JPH03148018A - Controlling apparatus for preventing abnormal flow of liquid - Google Patents

Abstract

PURPOSE:To prevent cavitation by outputting a valve driving signal to a valve driving apparatus in response to an output signal from an abnormal flow detecting circuit, and providing a controller for controlling the opening degree of a valve. CONSTITUTION:Detecting data of pressures before and after a valve 2 which are respectively detected by pressure sensors 3, 4 are input to a valve driving apparatus 20. Detecting data of a flow rate downstream the valve 2 detected by a flow rate sensor 5 is input to the apparatus 20 and also to a controller 30. Vibrating data of a piping 1 detected by an acceleration sensor 6 is input to an abnormal flow detecting circuit 13. If an abnormality is detected in the flow of a fluid, the circuit 13 generates an abnormal flow detecting signal to the controller 30. Upon receipt of the signal from the circuit 13, the controller 30 generates a signal to indicate the opening/closing amount of the valve 2 to the apparatus 20. Moreover, a pressuring pump 7 adjusts the supplying pressure to the flow running in the piping 1 in response to the command from the controller 30.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to fluid pumping equipment used in plants, etc., and in particular, when an abnormal flow of fluid flowing in a pipe such as a cavity pipe is detected, The present invention relates to an abnormal fluid flow prevention control device for normalizing the flow by adjusting equipment such as valves.

[Conventional technology]

Generally, when a liquid flows through a channel system, the flow velocity and pressure of the liquid flowing through the channel system vary at various parts within the pipe.

When the pressure at a certain point in the flow path system is about to drop below the saturated vapor pressure at the temperature of the liquid at that time, the liquid boils instantaneously and creates bubbles, which immediately rise to a higher pressure area. Cavitation, a phenomenon in which particles are carried away and disappear, may occur. Then, the channel system generates high impact pressure at the moment the bubbles disappear, which causes damage to parts such as piping and valves of the channel system. In addition, bubbles caused by cavitation repeatedly generate and disappear one after another, resulting in noise and vibration. The frequency of the vibrations is quite high, and cough vibrations can often be heard as a metallic sound.

In addition, cavitation not only damages the inner surface of pipes, but also reduces the performance of equipment connected to the pipes. Furthermore, when noise and vibration become large, cavitation can cause damage to pipe fittings, damaged pipes, valves, etc. This can lead to water leakage and equipment damage.

Conventionally, measures to prevent the above phenomenon have been to design piping systems so that the liquid flowing inside the pipes does not have high-speed, low-pressure regions, and to polish the flowing water surface in the pipes as smooth as possible to prevent cavitation. Areas where corrosion is likely to occur should be covered in advance with a corrosion-resistant material, such as 18-8 stainless steel, or repaired with a similar material on damaged areas of the water flow surface found during periodic inspections. Measures such as these are being taken. Or special stainless cast steel, such as 13C
It is known to use a device using ~4Ni.

However, even if the surface of the flowing water is polished as smooth as possible to prevent the occurrence of cavities, there is a limit as the area to be polished is the inner surface of the pipe and the work must be done manually. be. Furthermore, it is said that cavitation is likely to occur at the outlet of a valve or the bent part of a pipe, so it is possible to build up 188 stainless steel in advance using the method described above in areas that are likely to be damaged. However, cavitation does not always occur in the same location, and damage can occur over a wide range of locations. Therefore, it is necessary to perform overlaying over a certain range, which becomes a factor in high costs. Furthermore, it is not possible to make all the equipment, joints, and pipes from special stainless steel cast steel because of the high cost.

Furthermore, cavitation is an unavoidable phenomenon due to the fact that liquid is pumped through the flow path system, and periodic inspection work is essential. However, the current periodic inspection work only determines the timing of its implementation based on experience, and does not involve confirming the strength of cavitation numerically or determining the cumulative amount of time cavitation has occurred. For this reason, inspection work is not necessarily carried out at the optimal time.

