Valve maintenance support device and method

Abstract

To improve the work efficiency of maintenance of a bellows valve.SOLUTION: This valve maintenance assistance device comprises: a full-open data extraction unit 5 that searches for the data of an opening-degree command value that indicates fully open among opening-degree command values given to a bellows valve and extracts, as diagnosis data, the actual opening-degree of the bellows valve that is given this opening-degree command value and the actual opening-degree value in a time slot corresponding to the opening-degree command value that indicates fully open; a full-open failure assessment unit 6 for assessing, on the basis of the diagnosis data, whether or not there is occurrence of a full-open failure state in the bellows valve that is given the opening-degree command value that indicates fully open does not go to fully open; and an assessment result presentation unit 8 for presenting the ID of the bellows valve assessed as having a full-open failure state occurred as the ID of a valve to which bellows breakage has occurred.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technique for assisting maintenance work, and more particularly to a valve maintenance assistance device and method for assisting maintenance work on a bellows valve having a bellows-like bellows arranged to surround the outer periphery of a valve stem connected to a valve body. [Background technology]

[0002] Conventionally, valves used in petrochemical plants and the like (for example, the control valve in FIG. 10) require particular attention to safety, and therefore undergo regular maintenance. Valve 100 shown in FIG. 10 comprises a valve body 101, a positioner 102, and an actuator 103. The actuator 103 moves a valve stem 104 up and down in response to air pressure Po supplied from the positioner 102 to adjust the opening of the valve (the gap between the valve body 105 and the seat ring 106). In other words, it adjusts the flow of the fluid.

[0003] The positioner 102 detects the lift position of the valve shaft 104, i.e., the actual opening of the valve, from the rotational angle position of a feedback lever 107 connected to the valve shaft 104, and supplies an air pressure Po to the actuator 103 according to the difference between the detected actual opening and the set opening.

[0004] In this valve 100, a bellows-shaped bellows (bellows seal) 108 is provided on the outer periphery of a valve shaft 104 connected to a valve body 105 in order to prevent external leakage of fluid. The bellows 108 is made of a corrosion-resistant metal material, and is provided within a lower flange 109 connected to the valve body 101 so as to surround the outer periphery of the valve shaft 104.

[0005] In the lower flange 109, the bellows 108 is supported between a bellows ring 111 fitted onto the valve stem 104 and a bellows flange 112 sandwiched between the lower flange 109 and the upper flange 110. In order to further prevent external leakage of fluid, a gland packing 113 is provided in the upper flange 110 between the outer circumferential surface of the valve stem 104 and the inner circumferential surface of the upper flange 110. The lower part of the upper flange 110 serves as an upper cover for the lower flange 109.

[0006] A valve 100 equipped with such a bellows-like bellows 108 is called a bellows valve. In plants and the like where these valves are installed, efficient maintenance of a large number of valves is required, and a method for detecting damage to bellows valves has been proposed to improve the efficiency of the maintenance work (see Patent Document 1).

[0007] The valve maintenance support device disclosed in Patent Document 1 is capable of estimating whether or not the bellows valve is suspected to be damaged by presenting information about the maximum friction force of the bellows valve to an operator as a diagnostic index.

[0008] However, there are cases where even if the bellows 108 is damaged, the effect of the damage does not appear in the detection result of the friction force. Although leakage of fluid from the bellows 108 is a serious event, the technology disclosed in Patent Document 1 may not be able to detect damage to the bellows 108.

[0009] In petrochemical plants and the like, many valves are used. For example, in the example of Fig. 11, valves 100-A and 100-M are disposed in flow path 114-1, and valve 100-C is disposed in flow path 114-3. 115-A, 115-C, and 115-M are flow rate measuring instruments, 116 is a tank, and 117 is a pressure transmitter. In plants and the like in which many valves are used, further improvements in the efficiency of maintenance work are required. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2019-087003 A Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made to solve the above-mentioned problems, and has an object to provide a valve maintenance support device and method that can improve the work efficiency of bellows valve maintenance. [Means for solving the problem]

