Evaluation system, evaluation method, and evaluation program

Abstract

To correct a measured value by taking into account a state of a facility including an evaluation object place.SOLUTION: An evaluation system evaluates an evaluation object place to which a pulse eddy current probe 2 is attached, and comprises: the pulse eddy current probe 2 having a transmission coil and a reception coil; at least one probe control device 4; and a server device 5. The probe control device 4 can realize: a calculation function of calculating duration of induction current that is induced by pulse current flowing in the transmission coil and that is generated in the reception coil; and a transmission function of transmitting the duration to the server device 5. The server device 5 can realize: a state specification function of specifying a state of a facility including an evaluation object place based on temperature of the evaluation object place; and a correction function of obtaining a corrected value by correcting the duration received from the probe control device 4 on the basis of the specified facility state in the state specification function, and the temperature of the evaluation object place.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an evaluation system, an evaluation method, and an evaluation program. [Background technology]

[0002] Pulsed eddy current testing is a commonly used method for non-destructively evaluating the presence or absence of flaws and thickness of a metal object. In pulsed eddy current testing, a probe (transmitting coil) that generates a magnetic field by continuously passing an alternating current through it is brought close to the metal object to be measured, generating eddy currents, and the magnetic field generated by these eddy currents is detected by a probe (receiving coil). The eddy currents generated in the metal object reflect the presence or absence of flaws and thickness of the object, so the presence or absence of flaws and thickness can be detected based on the signal detected by the probe.

[0003] However, factors that affect the signal detected by the receiving coil are not limited to the presence or absence of flaws in the object being evaluated or its thickness. For example, the temperature of the object being evaluated affects the magnitude of the detected signal. Therefore, in order to accurately evaluate the object being evaluated using pulsed eddy current flaw detection, it is necessary to eliminate the influence of fluctuations in the detected signal due to factors such as temperature.

[0004] For example, Japanese Patent Application Laid-Open No. 2012-32180 (Patent Document 1) discloses an eddy current flaw detector that corrects the sensitivity of a coil's detection signal based on coil operation information obtained on the object under test. According to the invention described in Patent Document 1, the detection signal is corrected based on actual measurements of the surface shape of the object under test, enabling highly accurate flaw detection. Furthermore, Japanese Patent Application Laid-Open No. 61-117402 (Patent Document 2) discloses a technique for correcting the measurement value of an eddy current non-contact displacement meter based on data on temperature-displacement characteristics that have been specified in advance. According to the invention described in Patent Document 2, it is possible to eliminate the effect of the temperature of the measurement site on the measurement value. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-32180 [Patent Document 2] Japanese Patent Application Laid-Open No. 61-117402 Summary of the Invention [Problem to be solved by the invention]

[0006] Intermittently operated equipment in petrochemical plants and the like can become hot when in operation and cold (around room temperature, for example) when shut down. When applying pulsed eddy current testing to such equipment, the difference in behavior between when the equipment is in operation and when it is shut down poses a problem. If measurements taken both when the equipment is in operation and when it is shut down could be used, the number of data points available for evaluation would increase, improving the accuracy of equipment monitoring. However, the inventions described in Patent Documents 1 and 2 did not take into consideration the collective handling of data representing different equipment states at the time of acquisition.

[0007] Therefore, it is desirable to realize an evaluation system, evaluation method, and evaluation program that can correct measurement values ​​by taking into account the state of the equipment including the location to be evaluated. [Means for solving the problem]

[0008] An evaluation system according to the present invention comprises a pulsed eddy current probe having a transmitting coil and a receiving coil, at least one probe control device that controls the pulsed eddy current probe, and a server device that can communicate with the probe control device, and is used to evaluate an evaluation location to which the pulsed eddy current probe is attached, wherein the probe control device is capable of realizing a calculation function that calculates the duration of an induced current that is generated in the receiving coil as a result of being induced by a pulsed current flowing in the transmitting coil, and a transmission function that transmits the duration to the server device, and the server device is capable of realizing a condition identification function that identifies a condition of equipment including the evaluation location based on the temperature of the evaluation location, and a correction function that obtains a corrected value by correcting the duration received from the probe control device based on the condition of the equipment identified by the condition identification function and the temperature of the evaluation location.

[0009] The evaluation method according to the present invention is an evaluation method for evaluating an evaluation target location to which a pulse eddy current probe having a transmitting coil and a receiving coil is attached, and is characterized by including: a calculation step for calculating the duration of an induced current generated in the receiving coil as a result of being induced by a pulse current flowing in the transmitting coil; a state identification step for identifying the state of equipment including the evaluation target location based on the temperature of the evaluation target location; and a correction step for correcting the duration calculated in the calculation step based on the state of the equipment identified in the state identification step and the temperature of the evaluation target location to obtain a corrected value.

[0010] The evaluation program according to the present invention is an evaluation program that is executed by a computing device capable of communicating with a pulse eddy current probe having a transmitting coil and a receiving coil, and that evaluates an evaluation target location to which the pulse eddy current probe is attached. When executed by the computing device, the evaluation program is capable of realizing a calculation function that calculates the duration of an induced current that is generated in the receiving coil as a result of being induced by a pulse current flowing in the transmitting coil, a state identification function that identifies the state of equipment including the evaluation target location based on the temperature of the evaluation target location, and a correction function that corrects the duration calculated by the calculation function based on the operating state identified by the state identification function and the temperature of the evaluation target location to obtain a corrected value.

