JP2009236898A - Radiation temperature measuring device and radiation temperature measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation temperature measuring device and a radiation temperature measuring method, capable of measuring even the temperature of a temperature measuring object being a melt unspecified in advance in accurate emissivity in a noncontact state, such as molten slag included in molten pig iron, for example, from a blast furnace. <P>SOLUTION: This radiation temperature measuring device 100 is provided for measuring the temperature of the temperature measuring object being the melt unspecified in advance in emissivity and transmitting at least a part of the heat emitted light. This radiation temperature measuring device 100 has an imaging part 110 for imaging the distribution of heat emitted luminance of the temperature measuring object, a highest luminance detecting part 123 for detecting the highest luminance in a pickup image imaged by the imaging part 110, and a temperature calculating part 124 for calculating the temperature of the temperature measuring object based on the highest luminance detected by the highest luminance detecting part 123. This radiation temperature measuring device 100 can measure even the temperature of the temperature measuring object unspecified in the accurate emissivity. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a radiation temperature measurement device and a radiation temperature measurement method for measuring a temperature of a temperature measurement object, which is a melt that transmits at least a part of heat radiation light, and whose emissivity is not specified in advance.

  The temperature measuring device for measuring the temperature of the temperature measuring object is roughly divided into a contact type and a non-contact type. Examples of the contact-type temperature measuring device include various types of temperature measuring devices such as a thermocouple type, a resistance type, and a liquid column type. These contact-type temperature measuring devices often use heat conduction and need to be in direct contact with the temperature measurement object. Therefore, for example, when a high temperature temperature measurement object is used for temperature measurement, the heat resistance of the contact type temperature measurement device is required.

  However, for example, as a molten material in which a plurality of substances are mixed such as molten iron flowing out from the blast furnace outlet at the steel works (molten pig iron taken out from the blast furnace) and molten slag (molten oxide taken out together with the molten iron) When the temperature measurement object is very high temperature, it is difficult to ensure heat resistance against such high temperature. Therefore, even if the temperature can be measured, the temperature sensing part of the contact-type temperature measuring device is often thermally damaged and cannot be used continuously, and it is difficult to perform continuous temperature measurement. However, the temperature in the furnace is reflected in the temperature of the molten iron and molten slag, and measuring the temperature of the molten iron and molten slag is an important index for judging the operating state of the blast furnace. In various industrial fields other than the iron making process, a temperature measuring device that can measure a high temperature temperature measuring object and can be used continuously or repeatedly is desired.

  Therefore, Patent Document 1 discloses a temperature measuring device that can measure the temperature of a temperature measurement object in a non-contact manner. This non-contact temperature measuring device measures the temperature of the temperature measurement object by observing the thermal radiance of the heat radiation emitted from the melt in which a plurality of substances to be temperature measurement are mixed. In temperature measurement using thermal radiation, the emissivity of the temperature measurement object is important. Therefore, this patent document 1 extracts the brightness of hot metal having a known emissivity from a picked-up image obtained by imaging a temperature measurement object with an imaging device having a high-speed shutter and separated from the hot metal part. We have succeeded in measuring the temperature of hot metal from

JP 2006-119110 A

  However, molten slag contains different emissivities such as silica, alumina, lime, etc. at unknown ratios, and the molten slag itself can be treated as one of the mixtures, and it is difficult to specify the emissivity of this molten slag. . Therefore, in the radiation temperature measuring device described in Patent Document 1, although the temperature of the hot metal with which the emissivity is known can be measured, the exact emissivity is not known because the exact emissivity such as molten slag is not known. It is difficult to accurately measure the temperature of the temperature measurement object that is not specified in advance. Also, the hot metal and molten slag, or the material mixed in the molten slag is non-uniformly turbid, and the surface is not flat, such as when leaving the blast furnace, and the surface is significantly undulated. Under certain conditions, the instantaneous wave shape affects the apparent emissivity, which may make it difficult to measure the hot metal temperature.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to specify an accurate emissivity in advance, for example, molten slag contained in the slag flow from the blast furnace. It is to measure the temperature of the temperature measurement object that is not melted in a non-contact manner.

  In order to solve the above-described problem, according to an aspect of the present invention, radiation that measures the temperature of a temperature measurement object, which is a melt that transmits at least part of heat radiation light, is not specified in advance. An imaging unit for imaging the distribution of thermal radiance of the thermal radiation emitted from the temperature measurement object, and a maximum luminance detection unit for detecting the maximum luminance in the captured image captured by the imaging unit And a temperature calculation unit that calculates the temperature of the temperature measurement object based on the maximum luminance detected by the maximum luminance detection unit, the temperature calculation unit of the temperature measurement object with respect to the thermal radiation light When the reflection loss at the interface with the atmosphere is ln, the temperature of the temperature measurement object is calculated using any value of (1-ln) to 1 as the emissivity of the temperature measurement object at the highest luminance. A radiation temperature measuring device is provided.

  According to this configuration, the imaging unit can image the distribution of the thermal radiance of the thermal radiation emitted from the temperature measurement object of the melt whose emissivity is not specified in advance. That is, the captured image captured by the imaging unit includes a luminance distribution. Note that this luminance distribution may be represented as, for example, a distribution in a captured image having a density (also referred to as intensity) corresponding to the luminance of each pixel in accordance with the imaging element included in the imaging unit. Then, the maximum luminance detection unit can detect the maximum luminance included in the captured image. Then, the temperature calculation unit can calculate the temperature to be measured based on the maximum luminance. At this time, the temperature calculation unit can calculate the temperature of the temperature measurement target that transmits at least a part of the thermal radiation emitted by itself by setting the emissivity to (1-ln) to 1. . That is, the temperature calculation unit uses the relationship between the thermal radiance of a high-temperature object such as Planck's radiation equation or Wien's equation and a black body, and sets the emissivity of the temperature measurement object to (1−ln) −1. It is possible to calculate the temperature of the temperature measurement target with any value and with the thermal radiance of the temperature measurement target as the maximum brightness in the captured image.

In addition, when the temperature measurement object is a molten slag included in the tidal stream discharged from the blast furnace, the temperature calculation unit may be any one of 0.96 to 1 as the emissivity of the temperature measurement object at the highest luminance. Such temperature may be used to calculate the temperature of the molten slag.
According to this configuration, the temperature of the molten slag whose emissivity cannot be measured can be calculated by setting the emissivity to 0.96 to 1. That is, at this time, the temperature calculation unit uses the relationship between the thermal radiance of a high-temperature object and a black body, such as Planck's radiation equation and Wien's equation, for example, and sets the emissivity of the temperature measurement object to 0.96-1 And the temperature of the molten slag can be calculated with the thermal radiance of the molten slag as the highest luminance in the captured image.

In addition, when the surface of the temperature measurement object is in a wavy state, the temperature calculation unit may use a value corresponding to the magnitude of the wave as the emissivity.
Here, the temperature of the temperature measurement object whose surface is rippled, that is, the temperature measurement object whose surface is uneven is measured. In the part located in the wave valley (concave), the light emitted by the thermal radiation of the temperature measurement object is reflected by the direct light reflected by the temperature measurement object in addition to the direct light emitted from the surface of the temperature measurement object. Including light. Therefore, the maximum luminance detection unit can detect the luminance of light including direct light and reflected light as the maximum luminance, and the temperature calculation unit calculates the temperature of the temperature measurement object based on the maximum luminance. Can do. At this time, whether or not the reflected light is included or the order of the reflected light is different depending on the magnitude of the wave, but according to the above configuration, a value corresponding to the magnitude of the wave is used as the emissivity. . Therefore, more accurate temperature measurement is possible. It should be noted that the size of the wave used when determining the emissivity is desirably set as appropriate so that direct light reflection can occur.

Further, the temperature calculation unit calculates the temperature of the temperature measurement object by using 1 as the emissivity of the temperature measurement object at the highest luminance when the surface of the temperature measurement object is in a wavy state. May be.
Here, the temperature of the temperature measurement object whose surface is rippled, that is, the temperature measurement object whose surface is uneven is measured. According to this configuration, the temperature calculation unit can calculate the temperature of the temperature measurement object by setting the emissivity of the temperature measurement object to 1 at the maximum luminance. In other words, the temperature calculation unit uses the relationship between the thermal radiance of a high-temperature object and a black body, such as Planck's radiation equation and Wien's equation, and the emissivity of the temperature measurement object is 1, and the temperature measurement object The temperature of the temperature measurement target can be calculated with the thermal radiance of the temperature as the highest luminance in the captured image. As described above, when waves are generated on the surface, the distribution of thermal radiance captured by the imaging unit includes not only direct light but also reflected light. Therefore, the emissivity for the highest luminance of the melt that is waved in this way approaches 1. If the melt transmits at least part of the thermal radiance, the apparent emissivity (effective emissivity) approaches 1 as the thickness of the melt increases. Therefore, according to this configuration, by approximating the emissivity to 1, it is possible to measure the temperature of the temperature measurement object whose emissivity is unknown.

The maximum luminance detection unit may detect the maximum luminance over a plurality of captured images captured by the imaging unit.
According to this configuration, the maximum luminance detection unit detects the maximum luminance from a plurality of captured images. As described above, the maximum brightness detection unit detects the maximum brightness in the captured image. However, since the temperature measurement target is a melt, the thickness and surface state of the temperature measurement target change, and the maximum brightness according to the change. Also changes. Therefore, with the above configuration, it is possible to increase the probability of detecting the highest maximum luminance independent of the thickness and surface state by imaging a plurality of temperature measurement objects and detecting the maximum luminance over the plurality of captured images. I have to. For example, when the emissivity of the maximum luminance depends on the thickness of the temperature measurement target, the probability that the maximum luminance at which the thickness of the temperature measurement target is maximum can be detected can be increased. Furthermore, for example, the probability that reflected light depending on the surface state (wave shape) of the temperature measurement target is included in the captured image can be increased. Therefore, the temperature measurement accuracy of the radiation temperature measuring device can be improved.

