Hole location identification method

Abstract

To provide an improved technique for identifying a location of a hole in piping.SOLUTION: A method of identifying a location of a hole in piping having a fluid flowing therein in one direction is provided, the method involving identifying a location of a hole based on a plurality of vibration measured values at different points spread apart by a given distance along a fluid flow direction in the piping 2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a technique for identifying a perforated location in a pipe from outside the pipe. [Background technology]

[0002] Generally, a technique for identifying holes in a pipe is the method described in Patent Document 1, which detects abnormal sounds of a fluid flowing out of the pipe. The method described in Patent Document 1 detects high-frequency sounds that are generated when a fluid passes through a narrow place such as a hole, and identifies the location of the hole. By identifying the location where the fluid in the pipe flows out to the outside, it is possible to identify sources of danger such as oxygen deficiency.

[0003] However, when the pressure inside the pipe is lower than atmospheric pressure (hereinafter referred to as negative pressure), if a hole occurs, air will enter the pipe from outside, but there is a problem that the abnormal noise generated inside the pipe by the inflow of air is difficult to measure with an abnormal noise detector installed outside the pipe. Negative pressure fluid is generally the exhaust gas from the combustion chamber, and since this exhaust gas is a high-temperature fluid, its heat is often utilized by heat recovery equipment, but the inflow of air causes a drop in the exhaust gas temperature, which reduces the efficiency of the heat recovery equipment, so it is very important to identify and repair the hole.

[0004] Furthermore, as a technique for identifying holes in a negative pressure fluid, there is a neutron moisture meter described in Patent Document 2. This is a technique for identifying holes by measuring the moisture content of a thermal insulation material applied to a high-temperature fluid pipe. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2006-170674 A [Patent Document 2] JP 2007-121026 A Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, the technology described in Patent Document 1 has a problem in that it cannot measure when the inside of the pipe is under negative pressure. In addition, the technology described in Patent Document 2 is a technology for identifying holes in a fluid under negative pressure, but the value changes significantly depending on the humidity of the surrounding environment, and the measurement is based on a relative evaluation by obtaining measurements at multiple normal points without holes, so it is difficult to identify the location of the hole. As such, there is room for improvement in the technology for identifying the location of a hole in a pipe from outside the pipe.

[0007] In view of the above circumstances, an object of the present disclosure is to improve the technology for identifying perforated locations in piping. [Means for solving the problem]

[0008] (1) A method for identifying a perforated portion according to an embodiment of the present disclosure includes: A method for identifying a hole in a pipe through which a fluid flows in one direction, comprising: The method is characterized in that the location of the hole is identified based on a plurality of vibration measurement values ​​at different positions in the piping, the positions being spaced at predetermined intervals along the flow direction of the fluid.

[0009] (2) A method for identifying a perforated portion according to an embodiment of the present disclosure is the method for identifying a perforated portion according to (1), comprising: The plurality of vibration measurement values ​​are obtained by a plurality of vibration detection devices attached to the piping at different positions at predetermined intervals along the flow direction of the fluid.

[0010] (3) A method for identifying a perforated portion according to an embodiment of the present disclosure is a method according to (1) or (2), The method is characterized in that the flow rate of fluid flowing in or out of the perforated location is determined based on the multiple vibration measurement values. Effect of the Invention

