JPH0255840B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to devices and devices controlled or regulated by fluids, such as steam turbines, gas turbines,
Physical quantities important for operation in multichannel and majority switch matrices, generally X-out-of-Y-systems, e.g. 2-out-of-3-
This invention relates to a safety circuit for monitoring using a system.

In order to monitor important physical quantities in devices and equipment that are exposed to hazards or are hazardous to the living environment, a large number of homogeneous parallel channels are provided, which are connected to each other by a switch matrix. However, at that time, if a certain number of channels among the installed channels simultaneously indicate a failure, this indication will be transmitted as a failure indication determined by majority logic, and an alarm will be issued or an immediate It is designed to shut off the device. Such a method is generally called an X-out-of-Y-system, and a 2-out-of-3-system is usually used. In this case, a fault alarm is issued or a protective device is activated when at least two of the three channels provided are connected at the same time.
This is only when you specify two obstacles.

Among such devices, those for monitoring nuclear power plants are disclosed in German Federal Republic Patent No. 1764955;
and from German Patent Application No. 2235937.

However, these monitoring devices themselves are subject to malfunctions and failures. Therefore, for safety reasons, it is necessary to constantly monitor whether such a monitoring device itself is operating without any defects.

A two-out-of-three circuit using electrical relays is known from German Patent Application No. 1067508. The contacts of these relays are interconnected by two circuits, one of which is the original control circuit, and the other is a circuit that monitors whether the relay itself is operating without any defects. It emits a signal when it malfunctions.

In the article "Auswärgesteem zur Erhoeung Deasitzhierheit von Signalen" in the specialized journal "Regerungstechnique", Vol. 3, 1958, 93-96, the measured values of all channels are periodically or , a circuit is described that constantly compares them with each other and thereby quickly detects and reports faults in the measurement channel.

All known monitoring devices of this type operate exclusively with electrical quantities. Therefore, for instruments and devices controlled or regulated by fluids, such as fluid intake valves in steam and gas turbines, special logical coupling elements are required to exchange fluidic data into electrical ones. It is necessary to provide

The object of the invention is to avoid such expensive coupling elements, which are also subject to the risk of failure, and to reduce costs.

This problem is solved by configuring the switch matrix in a combined electrical and hydraulic manner.

Hereinafter, the operation and details of the apparatus of the present invention will be explained in detail using the drawings for a 3-out-of-2 system.

FIG. 1 is a circuit diagram of the principle of the device of the present invention expressed using element symbols known in electronic engineering. The upper part corresponds to the part related to fluid pressure, and the three measurement channels are each equipped with an OR gate. The output side of these OR gates is one
Connected to AND gate. If a voltage is applied to the channels, the pressure at the pressure switches 4, 5, 6 and the port 19 (see FIGS. 2 to 5) is then high and therefore in a protective state. Conversely, when the voltage of channels , , becomes zero, pressure switches 4, 5, 6 and port 1
The pressure at 9 decreases, thereby initiating a protective effect. On the other hand, the electrical (or electronic) related part consists of three exclusive OR gates connected to the three channels, , and the output sides of the OR and AND gates, and these exclusive OR gates are Selectively display faults. At this time, the application of voltage to the failure report indicators 16, 17, and 18 means that there is a failure in each channel.

In the diagrams of FIGS. 2 to 5, in the present invention,
Three ORs assigned to three measurement channels
Various operating states of the monitoring circuit are shown using a fluidic device to implement the functions of a gate and a common AND gate.

In the state shown in Figure 2, there are three channels,
，Everything is in normal and unimpeded readiness. That is, the electromagnetic coils 1, 2, 3 of the three electromagnetic valves
All are suctioning, three pistons 7, 8,
The pressure of the pressure fluid above 9 is relieved. All pistons are blocked from flowing into port 20. The pressure in fluid path 11 corresponds to the supply pressure at supply port 10. The pressure fluid thus maintains the components connected to the pressure transmission port 19 in normal operating condition. For example, leave the turbine's quick-close valve open. three solenoid valves 1,
At the same time as the pressure is released by switches 2 and 3, the pressure switch 4,
5 and 6 are acted upon, and the changeover switches 4', 5',
6' is operated and at the same time the transfer switches 13, 14, 15, also operated by the pressure switch 12, switch all three lines, so that all three channel fault indicators are in the no-current state.

