KR102353866B1 - Displacement and rotation measuring device for high temperature and strain measuring device for high temperature based on IoT and system for evaluating safety of piping using thereof - Google Patents

Abstract

The present invention relates to a device and a method for evaluating the safety of a pipe, and more specifically, to an IoT-based high-temperature displacement and rotation measurement device, a high-temperature strain rate measurement device, and a pipe safety evaluation system using the same. According to the present invention, in a conventional case, there has been a limitation in that for a pipe applied to the high-temperature environment, a measurement device and a measurement method which are capable of measuring a part-specific displacement of the pipe, caused by thermal deformation of the pipe or subsidence or deformation of the ground or a support device, finding a fragile site, performing maintenance and repairing, and preventing damage to the pipe in advance have not been presented. In order to solve the problems of the conventional measurement device and measurement method for a pipe, displacement sensors for measuring a displacement and rotation and strain sensors for measuring a strain rate are installed at regular intervals on each part of a pipe so as to monitor the occurrence of a displacement caused by thermal deformation due to heat or subsidence of the ground or a support device due to a load, evaluate the safety of the pipe based on the respective measurement values, and determine whether to perform maintenance and repairing according to the evaluation results. Accordingly, the present invention is capable of effectively preventing damages to the pipe and securing the safety of the entire facility.

Description

Displacement and rotation measuring device for high temperature and strain measuring device for high temperature based on IoT and system for evaluating safety of piping using thereof }

The present invention relates to an apparatus and method for evaluating the safety of piping, and more specifically, for example, a high-temperature plant piping applied to a high-temperature, high-pressure environment, such as a thermal power plant, causes thermal deformation due to heat. In addition, the displacement of the pipe occurs due to subsidence or deformation of the ground or support device due to the load of the pipe itself, and if this deformation or displacement is severe, the pipe is damaged and there is a risk that it may lead to a major accident. In order to solve the problem of high-temperature plant piping in It relates to an IoT-based displacement and rotation measuring device for high temperature and strain measuring device for high temperature, which are configured to ensure safety, and a piping safety evaluation system using the same.

In addition, the present invention monitors the overall condition of the pipe as described above to find a vulnerable part where abnormal deformation or abnormal displacement and torsion occurs, and to ensure the safety of the pipe by performing maintenance in advance, A sensor unit for detecting displacement and rotation and an MCU for control are disposed inside and outside each integrally with the insulating material surrounding the pipe, and a displacement sensor consisting of a distributed sensor that transmits and receives various data based on IoT, and measures the strain For IoT-based high temperature, which includes a strain sensor consisting of a sensor unit for controlling Displacement and rotation measuring device, high temperature strain measuring device, and piping safety evaluation system using the same.

In addition, the present invention, as described above, by measuring the displacement due to thermal deformation of the pipe or subsidence or deformation of the ground or support device for each part as described above to find the weak spot and perform maintenance to prevent damage to the pipe in advance. In order to solve the problems of the pipe measuring devices and methods of the prior art, which had limitations in which the measuring devices and methods were not presented, the displacement sensors and strains for measuring displacement and rotation at regular intervals for each part of the pipe were measured. Each strain sensor is installed to monitor displacement caused by thermal deformation due to heat or subsidence of the ground or support device due to load, and whether or not maintenance is performed according to the evaluation result by evaluating the safety of the pipe based on each measured value It relates to an IoT-based high-temperature displacement and rotation measuring device and high-temperature strain measuring device, and a pipe safety evaluation system using the same, which are configured to effectively prevent pipe breakage and secure the safety of the entire facility by determining

In general, high-temperature pressure piping installed in facilities such as thermal power plants undergoes thermal deformation while periodically repeating hot and cold states, for example, thermal expansion exceeding the design value, failure of the pipe support device, failure due to load, or ground Abnormal displacement of the pipe may occur due to problems of the pipe support device supporting the pipe, such as subsidence, and such thermal deformation or abnormal displacement may cause damage to the pipe and lead to a major accident.

In addition, pipes exposed to high temperature environments for a long time have a risk of creep damage, and excessive displacement compared to the initial design may cause additional damage. We are performing over-hole, predicting the stress in the pipe through various numerical analysis techniques, and performing maintenance based on this.

Here, as an example of the prior art for an apparatus and method for measuring the condition of a pipe and determining whether there is a risk in order to prevent damage to the pipe as described above, for example, in Korea Patent Publication No. 10-1104891 As suggested, there is a "method of selecting an inspection site during pipe operation using risk information".

More specifically, the above-mentioned Korean Patent Publication No. 10-1104891 uses a probabilistic safety evaluation model to qualitatively evaluate the accidental end in case of a related pipe breakage, and to segment it in consideration of the pipe material and system characteristics. Step 1; a second step of qualitatively evaluating by using a probabilistic safety evaluation model that recognizes a pipe that is likely to cause an initial event and loss of system function under the condition of pipe damage; A third step of selecting a device that can cause the same damage as in the case of pipe breakage as a replacement device, and quantifying the risk due to pipe damage using the probabilistic safety evaluation model of the replacement device to obtain a conditional risk of pipe damage; A fourth step of obtaining the probability of pipe failure by using a probabilistic fracture mechanics code for the pipe in which the occurrence of an initial event and loss of system function are expected when the pipe is damaged; After multiplying the pipe break conditional risk and the pipe breakage probability, the risk for each pipe section is calculated as a Core Damage Frequency (CDF) value, and the risk of each pipe section is summed to calculate the overall risk of the pipe. a fifth step of calculating the ratio of the risk to the overall risk of the pipe and calculating the risk importance for each pipe as an RRW (Risk Reduction Worth) value; a sixth step of determining a pipe having an RRW value of 1005 or more as an inspection target pipe; and the seventh step of selecting an inspection site within the inspection target pipe, by evaluating the risk on the safety of the power plant for each part of the pipe within the analysis range and performing a customized non-destructive inspection accordingly to reduce the quantity of inspection by about 50% or more It relates to a method for selecting an inspection site during pipe operation using risk information that is configured to perform intensive inspection on important parts at low cost.

As described above, in the prior art, various technical contents for measuring the state of the pipe and preventing damage have been presented, but the contents of the prior art as described above have the following problems.

More specifically, as described above, in order to secure the soundness of the high-temperature pressure pipe, it is necessary to first identify the vulnerable part and perform maintenance on the corresponding part. It is possible to find a high-stress area and select it as a vulnerable area, and to evaluate the creep and fatigue life by calculating the exact local stress on the vulnerable area.

