JPH01313798A - Waste liquid transfer device - Google Patents

Abstract

PURPOSE:To prevent waste liquid from overflowing from a storage tank by providing a high-high liquid level detector for a liquid level high-high arrival alarm, detecting a fault of this detector and a high-high liquid level detector for a pump control, and also, monitoring an operating state of a pump, as well and raising an alarm. CONSTITUTION:When storage of a waste liquid advances and a liquid level rises and reaches a high-high liquid level, a high-high liquid level detector 12 and a second high-high liquid level detector 15 detect it, a start command is generated to both the first and the second pumps 3, 4 of a pump device 2. Also, a liquid level high-high alarm indicator is operated, and it is alarmed to an operator in a central control room that the waste liquid 5 in a sump tank 1 has reached a high-high liquid level. In such a way, a fault of two kinds of liquid level detectors is informed exactly to the operator, and also, an overflow from a storage tank of a waste liquid, etc., can be prevented in advance.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention temporarily stores various waste liquids generated in, for example, nuclear power plants, etc. in a storage tank, and transfers them to a separately installed waste liquid treatment device, etc. The present invention relates to a waste liquid transfer device for

(Prior Art) Generally, various waste liquids generated in a nuclear power plant are separated into radioactive and non-radioactive waste liquids and stored in separate sump tanks. In order to carry out appropriate treatment, the radioactive waste liquid is separated and collected in a different sump tank depending on its properties, and then transferred to a waste liquid processing device that is suitable for its properties. On the other hand, non-radioactive waste liquid is discharged outside the plant.

FIG. 3 is a configuration diagram of a conventional waste liquid transfer device. Radioactive waste liquid generated, for example, at a nuclear power plant is introduced into the sump tank 1 via a waste liquid introduction pipe (not shown). Inside this sump tank 1, a pump device 2 consisting of two pumps, a first pump 3 and a second pump 4, is installed.
is configured to be transferred to a waste liquid treatment device 7 via a waste liquid transfer pipe 6.

The sump tank 1 is provided with a liquid level detection device 8 consisting of a low liquid level detector 9, a low liquid level detector 10, a high liquid level detector 11, and a maximum liquid level detector 12. Each preset liquid level in the sump tank 1 is detected by the level detection device 8. Each output signal from the liquid level detection device 8 is inputted to a control device 13, which controls starting and stopping of the pump device 2.

That is, both the first pump 3 and the second pump 14 are stopped in response to low and low liquid level signals, and one unit of either the first pump 3 or the second pump 4 is stopped in response to a high liquid level signal. Drive alternately. In response to the liquid level signal, a signal No. 13 for operating the first pump 3 and the second pump 4 is output, and an alarm is issued indicating that the liquid level has reached the maximum level. In this way, the maximum liquid level detector 12 functions as backup protection equipment for the high liquid level detector 11.

(Problem to be Solved by the Invention) However, if at most the liquid level detector 12 in the liquid level detecting device 8 fails, the signal from the high liquid level detector 11 will cause the Even if the first pump 3 is operated, the liquid level in the sump tank 1 continues to rise, and even if the liquid level reaches at most, the second pump 4 is not activated, and an alarm that the liquid level has reached at most is issued. do not have. As a result, there was a drawback that the tIl-emitting waste liquid 5 overflowed from the sump tank 1. In the unlikely event that radioactive waste liquid 5 overflows, radioactive contamination within the building and radiation exposure of workers are expected. There was also the problem that if this overflow was not noticed, the damage would spread rapidly.

The present invention has been made in view of the above, and its purpose is to provide a second maximum liquid level detector for warning of reaching the maximum liquid level in addition to a maximum liquid level detector for pump control. Detects a failure of the maximum liquid level detector and the maximum liquid level detector for controlling the pump, and also monitors the operating state of the pump and issues an alarm;
An object of the present invention is to provide a waste liquid transfer device that does not cause overflow.

