JP2020106064A - Diagnosis method for gate valve and gate valve diagnosis system - Google Patents

Abstract

To provide a diagnosis method for a gate valve capable of diagnosing a failure of the gate valve without stopping operation of the gate valve, and a gate valve diagnosis system.SOLUTION: The present invention relates to a diagnosis method for a gate valve 1 for diagnosing a failure of the gate valve 1 in which a guide rail 20 for guiding a valve body 4 which opens/closes a flow channel 3 in an opening/closing direction is provided within a valve box 2. The valve box 2 comprises a valve box main body part 7 including a flow channel 3, and a bonnet part 8. The valve body 4 is moved in the opening/closing direction in slide contact with the guide rail 20 by a fluid pressure type actuation device 6, rushes into the valve box main body part 7 at a closing position to shut down the flow channel 3 and leaves the inside of the valve box main body part 7 to the inside of the bonnet part 8 at an opening position. The present invention also relates to the method and a gate valve diagnosis system in which an actuation pressure of the actuation device 6 for moving the valve body 4 in the opening/closing direction is detected and the failure of the gate valve 1 is diagnosed on the basis of a change in the detected actuation pressure.SELECTED DRAWING: Figure 5

Description

The present invention relates to, for example, a diagnosing method for a sluice valve having a disc-shaped valve body and a sluice valve diagnosing system.

Conventionally, as a sluice valve of this type, for example, there is a sluice valve as shown in Patent Document 1. The gate valve disclosed in Patent Document 1 is provided with a valve body (gate) that opens and closes a flow path and a guide device that guides the valve body in an opening and closing direction in a valve box. The valve box has a valve box main body having a flow path, and a bonnet portion formed on an outer peripheral portion of the valve box main body. The guide device includes guide members installed at four locations. Each of the guide members is installed in a guide sliding section in the opening/closing direction, and is fixed to the inner surface of the valve box by welding.

In the conventional sluice valve as disclosed in Patent Document 1, opening and closing of the valve element is repeated every predetermined time. Therefore, the movement of the valve element may cause the seat portion to be worn or damaged. Further, in the conventional sluice valve, when the valve body is opened, high-temperature fluid flows into the valve body and the bonnet portion, and when the valve body is closed, nitrogen gas lower than the fluid temperature is generated. Filled inside the bonnet. Therefore, opening and closing the valve element causes a temperature difference between the guide member and the valve box, and this temperature difference may damage the welded portion that fixes the guide member to the valve box. For this reason, in the conventional sluice valve, it is necessary to regularly inspect or replace the seat portion and the guide member.

JP, 2014-080996, A

However, in the conventional gate valve, in order to inspect or replace the seat portion and the guide member, it is necessary to confirm the internal states of the valve box body and the bonnet portion. Therefore, there is a problem that the operation of the sluice valve must be stopped only to check the internal states of the valve box body and the bonnet portion. In particular, when inspecting or replacing the seat part and the guide member in equipment that operates multiple sluice valves at the same time, the operation must be stopped regardless of the state of each sluice valve. There was a problem that the operating efficiency of the gate valve deteriorates.

An object of the present invention is to provide a diagnosing method of a sluice valve capable of diagnosing a malfunction of the sluice valve without stopping operation of the sluice valve.

In order to achieve the above object, in the method for diagnosing a sluice valve of the present invention, a guide member that guides a valve body that opens and closes a flow path in an opening and closing direction is provided in the valve box, and the valve box has a flow path. The valve body has a valve body and a bonnet, and the valve body moves in the opening/closing direction while slidingly contacting the guide member by a fluid pressure type actuating device, and at the closed position, the valve body projects into the valve body to form a flow path. A method for diagnosing a sluice valve that shuts off and retreats from the inside of the valve box body into the hood at the open position, the operating pressure of the actuating device for moving the valve body in the opening/closing direction. Is detected and the malfunction of the sluice valve is diagnosed based on the detected change in the operating pressure.

According to this, since the malfunction of the sluice valve is diagnosed based on the change of the working pressure in the actuating device for moving the valve body in the opening/closing direction, the state of the sluice valve can be estimated without stopping the operation of the sluice valve.

The method for diagnosing a sluice valve of the present invention is the method for diagnosing a sluice valve according to the method for diagnosing the surface pressure of the guide member based on a change in the operating pressure detected by detecting the operating pressure of the operating device. is there.

According to this, since the surface condition of the guide member is diagnosed based on the change in the operating pressure of the actuator, the surface condition of the guide member can be estimated without stopping the operation of the sluice valve.

The method for diagnosing a sluice valve according to the present invention is the method for diagnosing a sluice valve, wherein the operating pressure of the operating device is detected, and the guide attached to the valve box is based on a change in the detected operating pressure. This is a method of diagnosing the attachment state of the member.