[0012] The valve maintenance support device of the present invention comprises: an opening command value storage unit configured to store data of an opening command value given to a bellows valve in association with an ID of the bellows valve that transmitted the data; an opening measurement value storage unit configured to store data of an actual opening value of the bellows valve in association with the ID of the bellows valve that transmitted the data; a full-opening data extraction unit configured to search for data of an opening command value instructing full opening among the opening command values ​​stored in the opening command value storage unit, and to extract, as diagnostic data, an actual opening value of the bellows valve to which this opening command value was given and an actual opening value for a time period corresponding to the opening command value instructing full opening; and a full-opening failure determination unit configured to determine, based on the diagnostic data, whether or not a full-opening failure state has occurred in which the bellows valve to which an opening command value instructing full opening was given does not fully open. a bellows damage determination unit configured to determine that a bellows valve has bellows damage when the full-open failure state occurs multiple times in the same bellows valve and the degree of insufficient opening in each of the multiple full-open failure states increases monotonically; and an ID of the bellows valve determined to have bellows damage by the bellows damage determination unit, and a determination result presenting unit configured to present the ID of the valve in which bellows damage has occurred.

[0013] Also In one configuration example of the valve maintenance support device of the present invention, the bellows damage determination unit is In the graph of the degree of insufficient opening relative to the number of times of the full opening failure state, When the degree of insufficient opening increases monotonically at a substantially constant rate, it is determined that the bellows valve is damaged.

[0014] A valve maintenance support method of the present invention includes a first step of storing data on an opening command value given to a bellows valve in association with an ID of the bellows valve that transmitted the data; a second step of storing data on an actual opening value of the bellows valve in association with the ID of the bellows valve that transmitted the data; a third step of searching for data on an opening command value instructing full opening from among the opening command values ​​stored in the first step and extracting, as diagnostic data, the actual opening value of the bellows valve to which this opening command value was given and the actual opening value for a time period corresponding to the opening command value instructing full opening; and a fourth step of determining, based on the diagnostic data, whether or not a full opening failure state has occurred in which the bellows valve to which an opening command value instructing full opening was given does not fully open. a fifth step of determining that a bellows valve has bellows damage when the full-open failure state occurs multiple times in the same bellows valve and the degree of insufficient opening in each of the multiple full-open failure states increases monotonically; and an ID of the bellows valve determined to have bellows damage in the fifth step is The ID of the valve with damaged bellows is presented. 6 The present invention is characterized by including the steps of:

[0015] Also In one embodiment of the valve maintenance support method of the present invention, 5 The steps are the same for the bellows valve. In the graph of the degree of insufficient opening relative to the number of times of the full opening failure state, The method is characterized by including a step of determining that bellows damage has occurred in the bellows valve when the degree of insufficient opening increases monotonically at a substantially constant rate. Effect of the Invention

[0016] According to the present invention, by monitoring the bellows valve for a full-open abnormality, it is possible to detect fluid leakage from the bellows and to assist the worker in selecting a bellows valve as a candidate for maintenance. As a result, the present invention can improve the efficiency of bellows valve maintenance work. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a block diagram showing the configuration of a valve maintenance support device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a flowchart illustrating the operation of the valve maintenance support device according to the first embodiment of the present invention. [Diagram 3] FIG. 3 is a flowchart illustrating the operation of the valve maintenance support device according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing an example of the opening operation of a bellows valve. [Diagram 5] FIG. 5 is a diagram showing an example in which the degree of insufficient opening increases monotonically at a substantially constant gradient. [Figure 6] FIG. 6 is a diagram showing an example in which the degree of insufficient opening does not increase monotonically. [Figure 7] FIG. 7 is a diagram showing an example in which the degree of insufficient opening increases, but the slope is not substantially constant. [Figure 8] FIG. 8 is a diagram showing the configuration of a plant and its device management system according to the second embodiment of the present invention. [Figure 9] FIG. 9 is a block diagram showing an example of the configuration of a computer that realizes the valve maintenance support device according to the first and second embodiments of the present invention. [Figure 10] FIG. 10 is a diagram showing an example of a control valve. [Figure 11] FIG. 11 is a diagram showing an example of a number of valves used in a tank of a plant. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] [Principle of the invention] The inventors have found that even when the damage to the bellows valve is so minor that it is difficult to detect the effect of the damage in frictional force detection, damage accompanied by leakage of fluid from the bellows (108 in FIG. 10) can become a serious event of fluid leakage. When the bellows is damaged, the fluid flowing through the valve penetrates from the outside of the bellows to the inside of the bellows. Furthermore, inside the bellows, the expansion and contraction of the bellows' bellows shape caused by the up and down movement of the valve stem (104 in FIG. 10) can act as a driving force for the fluid, causing the fluid to penetrate into the top cover (the lower part of the top flange 110 in FIG. 10) near the bellows joint. Since it is not originally expected that the top cover will come into contact with the fluid, leakage of the fluid from the bellows can be detected by monitoring the abnormality of the valve being fully open due to the intrusion of this fluid.

