JP2014206418A - Temperature measurement device and temperature measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the influence of both spray and rubber dispersion when the surface temperature of a high-temperature body is measured while cooling water is injected.SOLUTION: The temperature measurement device 11 of the present invention includes: first imaging means 10afor imaging a high-temperature body using first measuring light; second imaging means 10afor imaging the high-temperature body using second measuring light; temperature converting means 12a for converting the luminance of an image picked up by each of the first imaging means 10aand second imaging means 10ainto the surface temperature of the high-temperature body; and calibrating means 12b for calibrating the first surface temperature distribution converted from the luminance of the image picked up by the first imaging means 10ausing a second surface temperature distribution converted from the luminance of the image picked up by the second imaging means 10a.

Description

  The present invention relates to a temperature measuring device and a temperature measuring method.

  In a manufacturing process at a steelworks, there are many processes for monitoring temperature during cooling while injecting cooling water onto a high-temperature body such as a product. For example, slab cooling in a continuous casting process is a typical example, and the surface temperature of the slab during cooling greatly affects the quality of the product. Therefore, in the continuous casting process, the temperature distribution over the entire surface of the slab surface is an important monitoring item, and highly accurate temperature measurement is required over the entire surface of the slab surface.

  As a method for measuring the surface temperature of a high-temperature object, a contact-type method in which a thermocouple or the like is brought into contact with the surface of the object and radiation energy (infrared rays) radiated from the object using a radiation thermometer or the like Two types are mainly known, a non-contact method that is performed by detecting. Of these, the contact method is difficult to apply when the object to be measured moves like a slab during continuous casting. Therefore, a radiation thermometer is used to measure the surface temperature of the slab. It is common. A thermography is mentioned as a typical radiation thermometer.

  However, when such a radiation thermometer is used for measuring the temperature of the slab surface, the cooling water sprayed to cool the slab becomes water smoke, and the water smoke hinders measurement by the radiation thermometer. In addition, the cooling water remains on the surface of the slab and forms a so-called water paste, which causes scattering and absorption of infrared rays, resulting in a problem that the measurement accuracy of the surface temperature is lowered.

  In order to solve this kind of problem, various proposals have been made so far. For example, a measuring method (see Patent Document 1) in which a water column as an optical waveguide is formed between a measurement object and a radiation thermometer and radiated light is detected through the water column, or an optical system using an optical fiber. There is a measurement method (refer to Patent Document 2) in which the effect of cooling water or steam is eliminated by injecting gas into the measurement region while bringing the measurement object closer to the measurement object.

JP 2008-164626 A JP 2012-071330 A

  However, since the conventional technology as described above requires a special apparatus configuration and is a method of measuring one point in the measurement object, the temperature distribution is acquired over the entire surface of the slab. Requires a separate scanning device. Therefore, in the conventional technology as described above, the configuration of the apparatus is complicated, and there is a possibility that an accident of contact between the measurement object and the measurement apparatus may occur during operation. Therefore, it cannot be said that the prior art as described above has sufficiently solved the problem of smoke and water when measuring the surface temperature of the hot body while jetting cooling water.

  The present invention has been made in view of the above, and its purpose is to reduce the influence of both smoke and water when measuring the surface temperature of a hot body while jetting cooling water. It is in providing a measuring device and a temperature measuring method.

  In order to solve the above-described problems and achieve the object, a temperature measurement device according to the present invention is a temperature measurement device that measures the surface temperature of a hot body while injecting cooling water, and has a wavelength of 0.85 μm to 1. A first imaging means for imaging the high temperature body using a first measurement light belonging to a range of 0.0 μm, and a second imaging means for imaging the high temperature body using a second measurement light belonging to a wavelength range of 8 μm to 12 μm. A temperature converting means for converting the brightness of each image picked up by the first image pick-up means and the second image pick-up means into a surface temperature of the high-temperature body, and a conversion from the brightness of the image picked up by the second image pick-up means. The second surface temperature distribution is used to calibrate the first surface temperature distribution converted from the luminance of the image captured by the first imaging unit.

