JPS63303293A - Piping universal joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a piping universal joint installed in a piping system distributing liquid metal such as a fast breeder reactor power plant, and in particular, This invention relates to a pipe universal joint that safely absorbs mutual radial displacement of pipes.

(Prior technology) Fast breeder reactor (F[3R) power generation plans 1~ use ζmetal sl-lium, which is melted at high temperatures, as a coolant, and the liquid metal sl-lium is used in the piping system. The steam is circulated through an internal heat exchanger to generate steam that drives a turbine generator.

In conventional fast breeder reactor power plants (JuruP1), as a measure to alleviate the stress exerted on the piping system due to displacement due to thermal expansion of the helium piping system and relative displacement that occurs between each piece of equipment during an earthquake, it is necessary to A method is adopted in which bent pipe sections are formed or expansion joints are installed.In other words, a method is adopted in which a large number of bent pipe sections are formed within the piping system, or the pipes are configured vertically and horizontally, or By inserting a bellows joint formed into a bellows shape into the thulium pipe system, thermal expansion a3.J and displacement that occurs during an earthquake can be absorbed in each curved pipe section and the bellows joint. , the bending stress that occurs is suppressed within allowable values.

(Problems that the invention is trying to solve) However, the conventional curved pipe section (J method) has a simple structure and can reliably absorb displacement;
There are disadvantages in that the length of the sodium piping becomes extremely long, the space for laying the piping increases, the space utilization efficiency and operating cost f1 of the plant decreases, and the construction cost increases.

In other words, the sodium piping must be heated at all times to a temperature above its melting point to prevent the flowing metal (1) from solidifying.
-3 and 1~ Since a bending neck is required for the detector, etc. that detects the leakage of lium with high sensitivity, the construction and operating costs per unit length of piping are lower than those for light water reactors. Compare No. 1
There is always the problem that 4T is expensive.

- On the other hand, consideration is being given to reducing the overall length of sodium piping as much as possible by using bellows joints as stoppers, thereby reducing the construction cost of plant equipment.

When this bead joint is used, it has an excellent ability to absorb relatively small static displacements in the axial direction caused by thermal expansion of piping, etc. However, it is difficult to absorb the large-scale dynamic displacement that occurs in the event of an earthquake and the displacement that occurs in the radial direction of the pipe. Bellows fittings are characterized by their durability,
It has not been widely adopted because its safety and operational reliability are relatively low (R = 1). Therefore, at present, this method cannot be used as a means to drastically shorten the piping system.

The present invention has been made in order to solve the above problems, and has a simple structure, and while keeping the flowing liquid metal liquid-tight, it is possible to prevent large displacement in the radial direction from being applied to the piping connection part. The purpose is to provide a piping universal joint that can absorb

[Structure of the invention]

(Means for Solving the Problem) The piping universal joint according to the present invention includes an outer peripheral flange formed at the connecting end of a pipe through which liquid metal flows, and a plurality of cooling plates arranged between the opposing outer peripheral flanges with spacers. The cooling plates are arranged in multiple layers at predetermined intervals, and the temperature of each cooling plate is set to below the freezing point of the liquid metal by tightening the outer peripheral flanges to each other. J is characterized by solidifying the liquid metal that has flowed between the cooling plates to liquid-tightly seal the space between the cooling plates.

(Function) According to the piping universal joint having the above configuration, the plurality of cold FJI plates are arranged between the outer peripheral flanges and are arranged in multiple layers at predetermined intervals via spacers. A portion of the flowing liquid metal flows into the gap between adjacent cooling plates. The temperature of each cooling plate is set below the freezing point of the liquid metal, and the liquid metal flowing into the gap is cooled and solidified. The solidified metal effectively seals the gap "liquidtight", thereby preventing the liquid metal flowing within the universal joint from leaking to the outside.

On the other hand, when adjacent pipes are significantly displaced in the radial direction due to thermal expansion of the pipes or an earthquake, the multiple cooling plates interposed between the outer flanges absorb each other's displacements little by little, and the joint as a whole maintains a predetermined position. = 4 − displacement between can be safely absorbed.

In other words, the displacement that occurs in the entire joint is dispersed into minute displacements that occur on each cooling plate, so the solidified metal is less likely to be broken due to displacement between adjacent cooling plates, and good sealing performance is maintained. be done.

On the other hand, even when solidified metal is broken, the liquid metal that newly flows into the broken surface instantly solidifies.
There is no leakage of liquid metal.

Therefore, even if a large displacement occurs in the radial direction of adjacent piping, the displacement is easily absorbed without any leakage of liquid metal, so there is less chance of excessive stress acting on the displaced portion of the piping. .

(Example) Next, an example of the present invention will be described with reference to the accompanying drawings.

The piping universal joint shown in FIG. 1 has outer peripheral flanges 3a, 3b at the connecting ends of piping 2a, 2b through which liquid metal 1 flows. Opposing outer peripheral flanges 3a.

