JPS5987398A - Valve divergence control device for air operation type regulating valve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a valve opening degree control device for an air-operated control valve that can be applied to a PWR grand main water supply control valve and a general control valve.

In the conventional valve opening control device for air-operated control valves,
It was a series system that supplied a pressurized air signal to the diaphragm by passing the 11° command signal of the air control valve through an electro-pneumatic converter and a positioner. Therefore, there was a drawback that the function of the valve could be lost due to a failure of the positioner or electro-pneumatic converter.The present invention was proposed in view of the above circumstances, and the pneumatic control device is made into a duplex system and has a switching system. An object of the present invention is to provide a valve opening control device for an air-operated control valve that can improve the reliability of the valve opening control device by adding an air pressure control system that eliminates fluctuations in the valve during operation.

The valve opening control device for an air-operated control valve according to the present invention includes an electro-pneumatic converter (a converter that converts an electric signal into a pneumatic signal), a positioner, and a booster relay, which are arranged in parallel with each other. an emergency pneumatic control device;
An abnormality diagnostic device that switches from normal use to emergency use, and an air pressure adjustment device that is provided between the outlet of the normal booster relay and the inlet of the emergency booster relay and is operated by the detection output of the abnormality diagnostic device. It is characterized by:

An embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing the relationship between the opening command signal and the air pressure of the electro-pneumatic converter in the embodiment shown in FIG. 1. , FIG. 3 is a characteristic diagram showing the relationship between the opening command signal and the valve lift signal in the embodiment shown in FIG. 1.

FIG. 4 is a characteristic diagram showing the relationship between the opening command signal and the valve lift signal when the allowable change range is set in the embodiment shown in FIG.

In FIG. 1, 11 is a control valve, 12 is a diaphragm, 1
3 is a switching valve, 14 is an opening command signal, 15 is a switching device, 16
is the opening signal, 17 is the abnormality diagnostic device, No. 8 is the switching signal, 20
is a regular pneumatic control device, 20a is a regular electro-pneumatic converter, 20
b is a regular positioner, 20C is a regular booster relay, 3
0 is an emergency pneumatic control device, 30a is an emergency electro-pneumatic converter 1. ? Ob is an emergency booster, 30c is an emergency booster relay, 40 is an air pressure regulator, 40a is an air pressure regulator booster relay, 40b is an air reservoir, and 40c is an air pressure regulator valve.

In FIG. 1, a control valve 11 for regulating the flow rate of a desired fluid can be opened by a predetermined opening degree by a diaphragm 12 provided in a diaphragm chamber. Pressurized air corresponding to the opening command signal 14 of the control valve 1 is supplied to the diaphragm chamber from the regular air pressure control device 20 via the switching valve 13. The opening command signal 14 is the switching device 1
5 to the service air pressure control device 20. The opening signal 16 supplied from the regular air pressure control device 20 to the control valve 11 is also supplied to the abnormality diagnostic device 17. The abnormality diagnostic device 17 uses this opening signal 1.
6 and the opening command signal 14, a predetermined switching signal 18 is supplied to the switching valve 13, the switching device 5, and the air pressure regulating valve 40c. Here, the regular air pressure control device 20
has a regular electro-pneumatic converter 20h to which a predetermined opening command signal 14 from the switch 5 is supplied. Is the regular electro-pneumatic converter 20a used regularly? One pressure air corresponding to the opening command signal 14 is supplied from the switching valve 13 to the diaphragm 12 via the positioner 20b and the regular booster relay 20c. ! , the switch 15 supplies an output according to the opening command signal 14 to the emergency electro-pneumatic converter 30a in the emergency pneumatic pressure control device 30 that constitutes the control mechanism of the standby system.

The emergency electro-pneumatic converter 30a receives the opening command signal 14 via the emergency positioner 30b and the emergency booster relay 30c.
Pressurized air corresponding to the changeover valve 13 is supplied to the diaphragm 12. Note that the opening signal 16 is the normal opening positioner 20b and the emergency I positioner, ? One supply is supplied to Ob.

Further, the pressurized air supplied from the regular air pressure control device 20 to the diaphragm 12 via the switching valve 13 is also supplied to the air pressure adjustment device 40. The air pressure adjustment device 40 supplies this pressurized air to the emergency booster relay 30c via the air pressure adjustment boot 5-star relay 40a.
supply to. The outlet pressure of the emergency booster relay 30c would be atmospheric pressure without the air pressure regulator 40, but by providing the air pressure regulator 40, it is made to be the same pressure as the outlet pressure of the regular booster relay 20c. .

The operation of the embodiment of the present invention shown in FIG. 1 will be explained based on FIGS. 1 to 4. The valve opening control device for the air-operated control valve shown in FIG. 1, constructed as described above, controls the opening of the control valve 1 in the following manner. First, in normal opening adjustment, the opening command signal 14 supplied from the outside is converted into a pneumatic pressure signal by the regular electro-pneumatic converter 20a. In this case, the relationship between the opening command signal No. 4 and the air pressure signal is a linear function as shown in FIG. Therefore, the normal position, Na 20b, is determined by the following formula (1) when the lift of the control valve 11 is L and the air pressure signal is P.
) to your satisfaction.

L = a P 10b ・・・・・・・・・・・・
(1) Here, a and b are constants, and if L)aP + , the outlet air pressure of the positioner 20b for 6- is lowered. The commonly used North Talyrelay 20c is a width device, and the diaphragm 1
2 to match the outlet pressure of the regular positioner 20b. If the pressure of the diaphragm 12 is higher than the outlet pressure of the service positioner 20b, the diaphragm 12
The air inside is exhausted to the atmosphere and the pressure of the diaphragm 12 is lowered. In addition, the pressure of the diaphragm 12 is
If the pressure is lower than the outlet pressure of b, air is pumped into the diaphragm 12.

