JPS6015841B2 - Heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger, and more particularly to a heat exchanger in which the inside of the heat exchanger tubes can be drained and the heat exchanger tubes can be easily maintained and inspected.

Figure 1 shows an example of a conventional steam generator applied to a sodium-cooled fast breeder reactor, which generates steam by utilizing the heat of a liquid metal, such as sodium, that is circulated as a coolant in a nuclear reactor. Shown below.

The liquid sodium heating steam generator shown in this figure has an upright closed container 1, into which water is supplied from the lower part and steam is taken out from the upper part. This closed storage container 1 consists of a cylindrical body 2, and has mirror plates 3 and 4 at its upper and lower ends. Inside the storage container 1, a cylindrical external shroud 5 with open ends is arranged concentrically with the body 2. An annular spatial region 25 is formed between the fuselage 2 and the outer shroud 5. The internal shroud 6 with both ends open is
It is arranged concentrically within the outer shroud 5. An annular spatial region 26 is formed between the inner shrawado 6 and the outer shrawado 5. The upper end portion of the outer shroud 5 is surrounded by a container 7 with an open top. The cylindrical portion 29 of the container 7 is the body 2
and spaced apart from the outer shroud 5 by a fixed distance. The lower end of the cylindrical part 29 of the container 7 is joined to the outer shroud 5. The east side of the spirally wound heat exchanger tube 24 is arranged within the annular space region D26.

A plurality of water supply headers 2 are arranged outside and at the bottom of the storage container 1, and the water supply header 20 has a water supply pipe 2 extending downward.
Connected to 1. The inlet connecting pipe 18 extends upward from the water supply header 20 toward the lower entry end of the yellowing pipe 24 . The upper side of each of the water supply pipes 20 is also formed with a flat tube sheet 19, which tube sheet 19 is connected to the lower end of the inlet connecting pipe 18. These inlet communication pipes 18 are connected to the inlet cylinder 11
and into the storage container 1 through the flat sleeve plate 12. Each sleeve plate 12 closes the upper end of a plurality of inlet sills 11 fixed to the end plate 4. The inlet cylinder 11 has a structure in which the lower part is open and the upper part extends into the storage container 1, and the inner diameter of the inlet cylinder 11 is larger than the outer diameter of the water supply header 20. The inlet cylinder 11, the water chamber 20, and the inlet communication pipe 18 are arranged so as to be located in a downwardly protruding portion of a virtual housing cylinder that surrounds all the heat exchanger tubes 24 in the external shroud 5 and is open at the bottom. has been done. 6 The upper outlet end of the poison heat pipe 24 is connected to the end plate 3 on the upper part of the storage container 1 by means of the outlet connecting pipe 17.
It extends upwardly into a bottom-open outlet cylinder 13 mounted on the steam header 15 and is connected to a tube sheet 14 at the bottom of the steam header 15 . A steam pipe 16 is connected to the top of each steam header 15, which is surrounded by a portion where the tube plate 14 and the wall of the outlet cylinder 13 converge. A sodium inlet pipe 10 passes through the body 2 into the space between the cylindrical part 29 of the container 7 and the outer shroud 5.

A sodium outlet pipe 9 is attached to the lower part of the body 2. Also, at the bottom of the storage container 1, there is a sodium discharge pipe 27.
is provided. During operation of the steam generator, hot sodium is conducted into the storage vessel 1 through the sodium inlet pipe 10 and from the annular region between the cylindrical part 29 of the vessel 7 and the outer shroud 5 to the upper part of the outer shroud 5. It flows. After inversion at the top, the sodium descends along the outside of the heat transfer tube 24 in the annular space area 26 while heating the water within the heat transfer tube 24. This sodium flows out of the storage container 1 through the sodium outlet pipe 9. On the other hand, water is supplied from water supply pipe 2
From 1, 2 rivers are led to the water supply header.