According to this, the attachment state of the guide member attached to the valve box is diagnosed based on the change in the operating pressure of the actuator, so that the attachment state of the guide member can be estimated without stopping the operation of the sluice valve.

The method for diagnosing a sluice valve of the present invention is the method for diagnosing a sluice valve, wherein the operating pressure of the actuating device when moving the valve body from a closed position to an open position is detected, and a change in the detected operating pressure is detected. Is a method of diagnosing a defect in the seat portion of the sluice valve.

According to this, since the malfunction of the seat part of the sluice valve is diagnosed based on the change in the operating pressure of the actuating device when the valve body is moved from the closed position to the open position, the sluice valve can be operated without stopping the sluice valve. The state of the seat part of can be estimated.

The method for diagnosing a sluice valve according to the present invention is the method for diagnosing a sluice valve, wherein, when the valve body is in the closed position, the supply pressure of the purge gas supplied to the bonnet portion and the purge gas inside the bonnet portion. The pressure difference between the pressure and the pressure difference is detected, and based on the change in the detected pressure difference, the leak amount of the purge gas leaked from the bonnet portion to the flow path through the gap between the seat portion and the valve body is determined. It is a method of estimating and diagnosing a defect in the seat portion based on the estimated leak amount of the purge gas.

According to this, since the defect of the seat part is diagnosed based on the leakage amount of the purge gas estimated from the change in the pressure difference between the supply pressure of the purge gas supplied to the bonnet part and the pressure of the purge gas inside the bonnet part, The state of the seat can be estimated without stopping the operation of the valve.

The method for diagnosing a sluice valve of the present invention is the method for diagnosing a sluice valve, wherein the operating pressure of the actuating device in a section in which the valve body moves in the opening/closing direction while slidingly contacting the guide member is detected and detected. A method of diagnosing a surface state of the guide member and an attached state of the guide member attached to the valve box based on a change in operating pressure.

According to this, by extracting the data in the above section from the detected operating pressure data of the operating device, the surface state of the guide member and the mounting state of the guide member attached to the valve box can be determined. Can be estimated.

The method for diagnosing a sluice valve of the present invention is the method for diagnosing a sluice valve, wherein the actuation pressure of the actuating device is detected in a section in which the valve body moves in the opening/closing direction while slidingly contacting the seat portion, and is detected. A method of diagnosing the surface condition of the seat portion based on a change in operating pressure.

According to this, the surface state of the seat portion can be estimated by extracting the data in the section from the detected data of the operating pressure of the operating device.

In the sluice valve diagnostic system of the present invention, a guide member that guides a valve body that opens and closes a flow path in an opening and closing direction is provided in the valve box, and the valve box includes a valve box main body section having a flow path and a bonnet section. The valve body moves in the opening/closing direction while slidingly contacting the guide member by a fluid pressure type actuating device, penetrates into the valve box main body at the closed position to block the flow path, and opens in the valve box main body. A sluice valve diagnostic system for diagnosing a malfunction of a sluice valve that retreats from the inside of the hood into the bonnet portion, wherein an actuation pressure detection device detects an actuation pressure of the actuation device for moving the valve element in the opening/closing direction, and A sluice valve diagnostic device for diagnosing a malfunction of the sluice valve based on a change in the actuation pressure detected by the actuation pressure detection device.

The sluice valve diagnosis device diagnoses malfunctions of the sluice valve based on changes in the working pressure of the valve disc actuation device detected by the actuation pressure detection device, so the sluice valve status is estimated without stopping the sluice valve operation. it can.

As described above, according to the present invention, the partitioning is performed based on the change in the operating pressure of the operating device for moving the valve element in the opening/closing direction and the change in the pressure difference between the supply pressure of the purge gas and the pressure of the purge gas inside the bonnet portion. Since the valve malfunction is diagnosed, the state of the sluice valve can be estimated without stopping the operation of the sluice valve. Further, since the state of the sluice valve can be estimated without stopping the operation of the sluice valve, the state of each sluice valve can be checked when the seat part and the guide member are inspected or replaced in the equipment that operates a plurality of sluice valves at the same time. It is possible to estimate an appropriate treatment time according to the above, and it is possible to improve the operation efficiency of the gate valve in the entire equipment.