If the pressure in the diaphragm 12 becomes high, the valve lift will rise, and if it becomes low, it will fall. In this way, the commonly used positioner 20
A linear function relationship as shown in FIG. 3 is established between the valve lift and the opening command signal 140. The abnormality diagnostic device 17 detects whether or not this valve lift and the opening command signal No. 4 satisfy a predetermined linear function shown in FIG. When the opening command signal 14 and the valve lift signal deviate from this permissible change range, it is determined that the control valve 1 is abnormal.

When it is necessary to improve the reliability of abnormality determination of the control valve 1, the gross state quantity is used as the material for determination.

If the abnormality diagnostic device 17 detects a control abnormality, the switching valve 1
3 and the switch 15 to switch the control of the regulating valve 1 to the emergency air pressure control device 30. Emergency electro-pneumatic converter 30a and emergency positioner 30b when switched to emergency use
The operation of the emergency booster relay 30c is the same as that of each of the above-mentioned regular devices. The switching valve J3 normally transmits the output of the regular booster relay 20c to the diaphragm 12, and transmits the output of the emergency booster relay 30c to the diaphragm 12 when an abnormality in the valve is detected and is switched to emergency use. The switching device 15 still transmits the opening command signal 14 to the regular electro-pneumatic converter 20a under normal conditions, and when a valve abnormality is detected and the switch is switched to emergency use,
The opening command signal 14 is transmitted to the emergency electro-pneumatic converter 30&.

The air pressure regulating device 40, which consists of an air pressure regulating booster relay 40a, an air reservoir 40b, and an air pressure regulating valve 40c, is configured to make the outlet air pressure of the regular booster relay 20c and the outlet air pressure of the emergency booster relay 30c the same pressure. The mechanism is shown next.

The air pressure regulating booster relay 40a matches the outlet pressure of the regular booster relay 20c with the pressure of the air reservoir 40b.

If the pressure in the air reservoir 40b is higher than the outlet pressure of the regular booster relay 20c, the pressure in the air reservoir 40b is lowered.

Furthermore, if the pressure in the air reservoir 40b is lower than the outlet pressure of the regular booster relay 20c, air is sent into the air reservoir 40b. The pressurized air in the trench air reservoir 40b is supplied to the inlet of the emergency booster relay 30e, and by passing through the emergency booster relay 30c, the outlet pressure of the emergency booster relay 30C becomes the same pressure. Therefore, the emergency booster relay 30
The outlet pressure of c is normally maintained at the same pressure as the outlet pressure of the regular booster relay 2θC through the air pressure regulator 40.

When the abnormality diagnostic device 17 detects a control abnormality and switches the control valve control to the emergency air pressure control device 30, the outlet pressure of the regular booster relay 20c decreases rapidly, but the air reservoir 40
If the air capacity of b is set large, the inlet pressure of the emergency booster relay 30c will not drop. Therefore, the outlet pressure of the emergency booster relay 30c does not decrease, so the switching valve 1
There is no difference in pressure from the diaphragm 12 when switching 3.
Therefore, there is no pressure fluctuation in the diaphragm 12. Also, after switching to the emergency pneumatic control device 30, the emergency positioner 3
In order to prevent the air pressure signal supplied from θb to the emergency booster relay 30c from flowing out to the air reservoir 40b, the air pressure regulating valve 40c is completely closed immediately after switching.

Since the present invention is configured as described above, the pneumatic pressure control device is provided with an emergency pneumatic control device in addition to the regular pneumatic control device, so that when the normal pneumatic control device breaks down, it is switched to the emergency pneumatic pressure control device.
By adopting a weighted system, the reliability of the valve opening control device for the air control valve is improved. Moreover, by adding the above air pressure regulator, the emergency booster relay outlet pressure is maintained at the same pressure as the normal booster relay outlet pressure, so switching from the normal air pressure control device to the emergency air pressure control device is easy. At this time, there is no difference between the pressure of the diaphragm 12 and the valve does not fluctuate, which is an excellent effect.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a characteristic diagram showing the relationship between the opening command signal and the air pressure of the electro-pneumatic converter in the embodiment shown in FIG. 1. , Fig. 3 is a characteristic diagram showing the relationship between the opening command signal and the valve lift signal in the embodiment shown in Fig. 1, and Fig. 4 shows the setting of the allowable change range in the embodiment shown in Fig. 1. FIG. 3 is a characteristic diagram showing the relationship between an opening command signal and a valve lift signal. 1...Control valve, 12...Diaphragm, 13...
- Switching valve, 14... Opening command signal, 15... Switching device, 16... Opening signal, 17... Abnormality diagnostic device, 18.
...Switching signal, 20...Common air pressure control device, 20h
...Common use electro-pneumatic converter, 20b...Common use 2 positioner,
20c... Regular use booster relay, 3o... Emergency pneumatic control device, 3oa... Emergency electro-pneumatic converter, 30b
... Emergency positioner, 30c... Emergency booster relay, 4o... Air pressure adjustment device, 40a... Air pressure adjustment booster relay, 40b... Air reservoir, 40c...
...Air pressure control valve.

Claims (1)

[Claims] Regular and emergency pneumatic control devices, such as electro-pneumatic converters (converters that convert electrical signals to pneumatic signals), positioners and booster relays, are arranged in parallel with each other, and switch from regular to emergency. and an air pressure adjustment device that is provided between the outlet of the regular booster relay and the inlet of the emergency booster relay and is operated by the detection output of the abnormality diagnostic device. Valve opening control device for type control valves.