Furnace monitoring structure, boiler equipped with the same, monitoring system, and inspection method

Abstract

To provide an in-furnace monitoring structure that can image a furnace interior with a simple and inexpensive configuration, and to provide a boiler including the same, a monitoring system and an inspection method.SOLUTION: An in-furnace monitoring structure 100 includes: a pinhole member 110 made of a heat insulation material, installed on an outside of a furnace wall 150 which is formed with a furnace wall through-hole 151, and formed with a pinhole 111 for viewing an interior of the furnace wall 150 via the furnace wall through-hole 151; and an imaging part 140 for imaging the interior of the furnace wall 150 via the furnace wall through-hole 151 and the pinhole 111.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to an in-furnace monitoring structure, a boiler equipped with the same, a monitoring system, and an inspection method.

Background Art

[0002] In a high-temperature furnace that operates continuously for thousands of hours, such as a boiler in a power plant, it is necessary to observe the high-temperature furnace interior during operation to confirm its soundness.

[0003] The furnace wall of a boiler is in the form of a so-called membrane wall in which heat transfer tubes through which high-pressure saturated water flows are arranged in panels to function as a steam generator. It is not easy to retroactively install an observation structure after the furnace wall is fabricated. For this reason, in order to observe the furnace interior, it is preferable to install a viewing window in the furnace wall in advance (for example, Patent Document 1), or to prepare a pipe stand for inserting a camera.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in order to address troubles that occur after starting operation, introduce a new monitoring system, or implement maintenance and inspection methods, it may be necessary to observe positions that were not assumed during design. In such cases, for example, a method of adding a peephole as disclosed in Patent Document 1 can be considered, but this involves large-scale construction and is not preferable in terms of cost. As another method, a method of observing the inside of the furnace using a heat-resistant borescope can be considered, but heat-resistant borescopes are expensive and not preferable in terms of cost. Also, when introducing AI into a new monitoring system, long-term observation is desirable to secure learning data, but heat-resistant borescopes are not suitable for long-term installation.

[0006] In addition, in any method, it is necessary to install a camera or the like near the flame. In this case, it is necessary to also install a cooling system and an air system for purging deposits such as ash, and there is a concern about the complication of the structure.

[0007] Furthermore, in order to avoid the influence of radical emission and fine particles of the flame, it is desirable to perform observation in the infrared wavelength range. Considering the transmission of infrared rays, it is preferable that the window material and lens material are made of sapphire. This is because sapphire transmits infrared rays more easily than ordinary quartz glass. However, sapphire is more expensive than quartz glass and is not preferable in terms of cost.

[0008] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a furnace internal monitoring structure, a boiler equipped with the same, a monitoring system, and an inspection method that can photograph the inside of the furnace with a simple and inexpensive configuration.

Means for Solving the Problems

[0009] In order to solve the above problems, the furnace internal monitoring structure, the boiler equipped with the same, the monitoring system, and the inspection method of the present disclosure employ the following means. That is, the in-furnace monitoring structure according to one aspect of the present disclosure is installed outside a furnace wall in which a through-hole is formed, and a pinhole member made of a non-metallic heat insulating material having a pinhole formed therethrough for seeing inside the furnace wall through the through-hole, a photographing unit for photographing inside the furnace wall through the through-hole and the pinhole, and a stainless steel housing that contacts the pinhole member outside the furnace wall, houses the photographing unit, and has an accommodation space formed therein that communicates with the pinhole. A gas supply unit capable of supplying gas to the accommodation space, and includes , the gas supply unit is provided with a pressure measurement unit capable of adjusting the pressure of the supplied gas and measuring the pressure of the accommodation space, and a control unit for controlling the pressure of the gas supplied from the gas supply unit based on information from the pressure measurement unit .

[0010] In addition, a boiler according to one aspect of the present disclosure includes the above-described in-furnace monitoring structure and the furnace wall in which a plurality of heat transfer tubes are arranged in a panel shape.

[0011] Further, a monitoring system according to one aspect of the present disclosure includes the above-described in-furnace monitoring structure and a processing unit that acquires and processes information from the photographing unit of the in-furnace monitoring structure.

[0012] Moreover, an inspection method according to one aspect of the present disclosure includes a step of performing monitoring using information acquired from the photographing unit of the above-described in-furnace monitoring structure.