[Structure of the Invention] (Means to be Solved by the Invention) A liquid level detection device that detects that waste liquid in a storage tank for storing waste liquid reaches a preset liquid level and issues a waste liquid transfer command, and a storage tank. The liquid level in the storage tank is controlled at most by a waste liquid transfer device consisting of a pump device consisting of a plurality of pumps for transferring the waste liquid inside the storage tank to the outside, and a control device that controls the operation of the pump device based on the output signal of the liquid level detection device. a second maximum and maximum liquid level detector that detects and outputs an alarm signal; a maximum and maximum liquid level detector in the liquid level detection device and a second maximum and maximum liquid level detector based on this alarm signal and an operation signal of the pump device; The system is equipped with a failure detection device that detects and notifies a failure of the system.

(Function) When the liquid level of the waste liquid in the storage tank rises due to the inflow of waste liquid and reaches the preset maximum liquid level, under normal conditions, the pump is activated by a signal from the maximum liquid level detector in the liquid level detection device. Multiple operation commands are issued, and a maximum liquid level reaching alarm is issued by a signal from the second maximum liquid level detector.

If the maximum liquid level detector in the liquid level detection device is malfunctioning in an abnormal situation, a command to operate all pumps will not be issued, but the failure detection device will issue an alarm signal from the second maximum liquid level detector. After confirming that there is no signal indicating that all pumps are in operation, a liquid level reaching high alarm and a high liquid level detector failure alarm are issued. In addition, if the second high-water level detector fails, the liquid level at-high warning is not output, and only the failure notification of the high-water level detector is issued. As a result, the failure of the high-water level detector is confirmed. Since the operating status of the pump device etc. at this time can be determined, prompt and appropriate maintenance measures can be taken to prevent waste liquid from overflowing from the storage tank.

(Example) An example of the present invention will be described with reference to the drawings. Note that the same components as those in the prior art described above are given the same reference numerals and detailed explanations will be omitted.

FIG. 1 shows a block diagram of the waste liquid transfer device. Store waste liquid 5 J
A first pump 3 and a second pump are installed in a sump tank 1, which is a storage tank.
A pump device 2 consisting of a pump 4 is installed, and this pump device 2 and a waste liquid treatment device 7 are communicated via a waste liquid transfer pipe 6.

Further, the sump tank 1 is provided with a liquid level detecting device 14, and the liquid level detecting device 14 detects the preset liquid level in the sump tank 1 by operating the two pumps 3 of the pump system @2. Low and low liquid level detector 9 that outputs a stop command to .4
and a low liquid level detector 10, a high liquid level detector 11 that issues an operation command for one of the pumps in the pump device 2, and a first liquid level detector 12 that outputs an operation command for the two pumps. , and a second high-water level detector 15 which outputs a high-water level alarm signal. In addition, a control device 16 that controls operation and stop of the pump device 2 based on the signal from the liquid level detection device 14 and a signal from the liquid level detection device 14 are input,
Liquid level maximum alarm and first and second maximum liquid level detectors 12
．． 15, and a failure detection device 17 that performs failure detection and notification.

The circuit diagram in FIG. 2 shows the main parts of the control device 16 and the failure detection device 1.
The configuration of 7 is shown in . Note that a description of the control circuit for the pump device 2 connected to the control device 16 and failure detection device 17 will be omitted. The control devices 16 each have a common control power source P.
, N, there is a series circuit consisting of a low and low liquid level contact 9B and a relay 20 which are opened when activated by the operation signal of the low and low liquid level detector 9, and a low liquid level contact which is closed by the operation of the low and low liquid level detector 10. A series circuit between the high level contact 10B and the relay 21, a series circuit between the high liquid level contact 11A and the relay 22 which is closed by the operation of the high liquid level detector 11, and a series circuit which is closed by the operation of the first high liquid level detector 12. At most liquid level contact 12
A and a series circuit of relay 23, contact 20b that opens when relay 20 is energized, and contact 21 that opens when relay 21 is energized.
b, a circuit in which a contact 23a that opens when the relay 23 is energized and a relay 24 are connected in series, and a contact 24a1 that closes when the relay 24 is energized is connected in parallel to the contact 23a;
A series circuit of a liquid level alarm contact 15A and a relay 25 which are closed when activated by the operation signal of the second liquid level detector 15 at maximum, a contact 25a1 which is closed by the excitation of this relay 25, and a liquid level at maximum alarm indicator. A series circuit with 26 is connected.

