JPH0772283A - Condensate make-up water device - Google Patents

Abstract

PURPOSE:To provide a condensate make-up water device which prevent generation of hunting in measured indication values by monitoring water altogether after sufficiently mixing reservoir water and excess water in a condensate reservoir equipment or monitoring along the reservoir water. CONSTITUTION:A condensate make-up water device 22 supplies control water load 12 with the reservoir water 17 of a condensate reservoir equipment 15 and the excess water of a condensate demineralizing device 6 altogether as plant make-up water 16. Between the condensate reservoir equipment 15 and the load 12, a water supply piping 14 provided on the way with a condensate transportation pump 13 and a water monitoring device 19 is connected. Upstream the condensate transportation pump 13 in the water supply piping 14, a connection piping 10 having a check valve 23 is connected with the condensate demineralizing device 6 and a return water piping 24 is connected in between the upstream of the check valve 23 and the condensate reservoir equipment 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control water supply system in a nuclear power plant, and more particularly to a condensate replenishment water system which facilitates monitoring of the water quality of plant makeup water.

[0002]

2. Description of the Related Art In a conventional condensate makeup water supply system, a main steam 2 generated in a reactor pressure vessel 1 of a main steam system drives a turbine 3 as shown in a schematic configuration diagram of a main part of a nuclear power plant in FIG. After this, the water is condensed in the condenser 4 and becomes condensed water 5. Thereafter, the condensate 5 is purified by the condensate demineralizer 6 and constitutes a closed loop which returns to the reactor pressure vessel 1 again.

The main steam system also includes (1) recirculation pump purge water, (2) reactor coolant purification system pump purge water,
(3) Control rod drive system cooling water, (4) Condenser make-up water, (5) Grand steam purifier make-up water, etc. flow in from the outside, but these are excess water for the main steam system. is there.

Therefore, a flow rate corresponding to the surplus makeup water or the like is branched from the outlet side of the condensate demineralizer 6 to discharge a constant flow rate to the outside of the main steam system. Note that, hereinafter, this discharged water is referred to as return water from the condensate desalination device 6. Further, this return water supplies a constant flow rate to the control rod drive system load 8 as a water source of the control rod drive water pump 7. However, since there is a relation of “return water> supply of control rod drive water pump”, Part of the return water (dotted arrow) 9 is supplied as excess water to each load 12 of the condensate makeup water system of the condensate makeup water system 11 via the connecting pipe 10.

As described above, a part of the return water 9 is constantly supplied to the condensate makeup water system side at a constant flow rate. On the other hand, the load 12 of the condensate makeup water system has various usage frequencies and usage flow rates. is there. For example, when the load 12 of the condensate makeup water system requires almost no supply water, “the discharge amount of the condensate transfer pump 13 <
Part 9 of the return water, and for this reason part 9 of the return water
The water may flow back through the water supply pipe 14 and be sent to the condensate storage facility 15.

The water supplied to each load 12 of the condensate makeup water system will be hereinafter referred to as plant makeup water and indicated by a white arrow 16. In addition, when the required amount of the plant makeup water 16 at the load 12 of the condensate makeup water system increases, it is not possible to supply all the required amount with only a part of the return water 9. The stored water (solid arrow) 17 of the facility 15 is supplied, and both are mixed and supplied as plant makeup water 16 to the load 12 of the condensate makeup water system.

Therefore, the plant make-up water 16 supplied to the load 12 of the condensate make-up water system is the stored water 17 from the condensate storage facility 15.
And a part 9 of the return water from the condensate demineralizer 6 are mixed, and the mixing ratio changes as the demand state of each load 12 of the condensate makeup water system changes. .

Further, as shown in the configuration diagram of FIG. 5, in the conventional condensate replenishment water system 11, part of the plant replenishment water 16 supplied to the load 12 of the condensate replenishment water system is reconstituted with respect to water quality monitoring. Water is branched from a water sampling point 18 downstream of the transfer pump 13 and led to a water quality monitoring device 19 for continuous water quality monitoring.

A part of the plant makeup water, whose water quality has been monitored, returns to the return point 20 upstream of the condensate transfer pump 13 to form a closed loop. Condensate storage facility 15
Purified treated water from the waste treatment system 21 is separately introduced into.

