JP3238382B2 - Hanging heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspended heat exchanger such as a suspended superheater / reheater tube of a boiler, wherein the non-heated portion is disposed above the ceiling tube. The improvement of the support and sealing structure applied to

[0002]

2. Description of the Related Art Boilers for power generation such as coal-fired boilers include:
Hanging heat exchangers such as hanging superheaters and reheaters are employed. As a conventional suspended heat exchange device, for example, Japanese Patent Laid-Open No. 1-300102 discloses a case where a skin casing is provided in a support frame surrounding an entire portion of a heat transfer tube protruding above a ceiling tube, and the skin casing is provided. One that is slidably mounted on a support frame has been proposed.

In this suspension type heat exchanger, a gap necessary for absorbing a difference in thermal expansion between the ceiling pipe and the heat transfer pipe is secured, and a skin casing is provided for gas sealing. As shown in FIG. 9, the skin casing 1 is sandwiched between the support frame 2 and the holding plate 3 and tightened with the bolts B1, and the holes of the skin casing 1 through which the bolts B1 are inserted are made into the stupid holes 1a. ing.

That is, since the skin casing 1 is slidable due to the stupid hole 1a at the time of thermal expansion, the skin casing is distorted due to a difference in thermal expansion due to a temperature difference between a portion near and far from the header. That can be prevented. A packing 4 is interposed between the skin casing 1 and the support frame 2 to prevent gas leakage.

[0005]

However, the above-mentioned conventional hanging heat exchanger has the following problems. That is, as shown in FIG. 10, the support frames 2 to which the skin casings are attached are fixed to each other by welding, and a large bending stress is generated also in the support frames 2 due to a difference in thermal expansion between the support frames 2 and the support frames 2. Could be distorted. The skin casing 1 is mounted so as to slide with thermal expansion.
There was an inconvenience that it was difficult to slide due to friction with Further, as shown in FIG. 11, a plurality of packings 4 are installed side by side.
When the skin casing slides, the packing 4 slides along with the skin casing, and a gap 4a is generated between the packings 4 and the gas and ash easily leak when the skin casing slides. There was a fear.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and eliminates a problem that occurs during thermal expansion, that is, alleviates bending stress applied to a support frame, improves sliding of a skin casing, and prevents gas leakage between packings. It is an object of the present invention to provide a suspension type heat exchange device capable of performing the following.

[0007]

The present invention has the following features to attain the object mentioned above. That is, in the hanging heat exchanger according to the first aspect, the upper end of the heat transfer tube is fixed to the header arranged above the ceiling tube, and the power generation suspended by the hanging rod attached to the header. A suspension type heat exchange device for a boiler, a support frame disposed around a portion of the heat transfer tube projecting above the ceiling tube,
A skin casing surrounding the entire protruding portion and slidably provided with respect to the support frame, wherein the support frame is disposed in a direction along the header and a parallel support frame; A plurality of cross support frames disposed in a direction intersecting with the shifter and connected to the parallel support frame and the header, and at least a part of the plurality of cross support frames.
Is attached so as to be rotatable around the connection portion with the parallel support frame and the header, to form a link structure ,
Rotate according to the difference in thermal expansion when the header is extended by thermal expansion
A technology that is a stress relaxation support frame that reduces the occurrence of bending stress is employed.

In this suspension type heat exchange device, at least a part of the plurality of cross support frames is attached rotatably about a connection portion between the parallel support frame and the header, thereby forming a stress constituting a link structure. Since it is a relaxation support frame, the header
Even if a difference in thermal expansion occurs when expanded by expansion, the stress relaxation support frame can be rotated according to the difference in thermal expansion to reduce the occurrence of bending stress.

According to a second aspect of the present invention, there is provided the hanging type heat exchange apparatus according to the first aspect, wherein the plurality of cross-supporting frames are connected to at least a portion near an end of the header. However, the technique of the stress relaxation support frame is adopted.