The imaging unit may include a high-speed shutter that exposes the imaging device for a predetermined time according to the flow state of the temperature measurement target.
According to this configuration, the high-speed shutter can set the time for exposing the image sensor to a predetermined time according to the flow state of the temperature measurement object (the undulation or the change in the thickness of the temperature measurement object). Therefore, the imaging unit prevents the flowing temperature measurement object from being imaged and blurred and taking the luminance of light including direct light and reflected light to prevent the maximum luminance from being averaged with other luminance. Can be included.

In order to solve the above problem, according to another aspect of the present invention, the emissivity is not specified in advance, and the temperature of the temperature measurement object that is a melt that transmits at least part of the heat radiation light is set. A radiation temperature measurement method for measuring, an imaging step for imaging the thermal radiance distribution of the temperature measurement object, a maximum luminance detection step for detecting the maximum luminance in the captured image captured in the imaging step, and A temperature calculating step for calculating a temperature of the temperature measurement object based on the highest luminance detected in the maximum luminance detection step, and in the temperature calculation step, the temperature measurement object air with respect to the heat radiation light and When the reflection loss at the interface of ln is assumed to be ln, the temperature of the temperature measurement object is calculated using any value of (1-ln) to 1 as the emissivity of the temperature measurement object at the highest luminance. Features Ihaka temperature method is provided.
According to this configuration, the temperature of the temperature measurement target can be calculated.

  Further, in the temperature calculation step, when the temperature measurement object is a molten slag included in the tidal stream discharged from the blast furnace, the emissivity of the temperature measurement object at any one of 0.96 to 1 at the highest luminance is selected. Such temperature may be used to calculate the temperature of the molten slag.

  In the temperature calculation step, when the surface of the temperature measurement object is in a wavy state, a value corresponding to the magnitude of the wave may be used as the emissivity.

  In the temperature calculation step, when the surface of the temperature measurement object is in a wavy state, the temperature measurement object temperature is calculated using 1 as the emissivity of the temperature measurement object at the highest luminance. May be.

  In the highest luminance detection step, the highest luminance over a plurality of captured images taken by the imaging unit may be detected.

  In the imaging step, the imaging element may be exposed for a predetermined time according to the flow state of the temperature measurement object with a high-speed shutter.

  As described above, according to the present invention, for example, the temperature of a temperature measurement object, which is a melt whose accurate emissivity is not specified in advance, such as molten slag contained in the outflow from a blast furnace, Temperature can be measured by contact.

It is explanatory drawing for demonstrating the structure of the radiation temperature measuring apparatus which concerns on one Embodiment of this invention. It is explanatory drawing for demonstrating the apparent emissivity of a molten slag. It is explanatory drawing for demonstrating the apparent emissivity of a molten slag. It is explanatory drawing for demonstrating the relationship between the thickness of molten slag, and an effective emissivity. It is explanatory drawing for demonstrating the apparent emissivity of a molten slag. It is explanatory drawing for demonstrating the relationship between the flat surface emissivity of a molten slag, and an apparent emissivity. It is explanatory drawing for demonstrating the relationship between the flat surface emissivity of a molten slag, and an apparent emissivity. It is explanatory drawing for demonstrating the temperature calibration by the radiation thermometer which concerns on one Embodiment of this invention. It is explanatory drawing for demonstrating operation | movement of the radiation temperature measuring device which concerns on the same embodiment. It is explanatory drawing for demonstrating the example of a measurement by the radiation temperature measuring device which concerns on the same embodiment. It is explanatory drawing for demonstrating the tidal flow discharged from a blast furnace. It is explanatory drawing for demonstrating the thermal radiance histogram by the tidal current output from a blast furnace.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

  The radiation temperature measuring device according to the embodiment of the present invention can measure a temperature measurement object that is various melts, but in particular, the accurate emissivity is unknown or the accurate emissivity measurement is possible. In a difficult case, it is possible to measure a temperature measurement object of a melt whose emissivity is not specified in advance and which transmits at least part of the thermal radiation emitted by itself. As an example of the case where the emissivity is not specified in advance, for example, when the surface of the temperature measurement object is melted and a wave is generated on the surface, the emissivity is equal to the thickness of the temperature measurement object. Depending on the case, the thickness is not specified in advance, the temperature measurement target is a mixture and the mixing ratio is not specified in advance, the temperature measurement target component is not specified in advance, and the like. The radiation temperature measuring device according to an embodiment of the present invention can accurately measure the temperature of a temperature measurement object whose emissivity is unknown. Needless to say, this radiation temperature measuring device can also measure a temperature measurement object whose emissivity is known or a temperature measurement object that is not a melt.

  Below, for convenience of explanation, as such a temperature measurement object, “molten slag” included in the tidal stream discharged from the outlet of the blast furnace in the ironworks will be described as an example. In the case of this example, not only molten slag but also molten iron is output from the outlet. The radiation temperature measuring device according to the embodiment of the present invention can measure not only one temperature measuring object but also a temperature measuring object in a state where a plurality of melts such as hot metal and molten slag are mixed. . Before describing the radiation temperature measuring device in order to more clearly describe these effects that the radiation temperature measuring device according to the embodiment of the present invention can exhibit, the temperature in the blast furnace exemplified below is described. An outline of the measurement will be described with reference to FIGS. However, as described above, the radiation temperature measuring device according to the embodiment of the present invention can measure not only the molten slag exemplified below but also various temperatures to be measured.

<1. Temperature measurement in blast furnace>
FIG. 1 is an explanatory diagram for explaining a configuration of a radiation temperature measuring device according to an embodiment of the present invention. FIG. 11 is an explanatory diagram for explaining a tapping flow discharged from the blast furnace. FIG. 12 is an explanatory diagram for explaining a thermal radiance histogram due to the tidal flow output from the blast furnace.

(1-1. Overview of blast furnace operation)
Ironworks blast furnaces produce hot metal and molten slag from iron ore, coke, limestone, etc. using a high-temperature reduction reaction. Hot metal and molten slag are dripped at the bottom of the blast furnace to form a hot water pool. As shown in FIG. 1, a pouring hole 10 is provided at the position of the hot water pool on the side surface of the blast furnace. "It is also called" Outflow 1 ") flows out. The spout 10 is filled with mud material, and the through hole 11 is mechanically opened with a drill or the like. The diameter of the tap hole immediately after opening of the through hole 11 (the diameter of the through hole 11) is substantially equal to the diameter of the drill, but erodes with the progress of the tap hole and gradually expands. At the start of brewing, the brewing flow rate is less than the amount of hot metal and molten slag produced in the furnace, and the amount of hot metal and molten slag in the furnace increases. If you continue the output, the output diameter will increase. As the tap diameter increases, the tap flow increases, and the amount of hot water in the furnace starts to decrease. Normally, since the level of the hot water drops to the vicinity of the tap opening in about 2 to 4 hours from the start of the tapping, the mud material is filled in the through hole 11 of the tapping opening 10 to block the tapping opening 10. Pig iron is manufactured while repeating such a tapping operation. The hot metal and molten slag that have been fed out are transported through the feed 12 and are separated by specific gravity at the tail of the feed 12.

  The temperature of the outlet flow taken out from the outlet 10 (hereinafter also referred to as “the output temperature”) is important information for knowing the thermal state of the lower part of the furnace where the inside cannot be observed directly. If the tapping temperature decreases, the activity of the reduction reaction in the furnace may be deteriorated. It is necessary to pay attention also to the temperature of the tapping temperature, and there is a suspicion that some unsteady state has occurred in the furnace due to the rapid temperature change. Therefore, in order to properly operate the blast furnace, it is necessary to measure the tapping temperature and quickly and accurately determine the condition of the blast furnace and take an operation action. Thus, the output temperature is operation information that should always be carefully monitored. In addition, since hot metal and molten slag flow out from the same location of the hot water pool in the furnace, it is expected that there is no temperature difference between them.

(1-2. Method for measuring output temperature according to related technology)
Next, a method for measuring the tapping temperature according to the related art performed in such a blast furnace will be described. In the management of the temperature of the hot metal according to the related art, the temperature of the hot metal is generally measured with a thermocouple downstream of the hot metal 12. This temperature measurement method is a batch measurement method in which a disposable thermocouple probe called “immersion-consumable thermocouple” is manually immersed in hot metal. Contact-type temperature measuring devices using thermocouples can measure temperature with high accuracy and reliability. However, since the thermocouple probe is immersed manually, it is necessary for the worker to approach the output stream 1 and the thermocouple probe dissolves due to the high temperature of the output stream 1, and in most cases cannot be reused. is there. Therefore, temperature measurement by related techniques is limited to intermittent measurement several times during output due to restrictions such as the load received by the operator and the cost of the noble metal thermocouple probe. Further, since the heat is removed by the refractory constituting the output 12 for a while after the start of the start, the hot metal temperature measured downstream of the output 12 is the time when the output is output from the output 10. There is a possibility that it is lower than the temperature (the temperature that you really want to know when you know the situation inside the furnace).