After that, the water passes through the inlet connecting pipe 18 from the water supply pipe 20, rises inside the spirally wound cinnabar tube 24, and goes up into the heat exchanger tube 2.
It receives heat from the high-temperature sodium flowing outside the tube 4, becomes steam, passes through the outlet connecting pipe 17, and flows out from the steam header 15 through the steam pipe 16. In storage container 1, the dotted line NI
A sodium liquid level is formed as shown by and N2.

Argon, which is an immutable gas, is filled above the liquid levels N1 and N2. In this steam generator, the crab in the storage container 1 is cut in the circumferential direction at the level shown by the dashed-dotted line LI, and each inlet cylinder 11 is cut in the circumferential direction at the level shown by the dashed-dotted line L2. After cutting the pipe 21 and the steam pipe 16, the east end of the heat transfer tube 24 can be pulled out of the storage container 1 for maintenance, inspection or disposal.

After that, as shown in FIG. 2, the upper end plate 3 with the steam header 15, the outlet connecting pipe 17, the east of the waste heat pipe 24, the internal shroud 6, the inlet connecting pipe 18, and the upper cut portion of the inlet cylinder 11 are removed. The assembly 28 consisting of the sleeve plate 12 and the water supply pipe 20 can be pulled upward from inside the body 2. When the maintenance and inspection of the corpse heat pipe 24 is completed, the assembly 28 is lowered back to the original location, and then the storage container 1 and the inlet cylinder 11 are butt welded along the cutting line, and the water supply pipe 21 and the steam pipe are 16 can be reconnected to restore the steam generator to its original condition. In this structure, the dashed-dotted lines L1, L
Although the assembly 28 can be pulled out by cutting the container 1 and the inlet cylinder 11 at a level as shown at 2, it has the following disadvantages.

In the above-described steam generator, since a plurality of inlet cylinders 11 are arranged on the lower head plate 4, it is necessary to have a large pitch between the centers of the inlet cylinders 11. In addition, in order to pull out the assembly 28 from the outer shroud 5, it is necessary to arrange the inlet cylinder 1 in a virtual cylinder with the lower part of the outer shroud 5 protruding, and therefore it is necessary to make the inner diameter of the outer shroud 5 larger than necessary. Along with this, not only the outer diameter of the internal shroud 6 becomes larger, but also the outer diameter of the body 2 has to be increased. Therefore, the volume of the storage container 1 increases, and a large space is required for its arrangement. In addition, the volume of the storage container 1 increases, and the amount of sodium retained increases. SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to provide a compact heat exchanger in which draining inside the refractory tubes and maintenance and inspection are easy. A feature of the present invention is that a cylindrical body whose upper end is sealed and whose lower end is open to the outside of the fuselage is provided by penetrating the mirror plate at the lower end of the fuselage and protruding into the fuselage,
The upper ends of the plurality of ring heat pipes arranged inside the fuselage and extending in the vertical direction pass through the end plate at the upper end of the fuselage and reach the outside of the fuselage, and the lower ends of the public heat pipes penetrate the side walls of the joints and reach the inside of the cylindrical body. The purpose is to attach to the lower end of the heat exchanger tube a lower header which passes through the body and reaches outside the body, is placed outside the body, and has a size that allows it to pass through the cylindrical body.

A preferred embodiment of the present invention will be described below with reference to FIG. The steam generator 31 includes a body 32, an upper end plate 33, a lower end plate 34, an internal shroud 35, an upper header 36, a lower header 37, a heat transfer tube 38, a water supply header 39, a steam header 40, and a sodium Inlet pipe 41, sodium outlet pipe 42
and a discharge pipe 43. At the upper and lower parts of the body 32, there are dome-shaped upper and lower end plates 33 and 34, respectively.