[0011] These configurations allow the measurement values ​​to be corrected taking into account the state of the equipment, including the location being evaluated, so that measurements taken when the equipment was in a different state can be handled consistently. This makes it easier to increase the number of data points used for evaluation and improve the accuracy of equipment monitoring.

[0012] Preferred embodiments of the present invention will be described below, but the scope of the present invention is not limited to the preferred embodiments described below.

[0013] In one aspect, the evaluation system of the present invention further includes a temperature measuring device that measures the temperature of the location to be evaluated, and it is preferable that the server device, in the state identification function, identifies the state of the equipment based on the temperature of the location to be evaluated measured by the temperature measuring device.

[0014] According to this configuration, the evaluation system itself includes a temperature measuring device, so that the location where the temperature is measured can be easily set to a location suitable for evaluation.

[0015] In one aspect of the evaluation system of the present invention, the probe control device can further realize an acquisition function for acquiring the temperature of the evaluation location measured by the temperature measurement device, and the transmission function preferably transmits the duration and the temperature of the evaluation location to the server device, and the server device preferably identifies the operating state of the equipment based on the temperature of the evaluation location received from the probe control device in the state identification function.

[0016] This configuration improves the efficiency of calculation processing in the probe control device and the server device.

[0017] In one aspect of the evaluation system of the present invention, it is preferable that the server device, in the correction function, corrects the duration based on the state of the equipment identified in the state identification function, the temperature of the location to be evaluated, and the ambient temperature of the location to be evaluated.

[0018] According to this configuration, the temperature around the location to be evaluated is further taken into consideration in the correction, thereby further improving the accuracy of the evaluation.

[0019] In one aspect of the evaluation system of the present invention, it is preferable that the server device, in the correction function, corrects the duration based on the state of the equipment identified in the state identification function, the temperature of the location to be evaluated, and the voltage generated in the transmitting coil.

[0020] According to this configuration, the voltage generated in the transmitting coil is further taken into consideration in the correction, thereby further increasing the accuracy of the evaluation.

[0021] In one aspect of the evaluation system according to the present invention, it is preferable that the server device, in the state identification function, selects the state of the equipment from the group consisting of an operating state in which the equipment is operating stably, a stopped state in which the equipment is stopped stably, and a transition state which is a state between the end of operation of the equipment in the operating state and the end of the stopped state, or between the start of operation of the equipment in the stopped state and the end of the operating state.

[0022] This configuration makes it possible to cover typical conditions in equipment that operates intermittently.

[0023] In one aspect of the evaluation system of the present invention, when the server device identifies that the equipment is in the transition state using the state identification function, it is preferable that the correction function performs a correction to convert the duration received from the probe control device into a value that satisfies specified conditions.

[0024] According to this configuration, measurement values ​​in a transition state that is not suitable as evaluation material can be excluded from the evaluation material.

[0025] In one aspect, the evaluation method according to the present invention further includes an evaluation step of evaluating the evaluation target location based on the correction value, and in the state identification step, the state of the equipment is selected from the group consisting of an operating state in which the equipment is operating stably, a stopped state in which the equipment is stopped stably, and a transition state which is a state between the end of operation of the equipment in the operating state and the start of operation of the equipment in the stopped state and the start of operation of the equipment in the operating state, and it is preferable that in the evaluation step, the correction value for the duration acquired at the time when the state of the equipment is identified as being in the transition state in the state identification step is excluded from the correction value used for evaluation.

[0026] According to this configuration, measurement values ​​in a transition state that is not suitable as evaluation material can be excluded from the evaluation material.

[0027] Further features and advantages of the present invention will become more apparent from the following description of exemplary and non-limiting embodiments, which is given with reference to the drawings. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a diagram illustrating an overview of an evaluation system according to an embodiment. [Figure 2] 1 is a block diagram showing a configuration of an evaluation system according to an embodiment. [Figure 3] FIG. 10 is a diagram showing an example of an attenuation curve of an induced current. [Figure 4] FIG. 10 is a diagram showing the relationship between the state of the equipment and the temperature of the location to be evaluated. [Figure 5] FIG. 10 is a diagram illustrating an example of transition of the duration of an induced current. [Figure 6] FIG. 10 is a diagram illustrating an example of a transition of a correction value for the duration of an induced current. [Figure 7] 10A and 10B are diagrams illustrating an example of the behavior of a wall thickness phenomenon. DETAILED DESCRIPTION OF THE INVENTION

[0029] An evaluation system, an evaluation method, and an evaluation program according to the present invention will be described below with reference to the drawings. In the following, an example will be described in which the evaluation system according to the present invention is applied to an evaluation system 1 that evaluates a pipe T through which crude oil or the like flows in a petrochemical plant.

[0030] [Configuration of evaluation system] The evaluation system 1 according to this embodiment includes a pulse eddy current probe 2, a temperature measuring device 3, a probe control device 4, and a server device 5 (FIGS. 1 and 2).