  The inventors of the present invention have conducted extensive research on a temperature measuring device for a high-temperature melt. As a result, when a two-dimensional distribution of the thermal radiance of thermal radiation emitted from the outflow is imaged with a high-speed shutter, It was discovered that the molten slag can be observed separately (see FIG. 11C, etc.). Therefore, the inventors of the present invention have devised the radiation temperature measuring device disclosed in Patent Document 1 as a result of intensive studies on the phenomenon that the molten iron and molten slag are separated and extracted. . This radiation temperature measuring device analyzes the density (image brightness) output by the image sensor in accordance with the radiance in the picked-up thermal radiance image, and calculates a density histogram. Here, the radiation temperature measuring device can detect the image luminance Lm (density at which the number of pixels is maximized) of the distribution peak P1 of the hot metal image on the density histogram (see FIG. 12). As a result, the radiation temperature measuring device can calculate the temperature from the image luminance Lm of the molten iron image distribution peak P1. The radiation temperature measuring device according to the related art invented by the inventors of the present invention can measure a change in the hot metal temperature in a short time that cannot be captured by the contact temperature measuring device, and the like, and A contact-type temperature measuring device or the like is very useful because it can measure the temperature in the vicinity of a spout where an operator cannot approach.

(1-3. Improvement points of the radiation temperature measuring device according to related technology)
However, in managing the operating state of the blast furnace, it has been desired not only to measure the hot metal temperature but also to measure the temperature of the molten slag flowing out of the blast furnace in the same manner as the hot metal. On the other hand, the radiation temperature measuring device described in Patent Document 1 according to the related art cannot measure the temperature of the molten slag. Thus, there has been a demand for the development of a radiation temperature measuring device that can further measure the temperature of the molten slag.

  The case where the temperature measurement of the molten slag is desired and the case where the temperature of the molten slag cannot be measured by the radiation temperature measuring device according to the related art will be described in detail as follows.

  During the brewing from the blast furnace, it takes a long time for the molten iron and molten slag to flow out of the brewing port 10 at the same time, but the initial brewing (predetermined period after starting the brewing) During a predetermined period before being blocked with a mud material or the like, only molten slag may flow out of the spout 10. In FIG. 11, an example of the change of the mixing state of the molten slag and hot metal during a tapping is shown. In addition, FIG. 11 shows a state where the tapper 10 is on the left side of the page, and the tapper flows out to the right. FIGS. 11A to 11C show captured images of the radiance of the tidal current immediately after the tapping, the hot metal outflow start period, and the stable tapping period, respectively. A part (bright part) with high (image brightness) is molten slag, and a part (dark part) with low density is hot metal.

  For example, in the case of the example shown in FIG. 11, only the molten slag (bright part) flows out as shown in FIG. The subsequent few minutes are a transition period in which the outflow amount of the molten iron (dark part) gradually increases as shown in FIG. When the time further elapses, the molten iron ratio with respect to the molten slag is stabilized in a high state as shown in FIG. This stable brewing period usually lasts about 2 hours or more, during which time molten iron is produced. The radiation temperature measuring device according to the related technique obtains the hot metal temperature by paying attention to the hot metal region (dark region) on the thermal image. Therefore, this radiation temperature measuring device measures the temperature of the hot metal in the hot metal outflow start period (FIG. 11 (b)) and the stable hot metal output period (FIG. 11 (c)) in which the hot metal is included in the hot metal flow, You can know the operating condition in the furnace. However, the operation state in the furnace cannot be known through the temperature of the hot metal during a period in which only the molten slag of about 30 minutes flows out after the start of pouring.

  On the other hand, in order to manage the operating state of the blast furnace more effectively and appropriately, it is necessary to obtain more information about the heat state in the blast furnace. And the temperature inside the blast furnace immediately after the start of tapping is also noteworthy information. Since it is empirically known that the molten iron slag is composed of 100% molten iron and does not contain molten slag, if the molten slag temperature can be measured, the temperature of the blast furnace during extraction can be calculated. It becomes possible to measure continuously including the initial stage. Accordingly, there has been a demand for the development of a radiation temperature measuring device that can measure the temperature of the molten slag.

  On the other hand, as described above, the radiation temperature measuring device according to the related art can extract the concentration (image luminance) in the captured image representing the radiance of the thermal radiation light of the hot metal, and from this concentration, the temperature of the hot metal Is calculated. In order to calculate the temperature from the radiance, it is necessary to determine the emissivity of the temperature measurement object, but the emissivity of the hot metal can be measured and is generally known (about 0.4). However, when the temperature of the molten slag is measured by the radiation temperature measuring device according to this related technique, the emissivity becomes a problem.

The component of slag discharged from the blast furnace is, for example, CaO, SiO ₂ , Al ₂ O, and the like, and varies depending on the raw material used, the reaction state in the furnace, and the like. These mixing ratios also vary depending on the reaction state in the furnace. As a result, the emissivity of the molten slag is considered to change due to fluctuations in the slag components and fluctuations in their mixing ratio. On the other hand, the density (corresponding to the observed radiance, also referred to as image brightness) on the thermal image is expressed as a function of the temperature to be measured and the emissivity, so that the emissivity is not constant in this way. The image density of slag varies greatly. Moreover, it is considered that the variation in the image density of the molten slag is increased because the molten slag flows and the surface state always changes. For example, when the histogram of the outflow portion of FIG. 11C is obtained, the peak P2 of the molten slag is unclear as shown in FIG. If the concentration peak P2 of the molten slag has a width of about 10 levels in concentration, this width corresponds to a temperature uncertainty of about 20 ° C. or higher. Therefore, it is difficult to measure temperature using a method that focuses on the luminance of the molten slag.

  Further, a temperature measurement error due to emissivity instability in radiation temperature measurement can be estimated from a theoretical formula of black body radiation. For example, when radiation temperature measurement is performed by observing an object at 1500 ° C. at a wavelength of 0.65 μm, the emissivity is assumed to be 0.7, and when the emissivity changes by ± 0.1, the temperature is ± 20. It causes a measurement error of ° C. This error is not an acceptable measurement error.

In other words, when performing radiation temperature measurement of molten slag,
(1) It is difficult to specify a representative value of concentration corresponding to the luminance of molten slag,
(2) It is difficult to calculate the temperature by setting the emissivity of the molten slag as accurate as acceptable.
The radiation temperature measuring device according to the related technology has been difficult to measure the temperature with sufficient accuracy.

The temperature measurement in the blast furnace has been described above.
The inventors of the present invention, as a result of earnest research on the temperature measurement performed in the blast furnace and the problems of the temperature measuring device according to the related technology, as a result of elucidating the above problems, In addition, the radiation temperature measuring device according to one embodiment of the present invention capable of measuring not only a temperature measurement object that is not only molten slag but also other melts has been invented. Hereinafter, a radiation temperature measuring device according to an embodiment of the present invention will be described.

<2. One Embodiment>
(2-1. Outline: Emissivity of molten slag)
When the inventors of the present invention invented the radiation temperature measuring device according to one embodiment of the present invention, the maximum image luminance Lmax (an example of a temperature measurement object) in a molten slag whose emissivity is not specified in advance ( It was found that the temperature of the molten slag can be measured by using the highest concentration. At this time, the inventors of the present invention have further found that the apparent emissivity of the molten slag at the maximum image luminance Lmax can be assumed to be a specific value. As the value, 0.96 to We have found that any value of 1 (particularly preferably 1) can be used. The “apparent emissivity (also referred to as effective emissivity)” as used herein refers to an effective emissivity that varies depending on the state and shape of the observation target, not the emissivity determined by the substance.

  And based on the consideration with respect to the emissivity of this molten slag, the inventors of the present invention, in the case of another temperature measurement object, the relationship between the temperature measurement target atmosphere and the thermal radiation emitted from the temperature measurement object. When the reflection loss at the interface (hereinafter also referred to as “interface radiation loss”) is ln, any value from (1−ln) to 1 can be used as the apparent emissivity of the temperature measurement object at the maximum luminance. I also found out. The temperature measurement object that is not the molten slag will be described in detail later. In the following, in order to facilitate the understanding of the present invention, before describing the specific configuration of an embodiment of the present invention, the inventors mainly clarified the results of intensive research. The apparent emissivity of the molten slag will be described.

If the wavelength λ ([m]) is a wavelength region from visible light to near-infrared light as heat radiation light emitted from a temperature measurement object, not limited to molten slag, heat of heat radiation light emitted from the temperature measurement object a radiance _{I h,} the relationship between the object being measured temperature T ([K]), the formula of Wien, known as an approximate expression of the blackbody radiation formula Planck. That is, the relationship between the thermal radiance I _h, and the temperature-measured object temperature T ([K]) is represented by Formula 1 below.

Here, ε is the emissivity of the temperature measurement object, c ₁ is the first constant of black body radiation (1.1910 × 10 ⁻¹⁶ [Wm ⁻² ]), and c ₂ is the second constant of black body radiation (0. 014388 [mK]) and λ each represent an observation wavelength ([m]). Since the wavelength λ is fixed by the photodetector, the temperature T and the emissivity ε are variables on the right side of Equation 1. A low even emissivity ε be the same temperature T hot radiance I _h is small. In the radiation temperature measurement, this thermal radiance _Ih is observed. In radiation temperature measurement using an imaging device, an image luminance (concentration) L is obtained as an observation amount (output signal), which corresponds to thermal radiance (usually, thermal radiance I and image luminance L are Proportional relationship). Therefore, even if the measurement target temperature T is the same, if the emissivity ε is low, the image luminance L is also low. Note usually determined in advance experimentally the relationship between the (apparent temperature of assuming an object and blackbody) T _b image luminance L and blackbody temperature. This relationship is, for example, as shown in FIG. If the measurement object is not a black body (i.e. emissivity epsilon <1) case, the true temperature T becomes higher than the black body temperature T _b, the relationship between them is described by the following equation 2. Any true temperature T and blackbody temperature T _b in formula 2 given in absolute temperature.

  Next, the thermal image of the tidal stream is considered. 1 is imaged, and the density (image luminance) included in the captured image illustrated in FIG. 11C is analyzed. As shown in the density histogram shown in FIG. It can be seen that the concentration peak P1 corresponding to the radiance and the concentration peak P2 corresponding to the radiance of the molten slag have a certain degree of dispersion. It can also be seen that the dispersion of the molten slag concentration peak P2 is larger than the dispersion of the molten iron concentration peak. Focusing on the concentration peak P2 of the molten slag having a large dispersion, in the example shown in FIG. 12, the maximum image luminance Lmax (maximum concentration) is about 175, which is from the center of the concentration peak P2 of the molten slag. The gap is large.