Advantages of the Invention

[0013] According to the present disclosure, it is possible to provide an in-furnace monitoring structure capable of photographing the inside of a furnace with a simple and inexpensive configuration, and a boiler including the same. In addition, it is possible to provide maintenance and inspection using information obtained from the in-furnace monitoring structure, as well as a monitoring system and AI.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0015] [First Embodiment] Hereinafter, the in-furnace monitoring structure according to the first embodiment of the present disclosure will be described with reference to FIGS. 1 to 5.

[0016] FIG. 1 is a cross-sectional view of the in-furnace monitoring structure 100 as viewed from the side. FIG. 2 is a cross-sectional view of the in-furnace monitoring structure 100 as viewed from the plane. FIG. 3 is a diagram showing the gas flow in FIG. 1. FIG. 4 is a cross-sectional view taken along the cutting line IV-IV shown in FIG. 3. FIG. 5 is a cross-sectional view taken along the cutting line V-V shown in FIG. 4.

[0017] As shown in FIGS. 1 and 2, the in-furnace monitoring structure 100 includes a pinhole member 110, a housing 120, and a photographing unit 140, and is connected to the furnace wall 150.

[0018] Hereinafter, the furnace wall 150 will be described. The furnace wall 150 is a so-called membrane wall in which a plurality of heat transfer tubes are arranged in a panel shape, and is, for example, the furnace wall of a high-temperature furnace such as a boiler. In the figure, the left side of the furnace wall 150 is the inside of the furnace (for example, the inside of the boiler), and the right side of the furnace wall 150 is the outside of the furnace.

[0019] A furnace wall through-hole (through-hole) 151 communicating with the inside of the furnace is formed in the furnace wall 150.

[0020] On the outer side of the furnace wall 150, a heat insulating material 152 with a predetermined thickness is provided. The heat insulating material 152 covers all of the pinhole member 110 and a part of the housing 120. The heat insulating material 152 is, for example, rock wool or the like.

[0021] Hereinafter, each component of the in-furnace monitoring structure 100 will be described. The pinhole member 110 is a thick plate member made of a heat insulating material. The heat insulating material used for the pinhole member 110 is non-metallic and is difficult to undergo thermal deformation (thermal elongation, thermal expansion, etc.), and is, for example, alumina fiber, ceramic, etc., but alumina fiber is more preferable. The pinhole member 110 is fixed in a state where the front surface 112 faces the outer side of the furnace wall 150. At this time, the front surface 112 of the pinhole member 110 may or may not be in contact with the furnace wall 150, but it is also possible to position the pinhole member 110 with respect to the furnace wall 150 by making contact a construction requirement during installation. A pinhole 111 is formed in the pinhole member 110 at a position where the furnace wall through-hole 151 can be seen through, and the inside of the furnace can be seen through the furnace wall through-hole 151 from the pinhole 111. The position where the furnace wall through-hole 151 can be seen through is, for example, a position where the furnace wall through-hole 151 and the pinhole 111 have a common axis when the pinhole member 110 is installed with respect to the furnace wall 150.

[0022] The pinhole 111 is a tapered through-hole that tapers toward the inside of the furnace, and the inner diameter of the tip on the inside of the furnace is a micro-hole of about 1 mm to 2 mm.

[0023] The housing 120 is a box-shaped member, and an accommodation space 121 is formed inside. The material of the box-shaped member is preferably one that has no risk of deformation or ignition even in the event of a coolant stop, and is preferably one that has durability against the vibration of the furnace during operation and does not cause deterioration of heat transfer performance due to corrosion during long-term use. As an example of a material that satisfies this condition, stainless steel can be exemplified. The accommodation space 121 communicates with the pinhole 111 through the housing through-hole 126. The photographing unit 140 described later is accommodated in the accommodation space 121. The housing 120 is joined to the back surface 113 side of the pinhole member 110. The housing 120 and the pinhole member 110 are joined by, for example, an adhesive. The detailed configuration of the housing 120 will be described later.

[0024] As shown in FIG. 1, the photographing unit 140 is a device capable of photographing the inside of the furnace wall 150 through the furnace wall through-hole 151 and the pinhole 111. That is, the photographing unit 140 functions like a so-called pinhole camera. The photographing unit 140 has a camera 141 and mirrors 142, 143, 144.

[0025] The mirror (one mirror) 142 is disposed in the accommodation space 121 at a position where the light inside the furnace that has entered through the furnace wall through-hole 151 and the pinhole 111 directly hits. Specifically, the mirror 142 is disposed behind the pinhole 111 in the penetrating direction (light traveling direction) of the pinhole 111. Note that the "light" mentioned here includes not only visible light but also infrared rays (the same applies hereinafter).

