Valve wall-thickness thinning prediction system and valve wall-thickness thinning prediction method

Abstract

To predict local thickness reduction inside a valve for appropriately maintaining the valve.SOLUTION: A prediction system for valve thickness reduction comprises: a measured value storage unit 101 storing at least one measurement data obtained by measurement performed by a fluid state sensor installed either on an upstream side or on a downstream side of the valve; a flow volume characteristic storage unit 102 storing a valve flow volume computational expression calculating a flow volume of the fluid passing inside the valve; an inlet / outlet flow condition estimation unit 103 which estimates and outputs a valve inlet / outlet flow condition with respect to at least one valve opening position; an inlet / outlet flow condition storage unit 104 storing the valve inlet / outlet flow condition; a thickness reduction speed database storage unit 105 which stores a thickness reduction speed distribution for each small area on an inner wall surface of the valve with respect to the valve inlet / outlet flow condition; a thickness reduction amount evaluation unit 106 which calculates and outputs an accumulative thickness reduction quantity distribution for each small area with respect to the valve opening position; and a thickness reduction quantity storage unit 107 storing an accumulative thickness reduction quantity distribution for each small area with respect to the valve opening position.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a valve wall thinning prediction system and a valve wall thinning prediction method. [Background technology]

[0002] It is important to predict changes in the flow characteristics and mechanical deterioration of valves used in piping within a plant and to replace valves and piping at the appropriate time.

[0003] Patent Document 1 discloses a control valve diagnostic device that provides a control valve located midway through a pipe through which a liquid flows with an opening indicator that detects the valve opening and a vibration accelerometer that detects vibration values, and a differential pressure meter that measures the valve pressure difference between the upstream and downstream sides of the control valve, diagnoses liquid leakage when the valve is closed based on the valve opening measured by the opening indicator and the vibration value measured by the vibration accelerometer, calculates a cavitation coefficient based on the valve pressure difference, and comprehensively evaluates the cavitation coefficient, vibration value, and valve opening value to determine whether or not there is mechanical deterioration during operation.

[0004] Patent Document 2 discloses a method for providing wall-thickness thinning prediction information, in which wall-thickness data of piping components that specifies the wall thickness of the piping components is received from a customer, and wall-thickness data of piping components that is simulated based on the received wall-thickness data is provided to the customer.The method involves computer-simulating the behavior of fluid flowing inside a piping line based on the wall-thickness data of the piping components and three-dimensional layout data of the piping line that includes the piping components, and determining the wall-thickness data of the piping components that make up the piping line from changes in the behavior of the simulated fluid.

[0005] Non-Patent Document 1 describes a simple method for predicting wall thinning, including the processes of fluid analysis, droplet trajectory analysis, and wall thinning evaluation. It describes that by applying the method for predicting wall thinning to a full-scale globe valve, the peak positions of the wall thinning rate correspond to the locations of holes in the actual valve, making it possible to predict the locations of wall thinning. It also describes that, as a result of using this method to evaluate the distribution of wall thinning rates by changing the valve opening, the locations of wall thinning may change significantly depending on the valve opening. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 6-94160 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-344295 [Non-patent literature]

[0007] [Non-Patent Document 1] Junya Watanabe et al., "Numerical Simulation of Droplet Impact Erosion in a Valve," Multiphase Flow, 2021, Vol. 35, No. 1, pp. 60-67 Summary of the Invention [Problem to be solved by the invention]

[0008] Generally, the internal shape of a valve is a complex three-dimensional shape. When a fluid flows through such a valve, separation and drift occur. As a result, high flow velocities and high pressures occur in certain parts of the valve flow area.

[0009] One indicator of the degree of valve deterioration is the amount of thinning on the valve's inner wall. When diagnosing thinning on the valve's inner wall, if the local flow inside the valve is not taken into account, thinning in areas where high flow velocity or high pressure occurs may be underestimated. If thinning progresses locally on the valve's inner wall, it may lead to unexpected damage such as holes or accidents.

[0010] In the control valve diagnostic device described in Patent Document 1, when the fluid flowing inside the control valve is liquid, the cavitation coefficient is calculated based on the valve differential pressure. Therefore, when dealing with cavitation problems under conditions where steam flows inside the valve and some of it condenses, there is room for improvement due to the difficulty of calculations using differential pressure and the different mechanisms of wall thinning. Furthermore, Patent Document 1 does not mention simulations using data on the internal shape of the valve.

[0011] Furthermore, in the method for providing wall-thinning prediction information described in Patent Document 2, the simulation is performed on the assumption that the internal shape of the piping component has a circular cross section. Therefore, the simulation does not take into account the complex internal shape of the valve, and does not take cavitation into consideration.

[0012] The condition of the fluid inside the valve changes depending on the usage status of the plant. Also, when a fluid flows through the valve, the shape of the flow path area formed inside the valve changes depending on the valve opening.