  Moreover, since molten slag and hot metal flow out from the same location of the hot water pool in the furnace, it can be approximated that there is no temperature difference between them, and can be approximated without any temperature difference in the entire molten slag. On the other hand, as shown in FIG. 12, in the molten slag, the deviation from the center of the density peak P2 at the maximum image luminance Lmax is large (this deviation is referred to as “density difference ΔL”). In Equation 1, due to the fact that the temperature T is constant and the concentration difference ΔL is large, there is a portion where the apparent emissivity is locally high in the molten slag in the outgoing stream 1. become.

As a result of intensive studies on the reason why the apparent emissivity is locally increased in this way, the inventors of the present invention have clarified the following two characteristics of molten slag as a result of the research. Succeeded.
Characteristic 1: The molten slag is optically translucent Characteristic 2: Reflected light is included in the thermal image of the molten slag The characteristics 1 and 2 will be specifically described as follows. In the following, the intensity of thermal radiation light is represented by thermal radiance I, which is a physical quantity, and image luminance (density) L, which is an observation quantity corresponding to this, is described as necessary.

(2-1-1. Property 1: Molten slag is optically translucent)
The characteristic 1 that the inventors of the present invention have clarified that the apparent emissivity of the molten slag is locally increased will be described with reference to FIGS. In this description, it is assumed that the characteristic 1 is handled alone and the characteristic 2 is not included. 2 and 3 are explanatory diagrams for explaining the apparent emissivity of the molten slag. FIG. 4 is an explanatory diagram for explaining the relationship between the thickness of the molten slag and the apparent emissivity.

  The inventors of the present invention investigated the reason why the dispersion of the concentration peak P2 of the molten slag in the blast furnace discharge flow is larger than that of the hot metal, and as a result, the apparent emissivity is locally increased. . As a result of collecting and analyzing the molten slag contained in the output stream 1, the inventors of the present invention have optically translucent the molten slag at the wavelength observed by the imaging device if the thickness of the molten slag is about several millimeters. I found out.

  Based on the fact that the molten slag is optically translucent, that is, transmits at least part of the heat radiation light, the inventors of the present invention set the apparent emissivity of the molten slag as follows: Consider.

  As shown in FIG. 2, the molten iron flow 1 discharged from the discharge port 10 includes molten iron Me and molten slag Sl. As shown in FIG. 11C and the like, the molten slag Sl is separated and mixed in the molten iron Me in the stable brewing period. FIG. 2 schematically shows a state where the molten slag S1 is mixed and the radiance emitted therefrom.

  The radiance I1 represents the brightness of the radiated light emitted from the surface of the hot metal Me. The emissivity of the radiance I1 is constant at the emissivity of the hot metal Me (about 0.4). That is, the radiance I1 is a function of temperature only. On the other hand, the radiances I2 and I3 represent the radiance of the radiated light emitted from the surface of the molten slag Sl. The emissivity of the radiances I2 and I3 depends not only on the temperature but also on the thickness of the molten slag Sl according to the translucency of the molten slag S1 found by the inventors of the present invention. Accordingly, the luminance of the radiance I3 is higher than that of the radiance I2. The radiance I3 is considered that the thickness of the molten slag S1 is sufficiently thick, and the emissivity is stable at a value unique to the molten slag S1. In contrast, the radiance I2 is considered to be in a state in which the radiance emitted from the molten iron Me is added because the thickness of the molten slag S1 is not sufficient and the molten slag S1 is translucent. .

  FIG. 3 shows a radiance I2 in which a part of the radiated light from the molten iron Me is transmitted through the molten slag Sl and the radiated light of the molten slag Sl itself is added, and the surfaces of the molten iron Me and the molten slag Sl are flat. Assuming that there is, it is shown schematically in detail. In FIG. 3, the radiance Is represents the brightness of the radiated light emitted from the molten slag Sl itself, and the radiance Im represents the brightness of the radiated light emitted from the molten iron Me and transmitted through the molten slag Sl. On the other hand, the radiance I in FIG. 3 represents the luminance imaged by the imaging unit 110. That is, the radiance I represents the radiance I2 (in some cases, radiance I3) in FIG. 2 emitted from the surface of the molten slag Sl. The imaging unit 110 used in one embodiment of the present invention will be described in detail later.

  When the thickness of the molten slag Sl is d, the radiances Is and Im are both expressed as a function of d. Accordingly, the imaged radiance I (that is, the apparent radiance) is also a function of the thickness d of the molten slag Sl. Needless to say, the radiances I, Is, and Im are also functions of the temperature T.

  Here, if it is assumed that rays of radiance Is and Im pass vertically through the interface between the molten slag Sl and the atmosphere (medium), the loss of radiance generated at the interface, that is, the interface reflection loss ln is From the geometric optics theory, it is expressed by the following formula 3.

In Equation 3, n ₀ represents the refractive index (1.0) of the atmosphere, and n represents the refractive index of the molten slag Sl. When the molten slag Sl contained in the molten iron stream 1 and separated from the molten iron Me was collected and its refractive index n was measured, the inventors of the present invention confirmed that the refractive index n was about 1.5. did.

  Like the emissivity of the molten slag Sl, this refractive index n is also expected to change slightly depending on the components and mixing ratio contained in the molten slag Sl. For convenience of explanation, the refractive index n is assumed to be 1.5 here. Assume. Then, from the above equation 1, it can be seen that the interface reflection loss ln of the molten slag S1 is about 4% (ln≈0.04).

On the other hand, when the apparent radiance I to be imaged is considered, it is expressed by the following equations 4 and 5. In Equations 4 and 5, d represents the thickness ([mm]) of the molten slag Sl as described above, ε _s (d) represents the emissivity of the molten slag Sl according to the thickness d, and τ _s ( d) represents the transmittance of the molten slag Sl according to the thickness d, and ε _m represents the emissivity of the hot metal Me. I _b is the black body radiance ([W · m ⁻² · μm ⁻¹ · sr ⁻¹ ]) of the Wien equation, and is expressed by the following equation (6). As described above, in Equation 6, c ₁ is the first constant of black body radiation (1.1910 × 10 ⁻¹⁶ [Wm ⁻² ]), and c ₂ is the second constant of black body radiation (0.014388 [ mK]) and λ each represent an observation wavelength ([m]).

  Strictly speaking, the radiance I shown in Equation 4 includes multiple reflections inside the molten slag Sl. However, since the interface reflection loss ln calculated from the above equation 3 is 4% and there is attenuation during propagation in the molten slag S1, the component of such internal multiple reflection is so small that it can be ignored.

Further, the transmittance τ _s of the molten slag Sl in the above formula 5 is expressed by the following formula 7 based on Lambert Beer's law and the interface reflection loss ln between the slag and the atmosphere. Similarly, the emissivity ε _s of the molten slag _S1 is expressed by the following formula 8. Note that k in Equation 7 is the attenuation coefficient ([1 / mm]) of the molten slag Sl.

  Therefore, by substituting Formula 7 and Formula 8 into Formula 5 above, the apparent radiance I of the molten slag S1 is expressed by Formula 9 below. The imaging unit 110 according to an embodiment of the present invention observes this radiance I. In Equation 9, the apparent emissivity ε of the radiance I emitted from the surface of the molten slag Sl, that is, the apparent emissivity ε (d) is expressed by Equation 10 below.

  The inventors of the present invention experimentally obtained the attenuation coefficient k by using a sample of the molten slag Sl from which the interface reflection loss ln was obtained. That is, the thickness d is measured on the sample of the molten slag Sl, and the sample is irradiated with a light beam (semiconductor laser) having the same wavelength λ as the wavelength λ imaged by the imaging unit 110 used in the embodiment of the present invention. The transmitted light intensity was observed. As a result, 0.37 [1 / mm] was obtained as the attenuation coefficient k of the molten slag Sl.

Substituting the above k = 0.37 [1 / mm] into Equation 10 yields a graph representing the change in apparent emissivity ε using the thickness d of the molten slag Sl as a parameter (see FIG. 4). The apparent emissivity ε increases according to the thickness d from the emissivity ε _m (≈0.4) of the molten iron Me, and finally converges to about 0.96. The focused value of the effective emissivity ε can be found from the value obtained by substituting the interface reflection loss ln into the following equation 11 when the thickness d in the equation 10 is infinite.

  As can be seen from the above equation 10 and FIG. 4, the apparent emissivity ε can be regarded as highly stable from the vicinity where the thickness d of the molten slag Sl reaches 10 mm. On the other hand, the diameter of the outgoing stream 1 is about 100 mm, and in the actual thermal image as shown in FIGS. 11B and 11C, the size of the molten slag Sl on the surface is about 10 mm. Therefore, it is considered that the thickness (depth) d of the molten slag S1 is about 10 mm at such a portion.

  In other words, based on such findings (characteristic 1 and the like) and considerations, the inventors of the present invention can obtain the highest image luminance Lmax as a result of imaging the highest thermal radiance in the thermal radiation of the molten slag Sl. It has been found that the apparent emissivity ε corresponding to can be considered to be about 0.96. In addition, from the above viewpoint with respect to the apparent emissivity ε of the molten slag Sl, the inventors of the present invention can also measure a temperature measurement object other than the molten slag when the temperature measurement object is optically transparent or translucent. Has clarified that the apparent emissivity ε of the temperature measurement object also satisfies the above-mentioned formula 11.