On the other hand, as a device for preventing cavitation occurring in a fluid circuit, conventionally, for example, Japanese Patent Laid-Open No. 61-25
A water flow rate prevention device for a gas water heater described in Japanese Patent No. 2449 is known. The water flow rate prevention device of the gas water heater is
In order to prevent cavitation that occurs in the valve inserted in the fluid circuit of a gas instantaneous water heater, the flow rate passing through the valve can be adjusted. A pressure valve is provided to increase the pressure on the downstream side of the valve seat of the control valve, and when the control valve is wide open, the opening of the back pressure valve is widened. When the amount of water to be used is small and the pressure of tap water is high, that is, when the opening degree of the control valve is small, the back pressure valve closes and increases the water flow resistance (thus increasing the pressure downstream of the control valve). If the flow rate of the heat exchanger is high and the pressure of tap water is low, open the back pressure valve to allow a sufficient flow rate to suppress cavitation. This was prevented.

[Problem to be solved by the invention]

However, the water flow prevention device for gas water heaters disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 61-252449 only prevents cavitation within the valve, and does not attempt to prevent cavitation within the pipe. .

Moreover, when applied to liquid pumping equipment where a large number of valves are used, such as in wastewater treatment plants, each valve must be manufactured according to the location where it will be installed.
Moreover, it is impossible to judge whether or not the valve really functions effectively until after manufacturing and installing it.

By the way, the present applicant has developed an electric actuator for driving a valve with a built-in electronic control device in Japanese Patent Application Laid-Open No. 62-292978. This electric actuator for driving valves with a built-in electronic control device is directly connected to the central control device using a serial data transmission system to exchange information and enable distributed processing, and is a part of the valve opening control system. The arithmetic circuit for handling this is integrated into the electric actuator, and a solid state relay is used in place of the electromagnetic relay. The valve drive electric actuator with a built-in electronic control device can not only directly control the valve using the serial data signal (digital signal) of the controller on the central control device side, but also This makes it possible to process and control wIIll due to environmental changes such as flow rate and temperature using the arithmetic circuit inside the valve drive electric actuator as needed without sending a signal to the center. In addition to being smaller and lighter, the structure also reduces the burden on the central controller, making it possible to perform systematic control of the valve opening.

The purpose of this invention is to solve the above problems,
By numerically capturing the occurrence of abnormal flow such as cavitation in the flow path system such as piping and valves, and feeding back the numerical data to equipment, it is possible to detect when abnormal flow occurs in the flow path system or when abnormal flow occurs. For example, if the valve drive device such as the electric valve drive actuator with a built-in electronic control device is used to control the opening degree of the valve installed in the flow path system, the flow in the flow path system can be controlled. An abnormal fluid flow prevention control device that is configured to return to normal flow state without interrupting the flow, prevent abnormal flow, and, in some cases, make it possible to notify the optimal time to inspect the flow path system. The goal is to provide the following.

[Means to solve the problem]

In order to achieve the above object, the present invention is configured as follows. That is, the present invention includes a valve provided in a fluid flow path system, a valve driving device that adjusts the opening degree of the valve, an acceleration sensor provided in the fluid wave path system, and an abnormality detected in response to a detection signal from the acceleration sensor. an abnormal flow detection circuit that outputs a signal in a frequency band of flow generation; a controller that outputs a valve drive signal to the valve drive device in response to the output signal from the abnormal flow detection circuit to control the opening degree of the valve; The present invention relates to an abnormal fluid flow prevention control device comprising:

Further, in this fluid abnormal flow prevention control device, the abnormal flow detection circuit includes an amplifier that amplifies the signal from the acceleration sensor, a filter that allows only a signal of a specific frequency to pass among the signals from the amplifier, and an abnormal flow detection circuit. It consists of a multiplexer that passes only the current signal, and an A/D converter that converts the signal from the multiplexer from analog to digital.