  In order to solve the above-described problems and achieve the object, a temperature measurement method according to the present invention is a temperature measurement method for measuring the surface temperature of a hot body while jetting cooling water, and has a wavelength of 0.85 μm to 1. A first imaging step for imaging the high temperature body using a first measurement light belonging to a range of 0.0 μm, and a second imaging step for imaging the high temperature body using a second measurement light belonging to a wavelength range of 8 μm to 12 μm. A temperature conversion step of converting the brightness of each image captured in the first imaging step and the second imaging step into a surface temperature of the high temperature body; and an image captured using the second measurement light And a calibration step of calibrating the first surface temperature distribution converted from the luminance of the image captured using the first measurement light using the second surface temperature distribution converted from the luminance. .

  The temperature measuring device and the temperature measuring method according to the present invention have an effect that it is possible to reduce the influence of both smoke and water when measuring the surface temperature of a high temperature body while jetting cooling water.

FIG. 1 is a schematic view showing a continuous casting machine to which a temperature measuring device according to an embodiment of the present invention is applied. FIG. 2 is an enlarged schematic configuration diagram of two adjacent roll segments in the continuous casting machine. FIG. 3 is a schematic configuration diagram of a roll segment observed from the direction in which the slab is conveyed. FIG. 4 is a block diagram showing a schematic configuration of the temperature measuring apparatus according to the embodiment of the present invention. FIG. 5 is a graph showing correspondence data between the surface temperature of the slab and the luminance of the image. FIG. 6 is a conceptual diagram showing a mechanism for reconstructing the temperature distribution. FIG. 7 is a flowchart showing the procedure of the temperature measurement method according to the embodiment of the present invention. FIG. 8 is a graph showing an absorption spectrum of liquid water. FIG. 9 is a graph showing Planck's radiation law. FIG. 10 is an image obtained by imaging a slab using measurement light having a wavelength of 0.85 μm to 1.0 μm. FIG. 11 is an image obtained by imaging a slab using measurement light having a wavelength of 8 μm to 12 μm. FIG. 12 is a graph of an image and temperature distribution obtained by reconstructing the verification experiment into a two-dimensional image. FIG. 13 is a graph showing a temperature distribution after calibration using the temperature measurement device and the temperature measurement method according to the embodiment of the present invention.

  Hereinafter, a temperature measuring device and a temperature measuring method according to an embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments described below. In the following description, an embodiment in which the present invention is applied to measurement of the surface temperature distribution of a slab during continuous casting is used. However, the present invention is not limited to this embodiment, and cooling water is injected into a hot body. However, it can be used when measuring the surface temperature.

[Temperature measuring device]
FIG. 1 is a schematic view showing a continuous casting machine 1 to which a temperature measuring device according to an embodiment of the present invention is applied. As shown in FIG. 1, a continuous casting machine 1 according to an embodiment of the present invention gradually adds a tundish 3 into which molten steel 2 is injected and molten steel 2 poured from the tundish 3 through an immersion nozzle 4. A copper mold 5 to be cooled and a plurality of rolls 7 for conveying a semi-solid cast piece 6 drawn from the mold 5 are provided. A plurality of rolls 7 provided in the continuous casting machine 1 are unitized into a plurality of roll segments 8.

  While the slab 6 cast by the continuous casting machine 1 is continuously conveyed by the plurality of rolls 7, cooling water is jetted by the cooling nozzle and cooled under appropriate temperature control.

  FIG. 2 is a schematic configuration diagram in which two adjacent roll segments 8 in the continuous casting machine 1 are enlarged, and FIG. 3 is a schematic configuration diagram of the roll segments 8 observed from the conveying direction of the slab 6. 2 and 3, the roll segment 8 includes an upper roll 7a that supports the slab 6 from the side opposite to the reference surface (upper surface side) and a lower roll 7b that supports the slab 6 from the reference surface side (lower surface side). The upper frame 9a and the lower frame 9b that hold the plurality of upper rolls 7a and lower rolls 7b are mainly configured.

  The temperature measuring device according to the embodiment of the present invention measures the surface temperature of the slab 6 by using, for example, a gap between two roll segments 8. As shown in FIGS. 2 and 3, in the temperature measuring device according to the embodiment of the present invention, the imaging means 10 a and 10 b are arranged near the gap between the two roll segments 8, and the imaging means 10 a and 10 b pass through the gap. Then, the surface temperature of the slab 6 is measured.

  Further, when measuring the surface temperature of the anti-reference surface of the slab 6, the imaging means 10 a and 10 b are disposed obliquely above both sides of the slab 6 as shown in FIG. 3. This is to prevent water smoke rising from the slab 6 from directly affecting the imaging means 10a and 10b.