[0011] According to one embodiment of the present disclosure, the technology for identifying perforated locations in piping can be improved. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a factory layout. [Diagram 2] FIG. 13 is a diagram showing an example in which a hole is provided in a pipe. [Diagram 3] FIG. 13 is a diagram showing another example in which holes are provided in a pipe. [Figure 4] FIG. 13 is a diagram showing another example in which holes are provided in a pipe. [Diagram 5] 11 is a graph showing the relationship between the hole diameter and the vibration measurement values ​​obtained by the first AE sensor and the fourth AE sensor. [Figure 6] 11 is a graph showing the relationship between the distance to a hole and vibration measurement values ​​obtained by a first AE sensor, a second AE sensor, and a third AE sensor. [Figure 7] 1 is a graph showing the relationship between vibration measurement values ​​and Q / L. [Figure 8] This is a factory layout diagram showing ducts and other structures with thermal insulation. [Figure 9] 13 is an example of a risk level display. [Figure 10] 1 is a diagram illustrating an example of a configuration of an information processing device that presents a risk level display. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The inventors have considered that, in a method for identifying a perforated portion, it is possible to detect both the case where a fluid (gas) flows out of the perforated portion and the case where a fluid flows in from the perforated portion by detecting the vibration of the perforated portion when a fluid passes through the perforated portion, rather than detecting the abnormal sound itself as in the conventional documents. As a result of intensive research, the inventors have found that the accuracy of identifying the position of a perforated portion can be improved by using, for example, an AE (Acoustic Emission) sensor (hereinafter also referred to as an AE sensor) as a sensor for detecting high-frequency vibration. Note that the present invention is intended for use in exhaust gas piping, but can also be applied to gas piping, air piping, and any other fluid piping. In addition, although the present invention uses an AE sensor as a sensor for measuring high-frequency vibration, any other vibration detection device capable of acquiring vibration of a high frequency can be used. Hereinafter, a technique for identifying a perforated portion according to an embodiment of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding parts are assigned the same reference numerals. In the description of this embodiment, the description of the same or corresponding parts will be omitted or simplified as appropriate.

[0014] Fig. 1 shows a layout diagram of a factory to which a method for identifying a perforated portion according to an embodiment of the present disclosure is applied. As shown in Fig. 1, in this embodiment, exhaust gas discharged from a furnace 5 filling a pipe 2 (hereinafter also referred to as a duct 2) is exhausted by an exhaust fan 1. In other words, in the pipe 2, the exhaust gas, which is a fluid, flows in one direction from the furnace 5 toward the exhaust fan 1.

[0015] Here, the air pressure inside the duct 2 is lower than atmospheric pressure (negative pressure) because exhaust gas is being exhausted by the exhaust fan 1. The duct 2 is connected with a flange 11 so that the inside of the duct 2 can be inspected.

[0016] A first vibration detection device 4a, a second vibration detection device 4b, a third vibration detection device 4c, and a fourth vibration detection device 4d are attached to the piping 2 as sensors for detecting high-frequency vibrations. Hereinafter, the first vibration detection device 4a, the second vibration detection device 4b, the third vibration detection device 4c, and the fourth vibration detection device 4d are also referred to as the AE sensor 4a, the AE sensor 4b, the AE sensor 4c, and the AE sensor 4d, respectively. The AE sensors 4a, 4b, 4c, and 4d are attached at different positions at equal intervals from each other at a predetermined interval (distance D described below).

[0017] In this facility, holes were drilled between the AE sensors 4a as shown in Figures 2 to 4, and a method for measuring the locations of the holes was verified using vibration measurements (here, measurements of the AE sensors, hereinafter also referred to as AE values). The first hole 3a shown in Figure 2 is provided at a position 1 / 3D from the AE sensor 4a, where D is the distance between the AE sensors 4a and 4d. The second hole 3b shown in Figure 3 is provided at a position 1 / 2D from the AE sensor 4a. The third hole 3c shown in Figure 4 is provided at a position 2 / 3D from the AE sensor 4a.

[0018] The measurement results of the AE value obtained for each of the first hole 3a, the second hole 3b, and the third hole 3c are as follows. Here, the hole diameter of the first hole 3a, the second hole 3b, and the third hole 3c was each set to Φ7 mm.

[0019] [Table 1]

[0020] As shown in the results of the AE values ​​for the first hole 3a and the AE values ​​for the first hole 3a in Table 1, the closer the measurement position of the AE sensor is to the hole, the larger the AE value is. Specifically, for the AE value for the first hole 3a, the AE value of the AE sensor 4a closer to the first hole 3a is larger than the AE value of the AE sensor 4d. On the other hand, for the AE value for the third hole 3c, the AE value of the AE sensor 4d closer to the third hole 3c is larger than the AE value of the AE sensor 4a.

[0021] Furthermore, as shown by the results of the AE value related to the second hole 3b, when the holes and the sensor positions were equidistant, the AE sensor 4a and the AE sensor 4d showed the same AE value.

[0022] From the above results, the inventors obtained the following equation (1) as the relation between the hole position and the AE value. L=D×AE2 / (AE1+AE2)·······(1) Here, L represents the distance between the hole and the position where the first reference sensor (here, AE sensor 4a) is provided, AE1 represents the AE value measured by the first reference sensor, and AE2 represents the AE value measured by the second reference sensor (here, AE sensor 4d).

[0023] The above method makes it possible to identify the location of a hole with high accuracy regardless of whether the hole is the first hole 3a, the second hole 3b, or the third hole 3c. That is, the location of a hole can be identified based on a plurality of vibration measurement values ​​at different positions at a predetermined interval in the flow direction of the fluid in the pipe 2.

[0024] If there are multiple holes in the pipe 2, the AE sensor 4a and the AE sensor 4d will each measure the AE value of a nearby hole. In this case, the multiple holes can be considered as one large hole (hereinafter also referred to as a virtual hole) and the above formula (1) can be applied. In this case, the location of the virtual hole can be identified by formula (1). In actual operation, the multiple holes corresponding to the virtual hole can be identified by visually inspecting the surroundings of the virtual hole.

[0025] In the example shown in FIG. 2 to FIG. 4, the first hole 3a, the second hole 3b, and the third hole 3c are provided between the AE sensor 4a and the AE sensor 4d. However, there may be a case where the holes are provided outside the AE sensor 4a and the AE sensor 4d. Therefore, it is preferable to install two or more AE sensors at equal intervals. That is, as shown in FIG. 1, in addition to the AE sensor 4a and the AE sensor 4d, it is preferable to install the AE sensor 4b, the AE sensor 4c, etc. at different positions at equal intervals (distance D) from each other. In this case, it is sufficient to apply the formula (1) assuming that there is a hole between two sensors having a large AE value among the multiple AE sensors. In this case, the above-mentioned first reference sensor is the AE sensor having the largest AE value among the multiple AE sensors. Also, the second reference sensor is the AE sensor having the second largest AE value among the multiple AE sensors. When there are two AE sensors showing the largest AE value, one of the AE sensors may be the first reference sensor. In this case, the other AE sensor is the second reference sensor.

[0026] As described above, the method for identifying a perforated portion according to the embodiment of the present disclosure makes it possible to identify a perforated portion with high accuracy. Here, for example, when holes occur in multiple locations in the pipe 2, it is preferable to be able to determine which hole should be given priority for repair or other measures. Specifically, it is preferable to be able to identify how much fluid is flowing in or out of the hole in the pipe 2, that is, the fluid flow rate. Therefore, the inventors further studied a method for calculating the fluid flow rate from the AE value.

[0027] Here, the fluid flow rate was examined when the hole diameter of the second hole 3b was changed. Figure 5 shows the results of the AE values ​​measured by the AE sensor 4a and the AE sensor 4d. The AE sensor 4a is installed near the second hole 3b. The AE sensor 4d is installed on the flange 11 surface. In this examination, the hole diameter of the hole 3b was changed in the range of Φ1 to Φ7 mm. In Figure 4, the horizontal axis is the hole diameter, and the vertical axis is the AE value. Here, the AE sensor 4a and the AE sensor 4d are positioned at the same distance from the second hole 3b.

[0028] Vibrations caused by the outflow of fluid from second hole 3b are propagated to the surface and flange face of pipe 2 and are output as an AE value. It can also be seen that the AE value changes according to the hole diameter, and the AE value increases as the hole diameter becomes larger and the amount of air flowing in increases. In Figure 5, the white circles indicate the AE values ​​measured by AE sensor 4a, and the black circles indicate the AE values ​​measured by AE sensor 4d. Comparing the plots of the white circles with the plots of the black circles, it can be seen that the same tendency occurs regardless of whether the AE sensor is installed on the surface or flange face of pipe 2.

[0029] Figure 6 shows the AE value results obtained by AE sensor 4a, AE sensor 4b, and AE sensor 4c when the hole diameter of second hole 3b was Φ7 mm. In Figure 6, the distance on the horizontal axis is the distance between each AE sensor and the hole, and the vertical axis is the AE value measured by each AE sensor. As shown in Figure 6, it can be seen that the AE value decreases as the distance from second hole 3b increases. Furthermore, Figures 5 and 6 show that the AE value changes depending on the amount of air inflow, which varies depending on the hole diameter, and the distance.

[0030] The inventors measured the flow rate Q of the water flowing into the hole and found a correlation between Q / L and the AE value. Specifically, as shown in Figure 7, they found a quadratic correlation between Q / L and the AE value, and obtained the relational expression shown in formula (2). Q / L = aAE 2 + b AE + c (2) Here, Q is the flow rate of the fluid flowing in from the hole, and L is the distance between the hole and the AE sensor. a, b, and c are coefficients. Since the coefficients a, b, and c vary depending on the material of pipe 2, the temperature of the fluid, the type of fluid (gas composition), etc., they can be calculated based on multiple data for each pipe and each fluid.

[0031] The value of L in formula (2) can be calculated using formula (1). In the example shown in Fig. 7, the second hole 3b is the subject of the calculation, so in order to calculate the flow rate of the second hole 3b, 1 / 2D is substituted for the value of L in formula (2). This makes it possible to obtain a formula for calculating the flow rate of the water flowing into the second hole 3b (the following formula (3)). Q = D (a AE 2 + b A E + c) / 2 (3)

[0032] Fig. 8 shows equipment equivalent to that shown in Fig. 1 to which a heat insulating material 9 has been applied. As shown in Fig. 8, in this embodiment, exhaust gas discharged from a furnace 12 filling a pipe 7 (hereinafter also referred to as a duct 7) is exhausted by an exhaust fan 6. The pressure inside the duct 7 is lower than atmospheric pressure due to exhaust by the exhaust fan 6. A hole 8 with a hole diameter of Φ1 to Φ7 mm was opened in the duct 7, and AE sensors 10a and 10c were installed above the heat insulating material, and AE sensor 10b was installed in a location without heat insulating material. When a verification similar to that of the configuration of Fig. 1 without heat insulating material was performed, the same trends as those of Figs. 5 to 7 described above were obtained.

[0033] In this way, the method for identifying a perforated location according to an embodiment of the present disclosure can identify a perforated location and obtain its flow rate by using the vibration measurement position (here, the installation position of the AE sensor) and formula (1) and formula (2). Therefore, the priority of repairing a perforated location by displaying the danger level can be determined according to the size of the hole, the rank of important equipment, etc., and the repair timing can be optimized.

[0034] FIG. 9 is an example of the above-mentioned risk display. The risk display can be performed by a display unit or the like of an information processing device such as a tablet terminal. In FIG. 9, an object 90 corresponding to the identified perforated location and flow rate is displayed in the image of the duct by using the vibration measurement position (here, the installation position of the AE sensor) and the formula (1) and the formula (2) according to the identified perforated location and flow rate. The image of the duct may be an image captured in advance, or may be a real-time image captured by the information processing device, that is, an AR (Augmented Reality) image. For example, when the imaging unit of the information processing device such as a tablet terminal is directed toward the target duct, an AR image may be displayed in real time. Note that the information processing device may perform the process of identifying the perforated location and the flow rate based on the formula (1) and the formula (2) using the vibration measurement position and the vibration measurement value.

