JPH0558131B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a leakage detection device for a condensate storage tank, and particularly to a leakage detection device for a condensate storage tank, and in particular, when the inner surface of a concrete container is lined with a metal plate to store condensate, The present invention relates to a leakage detection device for a condensate storage tank that can quickly detect leakage.

[Technical Background of the Invention] So-called lined storage tanks, which have containers made of concrete and lined with metal plates such as stainless steel or synthetic resin plates, are widely used in nuclear power-related facilities, general chemical plants, and the like.

Incidentally, condensate storage tanks in which the inner surface of a concrete container is lined with stainless steel have recently begun to be used as storage tanks for storing condensate in nuclear power generation facilities.

However, if cracks or pinholes occur in the welded parts of the stainless steel and condensate from the storage tank leaks, it will cause environmental pollution, so the leak needs to be detected promptly.

FIG. 3 shows an example of a conventional leakage detection device for a condensate storage tank, and reference numeral 1 in the figure diagrammatically indicates the condensate storage tank.

Although this condensate storage tank 1 is not shown, the inner surface of a concrete container is lined with a stainless steel plate.

Condensate 3 is stored in each condensate storage tank 1 . This condensate storage tank 1 has a rectangular parallelepiped shape, and although not shown, the bottom, side and ceiling surfaces are made of concrete, lined with stainless steel plates that press against the concrete walls, and the sides are filled with liquid. Piping such as an inlet pipe and a communication pipe are provided at the bottom, and an outlet pipe and a drain pipe are provided on the bottom of the concrete wall.

A plurality of leakage liquid sampling pipes 4 are connected to the bottom of the condensate storage tank 1 at approximately equal intervals, and a block area leak gate valve 5 is connected to each leakage liquid sampling pipe 4, respectively.

The downstream side of the plurality of leakage liquid sampling pipes 4 is connected to a communication pipe 6, and the downstream side of this communication pipe 6 is connected to a drain pot 8 via a sight glass 7. An overflow pipe 9 is led out from the upper side of the drain pot 8, and the downstream side of the overflow pipe 9 is connected to a sump tank 10.

A liquid level gauge 11 is connected to the side surface of the drain pot 8 via valves 12 and 13, and a drain pipe 14 is connected to the bottom surface of the drain pot 8, and this drain pipe 14 is connected to the overflow pipe 9.
via a valve 15, and also connected to the valve 13 of the liquid level gauge 11.

In the above device, if a leak occurs from the condensate storage tank 1, the leaked liquid is collected in the leaked liquid collection pipe 4, blocked by the block area leak gate valve 5, and sight glass 7.
It passes through and is guided to the drain pot 8.

Therefore, by monitoring the sight glass 7, leaking liquid from the condensate storage tank 1 can be detected. Furthermore, since the leaked liquid collected in the drain pot 8 can be constantly monitored by the liquid level gauge 11, a so-called double safety measure is taken.

The leaked water collected in the drain pot 8 in this way is transferred to the sump tank 10 before overflowing.
The water can be drained by opening the valve 15 connected to the water.

Fig. 4 shows another conventional example, and has almost the same structure as Fig. 3, except that the block area leak gate valve 5 is replaced with a sight glass 7, and the other features are the same as Fig. 3. The structure is similar, and the means for detecting leaked liquid is also the same as the apparatus shown in FIG.

[Problems with the Background Art] However, in the case of the example shown in Figure 3, the occurrence of a leak can be detected immediately, but in order to confirm which block in the storage tank the leak is coming from, it is necessary to It is necessary to open and close each block area leak gate valve 5 each time, and there is a drawback that quick response is extremely lacking.

In addition, in the example shown in FIG. 4, if the amount of leakage is extremely small, for example, about one drop per hour, it is extremely difficult for the operator to visually monitor the side glass 7. It has the disadvantage that detection is extremely difficult and may cause false confirmation.

[Object of the Invention] The present invention has been made to eliminate the above-mentioned drawbacks, and is capable of quickly detecting a slight leakage of liquid from a condensate storage tank, and also detecting from which part of the storage tank the liquid is leaking. can be reliably detected,
It is an object of the present invention to provide a leak detection device for a condensate storage tank that has a simple structure.

