JPH07181291A - Helical coil type heat exchanger - Google Patents

Abstract

PURPOSE:To improve assembling performance of heat conduction pipes and support strength and raise flexibility to the change in the specification of the heat conduction pipes by providing a cylindrical partition wall forming a heat exchanging room, a plurality of perforated plate for inserting the heat conduction pipes in the penetration holes and a ladder type supporting device for supporting the heat conduction pipes with bonding force in the radial direction. CONSTITUTION:When heat conduction pipes 25 are arranged in multiple radial layers, the heat conduction pipes 25 are supported by inserting in the penetration holes 31 in perforated plates 30 arranged with intervals in peripheral direction. The arrangement pitch angle in the peripheral direction on the perforated plates 30 is set so as not to disturb the drilling work of the penetration holes 31. In addition to the support of the heat conduction pipes 25 with the perforated plates 30 in this case, they are pinched in radial direction by arranging ladder parts between the perforated plates 3C. The ladder parts are assembled in turn after inserting the heat conduction pipes 25 in the perforated plates 30. And a downcomer cylinder 22 is arranged around an inner cylinder 21 forming a heat exchanging room 24 between itself and the inner cylinder 21 and guiding the primary water downward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical coil heat exchanger, and more particularly to improving the assemblability of heat transfer tubes.

[0002]

2. Description of the Related Art A helical coil heat exchanger can improve heat exchange efficiency by lengthening a flow path of a heat transfer tube in a heat exchange chamber. Therefore, a planned light water cooling type reactor shown in FIG. It is considered to have excellent applicability to.

In FIG. 6, reference numeral 1 is a reactor containment vessel,
2 is a reactor pressure vessel, 3 is a core, 4 is a steam generator (helical coil heat exchanger), 5 is a primary cooling water circulation pump,
6 is the suppression pool (pool water), 7 is the gas phase, 8
Is primary cooling water, 9 is a watertight container, 10 is a heat insulating layer, 11 is a water inlet, 12 is a steam outlet, and 13 is a reactor shroud.

In such a heat exchanger 4, when a plurality of layers of heat transfer tubes are arranged in the shape of a helical coil and concentrically inside the heat exchange chamber, the support load of the heat transfer tube, vibration suppression, etc. are applied. I need to do it.

As a support device for such a heat transfer tube, for example, as shown in Japanese Utility Model Laid-Open No. 2-69286 (heat transfer tube support device for heat exchanger), a plurality of layers of heat transfer tubes are radially arranged one by one by a pair of ladders. A technique for sandwiching and fixing the heat transfer tube has been proposed, and it is expected that a plurality of locations in the circumferential direction of the heat transfer tube can be supported at a relatively small pitch angle.

As another means for supporting the helical coil-shaped heat transfer tube, for example, a plurality of perforated plates extending radially outward from the inside of the heat exchange chamber are arranged at intervals in the circumferential direction. There is a technique of suppressing vibration of the heat transfer tube by sequentially passing the heat transfer tube through a large number of through holes. In this case, when assembling the heat transfer tube and the perforated plate, the heat transfer tube is bent in a curved shape, and while the through holes are opened as necessary, the heat transfer tube is sequentially passed through a large number of through holes to form a spiral. The forming operation is repeated for each of the parallel layers, and the assembly is performed by a method such as inserting a wedge or the like into a through hole at a required position and fixing the same. It is expected that if the structure in which the heat transfer tubes are supported by the perforated plate is adopted, the structure is simple and the space occupied by the supporting portion of the heat transfer tubes can be reduced, and the density of the heat transfer tubes can be increased.

[0007]

However, in the former technique of supporting the heat transfer tube by the ladder, since the occupied space of the ladder becomes relatively large, the heat transfer tube located inward in the radial direction has a problem. As a result, the heat exchange rate is reduced due to the decrease in the contact area with the heating fluid, and the labor for fixing the heat transfer tubes one by one by the ladder is likely to be great. On the other hand, with the latter technique of passing the heat transfer tube through the through hole of the perforated plate, the assembly workability is likely to be impaired due to the accumulation of the heat transfer tube working error, and the work of drilling the through hole is
When the pitch angle of the perforated plate is smaller than 90 degrees, workability is significantly impaired, and when the pitch angle is increased, the supporting strength is lowered and the fluid vibration is increased.