In this suspension type heat exchanger, since at least one of the plurality of cross support frames connected near the end of the header is a stress relieving support frame, there is a significant difference in thermal expansion between the plurality of cross support frames. The bending stress can be effectively reduced in the vicinity of the end.

According to a third aspect of the present invention, there is provided the hanging type heat exchanger according to the first or second aspect, wherein the stress relaxation supporting frame is connected by bolts. .

In this suspension type heat exchange device, since the stress relaxation support frame is connected by bolting, a rotatable connection portion can be obtained with a simple and easy-to-install structure.

[0013] In the hanging heat exchanger according to the fourth aspect, the upper end of the heat transfer tube is fixed to the header arranged above the ceiling tube, and is suspended by the hanging rod attached to the header. A suspended heat exchange device for a power generation boiler, comprising: a support frame disposed around a portion of the heat transfer tube projecting above the ceiling tube; and the support frame surrounding the entire projecting portion. A skin casing slidably provided with respect to the skin casing, the skin casing is sandwiched between a holding plate and the support frame, between the skin casing and the holding plate and the support frame, A technology is employed in which low friction members each having a lower coefficient of friction with respect to the skin casing than the holding plate and the support frame are interposed.

In this suspension type heat exchanger, low friction members having a lower coefficient of friction with respect to the skin casing than the holding plate and the support frame are interposed between the skin casing and the holding plate and the support frame. Compared to the case where the holding plate and the support plate are in direct contact with the skin casing,
The friction due to friction is low, and the skin casing slides smoothly.

According to a fifth aspect of the present invention, in the hanging type heat exchange apparatus, at least the low friction member interposed between the skin casing and the support frame includes: A technique that is a packing that closes a gap between the skin casing and the support frame is employed.

In this suspension type heat exchanger, at least the low friction member interposed between the skin casing and the support frame is a packing for closing the gap between the skin casing and the support frame. It is also possible to prevent gas and ash from leaking from the gap between the gas and ash.

In the hanging heat exchanger according to the sixth aspect, the upper end of the heat transfer tube is fixed to the header arranged above the ceiling tube, and is suspended by the hanging rod attached to the header. A suspended heat exchange device for a power generation boiler, comprising: a support frame disposed around a portion of the heat transfer tube projecting above the ceiling tube; and the support frame surrounding the entire projecting portion. A skin casing provided slidably with respect to the skin casing, wherein the skin casing has a coefficient of friction with respect to the skin casing between the holding plate and the support frame.
A technique is employed in which the packing is sandwiched via a packing lower than the holding plate and the support frame , and the packing is formed integrally from one end to the other end of the skin casing at least along the header.

In this suspension type heat exchanger, the skin casing is sandwiched between the holding plate and the support frame via packing, and the packing is integrally formed at least from one end to the other end of the skin casing along the header. Because it is formed,
When the skin casing slides, there is no boundary between the packings in the sliding direction (that is, the direction along the header), and there is no possibility that a gap is generated between the packings and gas or ash easily leaks.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of a suspended heat exchanger according to the present invention will be described with reference to FIGS. In these figures, reference numeral 11 denotes a heat transfer tube, 1
2 denotes a ceiling tube, 13 denotes a header, 14 denotes a hanging rod, and 15 denotes a support frame.

The suspended heat exchanger of the present embodiment is a suspended superheater / reheater of a boiler for power generation, and as shown in FIG. It is fixed to a header 13 disposed above by welding, and is suspended from a boiler support steel frame (not shown) by a suspension rod 14 attached to the header 13 and is entirely supported. The suspended heat exchange device is provided with a support frame 15 disposed around a portion of the heat transfer tube 11 protruding above the ceiling tube 12, and is slidable with respect to the support frame 15 surrounding the entire protruded portion. And a skin casing 1 provided in the main body.