Next, the failure detection device 17 connects the control power supplies P and N to a contact 3A that is closed by the operation signal of the first pump 3, a contact 4A that is closed by the operation signal of the second pump 4, and a relay 30.
A relay 25 connected in series with a contact 30b1 which opens when the relay 30 is energized and a liquid level alarm contact 15A which closes when the liquid level in the control device 16 is high is energized and closes J. The contacts 25a2 are connected in series, and the contact 30a2 is closed when the relay 30 is excited, and the contact 2 is opened when the relay 25 in the control device 16 is excited.
Connect the series circuit of 5b3 in parallel and connect relay 3 to this.
1 are connected in series, and a series circuit of a contact 31a and a failure indicator 32, which are closed when the relay 31 is excited, is connected. In addition, the liquid level high alarm indicator 26
The and failure indicators 32 are generally placed in a central control room, and provide indications or alarms using indicator lights or buzzers, depending on the signals inputted to each unit.

The effect of the above configuration will be explained. Sump tank 1
The waste liquid 5 introduced into the tank is gradually stored and its liquid level rises. When the preset liquid level low and low liquid level is reached,
The low/low liquid level detector 9 and the low liquid level detector 10 sequentially detect this, and the low/low liquid level contact 9B and the low liquid level contact 103, which had been closed until then, are opened. This allows relays 20 and 2
1 is released and contacts 20b and 21b are closed. Note that at this point, two pumps 3.
4 is stopped. When the waste liquid 5 gradually accumulates and the liquid level rises to reach the liquid level high, the high liquid level detector 11 detects this and closes the high liquid level contact 11A, and the relay 22 is energized and the contact is closed. 22a is closed and the pump in the pump device 2 is
Drive the machines alternately. However, if the amount of waste liquid flowing in is large, the liquid level will rise further and eventually reach the highest liquid level and reach the first level.
The maximum and maximum liquid level detector 12 and the second maximum and maximum liquid level detector 15 detect this, and close the maximum and maximum liquid level contact 12A and the liquid level alarm contact 15A, which are output signals, and relays 23 and 25
Excite. As a result, contact 23a closes and relay 2
4 is energized, contact 24al closes, and relay 24
form a holding circuit. Note that a start command is issued to both the first and second pumps 3.4 of the pump device 2 by the contact 24a2 which closes at the same time as the contact 24a1. At the same time, the contact 25a1 of the relay 25 is closed, and the liquid level high warning indicator 26 is activated to alert the operator in the central control room that the waste liquid 5 to be poured into the sump tank 1 has reached the liquid level at most. do.

At this time, both the first maximum liquid level detector 12 and the second maximum liquid level detector 15 are in a normal state. In the failure detection device 17, as described above, the first pump 3 and the second pump 4 are started and operated, the contacts 3A and 4A are closed, the relay 30 is energized, the contact 30bl is opened, and the contact 30a2 is opened. Close. However, the control device 1 that forms a series circuit with this
Since the contacts 25a1 and 25b2 of the relay 25 of No. 6 are closed and opened, respectively, a conductive circuit is not formed and the relay 31 is not excited, so the contact 31a remains open. Naturally, the fault indicator 32 is not activated.

Next, a case will be described in which the first maximum liquid level detector 12, which issues a start command to the pump device 2, fails.

Even if the liquid level of the waste liquid 5 reaches the highest level, if the first high-high level detector 12 is out of order, the liquid level high-high contact 12A, which is its output signal, will not be closed and the relay 23 will not be energized. The contact 23a is open, the relay 24 is not operated, and the contact 24a2 does not issue a two-pump operation command to the pump device 2. Therefore, the pump device 2 is still operating the pumps alternately according to the command from the high liquid level detector 11. Since one unit continues to operate, only one of the contacts 3A and 4A in the failure detection device 17, which is the operating signal, is always closed.

As a result, the relay 30 is not energized, its contact 30bl is closed, and its contact 30a2 is open.