  For example, as shown in FIG. 3, the imaging units 10 a and 10 b have an angle of 40 degrees with the front end surface of the slab 6 when the imaging units 10 a and 10 b are used as a reference, and the rear end surface. It is arranged at a position where the angle formed is 65 degrees. Therefore, the imaging means 10a and 10b are disposed at a height of 1.8 m above the anti-reference surface of the slab 6.

  As will be described in detail later, each of the imaging units 10a and 10b includes a first imaging unit and a second imaging unit. The first imaging unit and the second imaging unit may be configured as separate cameras or the like, or may be physically configured as one device by internally branching the optical path.

  In the continuous casting machine 1 to which the temperature measuring device according to the embodiment of the present invention is applied, an appropriate roll segment 8 is selected from the plurality of roll segments 8 provided as described above, and the gap between the roll segments 8 is selected. The imaging means 10a and 10b are arranged in the above.

  FIG. 4 is a block diagram showing a schematic configuration of the temperature measuring apparatus according to the embodiment of the present invention. In the following description, for the sake of simplicity, the configuration relating to the imaging means 10a among the imaging means 10a and 10b arranged on both sides of the slab 6 will be described, but the configuration relating to the imaging means 10b is also the same. ing.

  As shown in FIG. 4, the temperature measurement device 11 according to the embodiment of the present invention is roughly composed of an imaging unit 10 a and an image processing unit 12. Furthermore, the temperature measurement device 11 according to the embodiment of the present invention preferably includes an output unit 13 for outputting the output of the image processing unit 12.

As described above, the imaging unit 10a includes a first image pickup means 10a ₁ and second imaging means 10a ₂ therein. The first image pickup means 10a ₁ and the second imaging unit 10a _2, respectively may be constructed as a separate camera or the like, or be physically one apparatus structure by branching the optical path within the Is possible.

The first imaging means 10a ₁ is an imaging device for imaging the surface of the slab 6 using first measurement light belonging to a wavelength range of 0.85 μm to 1.0 μm. On the other hand, the second imaging means 10a ₂ is an imaging device for imaging the surface of the slab 6 by using the second measurement light belonging to the wavelength range of 8Myuemu～12myuemu. That is, the first image pickup means 10a ₁ and the second imaging unit 10a _2, can be constructed by respectively providing the desired filter lens separate camera. Further, the first imaging unit 10a ₁ and the second imaging unit 10a _2, can also be configured by providing a desired filter by the optical path branching one camera optical system with the half mirror or the like.

Data of the image by the first imaging unit 10a ₁ and the second imaging unit 10a ₂ are captured are transmitted independently to the temperature converting unit 12a of the image processing unit 12.

The image processing unit 12 is an image processing apparatus including a temperature conversion unit 12a and a calibration unit 12b. Temperature converting means 12a is a means for the first imaging unit 10a ₁ and the second imaging unit 10a ₂ converts the luminance of each image captured in the surface temperature of the slab 6, for example, is implemented by a computer program.

  For example, as shown in FIG. 5, the temperature conversion unit 12 a includes correspondence data between the surface temperature of the slab 6 and the luminance of the image, and converts the input image luminance to the surface temperature of the slab 6. It can be. The correspondence data as shown in FIG. 5 can be acquired by measuring the relationship between temperature and luminance in advance using, for example, a black body furnace.

  Moreover, the relationship between the brightness | luminance X and the temperature T can be simply expressed like the following formula 1 using the constants A and B. Therefore, the temperature conversion means 12a may be configured to convert the luminance of the input image into the surface temperature of the slab 6 using the following formula 1.

The calibration unit 12b is a unit that calibrates the first surface temperature distribution using the second surface temperature distribution, and is realized by, for example, a computer program. Here, the second surface temperature distribution is a temperature distribution temperature converter 12a from the luminance of the image by the second imaging means 10a ₂ is captured is obtained by converting, the first surface temperature distribution, the first imaging It means 10a ₁ is a temperature distribution that the temperature converting means 12a is obtained by converting the brightness of the captured image.

  That is, the calibration means 12b uses the second surface temperature distribution acquired using the second measurement light belonging to the wavelength range of 8 μm to 12 μm, and the first measurement light belonging to the wavelength range of 0.85 μm to 1.0 μm. The second surface temperature distribution acquired by using is calibrated.