[0010]

DISCLOSURE OF THE INVENTION Condensate make-up water device
In 11, the plant makeup water 16 flowing into the water quality monitoring device 19 is a mixture of the stored water 17 from the condensate storage facility 15 and a part 9 of the return water from the condensate desalination device 6. . This is the plant make-up water supplied to the load 12 of the condensate make-up water system.
It has the same water quality as 16
Although it was consistent with the purpose of monitoring the water quality of the plant makeup water 16 in, the water quality of only the stored water 17 could not be monitored independently.

Further, during the normal operation of the nuclear power plant, the mixing ratio of the reconstituted stored water 17 and the part of the return water 9 which compose the plant makeup water 16 may fluctuate. The conductivity that is being applied changes instead of becoming constant, causing a problem that the indicated value causes hunting.

The cause of the hunting of the indicated value is the stored water 17 and a part 9 of the return water from the condensate demineralizer 6.
In general, there is a large difference of about one digit in the electric conductivity, and therefore the electric conductivity greatly changes depending on the mixing ratio, so that the indicated value may change.

The object of the present invention is to determine whether the stored water and the surplus water are sufficiently mixed and collectively monitored for water quality in the condensate storage facility, or whether the stored water is monitored independently for the measurement indication value. Another object of the present invention is to provide a condensate replenishing water device that does not cause hunting.

[0014]

In order to achieve the above object, a condensate replenishing water device according to the invention of claim 1 is a plant that combines the stored water of a condensate storage facility and the surplus water of a condensate desalination device. In a condensate make-up water device for supplying a load of control water as make-up water, a water supply pipe having a condensate transfer pump and a water quality monitoring device arranged in parallel is connected between the condensate storage facility and the load, and this water supply A connecting pipe having a check valve inserted from a condensate demineralizer is connected to the upstream side of the condensate transfer pump in the pipe, and a return water pipe is provided between the upstream side of the check valve and the condensate storage facility. It is characterized by connecting.

In the condensate make-up water device according to the second aspect of the present invention, the stored water of the condensate storage facility and the surplus water of the condensate demineralizer are supplied together to the control water load as plant make-up water. In the condensate replenishment water system, a condensate transfer pump and a water quality monitoring device are connected in parallel between the condensate storage facility and the load, and a water supply pipe is connected between the condensate storage facility and the load. A connecting pipe was connected from the condensate desalination device to the above, and a water quality monitoring pipe having a booster pump and a second water quality monitoring device was connected between the upstream side of the condensate transfer pump and the condensate storage facility. Is characterized by.

Further, in the condensate make-up water device according to the third aspect of the present invention, the stored water of the condensate storage facility and the surplus water of the condensate desalination device are combined and supplied to the control water load as plant make-up water. In the condensate replenishment water system, a condensate transfer pump and a water quality monitoring device are connected in parallel between the condensate storage facility and the load, and a water supply pipe is connected between the condensate storage facility and the load. A connecting pipe is connected to the condensate demineralizer, and a water quality monitoring pipe communicating with a drain is connected to the condensate storage facility via a second water quality monitoring device.

[0017]

According to the first aspect of the present invention, excess water of the condensate demineralizer is prevented from being mixed directly into the plant makeup water by the check valve, and once introduced into the condensate storage facility, the condensate is condensed. After being mixed and made uniform in the storage facility to make stored water, it is supplied to the load of control water as plant makeup water. For water quality measurement, a part of the plant makeup water whose water quality is made uniform in the condensate storage facility is introduced into the water quality monitoring device and continuously measured.

According to the second aspect of the present invention, the stored water in the condensate storage facility and the surplus water of the condensate demineralizer are mixed and supplied to the control water load as plant makeup water. In addition, in the water quality measurement, plant makeup water is continuously measured by a water quality monitoring device. Further, the stored water in the condensate storage facility is continuously measured by the second water quality monitoring device by operating the booster pump.

According to the third aspect of the present invention, the stored water in the condensate storage facility and the surplus water of the condensate demineralizer are mixed and supplied to the control water load as plant makeup water. For water quality measurement, the plant makeup water is continuously measured by a water quality monitoring device, and for the stored water, the second water quality is measured on the way from the condensate storage facility to the drain via the water quality monitoring pipe. Measure continuously with a monitoring device.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. It should be noted that the same components as those of the above-described conventional technique are designated by the same reference numerals and detailed description thereof will be omitted. In the main steam system in a nuclear power plant, as shown in FIG. 4, the main steam 2 generated in the reactor pressure vessel 1 is condensed in a condenser 4 into a condensed water 5 after driving a turbine 3. Thereafter, the condensate 5 is purified by the condensate demineralizer 6 and constitutes a closed loop which returns to the reactor pressure vessel 1 again.