(2-1-2. Characteristic 2: Reflected light is included in thermal image of molten slag)
Next, the characteristic 2 which the inventors of the present invention have clarified that the apparent emissivity of the molten slag is locally increased will be described with reference to FIGS. Here, in order to make the explanation easy to understand, the apparent emissivity described in the above description of the characteristic 1 is “the emissivity is a function of the thickness of the molten slag when the surface of the molten slag is flat”. It is called “surface emissivity” and is simply written as ε. Then, the fact that the flat surface emissivity changes depending on the surface shape of the molten slag is treated as “apparent emissivity” (symbol E). FIG. 5 is an explanatory diagram for explaining the apparent emissivity of the molten slag. FIG.6 and FIG.7 is explanatory drawing for demonstrating the relationship between the flat surface emissivity of molten slag, and an apparent emissivity.

  The inventors of the present invention have found that the dispersion of the concentration peak P2 of the molten slag in the blast furnace discharge flow is larger than that of the hot metal, and as a result, the apparent emissivity is locally increased as described above in the characteristic 1 We investigated whether there was any other cause. As a result, the inventors of the present invention have found that the thermal image of the molten slag contains reflected light. That is, the inventors of the present invention consider the emissivity of molten slag as follows.

  The outgoing stream 1 discharged from the blast furnace is a molten material and is flowing, and waves are generated on its surface. In particular, the molten slag has a high viscosity, and the surface state of the molten slag in the output stream 1 has a non-flat shape in which waves, irregularities, bumps, and the like are generated. FIG. 5 shows the state of the surface S of the molten slag S1. The surface S of the molten slag S1 emits thermal radiation having thermal radiance (direct light I0) corresponding to the temperature T and the emissivity ε (flat surface emissivity). Considering the thermal radiation imaged by the imaging unit 110 according to an embodiment of the present invention, not only the direct light I0 from the surface S of the molten slag S1 but also the direct light I0 emitted from another location is the molten slag. The reflected light Iri reflected from the surface S (i is a natural number representing the number of reflections) is also simultaneously imaged by the imaging unit 110. Therefore, the apparent emitted light I imaged by the imaging unit 110 is expressed by the approximate expression 12.

  According to Kirchhoff's law in optics, the emissivity ε is equal to the light absorption rate a, and the light reflectance r is expressed as r = 1−a = 1−ε. Accordingly, the density Iri of each reflected light Lri on the molten slag is expressed by the equations 13 and 14 by the number of reflections i and the reflectance r.

In this equation 13, _Ib represents black body radiance. From Expression 13, Expression 12 is expressed as Expression 15 and Expression 16 below.

  Therefore, the apparent emissivity E of the radiance I imaged on the image sensor of the imaging unit 110 is expressed by the following equation 17 by the flat surface emissivity ε of the molten slag.

  The relationship between the flat surface emissivity ε and the apparent emissivity E including the reflected light calculated from these equations is shown in FIGS. 6 and 7, when the reflected light is not included (flat surface emissivity ε), when the primary reflected light (i = 1) is included, the secondary reflected light (i = 1, 2) is included. In this case, the apparent emissivity E in the case where even the third-order reflected light (i = 1, 2, 3) is included is shown. FIG. 7 is an enlarged view of FIG. 6 in the range where the flat surface emissivity ε and the apparent emissivity E are 0.9 to 1.

  As shown in FIGS. 6 and 7, it can be seen that the apparent emissivity E is closer to 1 than the flat surface emissivity ε if the reflected light overlaps. As the molten slag is thicker and the flat surface emissivity ε is closer to 1, the apparent emissivity E is also closer to 1, but even if the flat surface emissivity ε is not close to 1, it contains reflected light as described above, As the number of reflections increases, the apparent emissivity E approaches one. Since a melt such as molten slag is flowing, there is a wave in the surface state, and apparent radiant light may include high-order multiple reflected light.

  For example, when the molten slag is thick and the molten slag has a flat surface reflectance ε of 0.96 and further includes primary reflected light, the apparent emissivity E of light imaged by the imaging unit 110 is 0.998. If the apparent emissivity E is 0.998, even if the emissivity is assumed to be 1, the temperature measurement error is only 0.3 ° C., which is not a problem in practical use. Further, for example, when the reflected light of the second order or higher is included, the apparent emissivity is approximately 1.000, and the measurement error can be further reduced.

  That is, based on such findings (characteristics 2 and the like) and considerations, the inventors of the present invention have found that when the surface of the molten slag S1 is waved, the apparent emissivity E corresponding to the maximum luminance is half It has been found that the flat surface emissivity ε due to transparency is closer to 1 than the maximum value. In addition, from the above viewpoint with respect to the apparent emissivity E of the molten slag Sl, the inventors of the present invention can also measure a temperature measurement object other than the molten slag when the temperature measurement object is a melt and the surface is rippled. Clarified that the apparent emissivity E of the temperature measurement object is closer to 1 than the flat surface emissivity or the true emissivity.

(2-1-2. Summary of apparent emissivity)
As described above, the inventors of the present invention have made extensive studies on the fact that the apparent emissivity is locally increased in the molten slag in the outgoing stream 1, and the characteristics 1 and 2 of the molten slag have been clarified. And the apparent emissivity E of the molten slag, which was clarified for the first time based on the characteristics 1 and 2, was explained. Summarizing the apparent emissivity E, the following conditions 1 and 2 can be said.

Condition 1: The molten slag is optically translucent. In this case, the apparent emissivity ε of the molten slag at the maximum luminance (maximum image luminance Lmax) can be regarded as 0.96.
Condition 2: When the surface of the molten slag is rippled, the captured image contains single or multiple reflected light. Therefore, the apparent emissivity E of the molten slag at the highest luminance (maximum image luminance Lmax) It further approaches 1 from an emissivity of 1 (flat surface emissivity ε).

  Therefore, when measuring the molten slag, the radiation temperature measuring device according to the embodiment of the present invention uses any value of 0.96 to 1 as the emissivity E with respect to the maximum image luminance Lmax. The temperature T can be obtained more accurately. Hereinafter, the radiation temperature measuring device according to the embodiment of the present invention will be described in detail.

(2-2. Configuration of the radiation temperature measuring device 100)
In FIG. 1, the structure of the radiation temperature measuring device 100 which concerns on one Embodiment of this invention is shown.
As shown in FIG. 1, the radiation temperature measuring device 100 according to the present embodiment includes an imaging unit 110, an image processing unit 121, an image data storage unit 122, a maximum luminance detection unit 123, a temperature calculation unit 124, A calibration data storage unit 125, a display unit 131, and a temperature data storage unit 132 are included.

  The imaging unit 110 is a two-dimensional distribution (also referred to as “thermal radiance distribution”) of the thermal radiance of the thermal radiation emitted from the tap flow 1 until it is output from the tap 10 and hidden by the cover 13. An example of thermal radiance distribution) is imaged. The imaging unit 110 is an example of a flowing melt, and images the thermal radiance of the molten slag contained in the outflow. The imaging unit 110 does not need to be close to the output stream 1 and can perform remote imaging. In addition, the imaging unit 110 is preferably housed in an air cooling jacket in which cooling gas blows out in front of the imaging surface in consideration of scattering of the outgoing flow 1 and ambient temperature. The imaging unit 110 includes a wavelength selection filter, a high-speed shutter, and an imaging device (not shown) in order to image the thermal radiance distribution.

  The wavelength selection filter is an example of a wavelength selection unit, and selects the wavelength of light that is transmitted to the image sensor. As the wavelength selection filter, for example, a filter having a center transmission wavelength of 0.65 μm can be used. This wavelength selection filter is arranged on the upstream side of the image sensor on the optical path of the light emitted from the temperature measuring object. That is, by arranging the wavelength selection filter, the image sensor can capture only the luminance of the substantially constant wavelength λ. Therefore, the wavelength λ at the time of temperature calculation described later is determined by this wavelength selection filter. However, if an imaging device capable of imaging only a substantially constant wavelength λ is used, the wavelength selection filter can be omitted.

  The high-speed shutter adjusts the exposure time so that the image sensor is exposed for a predetermined time. The high-speed shutter is, for example, an electronic shutter that electronically controls the exposure time of the image sensor. The output stream containing the molten slag is output at an ejection speed of, for example, 5 to 10 m / sec. Therefore, the exposure time by the high-speed shutter is set to a time according to the flow state of the molten slag, that is, a time at which this outflow does not “image flow”. In other words, as shown in FIGS. 11 (a) to 11 (c), the exposure time prevents the outflow from being imaged and blurred, and a marble pattern due to hot metal and molten slag. It is set to a time when imaging can be performed. Since the molten slag flows out in a turbulent state, it not only moves in the direction of jetting but also convects inside the outflow, and the state of the surface of the molten slag (waves and irregularities) It has changed. Here, for example, the state of molten slag (temperature measurement object that is a melt) in which the surface is waved and the surface state can change, such as a moving state or a convection state, is a “flowing state”. Also called. On the other hand, it is preferable that the picked-up image of the image pickup unit 110 clearly picks up the surface state of the molten slag that does not flow and is not blurred. Therefore, the exposure time is preferably set to a predetermined time according to the flow state of the molten slag.

  For example, when the molten slag ejection speed is 5 to 10 m / sec, the exposure time is preferably 1/5000 sec or less, more preferably 1/10000 sec or less. When the exposure time is 1/10000 sec, the output flow advances about 1 mm during exposure. The exposure time is not limited to these examples, and as described above, the exposure time is set to a time during which the surface state of the molten slag can be imaged without causing an image to flow. In addition, if the exposure time is too short, noise may occur in the image brightness due to insufficient light quantity, etc., and the temperature calculation accuracy may decrease, so the lower limit of the exposure time depends on the sensitivity of the condenser lens and image sensor, etc. Also depends.