[0026] The mirrors (other mirrors) 143 and the mirrors (other mirrors) 144 are disposed in the accommodation space 121 at positions where the light inside the furnace that has entered through the furnace wall through-hole 151 and the pinhole 111 does not directly hit. Specifically, the mirror 143 is disposed above the mirror 142. Also, the mirror 144 is disposed behind the mirror 143 in the penetrating direction (light traveling direction) of the pinhole 111.

[0027] The camera 141 is disposed in the accommodation space 121 at a position where the light in the furnace entering through the furnace wall through-hole 151 and the pinhole 111 does not directly strike, and behind the mirror 142 in the penetration direction (light traveling direction) of the pinhole 111. As a result, since the thermal influence transmitted from the furnace interior through the furnace wall through-hole 151 and the pinhole 111 is shielded by the mirror 142, the camera 141 will be protected from the thermal influence.

[0028] The mirrors 142, 143, and 144 are arranged so that the light entering from the pinhole 111 is guided to the camera 141. Specifically, the mirror 142 is a concave mirror and reflects the light entering from the pinhole 111 toward the upper mirror 143. The mirror 143 is a plane mirror and reflects the light reflected by the mirror 142 toward the rear mirror 144. The mirror 144 is a concave mirror and condenses the light while reflecting the light reflected by the mirror 143 toward the lower camera 141. The camera 141 is of a type capable of infrared imaging, is arranged to correspond to the focal position of the concave mirror 144, and receives the light reflected by the mirror 144 to perform imaging. The image / video captured by the camera 141 is displayed on, for example, a monitor monitored by an operator after appropriate processing by a processing unit (not shown) of the control device 163. As a result, it becomes possible to photograph and monitor the interior of the furnace like a so-called pinhole camera.

[0029] Note that the arrangement of the camera 141 and the mirrors 142, 143, 144, the types of the camera and the mirrors, and the number of mirrors used can be appropriately changed according to the specifications. For example, a convex mirror may be employed instead of the concave mirror.

[0030] Also, the camera 141 is preferably spaced apart from the furnace wall 150 in order to avoid thermal influence, but is preferably arranged at an appropriate position in consideration of the light intensity.

[0031] As shown in FIG. 3, the furnace interior monitoring structure 100 may include a gas supply unit 161. The gas supply unit 161 is a device that can supply gas to the accommodation space 121 formed by the housing 120. As the gas to be supplied, an inert gas is preferable, and for example, air, nitrogen, argon, etc. are used.

[0032] The supplied gas fills the accommodation space 121, and the gas in the accommodation space 121 jets out from the pinhole 111 toward the furnace interior. Thereby, the gas acts as a purge gas that suppresses the phenomenon that particles in the furnace enter from the pinhole 111. At the same time, since a gas flow is generated in the accommodation space 121, the camera 141 can be cooled by that flow.

[0033] The gas supply unit 161 can control the pressure of the gas to be supplied. Further, the furnace interior monitoring structure 100 includes a pressure gauge (pressure measurement unit) 162 that measures the pressure of the accommodation space 121. Thereby, the pressure of the gas in the accommodation space 121 can be controlled. Acquisition of the pressure and control of the gas supply unit 161 are executed by a pressure control unit (control unit) (not shown) that the control device 163 included in the furnace interior monitoring structure 100 has.

[0034] The control device 163 is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and a computer-readable storage medium, etc. And a series of processes for realizing various functions are stored in a storage medium etc. in the form of a program as an example. The CPU reads this program into the RAM etc. and executes information processing and arithmetic processing, whereby various functions are realized. At this time, the processed and arithmetically processed information may be used as AI learning data after being associated with the progress of troubles etc. Here, the AI has a function of implementing or assisting operations leading to maintenance and inspection of the boiler or the monitoring device, such as abnormality detection, prevention of troubles, improvement of operating conditions, etc. Note that the program may be applied in the form of being pre-installed in a ROM or other storage medium, in the form of being provided in a state stored in a computer-readable storage medium, in the form of being distributed via wired or wireless communication means, etc. A computer-readable storage medium includes a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, etc.

[0035] By controlling the pressure of the gas in the accommodation space 121, the purge amount of the gas ejected from the pinhole 111 can be adjusted.

[0036] In the above description, the purge amount of the gas is adjusted based on the information obtained from the pressure gauge 162, but the purge amount of the gas may be adjusted by obtaining the differential pressure with the inside of the furnace.