  As a calibration method performed by the calibration unit 12b, for example, a method of calibrating the first surface temperature distribution so that the representative value of the second surface temperature distribution matches the representative value of the first surface temperature distribution is conceivable. As a representative value used in the calibration, it is conceivable to use an average value of temperature distribution. However, other values such as a maximum value, a median value, or a mode value can also be used.

  Further, the temperature distribution range for determining the representative value may be a one-dimensional region or a two-dimensional region. In the case of a pair of objects to be measured such as a slab 6 cast by the continuous casting machine 1, the temperature distribution range for determining the representative value is a one-dimensional region such as the width of the slab 6. However, even in the case of an object to be measured while being transported, a two-dimensional region can be obtained by appropriately classifying according to the transport speed.

  When the average value of the temperature distribution in the entire width range of the slab 6 is used as the representative value, the calibration means 12b has the average value of the first surface temperature distribution and the average value of the second surface temperature distribution in the entire width range of the slab 6. Will be calibrated to match. Specifically, the calibration unit 12b applies the correction coefficient obtained by dividing the average value of the second surface temperature distribution by the average value of the first surface temperature distribution to the first surface temperature distribution to thereby obtain the first surface temperature distribution. Calibrate the temperature distribution.

  The first surface temperature distribution calibrated by the calibration unit 12b as described above is output by the output unit 13. For example, the output means 13 is a screen display device, and presents information to the operator of the continuous casting machine 1 by displaying the temperature distribution of the slab 6 calibrated as an image, a graph, or a numerical value.

  Further, when the temperature measurement is performed by dividing an object to be measured such as a slab 6 cast by the continuous casting machine 1 into a one-dimensional region, the output means 13 is a one-dimensional region. It has the function of reconstructing the obtained temperature distribution into the temperature distribution of the entire surface of the slab 6.

  FIG. 6 is a conceptual diagram showing a mechanism for reconstructing the temperature distribution by the output means 13. As shown in FIG. 6, the slab 6 cast by the continuous casting machine 1 is blocked by the upper frame 9a of the roll segment 8, and only a part can be measured from the gap. Therefore, the imaging means 10a measures a one-dimensional region in the width direction of the surface of the slab 6 or a two-dimensional region close thereto through this gap. Then, the measurement data measured by the imaging unit 10a is processed by the image processing unit as described above and converted into a temperature distribution corresponding to the measurement region.

  Here, since the slab 6 cast by the continuous casting machine 1 is transported and moved between the roll segments 8, the measurable region from the gap between the roll segments 8 also moves every moment. Accordingly, the output means 13 reconstructs the temperature distribution on the surface of the slab 6 by arranging the measurement ranges of the one-dimensional region or a two-dimensional region close thereto in the time axis direction. Then, the output unit 13 displays the reconstructed temperature distribution on the screen.

[Temperature measurement method]
Next, the temperature measurement method according to the embodiment of the present invention will be described. Hereinafter, the temperature measurement method according to the embodiment of the present invention will be described with reference to the configuration of the temperature measurement device according to the embodiment of the present invention. However, the implementation of the temperature measurement method according to the embodiment of the present invention will be described below. It is not limited by the configuration of

FIG. 7 is a flowchart showing the procedure of the temperature measurement method according to the embodiment of the present invention. As shown in FIG. 7, in the temperature measurement method according to the embodiment of the present invention, the first imaging means 10a ₁ is _first cast using the first measurement light belonging to the wavelength range of 0.85 μm to 1.0 μm. 6 is imaged (step S1).

The second imaging unit 10a ₂ is to image the billet 6 by using the second measurement light belonging to the wavelength range of 8Myuemu～12myuemu (step S2). In the temperature measurement method according to the embodiment of the present invention, step S1 and step S2 may be performed in order or may be executed simultaneously.

  Next, in the temperature measurement method according to the embodiment of the present invention, the temperature conversion means 12a of the image processing unit 12 sets the brightness of each image captured using the first measurement light and the second measurement light to the cast piece 6. (Step S3). As described above, the conversion process performed by the temperature conversion unit 12a of the image processing unit 12 employs a method using corresponding data measured in advance or a method using a conversion formula.

