JPH0365718B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a device for monitoring the operating status of equipment such as various valves installed in a reactor containment vessel of a nuclear power generation facility. [Technical Background of the Invention] Generally, a large number of devices, such as various valves, are provided within the reactor containment vessel of a nuclear power generation facility.
The operating states of these valves, such as their open and closed states, are configured to be remotely monitored from outside the reactor containment vessel by a monitoring device. Conventionally, this monitoring device was constructed as shown in FIG. That is, numerals 1 in the figure are devices to be monitored, such as valves, and each of these valves 1 is provided with a limit switch 2 that opens and closes in response to the opening and closing of the valve 1. Each of these limit switches 2... has a cable 3...
is connected. And these cables 3...
are led out to the outside by penetrating the wall 5 of the reactor containment vessel via cable penetrations 4, respectively. A power source 6 and a display 7 are connected to these cables 3, respectively. Therefore, valve 1... is activated and becomes open,
When the limit switch 2... is closed, the display 7...
is activated, thereby monitoring whether the valves 1 are open or closed. [Problems with Background Art] In conventional systems, when a cable is passed through a wall of a reactor containment vessel, a cable penetration must be provided for each cable. For this reason,
When the number of devices such as valves is large, the number of cables is also large, and a large number of cable penetrations must be provided, resulting in a complicated structure. [Object of the Invention] The present invention provides an operating state monitoring device for equipment that can simplify the structure by reducing the number of cables penetrating the walls of the reactor containment vessel and by reducing the number of cable penetrations. It's about getting. [Summary of the Invention] The present invention provides a penetration cable provided to penetrate a wall in an air-tight or liquid-tight manner, and a cable branched from the penetration cable and provided corresponding to each device whose operating status is to be monitored. A plurality of branch cables each consisting of two parallel wires with different lengths, and an impedance between the wires at the tips of these branch cables provided at the ends of these branch cables in response to the operating state of the above-mentioned equipment. and a switch that switches between a state larger and a state smaller than the impedance of the penetration cable, a pulse oscillator that applies a pulse signal to the penetration cable, and a polarity and reception of the pulse signal reflected at the tip of the branch cable. The apparatus is equipped with a detection circuit that detects the operating state of the device whose operating state is to be monitored based on time. Therefore, since the length of each branch cable is different, the reception time of the reflected signal is different for each branch cable, that is, for each device, so it is possible to determine which device the reflected signal corresponds to from the reception time.
Furthermore, since the polarity of the reflected signal changes depending on the impedance at the tip of the branch cable, the operating state of the device can be determined from the polarity of the reflected signal. and,
Since the branch cable branches from the penetration cable, even if there are many devices, only one penetration cable is required, and the number of cable penetrations is also reduced, which simplifies the structure. be. [Embodiments of the Invention] Embodiments of the present invention will be described below with reference to FIGS. 2 to 5. A first embodiment is shown in FIGS. 2 and 3. 101a, 101b, 101c in the figure
...101n indicates a device such as a valve. And these valves 101a, 101b, 101c...101n
is installed inside the reactor containment vessel. In addition, 1
02 is the wall of this reactor containment vessel. Also, 1
03 is a penetration part cable. As shown in FIG. 3, this penetrating portion cable 103 is made of two parallel wires, and penetrates the above-mentioned wall 102 by a cable penetration 104. Then, branch cables 105a, 105 are provided corresponding to the above-mentioned valves 101a, 101b, 101c...101n, respectively.
b, 105c...105n are provided. These branch cables 105a, 105b, 105c...
105n has two parallel wires, and the branch 1
06 to the penetrating portion cable 103, and the tips thereof are wired to the vicinity of the corresponding valves 101a, 101b, 101c, . . . 101n, respectively. These branch cables 105a, 105b, 105c, . . . , 105n are formed to have different lengths. And these branch cables 105a, 10
Impedance switchers 107a, 107b, 107 are installed at the tips of 5b, 105c...105n, respectively.
c...107n is connected. These impedance switchers 107a, 107b, 107c...1
07n is branch cable 105a, 105b, 10
The impedance between the two wires at the tips of 5c...105n is determined by branching cables 105a, 105b, 105c...