It is a perspective view of the gate valve in an embodiment of the invention. It is the figure which looked at the same sluice valve from the inflow port side, and half shows an outer surface and the other half shows a horizontal section. It is a XX arrow line view in FIG. It is a longitudinal cross-sectional view of the same gate valve, showing a fully closed state. It is a block diagram which shows the structure of the diagnostic device which diagnoses the same sluice valve. It is a flowchart which shows the diagnostic method which uses the "surface state of a guide rail" and the "attachment state of a guide rail" in the diagnosis of the same gate valve. 6 is a graph showing changes over time in the operating pressures on the rod side and head side of the hydraulic cylinder and the differential pressures thereof in a diagnostic method using the “surface condition of the guide rail” and the “mounting condition of the guide rail” in the diagnosis of the gate valve. .. The graph which shows the time-dependent change of the moving average with respect to the differential pressure of the operating pressure of the rod side and the head side of the hydraulic cylinder in the diagnostic method using the "surface condition of the guide rail" and the "mounting condition of the guide rail" in the diagnosis of the same gate valve. Is. Time-dependent change of the moving average with respect to the differential pressure of the operating pressure on the rod side and the head side of the hydraulic cylinder in the diagnostic method using the "surface condition of the guide rail" and the "mounting condition of the guide rail" in the diagnosis of the sluice valve, and Hotelling statistics It is a graph which shows the abnormal value calculated from the quantity, when the number of abnormal values exceeds a predetermined value. Time-dependent change of the moving average with respect to the differential pressure of the operating pressure on the rod side and the head side of the hydraulic cylinder in the diagnostic method using the "surface condition of the guide rail" and the "mounting condition of the guide rail" in the diagnosis of the sluice valve, and Hotelling statistics It is a graph which shows the abnormal value calculated from quantity, when the number of abnormal values is below a predetermined value. It is a flowchart which shows the diagnostic method which uses the "surface state of a seat part" in the diagnosis of the same sluice valve.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, the sluice valve 1 diagnosed by the method of the present invention will be described. As shown in FIGS. 1 to 4, the sluice valve 1 moves a valve body 4 (gate) that opens and closes a vertical passage 3 in a valve box 2 and a valve body 4 in opening and closing directions A and B. And an guiding device 5 for guiding the valve element 4 in the opening/closing directions A and B. The opening/closing directions A and B are set in the horizontal direction orthogonal to the flow path 3.

The valve box 2 has a valve box body portion 7 having a flow passage 3 inside, and a bonnet portion 8 (valve body storage portion) formed on an outer peripheral portion of the valve box body portion 7. The valve box main body 7 has an inflow port 9 in the upper part and an outflow port 10 in the lower part.

A seat portion 11 is provided in the valve box body portion 7. As shown in FIG. 2, at the fully closed position S, the valve body 4 rushes into the valve body 7 to shut off the flow path 3. The inside of the valve body 7 and the inside of the hood 8 communicate with each other. At the fully open position O, the valve body 4 retracts into the bonnet portion 8 from within the valve box body portion 7. A purge pipe 12 for injecting a nitrogen gas 19, which is an example of a purge gas, into the bonnet portion 8 is connected to the valve box 2. The nitrogen gas 19 is supplied from the nitrogen gas supply equipment 90 (FIG. 5), and the supply pressure is detected by the supply pressure sensor 91 (FIG. 5). As shown in FIG. 1, a bonnet pressure sensor 28 that detects the pressure of the nitrogen gas 19 inside the bonnet portion 8 is provided above the bonnet portion 8.

The valve body 4 is composed of a pair of upper and lower double discs 13, and is connected to an end portion of a valve rod 14. The valve stem 14 has a wedge 15 at its end. The wedge 15 is a wedge-shaped member that contracts toward the end of the valve body 4 in the closing direction B, and has a pair of inclined surfaces 16. These inclined surfaces 16 contact a pressure receiving surface 17 formed on the double disk 13. In addition, as shown in FIG. 2, the double disc 13 has guide protrusions 18 that project outward in the radial direction on both sides in the width direction. The width direction of the double disk 13 of the valve body 4, the opening/closing directions A and B, and the flow path axial direction of the flow path 3 are orthogonal to each other.

The actuating device 6 is a fluid pressure type driving device, and moves the valve body 4 in the opening/closing directions A and B by the action of a predetermined fluid pressure (hydraulic pressure). The operating device 6 has a hydraulic cylinder 25, and the reciprocating motion of the hydraulic cylinder 25 moves the valve rod 14 in the horizontal direction to move the valve body 4 in the horizontal direction. The operating device 6 includes a rod-side pressure sensor 26 that detects a rod-side operating pressure (hydraulic pressure) of the hydraulic cylinder 25, and a head-side pressure sensor 27 that detects a head-side operating pressure (hydraulic pressure) of the hydraulic cylinder 25. Have.

The guide device 5 includes four long guide rails 20 (an example of a “guide member”) that are long in the opening/closing directions A and B. Each of the guide rails 20 is welded to the inner surface of the valve box 2 in the opening/closing directions A and B (longitudinal direction).