[0031] The pipe T to be evaluated is connected to the secondary side of a pump P, and high-temperature crude oil, etc. flows through it when the pump P is operating. The pipe T is corroded by the flowing crude oil, etc., and its wall thickness gradually decreases. In this embodiment, the pipe T and the pump P are collectively referred to as "equipment."

[0032] The evaluation system 1 is used to detect trends in changes (reductions) in wall thickness at the location being evaluated, leading to the discovery of abnormalities and repairs. At the location being evaluated on the pipe T, a pulse eddy current probe 2 is attached to the outside of the thermal insulation jacket of the pipe T, and a temperature measuring device 3 is attached to the inside of the thermal insulation jacket. Note that the thermal insulation jacket is not shown in Figure 1.

[0033] The pulsed eddy current probe 2 has a transmitting coil 21, a receiving coil 22, and a microcontroller 23. The pulsed eddy current probe 2 is connected to a probe control device 4. The connection between the pulsed eddy current probe 2 and the probe control device 4 may be wired or wireless.

[0034] The microcontroller 23 controls the transmission coil 21 to pass a pulse current in accordance with a control signal from the probe control device 4. When the pulse current passes through the transmission coil 21, a magnetic field is generated, and this magnetic field generates an induced current (eddy current) at the location to be evaluated where the pulse eddy current probe 2 comes into contact.

[0035] The magnetic field generated by the induced current generates an induced current in the receiving coil 22. The microcontroller 23 detects the induced current generated in the receiving coil 22. An example of the attenuation curve of the detected induced current is shown in FIG.

[0036] In the following description, the series of operations in which the microcontroller 23 controls the transmitting coil 21 to pass a pulse current and detects the induced current generated in the receiving coil 22 may be referred to as "performing measurement."

[0037] The temperature measuring device 3 is a device that measures the temperature of the location to be evaluated, and may be a known device such as a thermocouple. The temperature measuring device 3 is connected to the probe control device 4. The connection between the temperature measuring device 3 and the probe control device 4 may be wired or wireless.

[0038] The probe control device 4 is a control device that controls the pulse eddy current probe 2 and is implemented as, for example, a microcontroller. The probe control device 4 is connected to the pulse eddy current probe 2 and the temperature measuring device 3, and is capable of communicating with a server device 5. The probe control device 4 receives power from a power source (not shown) to operate, and also supplies power to each pulse eddy current probe 2 and temperature measuring device 3. The functions of the probe control device 4 will be described later.

[0039] The server device 5 is a computer configured to be able to communicate with the probe control device 4, and is typically a server-type computer. The probe control device 4 and the server device 5 may be directly connected or may be connected via a network such as an intranet or the Internet, but in this embodiment, an example is shown in which they are connected via the network N. The functions of the server device 5 will be described later.

[0040] [Evaluation process] Before describing the functions of the probe control device 4 and the server device 5, we will explain the general flow of evaluating an evaluation target portion of a pipe T using the evaluation system 1 according to this embodiment. In the evaluation according to this embodiment, the duration τ and temperature of the evaluation target portion of the pipe T are measured periodically (e.g., every few hours) over a predetermined period of time, and the measurement results are accumulated. Because the duration τ is roughly proportional to the wall thickness of the evaluation target portion of the pipe T, the trend of the accumulated duration τ can be used to grasp the trend of change (decrease) in the wall thickness of the evaluation target portion. However, the value of the duration τ obtained by each measurement is affected by the temperature of the evaluation target portion. Therefore, it is usually difficult to directly compare the trend of the duration τ when the equipment is operating with the trend of the duration τ when the equipment is stopped. Therefore, in this embodiment, the duration τ is corrected taking into account the state of the equipment, and the evaluation target portion is evaluated taking into account the duration τ measured under different conditions.

[0041] [Functions of the probe control device] The probe control device 4 can realize a control function for controlling the pulse eddy current probe 2, an acquisition function for acquiring measurement values ​​used for evaluating the evaluation target location, a calculation function for calculating the duration of the induced current, a data generation function for generating data to be transmitted to the server device 5, and a transmission function for transmitting data to the server device 5. The functions of the probe control device 4 correspond to the respective steps of the evaluation method according to this embodiment.

[0042] (1-1) Control function The control function is a function for controlling the pulsed eddy current probe 2 to perform measurements. The probe control device 4 sends a control signal to the pulsed eddy current probe 2 to control it to perform a series of operations for performing measurements. Upon receiving this control signal, the microcontroller 23 causes a pulsed current to flow through the transmitting coil 21, and the resulting induced current is received by the receiving coil 22. The current value of the induced current received by the receiving coil 22 is input to the probe control device 4.

[0043] (1-2) Acquisition function The acquisition function is a function for acquiring measured values ​​used for evaluating the evaluation target location. In this embodiment, the current value of the induced current received by the receiving coil 22, the voltage generated in the transmitting coil 21, and the temperature (temperature of the evaluation target location) measured by the temperature measurement device 3 are acquired. Regarding the current value of the induced current, the time transition of the current value of the induced current received by the receiving coil 22 is acquired. Multiple pairs of time and current value are acquired, and data that can identify the attenuation curve of the induced current (FIG. 3) is obtained.