105n and the impedance of the penetrating cable 103 or to a state smaller than the impedance of the penetrating cable 103. Note that in this first embodiment, these impedance switchers 107a, 107b, 107
A limit switch is used as c...107n. Therefore, these impedance switching devices 10
7a, 107b, 107c...107n, that is, if the limit switch is opened, the branch cable 10
The impedance between the two wires at the tips of the branch cables 105a, 105b, 105c...105n becomes almost infinite, and the branch cables 105a, 105b, 105c...105
n is larger than the impedance of the penetration cable 102, and when it is closed, the branch cable 105
The two wires at the tips of a, 105b, 105c...105n are short-circuited, and the impedance becomes almost zero,
Branch cables 105a, 105b, 105c...1
05n and the impedance of the penetration portion cable 103. These impedance switchers 107a, 107b,
107c...107n are valves 101a, 101b, 1
01c...101n, for example, the valves 101a, 101b, 101c...
When valve 101n is opened, it is opened, and valve 10
1a, 101b, 101c...101n is configured to be closed when the valves 1a, 101b, 101c...101n are closed. In addition, a pulse oscillator 10 is installed outside the reactor containment vessel.
8 is provided, and this pulse oscillator 108 is configured to apply a pulse signal with an extremely short pulse width to the penetration cable 103.
Further, this penetration cable 103 is connected to the detection circuit 10
Connected to 9. The detection circuit 109 includes a polarity determination circuit 110, a reception time measurement circuit 111, and an operating state determination circuit 112. The pulse signal transmitted from the pulse oscillator 108 passes through the penetration cable 103 and each branch cable 105a, 105b, 105c...105n, and passes through each branch cable 105a, 105b, 105n.
5c...105n, and the reflected signal is transmitted to each branch cable 105a, 105b, 105c.
... 105n and the penetration part cable 103 to the polarity determination circuit 110 and the reception time measurement circuit 11.
It is configured to be received at 1. and,
The polarity determination circuit 110 determines whether the polarity of the reflected signal is positive, that is, the same as the polarity of the pulse signal transmitted from the pulse transmitter 108, or the polarity of the reflected signal is negative, that is, the polarity is opposite to the polarity of the pulse signal transmitted. It is configured to determine whether or not. The determination result of this polarity determination circuit 110 is configured to be sent to an operating state determination circuit 112. In addition, the reception time measurement circuit 111
is configured to measure the time from transmission of the pulse signal to reception of the reflected signal. The measurement result of the reception time measuring circuit 111 is configured to be sent to the operating state determining circuit 112. The operating state determination circuit 112 includes a polarity determination circuit 110 and a reception time measurement circuit 111.
Each valve 101a, 101
b, 101c, . Further, 114 is a control circuit configured to receive command signals from the operation panel 115 and control the pulse oscillator 108, polarity determination circuit 110, reception time measurement circuit 111, operating state determination circuit 112, etc. ing. Next, the operation of this first embodiment will be explained. first,
A pulse signal is output from the pulse oscillator 108,
This pulse signal is transmitted from the penetration cable 103 to each branch cable 105a, 105b, 105c...10.
5n, and these branch cables 105a, 1
05b, 105c, . . . , 105n and is reflected by the detection circuit 109 . And each branch cable 105a, 105b, 105c...10
5n have different lengths, each branch cable 105a, 105b, 105 as shown in FIG.
c...Reflected signals from 105n S ₁ , S ₂ , S ₃ , S ₄ ...
The receiving times T ₁ , T ₂ , T ₃ , T _{4 ,} . . . , Tn from the transmission to the reception of the pulse signal S ₀ are different for Sn. Therefore, depending on the reception time, which branch cable 105a, 105b, 105c... the reflected signal is transmitted to?