Next, the operation of the above configuration will be described.
As shown in the phantom line in FIG. 2 and in FIG. 3, when the valve body 4 is moved to the fully open position O by operating the operating device 6, the valve body 4 retreats into the bonnet portion 8 and, for example, high temperature air or A high-temperature fluid 31 such as light hydrocarbon flows through the flow path 3 from the upstream side to the downstream side. At this time, a part of the fluid 31 flows into the bonnet portion 8 from the inside of the valve box body portion 7.

Further, as shown by the solid line in FIG. 2 and FIG. 4, when the valve body 4 is moved to the fully closed position S by operating the actuating device 6, the valve body 4 plunges into the valve body 7 and the wedge The inclined surface 16 of 15 is pressed against the pressure receiving surface 17 of the double disk 13, and the double disk 13 is pressed against the seat portion 11 to block the flow path 3.

When the valve body 4 moves from the fully open position O to the fully closed position S, nitrogen gas 19 is injected into the bonnet portion 8 from the purging pipe 12, and the fluid 31 in the bonnet portion 8 is caused by the nitrogen gas 19 into the valve box. It is expelled into the main body portion 7 and the inside of the bonnet portion 8 is filled with the nitrogen gas 19. Since the pressure of the nitrogen gas 19 is higher than the pressure of the fluid 31, the fluid 31 can be prevented from entering the bonnet portion 8 from the upstream side of the valve body 4 at the fully closed position S. Therefore, the fluid 31 does not leak from the upstream side of the valve body 4 at the fully closed position S to the downstream side of the valve body 4 by bypassing the inside of the bonnet portion 8. When the valve body 4 is in the fully closed state, the nitrogen gas 19 is filled in the gap formed between both double disks 13 of the valve body 4.

Next, a method of diagnosing the gate valve 1 will be described. As shown in FIG. 5, the gate valve 1 is diagnosed by the gate valve diagnosis system 40. The sluice valve diagnostic system 40 diagnoses a malfunction of the sluice valve 1, and particularly diagnoses a surface condition of the guide rail 20, a mounting condition of the guide rail 20, and a malfunction of the seat portion 11 of the sluice valve 1. The sluice valve diagnosis system 40 is connected to each of the plurality of sluice valves 1 provided in the facility, and individually diagnoses the plurality of sluice valves 1 connected. In addition, the sluice valve diagnosis system 40 may be connected to only the sluice valve 1 that performs diagnosis among the plurality of sluice valves 1 provided in the facility.

The sluice valve diagnosis system 40 includes a supply pressure of the nitrogen gas 19 supplied from the nitrogen gas supply facility 90 to the bonnet portion 8, a pressure of the nitrogen gas 19 inside the bonnet portion 8, and a rod side and a head side of the hydraulic cylinder 25. The detection device 41 detects an operating pressure (hydraulic pressure) (an example of an “operating pressure detection device”), and a sluice valve diagnostic device 44 that diagnoses a malfunction of the sluice valve 1 based on a detection result of the detection device 41. The detection device 41 and the sluice valve diagnosis device 44 have communication control units 43 and 45, respectively, and transmit and receive data to and from each other via these. Note that, as shown in FIG. 5, in the present embodiment, the detection device 41 and the sluice valve diagnosis device 44 are independent devices, and data is transmitted and received between the two devices, but the present invention is not limited to this. Instead of this, the detection device and the sluice valve diagnosis device may be configured as an integrated device. The configurations of the detection device 41 and the sluice valve diagnostic device 44 are not limited to the following configurations, and the sluice valve is based on the detected pressure of the nitrogen gas 19 and the operating pressure (hydraulic pressure) of the hydraulic cylinder 25. Any configuration may be used as long as it is possible to diagnose the defect of item 1.

The detection device 41 includes a rod-side pressure sensor 26 that detects a rod-side operating pressure (hydraulic pressure) of the hydraulic cylinder 25, a head-side pressure sensor 27 that detects a head-side operating pressure (hydraulic pressure) of the hydraulic cylinder 25, and a bonnet. A bonnet pressure sensor 28 that detects the pressure (bonnet pressure) of the nitrogen gas 19 inside the portion 8, and a supply pressure sensor 91 that detects the supply pressure of the nitrogen gas 19 supplied from the nitrogen gas supply equipment 90 to the bonnet portion 8. , A detection-side storage unit 42 that stores the pressure value detected by each of the pressure sensors 26, 27, 28, and 91, and a detection-side communication that transmits the pressure value stored in the detection-side storage unit 42 to the sluice valve diagnostic device 44. The controller 43 is mainly provided. The detection device 41 detects the pressure of the nitrogen gas 19 or the operating pressure (hydraulic pressure) of the hydraulic cylinder 25 by the pressure sensors 26, 27, 28, 91, and stores the detected value in the detection side storage unit 42 and stores it. The detected value is transmitted to the sluice valve diagnosis device 44 through the detection side communication control unit 43.