[0019] Furthermore, once fluid has entered the top cover, it will not disappear. Therefore, when the degree to which the valve does not fully open at a certain pace increases monotonically, there is a particular possibility of fluid leakage. In other words, if the valve becomes abnormally fully open and then suddenly resolves on its own, it is reasonable to assume that the cause is temporary adhesion of scale (such as carbon-based substances contained in the fluid flowing through the valve) in a location away from the bellows.

[0020] [First Example] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a block diagram showing the configuration of a valve maintenance support device according to a first embodiment of the present invention. In the following embodiments, in order to simplify the explanation, examples of IDs (identification information) of valves and the like are simpler than those used in an actual plant.

[0021] The valve maintenance support device includes a valve ID storage unit 1 that stores in advance the IDs of multiple bellows valves that can be candidates for maintenance, an opening acquisition unit 2 that acquires an opening command value given to a bellows valve and an actual opening value of the bellows valve, an opening command value storage unit 3 that stores data on the opening command value in association with the ID of the bellows valve that transmitted the data, and an opening measurement value storage unit 4 that stores data on the actual opening value in association with the ID of the bellows valve that transmitted the data, and a search is made for data on an opening command value that indicates full opening among the opening command values ​​stored in the opening command value storage unit 3, and a search is made for data on the actual opening value of the bellows valve to which this opening command value was given, the full-open data extraction unit 5 extracts as diagnostic data the actual opening value for the time period corresponding to the opening command value instructing full opening; a full-open failure determination unit 6 determines whether or not a full-open failure state has occurred in which the bellows valve, given an opening command value instructing full opening, does not fully open based on the diagnostic data; a bellows damage determination unit 7 determines that bellows damage has occurred in the bellows valve when a full-open failure state has occurred multiple times in the same bellows valve and the degree of insufficient opening in each of these multiple full-open failure states monotonically increases; and a determination result presentation unit 8 presents (displays) the ID of the bellows valve determined to have bellows damage.

[0022] 2 and 3 are flow charts for explaining the operation of the valve maintenance support device of this embodiment. In this embodiment, for example, let us say that there are 26 valves in a plant, and each of these 26 valves is assigned a unique ID, "A", "B", "C", . . ., "M", . . ., "X", "Y", and "Z", respectively. In particular, let us assume that the valves with valve IDs "A", "C", and "M" are bellows valves equipped with bellows, and that these IDs "A", "C", and "M" are stored in advance in the valve ID storage unit 1.

[0023] The positioner (102 in FIG. 10) used in each bellows valve supplies air pressure to the actuator (103 in FIG. 10) according to the difference between the opening command value SP (stem position command value) given by the higher-level device and the actual opening value PV (stem position measurement value) of the bellows valve.

[0024] The opening acquisition unit 2 acquires data on the opening command value SP and the actual opening value PV from the positioner of each bellows valve for which a valve ID is registered in the valve ID storage unit 1 (Step S100 in FIG. 2).

[0025] The opening acquisition unit 2 associates the data of the opening command value SP with the ID of the bellows valve that transmitted the data and information on the time the data was received, and stores them in the opening command value storage unit 3 (Step S101 in FIG. 2). The opening acquisition unit 2 also associates the data of the actual opening value PV with the ID of the bellows valve that transmitted the data and information on the time the data was received, and stores them in the opening measurement value storage unit 4 (Step S102 in FIG. 2).