  The imaging element forms an imaging surface, captures the heat radiation emitted from the outgoing stream 1, and converts it into an electrical signal corresponding to the luminance. That is, the magnitude of this electrical signal reflects the thermal radiance of the thermal radiation of the output stream 1. The magnitude of this electric signal is referred to herein as “density” or “intensity”, but is also referred to as “luminance (image luminance)” in the sense that it reflects luminance. The number of gradations of the density of the imaging element handled in a digitized manner is set according to, for example, the melt flow state, the viscosity, and the temperature measurement accuracy of the radiation temperature measuring device 100. For example, when the number of gradations is set to 256 gradations of 8 bits, a change in one gradation corresponds to a change of about 2 ° C. in temperature. The spatial resolution of the captured image captured by the imaging unit 110, that is, the number of pixels, depends on the number of imaging elements that form the imaging surface. This number of pixels is set to a value that can capture the surface state of the melt that is the object of temperature measurement. Note that various monochrome image sensors (not limited to monochrome) such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal-Oxide Semiconductor) can be used as the imaging device. An image picked up by the image pickup device is also referred to as a “captured image” or an “image”, and is also referred to as a “thermal image” in the sense that it is an image capturing thermal radiance. Each pixel in the captured image stores a density (image brightness) corresponding to the brightness of the emitted light captured by the corresponding image sensor as a value. That is, the density has a value corresponding to the luminance of the emitted light and is distributed in the captured image according to the position of each pixel (see FIG. 11). A histogram representing the distribution state of the number of pixels of each density gradation with respect to the magnitude of the density of the captured image is also referred to as a “thermal radiance histogram” or a “density histogram” (see FIG. 12). .) When a color image sensor is used, for example, when a pixel is composed of three colors of RGB, the density of one specific color or the average density of the three colors may be associated with the luminance of the emitted light. Obviously, other types of color image sensors may be used.

  The imaging unit 110 configured as described above is temperature calibrated using a black body furnace, and a set value such as an exposure time is fixed to a setting when the calibration is performed. The calibration of the imaging unit 110 will be described with reference to FIG. FIG. 8 is an explanatory diagram for explaining temperature calibration by the radiation temperature measuring device according to the present embodiment.

  First, for example, settings such as exposure time, lens aperture and focal length are adjusted according to the location of the imaging unit 110 and the imaging target (here, output flow 1). Then, the blackbody furnace (a reference radiation source having an emissivity of 1 that can control the temperature with high accuracy) is measured by the imaging unit 110. This measurement is performed while changing the temperature of the black body furnace. As a result, “calibration data” that correlates the relationship between the temperature of the black body furnace and the image luminance (density) when the radiance of the black body is imaged is measured. An example of the calibration data is shown in FIG. Further, from the calibration data, the calibration curve between the black body temperature and the image luminance (density) shown in FIG. 8 is fitted to a function having the argument as the image density and the output value as the black body temperature. Then, the calibration data fitted to the function is recorded in the calibration data storage unit 125. Note that the calibration data shown in FIG. 8 differs depending on the configuration of the imaging unit 110 and the set value. By performing such calibration, the imaging unit 110 can be used as a two-dimensional radiometer.

  The image processing unit 121 takes in the thermal image captured by the imaging unit 110 and performs a smoothing process on the thermal image using a spatial filter or the like. As the smoothing process, for example, the image processing unit 121 averages the density of each pixel of the thermal image with a plurality of adjacent pixels (for example, three pixels). By performing the smoothing process in this way, noise in the thermal image can be reduced. The thermal image that has been subjected to the smoothing process is output to the maximum luminance detection unit 123. Further, this thermal image may be recorded in the image data storage unit 122.

  At this time, the image processing unit 121 may detect the surface state of the molten slag. More specifically, for example, the image processing unit 121 extracts a region of the outgoing flow 1 from a thermal image as shown in FIG. 11, and the boundary between the region and another region (that is, an output including molten slag). Extract the surface of the torrent 1). Then, the image processing unit 121 may detect how much wave or unevenness is generated in the outgoing flow 1 from this boundary. Although the case where the magnitude of a wave or the like is detected from the boundary is described here, the image processing unit 121 detects the magnitude of the wave or the like directly from a thermal image representing the surface of the outgoing stream 1. It is also possible to do. The magnitude of the detected wave or the like is output to the temperature calculation unit 124 or recorded in the image data storage unit 122, and can be used in a temperature calculation process described later.

  The maximum luminance detection unit 123 detects the luminance with the highest radiance from the thermal image subjected to image processing by the image processing unit 121. That is, the maximum luminance detection unit 123 detects the highest density among the densities of the pixels corresponding to the luminance. In the example of the density histogram shown in FIG. 12, the highest density detected by the highest luminance detection unit 123 indicates a value with the highest image density on the horizontal axis. Here, the highest density is also referred to as “maximum image luminance Lmax” in the sense that it corresponds to the highest luminance.

  The maximum luminance detection unit 123 may detect the maximum image luminance Lmax from one thermal image, but a plurality of continuous (imaged in a short time) recorded in the image data storage unit 122. From the image, the highest density over the plurality of thermal images may be detected as the maximum image luminance Lmax. As will be described below, the radiation temperature measuring device 100 calculates the temperature of the temperature measurement object based on the maximum image luminance Lmax (maximum density), but the maximum luminance detection unit 123 determines the maximum image luminance Lmax from a plurality of thermal images. By detecting this, the temperature measurement accuracy of the molten slag can be further improved.

  The temperature calculation unit 124 calculates the temperature of the molten slag as an example of the temperature measurement object based on the highest image luminance Lmax (an example of the highest luminance, also referred to as the highest density) detected by the highest luminance detection unit 123. At this time, the temperature calculation unit 124 uses the calibration data of the imaging unit 110 stored in advance in the calibration data storage unit 125 and 0.96 as the apparent emissivity E of the molten slag at the maximum image luminance Lmax. The value of molten slag is calculated using any value of ~ 1. That is, as described in the above conditions 1 and 2, the temperature calculation unit 124 can assume that the apparent emissivity E with respect to the maximum image luminance Lmax of the molten slag is any value between 0.96 and 1. ”Is used to calculate the temperature T of the molten slag.

More specifically, the temperature calculation unit 124 first illustrated the melted slag black body temperature (apparent temperature when the melted slag is assumed to be a black body) T _b from the maximum image luminance Lmax as illustrated in FIG. Calculate based on calibration data. Then, based on the emissivity E set for the molten slag, the true molten slag temperature T is calculated by the following equation 18. In Equation 18, the black body temperature _Tb and the true molten slag temperature T are handled as absolute temperatures. If the emissivity of the molten slag at the maximum image luminance Lmax and 1, temperature calculating unit 124 calculates the black body temperature T _b by substituting the maximum image luminance Lmax (maximum density) in the function of the calibration data, it It is set as the temperature T of molten slag.

  When calculating the temperature T of the molten slag, the temperature calculation unit 124 uses any value of 0.96 to 1 as the apparent emissivity E with respect to the maximum image luminance Lmax as described above. At this time, the emissivity E may be set in advance to an appropriate value, but it is desirable that the emissivity E is selected as follows, for example.

  For example, the temperature calculation unit 124 can simply set the apparent emissivity E to 1. As described in the above conditions 1 and 2, the apparent emissivity E can be regarded as 0.96 because the molten slag is translucent, and further approaches 1 if a wave exists. Even if the emissivity E is set to 1, even if the reflected light is not included and the actual apparent emissivity E is about 0.96, the measurement error in this case is about 5 ° C., which is practical. An allowable temperature measurement is possible. On the other hand, as can be seen from FIG. 7, the apparent emissivity E is 0.998 which is very close to 1 just by including the primary reflected light Ir1, and thus the emissivity E is set to 1 in this way. Therefore, temperature measurement with higher accuracy becomes possible.

  Note that it is also conceivable that the image pickup unit 110 picks up a picked-up image in which the wave of the outgoing stream 1 is small and there is no portion where multiple reflection occurs so that the emissivity E can be regarded as 1. Therefore, the maximum luminance detection unit 123 detects the maximum image luminance Lmax over a plurality of captured images that are captured in a short time and recorded in the image data storage unit 122, so that the temperature calculation unit 124 can detect the apparent emissivity E. Can increase the probability of multiple reflections sufficient to approach 1 and improve temperature measurement accuracy. This also applies to Condition 1. That is, it is conceivable that the imaging unit 110 captures a captured image in which the molten slag is thin and the flat surface emissivity ε is smaller than 0.96. Also in this case, the maximum luminance detection unit 123 detects the maximum image luminance Lmax over a plurality of captured images that are captured in a short time and recorded in the image data storage unit 122, so that the temperature calculation unit 124 can detect the flat surface. The probability of emissivity ε approaching 0.96 can be increased, and the temperature measurement accuracy can be improved.

  For example, when the image processing unit 121 detects the surface state of the molten slag, the temperature calculation unit 124 sets the emissivity E to a value corresponding to the magnitude of the wave generated on the surface of the molten slag. It is also possible to do. In this case, for example, the magnitude of the wave that can include the reflected light is measured in advance as a threshold value, and the temperature calculation unit 124 reflects the reflected light based on the threshold value and the magnitude of the wave detected by the image processing unit 121. Determine the presence or absence. The temperature calculation unit 124 can set the emissivity E to 0.96 when the reflected light is not included, and can set the emissivity E to 1 when the reflected light is included. is there. When measuring a temperature measuring object whose flat surface emissivity ε is not close to 0.96 and 1 such as molten slag, as shown in FIG. 6, the apparent emissivity E is the reflection of the reflected light contained therein. It changes in stages according to the number of times. Therefore, it is also possible to set a threshold value for selecting reflected light with respect to the molten slag for each number of reflections of the included reflected light, and allow the temperature calculation unit 124 to adjust the emissivity E step by step. It is of course possible to change the reflectance E continuously as in the case of adjusting stepwise.