[0044] (1-3) Calculation function (calculation process) The calculation function is a function for calculating the duration τ of the induced current generated in the receiving coil 22 as a result of being induced by the pulse current flowing through the transmitting coil 21. The decay curve of the induced current (FIG. 3) is divided into a straight line portion S1, which decays linearly, and a curved line portion S2, which decays more rapidly than the straight line portion S1. The probe control device 4 analyzes the shape of the decay curve to identify the time of the boundary between the straight line portion S1 and the curved line portion S2, and determines the duration τ based on this.

[0045] One duration τ is calculated by implementing the control function, acquisition function (acquisition of the current value of the induced current), and calculation function. In one measurement, these three functions are implemented multiple times, and the duration τ is calculated multiple times. Therefore, the time required for one measurement is the time required to measure the induced current and calculate the duration τ multiple times. As an example, if the above function combination is implemented 100 times in one measurement, the time required for one measurement will be approximately 5 to 10 minutes.

[0046] The voltage and temperature are acquired multiple times while the duration τ is calculated multiple times (5 to 10 minutes in the above example). However, the frequency of acquiring the voltage and temperature may be less than the frequency of measuring the induced current value. The induced current value is a value whose fluctuation between measurements is technically significant, so measurements must be made at short time intervals (for example, milliseconds). In contrast, the temperature of the evaluation target location changes over a longer time scale than the induced current value, so it is usually not necessary to measure it as frequently as the current value. Furthermore, the voltage is a value that fluctuates due to the temperature of the pulse eddy current probe 2, and the time scale over which it changes is similar to that of the temperature of the evaluation target location, so it is usually not necessary to measure it as frequently as the current value.

[0047] (1-4) Data generation function The data generation function is a function that generates data to be transmitted to the server device 5 based on the duration τ calculated by the calculation function and the voltage and temperature acquired by the acquisition function.

[0048] As described above, the calculation of the duration τ is performed multiple times (e.g., 100 times) in one measurement, and the amount of duration τ (e.g., 100 points) corresponding to the number of times is obtained. A process of extracting features for these multiple durations τ is performed, and the extracted features are transmitted to the server device 5. The feature may be one or more values ​​selected from, for example, the average, median, maximum, minimum, etc. of the durations τ of the multiple points. However, it is preferable that the representative value of the duration τ includes the average value. The following description is based on the assumption that the average value of the durations τ is specified as the representative value.

[0049] Regarding the voltage, a value that can represent the voltage generated in the transmitting coil 21 during one measurement (5 to 10 minutes in the above example) is identified, and this value is used as the data to be transmitted to the server device 5. The representative voltage value can be one or more values ​​selected from the average, median, maximum, minimum, etc. of the voltages at multiple points. The following description is based on the assumption that the average voltage value is identified as the representative value.

[0050] Regarding temperature, a value that can represent the temperature of the location to be evaluated during one measurement (5 to 10 minutes in the above example) is identified, and this is used as the data to be transmitted to the server device 5. The representative temperature value can be one or more values ​​selected from the average, median, maximum, minimum, etc. of the temperatures at multiple points. However, it is preferable that the representative temperature value include the average value and the amount of change. The following explanation will be given on the assumption that these values ​​have been identified as representative values.

[0051] Additionally, a representative time is specified to indicate the time when the duration τ, voltage, and temperature were acquired. This time may be a time that represents one measurement (5 to 10 minutes in the above example), and may be, for example, the start or end time of the measurement.

[0052] (1-5) Transmission function The transmission function is a function for transmitting data to the server device 5. The representative values ​​of the duration τ, voltage, and temperature generated by the data generation function are transmitted to the server device 5 together with the representative value of time. These representative values ​​are stored in the server device 5.

[0053] [Functions of the server device] The server device 5 can realize a state identification function for identifying the state of the equipment, a correction function for correcting the duration τ received from the probe control device 4 to obtain a corrected value, and a display data generation function for generating data for displaying the progress of the corrected value of the duration τ. The functions of the server device 5 correspond to the respective steps of the evaluation method according to this embodiment. As mentioned above, the duration τ, voltage, temperature, and time transmitted from the probe control device 4 to the server device 5 are representative values, but hereinafter, this will not be described as being representative values.

[0054] (2-1) Status identification function (status identification process) The state identification function is a function for identifying the state of the equipment including the piping T including the evaluation target location and the pump P connected thereto. The operating state changes mainly depending on the state of the pump P (operating or stopped) and the time elapsed since the state of the pump P changed. The operating state is identified based on the temperature measured by the temperature measurement device 3.

[0055] Figure 4 is a diagram that shows a schematic diagram of the temperature change at the evaluation location during equipment operation. When pump P is operating, high-temperature fluid flows through pipe T, causing the temperature at the evaluation location to gradually rise, eventually reaching the same temperature as the fluid. On the other hand, when pump P is stopped, there is no heat source to heat pipe T, so the temperature at the evaluation location gradually drops toward a range that is the same level as the ambient temperature (air temperature, room temperature, etc.). Based on this relationship between the operating state and temperature, the state of the equipment can be classified into three states: operating state, stopped state, and transition state.