105n, that is, which valve 101a,
101b, 101c...101n. Also, the level V of the signal reflected at the end of the cable is as follows: V = Z _L - Z _O / Z _O + Z _L , where Z ₀ is the impedance of the cable and Z L is the impedance between the lines at the end of the _cable. becomes. Therefore, the branch cables 105a, 105
Impedance switch 107a, 107b, 107c...107n at the tip of b, 105c...105n
is opened, and its impedance Z _L is branch cable 105a, 105b, 105c...105
n and the impedance of the penetration cable 103
For a value greater than Z ₀ , for example approximately infinity, V=1 and the polarity of the reflected signal will therefore be negative. In addition, impedance switching devices 107a, 107b,
107c...107n are closed, and its impedance Z _L is the branch cable 105a, 105
b, 105c...105n and penetration cable 1
If the impedance Z of 03 is smaller than Z ₀ , for example, approximately zero, then V=-1, and therefore the polarity of the reflected signal is negative. Therefore, depending on the polarity of the reflected signal, the impedance switchers 107a, 107b, 107c...107n are open or closed, that is, the valves 101a, 101b, 101c...101n are open or closed. can be determined.
The polarity and reception time of these reflected signals are determined by a polarity determination circuit 110 and a reception time measurement circuit 11.
1, and the operating state determination circuit 112 detects each valve 01a, 101b, 10 based on these.
The opening/closing operating states of 1c...101n are determined and displayed on the display 113. And this one is valve 101a, 101b, 1
01c...101n is large in number, branch cable 10
Even if there are a large number of cables 5a, 105b, 105c, . Further, the branching device 106 simply connects the cables in a branched manner, and in this embodiment, the impedance switching devices 107a, 107b, 10
Mechanical limit switches are used as 7c...107n. Therefore, there are no electronic components inside the reactor containment vessel, which is a radiation atmosphere, and the reliability is high. In addition, the penetration cable 103 and the branch cable 1
If there is an abnormality in 05a, 105b, 105c, . . . 105n, the pulse signal is reflected at the abnormal location. Therefore, each branch cable 105a, 10
5b, 105c...105n, if the reception times of the reflected signals from the ends of the cables 103 are determined in advance, it is possible to determine that there is an abnormality if the reflected signals are received at times other than these reception times. and branch cables 105a, 105b, 10
5c...105n can be easily inspected. Note that the present invention is not limited to the first embodiment described above. For example, FIG. 5 shows a second embodiment of the invention. In this second embodiment, a multi-gate circuit 111' is used as the reception time measuring circuit of the detection circuit 109 . This multi-gate circuit 111' has a plurality of gates set corresponding to the reception time of the reflected signal from each branch cable 105a, 105b, 105c...105n,
The reflected signals from 5b, 105c, . . . , 105n are configured to be output from respective corresponding gates. Then, the polarity of the reflected wave signal output from each gate is determined by a polarity determination circuit 110,
The signal is configured to be sent to the operating state determination circuit 112. Note that this second embodiment has the same structure as the first embodiment except for the above points, and has the same structure as the first embodiment in FIG.
Parts corresponding to those in the embodiment are given the same reference numerals, and their explanations will be omitted. Further, FIGS. 6 and 7 show a third embodiment of the present invention. In this third embodiment, an amplitude measuring circuit 110' is provided in place of the polarity determining circuit of the second embodiment, and the amplitude of the signal output from each gate of the multi-gate circuit 111' is measured by this amplitude measuring circuit 110'. and is configured to send this to the operating state determination circuit 112'. Then, this operating state determination circuit 112' compares the amplitude of the signal from each gate with the amplitude of the previous signal to determine the difference in amplitude,
From this difference in amplitude, the valves 101a, 101b, 101
c... is configured to monitor the operating state of 101n. In this third embodiment, as shown in FIG.
Each valve 101a, 101b, 101c is smaller than the pulse width _T0 of the pulse signal generated from
...It is capable of detecting the operating state of 101n,
Each branch cable 105a, 105b, 105c...
The difference in length of 105n can be shortened.