With reference to FIG. 1, another configuration of the radiation temperature measuring device 100 will be described as follows.
The display unit 131 displays the temperature T of the molten slag calculated by the temperature calculation unit 124. As described above, the temperature T of the molten slag is substantially equal to the temperature of the hot metal discharged from the same hot water pool, and also reflects the temperature of the hot water pool immediately after being discharged from the hot water pool of the blast furnace. ing. Therefore, according to the radiation temperature measuring device 100, the temperature of the hot water pool can be measured more accurately. Further, the temperature T of the molten slag calculated by the temperature calculation unit 124 may be recorded in the temperature data storage unit 132. The radiation temperature measuring device 100 can repeat the measurement at a very short time interval on the order of seconds compared to the intermittent temperature measurement of the contact-type temperature measuring device according to the related art. Therefore, by recording the measured temperature T in the temperature data storage unit 132, the temperature change inside the blast furnace can be continuously measured.

(2-3. Operation of the radiation temperature measuring device 100)
Next, operation | movement of the radiation temperature measuring apparatus 100 which concerns on this embodiment is demonstrated, referring FIG. FIG. 9 is an explanatory diagram for explaining the operation of the radiation temperature measuring device according to the present embodiment.

  First, Step S01 is processed, and the imaging unit 110 captures the radiation light thermally radiated from the outgoing stream 1 including the molten slag that is a temperature measurement target. This captured image is output to the image processing unit 121. Then, the process proceeds to step S03.

  In step S03, the image processing unit 121 performs the above-described smoothing process on the captured image. Then, the image processing unit 121 outputs the captured image to the maximum luminance detection unit 123 and records it in the image data storage unit 122. In step S03, it is desirable that the image processing unit 121 also detects the surface state of the molten slag, that is, the size of the wave (concave portion). Then, the process proceeds to step S05.

  In step S05, the maximum luminance detecting unit 123 outputs one captured image output from the image processing unit 121 or a plurality of captured images (short) recorded in the image data storage unit 122 including the one captured image. A maximum image luminance Lmax corresponding to the maximum luminance is detected from a plurality of captured images captured in time). As described above, the maximum image luminance Lmax is the direct light I0 having a flat surface emissivity ε depending on the thickness of the molten slag and the reflected light Iri depending on the surface state (i is a natural number representing the number of reflections of the radiated light). It is desirable to include the direct light I0 from the relatively thick molten slag and the reflected light Iri that has undergone multiple reflection. Therefore, when the maximum luminance detection unit 123 detects the maximum image luminance Lmax from a plurality of captured images, it seems that the direct light I0 from the relatively thick molten slag and the reflected light Iri reflected many times are more included. The probability that the luminance is captured in the captured image can be increased, and the temperature measurement accuracy of the radiation temperature measuring device 100 can be improved. Next, the process proceeds to step S07.

  In step S <b> 07, the apparent emissivity E is set by the temperature calculation unit 124. At this time, the temperature calculation unit 124 can simply set a pre-set value (for example, 1) as the emissivity E, but further sets the magnitude of the wave detected in step S03. It is also possible to set a corresponding value to the emissivity E. Next, the process proceeds to step S09.

In step S09, the temperature calculating unit 124 calculates the blackbody temperature T _b on the basis and a maximum image luminance Lmax of the maximum luminance detector 123 detects, on the function of the calibration data illustrated in FIG. Then, the temperature T of the molten slag is calculated by substituting the black body temperature _Tb and the emissivity E into Equation 18. Then, the process proceeds to step S11.

  In step S <b> 11, the temperature T of the molten slag calculated by the temperature calculation unit 124 is displayed on the display unit 131 and recorded in the temperature data storage unit 132. At this time, it goes without saying that the display unit 131 may display the temperature change over time as a history. Then, the process proceeds to step S13.

  In step S13, the radiation temperature measuring device 100 confirms whether or not temperature measurement is stopped. For example, the temperature measurement may be automatically stopped in accordance with a command value, a user input value, a blast furnace output state, etc., by a higher-order control device of the radiation temperature measuring device 100. And when temperature measurement is stopped, the radiation temperature measuring device 100 complete | finishes operation | movement, and when temperature measurement is not stopped, the radiation temperature measuring device 100 repeats the process after said step S01. Do. Therefore, the radiation temperature measuring device 100 can continuously image the temperature T of the molten slag. In addition, the radiation thermometer 100 can also repeat the process of step S01-step S10, for example once or more per second.

(2-4. Measurement example using radiation temperature measuring device 100)
Next, a measurement example of the radiation temperature measuring device 100 according to the present embodiment will be described with reference to FIG. FIG. 10 is an explanatory diagram for explaining a measurement example by the radiation temperature measuring device according to the present embodiment. Here, with respect to the blast furnace in operation, the temperature T of the molten slag discharged from the tap outlet 10 was measured by the radiation temperature measuring device 100 according to the present embodiment. Further, in order to compare the performance of the radiation temperature measuring device 100, a thermocouple which is a contact type temperature measuring device according to related technology is immersed in the output flow 1 downstream of the output 12. Flow 1 temperature measurements were taken. It is expected that the temperature of the outgoing stream 1 and the temperature T of the molten slag are substantially equal.

  In addition, as a thermocouple, the R thermocouple normally used (Immersion consumption type thermocouple currently used by operation) was used. In addition, as the image pickup unit 110, a monochrome CCD camera was used, and high-speed exposure was performed with a high-speed shutter exposure time of 1/10000 second. In addition, the number of gradations of the image pickup device was 256 gradations of 8 bits. Then, the light of λ = 0.65 was transmitted by the wavelength selection filter and imaged by the image sensor. The imaging unit 110 was temperature calibrated in advance in a black body furnace, and calibration data was recorded in the calibration data storage unit 125 (see FIG. 8). Further, 1 was used as the apparent emissivity E with respect to the maximum image luminance Lmax used when obtaining the temperature T of the molten slag.

  The radiation temperature measuring device 100 continuously measures the temperature at predetermined time intervals for about 3 hours from the start of the blast furnace discharge, while intermittently measuring the temperature at intervals of about 30 minutes with a thermocouple. Went. Moreover, as shown in FIG. 1, the imaging part 110 imaged the jet of the hot metal / molten slag discharged from the blast furnace outlet 10 from the lateral direction. As a result, a thermal image as shown in FIG. 11 was taken.

  The history of the temperature measurement result of the radiation temperature measuring device 100 is shown in FIG. When the display unit 131 displays the history as a graph, the graph shown in FIG. 10 may be displayed. In FIG. 10, together with the temperature measurement result by the radiation temperature measuring device 100, the measurement result by the thermocouple is displayed for comparison. As shown in FIG. 10, it was confirmed that the temperature measurement result of the radiation temperature measuring device 100 and the temperature measurement result of the thermocouple coincide with each other with high accuracy. That is, it can be seen that the radiation temperature measuring device 100 according to the present embodiment can accurately measure the temperature T of the molten slag. Moreover, compared with the measurement by a thermocouple, the radiation temperature measuring device 100 can perform continuous temperature measurement.

(2-5. Example of effect by radiation temperature measuring device 100)
The radiation temperature measuring device 100 according to the embodiment of the present invention has been described above. According to this radiation temperature measuring device 100, by calculating the temperature T from the maximum image luminance Lmax, it is possible to accurately measure the temperature T of the molten slag, which is an example of a melt with a wavy surface. At this time, the radiation temperature measuring device 100 does not need to know the exact emissivity ε of the molten slag. Although the radiation temperature measuring device of the above-mentioned Patent Document 1 related to the related art is difficult to measure the temperature of the outflow 1 if there is no outflow of hot metal, the radiation temperature measuring device 100 according to the present embodiment, the molten slag By measuring the temperature T, it is also possible to measure the temperature of the tapping stream 1 (for example, about several tens of minutes after the start of tapping) that does not contain much hot metal. Moreover, since the radiation temperature measuring device 100 can measure temperature continuously, it can measure the time change of the temperature inside a blast furnace. Therefore, more information can be obtained about the thermal condition inside the blast furnace, and the operation of the blast furnace can be further stabilized. At this time, in the radiation temperature measuring device 100, the flat surface emissivity ε of molten slag, which is an example of a melt, approximates 0.96. The radiation temperature measuring device 100 approximates the apparent emissivity E to 1 when the surface of the molten slag is greatly rippled. As a result, measurement error can be reduced. Therefore, the radiation temperature measuring device 100 can not only measure the temperature of the melt that is significantly waved, but can also improve the temperature measurement accuracy by using the significant wave that was difficult to measure with related technology. Can do. Further, at this time, the radiation temperature measuring device 100 is used not only in the case where the molten slag occupies most as in the beginning of the start of brewing, but also in the state where the molten slag is mixed non-uniformly with the molten iron and becomes turbid. It is possible to detect temperature and measure temperature.

  Furthermore, the radiation temperature measuring device 100 according to the present embodiment does not need to be arranged in the vicinity of the tap hole 10 and can remotely measure the temperature T of the molten slag from a certain distance away. Environmental measures against thermal radiation of the stream 1 and splash scattering are simple. In addition, since the radiation temperature measuring device 100 can measure the temperature of the molten slag immediately after being fed from the tap 10, it can be used in the furnace rather than the thermocouple according to the related technology for measuring downstream of the tap 12. The temperature of the molten slag close to the temperature can be measured.

  As mentioned above, although preferred embodiment of this invention was described in detail, referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

  For example, in the above-described embodiment, the molten slag has been described as an example of the flowing melt that is a temperature measurement target, but the present invention is not limited to such an example. The case where the temperature measurement object other than the molten slag is measured will be described as follows.