The sluice valve diagnostic device 44 includes a processing-side communication control unit 45 that receives the detection value transmitted from the detection device 41, a processing-side storage unit 46 that stores the detection value received by the processing-side communication control unit 45, and a processing. A determination unit 47 that determines a malfunction of the sluice valve 1 based on the detection value stored in the side storage unit 46, and a display unit 48 that displays the determination result determined by the determination unit 47 are mainly provided. In the sluice valve diagnostic device 44, the detection value transmitted from the detection device 41 is received by the processing-side communication control unit 45 and stored in the processing-side storage unit 46, and the determination unit 47 causes the sluice valve 1 to be stored based on the stored detection value. The failure is determined and the determination result is displayed on the display unit 48.

The detecting device 41 and the gate valve diagnosing device 44 are not limited to those configured by a computer or the like, and may be a server or a server group via a network. Further, the data of the detection values stored in the detection side storage unit 42 and the processing side storage unit 46 are not used only for diagnosing the malfunction of the sluice valve 1, but the specifics of the malfunction of the sluice valve 1 described below. In the conventional diagnostic method, it is also used when updating the thresholds (T1, T2, T3) used for abnormality determination as needed.

Next, a specific method of diagnosing the malfunction of the gate valve 1 will be described. Diagnosis of the malfunction of the sluice valve 1 is performed by using the feature amount for determining the malfunction of the sluice valve 1. Here, the characteristic amount for determining the malfunction of the sluice valve 1 includes “surface state of the guide rail 20”, “mounting state of the guide rail 20”, “surface state of the seat portion 11”, “from the bonnet portion 8”. , The amount of leakage of the nitrogen gas 19 that leaks into the flow path 3 through the gap between the seat portion 11 and the valve body 4”. Hereinafter, a method of diagnosing a malfunction of the sluice valve 1 using each feature will be described. The determination of the malfunction of the sluice valve 1 described below is performed by the determination unit 47 of the sluice valve diagnosis device 44 of the sluice valve diagnosis system 40.

[Surface condition of the guide rail 20 and mounting condition of the guide rail 20]
In the diagnosis using the "surface condition of the guide rail 20" and the "mounting condition of the guide rail 20" which are the characteristic quantities for judging the malfunction of the sluice valve 1, the surface condition of the guide rail 20 or the valve box 2 is detected. By determining the superiority or inferiority of the mounting state (welding state) of the guide rail, the malfunction of the guide rail 20 is diagnosed. The diagnosis using the "surface condition of the guide rail 20" and the "mounting condition of the guide rail 20" is performed by operating pressure (hydraulic pressure) on the rod side of the hydraulic cylinder 25 when the valve body 4 is opened and closed, and when the valve body 4 is opened and closed. And the operating pressure (hydraulic pressure) on the head side of the hydraulic cylinder 25 in the above. Specifically, as shown in FIGS. 6 and 7, first, the operating pressure on the rod side of the hydraulic cylinder 25 detected by the rod side pressure sensor 26 and the hydraulic cylinder 25 detected by the head side pressure sensor 27 are detected. The differential pressure between the two pressures is calculated from the operating pressure on the head side (S1). As shown in FIG. 8, a moving average for the calculated differential pressure between the two pressures is calculated (S2).

Further, with respect to the calculated moving average of the differential pressures of both pressures, the average and variance of the differential pressures of both pressures in the evaluation section are calculated (S3). That is, the data pattern at the calculated pressure difference between the two pressures is quantitatively evaluated. Here, the evaluation section is a section (guide operation section) in which the valve body 4 is in contact with the guide rail 20 and slides in a steady state when the "attachment state of the guide rail 20" is used.

A Hotelling statistic is calculated from the moving average of the pressure difference between the two pressures and the average and variance of the calculated pressure difference between the pressures (S4). That is, the degree of abnormality of the data of the differential pressure between the two pressures to be verified is calculated. Next, the probability of the chi-square distribution with one degree of freedom is calculated from the calculated Hotelling statistic, the probability values of normal X1 and abnormal X2 are determined from past defect data, and as a threshold value for determining the abnormal value E. Define (S5). Further, when the value is smaller than the threshold value, the abnormal value E is set, and the number of the abnormal value E in the evaluation section is counted (S6). Then, it is determined whether or not the number of abnormal values E in the evaluation section exceeds a predetermined value T1 (S7). Here, the predetermined value T1 is the number of the abnormal value E counted in the above (S1) to (S6) in the past, and is the "surface state of the guide rail 20" or "mounting state of the guide rail 20". A value calculated from the number of abnormal values E counted when a problem (abnormality) occurs in the above. As shown in FIG. 9, when the number of abnormal values E in the evaluation section (the number of black points in FIG. 9) exceeds the predetermined value T1 (S7-Yes), “the surface state of the guide rail 20 is indicated. Alternatively, it is determined that the "mounting state of the guide rail 20" is abnormal (S8). That is, it is diagnosed that the guide rail 20 is defective. On the other hand, as shown in FIG. 10, when the number of abnormal values E in the evaluation section (the number of black points in FIG. 10) is not more than the predetermined value T1 (S7-No), “the surface of the guide rail 20 is detected. It is determined that the "state" or the "attachment state of the guide rail 20" is normal (S9). That is, it is diagnosed that the guide rail 20 has no defect.

