JPH059609B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an abnormality diagnosis device for a hydraulic valve drive device such as a steam turbine governor of a power generation plant.
In particular, the present invention relates to an abnormality diagnosis device for hydraulic valve drive devices suitable for steam turbine governors in nuclear power plants where patrols are difficult and reliability is extremely important.

[Background of the invention]

As conventional hydraulic valve drive devices, for example, steam turbine governors in power plants use a variety of main steam stop valves (MSV), main steam control valves (SCV), intermediate check valves (ISV), intermediate control valves (IV), etc. It consists of several valves, and each type of valve also constitutes a plurality of valve groups. Conventionally, as a method for diagnosing abnormalities in hydraulic valve drive devices for these valves, in order to know the operating status of these valves, a valve opening/closing test is performed on each valve one by one every day or on certain limited days. The operator visually monitors the condition.

However, conventional methods for diagnosing abnormalities in hydraulic valve drive devices require a great deal of labor and time because they rely on the operator's intuition, and they are difficult to diagnose when an obvious abnormality occurs. However, it has been impossible to detect the symptoms and take countermeasures. Furthermore, it is impossible to know in the instrumentation room whether there is oil leakage in the hydraulic system or the degree of wear and tear on the hydraulic equipment.Especially in cases where the equipment is exposed to radiation, such as in nuclear power plants, major valves are frequently operated. Since it is impossible to patrol the area by hand, there was a strong desire to develop a method to predict oil leaks before they occur.

[Purpose of the invention]

In view of the above points, an object of the present invention is to provide an efficient and reliable abnormality diagnosis device for a hydraulic valve drive device that can predict signs of failure in advance.

[Summary of the invention]

The present invention combines two diagnostic functions: constant diagnosis and periodic diagnosis, and the constant diagnosis uses a leak sensor to constantly monitor oil leaks in the hydraulic system.
An abnormality diagnosis device for hydraulic valve drive equipment that uses pressure sensors and displacement sensors to conduct valve opening/closing tests to check equipment wear and operating status during periodic diagnostics, and makes it possible to quickly and accurately identify abnormal equipment by combining these tests. It is.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 7.

First of all, FIG. 1 shows a steam turbine of a steam turbine plant for a nuclear power plant using a BWR as an example of a hydraulic valve drive system to which the present invention is applied.
FIG. 2 is a schematic overall configuration diagram illustrating a governor. In Figure 1, the power reactor BWR and high pressure turbine
In a plant consisting of HP, low-pressure turbine LP, and generator GEN, the steam turbine governor is used to control the speed of the steam turbine, and the main steam stop valve MSV is used to control the steam flow rate to the steam turbine or to open and close the flow path. , main steam control valve SCV, intermediate steam stop valve ISV, intermediate control valve IV, etc., and each of them is composed of a plurality of valve groups as shown in the figure. In addition to these valve bodies, there is also a hydraulic system (not shown) that supplies pressure oil to these valve bodies, and a valve driving device such as a control pack that controls their movements.

FIG. 2 shows an abnormality diagnosis system for a hydraulic valve drive device according to the present invention for a main steam stop valve MSV, which will be explained below as an example of a typical operation valve among all the control valves shown in FIG. 1 that are the object of the present invention. FIG. 2 is a partial configuration diagram showing one embodiment of the present invention. In Figure 2, 1 is the main steam stop valve
The main steam inlet of the MSV main body, 2 is also the outlet, 3
is a poppet, 4 is a valve seat, 5 is a stem of poppet 3, 6 is a spring, 7 is a hydraulic cylinder, 8 is a disc valve, 9 is a valve seat, 10 is a spring, 11 is a lower pressure chamber,
12 is a dump room. 13 is the main steam stop valve
The servo valves of the MSV's hydraulic valve drive device include a shut-off valve 14, a quick-closing solenoid valve 15, and a pressure oil device 16. Furthermore, 17, 18, 19 are respective contacts during periodic diagnosis of the abnormality diagnosis device of the hydraulic valve drive device;
20 is a displacement sensor for the stroke S of the hydraulic cylinder 7; 21 and 22 are the lower pressure chamber 11 and the dump chamber 12
are pressure sensors for respective pressures P ₁ and P ₂ .