[0026] The ID of the bellows valve may be obtained by the opening acquisition unit 2 from the valve ID that is added to the data of the opening command value SP and the actual opening value PV by the bellows valve positioner and transmitted. The time information may be added by the bellows valve positioner or by the opening acquisition unit 2.

[0027] In this manner, by repeating the processes of steps S100 to S102, time-series data of the opening command value SP and the actual opening value PV are accumulated in the opening command value storage unit 3 and the opening measurement value storage unit 4.

[0028] Next, the full-open data extraction unit 5 searches for data of the opening command value SP instructing full opening among the opening command values ​​SP stored in the opening command value storage unit 3 (step S103 in FIG. 3).Then, the full-open data extraction unit 5 extracts, as diagnostic data, the actual opening values ​​PV of the bellows valves (bellows valves with the same ID) to which the opening command value SP instructing full opening was given among the actual opening values ​​PV stored in the opening measurement value storage unit 4, and the actual opening values ​​PV in the time period corresponding to the opening command value SP instructing full opening (step S104 in FIG. 3).

[0029] The actual opening value PV in the time period corresponding to the opening command value SP commanding full open refers to the actual opening value PV from the same time as the opening command value SP commanding full open to the time after the predetermined time Top has elapsed. There is a delay in the response of the bellows valve to the opening command value SP. Therefore, for example, the above-mentioned predetermined time Top may be set to a time longer than the time required for a normal bellows valve to change from 0% to 100% opening. A normal bellows valve will be fully open within the predetermined time Top from the time when the opening command value SP commanding full open is given.

[0030] The full-open failure determination unit 6 determines, based on the diagnostic data extracted for the opening command value SP instructing full opening, whether or not a full-open failure state has occurred in which the bellows valve to which the opening command value SP instructing full opening has been given does not fully open (FIG. 3, step S105).

[0031] An example of the opening operation of a bellows valve is shown in Figures 4(A) and 4(B). In the example of Figure 4(A), the actual opening value PV of the bellows valve to which the opening command value SP instructing full opening is given becomes 100% within the predetermined time Top. In this case, the full-open failure determination unit 6 determines that the bellows valve is not in a full-open failure state.

[0032] On the other hand, in the example of Fig. 4(B), the actual opening value PV of the bellows valve does not reach 100% within the predetermined time Top. In this case, the full-open failure determination unit 6 determines that a full-open failure state has occurred in the bellows valve.

[0033] When it is determined that a fully open failure state has occurred in the bellows valve, and further when the same bellows valve has experienced a fully open failure state multiple times (YES in step S106 in FIG. 3), the bellows damage determination unit 7 determines whether the degree of insufficient opening Dif for each of the multiple fully open failure states is monotonically increasing (step S107 in FIG. 3).

[0034] The degree of opening deficiency Dif is the difference between the opening command value SP indicating full opening (100%) as shown in FIG. 4(B) and the maximum value of the actual opening value PV corresponding thereto. The period from when the opening command value SP indicates full opening until it becomes a value other than full opening is counted as one opening operation, and the state in which the bellows valve does not fully open during this one opening operation is counted as one state of incomplete full opening. The degree of opening deficiency Dif can be obtained during each determination process by the full opening deficiency determination unit 6.

[0035] When the degree of opening deficiency Dif of a plurality of states of incomplete full opening of the same bellows valve increases monotonically (YES in step S107), the bellows breakage determination unit 7 determines that bellows breakage has occurred in this bellows valve (step S108 in FIG. 3). At this time, when the degree of opening deficiency Dif of the same bellows valve increases monotonically with a substantially constant slope, the bellows breakage determination unit 7 determines that it is bellows breakage, and excludes cases where the slope is not substantially constant.

[0036] For example, FIG. 5 shows a case where the degree of opening deficiency Dif increases monotonically with a substantially constant slope. On the other hand, FIG. 6 shows a case that does not correspond to monotonic increase, and FIG. 7 shows a case where the degree of opening deficiency Dif increases but the slope is not substantially constant.