However, the second high-water level detector 15 that outputs the liquid level high-high alarm signal is normal and closes the liquid level alarm contact 15A when the liquid level is high, so the relay 25 is energized and the contact 2
5a1 is closed and a warning is notified to the operator from the liquid level high warning indicator 26. Roughly speaking, in the failure detection device 17, since the contact 25a2 and the contact 25b3 of the relay 25 are closed and opened, respectively, the internal contact 25a2 and the contact 3 are closed and opened, respectively.
The relay 31 is excited by the circuit of 0bl, and the contact 31a
closes and activates the failure indicator 32 to notify that at most the liquid level detector is out of order.

That is, when both the high liquid level alarm and the failure alarm are reported, the first high liquid level detector 12 is out of order and the operator needs to repair it, and only one transfer pump is in operation. Moreover, the waste liquid 5 has reached the liquid level in the sump tank 1 at most, and it can be seen that if urgent measures are not taken, an overflow of the waste liquid 5 will occur sooner or later.

If the second high-water level detector 15 fails, the first high-water level detector 12 detects this when the waste liquid 5 reaches the high water level, and closes the liquid level high-water contact 12A. The relay 23 is energized and the contact 23a is closed. For this reason, relay 24
is excited, the contact 24a1 closes and holds itself, and the contact 24a2 also closes, starting the two pumps 3 and 4 of the pump device 2. On the other hand, the second high-high liquid level detector 15 fails and does not close the liquid level alarm contact 15A, so the relay 25 is not energized and the contact 25a1 remains open, and the liquid level high-high alarm indicator 26 is activated. Therefore, no alarm is issued.

However, in the failure detection device 17, the first pump 3 and the second pump 4 of the pump device 2 are
As a result, both contacts 3A and 4A, which are operation signals, are closed, so the relay 30 is energized and its contacts 30bl are opened and their contacts 30a2 are closed. do. Contact 25a2 of the unexcited relay 25 in this circuit is open, contact 25b3
is closed, so this inner contact 25b3 and contact 30a
A circuit No. 2 is formed and the relay 31 is energized, so that its contact 31a is opened, the failure detection device 32 is activated, and a failure alarm of the high and high liquid level detector is issued.

In other words, when the alarm is only a failure alarm and there is no liquid level high alarm,
The second maximum liquid level detector 15 has failed and the operator has confirmed that it needs to be repaired and that the liquid level has reached maximum, but the pump device 2 is normal and two pumps are in operation. I can see that

[Effect of the invention 1] According to the present invention, in a waste liquid transfer device that transfers waste liquid stored in a storage tank such as a sump tank to the outside as appropriate depending on the liquid level, the liquid level of the waste liquid, particularly the maximum liquid level of the storage tank etc. It is possible to separately detect failures of the two types of liquid level detectors, issue an alarm, and accurately notify operators, and prevent overflow of waste liquid from storage tanks, etc. It has the effect of improving reliability and safety by preventing radiation contamination and radiation exposure when used in nuclear power plants.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an embodiment of the waste liquid transfer device of the present invention;
The figure is a circuit diagram of the main parts of the control device and failure detection device shown in FIG. 1, and FIG. 3 is a configuration diagram of a conventional waste liquid transfer device. 1...Sump tank 2...Pump device 3A・
... First pump operation contact 4A... Second pump operation signal contact 9B... Low and low liquid level contact 10B... Low liquid level contact 11A... High liquid level contact 12. ...First maximum and maximum liquid level detector 12A ... Maximum liquid level contact 14 ... Liquid level detection device 15 ... Second maximum and maximum liquid level detector 15A ... Liquid level alarm contact 16 ... Control device 17
...Failure detection device 26...Liquid level high alarm indicator 32...Failure indicator Representative Patent attorney Norihiko Ogo Fumata 1st prisoner Figure 3

Claims (1)

[Claims] A storage tank for storing waste liquid, a liquid level detection device installed in this storage tank to detect when the waste liquid in the storage tank has reached a preset liquid level, and a plurality of pumps for transferring the waste liquid in the storage tank to the outside. In the waste liquid transfer device comprising a pump device and a control device that controls the operation of the pump device based on the output signal of the liquid level detection device, a second liquid at most detects the liquid level at most in the storage tank and outputs an alarm signal. and a failure detection device that detects and notifies a failure of a maximum liquid level detector and a second maximum liquid level detector in the liquid level detection device based on the alarm signal and the operation signal of the pump device. A waste liquid transfer device characterized by: