JP2885429B2 - Valve opening and closing control device for water treatment equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a valve opening / closing control device for controlling the opening / closing of a treated water inlet valve and a treated water outlet valve of a valve opening / closing control device of a water treatment facility, More specifically, the present invention relates to a valve opening / closing control device having a fail-safe function for preventing a treated water inlet valve and a treated water outlet valve from closing due to runaway of a digital control system or the influence of noise or the like.

[Prior Art] Conventionally, in a condensate purification system, a reactor coolant purification system, and a fuel pool cooling purification system of a nuclear power plant, a filtration and desalination apparatus using a precoating agent such as powder ion exchange resin and a hollow membrane are used. A water treatment facility including various filtration devices typified by filtration devices or various desalination devices filled with a granular ion exchange resin is installed.

In the condensate purification system of thermal power plants, various types of desalination devices that are filled with granular ion-exchange resin are used alone, or water that combines electromagnetic filters and filtration devices that use various precoating agents before and after it is used. Processing equipment is installed,
Further, various water treatment facilities mainly including a reverse osmosis membrane device are installed in a semiconductor production plant.

The above-described various devices used in these water treatment facilities are inevitably interrupted during, for example, regeneration of the device. Therefore, the treated water inlet valve and the treated water are provided at the inlet and the outlet of the device. It is necessary for operation management to provide an outlet valve and open and close both valves.

FIG. 3 shows a layout of a steam turbine power plant such as a nuclear power plant or a thermal power plant. The steam generated in the steam generator I drives the high-pressure turbine II and the low-pressure turbine III,
It is cooled by condenser IV and becomes condensed water.

The condensate from the condenser IV is sent by a low-pressure condensate pump V to a condensate filtration device VI and a condensate desalination device VII, which are valves that control the opening and closing of the water treatment equipment, and filter the condensate. The water is supplied to the low-pressure heater IX by the high-pressure condensate pump VIII, and further supplied to the steam generator I through the high-pressure heater XI by the water supply pump X.

FIG. 4 is a schematic diagram of a condensate filtration unit VI and a condensate desalination unit VII. The condensate filtration unit VI operates in parallel with a plurality of filtration towers (hereinafter referred to as CF towers) VI-1 to VI-n. And the condensate desalination unit VII includes a plurality of desalination towers (hereinafter referred to as CD towers) VII-1 to VI
In parallel operation is performed by In.

The condensate filtration device VI has a regeneration treatment device for regenerating the filter material in each CF column, and the condensate desalination device VII has a regeneration treatment device for regenerating the ion exchange resin in each CD column. For example, when the tower pressure difference of the CF tower rises above a predetermined value or when the condensate flows through the CD tower at a constant yield, each CF tower and each CD tower are stopped in order to stop water sampling to the tower. The treated water inlet valve CFVI, treated water outlet valve CFVO and the treated water inlet valve CDVI, treated water outlet valve CDVO are closed, and the regeneration process is performed on both the CF tower and the CD tower.

In the CF tower, various steps are performed in accordance with the order shown in FIG. 6 in order to sample and filter condensed water to be treated while repeating the regeneration step. First, the instruction of "stop" is required, and by the instruction of "stop", the treated water inlet valve CFVI and the treated water outlet valve CFVO of the CF tower are closed to the fully closed position to stop water sampling,
The regeneration process is executed according to the instruction of "regeneration", and when the regeneration process is completed and "water sampling" is instructed, water can be sampled, that is, the preparation process before water sampling is performed, and the treated water inlet valve of the CF tower
A water sampling process is performed in which CFVI and treated water CFVO are opened and condensate flows through the CF tower.

In addition, the CD column is also used for desalination of filtered condensate while repeating the above-mentioned regeneration step.
As shown in the figure, in order to regenerate during the water sampling process, first, "stop" is instructed, the treated water inlet valve CDVI and the treated water outlet valve CDVO of the CD tower are closed to the fully closed position, and thereafter, "Regeneration"
When the regeneration process is executed by instructing, and after the regeneration process is completed, a "stop" is instructed, and then, when "water sampling" is instructed, the circulating water is circulated in the CD tower filled with the regenerated resin. After that, a water sampling step is performed in which the treated water inlet valve CDVI and the treated water outlet valve CDVO of the CD tower are opened and condensate flows through the CD tower.

Each CF in the above-mentioned condensate filtration device and condensate desalination device
The process of water sampling, regeneration, and water sampling of the tower and CD tower is centrally controlled by, for example, a control panel installed in the control room. On the control panel, "water sampling" and "stop ","Regeneration"
Switches for water condensing, desalting, "stop" and "regeneration" are arranged. By turning on the above switches, the programmable logic controller (PLC), digital process control system (DPCS), a digital control system such as a personal computer (PC) executes the flow shown in FIG. 6 and, for example, an actuator for opening and closing a treated water inlet valve and a treated water outlet valve of a CF tower and a CD tower, for example, a motor. To output the valve fully closed output signal and the valve fully open output signal to open the treated water inlet valve,
Close the treated water outlet valve.

FIG. 6 is a block diagram of a system for closing the treated water inlet valve.

Reference numeral 1 denotes a digital control system comprising a programmable logic controller. In the figure, a system for closing the treated water inlet valve is indicated by a logical symbol, and a signal from a stop switch 2 is input to an input terminal DI1, and The signal from the water sampling switch 3 is input to the input terminal DI3, and the output from the output terminal DO1 is output to one input terminal of the external AND circuit 4. When pressed and turned on, a "1" signal is output for one pulse.
The digital control system 1 scans an input signal at a predetermined cycle, and when the stop switch 2 is turned on, a pulse signal of “1” is output by one pulse.
-1 is output for one pulse, a flag is set in the stop signal storage area 1-1 to indicate a stop process, and the signal of "1" is output from the stop signal storage area 1-1 to the latch mechanism 1.
Input -2 on the left side of the set side. When a pulse signal of "1" is input to the left of the set (S) side, the latch mechanism 1-2 continues to output a signal of the right side of the set until a pulse of "1" is input to the left of the reset (R) side. Has become. Therefore,
From the right side of the set of the latch mechanism 1-2, until a signal of "1" indicating the water sampling step is input from the water sampling switch 3 to the reset left side of the latch mechanism 1-2 via the input terminal DI3.
The signal of “1” indicating the stop process and the output signal of the inlet valve being fully closed continues to be output. This signal is output from the output terminal DO1 to one input side of the external AND circuit 4. However, when the inlet valve changeover switch 5 is switched to the automatic side, the other input of the external AND circuit 4 is output. The signal of “1” is output to the side, and the signal of “1” is output from the external AND circuit 4 to the external OR circuit 6. When a signal of "1" is output from the external OR circuit 6, the inlet valve fully closed output relay 7 operates so that the actuator for driving the water inlet valve is driven in the direction to close the water inlet valve. Then, the treated water inlet valve is fully closed. When the inlet valve changeover switch 5 is switched to manual operation and the inlet valve close switch is operated, “1” is output to the external OR circuit 6.
Is output, and the treated water inlet valve is fully closed manually.

The control of the treated water outlet valve is basically the same as the operation of the treated water inlet valve described above.

[Problems to be Solved by the Invention] In FIG. 6, the digital control system 1 transmits and receives signals to and from the outside by using a photocoupler or the like in order to prevent malfunction due to external noise or the like. When the "stop" flag is set in the stop signal storage area 1-1 due to a memory write error, a signal transmission error, noise, or the like of the digital control system itself, an output signal of the inlet valve fully closed is erroneously output from the output terminal DO1. During the automatic operation, a signal of "1" is output from the external AND circuit 4, and the treated water inlet valve of the filtration device or the desalination device is fully closed in spite of the water sampling process. Similarly, the treated water outlet valve may be completely closed during the water sampling process.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional problem. A failure occurs in a digital control system during a water sampling process, and a treated water inlet valve and a treated water outlet valve are closed. A valve opening / closing control device for water treatment equipment that can maintain a valve open state without instructing the actuators of the treated water inlet valve and treated water outlet valve to drive in the valve closing direction even if they malfunction in the direction. Is to provide.