At a portion where the heat transfer tube 11 penetrates the ceiling tube 12, a receiving plate 16 is provided on the ceiling tube 12 so as to prevent ash from leaking through a gap in the penetrating portion. By laying the heat insulating material 17 and further mounting the refractory material 18 on the upper surface thereof, the heat insulating material 17 is prevented from scattering.

The receiving plate 16 is provided so that the heat insulating material 17 does not fall from the gap of the ceiling pipe 12.
It is possible to freely move in the front-rear and left-right directions with respect to the ceiling pipe 12 simply by placing it on the ceiling pipe 12.

The support frame 15 includes a plurality of parallel support frames 15a disposed in parallel along the header 13 and a header 13
A plurality of cross support frames 15b arranged in a direction intersecting with each other and connected to the parallel support frame 15a and the header 13;
The skin casing 1 is configured in a lattice shape corresponding to the size of one sheet. When the support frame 15 is attached to the header 13 with a large inclination, a large stress is generated. For the purpose of reducing this stress, the support frame 15 is mounted in a substantially horizontal state.

The cross support frame 15b is, as shown in FIG.
It is attached to the parallel support frame 15a and the header 13 by bolting with bolts B2 and nuts (not shown),
It is rotatable around the connection between the parallel support frame 15a and the header 13. That is, the connection between the support frames is bolted to form a link mechanism. The mounting hole formed in the skin casing 1 is a stupid hole 1a, and is set so as to be able to absorb the difference in thermal expansion of one skin casing.

As shown in FIG. 3, the skin casing 1 is sandwiched between the support frame 15 and the holding plate 19, and the skin casing 1 is held between the skin casing 1 and the holding plate 19 and the support frame 15. The friction coefficient against
And packing (low friction member) 2 lower than support frame 15
0 is interposed. Such packing 20
For example, a sheet-like gasket in which rubber is applied to a glass woven fabric containing a metal wire or the like is employed.

FIG. 4 shows a test result in which a friction coefficient with respect to a tightening torque when the skin casing 1 is tightened with a bolt is determined. As can be seen from this graph, only one packing, namely skin casing 1
(A and B in the figure (A and B are packings made of different materials)) and the case of the present embodiment in which packings 20 are arranged on both sides of the skin casing 1 (C in the figure (using packing made of the same material as A)) has the smallest friction coefficient in the case of the present embodiment.

As shown in FIG. 5, the packing 20 disposed along the header 13 is formed integrally (sequentially) from one end to the other end of the skin casing 1, that is, as a single piece. Further, as shown in FIG.
The length is set to the same length as one side of the skin casing 1 , the surface pressure is made uniform, the friction coefficient is reduced, and the skin casing 1
Makes it slippery.

In the hanging type heat exchanger of the present embodiment, the cross support frame 15b is rotatably attached to the parallel support frame 15a and the header 13 by bolts around the connection portion thereof. Even if 13 expands due to thermal expansion, the cross support frame 15b functions as a stress relaxation support frame, and can rotate according to the difference in thermal expansion to reduce the generation of bending stress.

In this embodiment, the cross support frame 15b
Are all bolted as the above-mentioned stress relaxation support frame, but since the difference in thermal expansion is small in the central portion of the header 13,
By using at least one of the plurality of cross support frames 15b connected near the end of the header 13 as a stress relieving support frame, bending stress can be reduced in the vicinity of the end of the header 13 where a difference in thermal expansion is remarkable. Can be relaxed.

Further, between the skin casing 1 and the holding plate 19 and the support frame 15, packings 20 having a lower coefficient of friction with respect to the skin casing 1 than the holding plate 19 and the support frame 15 are interposed. Compared to the case where the holding plate 19 and the support frame 15 are in direct contact with the casing 1, the resistance due to friction is lower and the skin casing 1 slides smoothly.