With this configuration, the main steam generated in the RWR can flow from the main steam inlet 1 to the outlet 2 of the MSV, and the valve seat 4
The flow path is opened and closed by controlling the position of the poppet 3 relative to the flow path. In order to control the position of the poppet 3, the stem 5 of the poppet 3 is directly connected to a hydraulic cylinder 7 for driving the valve, and is always pushed downward by a spring 6. On the other hand, pressure oil from a pressure oil device 16 is supplied to and discharged from a pressure oil device 16 by a servo valve 13 of a valve driving device to control the lower pressure chamber 11 having a pressure _P1 . moreover
When an MSV quick-closing command comes, this command signal is given to the quick-closing solenoid valve 15, which causes the dump chamber 12
Since the pressure oil of pressure P ₂ is removed, the disc valve 8 supported by the spring 10 releases the pressure oil of the lower pressure chamber 11.
As a result of being pushed downward against the valve seat 9 by P ₁ ,
The lower pressure chamber 11 and the dump chamber 12 communicate with each other, and the hydraulic cylinder 7 performs a quick closing operation. At this time, the shut-off valve 14 shuts off the flow of pressure oil to the servo valve 13 with a certain time constant when the command of the quick-closing solenoid valve 15 is received, and with a certain time constant when the command of the quick-closing solenoid valve 15 is terminated. It serves to communicate the flow of pressure oil to the servo valve 13. In the periodic diagnosis of such an abnormality diagnosis device for a hydraulic valve drive device, in addition to the contacts 17 to 18 during the periodic diagnosis and the displacement sensor 20 for the stroke S of the hydraulic cylinder 7, the lower pressure chamber 1
1 and the pressure sensors 21 and 22 that detect the pressures P ₁ and P ₂ of the dump chamber 12, the pressure P (P ₁ , P ₂ ) as well as the stroke S vs. time t characteristic etc. are introduced.
The stroke S characteristic is also determined, and this determines whether the abnormality of the servo valve 13 is caused when the operation of the hydraulic cylinder 7 becomes abnormal, as will be described later, or whether it is due to a stay such as the stem 5 directly connected to the hydraulic cylinder 13. It becomes possible to make a determination.

FIG. 3 is an abnormality diagnosis flowchart showing an embodiment of an abnormality diagnosis apparatus for a hydraulic valve drive device according to the present invention. In Fig. 3, the diagnostic function is classified into two types: continuous diagnosis and periodic diagnosis. In continuous diagnosis, the test switch is turned off and at least a group of leak sensors as described later is used to check the valve body, valve drive device, and its hydraulic system, etc. In order to constantly monitor oil leakage, and preferably to diagnose the condition of the hydraulic oil in the hydraulic system as a constant monitoring item, ferrography using known means is added to measure the amount of metal powder in the oil and its viscosity distribution, While displaying the plant and displaying leak abnormalities, regular diagnosis uses contacts 17 to 19, displacement sensor 20, pressure sensors 21, 22, etc. only when the test switch is turned on.
Testing the opening/closing operation of a valve drive device such as an MSV is preferably carried out using test patterns such as gradual closing, sudden closing, opening preparation operation, and gradual opening described below, diagnosing abnormalities, and displaying the resulting test data by known means. It is something.

