Multi-spectral temperature measurement reflected light characterization calibration device and method based on heat flow sensor in transient radiation heating environment

Abstract

The invention provides a multispectral temperature measurement reflected light characterization calibration device and method based on a heat flow sensor in a transient radiation heating environment. The device comprises a water cooling radiator, a multispectral temperature measurement instrument, a heater, the heat flow sensor and a supporting device. And establishing a spectral radiance matrix database of heater reflected light interference based on the heat flux sensor as an index. In the testing process, according to the space heat flow value tested by the heat flow sensor, the reflected light interference of the heater can be obtained in real time through the database, the reflected light interference of the heater can be removed in real time in the algorithm by combining the spectral emissivity model of the material, and therefore the real temperature of the surface of the thermal structure can be obtained. According to the invention, the problem of interference of reflected light of the heater on characterization and real-time correction in a transient radiation heating environment is solved, and the temperature measurement precision is improved.

Description

Technical Field

[0001] The present invention belongs to the field of radiation heat test temperature measurement, and in particular relates to a multi-spectral temperature measurement reflected light characterization calibration device and method based on a heat flux sensor in a transient radiation heating environment. Background Art

[0002] Radiation heat test technology is a ground simulation test technology developed to solve the thermal barrier problem that occurs after the aircraft crosses the speed of sound, in order to study the bearing capacity and thermal characteristics of the aircraft under the action of force and thermal environment. Usually, heating elements such as quartz lamps and graphite are used to heat the test piece by high-temperature radiation. Among them, the temperature parameter is the thermal environment parameter based on the radiation heat test. Temperature testing mainly uses two technologies: contact and non-contact. Contact temperature measurement mainly uses thermocouple sensors, which have the characteristics of low cost and high temperature measurement accuracy, but the long-term use temperature is below 1600℃ (type B thermocouple); tungsten-rhenium thermocouples have a high melting point (above 3000℃) and a large thermoelectric potential, but they are very easy to oxidize quickly at above 500℃, resulting in temperature measurement failure. In addition, contact temperature measurement pastes sensors such as thermocouples on the surface of the structure, which will change the thermal field distribution of the structure. In comparison, non-contact temperature measurement does not require contact with the object being measured, but instead solves the temperature of the target being measured based on the law of thermal radiation, thus not destroying the thermal field distribution of the structure. It has the advantages of a wide temperature measurement range and fast response time, and plays a vital role in radiation heating tests.

[0003] Non-contact temperature measurement is mainly based on radiation temperature measurement, which can be divided into single spectrum temperature measurement, colorimetric temperature measurement and multi-spectrum temperature measurement. In the radiation heating environment, the radiation measurement signal brightness I of the radiation thermometer includes: the spontaneous radiation brightness I of the target object received by the radiation thermometer ε , the radiation brightness reflected by the target object I ρ (mainly due to the interference of reflected light from the high temperature heater), namely:

[0004] I=I ε +I ρ =εI b +ρI e (1)

[0005] Among them, I b is the spontaneous radiation brightness of the target object, I e is the heater radiation interference, ε is the spectral emissivity of the target object, ρ is the reflectivity of the target object. According to Kirchhoff's law, for a non-transmissive object, the sum of its emissivity and reflectivity is 1, then: ρ = 1-ε.

[0006] From the above formula, it can be seen that the main factors affecting the accuracy of radiation temperature measurement are the emissivity of the measured target and the interference of the reflected light from the heater. In particular, the influence of the reflected light interference from the heater causes the energy received by the radiation thermometer to be higher than the energy radiated by the specimen itself. Strong radiation reflection in a high-temperature radiation environment seriously affects the accuracy of radiation temperature measurement based on the Planck thermal radiation principle.

[0007] The multi-spectral radiation temperature measurement method measures the radiation brightness under multiple spectra, combines a specific spectral emissivity function, constructs a multi-wavelength radiation measurement equation, and realizes temperature measurement. The multi-spectral temperature measurement method is suitable for measurements with unknown target emissivity. At present, multi-spectral temperature measurement technology mainly focuses on how to solve the problem of matching the emissivity model with the spectral emissivity of the object being measured, while how to remove the radiation background interference is rarely reported in public literature. The existing method can only characterize the heater reflected light interference under thermal stability, and cannot characterize and perform real-time feedback calibration in a transient environment. There is no mature solution for real-time correction of heater reflected light interference in radiation thermal tests reported at home and abroad.