Here, the accuracy of numerical analysis for predicting actual piping behavior is important in the safety of high-temperature pressure piping, but it is difficult to accurately calculate local stress based on limited field piping information.

That is, in the case of a piping system in operation for a long period of time, it is necessary to consider both the initial design state and the changed restraint support conditions due to the renovation of the piping and the expansion of the piping support device. There is a problem in that it is difficult to accurately simulate the behavior of an actual high-temperature pressure pipe because it is performed for the entire piping system or between the restraining points based on the dimensions.

In addition, since the existing numerical analysis methods target the entire piping line based on the beam element, there is a disadvantage in that it is difficult to predict the local stress at the dangerous point.

More specifically, in the case of a critical pipe of a coal-fired power plant that continues to operate after ignition according to a starting method, creep occurs because it is continuously exposed to a high-temperature and high-pressure environment, and DSS (Daily Start Stop) and WSS (Daily Start Stop) The critical piping of the combined cycle power plant that frequently starts the Weekly Start Stop method has a risk of fatigue damage.

In addition, in order to accurately evaluate the life of creep and fatigue failure, it is necessary to calculate the local maximum stress and strain occurring in the piping at the evaluation location. However, in the contents of the prior art as described above, as described above, by measuring displacement and deformation over the entire pipe, the technical content for finding a weak point in a specific location and performing maintenance is presented. there was no

Therefore, in order to solve the problems of the prior art as described above, the displacement and torsion (rotation) of the pipe for the current operating and non-operating state are accurately measured, respectively, with a relatively simple configuration and low cost, and the measured information is used to It is desirable to present a piping safety evaluation system of a new configuration that is configured to effectively prevent pipe damage and accidents in advance by evaluating the safety of the piping through numerical analysis and performing maintenance. There is no device or method that satisfies all of the requirements.

Korean Patent Publication No. 10-1104891 (2012.01.04.)

The present invention is to solve the problems of the prior art as described above, and therefore, an object of the present invention is, for example, a high-temperature plant pipe applied to a high-temperature, high-pressure environment such as a thermal power plant, and There is a risk of damage due to displacement due to subsidence or deformation of the ground or support device due to load. In order to solve the problems of the pipe measuring device and method of the prior art, which were not presented, by monitoring the overall condition of the pipe, finding the vulnerable part where abnormal deformation or abnormal displacement and torsion occurred, and maintaining the found vulnerable part in advance This is to present an IoT-based high-temperature displacement and rotation measurement device and high-temperature strain measurement device and a piping safety evaluation system using the same, which are configured to ensure the safety of piping by performing

In addition, another object of the present invention is to monitor the overall condition of the pipe as described above to find a vulnerable part where abnormal deformation or abnormal displacement and torsion occurred, and to secure the safety of the pipe by performing maintenance in advance. In order to do this, a sensor unit for detecting displacement and rotation and an MCU for control are disposed inside and outside each integrally with the insulating material surrounding the pipe, and a displacement sensor consisting of a distributed sensor that transmits and receives various data based on IoT; IoT consisting of a strain sensor consisting of a sensor unit for measuring strain and a distributed sensor that transmits/receives various data based on IoT, where the MCU for control is placed inside and outside in one piece with the insulation surrounding the pipe This is to present a displacement and rotation measuring device for high temperature base, a strain measuring device for high temperature and a piping safety evaluation system using the same.

In addition, another object of the present invention, as described above, by measuring the displacement due to the thermal deformation of the pipe or subsidence or deformation of the ground or support device for each part as described above to find the weak part and perform maintenance to prevent the damage of the pipe in advance Displacement sensor for measuring displacement and rotation at regular intervals for each part of the pipe in order to solve the problems of the pipe measuring device and method of the prior art, which had a limitation that a measuring device and method for preventing By installing strain sensors to measure the strain and strain, respectively, the occurrence of displacement due to thermal deformation due to heat or subsidence of the ground or support device due to load is monitored. IoT-based high-temperature displacement and rotation measuring device and high-temperature strain measuring device and piping safety evaluation system that are configured to effectively prevent pipe damage and secure the safety of the entire facility by deciding whether to maintain or not that you want to present.

In order to achieve the above object, according to the present invention, in the pipe safety evaluation system, a displacement measuring unit for measuring the displacement and rotation (torsion) of the pipe; Strain measuring unit for measuring the strain (strain) of the pipe; a communication unit for transmitting and receiving various data including measurement values with another evaluation system or an external device through at least one of wired or wireless communication; and controlling the operation of the displacement measuring unit, the strain measuring unit, and the communication unit, respectively, evaluating the safety of the pipe based on the measurement values measured by the respective measuring sensors of the displacement measuring unit and the strain measuring unit, and whether to perform maintenance and a control unit configured to perform a process of sending a notification or warning to a person in charge or a related organization according to a predetermined setting when maintenance is required or an accident or danger including pipe breakage occurs A piping safety evaluation system is provided.

Here, the displacement measuring unit is characterized in that it is configured to include a plurality of displacement sensors installed in the pipe at a predetermined position or a predetermined interval.

In addition, the displacement sensor is composed of a 6 degree of freedom (DOF) sensor using an accelerometer and a gyro sensor to detect displacement and rotation (torsion) of the pipe, respectively, and A sensor unit for measurement is installed inside, and a microcontroller unit (MCU) for control is respectively disposed outside the insulation to transmit and receive measurement values and various data based on the Internet of Things (IoT). It is characterized in that it is composed of

In addition, the strain measuring unit is characterized in that it is configured to include a plurality of strain sensors installed in the pipe at a predetermined position or at a predetermined interval.

Furthermore, the strain sensor is composed of a fiber bragg grating (FBG) sensor for measuring strain of the pipe, and a sensor unit for measurement is installed inside the insulating material surrounding the outside of the pipe, and the outside of the insulating material Each microcontroller unit (MCU) for control is arranged in the Internet of Things (IoT)-based, characterized in that it is composed of a distributed sensor configured to transmit and receive measurement values and various data.

In addition, the control unit receives the measured values measured in real time through the displacement measuring unit and the strain measuring unit and storing them in a separate storage means, and based on digital twin technology, each of the measured values is Based on the finite element analysis (FEA), the current state of the entire pipe and the occurrence of abnormal displacement or abnormal deformation are monitored. It is characterized in that it is characterized in that it is determined that an abnormal occurrence or maintenance is required, and a process of delivering the corresponding fact to a designated contact according to a predetermined setting to respond is automatically performed.