FIGS. 4a and 4b are perspective external views and circuit configuration diagrams of a leak sensor that utilizes changes in thermal conductivity for constant diagnosis, showing an embodiment of the abnormality diagnosis apparatus for a hydraulic valve drive device according to the present invention. In Figure 4a, 23
is a leak sensor, 24 is its ceramic substrate, 2
5 and 26 are thin insulation materials, 27 is thick film printed W
(Tungsten) conductive wire 28 is a lead wire.
With this configuration, the oil leaking fluid shown by the arrow is outputted by utilizing the change in resistance of the W conductor due to a sudden change in thermal conductivity. As shown in FIG. 4b, a Wheatstone bridge is formed by the leak sensor 23 having a resistor R _W and resistors R ₂ , R ₃ , and R ₄ , and a constant current I is applied to the leak sensor 23 via the transistor Tr.
is constantly flowing, and the unbalanced voltage due to the change in resistance R _W caused by the sudden change in thermal conductivity due to contact with the oil leak fluid shown by the arrow is applied to the operational amplifier 29.
This system detects oil leakage by detecting fluid leakage. The leak sensor 23 is installed at a leak diagnosis location such as the valve body, the valve driving device, the control pack, and their hydraulic system.

FIG. 5 is a diagram of a valve opening/closing test pattern for periodic diagnosis showing an embodiment of the abnormality diagnosis device for a hydraulic valve drive device according to the present invention. In Figure 5, the modes of the valve opening/closing test pattern for periodic diagnosis are as shown in the diagram: gradual closing (MODE1), sudden closing (MODE2), (opening preparation operation),
The operation time t (stroke time t of the hydraulic cylinder 7) and the operating pressure P (the pressure in the lower pressure chamber 11 of the hydraulic cylinder 7) are divided into three modes: gradual opening (MODE3). P ₁ ), (pressure P ₂ of the dump chamber 12), valve stroke S (stroke S of the hydraulic cylinder 7), etc. are stored in the storage means, and these normal pattern data and test data obtained at each periodic diagnosis are stored. Compare with
The time deviation Δt, pressure deviation ΔP, stroke deviation ΔS, and other deviation values are monitored to see if they each exceed a certain value (tolerance value, threshold value), and if the deviation value is below a certain value, it is determined to be normal. If the deviation value is above a certain value, it is determined to be abnormal and an alarm is issued. For example, a bit pattern is formed for time deviation Δt, pressure deviation ΔP, stroke deviation ΔS, etc., and each deviation value is constant. If the deviation value is normal or less, the corresponding bit is set to ``0'', for example, but if the deviation value exceeds a certain value and is abnormal, it is preferable to display the corresponding bit as ``1'' in the table. It becomes possible to identify abnormal devices (abnormal locations) such as

FIGS. 6a and 6b are diagrams illustrating an example of a bit pattern in which abnormality determination results of valve opening/closing test data of periodic diagnosis are displayed in a table, showing an embodiment of the abnormality diagnosis apparatus for a hydraulic valve driving device according to the present invention. Figure 6 is an example of the bit pattern for the gradual closing (MODE1) of the valve opening/closing test pattern in Figure 5, and the bit patterns for the time deviation Δt, pressure deviation ΔP, and stroke deviation ΔS in Figure 6a.
The corresponding bit of the pattern is “1”, “0”, “1”
In this case, the pressure deviation ΔP is below a certain value (tolerable value), but the time deviation Δt and stroke deviation ΔS are larger than the certain values, so there is an abnormality in the flow characteristics of the servo valve 13 in the hydraulic system. Since this indicates that the servo valve 13 has occurred, it is determined that the servo valve 13 is abnormal.
Also, the bit pattern in FIG. 6b is "1",
When the values are "1" and "1", in addition to the time deviation Δt and stroke deviation ΔS, the pressure deviation ΔP has also become larger than a certain level, so the cylinder system of the hydraulic cylinder 7 is stuck and the movement is smooth. Since it shows that it has disappeared, it can be determined that it is a sign of cylinder system stuckness. In this way, it is possible to separate and determine abnormalities in the system between the servo valve 13 and the hydraulic cylinder 7 from the bit pattern table of the gradual closing (MODE 1) of the valve opening/closing test pattern.

By using the same bit pattern table as shown in Fig. 6a and b for the valve opening/closing test pattern, such as quick closing (MODE2), it is possible to
4. Abnormalities in the quick-closing solenoid valve 15, etc. can also be isolated and determined.

FIG. 7 is a block diagram of a hardware configuration showing an embodiment of an abnormality diagnosis device for a hydraulic valve drive device according to the present invention. In FIG. 7, 30 indicates the diagnosis target equipment side of the hydraulic valve valve drive device, 31 indicates the instrumentation room (central operation room) side of the abnormality diagnosis device, and 32
33 is the valve drive device (control pack), and 33 is due to contact between the valve body on the equipment side, the valve drive device (control pack), and the oil leakage fluid installed at the oil leak diagnosis location for constant diagnosis of the hydraulic system. A leak sensor (and its amplifier) for constant monitoring using an element that utilizes changes in thermal conductivity, etc., is installed on the equipment side for constantly diagnosing the condition of the hydraulic oil and detects the amount of metal powder in the oil. A ferrograph for measuring the viscosity distribution, 35 a signal transmission device on the equipment side that collects data signals from the leak sensor 33 and a ferrograph 34, and 36 a transmission line for transmitting data signals from the signal transmission device 35 to the instrumentation room side. (e.g. optical fiber). Further, 37 is a valve opening/closing test panel for performing periodic diagnosis on the instrumentation room side of the abnormality diagnosis device, and 38 is a transmission line (optical fiber) 3.
4 data signal and time (stroke time t) from the valve drive device 32, pressure (cylinder chamber pressure P),
A signal conversion device is installed in the instrumentation room side that receives analog signals such as displacement (stroke S) and inputs test switch signals and solenoid valve signals from the test board 37, 39 is a microcomputer that performs information processing, and 40 is a An output display device for displaying images and voice responses, 41 and 42 are signal lines, 43 is a transmission line, and 44 and 45 are loop transmission lines.

With this configuration, as shown in the abnormality diagnosis flowchart in FIG. (and amplifier) 33, ferrograph 34, etc., to the signal transmission device 35 on the equipment side,
It is sent to the instrumentation room side via the transmission line (optical fiber) 36. Then, the signal converter 38 on the instrumentation room side receives these data signals and sends them to the microcomputer 39 via the loop transmission line 44, the microcomputer 39 processes the data, and displays the plant results and indicates leak abnormalities. The location display etc. is sent to the output display device 40 via the loop transmission line 45.
Display CRT image or provide voice response. Further, in the periodic diagnosis when the test switch of the test panel 37 is turned on, the valve driving device 32 receives a control signal from the test panel 37 via the signal line 41 and starts.
For example, gradual closing of variable opening/closing test pattern (MODE1),
Rapid closing (MODE2), opening preparation operation, gradual opening (MODE3)
Valve opening/closing tests such as valve opening/closing tests are performed, and the stroke time t of the valve (hydraulic cylinder) from contacts 17 to 19, pressure sensors 21, 22, displacement sensor 20, etc. during periodic diagnosis, pressure P in the hydraulic cylinder pressure chamber, valve (hydraulic Analog signals such as the stroke S of the cylinder) are sent to the instrumentation room side via the signal line 42. Then, the signal conversion device 38 on the instrumentation room side receives the test switch signal and the solenoid valve signal for sudden closing from the test panel 37 via the transmission line 43, and when it receives the analog signal, it converts it into a signal. and sends it to the microcomputer 39, and the microcomputer 3
In step 9, the data is subjected to arithmetic processing, and the normal pattern data stored in the built-in memory is compared with this test data, and the deviation values of the time deviation Δt, pressure deviation ΔP, stroke deviation, etc. are all constant. It determines whether the value (tolerance value, threshold value) is exceeded, and if the deviation value is below a certain value, it is judged as normal, but if the deviation value is above a certain value, it is judged as abnormal and the output display device 40, for example, generates an alarm, creates bit patterns for time deviation Δt, pressure deviation ΔP, stroke deviation ΔS, etc., and sets the corresponding bit to “0” if each deviation value is below a certain value. If the deviation value is above a certain value, the corresponding bit is set to "1" and this bit pattern is displayed on the output display device 40, and the diagnosis result is displayed on a CRT image or as an audio response. , This allows the abnormal device (abnormal location) to be isolated and confirmed.