[Summary of the Invention] That is, the present invention includes a condensate storage tank having a lining on the inner surface of the container, and a plurality of leakage liquid collection pipes arranged around the storage tank to collect leakage liquid leaking from the lining. , a plurality of receivers are arranged at the downstream openings of these leakage liquid collection pipes, and a plurality of receivers are arranged in each of these receivers, satisfying the conditions that the liquid level is above the specified value and the electrical conductivity is below the specified value. A conductivity meter and a liquid level gauge equipped with an alarm to issue an alarm, a drain pipe for discharging the leaked liquid that has fallen into each of the above-mentioned receiving trays, a drain pot provided on the downstream side of this drain pipe, and a drain pot installed in this drain pot. A leakage detection device for a condensate storage tank consisting of a power meter with an alarm and a liquid level meter that issues an alarm when the liquid level is above a specified value and the conductivity is below a specified value. It is.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a system diagram showing one embodiment of the present invention, and FIG. 2 is a longitudinal cross-sectional view partially enlarging the bottom of the storage tank in FIG. 1. Code 1 in Figure 1
indicates a condensate storage tank. This condensate storage tank 1
The bottom, side and ceiling surfaces of the container constituting the main body of the tank are made of concrete, and the stainless steel lining plate lining this concrete surface is exposed to the wall surface in advance when the outer concrete wall of the condensate storage tank 1 is cast. In the base material embedded like this,
It is attached and fixed by welding after the concrete hardens.

The lining plate is usually a thin stainless steel plate with a thickness of 3 to 6 mm, and is pressed against the concrete side surface by the pressure of the condensate 3 in the condensate storage tank 1.

Piping such as an inflow pipe and a communication pipe for the condensate 3 (not shown) are provided on the wall of the ascites storage tank 1, and an outlet pipe and a drain pipe are provided on the bottom thereof penetrating the concrete wall.

FIG. 2 shows the bottom of such a condensate storage tank 1, and in the figure, reference numeral 20 indicates a base material provided at the bottom 21 of the concrete container. The upper surface of the bottom base material 20 is covered with a lining plate 19 made of stainless steel, for example. Also,
Since the condensate 3 is slightly radioactive, a plurality of leakage liquid collection pipes 4 are buried in the flooring material 20 in order to detect the leakage of the condensate 3 more strictly. A leak detection groove 23 is provided to guide the collection tube 4 . Note that the reference numeral 22 indicates an embedded channel.

Therefore, if there is leakage from the welded part of the lining plate 19, the leaked liquid will be transferred to the embedded channel 22.
It passes through the leakage detection groove 23 provided in the upper flooring material 20, flows into the leakage liquid collection pipe 4 connected to the leakage detection groove 23, and enters the downstream opening of the leakage liquid collection pipe 4 as shown in FIG. It falls into the provided tray 24.

In FIG. 1, the tray 24 is provided with a conductivity meter 26 for measuring the conductivity of the falling leaked liquid and a liquid level gauge 28 for measuring the level of the leaked liquid. The liquid level gauge 28 is connected to the alarm 27 via a converter 29.

Further, on the side of each saucer 24, there is a saucer 24.
Drain piping 3 for discharging leaked liquid that has fallen into
4 is connected. Each drain pipe 34 is connected to a communication pipe 6, and the downstream side of the communication pipe 6 passes through the lid 33 of the drain pot 8.
It is open to Conductivity meter 3 in drain pot 8
7 and a liquid level gauge 36 are provided, and a conductivity meter 37 is provided.
The liquid level gauge 36 is connected to an alarm 39 via a converter 38.

Further, an overflow pipe 9 is connected to the upper side surface of the drain pot 8, and the downstream side of this overflow pipe 9 is connected to a sump tank 10.

Furthermore, an outlet pipe 40 is inserted from the bottom of the drain pot 8.
A valve 15 is inserted downstream of the outlet pipe 40 and connected to the side surface of the overflow pipe 9.