In addition, the control unit receives the measurement values transmitted from the respective sensors of the displacement measurement unit and the strain measurement unit, respectively, and stores them in a separate storage means in the form of a database, and based on the received measurement values, the The local stress is calculated through finite element analysis (FEA) for the displacement value of the pipe and a stress analysis is performed. Based on the result of the stress analysis for the displacement value of the pipe and the received measured values, the rotation value of the pipe Calculating the local stress through finite element analysis (FEA) and performing stress analysis for Stress analysis is performed and verified by comparing it with the stress analysis results for the displacement and rotation values of the pipe. It is characterized in that the result is output through a separate display means, and when it is determined that there is an abnormality, a process of delivering a notification of the corresponding fact to the designated contact according to preset contents is performed.

Furthermore, the control unit collects each measurement value and analysis result, and establishes a database for the monitoring result of the pipe by correlating the state of the pipe according to each measured value and storing it in a database form, and deep learning (Deep Learning) Learning) or machine learning (Machine Learning) using an artificial intelligence learning algorithm to learn the contents of the database, and through regression analysis using the learning result and artificial neural network (ANN) It is characterized in that the process for evaluating the analysis and safety is configured to be performed automatically.

In addition, according to the present invention, in the pipe safety evaluation method using the pipe safety evaluation system described above, the measured value transmitted from each displacement sensor and strain sensor installed in the pipe through the control unit of the pipe safety evaluation system a data collection step in which each receiving and storing in a separate storage means in the form of a database is performed; a displacement analysis step in which, through the control unit, a process of calculating a local stress according to the displacement of the pipe through finite element analysis (FEA) based on the displacement value of the pipe received in the data collection step and performing a stress analysis is performed; Through the control unit, on the basis of the analysis result of the displacement analysis step and the rotation value of the pipe received in the data collection step, the local stress according to rotation (torsion) is calculated through FEA, and the stress analysis is performed. a rotation analysis step in which processing is performed; Through the control unit, based on the strain value of the pipe received in the data collection step, local stress according to strain is calculated through FEA through finite element analysis (FEA) and stress analysis is performed to analyze the displacement analysis step and the rotation analysis step a verification step in which a verification process by comparison with a result is performed; a safety evaluation step in which, through the control unit, a process of determining whether there is an abnormality in the pipe and whether maintenance is required is performed according to a predetermined standard based on each analysis result; And, through the control unit, the evaluation result of the safety evaluation step is output through a separate display means, and when it is determined that there is an abnormality, a process of delivering a notification about the fact to a predetermined contact information according to preset contents is performed There is provided a piping safety evaluation method, characterized in that the processing including the notification step is configured to be performed.

Here, in the method, through the control unit, each measurement value and analysis result are collected and the state of the pipe according to each measurement value is correlated and stored in a database form to build a database for the monitoring result of the pipe. database building step in which processing is performed; a learning step in which, through the control unit, a process of learning the contents of the database is performed using an artificial intelligence learning algorithm including deep learning or machine learning; And through the control unit, based on the learning contents of the learning step, through a regression analysis using an artificial neural network (ANN) to evaluate the condition and safety of the pipe through the safety evaluation step is configured to be automatically performed characterized in that

In addition, according to the present invention, in the pipe monitoring system, a plurality of pipe safety evaluation system installed for each area or facility; A control configured to transmit and receive various data with each of the pipe safety evaluation systems, collect monitoring information, build big data on the status of pipes, and perform a process of providing various types of information customized according to a user's request server; and a user terminal for each user to communicate with the control server to request and receive desired information, wherein the pipe safety evaluation system is configured using the pipe safety evaluation system described above A piping monitoring system is provided.

Here, the user terminal is configured using a terminal device including a PC, or is configured by installing a dedicated application on a personal portable information communication terminal including a smart phone, tablet PC, or notebook computer. do.

As described above, according to the present invention, a sensor unit for detecting displacement and rotation and an MCU for control are disposed inside and outside in one piece with the insulation surrounding the pipe to transmit/receive various data based on IoT. Displacement sensor composed of a sensor, a sensor for measuring strain, and a strain sensor composed of a distributed sensor in which the MCU is placed inside and outside as one piece with the insulation surrounding the pipe and transmits and receives various data based on IoT By providing an IoT-based high-temperature displacement and rotation measuring device, a high-temperature strain measuring device, and a piping safety evaluation system using the same, it monitors the overall condition of the pipe to find vulnerable areas where abnormal deformation or abnormal displacement or torsion occurs The safety of piping can be ensured by performing maintenance.

In addition, according to the present invention, as described above, by installing a displacement sensor for measuring displacement and rotation at regular intervals for each part of the pipe and a strain sensor for measuring the strain, respectively, thermal deformation due to heat or load due to ground or By monitoring the occurrence of displacement due to subsidence of the support device, evaluating the safety of the pipe based on each measured value, and deciding whether to maintain or not according to the evaluation result, it effectively prevents damage to the pipe and secures the safety of the entire facility. By providing an IoT-based high-temperature displacement and rotation measurement device, a high-temperature strain measurement device, and a piping safety evaluation system using the same, a high-temperature plant applied to a high-temperature, high-pressure environment, such as a thermal power plant, for example By measuring the displacement due to subsidence or deformation of the ground or support device due to heat and load due to heat for each part of the pipe, it is possible to find vulnerable parts and perform maintenance to prevent damage to the pipe with relatively simple construction and low cost. can be effectively prevented.

In addition, according to the present invention, as described above, by monitoring the overall condition of the pipe to find the vulnerable part where abnormal deformation or abnormal displacement and torsion occurred, and to perform maintenance on the found vulnerable part in advance, the pipe By providing an IoT-based displacement and rotation measuring device for high temperature, a strain measuring device for high temperature, and a pipe safety evaluation system using the same, which are configured to ensure safety, it is possible to find vulnerable areas where thermal deformation and displacement of the pipe have occurred and prevent damage It is possible to solve the problems of the prior art pipe measuring devices and methods that have not been presented with an apparatus or method capable of doing so.