[0037] Note that it is also possible to directly measure the flow rate and adjust the purge amount, but since the pinhole 111 is a micro hole and the amount of gas ejected is very small, it is not suitable for high-precision adjustment.

[0038] Next, the details of the housing 120 will be described. As shown in FIG. 3, the housing 120 has a plurality of flow paths 122, 123, 124, 125 between the inner surface and the outer surface. Specifically, the housing 120 has an upper flow path 122, a lower flow path 123, a front flow path 124, and a side flow path 125.

[0039] The upper flow path 122 is a flow path formed on the upper surface side of the housing 120, and is a flow path having a substantially U-shaped cross-sectional shape configured such that the gas supplied from the air supply header 122A is turned back at the tip of the housing 120 (the end on the side of the pinhole member 110) and then flows to the exhaust header 122B. By flowing the gas in this way, the housing 120 is cooled.

[0040] Gas is supplied to the air supply header 122A from a gas supply device (not shown). Also, gas may be supplied to the air supply header 122A from the gas supply unit 161.

[0041] Similarly, the lower channel 123 is a channel formed on the lower surface side of the housing 120, and is configured such that the gas supplied from the air supply header 123A flows to the exhaust header 123B after being turned back at the tip of the housing 120 (the end on the pinhole member 110 side). It is a channel having a substantially U-shaped cross-sectional shape. By the gas flowing in this way, the housing 120 is cooled.

[0042] Gas is supplied to the air supply header 123A from a gas supply device (not shown). Also, gas may be supplied to the air supply header 123A from the gas supply unit 161.

[0043] As shown in FIGS. 3 to 5, the front channel 124 is a channel formed on the front side of the housing 120, and communicates with the accommodation space 121 through the housing through-hole 126 and the slit opening 127 (see FIG. 4).

[0044] The side channel 125 is a channel formed on the side surface side of the housing 120, and communicates with the front channel 124 at the tip of the housing 120 (the end on the pinhole member 110 side) (see FIG. 5).

[0045] As shown in FIG. 4, the slit opening 127 is formed on the inner surface on the front side of the inner surface of the housing 120. The slit opening 127 opens in a slit shape elongated in the vertical direction in the figure and passes through the central portion of the inner surface. Note that a housing through-hole 126 is formed in a part of the slit opening 127.

[0046] As shown in FIGS. 4 and 5, the gas supplied from the housing through-hole 126 and the slit opening 127 flows into the front channel 124 so as to spread around the slit opening 127. At this time, since the opening shape is slit-shaped, the flow velocity of the gas flowing from the slit opening 127 into the front channel 124 becomes uniform along the longitudinal direction (the vertical direction in the figure) of the slit opening 127. Note that a part of the gas flows into the pinhole 111 and acts as purge gas.

[0047] As shown in FIG. 5, the gas flowing in the front flow path 124 flows into the side flow path 125, thereby forming a flow path from the front flow path 124 to the side flow path 125. By the gas flowing in this way, the housing 120 is cooled.

[0048] According to the present embodiment, the following effects are achieved. A pinhole member 110 made of a heat insulating material is installed outside the furnace wall 150 in which the furnace wall through hole 151 is formed, and a pinhole 111 is formed so as to see through the inside of the furnace wall 150 through the furnace wall through hole 151. And a photographing unit 140 that photographs the inside of the furnace wall 150 through the furnace wall through hole 151 and the pinhole 111. Therefore, the inside of the furnace can be photographed like a pinhole camera using the photographing unit 140. As a result, the inside of the furnace can be photographed with a simple and inexpensive configuration without using an expensive window material or lens material made of sapphire that transmits infrared rays. At this time, the pinhole member 110 may or may not be in contact with the furnace wall 150, but it may be constructed with contact as a requirement for positioning the pinhole 111. Further, since the pinhole 111 is a micro hole, the thermal influence from the inside of the furnace through the pinhole 111 can be suppressed. Thereby, for example, a camera for normal temperature can be used as the photographing unit 140, and the cost can be reduced. Further, since the pinhole 111 is made of a heat insulating material, it is less likely to be thermally deformed compared to metal. Therefore, it is possible to suppress the pinhole 111, which requires dimensional accuracy, from being thermally deformed.