[0056] The operating state is a state in which the equipment is operating stably (Fig. 4: Pac). In other words, a certain amount of time has passed since the start of operation of pump P, and the temperature of the evaluation point is stable in a high temperature range similar to the temperature of the fluid. Therefore, if the average value of the temperature of the evaluation point during one measurement is higher than a predetermined threshold, and the absolute value of the temperature change of the evaluation point during one measurement is smaller than the predetermined threshold, the equipment is determined to be in an operating state.

[0057] The stopped state is a state in which the equipment is stopped stably (Fig. 4: Pst). That is, a certain amount of time has passed since the operation of pump P was stopped, and the temperature of the evaluation location is stable in a low temperature range similar to the ambient temperature. Therefore, if the average value of the temperature of the evaluation location during one measurement is lower than a predetermined threshold, and the absolute value of the temperature change of the evaluation location during one measurement is smaller than a predetermined threshold, the equipment is determined to be in a stopped state.

[0058] The transition state is the state in which equipment in an operating state stops operation and transitions to a stopped state (Fig. 4: Ptr1), or the state in which equipment in a stopped state starts operation and transitions to an operating state (Fig. 4: Ptr2). In the transition state, the temperature of the evaluation location either drops from the high temperature range (operating state) to the low temperature range (stopped state), or rises from the low temperature range to the high temperature range. Therefore, if the absolute value of the temperature change in the evaluation location during a single measurement is greater than a specified threshold, the equipment is identified as being in a transition state.

[0059] More specifically, the operating state is identified in the state identification function based on the following equations (1) to (4).

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[0060] For equations (1) and (2), T ave is the average temperature of the evaluation point during one measurement, and T acis the threshold value that represents the lower limit of the temperature of the evaluation point during operation, and T st is a threshold value that represents the upper limit of the temperature of the evaluation location in the stopped state. Therefore, equations (1) and (2) compare the temperature of the evaluation location with the respective thresholds for the operating state and the stopped state.

[0061] For equations (3) and (4), T start and T end , are the initial and final values ​​of the temperature at the evaluation point during one measurement, respectively. Therefore, the left-hand sides of equations (3) and (4) represent the absolute value of the change in temperature at the evaluation point during one measurement. ΔT ac is the threshold value that represents the upper limit of the temperature change amount of the evaluation target point during operation, and ΔT st is a threshold value that represents the upper limit of the amount of change in temperature at the location being evaluated when the vehicle is stopped. Therefore, equations (3) and (4) compare the amount of change in temperature at the location being evaluated with the threshold values ​​for the amount of change related to the operating state and the stopped state. Note that, since the range of temperature variation in a steady state differs between the high temperature range (operating state) and the low temperature range (stopped state), the threshold value that represents the upper limit of the amount of change is calculated by ΔT corresponding to the operating state. ac and ΔT corresponding to the stopped state st There are two options available:

[0062] T ac , T st , ΔT ac , and ΔT st are constants that are experimentally determined, and for example, the equipment is operated and stopped multiple times as a preliminary test, and each constant is determined based on the actual temperature measurements during the test.

[0063] If equations (1) and (3) are satisfied, the equipment is identified as being in an operating state. In this case, the value "1" is stored in the operating state flag Fac, and the value "0" is stored in the stopped state flag Fst. If equations (2) and (4) are satisfied, the equipment is identified as being in a stopped state. In this case, the value "0" is stored in the operating state flag Fac, and the value "1" is stored in the stopped state flag Fst. If none of the above applies, the equipment is identified as being in a transition state. In this case, the value "0" is stored in both the operating state flag Fac and the stopped state flag Fst.

[0064] (2-2) Correction function (correction process) The correction function is a function that corrects the average value of the duration τ received from the probe control device 4 to obtain a corrected value. As mentioned above, the duration τ is roughly proportional to the wall thickness of the pipe T at the location being evaluated, but the wall thickness is not the only factor that affects the duration τ. For example, the duration τ tends to become shorter as the temperature of the location being evaluated increases. In addition, the voltage generated in the transmitting coil 21 during measurement also affects the duration τ. The correction function performs correction to mitigate the effects of other factors so that changes in the duration τ caused by changes in wall thickness can be captured.

[0065] The model formula (5) used for correction in the correction function is a model formula that includes a term based on the operating state identified by the state identification function, a term based on the temperature of the evaluation target location, a term based on the ambient temperature, a term based on the voltage generated in the transmitting coil 21, a constant term, and a term based on the passage of time. The model formula (5) is applied to each measurement to obtain the value Y of the model formula. k Calculate.

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[0066] First, we will discuss matters common to each section. k is a subscript and represents each measurement. A letter with a hat (^) represents the initial value of the parameter represented by that letter. The initial value is the value of the parameter (or a value that can be considered equivalent) when the equipment is in an unused state (or a state close to that), and is, for example, the average value of the parameter for a specified period (e.g., one month) after the equipment is installed. In other words, the initial value represents the state of the equipment when it is first installed, before any phenomena associated with its use (such as a reduction in the wall thickness of pipe T) occur. The subscript ac represents a coefficient or variable used for correction in the operating state, and the subscript st represents a coefficient or variable used for correction in the stopped state.