1 is a block diagram schematically showing the overall configuration of a piping safety evaluation system according to an embodiment of the present invention.
FIG. 2 is a diagram schematically showing a specific configuration of a displacement measuring unit of the piping safety evaluation system according to the embodiment of the present invention shown in FIG. 1 .
3 is a diagram schematically showing the overall configuration of a displacement measuring unit and a strain measuring unit of the piping safety evaluation system according to the embodiment of the present invention shown in FIG. 1 .
4 is a conceptual diagram schematically showing the overall configuration of a piping safety evaluation system according to an embodiment of the present invention.
5 is a diagram schematically showing the load and temperature conditions for considering the plastic deformation and residual stress of the pipe.
6 is a diagram schematically illustrating a numerical analysis technique used in a general local analysis for a straight pipe in a method of the prior art.
7 is a diagram showing information on displacement and torsion (rotation) information and dependent condition application applied in a local stress analysis for a T-type pipe, respectively.
8 is a diagram illustrating boundary conditions for finite element analysis with respect to intuition applied to a performance test for verifying reliability of a finite element analysis method according to an embodiment of the present invention.
9 is a view showing information about intuition applied to a performance test for verifying the reliability of the finite element analysis method according to an embodiment of the present invention, loads, and boundary conditions, respectively, in a table.
10 is a view showing a stress distribution in a circumferential direction as a result of a finite element analysis in a performance test for verifying the reliability of the finite element analysis method according to an embodiment of the present invention.
11 is a view showing the stress distribution in the longitudinal direction as a result of a finite element analysis in a performance test for verifying the reliability of the finite element analysis method according to an embodiment of the present invention.
12 is a view showing the stress distribution of the pipe end section for each analysis step.
13 is a flowchart schematically showing the overall configuration of a method for evaluating the safety of a pipe according to an embodiment of the present invention.
14 is a block diagram schematically illustrating a configuration example of a pipe monitoring system configured using the pipe safety evaluation system according to the embodiment of the present invention shown in FIG. 1 .

Hereinafter, with reference to the accompanying drawings, a specific embodiment of the IoT-based high-temperature displacement and rotation measurement device and high-temperature strain measurement device and the piping safety evaluation system using the same according to the present invention will be described.

Here, it should be noted that the content described below is only one embodiment for carrying out the present invention, and the present invention is not limited to the content of the embodiment described below.

In addition, in the following description of the embodiments of the present invention, for parts that are the same as or similar to those of the prior art, or that can be easily understood and implemented at the level of those skilled in the art, the detailed description is provided for the sake of brevity. It should be noted that , has been omitted.

That is, the present invention, as will be described later, for example, a high-temperature plant pipe applied to a high-temperature, high-pressure environment, such as a thermal power plant, in addition to thermal deformation due to heat, the ground or support due to the load of the pipe itself In order to solve the problem of high-temperature plant piping in the prior art, in which the displacement of the piping occurs due to subsidence or deformation of the device, and when such deformation or displacement becomes severe, the piping is damaged and there is a risk that it may lead to a major accident, IoT-based high temperature configured to ensure the safety of the pipe by monitoring the overall condition of the pipe to find the vulnerable part where abnormal deformation, abnormal displacement, and torsion occurred, and to perform maintenance on the found vulnerable part in advance Displacement and rotation measuring device for high temperature, strain measuring device for high temperature, and piping safety evaluation system using the same.

In addition, the present invention, as will be described later, to monitor the overall condition of the pipe to find the vulnerable part where abnormal deformation or abnormal displacement and torsion occurred, and to ensure the safety of the pipe by performing maintenance in advance. , a displacement sensor consisting of a sensor unit for detecting displacement and rotation, and a distributed sensor that transmits and receives various data based on IoT, where the MCU for control is integrated with the insulation surrounding the pipe, inside and outside, and the strain rate IoT-based high temperature consisting of a sensor unit for measurement and a strain sensor composed of a distributed sensor that transmits and receives various data based on IoT, where the sensor unit for measurement and the MCU for control are placed inside and outside in one piece with the insulation surrounding the pipe Displacement and rotation measuring device for high temperature, strain measuring device for high temperature, and piping safety evaluation system using the same.

In addition, the present invention, as will be described later, by measuring the displacement due to the thermal deformation of the pipe or subsidence or deformation of the ground or support device for each part, find the weak spot and perform maintenance to prevent damage to the pipe in advance. In order to solve the problems of the pipe measuring devices and methods of the prior art, which had limitations in which the measuring device and method for making the Each strain sensor for measurement is installed to monitor the occurrence of displacement due to thermal deformation due to heat or subsidence of the ground or support device due to load. It relates to an IoT-based high-temperature displacement and rotation measuring device and high-temperature strain measuring device, and a pipe safety evaluation system using the same, which are configured to effectively prevent pipe damage and secure the safety of the entire facility by determining whether or not to do so.

Then, with reference to the drawings, the IoT-based high-temperature displacement and rotation measuring device and high-temperature strain measuring device according to the present invention, and the details of the piping safety evaluation system using the same will be described.

First, referring to FIG. 1 , FIG. 1 is a block diagram schematically showing the overall configuration of a pipe safety evaluation system 10 according to an embodiment of the present invention.

As shown in Fig. 1, the pipe safety evaluation system 10 according to the embodiment of the present invention is largely divided, and displacement measurement comprising a plurality of displacement measuring sensors installed at predetermined specific positions or at regular intervals on the pipe. A strain measuring unit 12 comprising a unit 11 and a plurality of strain measuring sensors installed at predetermined specific positions or at regular intervals on a pipe, and another evaluation system ( 10) or the communication unit 13 for transmitting and receiving various data including measurement values with an external device and controlling the respective operations of the displacement measuring unit 11 and the strain measuring unit 12 and the communication unit 13 described above, Based on each measurement value, the safety of the pipe is evaluated and maintenance is decided, and when maintenance is required or an accident or danger such as pipe damage occurs, a notification or warning is sent to the person in charge or related organizations. It may be configured to include a control unit 14 made to be possible.

That is, the piping safety evaluation system 10 according to the embodiment of the present invention, for example, a plurality of displacement sensors and strain sensors at each location for piping installed in a high temperature, high pressure environment, such as a thermal power plant. Each is installed, and information on displacement, rotation angle, and strain is measured at each location of the pipe through each sensor to calculate the local stress, and the change in stress is analyzed using a numerical analysis technique as described below. This may be configured to perform a process for evaluating the safety of the pipe in real time.