[0013] The present disclosure aims to accurately predict local wall thinning inside a valve in order to perform appropriate maintenance of the valve. [Means for solving the problem]

[0014] a valve wall thinning prediction system according to the present disclosure, which comprises a measurement value storage unit for storing at least one measurement data measured by a fluid state sensor installed on at least one of the upstream and downstream sides of the valve; a flow characteristics storage unit for storing a valve flow rate calculation formula for calculating the flow rate of a fluid passing through the inside of the valve; an inlet / outlet flow condition estimation unit for estimating and outputting a valve inlet / outlet flow condition for at least one valve opening; an inlet / outlet flow condition storage unit for storing the valve inlet / outlet flow conditions; a wall thinning rate database storage unit for storing the wall thinning rate distribution of each small region on the inner wall surface of the valve for the valve inlet / outlet flow conditions; a wall thinning amount evaluation unit for calculating and outputting the cumulative wall thinning amount distribution of each small region for the valve opening; and a wall thinning amount storage unit for storing the cumulative wall thinning amount distribution of each small region for the valve opening, and which predicts wall thinning of a valve.

[0015] Furthermore, the valve wall thinning prediction method according to the present disclosure stores at least one piece of measurement data measured by a fluid state sensor installed on at least one of the upstream and downstream sides of the valve in a measurement value storage unit, stores a valve flow rate calculation formula for calculating the flow rate of fluid passing through the inside of the valve in a flow characteristics storage unit, estimates valve inlet and outlet flow conditions for at least one valve opening, stores the valve inlet and outlet flow conditions in an inlet and outlet flow condition storage unit, stores the wall thinning rate distribution for each small region on the inner wall surface of the valve for the valve inlet and outlet flow conditions in a wall thinning rate database storage unit, calculates the cumulative wall thinning amount distribution for each small region for the valve opening in a wall thinning amount evaluation unit, and predicts valve wall thinning. [Effects of the Invention]

[0016] According to the present disclosure, by using at least one measurement value, the flow path area inside the valve can be divided into multiple small areas, and by taking into account the local flow inside the valve, thinning of the inner wall of the valve can be predicted for each small area, allowing for appropriate maintenance of the valve. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a configuration diagram showing a metal-thickness thinning prediction system according to a first embodiment. FIG. [Figure 2] This figure shows a specific example of the contents of the valve inlet and outlet flow conditions. [Figure 3] 2 is a diagram showing a specific example of data stored in an inlet / outlet flow condition storage unit 104 of FIG. 1. FIG. [Figure 4] FIG. 10 is a diagram showing a specific example of the contents of the wall-thinning rate distribution. [Figure 5] FIG. 10 is a diagram showing a specific example of the content of the cumulative wall-thinning amount distribution. [Figure 6] 2 is a diagram showing a specific example of data stored in a wall-thinning amount storage unit 107 in FIG. 1. FIG. [Figure 7] FIG. 10 is a diagram illustrating an example of an image on a display device. [Figure 8] FIG. 1 is a flowchart showing a method for predicting metal-thinning according to a first embodiment. [Figure 9]FIG. 2 is a flowchart showing the process of estimating flow conditions at the inlet and outlet of a valve when one type of measurement data is stored in the measurement value storage unit 101 of FIG. 1. [Figure 10] FIG. 2 is a flowchart showing the process of estimating valve inlet and outlet flow conditions when two types of measurement data including a valve inlet fluid pressure are stored in the measurement value storage unit 101 of FIG. 1. [Figure 11] FIG. 10 is a configuration diagram showing a wall-thinning prediction system according to a second embodiment. [Figure 12] FIG. 10 is a diagram showing an example of an image on a display device according to a second embodiment. [Figure 13] FIG. 10 is a flowchart showing a method for predicting metal-thinning according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] Embodiments of the present disclosure will be described below with reference to the drawings. In each embodiment, at least one measurement value is used to divide the flow path area inside the valve into multiple small areas, and local flow inside the valve is taken into account to predict thinning of the valve's inner wall for each small area. Note that common components in the following figures will be assigned the same reference numerals and redundant explanations will be omitted.

[0019] First Embodiment The first embodiment is an embodiment in which thinning of a valve is predicted without detecting the valve opening.

[0020] FIG. 1 is a configuration diagram showing a wall-thinning prediction system according to this embodiment.

[0021] As shown in this figure, the metal thinning prediction system 100 (valve metal thinning prediction system) includes a measurement value storage unit 101, a flow characteristic storage unit 102, an inlet / outlet flow condition estimation unit 103, an inlet / outlet flow condition storage unit 104, a metal thinning rate database storage unit 105, a metal thinning amount evaluation unit 106, a metal thinning amount storage unit 107, and a display unit 108.

[0022] The metal thinning prediction system 100 is a system that predicts thinning of valve walls. Thinning occurs on the inner walls of valves that come into contact with fluids due to erosion, corrosion, and the like. When two-phase fluids such as wet steam flow through the valve, cavitation erosion and liquid droplet impingement (LDI) progress. The metal thinning prediction system 100 calculates the rate and amount of thinning of the inner walls of the valve to enable quantitative evaluation of such thinning.