In this way, the diagnosis using the "surface condition of the guide rail 20" and the "mounting condition of the guide rail 20", which are the characteristic quantities for determining the malfunction of the sluice valve 1, is used for the operation pressure (hydraulic pressure) of the hydraulic cylinder 25. Anomaly detection (outlier detection) by Hotelling theory using the detection data of. In addition, the diagnosis is performed using detection data of the operating pressure (hydraulic pressure) of the hydraulic cylinder 25 in a specific evaluation section.

[Surface Condition of Seat Part 11]
In the diagnosis using the “surface condition of the seat portion 11 ”, which is a feature amount for determining the malfunction of the sluice valve 1, the malfunction of the seat portion 11 is diagnosed by determining the superiority or inferiority of the surface condition of the seat portion 11. Diagnosis using the "surface condition of the seat portion 11" is performed by operating pressure (hydraulic pressure) on the rod side of the hydraulic cylinder 25, operating pressure (hydraulic pressure) on the head side of the hydraulic cylinder 25, and nitrogen gas 19 inside the bonnet portion 8. Pressure (bonnet pressure) and the detection data of. In addition, as each detection data, only the data when the valve body 4 is opened (when the valve body 4 is moved from the fully closed position S to the fully open position O) is used.

Specifically, as shown in FIG. 11, the operating pressure on the rod side of the hydraulic cylinder 25 detected by the rod side pressure sensor 26 and the operating pressure on the head side of the hydraulic cylinder 25 detected by the head side pressure sensor 27. From the above, the pressure difference between the two pressures is calculated (S11). The average pressure P1 in the seat sliding section (the section in which the valve body 4 slides in contact with the seat portion 11) of the calculated differential pressure between the two pressures is calculated (S12). From the calculated average pressure P1 and the pressure receiving area S1 of the hydraulic cylinder 25, the pulling force F1 of the valve body 4 is calculated by the following formula (1) (S13).
F1=P1×S1 Formula (1)

Subsequently, the calculated pulling force F1 of the valve body 4, the pressure of the nitrogen gas 19 inside the bonnet portion 8 (bonnet pressure P2), the pressure P3 on the inlet 9 side of the upper portion of the valve body 7, and the valve From the pressure receiving area S2 of the double disk 13 of the body 4, the friction coefficient μ1 of the valve body 4 in the seat sliding section is calculated by the following equation (2) (S14).
μ1=F1/(2(P2-P3)×S2) Formula (2)

Then, it is determined whether the bonnet pressure P2 is less than or equal to the predetermined value T2 and the friction coefficient μ1 is less than or equal to the predetermined value T3 (S15). Here, the predetermined value T2 is a value calculated from the bonnet pressure P2 detected when a defect (abnormality) has occurred in the "surface state of the seat portion 11" in the past. Further, the predetermined value T3 is the maximum value of the values calculated from past measurement data and having no abnormality in the "surface condition of the sheet portion 11".

When the bonnet pressure P2 is less than or equal to the predetermined value T2 and the friction coefficient μ1 is less than or equal to the predetermined value T3 (S15-Yes), it is determined that the "surface state of the seat portion 11" is abnormal (S16). That is, it is diagnosed that the seat portion 11 is defective. On the other hand, when the bonnet pressure P2 is equal to or less than the predetermined value T2 and the friction coefficient μ1 is not equal to or less than the predetermined value T3 (S15-No), the bonnet pressure P2 is further equal to or less than the predetermined value T2 or the friction coefficient μ1 is equal to the predetermined value T3. It is determined whether one of the following is applicable (S17). When the bonnet pressure P2 is equal to or less than the predetermined value T2 or the friction coefficient μ1 is equal to or less than the predetermined value T3 (S17-Yes), the "surface state of the seat portion 11" is in an abnormally close state ( It is determined to be a warning state (S18). That is, it is diagnosed that the seat portion 11 is close to the defective state. When the bonnet pressure P2 does not correspond to the predetermined value T2 or less or the friction coefficient μ1 does not correspond to the predetermined value T3 or less (S17-No), it is determined that the "surface state of the seat portion 11" is normal. (S19). That is, it is diagnosed that the seat portion 11 has no defect.