The surplus in the condensate desalination unit 6 is branched from the outlet side of the condensate desalination unit 6 and discharged at a constant flow rate outside the main steam system, and is controlled as return water from the condensate desalination unit 6. As a water source of the rod drive water pump 7, a constant flow rate is supplied to the control rod drive system load 8. Also, part of the return water (dotted arrow)
9 is supplied as excess water to each load 12 of the condensate makeup water system.

In the first embodiment, as shown in the configuration diagram of FIG. 1, the condensate makeup water supply device 22 includes a condensate storage facility 15 into which purified treated water from the waste treatment system 21 is introduced, and the condensate storage device 15. A water supply pipe 14 having a condensate transfer pump 13 for supplying stored water 17 to each load 12 of the condensate makeup water system is connected to the water storage facility 15.

In addition, a closed loop of the water quality monitoring system is formed in the water supply pipe 14 and branches from a water sampling point 18 with the condensate transfer pump 13 interposed and returns to a return point 20 via a water quality monitoring device 19. . Further, from the condensate demineralizer 6, a return water pipe 24 is connected to the condensate storage facility 15 via a communication pipe 10 for introducing a part 9 of the return water, and is also connected to the upstream of the condensate transfer pump 13. A check valve 23 for blocking the inflow of a part 9 of the return water is connected between the connecting pipes 10.

Next, the operation of the above configuration will be described. Return water from the condensate demineralizer 6 is supplied to the control rod drive system load 8 by the control rod drive water pump 7, and a part of the return water 9 passes through the connecting pipe 10 and the return water pipe 24. The water quality is averaged by once flowing into the condensate storage facility 15, mixed internally and stored as the stored water 17.

The uniformed stored water 17 in the condensate storage facility 15 is supplied as plant make-up water 16 to the load 12 of the condensate make-up water system through the water supply pipe 14 by the operation of the condensate transfer pump 13. To be done. That is, a comparatively small amount of the return water 9 (for example, a flow rate of about 20 m ³ / h) is introduced into an extremely large-capacity condensate storage facility 15 (generally, a storage capacity of about 2000 m ³ ) and stored water 17 Since they are mixed, their electrical conductivity is made uniform, and the water quality fluctuations of the stored water 17 in the condensate storage facility 15 become extremely gentle.

Further, a part of the stored water 17 is guided from a water sampling point 18 downstream of the condensate transfer pump 13 to a water quality monitoring device 19 to measure the water quality, and returned to a water supply pipe from a return point 20. Regarding the water quality measured here, since the stored water 17 in the condensate storage facility 15 and the plant makeup water 16 have the same water quality,
Both can be collectively measured by the water quality monitoring device 19.

Regarding the change in conductivity which causes hunting of the indicated value when monitoring the water quality, a relatively small amount of a part of the return water 9 flows into the large amount of stored water 17 and is mixed. From this, since the water quality variation of the stored water 17 guided to the water quality monitoring device 19 is performed extremely gently, hunting does not occur in the indicated value which is the water quality measurement result.

In the second embodiment, as shown in the configuration diagram of FIG. 2, the general configuration of the condensate replenishing water device 25 is almost the same as the conventional one shown in FIG. Piping
A booster pump 26 and a water quality monitoring pipe 28, in which a second water quality monitoring device 27 is inserted, are connected between the connection point of the communication pipe 10 at 14 and the condensate transfer pump 13 side.

As a function of the above structure, a part 9 of the return water from the condensate demineralizer 6 flows into the water supply pipe 14 via the connecting pipe 10. The stored water 17 also flows down through the water supply pipe 14 and merges with the part 9 of the return water, and is supplied via the condensate transfer pump 13 as plant makeup water 16 to the load 12 of the condensate makeup water system.

The water quality of the plant makeup water 16 at this time is stirred and mixed by the condensate transfer pump 13 and then part of it is sent to the water quality monitoring device 19 for measurement. The water 17 passes through the water quality monitoring pipe 28 by the operation of the booster pump 26, and the conductivity is continuously measured and monitored by the second water quality monitoring device 27.

Moreover, the measured stored water 17 alone is pumped to the water supply pipe 14 by the booster pump 26 via the second water quality monitoring device 27, so that a part of the return water 9 and the plant. There is no contact with make-up water 16, and therefore the indicated value does not change and hunting does not occur.

