 is the third temperature, T3 is the fourth temperature, L b (T3, λ) is the second blackbody radiation energy, L b (T2-ΔT2, λ) is the second inherent radiation energy.

2. The material emissivity measurement system according to claim 1, characterized in that: An argon blowing device is provided in the inner cavity of the black body furnace. When the sample to be tested needs to be protected against oxidation, argon gas is introduced into the black body furnace.

3. The material emissivity measurement system according to claim 1, characterized in that: The black body furnace is vertical to the ground.

4. The material emissivity measurement system according to claim 1, characterized in that: The measurement response speed of the temperature measuring instrument is less than 50ms.

5. The material emissivity measurement system according to claim 1, characterized in that: The emissivity of the surface of the shielding tube is greater than 0.

8.

6. A method for determining material emissivity, based on the material emissivity measurement system according to any one of claims 1 to 5, characterized in that: include: Determine that the sample to be tested and the black body furnace are heated to a set temperature, wherein the sample to be tested is set at a preset position in the inner cavity of the black body furnace; Acquire a first temperature of the surface of the sample to be tested when the shielding tube begins to descend, a second temperature of the surface of the sample to be tested when the shielding tube descends to the bottom of the blackbody furnace cavity and shields the reflected radiation of the blackbody furnace to the sample to be tested, a third temperature of the surface of the sample to be tested when the shielding tube begins to rise, and a fourth temperature of the surface of the sample to be tested when the shielding tube leaves the blackbody furnace cavity; Determine a first relationship between a first intrinsic radiation energy and a first blackbody radiation energy and an emissivity of a first material, and determine a second relationship between a second intrinsic radiation energy and a second blackbody radiation energy and an emissivity of a second material, wherein the first intrinsic radiation energy is related to the second temperature and a temperature drop, the first blackbody radiation energy is related to the first temperature, the second intrinsic radiation energy is related to the third temperature and a temperature rise, and the second blackbody radiation energy is related to the fourth temperature; Determine ΔT1=ΔT2=ΔT, and determine ε1=ε2=ε, ΔT1 is the temperature drop on the surface of the sample to be tested when the shielding tube is descending, ΔT2 is the temperature rise on the surface of the sample to be tested when the shielding tube is ascending, ΔT is the target temperature change, ε1 is the emissivity of the first material, ε2 is the emissivity of the second material, and ε is the emissivity of the target material, substitute the target temperature change and the emissivity of the target material into the first relationship and the second relationship respectively, and determine the emissivity of the target material based on the first relationship and the second relationship; The first relationship is: L b (T1+ΔT1,λ)=ε1L b (T0,λ), Wherein, T0 is the first temperature, T1 is the second temperature, λ is the preset wavelength, L b (T0, λ) is the first blackbody radiation energy, L b (T1+ΔT1, λ) is the first intrinsic radiation energy; The second relationship is: L b (T2-ΔT2,λ)=ε2L b (T3,λ), Wherein, T2 is the third temperature, T3 is the fourth temperature, L b (T3, λ) is the second blackbody radiation energy, L b (T2-ΔT2, λ) is the second inherent radiation energy.

7. The method for determining the material emissivity according to claim 6, characterized in that: Determining ΔT1=ΔT2=ΔT, and determining ε1=ε2=ε, substituting the target temperature change and the target material emissivity into the first relationship and the second relationship, respectively, and determining the target material emissivity based on the first relationship and the second relationship, including: Determine ΔT1=ΔT2=ΔT, and determine ε1=ε2=ε, Using ΔT and ε to replace ΔT1 and ε1 in the first relationship to obtain a first target relationship; Using ΔT and ε to replace ΔT2 and ε2 in the second relationship to obtain a second target relationship; The target material emissivity is calculated based on the first target relationship and the second target relationship.

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