The present invention effectively solves the above problems, and aims to improve the assemblability of a heat transfer tube and the support strength, and to increase the flexibility with respect to changes in specifications such as the support structure of the heat transfer tube. I am trying.

[0009]

[Means for Solving the Problems] When a plurality of layers of helical coil heat transfer tubes are arranged in a radial direction in a heat exchange chamber, the heat exchanger tubes are concentrically arranged between them. Two cylindrical partition walls that form a heat exchange chamber, a plurality of perforated plates that are circumferentially spaced on the outer surface of the inner partition wall, and through which heat transfer tubes are inserted, and between the perforated plates. And a ladder type supporting device that supports the heat transfer tube by fastening force in the radial direction.

[0010]

When the heat transfer tubes are arranged in multiple layers in the radial direction, the heat transfer tubes are supported by being inserted through the through holes of the perforated plates which are arranged at intervals in the circumferential direction. The arrangement pitch angle of is set to such an extent that it does not hinder the through hole drilling work. In this case, in addition to supporting the heat transfer tubes by the perforated plates, a ladder member is arranged between the perforated plates and sandwiched in the radial direction. The ladder members are sequentially assembled after inserting the heat transfer tube into the perforated plate.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the helical coil heat exchanger according to the present invention will be described below with reference to FIGS. Also in this one embodiment, it is applied to the steam generator (helical coil type heat exchanger, heat exchanger) 4 arranged in a state of being submerged in the primary cooling water 8 inside the reactor pressure vessel 2 shown in FIG. To be done.

1 to 5, reference numeral 21 is an inner cylinder (cylindrical partition wall), 22 is a downcomer cylinder (cylindrical partition wall), 23 is an outer cylinder, 24 is a heat exchange chamber, 25 is a heat transfer tube, 3
Reference numeral 0 is a perforated plate, and 40 is a ladder type supporting device.

The inner cylinder 21 is arranged so as to surround the reactor shroud 13, and a downcomer cylinder 22, an outer cylinder 23, a perforated plate 30, a ladder type support device 40, etc. are attached to the outer surface of the inner cylinder 21.

The downcomer cylinder 22 is concentrically arranged around the inner cylinder 21, and a heat exchange chamber 24 is formed between the downcomer cylinder 22 and the inner cylinder 21. As shown by arrows in FIG. Is directed downwards.

As shown in FIG. 2, the outer cylinders 23 are arranged around the downcomer cylinder 22 with a space therebetween, and a plurality of outer cylinders 23 for connecting the water supply port 11 shown in FIG. The hanging pipe 25a is inserted into the heat exchange chamber 24 in an isolated state.

The heat exchange chamber 24 is formed between the inner cylinder 21 and the downcomer cylinder 22, and accommodates a plurality of heat transfer tubes 25 in a helical coil shape and in a radial multi-layered state. The upper part is set in communication with the discharge side of the primary cooling water circulation pump 5 shown in FIG. 6, and the lower part is set in communication with the lower inlet of the core 3 shown in FIG.

The heat transfer tubes 25 are arranged inside the heat exchange chamber 24 in the form of a helical coil in a radial direction in multiple layers to exchange heat with the primary cooling water descending in the heat exchange chamber 24.
The water to be heated sent from the water supply port 11 shown in FIG. 6 through the hanging pipe 25a and the lower connecting pipe 25b shown in FIG. 2 is vaporized, and the steam outlet 12 is passed through the steam delivery pipe 25c (see FIG. 6). Is sent from.

As shown in FIGS. 1 to 4, the perforated plate 30 is, for example, 90 in the circumferential direction with respect to the outer surface of the inner cylinder 21.
2 is attached integrally by welding or the like at a pitch angle of 2 degrees.
As shown in FIG. 5, a large number of through holes 31 for inserting the heat transfer tubes 25 are opened, and the downcomer cylinder 22 is attached to the outer portion by the outer cylinder fixing bolt 32. Then, as shown in FIGS. 3 and 4, the heat transfer tube 25 is integrally supported by the perforated plate 30 by closely inserting and welding a wedge-shaped fixture 33 into the through hole 31.