At the center of the upper mirror plate 33, an upper bulge 36 consisting of a cylindrical portion 44 and a dome-shaped mirror slope portion 45 is provided so as to protrude outwardly from the body 32. Further, a lower header 37 consisting of a cylindrical portion 46 and a dome-shaped mirror slope portion 47 is disposed at the center of the lower header plate 34 so as to protrude inwardly with respect to the body 32. The water supply side of the heat transfer tube 38 is attached to the water supply side, and the lower tube 37 forms a mirror field inside and outside the fuselage on this water supply side. fuselage 32
Inside, an internal shroud 35, identical to the fuselage 32, is arranged at approximately mid-level. At the top of the fuselage 32,
A sodium inlet pipe 41 is mounted at a position slightly lower than the upper end of the inner shroud 35, and a discharge pipe 43 is mounted at a position slightly higher than the upper end of the inner shroud 35. A sodium outlet pipe 42 is attached to the lower part of the body 32. A large number of spirally wound heat transfer tubes 38 are regularly arranged around the inner shroud 35 .

The upper end of each heat exchanger tube 38 is led upward into the tube 36, passes through the cylindrical portion 4'4, and is attached to the vapor header 40. Further, the lower end of each heat exchanger tube 38 is connected to the lower part of the tube 37.
It is guided into the interior, passes through the cylindrical portion 46 and is attached to the water supply header 39 . The cylindrical body parts 44 and 46 of the upper header 36 and the lower header 37 have fluid heads 50,
They are arranged at regular pitches corresponding to the number of heat transfer tubes 38 in the circumferential direction and axial direction of each cylindrical portion. FIG. 4 shows details of this fluid head 50. In particular, this shows the portion of the neck 36 to the top. 51 is a nozzle, 52 is a direct inspection part, 53 is a collar, and a, b, and c are welding parts.

In the cylindrical portion 44 of the upper hem 36, /zuls 51 are arranged at regular pitches in the circumferential direction and axial direction toward the inside of the upper hem 36. fluid head 5
0 has a straight pipe part 52 in its center that has the same outer diameter and inner diameter as the civil heat pipe part 54 of the heat exchanger tube 38, and is located approximately in the center of the straight pipe part 52, and one end thereof is connected to the direct pipe part 52. The other end of the nozzle 51 is composed of an outer flange of the nozzle 51 and a flange 53 having the same inner diameter. The mirror heat tube 38 consists of a heat exchanger tube section 54 existing inside the body 32 and a communication section 55 existing outside the body 32. By passing through the fluid head 50 as described above, the heat transfer tube 38 can easily pass through the body of the barrel 36 to the upper part. That is, the heat exchanger tube section 54 is connected to the direct inspection section 6.
It is connected to one end of 2 at welding part b. The other end of the straight pipe section 52 of the fluid head 50 is connected to the communication section 55 at the welded section c. The nozzle 51 and the collar 53 are connected at a welded portion a. Here welds a, b, and c
Because all of these welds are butt welded, high-quality welding is possible, and sufficient non-destructive testing can be performed, resulting in high reliability. Furthermore, by appropriately selecting the length of the nozzle 51, thermal shock generated in the cylindrical portion 44 due to sudden changes in fluid conditions inside and outside the heat transfer section 54 can be alleviated. The lower header 37 is also the same as the upper header 36 described above. Further, the direction of the fluid head 50 is determined to be either inward or outward depending on fluid conditions, thermal shock conditions, and the like. In FIG. 3, the upper end of the spiral heat transfer tube section 54 inside the steam generator 31 is extended upward to the inside of the tube 36, and then the heat transfer tube section 54 arranged in multiple layers
Five fluid heads are connected from the outermost circumferential layer to the long inner circumferential layer, and sequentially upward from the lowest fluid head 50 provided on the header 36.

By adopting such a connection order, the steam generator 31
The upper portions of the respective spiral heat exchanger tube portions 55 located above are arranged in an extremely orderly manner without intersecting each other. Similarly, the lower part of each spiral heat exchanger tube part 54 extends from the outermost layer of the heat exchanger tube part 54 toward the innermost layer to the vicinity of the lower head 37 , and then extends to the vicinity of the lower head 37 . The fuse head 50' disposed in the cylindrical part 46 of the lower header 37 is connected to the same machine as the one disposed in the cylindrical part 44 of the upper header 36 in the upward direction from the lower part. Similarly, the arrangement of the upper part of the heat transfer inspector 54 and the arrangement of the upper part of the heat transfer inspector 54
The lower portions of 4 are also arranged in an extremely orderly manner without intersecting each other. The outer upper part of the steam generator 31 has the same 0 as the fuselage 32.
A steam header 40 is arranged in the upper header 36, one end of a communication pipe section 55 is connected to each of the fluid heads 50 on the upper header 36, and the pond end of the communication pipe section 55 is connected to the steam header 401. .