Further, in this fluid abnormal flow prevention control device, the controller includes an amplitude detecting means for detecting the amplitude of the abnormal flow detection signal inputted from the abnormal flow detection circuit, and an amplitude detecting means for detecting the amplitude of the abnormal flow detection signal inputted from the abnormal flow detection circuit, and comparing the amplitude at the current time with the amplitude before a predetermined time. It consists of an amplitude comparison means and a flow rate setting means for setting the flow rate to be commanded to the valve driving device based on the increase/decrease in the amplitude, and also has a display device that displays the cumulative time of occurrence of abnormal flow and the cumulative number of vibrations. be.

Further, in this fluid abnormal flow prevention control device, the display device includes an amplitude detection means for detecting the amplitude of the abnormal flow detection signal inputted from the abnormal flow detection circuit, and an amplitude detection means for detecting the amplitude of the abnormal flow detection signal inputted from the abnormal flow detection circuit, and an amplitude detection means for detecting the amplitude of the abnormal flow detection signal input from the abnormal flow detection circuit. An amplitude recovery counting means for counting the cumulative value, a timer for measuring the duration when abnormal flow occurs, and the cumulative time from the past by adding the duration transmitted from the timer when the abnormal flow detection signal is no longer input. a recorder for storing the cumulative time sent from the cumulative time calculating means and the cumulative number of vibrations sent from the vibration frequency counting means;
and a display for displaying the cumulative time and the cumulative number of vibrations as necessary.

Furthermore, in this fluid abnormal flow prevention control device, the controller includes a pressure pump control device that controls the supply pressure of the pressure pump in response to a signal that does not prevent the abnormal flow even after a predetermined period of time has elapsed. Moreover, it has a pressurizing pump control device for ensuring a constant amount of work in response to increases and decreases in the flow rate set by the flow rate setting means.

Further, in this abnormal fluid flow prevention control device, a bypass circuit is provided in the flow path system, and a switching valve is arranged for causing a part of the fluid to flow into the bypass circuit according to a command from the controller.

Furthermore, in this abnormal fluid flow prevention control device, the abnormal flow detection circuit and the controller are built into a valve driving device.

[Effect]

Since the abnormal fluid flow prevention control device according to the present invention is configured as described above, it operates as follows. In other words, the vibrations that the acceleration sensor detects as vibrations occurring in the flow path system of piping, etc. include a wide variety of vibrations, such as vibrations caused by abnormal flow such as cavitation, as well as vibrations applied from the outside by machinery, etc. be. All of the piping vibration signals measured by the acceleration sensor are input to the abnormal flow detection circuit, but the abnormal flow detection circuit can only pass abnormal signals in a specific frequency band.

These signals are further input to the controller, and the controller sends a valve drive signal that commands the valve opening/closing amount to a valve drive device such as an electric actuator for driving the valve. Adjust the opening of the valve installed in the pipe. By adjusting the opening degree of the valve, the flow rate flowing through the flow path system can be adjusted, and abnormal flow such as cavitation can be prevented.

Furthermore, since the cumulative time of occurrence of abnormal flow and the cumulative number of vibrations can be displayed on the display, maintenance and inspection of the flow path system piping, etc. can be performed at an optimal time.

〔Example〕

Hereinafter, one embodiment of the abnormal fluid flow prevention control device according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of the abnormal fluid flow prevention control device according to the present invention, and FIG. 2 is an explanatory diagram showing details of the valve driving device of FIG. 1.

The piping 1 of the flow path system includes a valve 2, a pressure sensor 3 disposed upstream of the valve 2, a pressure sensor 4 disposed downstream of the valve 2, a flow rate sensor 5, and an acceleration sensor 6.
, and a pressurizing pump 7 placed upstream of the piping 1. The valve 2 disposed in the piping 1 of this flow path system is driven to open and close by a valve driving bag f20 such as a valve driving electric actuator with a built-in electronic control device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 62-292978.

Pressure sensor 3.4 detects the pressure before and after valve 2,
The detected data is input to the arithmetic control section 15 built into the valve drive device 20. The flow rate sensor 5 detects the flow rate downstream of the valve 2, and inputs the detected measurement data to the arithmetic control section 15 of the valve driving device 20 as well as to the central controller 30.