[0067] Fac and Fst are the operating state flag and the stopped state flag, respectively. Either Fac or Fst is 1 (operating state or stopped state), or both are 0 (transition state).

[0068] The duration τ is as described above, that is, the duration τ calculated by the calculation function. In model formula (5), the initial value of the duration τ is referenced. The initial value of the duration τ is, for example, the average value of the duration τ over a predetermined period (e.g., one month) after the equipment is installed, and correlates with the wall thickness of the pipe T before the wall thickness reduction occurs.

[0069] Coefficient A(A ac , A st The term including A is a correction term based on the temperature of the evaluation target location. ac and A st are the correction coefficients, and Tm is the temperature of the location to be evaluated. Tm is specified as the measurement value of the temperature measuring device 3.

[0070] Coefficient B(B ac , B st The term including B is a correction term based on the ambient temperature of the evaluation target area. ac and B stare correction coefficients, and Tb is the ambient temperature of the evaluation target location. Tb is specified as the measurement value of a thermometer (not shown) placed around the evaluation target location, for example.

[0071] Coefficient C(C ac , C st ) is a correction term based on the temperature of the pulsed eddy current probe 2. ac and C st are correction coefficients, and Vx is the voltage generated in the transmitting coil 21. Vx is specified as a measured value of the voltage generated in the transmitting coil 21.

[0072] Coefficient D(D ac , D st ) is a constant term.

[0073] Coefficient E(E ac , E st ) is a correction term based on the passage of time at the location being evaluated. The pipe T is corroded by circulating crude oil, etc., and the wall thickness gradually decreases. Equipment including the pipe T is often used under a certain range of conditions for fluid, temperature, flow rate, etc., so the rate at which the wall thickness decreases is roughly constant. Therefore, the amount of decrease in the wall thickness of the pipe T is roughly proportional to the usage time of the pipe T. The evaluation system 1 according to this embodiment performs the necessary correction to extract and evaluate the component based on the decrease in the wall thickness of the pipe T over time from the transition of the duration τ.

[0074] The coefficients A to E can be determined by, for example, the least squares method. That is, the duration τ based on the actual measurement of the eddy current (the duration τ calculated by the calculation function) and the value Y of the model formula are calculated. k The coefficients A to E are determined so that the sum of the errors Err (Equation (6)) is minimized.

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[0075] The duration τ is corrected using coefficients A to D among the obtained coefficients A to E. Correction value τ of duration τ cis calculated by the following formula (7).

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[0076] As described above, the correction function corrects the duration τ based on the operating state identified by the state identification function, the temperature of the evaluation target location, the ambient temperature, and the voltage generated in the transmission coil 21. The correction value τ of the duration τ c Since the correlation is essentially only with the component based on the decrease in the wall thickness of the pipe T over time, the value when the equipment is in operation and the value when it is stopped can be directly compared. In addition, the duration τ when the equipment is in a transition state that is not suitable as a material for evaluating the evaluation target part is corrected by multiplying it by 0, and the corrected value τ c becomes 0 (an example of a value that satisfies the predetermined condition). As a result, the correction value τ c can be excluded from the set of values ​​to be evaluated.

[0077] (2-3) Display data generation function The display data generation function calculates the correction value τ of the duration τ. c This is a function to generate data (hereinafter referred to as display data) for displaying the transition of the correction value τ c The display device that displays the progress of the data is arbitrary and can be a display device such as an LCD display provided on the server device itself or on a terminal (personal computer, tablet terminal, smartphone, etc.) that accesses the server device and obtains the data.

[0078] The display data may include, for example, the time when the current value of the induced current was acquired, the correction value τ of the duration τ calculated from the current value, c , and the values ​​of the operating state flag Fac and the stopped state flag Fst. c The transition of the correction value τ can be displayed in any format such as a table or a graph. cSince is correlated with the decrease in the wall thickness of the pipe T over time, the correction value τ c The transition of represents the transition of the thickness of the evaluation target portion. In addition, since the display data includes the values ​​of the operating state flag Fac and the stop state flag Fst, the correction value τ c and the correction value τ in the stopped state c It is possible to distinguish between the above and the above.

[0079] (2-4) Piping evaluation (evaluation process) The display data generated by the display data generation function is used to calculate the correction value τ c By displaying the transition of the thickness of the pipe T, the behavior of the wall thickness phenomenon of the pipe T can be evaluated. Note that this evaluation may be performed by a user of the evaluation system or by the evaluation system itself. An embodiment in which the evaluation is performed by a user of the evaluation system will be described below.

[0080] An example of the transition of duration τ is shown in Figure 5. Figure 5 shows that the numerical range of duration τ differs depending on the time of day. When the equipment is stopped, duration τ takes a relatively high value, and when the equipment is operating, duration τ takes a relatively low value. This is because the temperature of the evaluation point is higher when the equipment is operating than when it is stopped, and the higher the temperature, the shorter the duration τ tends to be. Note that when duration τ is between the high and low numerical ranges, the equipment is in a transition state. As such, the numerical range of duration τ differs depending on the state of the equipment, so directly comparing duration τ in different states is not valid for evaluating wall thickness.