[0049] In addition, the imaging unit 140 includes a plurality of mirrors 142, 143, 144 and a camera 141. The mirror 142 is disposed at a position where the light entering from the furnace wall through-hole 151 and the pinhole 111 directly hits. The mirrors 143 and 144 are disposed at positions where the light entering from the furnace wall through-hole 151 and the pinhole 111 does not directly hit. The camera 141 is disposed at a position where the light entering from the furnace wall through-hole 151 and the pinhole 111 does not directly hit and behind the mirror 142 in the penetrating direction of the pinhole 111. Since the plurality of mirrors 142, 143, 144 are arranged such that the light entering from the furnace wall through-hole 151 and the pinhole 111 reaches the camera 141, the thermal influence from the furnace interior to the camera 141 can be shielded by the mirror 142 installed in front of the camera 141. Thereby, a camera for normal temperature can be used, and the cost can be reduced.

[0050] In addition, since a housing 120 is provided which contacts the pinhole member 110 outside the furnace wall 150, houses the imaging unit 140, and has an accommodation space 121 formed inside that communicates with the pinhole 111, the imaging unit 140 can be protected inside the housing 120.

[0051] In addition, since a gas supply unit 161 capable of supplying gas to the accommodation space 121 is provided, the gas can be ejected from the pinhole 111 as a purge gas to suppress the phenomenon that the particles in the furnace enter from the pinhole 111. Also, the imaging unit 140 can be cooled by the air flow generated by the gas.

[0052] In addition, the gas supply unit 161 can adjust the pressure of the gas to be supplied, and includes a pressure gauge 162 that measures the pressure in the accommodation space 121, and a control unit that controls the pressure of the gas supplied from the gas supply unit 161 based on the information from the pressure gauge 162. Therefore, the purge amount of the gas (purge gas) ejected from the pinhole 111 can be adjusted by controlling the supplied pressure. That is, the purge amount can be adjusted by controlling the pressure. As a result, the purge amount can be adjusted with higher accuracy than when the flow rate is directly measured to adjust the purge amount. This is because the pinhole 111 is a micro-hole and the amount of gas ejected is very small, making it difficult to directly measure the flow rate to adjust the purge amount.

[0053] In addition, since the housing 120 has an upper flow path 122, a lower flow path 123, a front flow path 124, and a side flow path 125 between the inner surface and the outer surface, the housing 120 can be cooled by supplying gas to each of the flow paths 122, 123, 124, and 125. Thereby, the temperature rise of the imaging unit 140 housed in the housing 120 can be suppressed.

[0054] In addition, since the housing 120 has a slit-shaped slit opening 127 that communicates the accommodation space 121 with the front flow path 124 on the inner surface, the gas supplied into the accommodation space 121 through the slit opening 127 can be supplied to the front flow path 124 and the side flow path 125. Also, by making it slit-shaped, variations in the flow velocity distribution along the longitudinal direction of the slit opening 127 can be suppressed. As a result, the portion of the housing 120 corresponding to the front flow path 124 can be cooled uniformly.

[0055] [Modification Example] In the first embodiment, as shown in FIG. 6, the pinhole member 110 may have a cylindrical portion 114. The cylindrical portion 114 is a cylindrical portion protruding from the front surface 112 of the pinhole member 110 and is integrally formed with the pinhole member 110. The outer shape of the cylindrical portion 114 substantially matches the inner diameter of the furnace wall through-hole 151, and the cylindrical portion 114 fits into the furnace wall through-hole 151. Thereby, the pinhole member 110 can be positioned with respect to the furnace wall 150.

[0056] [Reference Embodiment] In addition to the first embodiment, the inside of the furnace may be monitored by the furnace internal monitoring structure 200 according to the reference embodiment described below.

[0057] Hereinafter, the furnace internal monitoring structure 200 according to the reference embodiment of the present disclosure will be described with reference to FIGS. 7 and 8. Note that the furnace wall 250 has the same configuration as the furnace wall 150 of the first embodiment.

[0058] FIG. 7 is a cross-sectional view of the furnace internal monitoring structure 200 as viewed from the side. FIG. 8 is a longitudinal cross-sectional view showing details of the probe 210.

[0059] As shown in FIGS. 7 and 8, the furnace internal monitoring structure 200 includes a probe 210, a protective cylinder 220, and an imaging unit 240.

[0060] The probe 210 is a metal cylindrical member extending in the axial direction of the axis X. A window portion 211 that opens in a direction perpendicular to the axis X is provided on the tip side of the probe 210 (see FIG. 8). The tip side of the probe 210 including the window portion 211 is inserted into the furnace through the furnace wall through-hole 251. At this time, the opening surface of the window portion 211 is directed toward the position where the burner 260 is installed. In the case of FIG. 8, the opening surface faces upward, but the direction of the opening surface is variable and is not limited to upward.