In the third embodiment, as shown in the configuration diagram of FIG. 3, the general configuration of the condensate replenishing water device 29 is almost the same as the conventional one shown in FIG. A second water quality monitoring device 27 is inserted on the way, and a water quality monitoring pipe 28 whose tip reaches a drain 30 is connected.

As in the case of the second embodiment, part of the return water 9 and the stored water 17 are agitated and mixed by the condensate transfer pump 13 and the plant makeup water 16 is loaded into the condensate makeup water system. While being supplied to 12, a part of this is sent to the water quality monitoring device 19 to measure the water quality.

The stored water 17 in the condensate storage facility 15 is continuously supplied by the second water quality monitoring device 27 while flowing down from the condensate storage facility 15 through the water quality monitoring pipe 28 to the drain 30. Since the conductivity is measured and there is no communication with the communication pipe 10 and the water supply pipe 14, there is no contact with the part 9 of the return water and the plant makeup water 16, and therefore the second water quality monitoring device 27 Since the conductivity of the measured stored water 17 alone does not change, hunting does not occur in the indicated value.

[0035]

As described above, according to the present invention, in the condensate make-up water device for supplying the plant make-up water as control water to each load of the plant, the water quality of the stored water stored in the condensate storage facility is continuously monitored, Moreover, there is an effect that the indicated value can be easily measured without causing hunting.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a condensate makeup water supply device according to a first embodiment of the present invention.

FIG. 2 is a system configuration diagram of a condensate makeup water supply device according to a second embodiment of the present invention.

FIG. 3 is a system configuration diagram of a condensate makeup water supply device according to a third embodiment of the present invention.

FIG. 4 is a schematic system diagram of a condensate makeup water system of a conventional nuclear power plant.

FIG. 5 is a system configuration diagram of a conventional condensate makeup water supply device.

[Explanation of symbols]

1 ... Reactor pressure vessel, 2 ... Main steam, 3 ... Turbine, 4 ...
Condenser, 5 ... Condensate, 6 ... Condensate demineralizer, 7 ... Control rod drive water pump, 8 ... Control rod drive system load, 9 ... Part of return water (dotted arrow), 10 ... Communication pipe, 11, 22, 25, 29 ... Condensate make-up water device, 12 ... Condensate make-up water system load, 13 ... Condensate transfer pump, 14 ... Water supply pipe, 15 ... Condensate storage facility, 16 ... Plant make-up water (white arrow) ), 17 ... Stored water (solid arrow), 18 ... Water sampling point, 19 ... Water quality monitoring device, 20 ... Return point, 21 ... Waste treatment system, 23 ... Check valve, 24 ... Return water pipe, 26 ... Booster Pump, 27 ... Second water quality monitoring device, 28 ... Water quality monitoring pipe, 30 ...
Drain.

Claims (3)

[Claims] 1. A condensate replenishment water device for supplying stored water of a condensate water storage facility and surplus water of a condensate desalination device together as control water to a load of control water, wherein: A condensate transfer pump and a water quality monitoring device are connected in parallel between them to connect a water supply pipe, and a check valve is inserted from the condensate desalination device upstream of the condensate transfer pump in this water supply pipe. A condensate make-up water device, characterized in that a return water pipe is connected between the upstream side of the check valve and the condensate storage facility while connecting the pipe. 2. A condensate replenishment water device for supplying stored water of a condensate storage facility and surplus water of a condensate desalination device together to a load of control water as plant makeup water, wherein A condensate transfer pump and a water quality monitoring device are connected in parallel between them to connect a water supply pipe, and a connection pipe from a condensate desalination device is connected to the upstream side of the condensate transfer pump of this water supply pipe, and A condensate replenishing water device, characterized in that a booster pump and a water quality monitoring pipe having a second water quality monitoring device are connected between the upstream side of the condensate transfer pump and the condensate storage facility. 3. A condensate replenishment water device for supplying stored water of a condensate water storage device and surplus water of a condensate desalination device together as plant make-up water to a load of control water. A condensate transfer pump and a water quality monitoring device are connected in parallel between them to connect a water supply pipe, and a connection pipe from a condensate desalination device is connected to the upstream side of the condensate transfer pump of this water supply pipe, and A condensate replenishment water device characterized in that a water quality monitoring pipe communicating with a drain is connected to a condensate storage facility by inserting a second water quality monitoring device.