In addition, a water supply header 39 is arranged at the outer lower part of the steam generator 31 and the same as the body 32, and one end of a communication pipe section 55 is connected to each of the fluid heads 50 on the lower header 37. The other end of the liaison inspector 55 is connected to the water supply header 39. The water supply header 39 is connected to the cylindrical portion 46 of the lower header 37.
The cylindrical portion 46 is arranged in an imaginary cylinder having a size that can be inserted into the cylindrical portion 46 downwardly. High-temperature sodium is introduced from the sodium inlet pipe 41 into an annular space region 58 formed between the body 32 and the inner shroud 35, and is passed through a spiral transmission line regularly arranged in multiple rows within the annular space region 58. It descends outside the heat tube 38 while heating the water inside the tube.

The sodium, which has become low temperature by heating the water, flows out of the steam generator 31 through a sodium outlet pipe 42 attached to the lower part of the body 32. On the other hand, the water supply header 39
The water introduced into the tube passes through the lower connecting pipe section 55, then rises in the heat transfer section 54 in an upward direction without reversing its flow, and is mixed with high-temperature sodium that descends through the annular space region 58. It becomes steam by exchanging heat.

This steam passes through the upper connecting pipe section 55 to the steam pipe 40.
and then sent to a steam turbine (not shown). During operation of the steam generator, sodium liquid levels 56 and 57 are formed in the body 32.

A liquid level 56 is formed in the annular space region 58 and a liquid level 57 is formed in the inner shroud 35 . The interior of the body 32 above the liquid levels 56 and 57 is filled with argon, an inert gas. If accidental contact occurs between water and sodium, a rupture disc (not shown) attached to the end of the discharge pipe 47 ruptures, and the reaction products are discharged from the discharge pipe 47. In the steam generator 31, when it is necessary to pull out the east side of the heat transfer tube 38 from the body 32 for maintenance, inspection, or repair, the sodium in the body 32 can be drained from the drain pipe 59 provided at the lower end of the lower head plate 34. At the same time, the water in the heat transfer tubes 38 is drained, and the water in the body 3 is drained as shown in FIG.
2 (the part shown by the dashed-dotted line EI), and insert a cutter through the gap between the connecting pipe part 55 and the inside of the lower header 37 at the part of the lower header 37 shown by the dashed-dotted line E2. Then, the cylindrical portion 46 is cut.

The portion indicated by the one-dot chain line E2 is below the position of the lowest fluid head 50 disposed in the cylindrical portion 46.
As a result, as shown in FIG. 5, the upper end plate 33, the upper header 36, the steam header 40, the connecting pipe section 55, the heat transfer tube section 54, the internal shroud 35, the lower end header 37, and the water supply header 39. etc. can be pulled out from the fuselage 32.

At this time, since the contact section 55 and the water supply header 39 at the lower part of the heat transfer tube 38 are both arranged in a virtual sill extending downward from the cylindrical section 46 of the lower header 37, the assembly is There is no problem when withdrawing from 32. Furthermore, even if the number of heat exchanger tubes 38 increases due to an increase in the capacity of the steam generator, by increasing the length of the cylindrical portion 46, the arrangement of the fluid heads 50 can be easily performed, and the heat exchanger tubes can be connected from inside the body 32. 38 can be easily installed. Since the pitch between the fluid heads 50 is sufficient, the heat exchanger tubes 3
8 is also easy to install. When the inspection and repair work of the heat exchanger tubes 38 is completed, the assembly is lowered back to the original position, and then butt welded at the position where it was cut when pulled out, so that the original state can be restored.