[0037] The method for determining whether or not the degree of opening deficiency Dif increases monotonically with a substantially constant slope may be determined as appropriate. For example, when the bellows breakage determination unit 7 linearly approximates the change in the degree of opening deficiency Dif by the least squares method, the coefficient of determination R 2 (0 ≦ R 2 ≦ 1) is a real number greater than or equal to a predetermined value TH (TH is a real number where 0 < TH ≦ 1) and less than or equal to 1, it may be determined that the degree of opening deficiency Dif increases monotonically with a substantially constant slope. This method is an example, and it goes without saying that other determination methods may be used. The reason why the degree of opening deficiency Dif increases monotonically with a substantially constant slope is that the fluid gradually penetrates into the upper lid while accompanied by the viscous resistance of the fluid. However, in the case of FIG. 7, it is preferable to regard it as an abnormality different from bellows breakage (such as adhesion of a scale that does not peel off).

[0038] In addition, in this embodiment, if a full-open failure state occurs multiple times in the same bellows valve, it is determined whether the degree of insufficient opening Dif is monotonically increasing. The above-mentioned multiple times may be, for example, N times or more (N is an integer of 3 or more).

[0039] The determination result presenting unit 8 presents to the worker the valve IDs of the bellows valves determined to have bellows damage, among the bellows valves whose valve IDs are registered in the valve ID storage unit 1 (Step S109 in FIG. 3).

[0040] However, the determination result presenting unit 8 may present (display) information on either "damaged" or "not damaged" for all bellows valves whose valve IDs are registered in the valve ID storage unit 1. In this case, the worker (operator) can also check the valve IDs of bellows valves that were found not to be damaged as a result of the bellows damage determination.

[0041] In this manner, the processing of steps S100 to S109 in Fig. 3 is periodically performed. Note that, in the flowchart of Fig. 3, it is determined that bellows damage has occurred in a bellows valve in which the degree of insufficient opening Dif increases monotonically at a substantially constant rate, but the processing by bellows damage determination unit 7 (steps S106 to S108) may be omitted. In this case, the determination result presentation unit 8 may present (display) the valve ID of the bellows valve that full-open failure determination unit 6 has determined to be in a full-open failure state as the ID of a valve with bellows damage.

[0042] In this embodiment, by monitoring the bellows valve for abnormalities when fully open, it is possible to detect fluid leakage from the bellows, and to assist the worker in selecting a bellows valve as a candidate for maintenance.

[0043] [Second Example] Next, a second embodiment of the present invention will be described. This embodiment describes an implementation example of the first embodiment. Figure 8 is a diagram showing the configuration of a plant and its equipment management system, and the same components as those in Figure 11 are given the same reference numerals.

[0044] An equipment management system for a petroleum or chemical plant is provided with a management device 10 that controls and manages each piece of equipment in the plant. The valve ID storage unit 1, the opening acquisition unit 2, the opening command value storage unit 3, and the opening measurement value storage unit 4 described in the first embodiment handle a huge amount of information specific to the plant, so they are preferably implemented in the management device 10.

[0045] On the other hand, the full-open data extraction unit 5, the full-open failure determination unit 6, the bellows damage determination unit 7, and the determination result presentation unit 8 provide processing that is required in principle only when determining whether valve maintenance is required. Also, a maintenance implementer (a worker at a maintenance contracted company) generally performs plant maintenance on behalf of a plant owner company. Therefore, assuming that an unspecified number of plants will be the target, it is preferable to implement the full-open data extraction unit 5, the full-open failure determination unit 6, the bellows damage determination unit 7, and the determination result presentation unit 8 in a portable computer 11 carried around by a worker (operator) at the maintenance contracted company.

[0046] The plant management device 10 and the computer 11 are temporarily connected to each other using a communication function such as Ethernet (registered trademark) when maintenance work is performed. When an operator starts the application software on the computer 11, the CPU (Central Processing Unit) of the computer 11 executes processing according to the program stored in the memory, and realizes the functions of a full-open data extraction unit 5, a full-open failure judgment unit 6, a bellows damage judgment unit 7, and a judgment result presentation unit 8.

[0047] The judgment result presentation unit 8 reads the valve ID from the valve ID memory unit 1 on the management device 10 and also reads the judgment result of the bellows damage judgment unit 7 (or the full-open failure judgment unit 6), and displays the ID of the bellows valve that has been judged to have bellows damage on the display of the computer 11 (Figure 3, step S109).