[Means for Solving the Problems] A typical configuration for achieving the object of the present invention is a water treatment facility having a treated water inlet valve and a treated water outlet valve that is driven to open and close by an actuator. Are individually input, and when the stop operation is input, the stop operation is determined to have been instructed, the stop operation signal storage unit that outputs the stop operation signal is provided, and the plurality of stop operation signal storage units are output. And a digital control system having a plurality of valve-closing signal output units that output a stop operation signal as a valve-closing signal until a water-dispensing signal is supplied from a water-dispensing switch when all of the signals are stop operation signals. A circuit that outputs a valve-closing signal when all of the signals from the plurality of valve-closing signal output units are valve-closing signals; and a circuit that outputs the signal until the stop signal from the stop switch is input. A latch mechanism for outputting a water sampling signal from the water switch, and as long as the water sampling signal from the latch mechanism is input, the output of the circuit is output to the actuator even if the output of the circuit is a valve closing signal. And a valve closing control circuit for the water treatment facility.

[Operation] The valve opening / closing control device of the water treatment facility configured as described above includes:
Even if a trouble occurs in one of the stop operation signal storage units or a stop signal is input by mistake in the digital control system itself, as long as the other stop operation signal storage units are normal, the stop operation signal will be output to the digital control system. Even if a valve closing signal is output due to some trouble on the subsequent stage of the stop operation signal storage unit, the valve closing signal output unit is multiplexed again and one output signal is closed. If it is not a signal, no valve closing signal is output to the next stage. Further, even if all of the plurality of outputs from the digital control system are valve closing signals, the valve closing preventing circuit prevents the valve closing signal from being output to the actuator during sampling.

EXAMPLES Hereinafter, the present invention will be described in detail based on examples shown in the drawings.

Embodiment 1 FIG. 1 is a block diagram showing Embodiment 1 of a valve opening / closing control device for a water treatment facility according to the present invention. The same components as those in the conventional example shown in FIG. Description is omitted.

This embodiment shows a control system for controlling the opening and closing of the water inlet valve as in the conventional example shown in FIG. 6, and the digital control system 1 is configured in the same manner as the conventional example.
A signal from the stop switch 2 is input to the reset side of the external latch mechanism 10, and a set-side output signal of the latch mechanism 10 is input to the C side of the wipe-out circuit 11. The output signal of the external AND circuit 4 is A
The signal on the B side is output to one input side of the OR circuit 6. When the signal on the C side is "1", even if the input signal on the A side is "1", If the output signal on the A side is “0” and the signal on the C side is “0”, if the input signal on the A side is “1”, the output signal on the B side is “1” and the input signal on the A side If the signal is “0”, the output signal on the B side becomes “0”.

That is, the input terminal DI1 of the digital control system 1
Since the "0" signal is input from the stop switch 2 to the stop signal storage area 1-1 of the stop signal storage unit, no flag indicating "stop" is set, and the internal latch mechanism 1-
2 outputs a signal of "0", an output terminal DO1 of the digital control system 1 outputs a signal of "0" to one input side of the external AND circuit 4, and the inlet valve selector switch 5 is turned off automatically. If it is changed, a signal of “1” is input to the other input side of the external AND circuit 4, but “0” is input from the external AND circuit 4 to the A side of the wipe-out circuit 11.

On the other hand, on the set side of the external latch mechanism 10, a signal of "1" indicating that the water sampling process is being performed is input from the water sampling switch 3 to the set side of the external latch mechanism 10, and the reset of the external latch mechanism 10 is performed. Is input from the stop switch 2 to the C side of the wipe-out circuit 11, and “1” is input to the C side of the wipe-out circuit 11, and a signal of “0” is input from the B side of the wipe-out circuit 11 to the OR circuit 6. The OR circuit 6 outputs a "1" signal to the inlet valve fully closed output relay 7 unless the manual instruction to close the inlet valve selector switch 6 is given. The treated water inlet valve is kept open.