Here, in the embodiment of the present invention to be described below, the present invention has been described by taking as an example a case in which the piping safety evaluation system 10 according to the embodiment of the present invention is installed in the piping of a thermal power plant, but the present invention is not necessarily in this case That is, the present invention is not limited to, that is, the present invention can be applied to piping installed in other facilities other than the above-described thermal power plant, etc., as needed within the scope without departing from the spirit and essence of the present invention, appropriately changed by those skilled in the art and it should be noted that it is applicable by modification.

In addition, the displacement measuring unit 11 is configured to include a plurality of displacement sensors 20 for measuring the displacement and rotation angle of the pipe with respect to each position on the pipe, and the strain measuring unit 12 is It may be configured to include a plurality of strain sensors 30 for measuring the strain rate of the pipe for each position on the pipe, wherein each sensor is connected to an external device or to each other through at least one of wired or wireless communication. It may be configured to send and receive data.

In more detail, referring to FIGS. 2 and 3 , FIG. 2 is a view schematically showing a specific configuration of the displacement sensor 20 applied to the piping safety evaluation system 10 according to an embodiment of the present invention, and FIG. 3 is a diagram schematically showing the overall configuration of the displacement sensor 20 and the strain sensor 30 applied to the piping safety evaluation system 10 according to an embodiment of the present invention.

As shown in FIG. 2 , the displacement sensor 20 may be configured as a 6 Degrees of Freedom (DOF) sensor using an accelerometer and a gyro sensor to detect the displacement and rotation of the pipe at the corresponding position. In addition, the laser displacement sensor and the Wi-SUN (Wireless Smart Utility Network) module can be integrally formed on a single substrate (PCB).

At this time, the sensor unit 21 for measurement and the MCU 22 for control may be configured as a separate type, that is, as shown in FIG. The unit 21 is installed and the MCU 22 is disposed outside (about 100° C.), and may be configured as a distributed sensor that transmits and receives measurement values and various data based on the Internet of Things (IoT).

In addition, the strain sensor 30 may be configured using a Fiber Bragg Grating (FBG) strain sensor to detect strain in the pipe at the corresponding position.

In addition, the strain sensor 30 may also be configured as a separate type in which the sensor unit 31 for measurement and the MCU 32 for control, like the displacement sensor 20 described above, are separated, that is, as shown in FIG. 3 , The sensor unit 31 is installed inside the insulating material (about 600°C) surrounding the outside of the pipe, and the MCU 32 is placed outside (about 100°C) to transmit and receive measurement values and various data based on the Internet of Things (IoT). It can be configured as a distributed sensor that

From the configuration as described above, while the conventional strain sensor can measure strain up to 350° C., the strain sensor 30 according to the embodiment of the present invention configured as described above is an FBG sensor for strain measurement up to 600° C. This is a possible advantage.

More specifically, referring to FIG. 4 , FIG. 4 is a conceptual diagram schematically showing the overall configuration of the piping safety evaluation system 10 according to an embodiment of the present invention.

As shown in Figure 4, the pipe safety evaluation system 10 according to the embodiment of the present invention, the displacement sensor 20 and the strain sensor 30 composed of the distributed sensor as described above, respectively, the position of the pipe It is installed in the system and periodically receives the measurement values measured from each sensor to build a database on changes in the condition of the pipe, and performs stress analysis and local stress analysis on the pipe based on digital twin technology. By learning the analysis result using an artificial intelligence learning algorithm such as , machine learning, etc., and performing regression analysis through an artificial neural network (ANN), a series of processing processes to evaluate safety are performed. It can be configured to effectively monitor the current state of the entire pipe and the occurrence of abnormal displacement or deformation.

Subsequently, a detailed description will be given of a method for evaluating the safety of a pipe based on measured values measured through the displacement sensor 20 and the strain sensor 30 configured as described above.

Here, in order to evaluate the safety of the pipe, it is first necessary to calculate the local stress of the pipe. The stress analysis of the pipe is performed, and through this process, it is possible to calculate the plastic deformation of the pipe due to an abnormal displacement that exceeds the design allowable range, and it can be analyzed considering the residual stress of the pipe.

That is, referring to FIG. 5, FIG. 5 is a diagram schematically illustrating load and temperature conditions in consideration of plastic deformation and residual stress of the pipe.

As shown in Fig. 5, the entire analysis is divided into a total of three stages: an installation stage (or over haul), a high-temperature and high-pressure operation stage, and an over haul stage considering only the self-weight state, and each stage displacement and torsion (rotation) ) information, it is possible to simulate the stress acting on the actual pipe.

More specifically, in order to predict the stress of high-temperature and high-pressure piping in actual operation, in general, finite element analysis (FEA) was performed by modeling the entire piping line as a beam element, and the results of the finite element analysis were It is evaluated based on the allowable stress presented in standard standards such as ASME B31.1 and ASME B31.3, and it is performed at the design stage of the pipe.

However, this method can be evaluated conservatively in the calculation of local stress in a branching line, for example, T-shaped piping, and in order to compensate for this, conventionally, the piping is partially modeled with solid elements and evaluated. However, this has the disadvantage that additional settings are required in setting the boundary conditions.

That is, in order to partially model and analyze a pipe, it is important to set the end of the partial modeling, and thus, in the prior art, an additional load in the form of pressure is set at the end of the pipe to simulate the withstand pressure condition, or a straight pipe is installed at the end of the pipe. The connected method was used.

In more detail, referring to FIG. 6 , FIG. 6 is a diagram schematically illustrating a numerical analysis technique used in a general local analysis for straight pipe in the prior art method.

As shown in FIG. 6 , _{the connected pipe can be simulated by setting an additional load F corresponding to the internal pressure P I} of the pipe to the end of the pipe, which can be expressed by a formula as shown in [Equation 1] below.

[Equation 1]

Here, A _I means the inner area of the pipe end.

Therefore, the numerical analysis technique of the prior art as described above is applicable only to a limited case, for example, in the case of a T-type pipe, it is difficult to simulate the pipe connected to the end of the pipe. And since it is difficult to implement torsion, there is also a limitation that the behavior of the pipe in actual operation cannot be simulated.

Accordingly, in the present invention, in order to solve the problems of the prior art as described above, a new numerical analysis technique is proposed that is configured to enable analysis of the entire piping system as well as local piping by utilizing displacement and torsion (rotation) information. did

More specifically, referring to FIG. 7 , FIG. 7 is a view showing information on displacement and torsion (rotation) information and coupling constraint application applied during a local stress analysis for a T-type pipe, respectively.