[0048] The operator checks the bellows valves that require particular attention for bellows inspection based on the displayed valve ID. After checking the displayed items, the operator disconnects the computer 11 from the management device 10. In this manner, the valve maintenance support device described in the first embodiment can be applied to an actual plant.

[0049] The valve maintenance support device described in the first and second embodiments can be realized by a computer equipped with a CPU, a storage device, and an interface, and a program that controls these hardware resources. An example of the configuration of this computer is shown in Fig. 9. The computer is equipped with a CPU 300, a storage device 301, and an interface device (I / F) 302. For example, a valve, a management device, a display, etc. are connected to the I / F 302. In such a computer, a program for realizing the valve maintenance support method of the present invention is stored in the storage device 301. The CPU 300 executes the processing described in the first and second embodiments in accordance with the program stored in the storage device 301. When the valve maintenance support device is implemented separately in the management device 10 and the computer 11 as in the second embodiment, each of them may be realized with a configuration as shown in FIG. [Industrial Applicability]

[0050] The present invention can be applied to a technique for supporting valve maintenance work. [Explanation of symbols]

[0051] 1...valve ID memory unit, 2...opening degree acquisition unit, 3...opening degree command value memory unit, 4...opening degree measurement value memory unit, 5...full opening data extraction unit, 6...full opening failure determination unit, 7...bellows damage determination unit, 8...determination result presentation unit, 10...management device, 11...computer.

Claims

1. an opening command value storage unit configured to store data of an opening command value given to the bellows valve in association with an ID of the bellows valve that is a source of the data; an opening measurement value storage unit configured to store data of an actual opening value of the bellows valve in association with an ID of the bellows valve that is a sender of the data; a full-open data extraction unit configured to search for data of an opening command value instructing full opening among the opening command values ​​stored in the opening command value storage unit, and to extract, as diagnostic data, an actual opening value of the bellows valve to which the opening command value was given, and an actual opening value of a time period corresponding to the opening command value instructing full opening; a full-open failure determination unit configured to determine whether or not a full-open failure state occurs in which the bellows valve is not fully opened when an opening command value instructing full opening is given based on the diagnostic data; and a bellows damage determination unit configured to determine that a bellows valve has been damaged when the full-open failure state occurs multiple times in the same bellows valve and the degree of insufficient opening in each of the multiple full-open failure states increases monotonically; and a judgment result presentation unit configured to present the ID of a bellows valve for which the bellows damage determination unit has determined that bellows damage has occurred as the ID of a valve in which bellows damage has occurred.

2. 2. The valve maintenance support device according to claim 1, The valve maintenance support device is characterized in that the bellows damage determination unit determines that bellows damage has occurred in the bellows valve when the degree of insufficient opening increases monotonically with a substantially constant slope in a graph of the degree of insufficient opening against the number of times the same bellows valve has been in the fully open failure state.

3. A first step of storing data of an opening command value given to a bellows valve in association with an ID of the bellows valve that is a source of the data; a second step of storing the data of the actual opening value of the bellows valve in association with the ID of the bellows valve that is the sender of the data; a third step of searching for data of an opening command value instructing full opening from among the opening command values ​​stored in the first step, and extracting, as diagnostic data, an actual opening value of the bellows valve to which this opening command value was given and an actual opening value in a time period corresponding to the opening command value instructing full opening; a fourth step of determining whether or not a full-open insufficient state occurs in the bellows valve to which an opening command value instructing full opening is given based on the diagnostic data; and a fifth step of determining that a bellows valve is damaged when the full-open failure state occurs multiple times in the same bellows valve and the degree of insufficient opening in each of the multiple full-open failure states increases monotonically; and a sixth step of presenting the ID of the bellows valve determined to have bellows damage in the fifth step as the ID of the valve in which bellows damage has occurred.

4. The valve maintenance support method according to claim 3, the fifth step including a step of determining that bellows damage has occurred in the bellows valve when the degree of insufficient opening increases monotonically with a substantially constant slope in a graph of the degree of insufficient opening against the number of times the same bellows valve has been in the fully open failure state.

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