[0061] A gas supply pipe 212 is provided on the base end side of the probe 210. The gas supply pipe 212 communicates with the inside of the probe 210. The gas supply pipe 212 can be supplied with gas from a gas supply device (not shown), and gas can be supplied into the probe 210 through the gas supply pipe 212. The gas supplied from the gas supply pipe 212 into the probe 210 jets out from the window portion 211 into the furnace. Thereby, cooling of the probe 210 and purging of the window portion 211 can be performed.

[0062] A protective cylinder 220 is provided around the probe 210. The protective cylinder 220 is a member for protecting the probe 210 and the concave mirror 241 etc. disposed inside thereof from the heat in the furnace, and is made of a heat-insulating material. The heat-insulating material may be any material applicable to measurement in a high-temperature environment field, and as an example, alumina fiber can be exemplified. The protective cylinder 220 has an opening at a portion corresponding to the position of the window portion 211 so as not to block the window portion 211.

[0063] The photographing unit 240 includes a concave mirror 241, a lens 242, and a camera 243.

[0064] The concave mirror 241 is disposed inside the probe 210 and at a position where the light entering from the window portion 211 directly hits. The concave mirror 241 is disposed with a predetermined inclination angle so as to be able to reflect the light entering from the window portion 211 toward the lens 242 described later.

[0065] The lens 242 is disposed outside the probe 210 and on the proximal end side of the probe 210. The lens 242 is made of sapphire which easily transmits infrared rays.

[0066] The camera 243 receives the light transmitted through the lens 242 and performs photographing. Information such as images and videos obtained by the camera 243 is displayed on, for example, a monitor monitored by an operator after appropriate processing, and is used as monitoring target information of the furnace internal monitoring system. Thereby, the inside of the furnace can be monitored by the furnace internal monitoring structure 200.

[0067] The first embodiment described as above is understood as follows, for example. A furnace internal monitoring structure (100) according to an aspect of the present disclosure is installed outside a furnace wall (150) in which a through hole (151) is formed, and includes a pinhole member (110) made of a heat-insulating material in which a pinhole (111) for seeing through the inside of the furnace wall is formed through the through hole, and a photographing unit (140) for photographing the inside of the furnace wall through the through hole and the pinhole.

[0068] According to the in-furnace monitoring structure according to this aspect, a pinhole member made of a heat insulating material is installed outside the furnace wall in which a through hole is formed, and a pinhole is formed to look through the inside of the furnace wall through the through hole, and a photographing unit that photographs the inside of the furnace wall through the through hole and the pinhole are provided. Therefore, the inside of the furnace wall can be photographed like a pinhole camera using the photographing unit outside the furnace wall. As a result, the inside of the furnace can be photographed with a simple and inexpensive configuration without using an expensive window material or lens material made of sapphire that transmits infrared rays. In addition, since the pinhole is a micro hole (for example, the inner diameter is about 1 mm to 2 mm), the thermal influence from the inside of the furnace through the pinhole can be suppressed. Thereby, for example, a camera for normal temperature can be used as the photographing unit, and the cost can be reduced. In addition, since the pinhole is made of a heat insulating material, it is less likely to undergo thermal deformation compared to metal. Therefore, it is possible to suppress the pinhole, which requires dimensional accuracy, from undergoing thermal deformation. The heat insulating material is made of a non-metal and is less likely to undergo thermal deformation (thermal elongation, thermal expansion, etc.), and is made of, for example, alumina fiber or ceramic. Here, the inside of the furnace wall is, for example, the inside of the furnace, and more specifically, the inside of the boiler.

[0069] In addition, in the in-furnace monitoring structure according to one aspect of the present disclosure, the photographing unit includes a plurality of mirrors (142, 143, 144) and a camera (141). One mirror (142) is arranged at a position where the light entering from the through hole and the pinhole directly hits, and the other mirrors (143, 144) are arranged at positions where the light entering from the through hole and the pinhole does not directly hit. The camera is arranged at a position where the light entering from the through hole and the pinhole does not directly hit and behind the one mirror in the penetrating direction of the pinhole. The plurality of mirrors are arranged such that the light entering from the through hole and the pinhole reaches the camera.