[0008] To solve the technical problem that the reflected light interference of multi-spectral temperature measurement in transient radiation heating environment cannot be characterized and calibrated, the problems of existing methods are mainly manifested in the following points:

[0009] 1) The existing method characterizes the reflected light interference of the heater in the following steps: manually apply a voltage to both ends of the heater, and after the heat stabilizes, record the radiation spectrum value of the heater at this time (i.e., reflected light interference). Change the applied voltage value and repeat this process, and use the steady-state radiation spectrum values ​​under different voltages to characterize the reflected light interference of the heater. Because the measured data is limited, the data under the steady-state environment is applied to the transient heating environment, which cannot accurately characterize the reflected light interference of the heater under the rapidly changing transient heating environment, causing large errors in the subsequent temperature measurement results. Therefore, the existing method is only suitable for the characterization of the reflected light interference of the heater under the thermally stable state, and is not suitable for the transient heating environment.

[0010] 2) The specific steps of the existing method for correcting and calibrating reflected light are: applying the same voltage at both ends of the heater, and after the heat stabilizes, manually removing the above-obtained heater radiation spectrum value from the total radiation spectrum, thereby eliminating the influence of the heater reflected light interference. The existing method is limited to manually removing the influence of reflected light in a steady-state environment, and cannot be used for automatic real-time correction and calibration in a transient heating environment. Summary of the invention

[0011] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a multi-spectral temperature measurement reflected light characterization and calibration device and method based on a heat flux sensor in a transient radiation heating environment, forming a heat flux q-spectral radiation brightness I matrix calibration database, thereby realizing the characterization and calibration of reflected light interference in the radiation heating environment, and further through a multi-spectral temperature measurement algorithm, the temperature measurement accuracy can be improved.

[0012] This embodiment provides a multi-spectral temperature measurement and calibration device for characterizing heater reflected light interference in a radiation heating environment. The device includes: a water-cooled radiator, a multi-spectral temperature meter, a heater, a heat flux sensor and a supporting device.

[0013] The water-cooled radiator is used to test and analyze the spectral characteristics of the heater's radiation brightness. It consists of a standard reflector, a bottom water-cooling tooling, a side water-cooling tooling and a heat conducting sheet.

[0014] The multi-spectral thermometer is used to obtain the spectral radiation brightness of the heater.

[0015] The heater consists of a reflective plate and a heating element.

[0016] The heat flow sensor is installed on the reflector to test the spatial heat flow of the heater. To prevent high temperature damage during the thermal test, the heat flow sensor is usually designed as a water-cooled structure.

[0017] The supporting device is a flat plate, which maintains the same radiation environment as the formal test. The water-cooled radiator is embedded in the supporting device and fixed.

[0018] The present invention also provides a multi-spectral temperature measurement reflected light characterization calibration method based on a heat flux sensor in a transient radiation heating environment. A spectral radiation brightness matrix calibration database of heater reflected light interference indexed by the heat flux sensor is established. During the test, the above database is read in real time according to the spatial heat flux value tested by the heat flux sensor, so that the heater reflected light interference can be obtained in real time. Combined with the spectral emissivity model of the material and the multi-spectral temperature measurement algorithm, the heater reflected light interference can be removed in real time in the algorithm, so that the real temperature of the structure can be obtained.

[0019] The beneficial effects of the present invention are as follows:

[0020] 1. Solved the problem of characterizing the interference of heater reflected light in transient radiation heating environment.

[0021] The spectral reflectivity of the designed water-cooled radiator is not less than 0.95. The high reflectivity can ensure that the radiation light from the heater will not cause a large temperature rise when projected onto the standard circular plate. In addition, the cooling of the standard circular plate by water-cooling and air-cooling devices can keep it at a low temperature even at high temperatures. Based on the spectral reflectivity of the water-cooled radiator and the spectral radiation brightness obtained by the multi-spectral thermometer, the heater radiation interference I under different spatial heat fluxes q can be calculated in real time.e (λ,T e ). After interpolation, qI is formed e (λ,T e ) calibration database, and then realize the characterization of heater reflected light interference in transient radiant heating environment.

[0022] 2. The problem of real-time correction of heater reflected light interference in transient radiation heating environment is solved.

[0023] During the test, the heat flow sensor is used as the index to query qI in real time. e (λ,T e ) calibration database, which can correct the interference of heater reflected light in real time, and combine the spectral emissivity model of the material and the multi-spectral radiation temperature measurement algorithm to solve the technical problem of inaccurate radiation temperature measurement in radiation heating environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of a multi-spectral temperature measurement reflected light characterization calibration device based on a heat flux sensor in a transient radiation heating environment;

[0025] Figure 2 It is a schematic diagram of the composition of the water-cooled radiator;

[0026] Figure 3 It is a schematic diagram of the bottom water cooling tooling;

[0027] Figure 4 This is a schematic diagram of a standard reflector and heat conducting sheet;

[0028] Figure 5 It is a schematic diagram of the water cooling tooling on the side;

[0029] Figure 6 This is a schematic diagram of the water-cooled radiator after assembly;

[0030] Figure 7 It is a flow chart of a multi-spectral temperature measurement reflected light characterization calibration method based on a heat flux sensor in a transient radiation heating environment;

[0031] Figure 8 It is a multi-spectral temperature measurement reflected light matrix calibration database based on heat flux sensors in transient radiation heating environments.