A plurality of cooling plates 4 are provided between l'li! will be established. The cooling plates 4 are formed into a hollow disk shape having an opening larger than the inner diameter of the piping, and are arranged in multiple layers at predetermined intervals with spacers 5 interposed between them. Spae 1 no 5 is cold 7, IIIfi
/I has the same name on the surface of the IC sliding plate 6, and the sliding plate 6 is in close contact with the transfer white stone, and the EJ is installed on the surface of the opposing cold JJl plate 4.
The roller 7 is made up of Opposing loose piping 2a,
The outer peripheral flanges 3a and 3b formed at the ends of the cold 2JJ plates 1 and 2b are tightly fastened to the cold 2JJ plates 1 and 2b by a joining member 8, and each cold uI plate 4 is held in a fixed position. In addition, the piping 2a excluding the outer peripheral flanges 3a, 3b and the cooling plate 4 portion
, 2b is fitted with a heat insulator 9, and the temperature of each cooling plate 4 is set to be below the freezing point of the liquid metal 1.

As for the material of the cooling plate 4, a material having varying thermal conductivity, such as copper, is generally used. In addition, the specifications of the cooling plate 4, such as the inner diameter D, outer diameter D1, number n of J scoops disposed, and interval d, are as follows.
Operating temperature of liquid metal 1-lium, Plan 1 - Determined by surrounding outside air, distribution, maximum displacement absorption 3 Snow, 1
The temperature distribution in the radial direction in the gap of each cold 7JI plate 4 is as follows:
5 so that the temperature decreases from the center to the periphery.
9.

That is, as shown in FIG. 2, the temperature drops below the freezing point (approximately 97°C in the case of metallic sodium) at the intermediate portion between the outer diameter D and the inner diameter D2 of the cooling plate 4, and the inner diameter D of the solid metal layer 10 decreases.
The position of 3 is set so as to satisfy the relationship of equation (1) below.

D2<D3<Dl (1) According to the piping universal joint of this embodiment, sodium, which is a liquid metal, flowing in the piping 2 flows into the gap between the adjacent cooling plates 4. The flowing liquid sodium is cooled down to below its freezing point by the cooling plate 4, solidifies in the middle of the gap, and forms a solid metal layer 10. The solid metal layer 10 effectively seals the gap and prevents the metallic sodium flowing through the pipe 2 from leaking to the outside.

Next, the effect when a large displacement X occurs in the piping section due to thermal expansion of the piping 2 or an earthquake will be described with reference to FIG.

The displacement x caused between the opposing pipes 2a and 2b is absorbed by each cooling plate 4 arranged in a stacked manner.

At this time, the displacement position Δ is absorbed by each adjacent cooling plate 4.
X is determined by equation (2), where n is the number of cooling plates 4 disposed.

ΔX=-1 (2) Since the length ΔX of displacement of each adjacent cooling plate 4 is minute, it will solidify in close contact with that cooling plate 4! Solid metal layer 10
Although it is unlikely that the cooling plates 4 will be broken, the sealing properties between the cooling plates 4 will be maintained.

If the piping universal joint of this embodiment is J:, it is possible to prevent the leakage prevention function of the liquid metal 1, such as liquid metal 1 flowing through the piping 2, by one person in the radial direction of the piping 2. Since large displacements can be safely absorbed, excessive stress is less likely to be applied to the displaced parts.

In addition, the piping universal joint of this embodiment has a simpler structure than the conventional method of forming a bent pipe part or a bellows joint, and it is possible to shorten the total piping length for liquid metal.
As a result, the construction costs and operating costs for Fast Breeder Reactor Lightning Generation Plan 1 can be significantly reduced.

In the embodiment shown in FIG. 1, the spacer 5 is composed of a sliding plate 6 and a roller 7 arranged at a predetermined interval on the circumference of the cooling plate 4. It may be composed of In this case, leakage of the liquid metal flowing into the gap portion of the cooling plate 4 can be more effectively prevented.

〔Effect of the invention〕

As explained above, according to the piping universal joint according to the present invention,
A plurality of cooling plates are arranged between the outer peripheral flanges, each with a spacer interposed therebetween, and the flood point of each cooling plate is
Since the temperature is set below the freezing point of the liquid metal, the liquid metal flowing into the gap between the cooling plates is cooled and solidified, effectively stopping the gap. Therefore, the distribution lead inside the universal joint is
This prevents the liquid metal from leaking to the outside.

In addition, even if adjacent pipes are displaced in the radial direction due to thermal expansion of the pipes or an earthquake, each cooling plate inserted between the outer flanges absorbs the displacement little by little, and the joint as a whole absorbs the specified amount of displacement. Absorb safely. therefore,
Excessive stress is less likely to act on the displaced portion of the piping.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing one embodiment of the piping universal joint according to the present invention, Fig. 2 is a cross-sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 shows the state when the piping is displaced. FIG. 1...Liquid metal, 2.2a, 2b...Piping, 3゜3
a, 3b...Outer periphery flange, 4...Cooling plate, 5...
・Spacer, 6...Sliding plate, 7...Roller, 8...
- Joining member, 9... heat insulating material, 10... solid metal layer. Representative Patent Attorney Nori Chika Ken Tama Komaru Ken Figure 1

Claims (1)

[Claims] 1. An outer peripheral flange is formed at the connecting end of a pipe through which liquid metal flows, and a plurality of cooling plates are disposed in multiple layers at predetermined intervals between the opposing outer peripheral flanges via spacers. ,
The cooling plates are held by tightening the outer flanges to each other, and by setting the temperature of each cooling plate below the freezing point of the liquid metal, the liquid metal that has flowed between the cooling plates is solidified, and the temperature between the cooling plates is A piping universal joint characterized by being liquid-tightly sealed. 2. The piping universal joint according to claim 1, wherein the spacer is constituted by an annular seal ring.