That is, as shown in FIG. 7, the multi-gate circuit 11
1', that is, the reflected wave signals from each branch cable 105a, 105b, 105c...105n, is smaller than the pulse width _T0 of the pulse signal, each reflected wave signal is
As shown in the figure, they overlap each other, making it impossible to determine the polarity of these reflected wave signals. However, in this third embodiment, each of the polymerized pulses ~
The amplitude of the signal is measured by an amplitude measuring circuit 110' and sent to an operating state determining circuit 112'. The operating state determination circuit then compares the amplitude of each pulse with the amplitude of the previous pulse to determine the difference. Therefore, if this difference is +1, the polarity of the pulse is positive, and if this difference is -1, the polarity of the pulse is negative. From this, the operating state of each valve 101a, 101b, 101c...101n can be determined. It is. Furthermore, the present invention is not limited to the second embodiment described above; for example, in the embodiment described above, a limit switch was used as the impedance switch, but the impedance switch is not limited to this; It is sufficient if the impedance between the cables can be switched to a value larger or smaller than the impedance of the branch cable and the penetration cable. [Effects of the Invention] As described above, the present invention includes a penetration cable provided through a wall in an air-tight or liquid-tight manner, and a cable branching from the penetration cable for each device whose operating status is to be monitored. A plurality of branch cables consisting of two parallel wires of different lengths are provided, and the impedance between the wires at the tips of these branch cables is adjusted according to the operating state of the above-mentioned equipment provided at the ends of these branch cables. A switch for switching between a state larger and a state smaller than the impedance of the branch cable and the penetration cable, a pulse oscillator that applies a pulse signal to the penetration cable, and a pulse oscillator that applies a pulse signal to the branch cable. The device is equipped with a detection circuit that receives a reflected signal and detects the operating state of the device whose operating state is to be monitored from the polarity and reception time of the reflected signal. Therefore, since the length of each branch cable is different, the reception time of the reflected signal is different for each branch cable, that is, for each device, so it is possible to determine which device the reflected signal corresponds to from the reception time, and Since the polarity of the reflected signal changes depending on the impedance at the tip of the device, the operating state of the device can be determined from the polarity of the reflected signal. Since the branch cable is branched from the penetration cable, even if there are many devices, the penetration cable is only one cable.
It has great effects, such as the fact that it only requires a book and the number of cable penetrations can be reduced, simplifying the structure.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a conventional example. 2 and 3 show a first embodiment of the present invention, FIG. 2 is a schematic diagram of the overall configuration, and FIG. 3 is a schematic diagram showing the connection state of a branch cable and a penetration part cable. Moreover, FIG. 4 is a waveform diagram showing the relationship between the pulse signal and the reflected signal. Moreover, FIG. 5 is a schematic configuration diagram of the second embodiment. Further, FIG. 6 is a schematic configuration diagram of the third embodiment, and FIG. 7 is a waveform diagram of its signals. 101a, 101b, 101c...101n...Valve (device), 103...Penetration part cable, 104...Cable penetration, 105a, 105b, 1
05c...105n...Branch cable, 107a, 1
07b, 107c...107n...Impedance switch, 108...Pulse transmitter, 109 , 109'
...Detection circuit, 113...Display device.

Claims (1)

[Scope of Claims] 1. A penetration cable provided to penetrate a wall in an air-tight or liquid-tight manner, and an interconnection cable branched from the penetration cable and provided corresponding to each device whose operating status is to be monitored. A plurality of branch cables consisting of two parallel wires with different lengths are provided at the ends of these branch cables, and the impedance between the wires at the ends of these branch cables is adjusted according to the operating state of the above-mentioned equipment. A switching device that switches between a state that is larger and a state that is smaller than the impedance of the penetration cable, a pulse oscillator that applies a pulse signal to the penetration cable, and a signal that receives a reflected signal of the pulse signal reflected at the tip of the branch cable. 1. An operating state monitoring device for equipment, comprising: a detection circuit for detecting the operating state of the equipment whose operating state is to be monitored from the polarity and reception time of the reflected signal. 2. The detection circuit includes a multi-gate circuit set in accordance with the reception time of the reflected signal for each branch cable calculated in advance for each branch cable, and this multi-gate circuit determines which device the reflected signal corresponds to. 2. The device operating state monitoring device according to claim 1, wherein the device determines whether the device has been operated. 3. The detection circuit receives signals from a multi-gate circuit set corresponding to the reception time of the reflected wave signal for each branch cable calculated in advance for each branch cable, and each gate of this multi-gate circuit. An amplitude measurement circuit that measures the amplitude of each of these signals, and an operation that receives signals from this amplitude measurement circuit, compares the amplitude of each of the above signals with the amplitude of the previous signal, and determines the polarity of each signal from the difference in amplitude. 2. The device operating state monitoring device according to claim 1, further comprising a state determining circuit.