JPH025188Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a method for safely dealing with leakage of liquid metal, etc. by making it possible to identify in advance the points where liquid leaks from liquid metal piping and other piping to the outside. This relates to a piping protection device that can protect the piping.

[Prior Art] Generally, in nuclear reactors and other high-temperature power engines, liquid metals (eg, sodium) that are liquid up to high temperatures are used as coolants. For example, in a heat exchanger as a steam generation device for a fast breeder reactor, liquid metal (sodium) at around 500°C is used as a medium for steam generation, and is led to the heat exchanger through liquid metal piping. Liquid metal burns when it comes into contact with water, steam, etc. and reacts with it. Therefore, as a safety measure, the liquid metal is stored in pipes, heat exchangers, etc., and protected with a protection device (or heat retention device) so that it is sealed from the outside air, and consideration is given to preventing leakage of the liquid metal.

An example of a conventional piping protection device is shown in FIG. 1, in which an annular tube b is arranged outside a liquid metal piping a to form a sealed space c around the outer periphery of the piping a, and an annular tube b is arranged outside the liquid metal piping a. A structure in which a heat insulating material d is arranged in a layered manner on the outside of the heat insulating material d and the space c forms a heat insulating structure, and an exterior material e is further arranged outside the heat insulating material d, or a structure made of liquid metal. In cases where the temperature is low, there is a structure in which the heat insulating material d and the exterior material e are abolished, and the annular tube b is airtightly fixed and protected only by the sealed space c. .

In any of the above configurations, the liquid metal pipe a is very long, and when the pipe a is damaged for some reason, it is necessary to detect that the liquid metal inside the pipe has leaked into the space c. A detector (not shown) is installed. As a detector, a liquid metal leak detector such as a gas sampling method or a contact type sodium leak detector is used, and if the liquid metal pipe a is damaged and the liquid metal inside the pipe leaks, the pipe a is damaged. It is designed to detect liquid metal leaks regardless of where they are.

[Problem to be solved by the invention] However, when the liquid metal pipe a is damaged and the liquid metal inside the pipe leaks into the space c, the pressure in the space c becomes
It's getting higher because of the leaking liquid metal. Annular tube b is made strong enough to withstand up to a certain level of pressure; however, if the pressure is increased above a certain level due to leakage of liquid metal, there is a possibility that annular tube b will be damaged. Leakage of the liquid metal inside the pipe due to breakage of the liquid metal pipe a can be detected by the detector described above, but if the liquid metal pipe a is a fast breeder reactor pipe, the pipe is very long and its protection device is necessary. The annular tube is also long. Therefore, Annular tube b
In the event of damage and leakage to the outside, the conventional annular tube B does not have any parts that are particularly prone to breakage, and all parts are equally strong enough to withstand up to a certain pressure. Because of this, it is not known which part of the annular tube b is damaged, so it is currently impossible to predict where leakage will occur outside the annular tube. Therefore, there is a problem in that it is difficult to take measures against leakage.

In the present invention, a specific part of the annular tube is made to be easily damaged in advance, and when the piping is damaged, the contents such as liquid metal inside the tube leak into the space inside the annular tube, and the pressure in the space is increased. When the temperature rises, the parts of the annular tube that are likely to be damaged are the first to break, so that when the annular tube is damaged and the contents leak to the outside, the location where the contents leak to the outside can be easily predicted, The aim is to make it easier to take measures against leaks.

[Means for Solving the Problems] In order to achieve the above object, the present invention arranges an annular tube outside the piping to form a sealed space between the piping and the annular tube, and the annular tube In a piping protection device in which a heat insulating material is arranged on the outside of the pipe, an opening is provided at a predetermined location of the above-mentioned annular pipe,
An opening/closing device that covers the entire surface of the opening from the outside of the annular tube is provided, and an elastic body is provided that constantly presses the opening/closing device against the annular tube with a force smaller than the force required to break the annular tube.

[Function] With the above configuration, when the pipe is damaged for some reason and the contents inside the pipe leak into the closed space, the pressure inside the closed space increases. There is a switching device at a predetermined location of the annular tube, and when the opening/closing device is closed, the above-mentioned sealed space is formed inside the annular tube, but before the annular tube breaks due to the above pressure increase. Then, the opening/closing device automatically opens to allow the leaked contents to flow out of the annular tube. This allows the location of leakage from the annular tube to be identified.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 2 shows an embodiment of the present invention, in which annular tubes 2 are airtightly disposed at appropriate intervals on the outside of the liquid metal piping 1 using piping clamps 6, and the lower surface of the annular tubes 2 is Insulating material 3 is always kept in one place in the
or by the action of an elastic body such as a spring (not shown) to keep the space 4 airtight, and due to the pressure increase in the space 4, the elasticity of the heat insulating material 3 or the spring The switchgear 5 is equipped with a switchgear 5 that can be pushed open by overcoming the enemy, and when the liquid metal pipe 1 is damaged and the liquid metal inside the pipe leaks into the space 4 and the pressure inside the space 4 increases, the switchgear 5 It opens to release the pressure and at the same time allows the leaked liquid metal to flow out from the opening/closing device 5. 7 is a fixing bolt.