Here, in FIG. 7 , Δx _i , Δy _i , and Δz _i are the three-dimensional displacements of the pipe end, and ΔMx _i , ΔMy _i , ΔMz _i are the moments of the pipe end, respectively.

In addition, in the numerical analysis, the moment is applied as a rotation angle, and the degree of freedom of the pipe end face is subordinated based on a reference node at the center of the pipe end.

At this time, the coupling type is applied differently depending on the displacement and rotation boundary conditions. must be set as the Displacement type.

Therefore, in the case of high-temperature and high-pressure piping, displacement and rotation boundary conditions must be applied under internal pressure conditions, so the analysis is performed twice for each case. In the analysis, based on the analysis result of the displacement condition under internal pressure, the stress and strain are mapped and the analysis can be configured to apply the rotational boundary condition.

Next, with reference to FIGS. 8 to 12, the experimental results verifying the actual performance of the finite element analysis method according to the embodiment of the present invention configured as described above will be described.

First, referring to FIGS. 8 and 9, FIG. 8 is a boundary condition ( boundary condition), and FIG. 9 is a table showing information about intuition applied to a performance test for verifying the reliability of the finite element analysis method according to an embodiment of the present invention, load, and boundary condition, respectively. It is a drawing.

That is, in order to verify the reliability of the finite element analysis results using displacement and rotation data according to an embodiment of the present invention, the present inventors, as shown in FIG. Numerical analysis was performed for each.

At this time, in order to simulate the effect of connecting the end of the pipe, a displacement of 0.4531 mm corresponding to the inner pressure of 5 MPa was applied without setting a load corresponding to the internal pressure at the end of the pipe as shown in [Equation 1] above.

In addition, the numerical analysis performed in this example was composed of three layers with respect to the thickness of an 8-node solid element, only the elastic region was considered, and the analysis was performed using Abaqus v2019, a commercial analysis program, and the numerical analysis results were It was verified by comparison with the analytical solution, and the shape of the pipe end was confirmed for the analysis results of displacement and rotation conditions.

More specifically, referring to FIGS. 10 and 11 , FIGS. 10 and 11 are views showing the results of the finite element analysis according to the embodiment of the present invention performed as described above, and the stress distribution and length in the circumferential direction The stress distribution in each direction is shown.

As shown in FIGS. 10 and 11, the present inventors divided the results of the finite element analysis into displacement analysis under pressure condition and rotation analysis performed based on the results of displacement analysis, respectively, and only displacement under pressure condition would have been applied. In this case, the circumferential stress was about 49.9 MPa and the longitudinal stress was about 23.82 MPa.

On the other hand, in the case of an analytical solution, it can be calculated as in [Equation 2] and [Equation 3] below, and in this embodiment, the circumferential stress σ _H is 50 MPa, and the longitudinal stress σ _L is 23.81 MPa was calculated as

[Equation 2]

[Equation 3]

Here, P _I is the internal pressure, D _I is the inner diameter of the pipe, and t is the pipe thickness.

As a result of comparison, it was confirmed that the displacement stress under the internal pressure condition showed the effect of the connected piping, and it was confirmed that the rotational displacement condition was rotated by a predetermined angle while the internal pressure and displacement were maintained.

That is, referring to FIG. 12 , FIG. 12 is a view showing the stress distribution of the end surface of the pipe for each analysis step, and it can be confirmed that it is rotated by a predetermined angle while maintaining the displacement under the withstand pressure condition.

As described above, in the present invention, a numerical analysis technique using displacement and torsion (rotation) information was presented to predict the local stress of the pipe currently in operation, and the validity of the intuition was confirmed, therefore, in the present invention According to this, it is possible to evaluate the creep and fatigue life by using the improved numerical analysis technique to evaluate the safety of various high-temperature plant pressure pipes and to accurately evaluate the local stress. it is expected that it will be possible

More specifically, referring to FIG. 13 , FIG. 13 is a flowchart schematically showing the overall configuration of a method for evaluating the safety of a pipe according to an embodiment of the present invention.

As shown in Figure 13, the safety evaluation method of the pipe according to the embodiment of the present invention is largely divided, first, each of the measured values transmitted from the displacement sensors and strain sensors installed in the pipe are received, respectively, in the form of a database. Local stress according to the displacement of the pipe through the finite element analysis (FEA) based on the data collection step (S10) in which the processing to be stored in a separate storage means is performed, and the displacement value of the pipe received in the data collection step (S10) Based on the analysis result of the displacement analysis step (S20) and the displacement analysis step (S20) and the rotation value of the pipe received in the data collection step (S10), finite element analysis (FEA) ) through the rotation analysis step (S30), in which the processing of calculating the local stress according to rotation (torsion) and performing the stress analysis is performed, and the finite element analysis ( Through FEA), a verification step (S40) in which local stress according to strain is calculated and stress analysis is performed to compare and verify with the analysis results of the displacement analysis step (S20) and the rotational analysis step (S30), and each analysis A separate display means such as monitoring the evaluation results of the safety evaluation step (S50) and the safety evaluation step (S50), in which the process of determining whether there is an abnormality in the pipe and whether maintenance is required according to a predetermined standard based on the result is performed At the same time, if it is determined that there is an abnormality, it may be configured to include a notification step (S60) in which a process of delivering a notification of the corresponding fact to a designated contact according to preset contents such as a person in charge or a relevant department is performed.

That is, the control unit 14 is configured to perform the method for evaluating the safety of piping according to the embodiment of the present invention configured as shown in FIG. 13 , and based on the digital twin technology, the piping It may be configured to automatically perform a process for evaluating the safety of

More specifically, the digital twin builds a digital model of a virtualized thing with software instead of an actual physical thing and conducts a simulation (simulation) to conduct a simulation (simulation) of the characteristics of a real thing (current state, productivity, operation). Scenario, etc.) refers to a technology that obtains accurate information about The technology is widely applied.

Accordingly, the control unit 14 receives values measured in real time through each of the displacement sensor 20 and the strain sensor 30 based on this digital twin technology, and based on the received values, each position The safety is evaluated by calculating the local stress on the By configuring the processing to be delivered and responded to automatically, it is possible to secure the safety of the entire pipe with a relatively simple configuration and low cost without the need to inspect the pipe through a separate manpower, and to perform maintenance in a timely manner. The cost of maintenance and management can be reduced, and even when an abnormality such as damage occurs, it can be quickly dealt with to prevent the spread of a large-scale accident in advance.