Further, as shown in FIG. 2, the downcomer tube 2
A partition plate 34 having an annular shape is provided between the 2 and the outer cylinder 23.
It is horizontally attached by welding to the outer surface of the downcomer cylinder 22. The partition plate 34 has the outer cylinder 23 attached to the outer side thereof by an outer cylinder fixing bolt 35,
The hanging tube 25a is inserted through the part thereof. In addition,
Positioning pins 36 that adjust the protrusion size according to the screwing amount are attached to the outer side of the partition plate 34, and the tip of the positioning pins 36 are lowered on the inner peripheral surface of the reactor pressure vessel 2 when the heat exchanger 4 is installed. A guide portion 37 is provided for guiding and supporting the steady rest.

The ladder type support device 40 includes an inner cylinder 21,
A ladder support plate 41 integrally arranged so as to be positioned between the perforated plates 30 at a pitch angle of 90 degrees between the upper portions of the downcomer cylinders 22, for example, and the ladder support plate 41.
A ladder support bolt 42 that is hung up and down so that the vertical position can be adjusted, an inner ladder member 43 that is hung by the ladder support bolt 42, an outer ladder member 44 that is combined with the inner ladder member 43, and both ladder members. An assembly bolt 45 for integrating 43 and 44, an inner protrusion member 46 arranged between the inner cylinder 21 and the inner ladder member 43,
An inner engaging portion 47 formed on the outer surface of the inner protruding member 46 and the inner side surface of the inner ladder member 43 to allow the inner ladder member 43 to move vertically and to restrain the movement in the circumferential direction, and an adjacent outer ladder member. A ladder engaging portion 48 formed between the outer side portion of the inner side portion 44 and the inner side portion of the inner side ladder member 43 for permitting vertical mutual movement and restraining the movement in the circumferential direction; It is formed between an outer protruding member 49 disposed integrally with the outer downcomer cylinder 22 between the outer downcomer cylinder 22 and an inner portion of the outer protruding member 49 and an outer portion of the outer ladder member 44 at the outermost position. It has an outer engagement portion 50 that allows mutual movement in the vertical direction and restrains movement in the circumferential direction. In addition, both ladder members 43, 44
Are recesses 43a and 44a for holding the heat transfer tube 25.
Is formed.

An assembling method in the helical coil type heat exchanger having such a structure will be described below.

A plurality of perforated plates 30 and ladder support plates 41 are arranged on the outer surface of the inner cylinder 21 and attached by welding.
The stiffened first-layer heat transfer tube 25 is sequentially passed through the through holes 31 of the perforated plate 30 to finish the innermost layer into a helical coil shape. At this time, the innermost ladder member 4 of the innermost layer
The ladder support bolt 42 protruding above 3 is passed through the bolt insertion hole 41a of the ladder support plate 41 so as to protrude from the upper surface of the ladder support plate 41. In addition, the inner protruding member 46
The inner engagement portion 47 and the inner engagement portion 47 are fitted together and the circumferential direction is fixed, and the heat transfer tube 25 is fitted into each recess 43a.

An outer ladder member 44 is arranged on the outer side of the inner ladder member 43, and the two ladder members 43, 44 are integrated by a mounting bolt 45, and the heat transfer tube 25 of the first layer is formed by the recesses 43a, 44a. Hold in the radial direction. Also,
Both the rudder members 43, 44 by the positioning nut 42a.
Also, the vertical position of the heat transfer tube 25 is set.

After sandwiching the heat transfer tube 25 of the first layer, the inner ladder member 43 for the second layer is engaged with the outer side of the outer ladder member 44 of the first layer by utilizing the ladder engaging portion 48. Then, the second layer heat transfer tube 25 is helically inserted by sequentially passing through the through holes 31 of the perforated plate 30 while engaging the stiffened second layer heat transfer tube 25 with the recess 43a of the inner ladder member 43. Finish into a coil.

In this way, after the heat transfer tubes 25 up to the outermost layer after the third layer are finished in a helical coil shape, the outer ladder member 44 is arranged on the outer side thereof, and the inner ladder member 43 is mounted by the mounting bolts 45. , 44 are fastened and the heat transfer tubes 25 of the respective layers are sandwiched in the radial direction.

Then, the downcomer cylinder 22 is inserted, and the outer engagement member 50 is utilized to bring the outer projection member 49 into engagement with the outer ladder member 44 of the outermost layer, and the ladder support plate 41 is moved to the inner cylinder 21. Weld to and fix.