[0032] Including: 1 water-cooled radiator 1-1 bottom water-cooling tooling 1-1-1 bottom water-cooling tooling body 1-1-2 bottom water-cooling tooling water channel 1-1-3 bottom water-cooling tooling fixing plate 1-2 standard reflector 1-3 side water-cooling tooling 1-3-1 side water-cooling tooling body 1-3-2 side water-cooling tooling water channel 1-3-3 side water-cooling tooling fixing plate 1-3-4 side water-cooling tooling air hole 1-3-5 side water-cooling tooling air channel 1-4 thermal conductive sheet 2 multi-spectrum thermometer 3 heater 3-1 heater reflector 3-2 heating element 4 heat flow sensor 5 supporting device DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0034] This embodiment provides a multi-spectral temperature measurement in a radiation heating environment heater reflected light interference characterization calibration device, wherein the device composition schematic diagram is as follows Figure 1 As shown, the device includes: a water-cooled radiator 1, a multi-spectrum thermometer 2, a heater 3, a heat flux sensor 4 and a supporting device 5.

[0035] 1) Multi-spectral temperature measurement in radiation heating environment, heater reflected light interference characterization calibration device

[0036] like Figure 1 As shown, the water-cooled radiator 1 is embedded in the support device 5 and fixed, and is placed on the right side of the heater 3. The support device 5 is a flat plate made of the same material as the tested object, in order to maintain the same radiation environment as the formal test. Preferably, the support device 5 is a graphite flat plate.

[0037] The heater 3 is composed of a reflector 3-1 and a heating element 3-2, wherein the reflector 3-1 is the heating element and 3-2 provides support, and cooling water is passed into the reflector 3-1 to prevent damage due to high temperature. Preferably, the reflector 3-1 is made of stainless steel, and the heating element 3-2 is a quartz lamp or a graphite heating element.

[0038] The heat flow sensor 4 is mounted on the reflector plate 3-1 and is used to test the spatial heat flow of the heater 3. To prevent high temperature damage during the thermal test, the heat flow sensor 4 is usually designed as a water-cooled structure.

[0039] The multi-spectral thermometer 2 is placed on the left side of the heater 3 to obtain the spectral radiation brightness of the heater 3. Preferably, the multi-spectral thermometer 2 has a wavelength range of 1.1 μm-1.7 μm and 100 spectral channels.

[0040] 2) Water-cooled radiator 1

[0041] The water-cooled radiator 1 is used to test and analyze the spectral characteristics of the heater radiation brightness. The device is composed of Figure 2 As shown, it is composed of a bottom water cooling tooling 1-1, a standard reflection plate 1-2, a side water cooling tooling 1-3 and a heat conducting sheet 1-4.

[0042] The bottom surface water cooling tooling 1-1 schematic diagram is as follows Figure 3 As shown, it is composed of a bottom surface water cooling fixture body 1-1-1, a bottom surface water cooling fixture water channel 1-1-2 and a bottom surface water cooling fixture fixing plate 1-1-3. The bottom surface water cooling fixture body 1-1-1 is a conical body made of stainless steel, with a water cooling channel inside. The bottom surface water cooling fixture water channel 1-1-2 is installed on the rear end surface, connecting the cooling water inlet and outlet pipes, so that the standard reflector 1-2 maintains a low front surface temperature in a high-temperature radiation heating environment. The bottom surface water cooling fixture fixing plate 1-1-3 is made of stainless steel, with a mounting hole at both ends for fixing the standard reflector 1-2.

[0043] The standard reflector 1-2 is a high reflectivity circular plate, such as Figure 2 As shown, the material is ceramic or highly reflective metal, and its spectral reflectivity is not less than 0.95; preferably, the material is a gold-plated reflector, and its spectral reflectivity in the near infrared (wavelength 1μm-2μm) is about 0.95. The standard reflector 1-2 reflects the light intensity projected by the heater 3 onto its surface into the multi-spectral thermometer 2.