[0081] Correction value τ for duration τ c An example of the transition of the correction value τ c is in a certain range or is 0. c Since the effect of temperature differences and other factors on the duration τ is removed, the value is in the same range regardless of the equipment condition. cBy using this, measurements taken in an operating state and measurements taken in a stopped state can be evaluated using the same evaluation criteria. This makes it possible to obtain effective measurements for understanding the transition in wall thickness not only in an operating state but also in a stopped state, making it easier to understand the transition in wall thickness. Note that measurements taken when the equipment is in a transition state are not suitable as evaluation material, so the correction value τ c By setting τ to 0, the correction value τ c The plot in Figure 6 provides a visual understanding of which measurements should be excluded from the evaluation.

[0082] The data used to create the plot in FIG. 6 includes information on the values ​​of the operating state flag Fac and the stopped state flag Fst for each data point. Using this information, the correction value τ c and the correction value τ in the stopped state c and can be displayed in different display modes (different plot shapes, colors, sizes, etc.).

[0083] 7 is a diagram showing an example of the transition of the wall thickness. In FIG. 7, the correction value τ c The thickness Th calculated from the correction value τ c0 The vertical axis shows the ratio Th / Th0, calculated by dividing the ratio by the wall thickness Th0. The measurement period in Figure 7 was 150 days. The ratio Th / Th0 shows a clear decreasing trend over time. By considering the slope of this decreasing trend and the allowable limit of wall thickness reduction at the location being evaluated, it is possible to predict when the pipe should be replaced.

[0084] Other Embodiments Finally, other embodiments of the evaluation system, evaluation method, and evaluation program according to the present invention will be described. Note that the configurations disclosed in the following embodiments can be applied in combination with the configurations disclosed in other embodiments, as long as no contradiction occurs.

[0085] In the above embodiment, an example has been described in which the evaluation system 1 includes a temperature measuring device 3, and the measurement value of the temperature measuring device 3 is used for evaluation. However, in the present invention, the method of acquiring the temperature of the evaluation target location is not limited. For example, the measurement value of a thermometer installed for process management of equipment including the evaluation target location may be acquired as the temperature of the evaluation target location.

[0086] In the above embodiment, the probe control device 4 transmits a representative value of the temperature measured by the temperature measurement device 3 to the server device 5. However, when the evaluation system according to the present invention includes a temperature measurement device, the path by which the server device obtains the measured temperature value is not limited. For example, the temperature measurement device and the server device may be configured to be able to communicate directly with each other.

[0087] In the above embodiment, the correction function is described as an example of a configuration in which correction is performed taking into account the state of the device, the temperature of the location to be evaluated, the ambient temperature, and the voltage generated in the transmitter coil 21. However, the form of correction in the present invention is not limited as long as it is performed based on the state of the device and the temperature of the location to be evaluated. In other words, the ambient temperature and the voltage generated in the transmitter coil are elements that are independently and arbitrarily considered in the correction in the present invention. Furthermore, elements other than those exemplified in the above embodiment may be considered in the correction.

[0088] In the above embodiment, when the state of the device is in a transition state, the correction value τ c is set to 0. However, in the present invention, the value to which the duration is converted when the state of the device is in a transition state is not limited to 0 as long as it satisfies a predetermined condition. Here, the value that satisfies the predetermined condition is preferably a value that satisfies the condition that it can be easily distinguished from the correction value when the state of the device is in an operating state or a stopped state (a value with a different digit, a value with a different sign, etc.).

[0089] In the above embodiment, an example has been described in which the operating state flag Fac and the stopped state flag Fst are determined based on the state of the device, and correction is implemented taking the state of the device into consideration. However, in the present invention, the method of taking the state of the device into consideration in correction is not limited. For example, instead of model formula (5) in the above embodiment, different model formulas may be used depending on the state of the device.

[0090] In the above embodiment, the operating state, in which the equipment is operating stably, is defined as a state in which the temperature of the evaluation location is stable in a high temperature range similar to the temperature of the fluid. The equipment is determined to be in an operating state when the average temperature of the evaluation location during a single measurement is higher than a predetermined threshold and the absolute value of the temperature change at the evaluation location during a single measurement is smaller than a predetermined threshold. However, the definition and judgment criteria of the operating state in the present invention are not limited to the above example. Such definition and judgment criteria can be determined taking into account the normal operating conditions of the equipment being evaluated and the temperature behavior under those conditions. For example, when evaluating equipment whose temperature fluctuates during normal operation, it is not appropriate to determine the stable state simply by the temperature being stable at a constant level, as in the above example. It is more appropriate to determine whether the equipment is in a stable state based on a temperature gradient, etc. The above points also apply to the definition and judgment criteria of the stopped state.

[0091] In the above embodiment, the representative values ​​of the duration τ, voltage, temperature, and time are transmitted to the server device 5, and the state identification function and the correction function are realized using these representative values. However, in the present invention, it is optional whether or not to identify the feature amount of each numerical value used in the calculation.