Therefore, even though the water sampling process is in progress, the digital control system 1 causes the output terminal DO1 due to some trouble.
Even if a signal of "1" which is an output signal of the inlet valve being fully closed is output from "1", since "1" is input to the C side of the wipe-out circuit 11, from the B side of the wipe-out circuit 11, Even if a signal of "1" is input to the A side, a signal of "0" is output and the inlet valve fully closed output relay 7 is not operated.

Second Embodiment FIG. 2 is a block diagram showing a second embodiment of the valve opening / closing control device for water treatment equipment according to the present invention. Omitted.

In this embodiment, the digital control system, the input / output and the memory in the first embodiment are duplicated. The digital control system 1 'has two inputs to which signals from the stop switch 2 are separately input. Terminals DI1 and DI2 are provided, and two output terminals DO1 and DO2 are provided.
When a stop signal of "1" is input from the stop switch 2 to the input terminal DI1, the first stop signal storage area 1-1
The stop signal storage unit outputs a "1" signal, which is an inlet valve fully closed output signal, to one input side of the AND circuit 1-3, and stops the "1" from the stop switch 2 at the second input terminal DI2. When a signal is input, the second signal comprising the stop signal storage area 1-1 'is generated.
Is configured to output a signal of "1", which is an output signal of the inlet valve fully closed, to the other input side of the AND circuit 1-3. The output of the AND circuit 1-3 is the latch mechanism 1
-2, which is input to the set side and is the set-side output of the latch mechanism 1-2, is divided into two and output to the output terminals DO1 and DO2, respectively. Output signals from the output terminals DO1 and DO2 of the digital control system 1 'are output to both input sides of the second external AND circuit 12, and the output of the second external AND circuit 12 is output to the first external AND circuit 4. Is output to one input side.

According to such a configuration, the first and second stop signal storage units in the digital control system 1 'store the stop signal during the water sampling process unless the stop switch 2 is turned on as in the first embodiment. The flag "1" is not set in the areas 1-1 and 1-1 ', the output of the AND circuit 1-3 is "0", and the output terminals DO1 and DO2 both output a signal of "0". The output of the external AND circuit 12 becomes “0” and the inlet valve selector switch 5
Is an automatic signal, the first external AND circuit 4 outputs a signal of "0".

That is, even though the stop switch 2 is not turned on, the probability that a trouble occurs simultaneously in the first stop signal storage section and the second stop signal storage section of the digital control system 1 'is extremely rare, and the output is also low. Due to the duplexing, even if a trouble occurs in the first stop signal storage unit and is output to one input side of the AND circuit 1-3, for example, the second
Since the output of the stop signal storage unit is "0", the AND circuit 1-
3 is "0" and the signal of "1" is output to the latch mechanism 1-2.
And even if a trouble occurs between the output side of the latch mechanism 1-2 and the output terminals DO1 and DO2,
Unless a signal “1” is output from the output terminals DO1 and DO2 at the same time, a signal “1” is not output from the second external AND circuit 12.

On the other hand, the signal from the stop switch 2 is also output to the reset side of the external latch mechanism 10 and output to the reset side of the external latch mechanism 10 as in the first embodiment.
The ten set-side output signals are output to the C side of the wipe-out circuit 11, the output of the first external AND circuit 4 is output to the A-side of the wipe-out circuit 11, and the B-side output of the wipe-out circuit 11 is output. Is input to one input side of the OR circuit 6.

That is, during the water sampling process, although there is a probability that cannot actually be realized, a trouble occurs in the digital control system 1 ', and a signal of "1" is simultaneously generated from the two output terminals DO1 and DO2. Even if a signal of “1” is output from the external AND circuit 4, the signal on the C side of the wipe-out circuit 11 is “1”.
Is output, and the inlet valve fully closed output relay 7 does not operate to the inlet valve fully closed side.

In each of the embodiments described above, the treated water inlet valve has been described as an example, but the valve opening / closing control is also performed on the treated water outlet valve by the same device.

Further, it is needless to say that each of the above-described embodiments can be applied to a case where the water treatment equipment is only a filtration device or a desalination device, or a case where both the filtration device and the desalination device are combined as shown in FIG. There is no such thing.