As described above, according to this embodiment, two diagnostic functions, constant diagnosis and periodic diagnosis, are combined in abnormality diagnosis of hydraulic valve drive devices such as steam turbines and governors in power plants. While we constantly monitor the condition of the hydraulic oil using leakage and ferrography, we also conduct valve opening/closing tests using pressure sensors and displacement sensors to check equipment wear and operating conditions using valve opening/closing test patterns, and make judgments based on combinations of these tests. This makes it possible to conduct online diagnostics such as functional confirmation of component equipment and early and accurate isolation of abnormal equipment (abnormal location), making it possible to predict accidents by early detection of abnormalities in power plants, especially steam turbine governors in nuclear power plants. This has the effect of improving the reliability of the power plant by making it possible to prevent and prevent damage.

〔Effect of the invention〕

As described above, according to the present invention, abnormality diagnosis of a hydraulic valve drive device can be performed efficiently and accurately, and there are effects such as making it possible to prevent equipment accidents before they occur.

[Brief explanation of the drawing]

FIG. 1 shows a steam turbine of a nuclear power plant illustrating a hydraulic valve drive device to which the present invention is applied.
FIG. 2 is a schematic overall configuration diagram of the governor, and FIG. 2 is a partial configuration diagram showing an embodiment of an abnormality diagnosis device for a hydraulic valve drive device according to the present invention. Figure 3 is an abnormality diagnosis flowchart, Figures 4a and 4b are perspective external views and circuit configuration diagrams of the leak sensor, Figure 5 is a valve opening/closing test pattern diagram, and Figures 6a and b are valves. FIG. 7, which is an example of each bit pattern of the opening/closing test results, is also a hardware configuration block diagram. 1... Main steam inlet of main steam stop valve (MSV),
2...exit, 3...poppet, 4...valve seat, 5...
...Stem, 6...Spring, 7...Hydraulic cylinder, 8
...Disk valve, 9...Valve seat, 10...Spring, 1
1... Lower pressure chamber, 12... Dump chamber, 13...
Servo valve of valve drive device, 14...Shut-off valve, 15...Solenoid valve, 16...Hydraulic system, 17,
18, 19... Contact during periodic diagnosis, 20... Displacement sensor, 21, 22... Pressure sensor, 23... Leak sensor, 24... Ceramic substrate, 25, 2
6...Insulating material, 27...Thick film printed W wire, 28...Lead wire, 29...Differential amplifier, 30...Equipment (side), 31...Instrumentation room (side), 32...Valve drive Device, 33...Leak sensor, 34...Ferography, 35...Signal transmission device, 36...Transmission line (optical fiber), 37...Valve opening/closing test panel, 38...
...Signal converter, 39...Microcomputer, 40...Output display device, 41, 42...Signal line, 43...Transmission line, 44, 45...Loop transmission line.