[0070] According to the in-furnace monitoring structure according to this aspect, the imaging unit includes a plurality of mirrors and a camera. One mirror is disposed at a position where the light entering from the through-hole and the pinhole directly hits, and the other mirrors are disposed at positions where the light entering from the through-hole and the pinhole does not directly hit. The camera is disposed at a position where the light entering from the through-hole and the pinhole does not directly hit and behind one mirror in the penetrating direction of the pinhole. Since the plurality of mirrors are arranged such that the light entering from the through-hole and the pinhole reaches the camera, the thermal influence from the furnace interior to the camera can be shielded by one mirror installed in front of the camera. As a result, a camera for normal temperature can be used, and the cost can be reduced. Here, the plurality of mirrors are, for example, a combination of a concave mirror and a plane mirror. Alternatively, a convex mirror may be employed instead of the concave mirror.

[0071] Further, in the in-furnace monitoring structure according to one aspect of the present disclosure, the pinhole member has a cylindrical portion (114) that fits into the through-hole.

[0072] According to the in-furnace monitoring structure according to this aspect, since it has a cylindrical portion that fits into the through-hole, the pinhole member can be positioned with respect to the furnace wall.

[0073] Further, the in-furnace monitoring structure according to one aspect of the present disclosure includes a housing (120) that contacts the pinhole member outside the furnace wall, forms an accommodation space (121) inside that accommodates the imaging unit and communicates with the pinhole.

[0074] According to the in-furnace monitoring structure according to this aspect, since it includes a housing that contacts the pinhole member outside the furnace wall, forms an accommodation space inside that accommodates the imaging unit and communicates with the pinhole, the imaging unit can be protected inside the housing.

[0075] Further, the in-furnace monitoring structure according to one aspect of the present disclosure includes a gas supply unit (161) capable of supplying gas to the accommodation space.

[0076] According to the in-furnace monitoring structure according to this aspect, since it is provided with a gas supply unit capable of supplying gas to the accommodation space, it is possible to suppress the phenomenon that particles in the furnace enter from the pinhole by ejecting the gas as a purge gas from the pinhole. Further, the imaging unit can be cooled by the air flow generated by the gas. The supplied gas is preferably an inert gas, and examples thereof include air, nitrogen, argon, and the like.

[0077] Further, in the in-furnace monitoring structure according to one aspect of the present disclosure, the gas supply unit is configured such that the pressure of the supplied gas can be adjusted, and the in-furnace monitoring structure includes a pressure measurement unit (162) that measures the pressure of the accommodation space, and a control unit that controls the pressure of the gas supplied from the gas supply unit based on information from the pressure measurement unit (162).

[0078] According to the in-furnace monitoring structure according to this aspect, the gas supply unit is configured such that the pressure of the supplied gas can be adjusted, and includes a pressure measurement unit that measures the pressure of the accommodation space, and a control unit that controls the pressure of the gas supplied from the gas supply unit based on information from the pressure measurement unit. Therefore, the purge amount of the gas (purge gas) ejected from the pinhole can be adjusted by controlling the supplied pressure. That is, the purge amount can be adjusted by controlling the pressure. As a result, the purge amount can be adjusted more accurately than when the flow rate is directly measured to adjust the purge amount. This is because the pinhole is a micro-hole and the amount of gas ejected is very small, so it is difficult to directly measure the flow rate to adjust the purge amount.

[0079] Further, in the in-furnace monitoring structure according to one aspect of the present disclosure, the housing has flow paths (122, 123, 124, 125) between the inner surface and the outer surface.

[0080] According to the in-furnace monitoring structure according to this aspect, since the housing has flow paths between the inner surface and the outer surface, the housing can be cooled by supplying gas to the flow paths. Thereby, an increase in the temperature of the imaging unit housed in the housing can be suppressed.

[0081] In addition, in the furnace internal monitoring structure according to one aspect of the present disclosure, the housing has a slit-shaped slit opening (127) that communicates the accommodation space and the flow path on the inner surface thereof.

[0082] According to the furnace internal monitoring structure of this aspect, since the housing has a slit-shaped slit opening that communicates the accommodation space and the flow path on the inner surface, the gas supplied into the accommodation space can be supplied to the flow path through the slit opening. Further, by making it slit-shaped, variations in the flow velocity distribution along the longitudinal direction of the slit opening can be suppressed. As a result, the housing corresponding to the inner surface where the slit is formed can be cooled uniformly.

[0083] In addition, in the furnace internal monitoring structure according to one aspect of the present disclosure, the pinhole member is installed so as to contact the outside of the furnace wall.