Next, the operation will be explained.

In the leakage detection device for the condensate storage tank 1 configured as described above, when a crack occurs in the lining plate 19 of the condensate storage tank 1 and leakage occurs, the leaked liquid falls into the leakage detection groove 23. The collected leaked liquid passes through the collection tube 4 and falls into the receiving tray 24.

Only when two conditions are met: the leaked liquid falls into the saucer 24 and accumulates in excess of a specified amount and the liquid level gauge 28 is activated, and the conductivity meter 26 indicates a conductivity below the specified value. converter 2
An alarm device 27 issues an alarm via 9.

Therefore, by checking which alarm device 27 has issued the alarm, it is possible to know with certainty from which position in the condensate storage tank 1 the leak is occurring.

This alarm 27 becomes the first leak detection location.

Next, the leaked liquid that has accumulated in the tray 24 in excess of a specified amount flows into the drain pot 8 through the drain pipe 34 located on the side. And this drain pot 8
Although not shown, leakage liquid from other blocks or other condensate storage tanks is also concentrated and collected, and when the leakage liquid accumulates to a certain level, the liquid level gauge 36 is activated, and the electrical conductivity When the electrical conductivity is shown to be less than the specified value by the meter 37, the converter 3
An alarm device 39 issues an alarm via 8.

Therefore, this alarm 39 becomes a second leak detection location, and even if a leak is missed by the alarm 27, it can be detected here. In the state where the alarm is issued, a portion of the water overflows from the overflow pipe 9, and the state of the leaked water in the drain pot 8 and the state of the saucer 24 is confirmed, and the valve 15 is opened to remove the leaked water. passes through the outlet pipe 40 and the overflow pipe 9
The water is drained to the sump tank 10 through the

[Effects of the Invention] As explained above, according to the present invention, at the first leak detection location, a liquid level meter and a conductivity meter are installed for each leak detection section, and are connected to an alarm. Therefore, it is easy to see which block the leak is coming from.

Furthermore, if the leaked liquid is from a source other than the condensate storage tank, for example, from a building frame, the electrical conductivity will be higher than that of the condensate because it contains many impurities. Therefore, since the conductivity meter does not react, malfunctions due to pseudo leakage can be prevented. Furthermore, even if a leak is missed at the first leak detection location, the second
Since leaks can be detected at the same leak detection location, a double safety measure is taken, and reliability is greatly improved.

Note that the present invention is not limited to the above embodiments, and is not limited to the shape or number of storage tanks.

In addition, a liquid level gauge installed in the saucer or drain pot,
Generally used conductivity meters, converters, and alarms can be used.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an embodiment of a leakage detection device for a condensate storage tank according to the present invention, and FIG. 2 is a vertical sectional view showing an enlarged bottom of the condensate storage tank in FIG. 1.
FIGS. 3 and 4 are system diagrams showing conventional leakage detection devices for condensate storage tanks, respectively. 1... Condensate storage tank, 4... Leakage liquid collection pipe, 8...
...Drain pot, 24...Saucer, 26, 37...
...Conductivity meter, 27,39...Alarm device, 28,36
...Liquid level gauge, 34...Drain piping.

Claims (1)

[Claims] 1 A condensate storage tank having a lining on the inner surface of the container, a plurality of leakage liquid collection pipes arranged around this storage tank to collect leakage liquid leaking from the lining, and the downstream side of these leakage liquid collection pipes. A plurality of trays each placed in each opening, and an alarm device placed in each tray that issues an alarm when the condition that the liquid level is above a specified value and the conductivity is below a specified value is provided. A conductivity meter and a liquid level meter,
A drain pipe for discharging the leaked liquid that has fallen into each of the above-mentioned receiving trays, a drain pot provided on the downstream side of this drain pipe, and a drain pot disposed in this drain pot whose liquid level is above a specified value and whose conductivity is below the specified value. A leak detection device for a condensate storage tank consisting of a conductivity meter and a liquid level gauge with an alarm that issues an alarm when certain conditions are met.