[0035] 10 is an example of a hardware configuration of an information processing device 100 according to an embodiment of the present disclosure. As shown in FIG. 10, the information processing device 100 includes a control unit 101, a storage unit 102, a communication unit 103, an input unit 104, and a display unit 105.

[0036] The control unit 101 includes at least one processor, at least one dedicated circuit, or a combination of these. The processor is a general-purpose processor such as a central processing unit (CPU) or a graphics processing unit (GPU), or a dedicated processor specialized for a specific process. The dedicated circuit is, for example, a field-programmable gate array (FPGA) or an application specific integrated circuit (ASIC). The control unit 101 executes processes related to the operation of the information processing device 100 while controlling each unit of the information processing device 100.

[0037] The storage unit 102 includes at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or a combination of at least two of these. The semiconductor memory is, for example, a random access memory (RAM) or a read only memory (ROM). The RAM is, for example, a static random access memory (SRAM) or a dynamic random access memory (DRAM). The ROM is, for example, an electrically erasable programmable read only memory (EEPROM). The storage unit 102 functions as, for example, a main storage device, an auxiliary storage device, or a cache memory. The storage unit 102 stores data used in the operation of the information processing device 100 and data obtained by the operation of the information processing device 100.

[0038] The communication unit 103 includes at least two wireless communication interfaces. Specifically, the wireless communication interfaces include an interface corresponding to communication via the first dedicated network and an interface corresponding to communication via the second dedicated network. The communication unit 103 receives data used in the operation of the information processing device 100, and transmits data obtained by the operation of the information processing device 100.

[0039] The input unit 104 includes at least one input interface. The input interface is, for example, a physical key, a capacitive key, a pointing device, or a touch screen integrally provided with a display. The input interface may also be, for example, a microphone that accepts voice input, or a camera that accepts gesture input. The input unit 104 accepts an operation to input data used for the operation of the information processing device 100. The input unit 104 may be connected to the information processing device 100 as an external input device instead of being provided in the information processing device 100. As a connection method, any method such as USB (Universal Serial Bus), HDMI (registered trademark) (High-Definition Multimedia Interface), or Bluetooth (registered trademark) can be used.

[0040] The display unit 105 includes at least one display output interface. The display output interface is, for example, a display that outputs information as a video. The display is, for example, a liquid crystal display (LCD) or an organic EL (electro luminescence) display. The display unit 105 displays and outputs data obtained by the operation of the information processing device 100. The display unit 105 may be connected to the information processing device 100 as an external output device instead of being provided in the information processing device 100. As a connection method, any method such as USB, HDMI (registered trademark), or Bluetooth (registered trademark) can be used.

[0041] The functions of the information processing device 100 are realized by executing a program according to this embodiment on a processor equivalent to the information processing device 100. That is, the functions of the information processing device 100 are realized by software. The program causes a computer to execute the operations of the information processing device 100, thereby causing the computer to function as the information processing device 100. That is, the computer functions as the information processing device 100 by executing the operations of the information processing device 100 in accordance with the program.

[0042] In this embodiment, the computer temporarily stores, for example, a program recorded on a portable recording medium or a program transmitted from a server in a main storage device. Then, the computer reads the program stored in the main storage device with a processor, and executes processing according to the read program with the processor. The computer may read the program directly from the portable recording medium and execute processing according to the program. The computer may execute processing according to the received program each time it receives a program from an external server. The external server may not transmit a program to the computer, but may execute processing by a so-called ASP (application service provider) type service that realizes functions only by execution instructions and result acquisition. Programs include information used for processing by an electronic computer that is equivalent to a program. For example, data that is not a direct instruction to a computer but has a nature that specifies computer processing corresponds to "something equivalent to a program."

[0043] In this embodiment, the program can be recorded on a computer-readable recording medium. The computer-readable recording medium includes a non-transitory computer-readable medium, such as a magnetic recording device, an optical disc, a magneto-optical recording medium, or a semiconductor memory. The program is distributed, for example, by selling, transferring, or lending a portable recording medium such as a DVD (digital versatile disc) or a CD-ROM (compact disc read only memory) on which the program is recorded. The program may also be distributed by storing the program in the storage of an external server and transmitting the program from the external server to another computer. The program may also be provided as a program product.