In addition, the piping safety evaluation system 10 and method according to an embodiment of the present invention collects each measured value and analysis result obtained as described above, and correlates the state of the pipe according to each measured value to form a database To build a database for monitoring results of piping by storing as Accordingly, it may be configured to automatically perform a process of evaluating the condition and safety of a pipe through a regression analysis using a learning result and an artificial neural network (ANN).

Here, learning is performed using an artificial intelligence learning algorithm, such as the deep learning or machine learning described above, and analysis, evaluation, or prediction of input data is performed based on the learning result. For more specific details on operations and processing, those skilled in the art can appropriately implement them with reference to the contents of the prior art. Therefore, it should be noted that the detailed description of the content that can be easily understood and implemented by those skilled in the art has been omitted.

Furthermore, the piping safety evaluation system 10 according to the embodiment of the present invention installs the piping safety evaluation system 10 configured as described above for each area or facility, and each piping safety evaluation system ( 10) and a server 14 for transmitting and receiving various data and a user terminal 15 for providing various information customized according to a user's request, monitoring not only a single facility but also a plurality of facilities in a wide area and an integrated management system capable of providing information according to user requests.

That is, referring to FIG. 14 , FIG. 14 is a diagram schematically showing a configuration example of the pipe monitoring system 40 configured using the pipe safety evaluation system 10 according to the embodiment of the present invention shown in FIG. 1 .

As shown in FIG. 14, the pipe monitoring system 40 according to the embodiment of the present invention is largely divided, for example, a plurality of pipe safety evaluation systems installed in each region or facility, such as a thermal power plant in each region. Process of collecting monitoring information by transmitting and receiving various data to and from each pipe safety evaluation system 10, constructing big data about the state of the pipe, and providing various types of information tailored to the user's request may be configured to include a control server 41 configured to be performed, and a user terminal 42 for each user to communicate with the control server 41 to request and receive desired information.

Here, the user terminal 42, for example, may be configured using a terminal device such as a PC, preferably, a smart phone, a tablet PC, or a laptop computer, such as a personal portable information communication terminal. It may be configured by installing a dedicated application, but the present invention is not necessarily limited to this configuration, that is, the present invention is variously modified as needed by those skilled in the art without departing from the spirit and essence of the present invention. And it should be noted that it can be configured by changing.

Therefore, as described above, according to the present invention, a plurality of pipe safety evaluation systems 10 are installed for each region or facility, and each pipe safety evaluation system 10 communicates with each other to exchange various data. At the same time, according to the request of the control server 41, or according to a predetermined setting, it is configured to periodically transmit the monitoring data to the control server 41, respectively, so that, for example, each It is possible to easily build a large-scale pipe monitoring system 40 for monitoring the pipe condition for the facility.

Therefore, as described above, the IoT-based high-temperature displacement and rotation measurement device and high-temperature strain measurement device and the piping safety evaluation system using the same can be implemented according to the embodiment of the present invention, whereby, according to the present invention, displacement And a displacement sensor consisting of a sensor unit for detecting rotation and a distributed sensor that transmits and receives various data based on IoT, in which the MCU for control is disposed inside and outside in one piece with the insulation surrounding the pipe, and to measure the strain An IoT-based high-temperature displacement and rotation measuring device, which includes a strain sensor and a distributed sensor that transmits and receives various data based on IoT and is placed inside and outside in one piece with the insulating material surrounding the pipe. By providing a high-temperature strain measuring device and a piping safety evaluation system using the same, the overall piping condition is monitored to find vulnerable areas where abnormal deformation, abnormal displacement, and torsion occurred, and maintenance of the piping is performed in advance to ensure the safety of the piping. can do.

In addition, according to the present invention, as described above, by installing a displacement sensor for measuring displacement and rotation at regular intervals for each part of the pipe and a strain sensor for measuring the strain, respectively, thermal deformation due to heat or load due to ground or By monitoring the occurrence of displacement due to subsidence of the support device, evaluating the safety of the pipe based on each measured value, and deciding whether to maintain or not according to the evaluation result, it effectively prevents damage to the pipe and secures the safety of the entire facility. By providing an IoT-based high-temperature displacement and rotation measurement device, a high-temperature strain measurement device, and a piping safety evaluation system using the same, a high-temperature plant applied to a high-temperature, high-pressure environment, such as a thermal power plant, for example By measuring the displacement due to subsidence or deformation of the ground or support device due to heat and load due to heat for each part of the pipe, it is possible to find vulnerable parts and perform maintenance to prevent damage to the pipe with relatively simple construction and low cost. can be effectively prevented.

In addition, according to the present invention, as described above, by monitoring the overall condition of the pipe, finding a vulnerable part where abnormal deformation, abnormal displacement, and torsion occur, and performing maintenance in advance to ensure the safety of the pipe. By providing an IoT-based high-temperature displacement and rotation measuring device, a high-temperature strain measuring device, and a piping safety evaluation system using the same, a device or method that can prevent damage by locating vulnerable areas where thermal deformation and displacement of the pipe has occurred is proposed It is possible to solve the problems of the pipe measuring apparatus and methods of the prior art that were not possible.

As described above, through the embodiment of the present invention as described above, the IoT-based high temperature displacement and rotation measuring device and high temperature strain measuring device and the detailed content of the piping safety evaluation system using the same have been described, but the present invention It is not limited only to the contents described in the above embodiment, and therefore, the present invention is variously modified, changed, combined according to design needs and other various factors by those of ordinary skill in the art to which the present invention pertains. and substitutions are possible.