An acceleration sensor 6 attached to the flow path system, particularly the outer wall of the pipe 1 or the outer wall of the valve 2 or valve drive device 20, detects the acceleration of vibration occurring in the pipe l, and the detected vibration data is abnormal. 5 are input to the flow detection circuit 13. This abnormal flow detection circuit 13 outputs an abnormal flow detection signal to the controller 30 when an abnormality is detected in the flow of fluid. The controller 30 receives the signal from the abnormal flow detection circuit 13 and issues a signal instructing the valve driving device 20 to open/close the valve 2 . controller 3
Specifically, the signal that commands the opening/closing amount of the valve 2 that the valve drive device 20 issues is, for example, a flow rate signal.

Further, the pressurizing pump 7 is capable of adjusting the supply pressure of the fluid flowing through the piping 1 in response to a command from the controller 30.

Next, the configuration of the valve driving device 20 will be explained with reference to FIG. A serial data signal from the controller 30, which is a central control device, is input to the serial interface section 14, which is an external data receiving section, and predetermined data processing is performed at the arithmetic control section 15. The output signal from the calculation control section 15 is transmitted to the solid state relay 1.
In response to the signal, the reversible motor 17 performs the required rotation, and the opening degree of the valve 2 installed in the pipe 1 can be controlled via the reducer 18. The valve opening degree, that is, the amount of movement of the valve 2 due to the opening/closing drive, is fed back to the calculation control section 15 via a potentiometer 19 provided in the reducer 18 . Flow rate sensor 5 provided in piping 1
The signal is fed back to the calculation control unit 15 via the A/D converter.

FIG. 3 is a block diagram of the serial interface section 14 and calculation control section 15 in FIG. 2.

Signals from the controller 30 are input to the serial I10 port 21. Additionally, various information near the valve drive device 20 is input to the A/D converter 22 . That is,
In the example shown in FIG. 2, the signal from the flow rate sensor 5 is input to the A/D converter 22. Each of these signals is stored in the RAM 23, and the CPU 25 performs necessary calculations in accordance with a predetermined program in the ROM 24. It is output to relay 16.

Next, the operation of this valve drive device 20 will be explained. Now, when the controller 30 issues a command for the flow rate Ql/sec, the command is input to the serial I10 port 21 as serial signal data. The A/D converter 22 receives a current flow rate Q, /sec %, which is a pressure signal from a pressure sensor 3.4 provided before and after the valve 2.
Information such as next pressure P, , secondary pressure P7, etc. is input. R
For example, the OM24 has a chart based on the pressure P, flow rate Q, and valve opening degree K, and the current flow rate Qz
, primary pressure P, , secondary pressure P2 and the values on the ROM 24, the CPU 25 performs a predetermined calculation, and the data in the RAM 23 is rewritten based on the results.
A signal is output from the I10 boat 21, and the reversible motor 17,
The opening degree of the valve 2 is adjusted via the reducer 18. The opening degree of the valve 2 is fed back every moment to the arithmetic control section 15 via a potentiometer 19. When the flow rate signal Q,/sec from the flow rate sensor 5 reaches a preset value Q,/sec, the operation of the reversible motor 17 is stopped, and a constant flow rate Ql/sec is maintained.

When a change occurs in the primary pressure P or the secondary pressure P2, the signal is not sent to the controller 30, but a predetermined calculation is performed by the CPU 25 on the valve driving bag W20 side, and the flow rate Q, /sec. A signal for controlling opening and closing of the pulp 2 is outputted so that fluctuations do not occur.

FIG. 4 shows a schematic diagram of the abnormal flow detection circuit 13 incorporated in the abnormal fluid flow prevention control device according to the present invention. The detection signal detected by the acceleration sensor 6 is amplified by an amplifier 8, and then passed through various filters 9A, 9B, 9G, 9D.
is input. Filters 9A, 9B, 9C, and 9D pass vibration data in four predetermined frequency bands, and input the vibration data to multiplexer 10. The multiplexer 10 is a circuit that has a function equivalent to a changeover switch that extracts only a necessary input signal from among a plurality of input signals. In this example, one signal is selected from four input signals and output to the A/D converter 12. Selection of signals is performed by a selector setting device 11.