Further, since the packing 20 disposed along the header 13 is formed integrally from one end to the other end of the skin casing 1, when the skin casing 1 slides, the packing 20 is moved in the sliding direction. There is no boundary, and there is no possibility that gas or ash easily leaks due to a gap between packings. In this embodiment, the packing 20 in the direction perpendicular to the packing 20 in the direction parallel to the header 13 is used.
Although the packing is constituted by a plurality of these, the packing may be constituted by one packing (integral).

Hereinafter, a second embodiment of the suspension type heat exchanger according to the present invention will be described with reference to FIGS.

The difference between the second embodiment and the first embodiment is that, in the first embodiment, the skin casing 1 is attached to the header 13 via the support frame 15 and is slidable by the stupid hole 1a. On the other hand, in the second embodiment, as shown in FIG. 7, the entire structure from the ceiling pipe to the header 13 is covered with a skin casing 21.
As shown in FIG. 8, the point is that the skin casings 21 are connected to each other by a stretchable expansion 22.

That is, in the present embodiment, the skin casings 21 are connected to each other by the expansions 22 formed of a ductile material into a corrugated cross section and made expandable in the direction in which the skin casings 21 thermally expand. The expansion 22 expands and contracts at the time of thermal expansion, so that thermal expansion can be absorbed.

[0035]

According to the present invention, the following effects can be obtained.
According to the hanging type heat exchange device of the first aspect, at least a part of the plurality of cross support frames is rotatably mounted around a connection portion between the parallel support frame and the header, thereby forming a link structure. None, thermal expansion when the header is extended by thermal expansion
Since the stress relief support frame pivots according to the difference to reduce the occurrence of bending stress, even if thermal expansion occurs, the stress relaxation support frame pivots according to the difference in thermal expansion to reduce the occurrence of bending stress. And reliability can be improved.

According to the hanging heat exchanger of the second aspect, since at least one of the plurality of cross support frames connected near the end of the header is the stress relieving support frame, the thermal expansion difference can be reduced. Bending stress can be effectively relieved in the vicinity of the end of the header that is noticeably generated.

According to the third aspect of the present invention, since the stress relieving support frame is connected by bolting, the rotatable connection portion can be obtained with a simple and easy-to-install structure. .

According to the hanging heat exchanger of the fourth aspect, a low-friction member having a lower coefficient of friction with respect to the skin casing than the holding plate and the supporting frame is provided between the skin casing and the holding plate and the supporting frame. Since they are interposed, the skin casing can be slid more smoothly than in the case where the pressing plate or the support plate is in direct contact with the skin casing, and the difference in thermal expansion can be favorably reduced.

According to the hanging heat exchanger of the fifth aspect, at least the low friction member interposed between the skin casing and the support frame is a packing for closing a gap between the skin casing and the support frame. In addition to the friction reducing effect, the gas leakage preventing effect can be obtained.

According to the hanging heat exchanger of the sixth aspect, the skin casing is sandwiched between the holding plate and the support frame via the packing, and the packing is at least one end of the skin casing along the header. Since the skin casing is slid, the gap does not occur even if the skin casing slides, so that gas leakage can be prevented.

[Brief description of the drawings]

FIG. 1 is a partially cutaway overall perspective view showing a first embodiment of a hanging heat exchanger according to the present invention.

FIG. 2 is a plan view showing a connection structure of a support frame in the first embodiment of the hanging heat exchange device according to the present invention.

FIG. 3 is a side view of a main part showing a mounting structure of a skin casing in the first embodiment of the hanging heat exchanger according to the present invention.

FIG. 4 is a graph showing a test result of a friction coefficient with respect to a tightening torque in the case of a single packing and a double packing in the first embodiment of the hanging heat exchanger according to the present invention.

FIG. 5 is a main part plan view showing the arrangement of the packing in the first embodiment of the hanging type heat exchange device according to the present invention.

FIG. 6 is a main part plan view showing an arrangement of the holding plate in the first embodiment of the hanging-type heat exchange device according to the present invention.