Claims (1)

[Scope of Claims] 1. Comprising a constant diagnostic device that constantly performs abnormality diagnosis of a hydraulic valve drive device that controls the flow rate of fluid or drives a valve that opens and closes a flow path, and a periodic diagnostic device that periodically performs abnormality diagnosis. The constant diagnosis means includes at least means for constantly monitoring oil leaks in the hydraulic system of the valve drive device using a leak sensor, and the periodic diagnosis means periodically performs valve opening/closing tests and determines the valve and valve drive based on the data. An abnormality diagnosis device for a hydraulic valve drive device comprising means for diagnosing an abnormality in the device. 2. The abnormality diagnosis device for a hydraulic valve drive device according to claim 1, wherein the leak sensor is an element that utilizes a change in electrical resistance due to a change in thermal conductivity due to oil leakage. 3. The hydraulic valve according to claim 1, wherein the constant diagnosis means includes means for diagnosing the state of the hydraulic oil by means of ferrography, which measures the amount of metal powder in the hydraulic oil of the valve drive device and its viscosity distribution. Drive unit abnormality diagnosis device. 4. The periodic diagnosis means uses a displacement sensor that measures the stroke of the hydraulic cylinder of the valve drive device and a pressure sensor that measures the pressure in the pressure chamber of the hydraulic cylinder to determine the hydraulic cylinder pressure vs. stroke characteristics and stroke vs. time of the valve opening/closing test. An abnormality diagnosing device for a hydraulic valve drive device according to claim 1, comprising means for determining characteristics and comparing these test data with normal data to diagnose an abnormality. 5 The periodic diagnosis means determines the hydraulic cylinder stroke time, cylinder pressure, and cylinder stroke characteristics for each mode of gradual closing, sudden closing, and gradual opening of the valve opening/closing test pattern, and converts these test data into normal data stored in itself. If the stroke time deviation value, pressure deviation value, and stroke deviation value for each mode are below each allowable value, the operation is determined to be normal, and if they are above the allowable value, the operation is judged to be abnormal, and the latter is determined as necessary. 5. The abnormality diagnosis device for a hydraulic valve drive device according to claim 4, further comprising a means for issuing an alarm if the abnormality is detected. 6. The periodic diagnostic means sets the corresponding bit to "0" when the stroke time deviation value, pressure deviation value, and stroke deviation value are below each allowable value (normal), and when they are above the allowable value (abnormal). 6. An abnormality diagnosis device for a hydraulic valve drive device according to claim 5, further comprising means for forming a bit pattern of "1" and displaying the bit pattern in a table. 7. The periodic diagnostic means detects the servo of the valve driving device when the stroke time deviation value is above the allowable value, the pressure deviation value is below the allowable value, and the stroke deviation value is above the allowable value in the valve opening/closing test in the gradual closing mode. It is determined that the servo valve is abnormal among the valve and hydraulic cylinder system, and if the stroke time deviation value is above the allowable value, the pressure deviation value is above the allowable value, and the stroke deviation value is above the allowable value, the hydraulic cylinder system is judged to be abnormal ( 7. An abnormality diagnosis device for a hydraulic valve drive device according to claim 5 or 6, further comprising a means for determining whether the valve is stuck or not. 8 The periodic diagnosis means detects the shut-off valve of the valve drive device depending on whether the stroke time deviation value, pressure deviation value, and stroke deviation value in the valve opening/closing test in the quick closing mode are below or above each allowable value. 7. An abnormality diagnosis device for a hydraulic valve drive device according to claim 5 or 6, further comprising means for separately determining whether the quick-closing solenoid valve is normal or abnormal. 9 The above-mentioned continuous diagnosis means installs the above-mentioned leak sensor, ferrograph, etc. on the side of the valve to be diagnosed and the valve drive device, and transmits data signals from them via a transmission path such as an optical fiber from a signal transmission device installed on the same side. The periodic diagnosis means transmits a test control signal to the valve drive device from the valve opening/closing test panel and the displacement sensor and pressure sensor of the valve drive device. The data signal and the analog signal are inputted to the microcomputer through the signal converter, and the data signal and the analog signal are input to the microcomputer through the signal converter to detect an abnormality. 9. An abnormality diagnosis device for a hydraulic valve drive device according to any one of claims 1 to 8, further comprising means for performing a diagnosis and displaying the results as an image on an output display device or as an audio response.