9 That is, among the four filters 9A, 9B, 9C, and 9D,
The selector setter 11 is set so that only the signal from a predetermined filter through which vibration data has passed is connected to the A/D converter 12 when cavitation occurs.

An example of the filters 9A, 9B, 9C, and 9D will be described with reference to FIG. In the graph of Figure 7,
The frequency f is plotted on the horizontal axis, and the output amplitude H is plotted on the vertical axis. The filter 9A, as shown in A of FIG.
This is a band rejection filter that rejects frequencies in the code a band. The filter 9B is a band-pass filter that passes the frequency of the band shown in FIG. 7A. The filter 9C is a high-pass filter that passes frequencies in a band higher than frequency C and blocks frequencies in a band lower than frequency C, as shown in C in FIG. Further, as shown in D in FIG. 7, the filter 9D is a low-pass filter that blocks frequencies higher than the frequency d and passes frequencies lower than the frequency d. .

Therefore, when cavitation occurs in the flow path system,
Only vibration data of a specific frequency is sent to the A/D converter 12.
and further output to the controller 30 as an abnormal flow detection signal. Note that, of course, instead of configuring the abnormal flow detection circuit 13 with the filters 9A, 9B, 9C, 9D and the multiplexer 1O1 A/D converter I2 as described above, a Fourier transform IC may be used.

Next, an example of the controller 30 in this abnormal fluid flow prevention control device will be described with reference to the block diagram of FIG. 5.

In FIG. 5, the amplitude detection means 35 detects the amplitude of the abnormal flow detection signal inputted from the abnormal flow detection circuit 13, which indicates the strength of cavitation. The vibration number counting means 34 counts the cumulative value from the past regarding the number of vibrations when cavitation occurs. The timer 32 measures the duration of cavitation occurrence,
When the abnormal flow detection signal is no longer input, the duration is transmitted to the cumulative time calculation means 31. The cumulative time calculation means 31 calculates the cumulative value of the time when cavitation occurred from the past. The recorder 29 also stores the cumulative time sent from the cumulative time calculating means 31 and the cumulative number of vibrations sent from the vibration frequency counting means 34, and stores these cumulative times and the cumulative number of vibrations. The cumulative time and cumulative number of vibrations can be displayed on the display 28 if necessary. By monitoring this display 28, maintenance and inspection work can be performed on the flow path system at an optimal time. Furthermore, the flow rate setting means 3
Reference numeral 7 indicates a command for the flow rate Q, /sec as the valve opening/closing amount to the valve driving electric actuator, that is, the valve driving device 20, and the flow rate Q, /sec is equal to the flow rate Q2/sec measured by the flow rate sensor 5. sec
is input through A/D exchange, and the flow rate Qz/sec is calculated by multiplying it by an appropriate coefficient. In this case, the amplitude comparing means 36 compares the amplitude detected a predetermined time ago by the amplitude detecting means 35 and the current amplitude, and sets the flow rate Ql/see so that the amplitude becomes smaller.

Next, the abnormal fluid flow prevention control device according to the present invention includes:
The operation of suppressing cavitation by the abnormal fluid flow prevention control device configured as described above will be explained with reference to the process flow diagram shown in FIG. 6.

A signal detected by the acceleration sensor 6 from the pipe 1 is input to the abnormal flow detection circuit 13, amplified by the amplifier 8, and then sent to the filters 9A, 9B, and 9C.

9D and is input to multiplexer IO.