[0044] The schematic diagram of the side water cooling tooling 1-3 is as follows Figure 5As shown, it includes a side water-cooling tooling body 1-3-1 and a side water-cooling tooling water path 1-3-2, a side water-cooling tooling fixing plate 1-3-3, a side water-cooling tooling air hole 1-3-4 and a side water-cooling tooling air path 1-3-5. The side water-cooling tooling body 1-3-1 is a cylinder or a cube, with a hollow cone in the middle, made of stainless steel, and a side water-cooling tooling water path 1-3-2 is installed on the rear end face, connecting the cooling water inlet and outlet pipes, so that the standard reflector 1-2 maintains a low side end surface temperature in a high-temperature radiation heating environment. The side water-cooling tooling fixing plate 1-3-3 is made of stainless steel, and a mounting hole is opened at each end for fixing the standard reflector 1-2. The side water-cooling tooling air path 1-3-5 is connected to a low-temperature gas source, preferably a gas source after liquid nitrogen gasification. After being transmitted through the gas path 1-3-5, the low-temperature gas flows out from the air hole 1-3-4, sweeping the surface of the standard reflector 1-2 to remove particles in time. The low-temperature gas can also keep the surface of the standard reflector 1-2 at a relatively low temperature. The side water-cooling tooling gas path 1-3-4 is a porous structure made of stainless steel.

[0045] The heat conducting sheets 1-4 are made of silica gel material and are used to assist in heat dissipation.

[0046] The specific way of connecting the various parts of the water-cooled radiator 1 is as follows: the heat conducting sheet 1-4 is installed on the side of the standard reflector 1-2, the standard reflector 1-2 is placed on the inner end surface of the side water-cooling fixture 1-3, the bottom water-cooling fixture 1-1 and the side water-cooling fixture 1-3 are connected by nails through the holes on both sides to support the standard reflector 1-2, and the conical structure of the two water-cooling fixtures can fix the standard reflector 1-2 firmly without loosening. The schematic diagram of the water-cooled radiator after assembly is as follows Figure 6 shown.

[0047] The present invention also provides an embodiment, which provides a multi-spectral temperature measurement reflected light characterization calibration method based on a heat flux sensor in a transient radiation heating environment.

[0048] A spectral radiation brightness matrix calibration database of heater reflected light interference based on the heat flow sensor as the index is established. During the test, the above database is read in real time according to the spatial heat flow value tested by the heat flow sensor, and the heater reflected light interference can be obtained in real time. Combined with the spectral emissivity model of the material and the multi-spectral temperature measurement algorithm, the heater reflected light interference can be removed in real time in the algorithm, so that the real temperature of the structure can be obtained. The specific steps are as follows: Figure 7 shown.

[0049] 1) Device construction.

[0050] The water-cooled radiator is embedded in the supporting device and fixed, and is placed on the right side of the heater. The heat flux sensor is installed on the reflecting plate, and the multi-spectrum thermometer is placed on the left side of the heater.

[0051] 2) Characterization of heater reflected light interference

[0052] The same heat load as in the formal heat test is applied to both ends of the heater 3. The heat flux sensor 4 obtains the spatial heat flux q of the heater 3. The multi-spectral thermometer 2 obtains the spectral radiation brightness I reflected by the standard reflector 1-2 through the gap between the heating elements 3-2. ρ Since the water-cooled radiator 1 maintains a relatively low temperature under the cooling effect, its own radiation emission item I ε can be ignored, so the radiation brightness obtained by the radiation thermometer is: I = I ρ =ρ·I e (λ,T e ), where ρ is the spectral reflectivity of the standard circular reflector of the water-cooled radiator, which is a known quantity, λ is the wavelength, and T e is the temperature of the standard reflector. Thus, the radiation interference I of the heater 3 under different heat flow conditions can be calculated in real time. e (λ,T e ). After interpolation, the heat flux q-spectral radiance I with the heat flux sensor 4 as the index is formed e (λ,T e ) matrix calibration database, such as Figure 8 As shown, the interference of reflected light from the heater 3 is characterized.

[0053] 3) Heater reflected light interference calibration

[0054] Before the formal test, the water-cooled radiator 1 is replaced with the test piece and heated according to the above heat load. During the heating process, the heat flux data q measured by the heat flux sensor 4 and the radiation brightness I measured by the multi-spectral thermometer 2 are obtained in real time. At the same time, the measured heat flux data q reads qI e (λ,T e ) calibration database, and obtain the radiation brightness I of heater 3 e (λ,T e ), combined with the emissivity model in the prior art, the emissivity ε of the tested object is obtained, and according to formula (1),

[0055]

[0056] According to formula (2), the spontaneous radiation brightness of the target object I can be obtained: b , and further through the multi-spectral radiation temperature measurement algorithm, the real temperature of the target object can be obtained.