[0044] A part or all of the functions of the information processing device 100 may be realized by a dedicated circuit equivalent to the control unit 101. In other words, a part or all of the functions of the information processing device 100 may be realized by hardware.

[0045] (Example) The results of applying the above-mentioned position identification method and fluid flow rate identification method are shown below. Table 2 shows the results when one hole is provided between the AE sensor 4a and the AE sensor 4d shown in FIG. 1, and Table 3 shows the results when one hole is provided between the AE sensor 4a and the AE sensor 4d and between the AE sensor 4a and the AE sensor 4b shown in FIG. 1. Here, in Table 3, the space between the AE sensor 4a and the AE sensor 4d is designated as "hole 1," and the space between the AE sensor 4a and the AE sensor 4b is designated as "hole 2." Here, the position of the hole indicates the distance from the AE sensor 4a, and with reference to FIG. 1, the right side of the AE sensor 4a on the paper is designated as a positive value, and the left side of the paper is designated as a negative value.

[0046] In either case, the error between the actual and calculated positions of the perforated area was within 50 mm, which shows that the perforated area was accurately identified. In addition, the difference between the actual measured and calculated values ​​of the fluid flow rate was within 2 m. 3 This shows that the accuracy is within / h, and the identification is highly accurate.

[0047] [Table 2]

[0048] [Table 3]

[0049] In the present embodiment, an example has been shown in which a plurality of vibration measurement values ​​such as AE values ​​are respectively acquired by a plurality of AE sensors attached at different positions at a predetermined interval along the flow direction of the fluid in the pipe 2, but this is not limiting. For example, a plurality of vibration measurement values ​​may be acquired by a single vibration measuring device. In this case, by moving the single vibration measuring device along the pipe 2, a plurality of vibration measurement values ​​at different positions at a predetermined interval along the flow direction of the fluid can be acquired.

[0050] In this embodiment, the pressure inside the pipe is negative, but this is not limited to this. Even if the pressure inside the pipe is positive (higher than atmospheric pressure), the method for identifying a perforated portion according to the present disclosure can be applied.

[0051] Although the present disclosure has been described based on the drawings and embodiments, it should be noted that those skilled in the art can easily make various modifications and corrections based on the present disclosure. Therefore, it should be noted that these modifications and corrections are included in the scope of the present disclosure. For example, the functions included in each means or step can be rearranged so as not to be logically inconsistent, and multiple means or steps can be combined or divided into one. [Explanation of symbols]

[0052] 1 Exhaust fan 2. Ducts 3a, 3b, 3c holes 4a First vibration detection device (AE sensor) 4b Second vibration detection device (AE sensor) 4c Third vibration detection device (AE sensor) 4d Fourth vibration detection device (AE sensor) 5 Furnace 11 Flange 6 Exhaust Fan 7 Piping (Duct) 8 holes 9. Insulation 10a AE sensor 10b AE sensor 10c AE sensor 100 Information processing device 101 Control section 102 Storage section 103 Communications Department 104 Input section 105 Display section

Claims

1. A method for identifying a hole in a pipe through which a fluid flows in one direction, comprising: A method for identifying a perforated location, comprising: identifying the perforated location in the piping based on a plurality of vibration measurement values ​​at different positions spaced at predetermined intervals along the flow direction of the fluid.

2. The method for identifying a perforated portion according to claim 1, A method for identifying perforated locations, characterized in that the multiple vibration measurement values ​​are respectively obtained by multiple vibration detection devices mounted at different positions in the piping, spaced a predetermined distance apart along the flow direction of the fluid.

3. The method for identifying a perforated portion according to claim 1 or 2, A method for identifying a perforated location, comprising determining a flow rate of fluid flowing in or out of the perforated location based on the plurality of vibration measurement values.

Images