Here, since the multiplexer 10 cannot output only the vibration data of the specific frequency band set by the selector setting device 11 to the A/D converter 12 side, normally no signal is output to the A/D converter 12. However, when cavitation occurs, the multiplexer 10 outputs the signal to the A/D converter 12, and the abnormal flow detection signal is input to the controller 30 (step 40). In the controller 30, the amplitude detection means 35 detects the amplitude A1. (Step 41), the flow rate Q47sec measured by the flow rate sensor 53 (Step 4
Based on 2), the flow rate setting means 37 calculates the flow rate Ql/seC (step 43) and issues a command to the valve driving device 20 (step 44).

When the controller 30 issues a command for the flow rate QI/sec, the valve drive device 20 operates as described above to adjust the opening degree of the valve 2 to achieve the set flow rate QI/sec.
c is obtained (step 45). Then, the amplitude comparison means 36
In step 46), the amplitude A1 detected last time and the amplitude A detected this time are compared and determined, and the result is output to the flow rate setting means 37. If the amplitude becomes small, the flow rate setting means 37 increases the flow rate a little more (step 47).
On the other hand, if the amplitude is large, the flow rate is decreased to set the flow rate (step 48), and a flow rate command is sent to the valve driving device 20 again (step 44). The controller 30 repeats the above control steps until cavitation is suppressed, thereby preventing cavitation from occurring in the flow path system.

4 Or, if the cavitation phenomenon is not easily suppressed, that is, if the elapsed time measured by the timer 32 exceeds a predetermined time, a signal is issued from the timer 32 to the pressurization pump control device 33, and the pressurization is stopped. Pump control device 33
The supply pressure may be adjusted by.

Alternatively, in order to ensure a constant amount of work, the flow rate setting means 37 of the controller 30 may be adjusted as cavitation occurs.
If the flow rate is increased by X%, the pressurizing pump control device 33 may correspondingly decrease the supply pressure by X%, and conversely, if the flow rate is decreased, the pressure may be increased.

Further, it is also possible to provide a bypass circuit piping in the piping 1 and, if necessary, provide another switching valve so that a part of the fluid flows through the bypass piping.

In the above embodiment, the case where cavitation occurs has been described, but the present invention is not limited to cavitation and can be applied to any abnormal flow.

Further, in the above embodiment, a case has been described in which the controller 30 and the abnormal flow detection circuit 13 are provided outside the valve drive device F20, but one or both of these may be built in the valve drive device 20.

In addition, in the above embodiment, the case where only one valve is to be controlled was explained, but in systems such as water purification plants, wastewater treatment systems, temperature control systems, continuous carburizing furnace control systems, etc., the flow can be controlled. It goes without saying that the present invention is applicable to the case where a plurality of valves are controlled. In that case, the selector setter 11 of the multiplexer 10 is set for each location where this control device is set. Further, it is preferable that the function of the controller 30 is provided in one central control device.

〔Effect of the invention〕

Since the abnormal fluid flow prevention control device according to the present invention is configured as described above, it has the following specific effects.

That is, this abnormal fluid flow prevention control device can instantly detect the occurrence of cavitation, and as a result, automatically adjust the opening degree of the valve and the supply pressure, thereby preventing cavitation.

Therefore, even when the abnormal flow suppression control device of the present invention is applied to liquid pumping equipment where a large number of valves are used, such as in a wastewater treatment plant, depending on the abnormal flow near the valve setting point, This method has the advantage that it can be applied simply by setting the frequency band that passes through the abnormal flow detection circuit.

In addition, it is possible to display the strength of cavitation and the cumulative amount of time it has occurred, so it is possible to not only know the optimal periodic inspection timing, but also to recognize which parts of the entire plant are suffering from the most damage. .