[Effects of the Invention] As described above, according to the first invention, even if a trouble occurs in the digital control system itself and a valve closing signal is output during the water sampling process, the valve closing prevention circuit section. This prevents the valve closing signal from being output to the actuator.

According to the second aspect, since the stop operation signal storage unit and the valve closing signal output unit in the digital control system are multiplexed, for example, duplicated, the reliability of the digital control system can be improved, and the digital control system can be improved. Even if an erroneous signal is input or a trouble occurs in one of the stop operation signal storage unit and valve closing signal output unit in the digital control system, a valve closing signal may be output to the actuator during the water sampling process. Without increasing the reliability of the first invention,
The reliability is extremely high.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of a valve opening / closing control device for water treatment equipment according to the present invention, FIG. 2 is a block diagram showing a second embodiment, FIG. 3 is a layout diagram of a steam turbine power plant, FIG. The figure is a schematic diagram of a condensate filtration device and a condensate desalination device, FIG. 5 is a diagram showing steps of a condensate purification system water treatment equipment, and FIG. 6 is a block diagram of a conventional valve opening / closing control device. . 1, 1 ': Digital control system 2: Stop switch, 3: Water sampling switch 4: External AND circuit 5: Inlet valve changeover switch 6: OR circuit 7: Inlet valve fully closed output relay 10: Latch mechanism 11: Wipeout circuit 12: AND circuit I: Steam generator, II: High pressure turbine III: Low pressure turbine, IV: Condenser V: Low pressure condensate pump, VI: Condensate filtration device VII: Condensate desalination device, VIII: High pressure condensate Pump IX: Low pressure heater, X: Feed water pump XI: High pressure heater VI-1 to VI-n: Filtration tower (CF tower) VII-1 to VII-n: Desalination tower (CD tower) CFVI, CDVI: Treated water Inlet valves CFVO, CDVO: Treated water outlet valve.

Continued on the front page (72) Inventor Toshinobu Irisaka 5-5-16-1 Hongo, Bunkyo-ku, Tokyo Organo Corporation (72) Inventor Shuta Oshima 5-5-16-1 Hongo, Bunkyo-ku, Tokyo Organo Corporation (72) Inventor Yuichi Ishizaka 5-6-116 Hongo, Bunkyo-ku, Tokyo Organo Co., Ltd. (56) References JP-A-61-213697 (JP, A) (58) Fields investigated (Int. . ^6, DB name) C02F 1/00 G21F 9/12 512 G05B 9/02

Claims (2)

(57) [Claims] In a water treatment facility having a treated water inlet valve and a treated water outlet valve driven to open and close by an actuator, when a stop signal is input from a stop switch, it is determined that a stop operation has been instructed and a stop operation is performed. A digital control system including a stop operation signal storage unit that outputs a signal, and a valve closing signal output unit that outputs a stop operation signal as a valve closing signal until a water sampling signal is supplied from the water sampling switch; and A latch mechanism for outputting a water sampling signal from the water sampling switch until a stop signal is input, and as long as the water sampling signal is output from the latch mechanism, the output of the digital control system is a valve closing signal. And a valve closing prevention circuit that does not output the output of the digital control system to the actuator. Place. 2. In a water treatment facility having a treated water inlet valve and a treated water outlet valve driven to open and close by an actuator, a stop signal from a stop switch is individually input, and the stop operation is performed when the stop signal is input. A plurality of stop operation signal storage units that output a stop operation signal when it is determined that the stop operation signal has been instructed, and a water sampling signal from the water sampling switch when the signals from the plurality of stop operation signal storage units are all stop operation signals. Digital control system having a plurality of valve closing signal output unit that outputs a stop operation signal as a valve closing signal until is given,
A circuit for outputting a valve-closing signal when all signals from a plurality of valve-closing signal output units of the digital control system are valve-closing signals; and a circuit from the water sampling switch until a stop signal from the stop switch is input. A latch mechanism that outputs a water sampling signal, and valve closing prevention that does not output the output of the circuit to the actuator even if the output of the circuit is a valve closing signal as long as the water sampling signal from the latch mechanism is input. A valve opening / closing control device for a water treatment facility, comprising a circuit.