[0023] The metal-thinning prediction system 100 is configured by a computer equipped with, for example, an arithmetic unit such as a CPU (Central Processing Unit), a storage device such as a ROM (Read Only Memory) and a RAM (Random Access Memory), an external storage device such as a magnetic disk, an optical disk, and a nonvolatile memory, an input interface (input unit), an output interface (output unit), a transmission / reception function, etc. Some of the functions of the metal-thinning prediction system 100 may be executed by a program recorded on a computer-readable recording medium or by other hardware.

[0024] The measurement value storage unit 101 stores, as measurement data, the state quantities of the fluid measured by a sensor (fluid state sensor) installed at least on the upstream side or downstream side of the valve. Specifically, the measurement data is any one of the valve inlet fluid pressure, valve inlet fluid temperature, valve outlet fluid pressure, valve outlet fluid temperature, and the flow rate of the fluid passing through the valve. The measurement value storage unit 101 stores at least one piece of measurement data. In this specification, "storing" refers to recording data, programs, etc. in a computer-readable recording medium, storage device, etc.

[0025] The flow rate characteristics storage unit 102 stores a valve flow rate calculation formula for calculating the flow rate of a fluid passing through a valve from the valve inlet fluid pressure, the valve outlet fluid pressure, and the valve opening.

[0026] Specifically, the valve flow rate calculation formula is defined by the following formulas (1) and (2).

[0027]

number

[0028]

number

[0029] where G is the flow rate of the fluid passing through the valve, P1 is the fluid pressure at the valve inlet, P2 is the fluid pressure at the valve outlet, and V A is the valve opening, C v is the flow coefficient, and α is the critical pressure ratio. v (V A ) is the valve opening V A is used as a variable to calculate the flow coefficient C v This shows that the following can be obtained.

[0030] Next, the relationship between the valve inlet fluid pressure P1, the valve outlet fluid pressure P2, and the flow rate G of the fluid passing through the valve will be described.

[0031] When P1 and P2 are equal, that is, when the pressure ratio P2 / P1 = 1, no flow occurs inside the valve, so G = 0. As P2 / P1 decreases from 1 and the difference between P1 and P2 increases, the flow velocity inside the valve increases and G increases. In this case, G is calculated using the above formula (1).

[0032] When P2 / P1 decreases to the critical pressure ratio α, the flow velocity becomes equal to the speed of sound, and even if P2 / P1 decreases below α, the flow velocity does not become faster than the speed of sound. In other words, when P2 / P1<α, the flow velocity is always equal to the speed of sound, and in this case, G is calculated using the above formula (2).

[0033] The inlet / outlet flow condition estimation unit 103 receives the measurement data stored in the measurement value storage unit 101 and the valve flow rate calculation formula stored in the flow rate characteristics storage unit 102 as input, estimates the valve inlet / outlet flow conditions for one or more valve openings, and outputs them.

[0034] Figure 2 shows a specific example of the contents of the valve inlet and outlet flow conditions.

[0035] In this figure, the valve inlet / outlet flow conditions 110 are composed of the valve opening, valve inlet flow velocity, valve inlet fluid temperature, and valve outlet fluid pressure required to determine the flow in the valve.

[0036] The inlet / outlet flow condition storage unit 104 (FIG. 1) stores the valve inlet / outlet flow condition for at least one valve opening estimated and output by the inlet / outlet flow condition estimation unit 103.

[0037] FIG. 3 is a diagram showing a specific example of data stored in the inlet / outlet flow condition storage unit 104 of FIG.

[0038] In FIG. 3, valve inlet / outlet flow conditions 110 for a valve opening of 100% and a valve opening of 20% are stored.

[0039] The wall thinning rate database storage unit 105 (FIG. 1) stores a plurality of wall thinning rate distributions on the inner wall surface of the valve for the valve inlet / outlet flow conditions 110.

[0040] FIG. 4 is a diagram showing a specific example of the contents of the wall-thinning rate distribution.

[0041] In this figure, a metal thinning rate distribution 111 is made up of valve inlet / outlet flow conditions 110 and a region ID / coordinate / metal thinning rate table 112 for each small region of the valve inner wall (inner wall surface of the valve) for the flow inside the valve calculated from the valve inlet / outlet flow conditions 110. Here, for example, the region ID "7" is assigned to "small region 7."

[0042] Here, the flow path area inside the valve is divided into multiple small areas based on the valve shape information, material information, and valve inlet / outlet flow conditions 110, and a numerical analysis simulation is performed that takes into account the local flow inside the valve, and a table of area IDs, coordinates, and wall thinning rates for each small area is created 112. Note that while it is desirable to calculate and store data obtained by simulation in advance as a database, it is also possible to perform the simulation in real time and obtain the data.

[0043] The metal-thinning amount evaluation unit 106 (FIG. 1) receives as input a valve inlet / outlet flow condition 110 for at least one valve opening stored in the inlet / outlet flow condition storage unit 104 and a metal-thinning rate distribution 111 stored in the metal-thinning rate database storage unit 105, and calculates and outputs the cumulative metal-thinning amount distribution for each small region of the valve inner wall for at least one valve opening.

[0044] FIG. 5 is a diagram showing a specific example of the content of the cumulative wall-thinning amount distribution.

[0045] In this figure, the cumulative wall-thinning distribution 113 is composed of the valve opening and a table of region IDs, coordinates, and cumulative wall-thinning amounts for each small region on the valve inner wall relative to the valve opening. The cumulative wall-thinning distribution 113 shows the cumulative wall-thinning distribution for each small region on the valve inner wall under the condition that the valve opening does not change over time and is maintained.

[0046] The wall-thinning amount storage unit 107 (FIG. 1) stores the cumulative wall-thinning amount distribution for at least one valve opening.

[0047] FIG. 6 is a diagram showing a specific example of data stored in the wall-thickness reduction amount storage unit 107 of FIG.

[0048] In FIG. 6, the cumulative wall-thinning amount distribution 113 for a valve opening of 100% and a valve opening of 20% is stored.

[0049] Display unit 108 (FIG. 1) has a display device. Examples of the display device include a liquid crystal display, a plasma display, an organic EL display, a cathode ray tube, etc. Display unit 108 receives accumulated wall-thinning amount distribution 113 for at least one valve opening stored in wall-thinning amount storage unit 107 as input, and outputs accumulated wall-thinning amount distribution for each small region of the valve inner wall for each valve opening.

[0050] FIG. 7 is a diagram showing an example of an image displayed on the display device.

[0051] In this figure, a numerical image 114 and a shape image 115 are displayed on the display device 120. The numerical image 114 is the cumulative amount of thinning collected for each small area of ​​the valve's inner wall for each valve opening. The shape image 115 is the shape of the flow path area or inner wall of the valve 1.

[0052] The numerical image 114 can be displayed as a table or the like in association with an identifier (area ID) or coordinates assigned to each small area of ​​the valve's inner wall. The shape image 115 can be displayed two-dimensionally or three-dimensionally in association with the cumulative amount of thinning for each small area of ​​the valve's inner wall. The shape image 115 can be created using image software or the like that models numerical data.

[0053] As shown in Fig. 7, the identifiers (area IDs) displayed on the table can also be displayed in the corresponding areas of the shape image 115. Areas where the accumulated wall-thinning amount is greater than a predetermined threshold, locations where significant wall-thinning has occurred, and the risk of wall-thinning for each cell can be visually highlighted by coloring, texture, etc. Also, a map can be displayed with each cell differentiated by color or texture for each numerical range of the accumulated wall-thinning amount.

[0054] Alternatively, unlike Fig. 7, in the initial display, it is possible to display only the shape image 115 without displaying the numerical value image 114. In this initial display state, when an arbitrary cell on the shape image 115 is designated by clicking or the like, the coordinates of the cell, the accumulated amount of thinning, etc. can be displayed in a pop-up or the like.

[0055] Next, the process of predicting valve wall thinning by the wall thinning prediction system 100 will be described in detail.

[0056] FIG. 8 is a flowchart showing a method for predicting wall-thickness reduction (valve wall-thickness reduction prediction method) according to this embodiment.

[0057] In this diagram, first, in step S151 (valve opening input step), at least one valve opening for predicting valve thinning is input from the input unit of the metal thinning prediction system 100. As a specific example, two valve openings are input: 100%, which is the maximum valve opening, and 20%, which is the minimum valve opening. Alternatively, three valve openings are input: 100% and 20%, which are the maximum and minimum valve openings, and 50%, which is an intermediate valve opening. The valve opening is usually input by a user, but the valve opening determined by another automatic device, for example, by detecting the passage of a predetermined time or by some kind of calculation, may be input to the input unit as an electrical signal.

[0058] In step S152 (measurement value acquisition step), the measurement value storage unit 101 acquires and stores measurement data measured by a sensor installed on at least one of the upstream side and downstream side of the valve.

[0059] In step S153 (inlet / outlet flow condition estimation step), the inlet / outlet flow condition estimation unit 103 receives the measurement data stored in the measurement value storage unit 101 and the valve flow rate calculation formula stored in the flow characteristics storage unit 102, and estimates the valve inlet / outlet flow conditions 110 for the valve opening. The inlet / outlet flow condition storage unit 104 stores the valve inlet / outlet flow conditions 110.

[0060] In step S154 (metal thinning rate acquisition step), the metal thinning amount evaluation unit 106 receives as input the valve inlet / outlet flow conditions 110 stored in the inlet / outlet flow condition storage unit 104 and the metal thinning rate distribution 111 stored in the metal thinning rate database storage unit 105, and selects one appropriate metal thinning rate distribution 111 from the multiple metal thinning rate distributions 111. This selection process is performed by selecting the valve inlet / outlet flow conditions 110 stored in the inlet / outlet flow condition storage unit 104 and the valve inlet / outlet flow conditions 110 described in the metal thinning rate distribution 111 that match. If no matching conditions exist, the closest conditions are selected.

[0061] In step S155 (metal-thinning rate integration step), the metal-thinning amount evaluation unit 106 receives the metal-thinning rate distribution 111 selected in step S154 as an input, time-integrates the metal-thinning rate for each small region of the inner wall of the valve at the current time, and calculates the amount of change in metal-thinning for each small region of the inner wall of the valve at the current time.

[0062] In step S156 (cumulative wall-thinning amount calculation process), the wall-thinning amount evaluation unit 106 reads the cumulative wall-thinning amount distribution 113 from the wall-thinning amount storage unit 107, and adds the change in wall-thinning amount for each small area of ​​the valve at the current time calculated in step S155 to the cumulative wall-thinning amount for each small area of ​​the inner wall of the valve up to the previous measurement time included in the cumulative wall-thinning amount distribution 113 to calculate the cumulative wall-thinning amount for each small area of ​​the inner wall of the valve up to the current time, updates the cumulative wall-thinning amount distribution 113, and outputs it to the wall-thinning amount storage unit 107.

[0063] In step S157 (accumulated wall-thinning amount calculation completion determination step), the wall-thinning amount evaluation unit 106 determines whether the accumulated wall-thinning amount distribution 113 has been updated for all valve openings input in step S151. If the determination result is YES, the process proceeds to step S158 (display step), and if NO, the process proceeds to step S153 (inlet / outlet flow condition estimation step), and the subsequent processes are repeated.

[0064] In step S158 (display step), the display unit 108 receives the cumulative wall-thinning amount distribution 113 for at least one valve opening stored in the wall-thinning amount storage unit 107 as input, and displays the cumulative wall-thinning amount distribution for each small region of the valve inner wall for each valve opening on the display device 120.

[0065] In step S159 (metallurgy reduction prediction process end determination step), the metallurgy reduction prediction system 100 determines whether the process for predicting metallurgy reduction has reached the end time. If the determination result is NO, the process proceeds to step S152 (measurement value acquisition step) and the subsequent processes are repeated. On the other hand, if the determination result is YES, the process for predicting valve metallurgy reduction is ended.

[0066] Next, the process of estimating the valve inlet / outlet flow conditions by the inlet / outlet flow condition estimating unit 103 will be described in detail.

[0067] FIG. 9 is a flowchart showing the process of estimating the flow conditions at the inlet and outlet of a valve when one type of measurement data is stored in the measurement value storage unit 101 of FIG.

[0068] 9, first, in step S161 (valve inlet pressure storage determination step), it is determined whether or not the valve inlet fluid pressure P1 is stored in the measurement value storage unit 101. If the determination result is YES, the process proceeds to step S162 (valve inlet temperature estimation step), and if the determination result is NO, the process proceeds to step S166 (valve inlet temperature storage determination step).

[0069] In step S162 (valve inlet temperature estimation step), the valve inlet fluid pressure P1 is input and the valve inlet fluid temperature T1 is estimated. Specifically, assuming that the fluid flowing into the valve is saturated, the saturation temperature T sat Calculate T1 and T sat This is inferred from the fact that it is equal to

[0070] In step S163 (valve outlet pressure estimation step), P1 is used as an input to estimate valve outlet fluid pressure P2. Specifically, assuming that P2 / P1 is equal to the critical pressure ratio α, P2 is estimated from the fact that it is equal to α×P1.

[0071] In step S164 (valve passage flow rate calculation step), the valve opening V A , P1, and P2 are used as inputs, and the flow rate G of the fluid passing through the valve is calculated using the above formula (1).

[0072] In step S165 (valve inlet flow velocity calculation step), the valve inlet flow velocity u1 is calculated using P1, T1, and G. Specifically, the valve inlet fluid density ρ1 is calculated from P1 and T1, and u1 is calculated using the following formula (3).

[0073]

number

[0074] where A is the cross-sectional area of ​​the flow passage at the valve inlet.

[0075] In step S166 (valve inlet temperature storage determination step), it is determined whether or not the valve inlet fluid temperature T1 is stored in the measurement value storage unit 101. If the determination result is YES, the process proceeds to step S167 (valve inlet pressure estimation step), and if the determination result is NO, the process proceeds to step S168 (valve outlet pressure storage determination step).

[0076] In step S167 (valve inlet pressure estimation step), T1 is used as an input to estimate P1. Specifically, assuming that the fluid flowing into the valve is saturated, the saturated pressure P sat Calculate P1 and P sat After step S167 is executed, the process proceeds to step S163.

[0077] In step S168 (valve outlet pressure storage determination step), it is determined whether or not the valve outlet pressure P2 is stored in the measurement value storage unit 101. If the determination result is YES, the process proceeds to step S169 (valve inlet pressure estimation step), and if the determination result is NO, the process proceeds to step S171 (valve outlet temperature storage determination step).

[0078] In step S169 (valve inlet pressure estimation step), P2 is input and P1 is estimated. Specifically, assuming that P2 / P1 is equal to the critical pressure ratio α, P1 is estimated from the fact that it is equal to P2 / α.

[0079] In step S170 (valve inlet temperature estimation step), P1 is input and T1 is estimated. The specific processing content is the same as that of step S162, so a description thereof will be omitted. After step S170 is executed, the process proceeds to step S164.

[0080] In step S171 (valve outlet temperature storage determination step), it is determined whether or not the valve outlet fluid temperature T2 is stored in the measurement value storage unit 101. If the determination result is YES, the process proceeds to step S172 (valve outlet pressure estimation step), and if the determination result is NO, the process proceeds to step S173 (valve inlet pressure estimation step).

[0081] In step S172 (valve outlet pressure estimation step), T2 is input and P2 is estimated. Specifically, assuming that the fluid flowing out of the valve is saturated, the saturation pressure P sat Calculate P2 and P sat After step S172 is executed, the process proceeds to step S169.

[0082] In step S173 (valve inlet pressure estimation process), V A , G are used as inputs to estimate P1. Specifically, assuming that P2 / P1 is equal to the critical pressure ratio α, P1 is calculated using the following equation (4), which is a modification of the above equation (2).

[0083]

number

[0084] In step S174 (valve inlet temperature estimation step), P1 is input and T1 is estimated. The specific processing content is the same as in step S162, so a description thereof will be omitted.

[0085] In step S175 (valve outlet pressure estimation step), P1 is input and P2 is estimated. The specific processing content is the same as that of step S163, so the explanation will be omitted. After step S175 is executed, the process proceeds to step S165.

[0086] By the processing of steps S161 to S175, when one piece of measurement data is stored in the measurement value storage unit 101, the valve opening V required to determine the flow in the valve is calculated. A After estimating all of the valve inlet flow velocity u1, valve inlet fluid temperature T1, and valve outlet fluid pressure P2, the process of estimating the valve inlet and outlet flow conditions is terminated.

[0087] FIG. 10 is a flowchart showing the process of estimating the valve inlet and outlet flow conditions when two types of measurement data including the valve inlet fluid pressure are stored in the measurement value storage unit 101 of FIG.

[0088] 10, first, in step S181 (valve outlet pressure storage determination step), it is determined whether P1 and P2 are stored in the measurement value storage unit 101. If the determination result is YES, the process proceeds to step S182 (valve inlet temperature estimation step), and if the determination result is NO, the process proceeds to step S185 (valve outlet temperature storage determination step).

[0089] In step S182 (valve inlet temperature estimation step), P1 is input and T1 is estimated. The specific processing content is the same as that of step S162, so a description thereof will be omitted.

[0090] In step S183 (valve passing flow rate calculation process), V A, P1, P2 are input to calculate G. Specifically, if P2 / P1 is equal to or greater than α, G is calculated using the above formula (1), and if P2 / P1 is smaller than α, G is calculated using the above formula (2).

[0091] In step S184 (valve inlet flow velocity calculation step), the valve inlet flow velocity u1 is calculated using P1, T1, and G. The specific processing content is the same as in step S165, and therefore description thereof will be omitted.

[0092] In step S185 (valve outlet temperature storage determination step), it is determined whether P1 and T2 are stored in the measurement value storage unit 101. If the determination result is YES, the process proceeds to step S186 (valve outlet pressure estimation step), and if the determination result is NO, the process proceeds to step S187 (valve inlet temperature storage determination step).

[0093] In step S186 (valve outlet pressure estimation step), T2 is input and P2 is estimated. The specific processing content is the same as that of step S172, so a description thereof will be omitted. After step S186 is executed, the process proceeds to step S182.

[0094] In step S187 (valve inlet temperature storage determination step), it is determined whether P1 and T1 are stored in the measurement value storage unit 101. If the determination result is YES, the process proceeds to step S188 (valve outlet pressure estimation step), and if the determination result is NO, the process proceeds to step S189 (valve outlet pressure calculation step).

[0095] In step S188 (valve outlet pressure estimation step), P1 is input and P2 is estimated. The specific processing content is the same as that of step S163, so the explanation will be omitted. After step S188 is executed, the process proceeds to step S183.

[0096] In step S189 (valve outlet pressure calculation process), V A , P1, and G are input, and P2 is calculated. Specifically, first, P2 is calculated from the following equation (5), which is a modification of the above equation (1).

[0097]

number

[0098] If P2 / P1 is equal to or greater than α, the application condition of the above formula (1) (P2 / P1≧α) is satisfied, so P2 calculated using the above formula (5) is used. If P2 / P1 is less than α, the application condition of the above formula (1) is not satisfied, so P2 is calculated by assuming that P2 / P1 is equal to α and P2 is equal to α×P1.

[0099] In step S190 (valve inlet temperature estimation step), P1 is input and T1 is estimated. The specific processing content is the same as that of step S162, so a description thereof will be omitted. After step S190 is executed, the process proceeds to step S184.

[0100] By the processing of steps S181 to S190, when two measurement data including the valve inlet fluid pressure are stored, the valve opening V required to determine the flow in the valve is calculated. A After estimating all of the valve inlet flow velocity u1, valve inlet fluid temperature T1, and valve outlet fluid pressure P2, the process of estimating the valve inlet and outlet flow conditions is terminated.

[0101] Even when two measurement data excluding the valve inlet fluid pressure are stored, or when more than two measurement data are stored, the valve inlet / outlet flow conditions can be estimated by processing similar to that shown in Figure 9 or Figure 10, and detailed explanations will be omitted.

[0102] In this embodiment, at least one valve opening is specified, and at least one measurement value is used to estimate the flow conditions at the valve inlet and outlet for the specified valve opening. Furthermore, based on the estimated flow conditions at the valve inlet and outlet, the flow path area inside the valve is divided into multiple small regions, and the local flow inside the valve is taken into account to calculate the cumulative wall thinning distribution of the valve for each small region. The cumulative wall thinning distribution is then displayed on the screen for each valve opening. In other words, if at least one measurement value is available, it is possible to predict the wall thinning of the valve for each small region.

[0103] Furthermore, in this embodiment, the specified valve opening does not change over time, and the thinning of the valve inner wall is predicted under conditions where the valve opening is maintained. Because the location where thinning occurs varies depending on the valve opening, a representative valve opening is specified at the start of prediction, and thinning of the valve inner wall is predicted for each valve opening under conditions where the valve opening is maintained. This makes it possible to comprehensively identify locations where thinning is likely to occur, and to predict thinning of the valve inner wall on the safe side.

[0104] As described above, in this embodiment, the flow path area inside the valve is divided into multiple small areas using at least one measurement value, and thinning of the valve inner wall can be predicted for each small area by taking into account the local flow inside the valve.

[0105] Second Embodiment The second embodiment is an embodiment of a wall-thinning prediction system capable of detecting a valve opening degree.

[0106] FIG. 11 is a configuration diagram showing a wall-thinning prediction system according to this embodiment.

[0107] This embodiment differs from the first embodiment in that, as shown in the figure, a valve opening storage unit 201 is added to a wall-thinning prediction system 200, an inlet / outlet flow condition estimation unit 203 is provided instead of the inlet / outlet flow condition estimation unit 103, and a display unit 208 is provided instead of the display unit 108.

[0108] Valve openings acquired by sensors installed in the valve bodies are stored in the valve opening storage unit 201. Examples of such sensors (valve opening sensors) include potentiometers, positioners, and pneumatic sensors.

[0109] The inlet / outlet flow condition estimation unit 203 receives the valve opening stored in the valve opening storage unit 201, the measurement data stored in the measurement value storage unit 101, and the valve flow rate calculation formula stored in the flow rate characteristics storage unit 102 as inputs, and estimates and outputs the valve inlet / outlet flow conditions for the valve opening stored in the valve opening storage unit 201.

[0110] The display unit 208 receives the cumulative wall-thinning amount distribution stored in the wall-thinning amount storage unit 107 as an input, and outputs the cumulative wall-thinning amount distribution for each small region of the valve inner wall.

[0111] FIG. 12 is a diagram showing an example of an image displayed on the display device.

[0112] In this figure, a numerical image 114 and a shape image 115 are displayed on the display device 120. The numerical image 114 is the cumulative amount of thinning collected for each small region of the inner wall of the valve. The shape image 115 is the shape of the flow path region or inner wall of the valve 1.

[0113] The above are the differences between this embodiment and the first embodiment, and other points are the same as those of the first embodiment.

[0114] Next, the process of predicting valve wall thinning by the wall thinning prediction system 200 will be described in detail.

[0115] FIG. 13 is a flowchart showing a method for predicting wall-thickness reduction (valve wall-thickness reduction prediction method) according to this embodiment.

[0116] This embodiment differs from the first embodiment in that it has processing steps of step S251 instead of step S151, step S253 instead of step S153, and step S258 instead of step S158. Step S157 is unnecessary and is not included in the processing steps.

[0117] In step S251 (valve opening degree acquisition step), the valve opening degree storage unit 201 stores the valve opening degree acquired by a sensor installed in the valve body.

[0118] In step S253 (inlet / outlet flow condition estimation step), the inlet / outlet flow condition estimation unit 203 receives as input the valve opening stored in the valve opening storage unit 201, the measurement data stored in the measurement value storage unit 101, and the valve flow rate calculation formula stored in the flow rate characteristics storage unit 102, and estimates the valve inlet / outlet flow condition 110 for the valve opening, and stores the result in the inlet / outlet flow condition storage unit 104.

[0119] In step S258 (display step), the display unit 208 receives the cumulative wall-thinning amount distribution 113 stored in the wall-thinning amount storage unit 107 and displays the cumulative wall-thinning amount distribution for each small region of the valve inner wall on the display device 120.

[0120] In this embodiment, the flow conditions at the valve inlet and outlet are estimated using the valve opening acquired by a sensor installed in the valve body and at least one measurement value. That is, in addition to the effects obtained in the first embodiment, this embodiment predicts thinning of the valve inner wall by taking into account the influence of the valve opening, making it possible to predict thinning of the valve inner wall with even higher accuracy.

[0121] In both the first and second embodiments, the valve may be either manually operated or automatically operated.

[0122] Furthermore, the content that is described above as being displayed on the display device does not necessarily have to be actually displayed. For example, instead of displaying it, an audio warning of wall thinning may be issued, or the user may be notified by visual or audio warning only when a valve or the like needs to be replaced or repaired. [Explanation of symbols]

[0123] 100, 200: metal thinning prediction system, 101: measurement value storage unit, 102: flow rate characteristics storage unit, 103, 203: inlet / outlet flow condition estimation unit, 104: inlet / outlet flow condition storage unit, 105: metal thinning rate database storage unit, 106: metal thinning amount evaluation unit, 107: metal thinning amount storage unit, 108, 208: display unit, 110: valve inlet / outlet flow condition, 111: metal thinning rate distribution, 112: area ID / coordinate / metal thinning rate table, 113: cumulative metal thinning amount distribution, 114: numerical image, 115: shape image, 120: display device, 201: valve opening storage unit.