As described above, the diagnosis using the "surface state of the seat portion 11" which is the characteristic amount for determining the malfunction of the sluice valve 1 is performed by operating pressure (hydraulic pressure) on the rod side of the hydraulic cylinder 25 and the head of the hydraulic cylinder 25. The friction coefficient μ1 of the valve element 4 in the seat sliding section is obtained based on the detection data of the side operating pressure (hydraulic pressure) and the pressure of the nitrogen gas 19 inside the bonnet portion 8 (bonnet pressure). .. In addition, the diagnosis is performed using detection data of the operating pressure (hydraulic pressure) of the hydraulic cylinder 25 in a specific evaluation section.

[Amount of Leakage of Nitrogen Gas 19 Leaking to the Flow Path 3 from the Bonnet Section 8 through the Gap between the Seat Section 11 and the Valve Body 4]
In the diagnosis using "amount of leakage of nitrogen gas 19 that leaks from the bonnet portion 8 through the gap between the seat portion 11 and the valve body 4 to the flow path 3" which is a characteristic amount for determining the malfunction of the sluice valve 1, Based on the change in pressure difference between the supply pressure of the nitrogen gas 19 supplied from the nitrogen gas supply equipment 90 to the bonnet portion 8 and the pressure of the nitrogen gas 19 inside the bonnet portion 8, the seat portion 11 and the valve body 4 are By estimating the amount of leakage of the nitrogen gas 19 leaking from the gap between and, the malfunction of the seat portion 11 is diagnosed. There is a correlation between the pressure difference and the leakage amount of the nitrogen gas 19 leaking from the bonnet portion 8. The larger the pressure difference, the larger the leakage amount of the nitrogen gas 19. Therefore, by detecting the magnitude of the pressure difference, the magnitude of the leakage amount of the nitrogen gas 19 can be estimated.

Specifically, when the valve body 4 is fully closed (when the valve body 4 is in the fully closed position S), the supply pressure of the nitrogen gas 19 supplied from the nitrogen gas supply equipment 90 to the bonnet portion 8 and the bonnet portion 8 The pressure difference between the pressure of the nitrogen gas 19 and the inside of the nitrogen gas is calculated, and whether or not the calculated pressure difference is equal to or larger than a predetermined pressure difference is calculated. Here, the predetermined pressure difference is a value calculated by the pressure difference when a defect (abnormality) of the seat portion 11 has occurred in the past.

When the calculated pressure difference is equal to or more than the predetermined pressure difference, the “leak amount of the nitrogen gas 19 that leaks from the bonnet portion 8 through the gap between the seat portion 11 and the valve body 4 to the flow path 3” is predetermined. It is estimated that the leak amount is equal to or more than the leak amount. That is, it is diagnosed that the seat portion 11 is defective. Here, the predetermined leak amount is a value calculated from the leak amount of the nitrogen gas 19 estimated from the pressure difference when a defect (abnormality) of the seat portion 11 has occurred in the past. On the other hand, when the calculated pressure difference is smaller than the predetermined pressure difference, “the leakage amount of the nitrogen gas 19 that leaks from the bonnet portion 8 through the gap between the seat portion 11 and the valve body 4 to the flow path 3” Is estimated to be less than a predetermined leakage amount, and it is diagnosed that the seat portion 11 has no defect.

As described above, the characteristic amount for determining the malfunction of the sluice valve 1 is the “amount of leakage of the nitrogen gas 19 that leaks from the bonnet portion 8 through the gap between the seat portion 11 and the valve body 4 into the flow path 3”. The diagnosis used is based on the change in the pressure difference between the supply pressure of the nitrogen gas 19 supplied from the nitrogen gas supply equipment 90 to the bonnet part 8 and the pressure of the nitrogen gas 19 inside the bonnet part 8, based on the change in pressure. This is performed by estimating the amount of leakage of the nitrogen gas 19 that leaks from the sheet to the flow path 3 through the sheet portion 11.

According to the present embodiment, since the malfunction of the sluice valve 1 is diagnosed based on the change in the operating pressure of the actuating device 6 for moving the valve body 4 in the opening/closing direction, the sluice valve 1 can be operated without stopping the operation of the sluice valve 1. The condition of the valve 1 can be determined. Furthermore, since the state of the sluice valve 1 can be determined without stopping the operation of the sluice valve 1, when the seat part 11 and the guide rail 20 are inspected or replaced in equipment that simultaneously operates a plurality of sluice valves 1, The operation of the sluice valve 1 can be stopped according to the state of the sluice valve 1, and the operation efficiency of the sluice valve 1 in the entire equipment can be improved.