Further, in the outer cylinder 23, as shown in FIGS. 2 and 5, the partition plate 34 is fixed by the outer cylinder fixing bolt 35.
The inner cylinder 21, the downcomer cylinder 22, the outer cylinder 23, the heat transfer tube 25, the perforated plate 30, the ladder-type support device 40, etc. are assembled as a whole.

In the case of the example of FIG. 6, such a heat exchanger is hung down around the reactor shroud 13 in a state of being assembled except for the connection portion with the water supply port 11 and the steam outlet 12. Is installed. At this time, as shown in FIG.
When the positioning pin 36 contacts the guide portion 37, centering is performed. The hanging pipe 25a and the steam delivery pipe 25c are connected to the water supply port 11 and the steam outlet 12 after setting the position of the heat exchanger.

During operation of the heat exchanger, the primary cooling water heats between the inner cylinder 21 and the downcomer cylinder 22 (between the two partition walls 21 and 22) as indicated by the arrows in FIG. Although the exchange chamber 24 is inserted downward, a partition plate 34 is arranged between the downcomer cylinder 22 and the outer cylinder 23 at this time to prevent the primary cooling water from being inserted therethrough. Is limited to the heat exchange chamber 24, and the generation of unnecessary split flow of the primary cooling water is suppressed so that steam can be generated efficiently and uniformly.

[0030]

The helical coil heat exchanger according to the present invention has the following effects. (1) The distance between the perforated plates is set so as not to impair the workability of punching the through holes, and the heat transfer tubes are inserted through the through holes, thereby reducing obstacles when the heat transfer tubes are combined with the perforated plates. The assembling property can be improved. (2) Even when the distance between the perforated plates is widened, the support strength of the heat transfer tube can be improved by disposing and supporting the ladder type support device between them. (3) The heat transfer tube is supported to a minimum by the perforated plate, and then the ladder type support device is used to expand the application even if the specifications of the support structure of the heat transfer tube are changed, and it is flexible. You can improve your sex.

[Brief description of drawings]

FIG. 1 is a plan view of essential parts showing an embodiment of a helical coil heat exchanger according to the present invention.

FIG. 2 is a front sectional view with a part omitted showing a supporting state of a heat transfer tube by a perforated plate of FIG.

3 is a front cross-sectional view showing a fixing state of a heat transfer tube to the perforated plate of FIG. 2 with a part omitted.

FIG. 4 is a vertical cross-sectional view in which a part of the heat transfer tube is fixed to the perforated plate of FIG. 2 with a part thereof omitted.

5 is a front sectional view with a part omitted showing a supporting state of a heat transfer tube by the ladder type supporting device of FIG. 1. FIG.

FIG. 6 is a front sectional view showing a plan example of a light water cooling-type reactor.

[Explanation of symbols]

2 Reactor pressure vessel 3 Core 4 Heat exchanger (steam generator, helical coil heat exchanger) 5 Primary cooling water circulation pump 8 Primary cooling water 11 Water inlet 12 Steam outlet 13 Reactor shroud 21 Inner cylinder (cylindrical partition wall) ) 22 downcomer tube (cylindrical partition wall) 23 outer tube 24 heat exchange chamber 25 heat transfer tube 25a hanging tube 25b lower connecting tube 25c steam delivery tube 30 perforated plate 31 through hole 32 outer tube fixing bolt 33 fixing tool 34 partition plate 35 outside Cylinder fixing bolt 36 Positioning pin 37 Guide portion 40 Ladder type support device 41 Ladder support plate 41a Bolt insertion hole 42 Ladder support bolt 42a Positioning nut 43 Inner ladder member 44 Outer ladder member 43a, 44a Recessed portion 45 Assembly bolt 46 Inner protruding member 47 Inner Engagement Part 48 Ladder Engagement Part 49 Outer Projection Member 50 Outer Engaging portion

Claims (1)

[Claims] 1. A heat exchanger in which a plurality of layers of helical coil-shaped heat transfer tubes are radially spaced apart inside a heat exchange chamber, the heat exchange chambers being concentrically arranged to form a heat exchange chamber therebetween. Two cylindrical partition walls, a plurality of perforated plates that are circumferentially spaced on the outer surface of the inner partition wall and through which the heat transfer tubes are inserted, and the heat transfer tubes that are placed between the perforated plates And a ladder-type support device that supports by a directional fastening force.