Claims

1. a measurement value storage unit that stores at least one measurement data measured by a fluid state sensor installed on at least one of the upstream side and downstream side of the valve; a flow rate characteristics storage unit that stores a valve flow rate calculation formula for calculating the flow rate of a fluid passing through the inside of the valve; an inlet / outlet flow condition estimation unit that receives the measurement data stored in the measurement value storage unit and the valve flow rate calculation formula stored in the flow characteristic storage unit as inputs and estimates and outputs valve inlet / outlet flow conditions for at least one valve opening; an inlet / outlet flow condition storage unit for storing the valve inlet / outlet flow conditions; a thinning rate database storage unit that stores a thinning rate distribution for each small region of the inner wall surface of the valve with respect to the valve inlet / outlet flow conditions; a wall-thinning amount evaluation unit that receives as input the valve inlet / outlet flow conditions for the valve aperture stored in the inlet / outlet flow condition storage unit and the wall-thinning rate distribution stored in the wall-thinning rate database storage unit, calculates and outputs a cumulative wall-thinning amount distribution for each small region for the valve aperture; a thinning amount storage unit that stores the cumulative thinning amount distribution for each small region with respect to the valve opening degree, The valve flow rate calculation formula is defined by the following formulas (1) and (2): [Equation 1] [Equation 2] (In the formula, G represents the flow rate of the fluid passing through the valve, P 1 represents the fluid pressure at the valve inlet, P 2 represents the fluid pressure at the valve outlet, V A represents the valve opening, C v represents the flow coefficient, and α represents the critical pressure ratio. Also, C v (V A ) indicates that the flow coefficient C v can be determined using the valve opening V A as a variable.) A valve wall thinning prediction system that predicts wall thinning of the valve.

2. The valve wall-thinning prediction system according to claim 1 , further comprising a display unit that displays the cumulative wall-thinning amount distribution for each of the small regions with respect to the valve opening.

3. further comprising an input unit for inputting the valve opening degree; The valve wall thinning prediction system according to claim 1 , wherein the inlet / outlet flow condition estimation unit estimates the valve inlet / outlet flow conditions using the input valve opening.

4. a valve opening storage unit that stores the valve opening acquired by a valve opening sensor installed in the valve; The valve wall-thickness thinning prediction system according to claim 1 , wherein the inlet / outlet flow condition estimation unit estimates the valve inlet / outlet flow conditions using the acquired valve opening.

5. The valve wall thinning prediction system according to claim 1 , wherein the fluid state sensor measures a temperature or a pressure of the fluid.

6. storing at least one measurement data measured by a fluid state sensor installed on at least one of the upstream side and downstream side of the valve in a measurement value storage unit; a valve flow rate calculation formula for calculating the flow rate of a fluid passing through the inside of the valve is stored in a flow rate characteristics storage unit; an inlet / outlet flow condition estimation unit estimates valve inlet / outlet flow conditions for at least one valve opening using the measurement data stored in the measurement value storage unit and the valve flow rate calculation formula stored in the flow characteristic storage unit as inputs; storing the valve inlet / outlet flow conditions in an inlet / outlet flow condition storage unit; storing a wall thinning rate distribution for each small region of the inner wall surface of the valve corresponding to the valve inlet / outlet flow conditions in a wall thinning rate database storage unit; a metal-thinning amount evaluation unit receives as input the valve inlet / outlet flow conditions for the valve opening stored in the inlet / outlet flow condition storage unit and the metal-thinning rate distribution stored in the metal-thinning rate database storage unit, calculates a cumulative metal-thinning amount distribution for each small region for the valve opening, and predicts metal-thinning of the valve, The valve wall thinning prediction method, wherein the valve flow rate calculation formula is defined by the following formulas (1) and (2): [Equation 3] [Equation 4] (In the formula, G represents the flow rate of the fluid passing through the valve, P 1 represents the fluid pressure at the valve inlet, P 2 represents the fluid pressure at the valve outlet, V A represents the valve opening, C v represents the flow coefficient, and α represents the critical pressure ratio. Also, C v (V A ) indicates that the flow coefficient C v can be determined using the valve opening V A as a variable.)

7. The valve wall-thinning prediction method according to claim 6, further comprising the step of displaying the calculated cumulative wall-thinning amount distribution for each small region with respect to the valve opening on a display unit.

8. 7. The valve wall-thickness thinning prediction method according to claim 6, wherein the estimation of the inlet and outlet flow conditions is performed by using the valve opening input from an input unit.

9. 7. The valve wall-thinning prediction method according to claim 6, wherein the estimation of the inlet and outlet flow conditions is performed using the valve opening acquired by a valve opening sensor installed in the valve.

10. The valve wall thinning prediction method according to claim 6 , wherein the measurement data is a temperature or a pressure of the fluid.

Images