10. Pipe safety evaluation system 11. Displacement measuring unit
12. Strain measuring unit 13. Communication unit
14. Control unit 20. Displacement sensor
21. Sensor unit 22. MCU
30. Strain sensor 31. Sensor part
32. MCU 40. Pipe monitoring system
41. Server 42. User Terminal

Claims (12)

In the piping safety evaluation system,
Displacement measuring unit for measuring displacement and rotation (torsion) of the pipe;
Strain measuring unit for measuring the strain (strain) of the pipe;
a communication unit for transmitting and receiving various data including measurement values with another evaluation system or an external device through at least one of wired or wireless communication; and
While controlling the operations of the displacement measuring unit, the strain measuring unit, and the communication unit, respectively, the measured values measured in real time through the displacement measuring unit and the strain measuring unit are received and stored in a separate storage means, and a digital twin ( Based on digital twin) technology, by performing Finite Element Analysis (FEA) based on each measurement value, the current state of the entire pipe and occurrence of abnormal displacement or abnormal deformation is monitored, and the monitoring result is If it is out of the predetermined standard value or allowable range, it is judged that an abnormality including pipe damage or maintenance is required, and a notification or warning is sent to the designated contact according to the predetermined setting to respond. It is configured to include a control unit made to be
The control unit is
Each of the measured values transmitted from the respective sensors of the displacement measuring unit and the strain measuring unit are received and stored in a separate storage means in the form of a database,
Based on the displacement value of the pipe measured by the displacement measuring unit, the local stress according to the displacement of the pipe is calculated through finite element analysis (FEA) and a stress analysis is performed,
Based on the results of the stress analysis according to the displacement of the pipe and the rotation value of the pipe measured by the displacement measuring unit, the local stress according to the rotation (torsion) of the pipe is calculated through FEA and stress analysis do,
Based on the strain value of the pipe measured through the strain measuring unit, the local stress according to the strain of the pipe is calculated through finite element analysis (FEA) and stress analysis is performed,
By comparing the stress analysis results for the displacement, rotation, and strain of the pipe according to a predetermined standard, the current state of the entire pipe and the occurrence of abnormal displacement or abnormal deformation are monitored, and the safety is evaluated to determine whether maintenance is required. ,
Various data including measurement values, stress analysis results, and monitoring results obtained in each process are output through a separate display means, and at the same time, when the monitoring results are outside the predetermined reference values or allowable ranges, abnormalities including pipe damage Plumbing safety evaluation system, characterized in that the process of determining that occurrence or maintenance is necessary, and responding to the fact by delivering a notification to the designated contact according to a predetermined setting is automatically performed.
The method of claim 1,
The displacement measuring unit,
Pipe safety evaluation system, characterized in that it comprises a plurality of displacement sensors installed in the pipe at a predetermined position or at a predetermined interval.
3. The method of claim 2,
The displacement sensor is
It consists of 6 Degrees of Freedom (DOF) sensor using accelerometer and gyro sensor to detect displacement and rotation (torsion) of the pipe, respectively.
A sensor unit for measurement is installed inside the insulating material surrounding the outside of the pipe, and a microcontroller unit (MCU) for control is respectively disposed on the outside of the insulating material. A piping safety evaluation system comprising a distributed sensor configured to transmit and receive data.
The method of claim 1,
The strain measuring unit,
Pipe safety evaluation system, characterized in that it comprises a plurality of strain sensors installed in the pipe at a predetermined position or at a predetermined interval.
5. The method of claim 4,
The strain sensor is
It consists of a FBG (Fiber Bragg Grating) sensor for measuring the strain of the pipe,
A sensor unit for measurement is installed inside the insulating material surrounding the outside of the pipe, and a microcontroller unit (MCU) for control is respectively disposed on the outside of the insulating material. A piping safety evaluation system comprising a distributed sensor configured to transmit and receive data.
delete delete The method of claim 1,
The control unit is
Builds a database for monitoring results of piping by collecting each measurement value and analysis result and correlating the state of the piping according to each measurement value and storing it in a database form,
It learns the contents of the database using an artificial intelligence learning algorithm including deep learning or machine learning, and piping through regression analysis using the learning result and artificial neural network (ANN) Pipe safety evaluation system, characterized in that the analysis on the condition of the pipe and the process for evaluating the safety are configured to be automatically performed.
In the piping safety evaluation method using the piping safety evaluation system according to any one of claims 1 to 5 and 8,
a data collection step of receiving, through the control unit of the pipe safety evaluation system, measured values transmitted from each displacement sensor and strain sensor installed in the pipe, respectively, and storing the measured values in a separate storage means in the form of a database;
a displacement analysis step in which, through the control unit, a process of calculating a local stress according to the displacement of the pipe through finite element analysis (FEA) based on the displacement value of the pipe received in the data collection step and performing a stress analysis is performed;
Through the control unit, on the basis of the analysis result of the displacement analysis step and the rotation value of the pipe received in the data collection step, the local stress according to rotation (torsion) is calculated through FEA, and the stress analysis is performed. a rotation analysis step in which processing is performed;
Through the control unit, the local stress according to the strain is calculated through finite element analysis (FEA) based on the strain value of the pipe received in the data collection step, and the stress analysis is performed to analyze the displacement analysis step and the rotation analysis step a verification step in which a verification process by comparison with a result is performed;
a safety evaluation step in which, through the control unit, a process of determining whether there is an abnormality in the pipe and whether maintenance is required is performed according to a predetermined standard based on each analysis result; and
Through the control unit, the evaluation result of the safety evaluation step is output through a separate display means, and at the same time, when it is determined that there is an abnormality, a process of delivering a notification about the fact to a predetermined contact information according to preset contents is performed Pipe safety evaluation method, characterized in that configured to be carried out processing including the notification step.
10. The method of claim 9,
The method is
Through the control unit, each measurement value and analysis result is collected, and the state of the pipe according to each measurement value is correlated and stored in the form of a database, thereby establishing a database for the monitoring result of the pipe. step;
a learning step in which, through the control unit, a process of learning the contents of the database is performed using an artificial intelligence learning algorithm including deep learning or machine learning; and
Through the control unit, based on the learning contents of the learning step, through regression analysis using an artificial neural network (ANN), the process including the safety evaluation step in which the evaluation of the condition and safety of the pipe is performed automatically is configured to be performed Pipe safety evaluation method characterized by.
In the pipe monitoring system,
A plurality of piping safety evaluation systems installed for each area or facility;
A control configured to transmit and receive various data with each of the pipe safety evaluation systems, collect monitoring information, build big data on the condition of the pipe, and perform a process of providing various types of information customized according to a user's request server; and
Each user communicates with the control server and is configured to include a user terminal for requesting and receiving desired information,
The pipe safety evaluation system,
A pipe monitoring system, characterized in that it is configured using the pipe safety evaluation system according to any one of claims 1 to 5 and 8.
12. The method of claim 11,
The user terminal,
It is configured using a terminal device including a PC, or
Or, a pipe monitoring system, characterized in that configured by installing a dedicated application on a personal portable information communication terminal including a smart phone or tablet PC or a notebook computer.

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