[0057] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-spectral temperature measurement reflected light characterization calibration device based on a heat flux sensor in a transient radiation heating environment, characterized in that: include: Water-cooled radiator, multi-spectral thermometer, heater, heat flux sensor and supporting device; The water-cooled radiator is used to test and analyze the spectral characteristics of the heater's radiation brightness, and is composed of a standard reflector, a heat conducting sheet, a bottom water-cooling tooling, and a side water-cooling tooling; The multi-spectral thermometer is used to obtain the spectral radiation brightness of the heater; The heater is composed of a reflective plate and a heating element; The supporting device is used for embedding the water-cooling radiator.

2. According to the multi-spectral temperature measurement reflected light characterization calibration device based on heat flux sensor in transient radiation heating environment in claim 1, it is characterized in that: The standard reflector is a high-reflectivity circular plate, and the spectral reflectivity is not less than 0.

95.

3. According to claim 1, a multi-spectral temperature measurement reflected light characterization calibration device based on a heat flux sensor in a transient radiation heating environment is characterized in that: The standard reflector is made of ceramic or highly reflective metal.

4. According to claim 3, a multi-spectral temperature measurement reflected light characterization calibration device based on a heat flux sensor in a transient radiation heating environment is characterized in that: The standard reflective plate has a high reflectivity characteristic.

5. According to claim 1, a multi-spectral temperature measurement reflected light characterization calibration device based on a heat flux sensor in a transient radiation heating environment is characterized in that: The heat flow sensor is a water-cooled structure.

6. The multi-spectral temperature measurement reflected light characterization calibration device based on a heat flux sensor in a transient radiation heating environment according to claim 1, characterized in that: The supporting device is a graphite flat plate.

7. The multi-spectral temperature measurement reflected light characterization calibration device based on a heat flux sensor in a transient radiation heating environment according to claim 1, characterized in that: The bottom surface water cooling tooling is composed of a bottom surface water cooling tooling body, a bottom surface water cooling tooling water channel and a bottom surface water cooling tooling fixing plate. The bottom surface water cooling tooling body is a cone-shaped body made of stainless steel, with a water cooling channel inside, and a bottom surface water cooling tooling water channel is installed on the rear end surface.

8. The multi-spectral temperature measurement reflected light characterization calibration device based on a heat flux sensor in a transient radiation heating environment according to claim 1, characterized in that: The side water-cooling tooling consists of a side water-cooling tooling body, a side water-cooling tooling water channel, a side water-cooling tooling fixing plate, a side water-cooling tooling air hole and a side water-cooling tooling air channel. The side water-cooling tooling body is a cylinder or a cube with a hollow cone in the middle. It is made of stainless steel, and the side water-cooling tooling water channel is installed on the rear end face.

9. The multi-spectral temperature measurement reflected light characterization calibration device based on a heat flux sensor in a transient radiation heating environment according to claim 1, characterized in that: The supporting device and the water-cooling radiator are placed on one side of the heater, the heat flux sensor is installed on the reflecting plate, and the multi-spectrum temperature meter is placed on the other side of the heater.

10. A multi-spectral temperature measurement reflected light characterization calibration method based on the multi-spectral temperature measurement reflected light characterization calibration device based on a heat flux sensor in a transient radiation heating environment according to any one of claims 1 to 9, characterized in that: The following steps are involved: 1) Characterization of heater reflected light interference: Apply the same heat load as the formal thermal test at both ends of the heater, the heat flux sensor obtains the heat flux q of the heater, and the multi-spectral thermometer obtains the spectral radiation brightness I of the standard reflector through the gap between the heaters ρ , by I ρ =ρ·I e (λ,T e ) can calculate the heater radiation interference brightness I under different spatial heat fluxes in real time e (λ,T e ), where ρ is the spectral reflectance of the standard reflector, λ is the wavelength, T e is the temperature of the standard reflector; after interpolation, qI is formed with the heat flux sensor as the index e (λ,T e ) Matrix calibration database; 2) Heater reflected light calibration: Before the formal test, the water-cooled radiator is replaced with the test piece and heated according to the above heat load; during the heating process, the heat flux q and the radiation brightness I measured by the multi-spectral thermometer are obtained in real time; at the same time, qI is read according to the measured heat flux q e (λ,T e ) matrix calibration database, and obtain I e (λ,T e ), according to the formula Get the spontaneous radiation brightness I of the tested object b , where ε is the spectral emissivity of the test piece; further through the multi-spectral radiation temperature measurement algorithm, the real temperature of the test piece can be obtained.

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