FIG. 7 is a schematic overall perspective view showing a second embodiment of a suspended heat exchange device according to the present invention.

FIG. 8 is a cross-sectional view showing an expansion in a second embodiment of the hanging heat exchanger according to the present invention.

FIG. 9 is a side view of a main part showing a mounting structure of a skin casing in a conventional example of a hanging type heat exchange device according to the present invention.

FIG. 10 is a plan view showing a connection structure of a support frame in a conventional example of a hanging-type heat exchange device according to the present invention.

FIG. 11 is a plan view of a main part showing an arrangement of a packing at the time of thermal expansion in a conventional example of the hanging type heat exchanger according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 21 Skin casing 11 Heat transfer tube 12 Ceiling tube 13 Header 14 Hanging bar 15 Support frame 15a Parallel support frame 15b Cross support frame 19 Holding plate 20 Packing (low friction member) B2 bolt

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koichiro Otsubo 1-1, Akunouramachi, Nagasaki-shi, Nagasaki Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (72) Inventor Masaaki Fujita 2-5-1 Marunouchi, Chiyoda-ku, Tokyo (56) References JP-A-1-300102 (JP, A) JP-A-3-235097 (JP, A) JP-A-1-284643 (JP, A) JP-A-11-223303 ( JP, A) JP7-38568 (JP, U) JP2, 54075 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F22B 37/24 F22B 37/36 F28F 9/013

Claims (6)

(57) [Claims] An upper end of a heat transfer tube is fixed to a header arranged above a ceiling tube, and a suspended heat exchanger of a power generation boiler suspended by a hanging rod attached to the header. A support frame provided around a portion of the heat transfer tube protruding above the ceiling tube; and a skin casing surrounding the entire protruding portion and slidably provided with respect to the support frame. The support frame comprises: a parallel support frame disposed in a direction along the header, and a plurality of support frames disposed in a direction intersecting the header and connected to the parallel support frame and the header. of a cross support frame, at least some of said plurality of cross support frame, the parallel supporting frame and the pipe pulling the connection portion center pivotally attached form a link structure, said tube Fever is fever
Rotating according to the difference in thermal expansion when expanded by expansion, the bending stress
A suspension type heat exchange device, which is a stress relaxation support frame for mitigating generation . 2. The hanging heat exchange device according to claim 1, wherein at least one of the plurality of cross support frames connected to at least a portion near the end of the header is the stress relaxation support frame. Characteristic hanging heat exchanger. 3. The hanging heat exchange device according to claim 1, wherein the stress relaxation support frame is connected by bolts. 4. A hanging heat exchanger for a power generation boiler, wherein an upper end of a heat transfer tube is fixed to a header arranged above a ceiling tube and suspended by a hanging rod attached to the header. A support frame provided around a portion of the heat transfer tube protruding above the ceiling tube; and a skin casing surrounding the entire protruding portion and slidably provided with respect to the support frame. The skin casing is sandwiched between a holding plate and the support frame, and the coefficient of friction with respect to the skin casing is between the skin casing and the holding plate and the support frame. A suspended heat exchange device wherein lower low friction members are interposed. 5. The packing according to claim 4, wherein at least the low friction member interposed between the skin casing and the support frame closes a gap between the skin casing and the support frame. A hanging heat exchanger. 6. A suspended heat exchanger for a power generation boiler, wherein an upper end of a heat transfer tube is fixed to a header arranged above a ceiling tube and suspended by a hanging rod attached to the header. A support frame provided around a portion of the heat transfer tube protruding above the ceiling tube; and a skin casing surrounding the entire protruding portion and slidably provided with respect to the support frame. The skin casing is provided between a holding plate and the support frame.
In addition, the coefficient of friction for the skin casing
A suspended heat exchange device, which is sandwiched via a packing lower than a support frame , wherein the packing is integrally formed at least from one end to the other end of the skin casing along the header.