  In the temperature measurement method according to the embodiment of the present invention, the calibration unit 12b of the image processing unit 12 obtains the first measurement light using the second surface temperature distribution obtained using the second measurement light. The first surface temperature distribution is calibrated (step S4). As described above, the calibration method performed by the calibration unit 12b of the image processing unit 12 is, for example, the first surface temperature distribution so that the representative value of the second surface temperature distribution matches the representative value of the first surface temperature distribution. It is possible to calibrate. Further, it is conceivable that the representative value used in the calibration is an average value of the temperature distribution. Specifically, the calibration unit 12b applies the correction coefficient obtained by dividing the average value of the second surface temperature distribution by the average value of the first surface temperature distribution to the first surface temperature distribution to thereby obtain the first surface temperature distribution. Calibrate the temperature distribution.

  The temperature measurement method according to the embodiment of the present invention described above is continuously repeated until the entire measurement range is covered. Moreover, the temperature distribution acquired by the temperature measuring method according to the embodiment of the present invention is appropriately reconstructed by the output means 13 and displayed on the screen.

[Function and effect]
Hereinafter, the effect of the temperature measuring device and the temperature measuring method according to the embodiment of the present invention described above will be described with reference to experimental results.

  The main obstacles to the temperature measurement of the slab are the aforementioned smoke and water. Smoke is visualized as very small water droplets by cooling water vapor, water glue is the cooling water remaining on the slab, and both smoke and water become liquid water. ing.

  8 is a graph showing the absorption spectrum of liquid water (published from BUNSEKI KAGAKA VOL. 60, No. 1, pp. 19-31 (2011)). The horizontal axis in FIG. 8 represents the wavelength of the absorbed light (electromagnetic wave), the vertical axis represents the light (electromagnetic wave) absorbance, and the lower the graph is, the more light (electromagnetic wave) is transmitted. doing.

  As shown in FIG. 8, light having a wavelength of about 400 nm to 1000 nm (1.0 μm) that is visible light is well transmitted through liquid water. On the other hand, infrared rays having a wavelength of around 10 μm (for example, 8 μm to 12 μm) are absorbed by liquid water.

  Accordingly, the inventors of the present invention conducted an experiment in which a long pass filter that transmits light having a wavelength longer than 0.85 μm was installed in front of the CCD camera to image the slab from between the roll segments. Since the CCD camera used has a sensitivity of 400 nm to 1.0 μm, imaging is performed using measurement light having a wavelength of 0.85 μm to 1.0 μm by using the above filter.

  Here, the reason why the filter having a wavelength of 0.85 μm or less is used is as follows. First, the assumed temperature of the slab is in the range of about 700 ° C to 900 ° C. The light (electromagnetic wave) radiated from the substance in this temperature range contains a lot of infrared rays having a wavelength of 0.85 μm or more according to Planck's radiation law (see FIG. 9). For this reason, in the temperature measurement in this temperature range, measurement light having a wavelength of 0.85 μm or more can be used so that it can be accurately measured without being affected by external light noise.

  FIG. 10 is an image obtained by imaging a slab using measurement light having a wavelength of 0.85 μm to 1.0 μm. The images in FIGS. 10A and 10B are obtained by capturing the same slab at different timings, and FIG. 10A is an image captured at a timing when no water smoke is generated. ) Is an image captured at the timing when water smoke is generated.

  Since the images of (a) and (b) in FIG. 10 are images obtained by imaging the same slab, the surface temperature of the slab can be regarded as almost the same, but (a) and (b) in FIG. As can be seen from the comparison of (), in fact, the brightness of the image captured at the timing when the smoke is generated is greatly reduced.

  In this experiment, even if the slab is imaged using measurement light with a wavelength of 0.85 μm to 1.0 μm, which should have a high water transmittance, the brightness of the captured image decreases when smoke is generated. Is meant to do.

  The inventors of the present invention have confirmed that the diameter of the water droplets in the smoke is distributed in the range of 1 μm to 10 μm by further investigation thereafter. Then, the inventors have come to the conclusion that the phenomenon that the brightness of the image is lowered when measuring light having a wavelength of 0.85 μm to 1.0 μm is caused by Mie scattering caused by water droplets in the smoke. In Mie scattering, the scattering intensity increases in proportion to the reciprocal of the wavelength. For this reason, measurement light having a short wavelength of about 1 μm is very strongly scattered by Mie scattering.

  In order to verify the above conclusion, the inventors of the present invention conducted an experiment similar to the experiment shown in FIG. 10 using a thermo viewer having a sensitivity in the wavelength range of 8 μm to 12 μm.

  FIG. 11 is an image obtained by imaging a slab using measurement light having a wavelength of 8 μm to 12 μm. Images (a) and (b) in FIG. 11 are images of the same slab taken at different timings. (A) is an image taken at a timing when no water smoke is generated. ) Is an image captured at the timing when water smoke is generated.