In the present embodiment, the thresholds (T1, T2, T3) for determining the malfunction of the sluice valve 1 are set, and the malfunction of the sluice valve 1 is diagnosed based on the threshold value. However, the present invention is not limited to this. The operating pressure of the hydraulic cylinder 25 (differential pressure between the rod-side operating pressure and the head-side operating pressure) detected in each of the plurality of sluice valves 1 or each of the plurality of sluice valves 1 is calculated. The malfunction of the sluice valve 1 may be diagnosed by relatively comparing the friction coefficient of the valve element 4 in the seat sliding section between the individual sluice valves 1.

In the present embodiment, the supply pressure sensor 91 is provided in the detection device 41, and the pressure value detected by the supply pressure sensor 91 is used to determine the leakage amount of the nitrogen gas 19 leaking from the gap between the seat portion 11 and the valve body 4. Although it is estimated, the present invention is not limited to this configuration, the supply pressure sensor 91 is not provided in the detection device 41, and the detection device 41 supplies the data of the supply pressure of the nitrogen gas 19 provided from the nitrogen gas supply facility 90. It may be configured to receive only (pressure value).

1 Gate Valve 2 Valve Box 3 Flow Path 4 Valve Body 6 Actuator 7 Valve Box Body 8 Bonnet 11 Seat 19 Nitrogen Gas (Purge Gas)
20 Guide rail (guide member)
A Open direction B Close direction O Open position S Closed position

Claims (8)

A guide member for guiding the valve body that opens and closes the flow path in the opening and closing direction is provided in the valve box,
The valve box has a valve box body portion having a flow path and a bonnet portion,
The valve body moves in the opening/closing direction while slidingly contacting the guide member by a fluid pressure type operating device, penetrates into the valve box main body at the closed position to block the flow path, and from the valve box main body to the inside of the bonnet section at the open position. A method of diagnosing a sluice valve for diagnosing a malfunction of the sluice valve that retreats to
Detecting the operating pressure of the operating device for moving the valve element in the opening and closing direction,
A method of diagnosing a sluice valve, which comprises diagnosing a malfunction of the sluice valve based on a detected change in operating pressure. Detecting the operating pressure of the actuator,
The diagnosing method of the sluice valve according to claim 1, wherein the surface condition of the guide member is diagnosed based on a change in the detected operating pressure. Detecting the operating pressure of the actuator,
The diagnosing method of the sluice valve according to claim 1 or 2, wherein the attachment state of the guide member attached to the valve box is diagnosed based on a change in the detected operating pressure. Detecting the operating pressure of the actuator when moving the valve element from the closed position to the open position,
The diagnosing method of the sluice valve according to any one of claims 1 to 3, wherein a malfunction of a seat portion of the sluice valve is diagnosed based on a change in the detected operating pressure. When the valve body is in the closed position, the pressure difference between the supply pressure of the purge gas supplied to the bonnet portion and the pressure of the purge gas inside the bonnet portion is detected,
Based on the change in the detected pressure difference, from the bonnet portion, the leakage amount of the purge gas that leaks into the flow path through the gap between the seat portion and the valve body is estimated,
The diagnosing method of the sluice valve according to any one of claims 1 to 4, wherein a malfunction of the seat portion is diagnosed on the basis of the estimated leak amount of the purge gas. Detecting the operating pressure of the operating device in a section in which the valve body moves in the opening/closing direction while slidingly contacting the guide member,
6. The surface condition of the guide member and the mounting condition of the guide member mounted to the valve box are diagnosed based on the detected change in the working pressure. The method for diagnosing the sluice valve is described in item 1. Detecting the operating pressure of the operating device in the section in which the valve body moves in the opening and closing direction while slidingly contacting the seat portion,
The method for diagnosing a sluice valve according to any one of claims 1 to 6, wherein the surface state of the seat portion is diagnosed based on the detected change in the operating pressure. A guide member for guiding the valve body that opens and closes the flow path in the opening and closing direction is provided in the valve box,
The valve box has a valve box body portion having a flow path and a bonnet portion,
The valve body moves in the opening/closing direction while slidingly contacting the guide member by a fluid pressure type operating device, penetrates into the valve box main body at the closed position to block the flow path, and from the valve box main body to the inside of the bonnet section at the open position. Is a sluice valve diagnostic system for diagnosing malfunctions of the sluice valve that moves
An operating pressure detecting device for detecting an operating pressure of the operating device for moving the valve element in the opening/closing direction;
A sluice valve diagnostic device that diagnoses a malfunction of the sluice valve based on a change in the working pressure detected by the working pressure detection device,
A sluice valve diagnostic system comprising:

Images