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an embodiment of the abnormal fluid flow prevention control device according to the present invention, and FIG. 2 shows an example of a valve driving device that can be incorporated into the abnormal fluid flow prevention control device of FIG. 1. FIG. 3 is a block diagram showing the concept of the serial 2 full interface section and calculation control section in the valve driving device of FIG. 2, and FIG. 4 is an abnormal flow detection of the abnormal fluid flow prevention control device according to the present invention. A schematic explanatory diagram showing the circuit,
FIG. 5 is a block diagram illustrating an example of a controller that can be incorporated into the abnormal fluid flow prevention control device shown in FIG. 1, and FIG. 6 shows an example of the operation of the abnormal fluid flow prevention control device shown in FIG. The processing flow diagram and FIG. 7 are explanatory diagrams illustrating an example of a filter that can be connected to the abnormal fluid flow prevention control device of FIG. 1. 1・-11111 piping, 2・・・・−・−valve, 3.
4.--1--Pressure sensor, 5-----Flow rate sensor, 6---Acceleration sensor, 7--
--1---Pressure bomb, 8~----1 amplifier, 9A
9B, 9C, 9D・---- Filter, 10・---
---Multiplexer, 11--Selector setting device, 12---A/D converter, 13---Abnormal flow detection circuit, 15---Arithmetic controller section, 20
-・-Valve drive device, 28・-----1 indicator, 2
9--Recorder, 30--Controller, 31
...-cumulative time calculation means, 32-----one timer,
33... Pressure pump control device, 38 4-- Vibration number counting means, 35-... Amplitude detection means,
36-.--Amplitude comparison means, 37-.-Flow rate setting means.

Claims (9)

[Claims] (1) A valve provided in a fluid flow path system, a valve driving device that adjusts the opening degree of the valve, an acceleration sensor provided in the fluid flow path system, and abnormal flow occurs in response to a detection signal from the acceleration sensor. an abnormal flow detection circuit that outputs a signal in a frequency band of , and a controller that outputs a valve drive signal to the valve drive device in response to the output signal from the abnormal flow detection circuit to control the opening degree of the valve. Abnormal fluid flow prevention control device. (2) The abnormal flow detection circuit includes an amplifier that amplifies the signal from the acceleration sensor, a filter that passes only a signal of a specific frequency among the signals from the amplifier, and a multiplexer that passes only the signal when an abnormal flow occurs. The abnormal fluid flow prevention control device according to claim 1, further comprising an A/D converter that converts the signal from the multiplexer into an A/D converter. (3) The controller includes amplitude detection means for detecting the amplitude of the abnormal flow detection signal inputted from the abnormal flow detection circuit, amplitude comparison means for comparing the amplitude before a predetermined time with the current amplitude, and 2. The abnormal fluid flow prevention control device according to claim 1, further comprising a flow rate setting means for setting a flow rate to be commanded to the valve driving device based on the flow rate. (4) The abnormal fluid flow prevention control device according to claim 1, wherein the controller has a display device that displays the cumulative time of abnormal flow occurrence and the cumulative number of vibrations. (5) The display device includes amplitude detection means for detecting the amplitude of the abnormal flow detection signal inputted from the abnormal flow detection circuit, and amplitude recovery counting means for counting the accumulated value from the past regarding the number of amplitudes when abnormal flow occurs. , a timer that measures the duration when an abnormal flow occurs, a cumulative time calculation means that calculates the cumulative time from the past by adding the duration transmitted from the timer when the abnormal flow detection signal is no longer input; It consists of a recorder for storing the cumulative time sent from the time calculation means and the cumulative number of vibrations sent from the vibration frequency counting means, and a display for displaying the cumulative time and the cumulative number of vibrations as necessary. The abnormal fluid flow prevention control device according to claim 4. (6) The abnormal fluid flow according to claim 1, wherein the controller includes a pressurizing pump control device that controls the supply pressure of the pressurizing pump in response to a signal that cannot prevent the abnormal flow even after a predetermined period of time has elapsed. Prevention control device. (7) The abnormal fluid flow prevention control device according to claim 1, wherein the controller includes a pressurizing pump control device for ensuring a constant amount of work in response to increases and decreases in the flow rate set by the flow rate setting means. (8) The abnormal fluid flow prevention control device according to claim 1, further comprising a bypass circuit provided in the flow path system, and a switching valve for causing a part of the fluid to flow into the bypass circuit according to a command from the controller. (9) The abnormal fluid flow prevention control device according to claim 1, wherein the abnormal flow detection circuit and the controller are built into a valve driving device.