  In the above embodiment, the apparent emissivity E with respect to the maximum image luminance Lmax corresponding to the maximum luminance of the thermal radiation emitted from the molten slag was approximated to 0.96-1 based on the conditions 1 and 2. On the other hand, the inventors of the present invention can measure the temperature similarly for the temperature measurement object other than the molten slag by using the maximum image luminance Lmax based on the consideration on the characteristics 1 and 2 of the molten slag. I found out. In this case, the above conditions 1 and 2 can be rephrased as the following conditions 3 and 4, respectively.

Condition 3: When the temperature measurement target transmits at least part of the thermal radiance, that is, when the temperature measurement target is optically translucent or transparent, the reflection loss ln at the interface with the temperature measurement target air Then, from Equation 11, the apparent emissivity (flat surface emissivity) ε at the maximum image luminance Lmax can be regarded as (1-ln).
Condition 4: When the surface of the temperature measurement object is in a wavy state, that is, when there is a concave portion on the surface of the temperature measurement object, the captured image contains single or multiple reflected light, so that the maximum image brightness The apparent emissivity E at Lmax is closer to 1 than the flat surface emissivity ε of condition 3 (the true emissivity if condition 1 is not satisfied).

  The same applies to the molten slag of the above embodiment, but the temperature measurement object does not necessarily satisfy both of the above conditions 3 and 4 (conditions 1 and 2). If either one is satisfied, the highest image is obtained. It becomes possible to approximate the apparent emissivity E with respect to the luminance Lmax to a predetermined value. For example, when the temperature measurement object is optically translucent but the surface is flat, that is, when the condition 3 is satisfied but the condition 4 is not satisfied, the radiation temperature measuring device 100 is It is possible to approximate the apparent emissivity E with respect to the maximum image luminance Lmax of the temperature measurement object to (1-ln). Conversely, for example, if the temperature measurement object is neither optically transparent nor translucent, but the surface is in a wavy state, that is, if condition 3 is not satisfied, but condition 4 is satisfied, The radiation thermometer 100 can approximate the apparent emissivity E with respect to the maximum image luminance Lmax to 1 from condition 4 even if the true emissivity of the temperature measurement object is not specified in advance.

  A case where the condition 4 is not satisfied and the condition 4 is satisfied will be described with an example. Temporarily, for a temperature measurement object whose true emissivity ε fluctuates in the vicinity of 0.7, the radiation temperature measuring device 100 approximates the apparent emissivity E with respect to the maximum image luminance Lmax corresponding to the maximum luminance to 1 and the temperature. Is measured. In this case, if the emissivity ε changes by ± 0.1, the measurement error is about ± 20 ° C., which is not practically acceptable. On the other hand, when the ripple has occurred as described above, the maximum image luminance Lmax is used, and 1 is used as the apparent emissivity E, the maximum image luminance Lmax includes single or multiple reflected light. It is. As can be seen from FIG. 6, the apparent emissivity E is 0.97 when the secondary reflected light is included. In this case, if the apparent emissivity E is set to 1, the measurement error is about 5 ° C., and a practically acceptable accuracy can be secured. Therefore, the closer the true emissivity ε of the temperature measurement object is to 1, the closer the apparent emissivity E for the maximum image luminance Lmax is to 1, but even if the true emissivity ε can be approximated to 1, it becomes 1 Even if it is not close, if the primary reflected light, the secondary reflected light, and the multiple reflected light overlap, the apparent emissivity E with respect to the maximum image luminance Lmax can be approximated to 1 to measure the temperature accurately. Is possible.

  In the case where the above condition 3 is satisfied, the radiation temperature measuring device 100, from the conditions 3 and 4, the apparent emissivity E with respect to the maximum image luminance Lmax of the temperature measurement object, as in the molten slag described in the above embodiment. Is approximated to any value from (1-ln) to 1, regardless of whether the condition 4 is satisfied or not, it is possible to improve the temperature measurement accuracy.

  In addition, the radiation temperature measuring device 100 can also measure various meltings that flow as turbulent flow in which irregularities occur on the liquid surface. That is, the radiation temperature measuring device 100 can measure various melts as long as the melt is optically translucent or transparent, or the melt has a wavy surface. At this time, the molten material has a certain degree of viscosity like a molten slag, and the more unevenness and the bulge are in the surface state, the more multiple reflections can be generated, so that the temperature measurement accuracy can be improved. Further, the accurate emissivity ε of the melt itself may be unknown as described above, but if the value is close to 1 to some extent, more accurate temperature measurement is possible. Further, even if the melt is a mixture of a plurality of melts as in the above-described outgoing stream 1, the temperature can be measured. In this case, it is desirable that the mixed melts are imaged separately in a marble shape, and the radiation temperature measuring device 100 measures the temperature of the melt having the higher emissivity in the mixed melt. By doing so, it is possible to measure the temperature of the mixed melt.

  Further, for example, the series of processes described in the above embodiments may be executed by dedicated hardware, but may be executed by software. When the series of processes is performed by software, the above series of processes can be realized by causing a general-purpose or dedicated computer to execute the program. The computer includes a CPU (Central Processing Unit), a recording device such as a HDD (Hard Disk Drive), a ROM (Read Only Memory), a RAM (Random Access Memory), a LAN (Local Area Network), etc. Communication devices, input devices such as mouse / keyboard, flexible disks, optical disks such as various CDs (Compact Discs), MO (Magneto Optical) disks, DVDs (Digital Versatile Discs), magnetic disks, semiconductor memories, etc. Drives that read and write removable recording media, etc., and display devices such as monitors, audio output such as speakers and headphones An output device such as a force device. The computer may execute the above-described series of processes by executing a program recorded on a recording device / removable recording medium or a program acquired via a network.

DESCRIPTION OF SYMBOLS 1 Outflow 10 Outlet 11 Through-hole 12 Outlet 13 樋 Cover 100 Radiation temperature measuring device 110 Imaging part 121 Image processing part 122 Image data storage part 123 Maximum brightness detection part 124 Temperature calculation part 125 Calibration data storage part 131 Display unit 132 Temperature data storage unit Sl Melting slag Me Hot metal S Surface Lmax Maximum image brightness

Claims (12)

An emissivity is not specified in advance, a radiation temperature measuring device that measures the temperature of a temperature measurement object that is a melt that transmits at least part of the heat radiation light,
An imaging unit for imaging a distribution of thermal radiance of the thermal radiation emitted from the temperature measurement object;
A maximum brightness detection unit for detecting the maximum brightness in a captured image captured by the imaging unit;
A temperature calculation unit that calculates the temperature of the temperature measurement object based on the highest luminance detected by the highest luminance detection unit;
Have
The temperature calculation unit is any one of (1-ln) to 1 as the emissivity of the temperature measurement object at the highest luminance, where ln is a reflection loss of the interface with the atmosphere of the temperature measurement object with respect to the thermal radiation light. The temperature of the temperature measuring object is calculated using the value of the radiation temperature measuring device.   When the temperature measurement object is a molten slag included in the tidal stream output from the blast furnace, the temperature calculation unit is any one of 0.96 to 1 as the emissivity of the temperature measurement object at the highest luminance The temperature measuring device according to claim 1, wherein the temperature of the molten slag is calculated using a value.   The said temperature calculation part uses the value according to the magnitude | size of this wave as said emissivity, when the surface of the said temperature measurement object is a state with a wave. Radiation thermometer.   The temperature calculation unit calculates the temperature of the temperature measurement object using 1 as the emissivity of the temperature measurement object at the highest luminance when the surface of the temperature measurement object is in a rippled state. The radiation temperature measuring device according to any one of claims 1 to 3, wherein the radiation temperature measuring device is characterized.   5. The radiation temperature measuring device according to claim 1, wherein the maximum luminance detection unit detects the maximum luminance over a plurality of captured images captured by the imaging unit.   The radiation temperature measuring device according to claim 1, wherein the imaging unit includes a high-speed shutter that exposes the imaging device for a predetermined time according to a flow state of the temperature measurement target. A radiation temperature measurement method for measuring a temperature of a temperature measurement object that is a melt that transmits at least part of heat radiation light, the emissivity is not specified in advance,
An imaging step of imaging a distribution of thermal radiance of the thermal radiation emitted from the temperature measurement object;
A maximum luminance detection step for detecting the maximum luminance in the captured image captured in the imaging step;
A temperature calculating step for calculating a temperature of the temperature measuring object based on the highest luminance detected in the highest luminance detecting step;
Have
In the temperature calculation step, if the reflection loss at the interface with the temperature measurement target atmosphere with respect to the thermal radiation light is ln, the emissivity of the temperature measurement target at the highest luminance is any one of (1-ln) to 1. A radiation temperature measurement method, wherein the temperature of the temperature measurement object is calculated using a value of.   In the temperature calculation step, when the temperature measurement object is a molten slag included in the outgoing stream discharged from a blast furnace, the emissivity of the temperature measurement object at any one of 0.96 to 1 at the highest luminance The temperature measuring method according to claim 7, wherein the temperature of the molten slag is calculated using a value.   The temperature calculation step uses a value corresponding to the magnitude of the wave as the emissivity when the surface of the temperature measurement object is in a wavy state. Radiation temperature measurement method.   In the temperature calculation step, when the surface of the temperature measurement object is in a wavy state, the temperature measurement object temperature is calculated using 1 as the emissivity of the temperature measurement object at the highest luminance. The radiation temperature measuring method according to any one of claims 7 to 9, characterized by the above.   The radiation temperature measurement method according to any one of claims 7 to 10, wherein, in the maximum luminance detection step, the maximum luminance over a plurality of captured images captured by the imaging unit is detected.   The radiation temperature measuring method according to claim 7, wherein in the imaging step, the imaging element is exposed for a predetermined time according to a flow state of the temperature measurement object by a high-speed shutter.