  Since the images in FIGS. 11A and 11B are images of the same slab, the surface temperature of the slab can be regarded as almost the same. Unlike the experiment shown in FIG. 10, the average brightness of the whole image is substantially the same in the comparison of the images shown in FIGS.

  Note that the spots appearing in the images of FIGS. 11A and 11B are water on the slab. The measurement light used in this experiment has a wavelength of 8 μm to 12 μm, and has a low transmittance for liquid water. As a result, it is easy to be greatly affected by the water on the slab, and in the images of FIGS. 11A and 11B, the water appears as spots.

  FIG. 12 is a graph of an image and temperature distribution obtained by reconstructing the verification experiment into a two-dimensional image. (A-1) in FIG. 12 is a surface luminance image of a slab imaged using measurement light having a wavelength of 8 μm to 12 μm using a thermo viewer, and (b-1) is a long path having a wavelength of 0.85 μm. It is the surface brightness | luminance image of the slab imaged using the measurement light of wavelength 0.85 micrometer-1 micrometer using the CCD camera which attached the filter. Both (a-1) and (b-1) of FIG. 12 show the one-dimensional area on the surface of the slab imaged through the gap between the roll segments by the method described with reference to FIG. Reconstructed as a surface luminance image.

  (A-2) and (b-2) in FIG. 12 are transverse profiles of the temperature distribution at the positions of the broken lines in the images (a-1) and (b-1), respectively. The positions of broken lines (1) to (6) in the images of (a-1) and (b-1) in FIG. 12 are the lines (1) to (6) of (a-2) and (b-2). It corresponds to the kind of graph. That is, in the graphs (a-2) and (b-2), the graphs with the same number of line types correspond to the temperature distribution at the same position of the slab.

  As can be seen from the comparison of the graphs of (a-2) and (b-2) in FIG. 12, temperature measurement using measurement light with a wavelength of 0.85 μm to 1 μm and temperature measurement using measurement light with a wavelength of 8 μm to 12 μm. So there is a significant difference.

  In the graph of (a-2) in FIG. 12, there is a portion where the temperature is reduced outside the frame, but in the graph of (b-2), there is no portion where the temperature is decreased outside the frame. The place where the temperature is reduced to the outside of the frame seen in the graph of (a-2) in FIG. 12 is an affected place of water on the slab.

  In addition, in the graph of (b-2) in FIG. 12, an overall decrease in temperature distribution is seen as in the graphs of line types (5) and (6), but in the graph of (a-2), this There is no overall decrease in temperature distribution. As shown in the graph of (b-2) in FIG. 12, the part where the temperature distribution is entirely lowered is the influence part of the water smoke.

  In the temperature measurement device and the temperature measurement method according to the embodiment of the present invention, the temperature measurement using the measurement light having the wavelength of 0.85 μm to 1 μm and the temperature measurement using the measurement light having the wavelength of 8 μm to 12 μm are remarkable. The temperature distribution is calibrated to reduce the effects of both smoke and water by taking advantage of the differences in characteristics. That is, the temperature measuring device and the temperature measuring method according to the embodiment of the present invention use the temperature distribution obtained by using the measuring light having a wavelength of 8 μm to 12 μm, which is less affected by water smoke, and have a wavelength 0 which is less affected by water. By calibrating the temperature distribution obtained using measuring light of .85 μm to 1 μm, the effects of both smoke and water are reduced.

  FIG. 13 is a graph showing a temperature distribution after calibration using the temperature measurement device and the temperature measurement method according to the embodiment of the present invention. The line types (1) to (6) in the graph shown in FIG. 13 are the line types (1) to (6) in the graphs shown in (a-2) and (b-2) in FIG. It corresponds to. Therefore, the temperature distribution shown in FIG. 13 is obtained by using the temperature measuring device and the temperature measuring method according to the embodiment of the present invention, and the surface of the slab shown in (a-1) and (b-1) of FIG. The temperature distribution in the broken line position of (1)-(6) in the image is shown.

  Specifically, the temperature distribution shown in FIG. 13 was calculated as follows.

First, an average value of one-dimensional surface temperature distribution obtained using the measuring light having a wavelength in the range of 8Myuemu～12myuemu, which is referred to as M _2. However, in the one-dimensional surface temperature distribution obtained using the measurement light in the wavelength range of 8 μm to 12 μm, a significant temperature drop occurs due to the influence of water, so that it is the lower limit value of the assumed temperature range of the slab 500 The average value is calculated by rejecting the value below the degree.