[0084] According to the furnace internal monitoring structure of this aspect, since the pinhole member is installed so as to contact the outside of the furnace wall, the position of the pinhole can be determined by the contact.

[0085] In addition, a boiler according to one aspect of the present disclosure includes the above-described furnace internal monitoring structure and the furnace wall in which a plurality of heat transfer tubes are arranged in a panel shape.

[0086] According to the boiler of this aspect, since it includes the above-described furnace internal monitoring structure and the furnace wall in which a plurality of heat transfer tubes are arranged in a panel shape, the above-described furnace internal monitoring structure can be applied to a boiler in which the furnace wall is a membrane wall.

[0087] In addition, a monitoring system according to one aspect of the present disclosure includes the above-described furnace internal monitoring structure and a processing unit that acquires and processes information from the imaging unit of the furnace internal monitoring structure.

[0088] In addition, an inspection method according to one aspect of the present disclosure includes a step of performing monitoring using the information acquired from the imaging unit of the above-described furnace internal monitoring structure.

Description of Reference Numerals

[0089] 100 Furnace internal monitoring structure 110 Pinhole member 111 Pinhole 112 Front surface 113 Back surface 114 Cylindrical part 120 Housing 121 Accommodation space 122 Upper flow path (flow path) 122A Air supply header 122B Exhaust header 123 Lower flow path (flow path) 123A Air supply header 123B Exhaust header 124 Front flow path (flow path) 125 Side flow path (flow path) 126 Housing through hole 127 Slit opening 140 Photographing part 141 Camera 142 Mirror (one mirror) 143, 144 Mirrors (other mirrors) 150 Furnace wall 151 Furnace wall through hole (through hole) 152 Heat insulating material 161 Gas supply part 162 Pressure gauge (pressure measurement part) 163 Control device 200 Furnace internal monitoring structure 210 Probe 211 Window part 212 Gas supply pipe 220 Protection cylinder 240 Photographing part 241 Concave mirror 242 Lens 243 Camera 250 Furnace wall 251 Furnace wall through hole 260 Burner

Claims

1. A pinhole member made of a non-metallic heat insulating material, which is installed outside a furnace wall in which a through hole is formed, and in which a pinhole for seeing through the inside of the furnace wall is formed through the through hole; An imaging unit that images the inside of the furnace wall through the through hole and the pinhole; A stainless steel housing that contacts the pinhole member outside the furnace wall, houses the imaging unit, and has an accommodation space formed therein that communicates with the pinhole; A gas supply unit capable of supplying gas to the accommodation space; Comprising: The gas supply unit is configured such that the pressure of the supplied gas can be adjusted; A pressure measurement unit that measures the pressure of the accommodation space; A control unit that controls the pressure of the gas supplied from the gas supply unit based on information from the pressure measurement unit; An in-furnace monitoring structure comprising:

2. The imaging unit includes a plurality of mirrors and a camera; One mirror is disposed at a position where the light entering from the through hole and the pinhole directly hits; The other mirrors are disposed at positions where the light entering from the through hole and the pinhole does not directly hit; The camera is disposed at a position where the light entering from the through hole and the pinhole does not directly hit and behind the one mirror in the penetrating direction of the pinhole; The in-furnace monitoring structure according to claim 1, wherein the plurality of mirrors are arranged such that the light entering from the through hole and the pinhole reaches the camera.

3. The in-furnace monitoring structure according to claim 1 or 2, wherein the pinhole member has a cylindrical portion that fits into the through hole.

4. The in-furnace monitoring structure according to any one of claims 1 to 3, wherein the housing has a flow path between an inner surface and an outer surface.

5. The in-furnace monitoring structure according to claim 4, wherein the housing has a slit-shaped slit opening that communicates the accommodation space and the flow path on the inner surface.

6. The in-furnace monitoring structure according to any one of claims 1 to 5, wherein the pinhole member is installed so as to contact the outside of the furnace wall.

7. An in-furnace monitoring structure according to any one of claims 1 to 5; The furnace wall in which a plurality of heat transfer tubes are arranged in a panel shape; A boiler comprising:

8. An in-furnace monitoring structure according to any one of claims 1 to 5; A processing unit that acquires and processes information from the imaging unit of the in-furnace monitoring structure; A monitoring system comprising:

9. An inspection method including a step of performing monitoring using information obtained from the imaging unit of the in-furnace monitoring structure according to any one of claims 1 to 5.

Images