According to the embodiment of the present invention, the inside of the heat exchanger tube can be completely drained, and the east heat exchanger tube can be easily pulled out from the body if necessary, making maintenance and inspection easy.

In addition, in this structure, the connecting pipe section 55 at the lower part of the heat transfer tube 38 for the water supply can be arranged extremely compactly by the water supply header 39 and the lower header 37, and the water supply header 39 can be arranged at the center of the lower end plate 34. Since it is only necessary to place one piece in the lower end plate 34, the diameter of the lower end plate 34 can be smaller than that of the conventional example.
Naturally, the diameter of the body 32 becomes smaller and the entire steam generator becomes more compact. Another embodiment of the invention is shown in FIG. Structures that are the same as those in the previously described embodiments are designated by the same reference numerals. 61
62 is a fuselage flange, 63 is an upper fuselage, and 64 is a lower fuselage.

In this embodiment, the fuselage 32 is separated into an upper fuselage 63 and a lower fuselage 64 by fuselage flanges 61 and 62. In this embodiment, the same effects as in the above-described embodiment can be obtained. Furthermore, the assembly 65 can be pulled out and assembled more easily. In this embodiment, the assembly 65 can be easily assembled by cutting the portion of the cylindrical portion 46 indicated by the dashed line E3 and removing the bolts (not shown) vertically attaching the fuselage flange 61 and the fuselage flange 62. , can be pulled out from inside the lower body 64. The assembly 65 includes the upper mirror plate 33, the inner shroud 35, and the upper and lower headers 36 and 37.
, a heat exchanger tube 38, a water supply header 39, a steam header 40, and an upper body 63. Although these embodiments have a structure in which the heat transfer tubes 38 are integrated into the upper header 36, this structure can also be applied to the conventional tube plate method, ring header method, etc. good. Further, the present invention can also be applied to a liquidless surface type steam generator. The upper part 36 may protrude into the body 32 like the lower part 37.

This reduces the number of curved portions of the heat transfer tube 38 that are required to cover the upper header 36, making it easier to manufacture and install the heat transfer tube 38. According to the present invention, since the heat exchanger tube does not make a U-turn, that is, it extends in the vertical direction, it is easy to drain the fluid in the heat exchanger tube.

By simply cutting the lower end and upper end end plates of a single cylindrical body provided on the lower end end plate, internal structures such as heat exchanger tubes placed inside the fuselage can be pulled out. Maintenance and inspection of the exchanger can also be easily performed. Further, it is only necessary to install one cylindrical body, so the diameter of the end plate can be small, and the heat exchanger can be made compact.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a conventional steam generator, FIG. 2 is a longitudinal sectional view of the internal structure of the steam generator shown in FIG. Fig. 4 is a detailed sectional view of the fluid head section in Fig. 3, and Fig. 5 is a longitudinal sectional view of the steam generator as an example. FIG. 6 is a longitudinal sectional view of a steam generator according to another embodiment of the present invention. Explanation of symbols, 31...Steam generator, 32...
・Body, 36... Upper header, 37... Lower header, 38... Heat transfer tube, 39...
Water supply header, 46... Cylindrical part, 47... End plate part. Figure 1 Figure 2 Figure 4 Figure 3 Figure 5 Figure 6

Claims (1)

[Claims] 1 A body having an inlet and an outlet for the heating medium and sealed at the upper and lower ends with a head plate, and a body that penetrates the head plate at the lower end and protrudes into the body, the upper end is sealed and the lower end is sealed by the body. a cylindrical body that is open to the outside of the fuselage; and a cylindrical body that is disposed within the fuselage and extends in the vertical direction; a plurality of heat exchanger tubes that penetrate the side wall of the body and further pass through the cylindrical body to reach the outside thereof; an upper header that is disposed outside the body and to which the upper ends of the heat exchanger tubes are attached;
A heat exchanger comprising a lower header disposed outside the body and having a size that can pass through the cylindrical body, and to which a lower end portion of the heat exchanger tube is attached.