On the other hand, the average value of the one-dimensional surface temperature distribution acquired using the measurement light having a wavelength of 0.85 μm to 1 μm is calculated, and this is defined as M ₁ .

Then, by multiplying the average value M ₂ of the correction coefficient α determined by dividing the average value M ₁ to a one-dimensional surface temperature distribution obtained using the measuring light having a wavelength 0.85Myuemu～1myuemu, first surface temperature distribution Calibrate.

  FIG. 13 shows the temperature distribution obtained by performing the above calculation at the broken line positions (1) to (6) in the surface image of the slab shown in (a-1) and (b-1) of FIG. FIG.

  As can be seen from the graph of temperature distribution shown in FIG. 13, according to the temperature measuring device and the temperature measuring method according to the embodiment of the present invention, it is possible to reduce the influence of both water smoke and water glue.

  As described above, the temperature measuring device and the temperature measuring method according to the embodiment of the present invention have been described, but the embodiment of the present invention is not limited to the above embodiment. For example, the wavelength range of the first measurement light is limited to a wavelength range of 0.895 μm to 0.905 μm, or the wavelength range of the second measurement light is limited to a wavelength range of 9.5 μm to 10.5 μm. For example, the present invention can be appropriately implemented.

DESCRIPTION OF SYMBOLS 1 Continuous casting machine 2 Molten steel 3 Tundish 4 Immersion nozzle 5 Mold 6 Cast piece 7 Roll 8 Roll segment 9a Upper frame 9b Lower frame 10a, 10b Imaging means 10a ₁ 1st imaging means 10a ₂ 2nd imaging means 11 Temperature measuring device 12 Image processing unit 12a Temperature conversion means 12b Calibration means 13 Output means

Claims (8)

A temperature measuring device that measures the surface temperature of a hot body while injecting cooling water,
First imaging means for imaging the high temperature body using first measurement light belonging to a wavelength range of 0.85 μm to 1.0 μm;
Second imaging means for imaging the high temperature body using second measurement light belonging to a wavelength range of 8 μm to 12 μm;
Temperature conversion means for converting the brightness of each image captured by the first imaging means and the second imaging means into the surface temperature of the high temperature body;
Calibration means for calibrating the first surface temperature distribution converted from the brightness of the image captured by the first imaging means, using the second surface temperature distribution converted from the brightness of the image captured by the second imaging means; ,
A temperature measuring device comprising:   2. The temperature according to claim 1, wherein the calibration unit calibrates the first surface temperature distribution so that a representative value of the second surface temperature distribution matches a representative value of the first surface temperature distribution. measuring device.   The temperature measuring apparatus according to claim 2, wherein the representative value is an average value of a temperature distribution.   The calibration means multiplies the first surface temperature distribution by a correction coefficient obtained by dividing the average value of the second surface temperature distribution by the average value of the first surface temperature distribution, thereby obtaining the first surface temperature distribution. The temperature measuring device according to claim 1, wherein the distribution is calibrated. A temperature measurement method for measuring the surface temperature of a hot body while injecting cooling water,
A first imaging step of imaging the high temperature body using first measurement light belonging to a wavelength range of 0.85 μm to 1.0 μm;
A second imaging step of imaging the high temperature body using second measurement light belonging to a wavelength range of 8 μm to 12 μm;
A temperature conversion step of converting the brightness of each image captured in the first imaging step and the second imaging step into a surface temperature of the high temperature body;
The first surface temperature distribution converted from the luminance of the image captured using the first measurement light using the second surface temperature distribution converted from the luminance of the image captured using the second measurement light. A calibration step to calibrate,
A temperature measuring method comprising:   The temperature according to claim 5, wherein the calibration step calibrates the first surface temperature distribution so that a representative value of the second surface temperature distribution matches a representative value of the first surface temperature distribution. Measuring method.   The temperature measurement method according to claim 6, wherein the representative value is an average value of a temperature distribution.   In the calibration step, the first surface temperature distribution is obtained by multiplying the first surface temperature distribution by a correction coefficient obtained by dividing the average value of the second surface temperature distribution by the average value of the first surface temperature distribution. 6. The temperature measuring method according to claim 5, wherein the distribution is calibrated.