[0092] In the above embodiment, the evaluation system 1 includes one pulse eddy current probe 2, one temperature measuring device 3, one probe control device 4, and one server device 5. However, the present invention does not limit the number of each component. For example, multiple pulse eddy current probes may be connected to one probe control device. Furthermore, one server device may be configured to be able to communicate with multiple probe control devices.

[0093] Regarding other configurations, it should be understood that the embodiments disclosed in this specification are illustrative in all respects and that the scope of the present invention is not limited thereby. Those skilled in the art will easily understand that appropriate modifications are possible without departing from the spirit of the present invention. Therefore, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention. [Industrial Applicability]

[0094] The present invention can be used to grasp, for example, the transition of the wall thickness of a pipe. [Explanation of symbols]

[0095] 1: Rating system 2: Pulsed eddy current probe 21: Transmitting coil 22: Receiving coil 23: Microcontroller 3:Temperature measuring device 4: Probe control device 5: Server device N: Network T: Piping P: Pump

Claims

1. a pulsed eddy current probe having a transmitting coil and a receiving coil; at least one probe control device for controlling the pulsed eddy current probe; a server device capable of communicating with the probe control device, An evaluation system for evaluating an evaluation target portion to which the pulse eddy current probe is attached, The probe control device a calculation function for calculating a duration of an induced current generated in the receiving coil by being induced by a pulse current flowing in the transmitting coil; a transmission function of transmitting the duration to the server device, The server device: a state identification function for identifying a state of equipment including the evaluation target location based on the temperature of the evaluation target location; a correction function that corrects the duration received from the probe control device based on the state of the equipment identified by the state identification function and the temperature of the location to be evaluated to obtain a corrected value.

2. Further provided is a temperature measuring device for measuring the temperature of the evaluation target location, The evaluation system according to claim 1 , wherein the server device, in the state identification function, identifies the state of the equipment based on the temperature of the evaluation target location measured by the temperature measuring device.

3. The probe control device It is possible to further realize an acquisition function for acquiring the temperature of the evaluation target location measured by the temperature measurement device, and the transmission function transmits the duration and the temperature of the evaluation target location to the server device; The evaluation system according to claim 2 , wherein the server device, in the state specifying function, specifies the operating state of the equipment based on the temperature of the evaluation target location received from the probe control device.

4. The evaluation system according to any one of claims 1 to 3, wherein the server device, in the correction function, corrects the duration based on the state of the equipment identified in the state identification function, the temperature of the evaluation location, and the ambient temperature of the evaluation location.

5. The evaluation system according to any one of claims 1 to 3, wherein the server device, in the correction function, corrects the duration based on the state of the equipment identified in the state identification function, the temperature of the evaluation target location, and the voltage generated in the transmitting coil.

6. The server device: In the state specification function, the state of the equipment is specified as An operating state in which the equipment is operating stably; A stopped state in which the equipment is stopped stably, and A transition state that is a state during the period from when the operation of the equipment in the operating state is terminated to when the equipment is in the stopped state, or from when the operation of the equipment in the stopped state is started to when the equipment is in the operating state; The evaluation system according to any one of claims 1 to 3, selected from the group consisting of:

7. 7. The evaluation system according to claim 6, wherein when the server device determines in the state identification function that the equipment is in the transition state, the correction function performs a correction to convert the duration received from the probe control device into a value that satisfies a predetermined condition.

8. 1. An evaluation method for evaluating an evaluation target location to which a pulsed eddy current probe having a transmitting coil and a receiving coil is attached, using the pulsed eddy current probe, comprising: a calculation step of calculating a duration of an induced current generated in the receiving coil by being induced by the pulse current flowing in the transmitting coil; a state identification step of identifying a state of equipment including the evaluation target location based on the temperature of the evaluation target location; a correction step of correcting the duration calculated in the calculation step based on the state of the equipment identified in the state identification step and the temperature of the location to be evaluated to obtain a corrected value.

9. further comprising an evaluation step of evaluating the evaluation target portion based on the correction value; In the state specifying step, the state of the equipment is An operating state in which the equipment is operating stably; A stopped state in which the equipment is stopped stably, and A transition state that is a state during the period from when the operation of the equipment in the operating state is terminated to when the equipment is in the stopped state, or from when the operation of the equipment in the stopped state is started to when the equipment is in the operating state; selected from the group consisting of The evaluation method according to claim 8, wherein in the evaluation step, the correction value of the duration acquired at a time when the state of the equipment is identified as being in the transition state in the state identification step is excluded from the correction value used for evaluation.

10. An evaluation program executed in a computing device capable of communicating with a pulsed eddy current probe having a transmitting coil and a receiving coil, for evaluating an evaluation target portion to which the pulsed eddy current probe is attached, When executed on the computing device, a calculation function for calculating a duration of an induced current generated in the receiving coil by being induced by a pulse current flowing in the transmitting coil; a state identification function for identifying a state of equipment including the evaluation target location based on the temperature of the evaluation target location; and a correction function that corrects the duration calculated by the calculation function based on the operating state identified by the state identification function and the temperature of the location to be evaluated to obtain a corrected value.

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