In the present invention, a sealed space 4 is formed by the annular tube 2 outside the liquid metal pipe 1, so that the liquid inside the pipe 1 does not react with outside water or air. When the pipe 1 is damaged for some reason and the liquid metal inside the pipe leaks, the pressure within the space 4 increases, and internal pressure acts on the annular pipe 2. A switching device 5 is provided at a predetermined location of the annular tube 2 in order to release the pressure and protect the annular tube 2. Therefore, when the pressure in the space 4 exceeds a certain value, the switching device 5 closes at two points. It opens the earliest, as shown by the chain line. This prevents the annular tube 2 from being damaged at unspecified locations and protects the annular tube 2 itself, and the liquid metal leaking into the space 4 is transferred from the opened switchgear 5 to the outside of the annular tube 2. leak to. Therefore, the location of leakage to the outside can be identified.

The liquid metal leaked from the annular tube 2 to the outside,
Since it burns when it reacts with water, etc., it is necessary to treat it so that it does not react with water.

Figure 3 shows an example of safety measures to prevent the liquid metal leaking from the annular tube 2 from reacting with water, etc., and when the opening/closing device 5 is opened, a The piping 8 for flowing leaking liquid metal is placed in an open position, and the piping 8 is opened.
For example, while connecting to the liquid metal separation tank 9, a valve 10 is provided in the middle of the piping 8, and a pressure detector 11 is provided to detect the pressure in the space 4, and a detection signal from the pressure detector 11 is provided. can be input to the calculation device 12, and the calculation device 12 compares the signal from the pressure detector 11 with the set pressure signal 13, and when the pressure detected by the pressure detector 11 is higher, the valve 10 A command was issued to open the file.

In this embodiment, when the pipe 1 is damaged and the liquid metal inside the pipe leaks into the space 4, the pressure within the space 4 increases. The pressure in this space 4 is detected by a pressure detector 11, and when the pressure in the space 4 exceeds a predetermined value, the valve 10 is opened by a command from the calculation device 12, and the opening/closing device 5 is opened. do. As a result, the liquid metal leaking out of the annular pipe 2 is guided to the separation tank 9 via the pipe 8 and is safely disposed of.

It should be noted that the present invention is not limited to the above-described embodiment, and that the separation tank 9 may not be provided in FIG. 3, and that various other changes may be made without departing from the gist of the present invention. Of course, etc.

[Effects of the invention] As described above, according to the piping protection device of the present invention, an annular tube is disposed outside the piping to form a sealed space between the piping and the annular tube, and the annular tube is In a piping protection device in which a heat insulating material is arranged on the outside of the annular tube, an opening is provided at a predetermined location of the annular tube, a switching device is provided in the opening to cover the entire surface of the opening from the outside of the annular tube, and the opening and closing device is Since we have provided an elastic body that presses against the annular tube with a predetermined force that is smaller than the force required to break the annular tube, it is possible to identify the opening formation position where contents such as liquid metal in the piping leak from the protective device to the outside. In addition, by opening the opening by pushing the opening/closing device against the pressing force of the elastic body, it is possible to prevent the liquid metal from opening explosively and scattering the liquid metal when it leaks. Furthermore, when the pressure of the liquid metal decreases, the opening/closing device closes the opening using the pressing force of the elastic body, thereby minimizing the amount of leaking liquid metal. It is possible to take sufficient precautions against leaks such as, etc., and it is also possible to protect the annular tube itself since it is possible to avoid a situation where it is unknown where the annular tube installed outside the piping will be ruptured due to pressure. This can produce excellent effects.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of a conventional pipe protection device, Fig. 2 is a sectional view showing an outline of an implementation of the pipe protection device of the present invention, and Fig. 3 is a diagram showing another embodiment of the present invention. be. 1...liquid metal piping, 2...annular tube, 4...
...Space, 5... Switchgear, 8... Piping, 11...
pressure detector.

Claims (1)

[Scope of utility model registration request] In a piping protection device in which an annular tube is placed outside the piping to form a sealed space between the piping and the annular tube, and a heat insulating material is placed outside the annular tube, An opening is provided, an opening and closing device is provided that covers the entire surface of the opening from the outside of the annular tube, and an elastic body is provided that constantly presses the opening and closing device against the annular tube with a force smaller than the force required to break the annular tube. Features a piping protection device.