Conversely, Figure 3 shows that all three channels,
, indicates the case of a fault condition indicated by .
In this case, all three floating pistons 7, 8, 9 are in the upper end position, and the oil amount is restricted by the throttle 11', so that no pressure is applied in the fluid path 11, and the pistons 7, 8, 9 The upper chamber is closed to the outflow port 20 because the solenoid valves 1, 2, and 3 are not energized.
Since the pressure fluid enters the pressure fluid device from the supply port 10, the pressure fluid flows out from the outlet port 20. Since the switch 12 is also restored when the three pressure switches 4, 5, and 6 are restored, the channel fault notification displays 16, 17, and 18 do not display any fault.

Another situation is shown in FIG. channel, is in the protection ready state, solenoid valves 1 and 2
is attracting. A fault has occurred in the channel and the solenoid valve 3 remains de-energized. Three original active pressure surfaces and two diaphragm
Due to the special configuration of the pistons 7, 8, 9 with seals, the piston 9 receives overpressure from above via the fluid path from the adjacent solenoid valve 2 and the outflow port 2
Close the fluid path leading to 0. Pressure is applied to port 19 to maintain the components connected thereto in normal operating condition. However, on the other hand, pressure switch 6 has
Since the electromagnetic valve 3 does not respond, no pressure is applied, so the changeover switch 6' is not switched, and voltage is applied to the fault notification display 16 for the channel.

In the state shown in Figure 5, the two channels are
Normal, indicating a device operational failure; one channel is not indicating a failure due to its own failure. The solenoid valve of the faulty channel is suctioned, so that the pistons 7, 8 receive overpressure from above and prevent the outflow. However, since the piston 9 is still raised, the pressurized fluid can flow out from the outlet port 20, and the normal operating pressure in the fluid path 11 is no longer applied to the port 1.
The member connected to 9 reacts. On the other hand,
The pressure switch 4 receives pressure, and the changeover switch 4'
Switch. This applies voltage to the channel's fault notification indicator.

As is clear from the above, 2-out-of-3-
The safety circuit according to the invention using the system always operates reliably and ensures that faulty channels are selectively indicated in any operating state.

For safety reasons, the connection terminals for the power supply in the embodiment described above are selected in such a way that a protective action is taken whenever the power supply is interrupted.

[Brief explanation of the drawing]

FIG. 1 is a principle circuit diagram showing the safety circuit of the present invention using electronic symbols. 2 to 5 are diagrams showing various operating states of the monitoring circuit of the present invention. ,,...Measurement channel, OR...OR gate, AND...AND gate, EX...Exclusive OR gate, S~S...Fault reporting channel for each measurement channel, 1, 2, 3...Magnetic coil ,
4, 5, 6, 12...pressure switch, 4', 5',
6'...Selector switch, 7, 8, 9...Piston,
10... Supply port, 11... Fluid path, 11'...
... Throttle valve, 13, 14, 15... Selector switch,
16, 17, 18... Trouble report display, 19...
Pressure transmission port, 20...Outflow port.

Claims (1)

[Scope of Claims] 1. Physical quantities important for the operation of devices and devices controlled or regulated by fluids can be controlled by multichannel, majority decision switch matrix,
In the safety circuit for monitoring using a Y-system, each monitoring channel, when implemented as a 2-out-of-3 system, is operated by a hydraulically actuated pressure switch 4, 5, 6, respectively. Electric switches 4', 5', 6', solenoid valves 1, 2, 3,
and floating diaphragm seal type pistons 7, 8, 9 are respectively assigned, and the pistons are connected to two channels (1+2, 2+
3, 3+1) in one direction, and in the other direction by the currently existing throttle valve 1.
A further pressure switch 12 is provided in the flow path 11 of the throttled fluid and is provided with a number of electrical contacts 13 corresponding to the number of channels of the pressure switch. ,1
4 and 15 are connected in series with each other in a crosswise manner with the electrical contacts 4', 5' and 6' of the pressure switches 4, 5 and 6. 2 Pressure switch 4 assigned to the channel,
A patent claim in which fault notification indicators 16, 17, 18 are connected to contacts 4', 5', 6' of output side pressure switch 12 and contacts 13, 14, 15 of pressure switch 12 on the output side for each channel. The safety circuit described in item 1. 3. The safety circuit according to claim 1 or 2, wherein all fluidic element materials of all channels are unified into one unit. 4 Pistons 7, 8, 9 have two different diameters and 2
two fixed diaphragm seals, and pressurization is applied to both diaphragm seals by means of the other solenoid valves 1, 2, 3, each connected in a cyclical sequence.
A safety circuit according to any one of claims 1 to 3, which is implemented in the space between the seals.