JP2000018501A - Heat-transfer pipe structure of waste heat recovery boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve assembling efficiency and prevent heat-transfer pipes from resonating owing to air-column oscillation with fluidization of exhaust gas in operation. SOLUTION: A required number of headers 10, 10' parallelly arranged in the flowing direction of exhaust gas and heat-transfer pipes 3a, 4a, 5a connected to the headers 10, 10" are formed to be one block 20. Both breadthwise side faces of a casing crossing the exhaust 1 flow direction at right angles in each block 20 are covered with vibration-proofing plates 21, and the vibration-proofing plates 21 are connected to each other by T-bar shaped connection members 22 arranged at every vertically required distance. Further, support members for bundles of pipes, regulating the horizontal movement of respective heat- transfer pipes 3a, 4a, 5a are arranged at vertically required positions of these pipes 3a, 4a, 5a of each-block 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat transfer tube structure of an exhaust heat recovery boiler.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a conventional waste heat recovery boiler. Exhaust gas 1 from a gas turbine (not shown) driven by using natural gas, light oil or the like as a fuel is shown from left to right in FIG. On the path of the exhaust gas flow path 2 to be conducted, a heat exchanger 6 arranged in the order of the economizer 3, the evaporator 4, and the superheater 5 from the downstream side (right side in FIG. 6) is provided to generate steam. The steam turbine is driven by the steam generated in the exhaust heat recovery boiler.
Is discharged to the outside from a chimney (not shown) on the downstream side.

As shown in FIG. 6, the exhaust heat recovery boiler has the heat exchange unit 6 disposed in a casing 12 through which the exhaust gas 1 flows. There are provided partition walls 9, 9 'for partitioning the inside where the exchange part 6 is disposed and the exhaust gas 1 flows and the outside thereof, and the upper and lower portions of the partition walls 9, 9' are respectively provided with the above-mentioned nodes. Header enclosures 11, 11 '(maintenance spaces) for accommodating various headers 10, 10' for supplying and removing water and steam to the charcoal unit 3, the evaporator 4, and the superheater 5 are formed.

The headers 10 and 10 'are arranged in a horizontal direction perpendicular to the flow direction of the exhaust gas 1 (a direction perpendicular to the plane of FIG. 6).
And a plurality of headers 11 and 11 ′ in the casing 12 are arranged in the upper and lower header enclosures 11 and 11 ′ in the horizontal direction orthogonal to the exhaust gas 1 distribution direction and the exhaust gas 1 distribution direction, respectively. The upper and lower ends of the heat transfer tubes 3a, 4a, 5a extending vertically are connected.

A steam drum 13 is provided on the upper part of the casing 12, and the steam drum 13 has a heat transfer pipe 3a (water supply heating pipe) at the last stage (left end in FIG. 6) of the economizer 3.
Is connected to the header 10 through the partition wall 9.
Are connected via a heating water pipe 14.

Further, an upper end of a downcomer 15 extending downward is connected to the bottom of the steam drum 13. The lower end of the downcomer 15 passes through the lower partition wall 9 'and surrounds the lower header. 11 ′, the horizontal portion 15a is bent horizontally.
The heat transfer tube 4a (evaporation tube) of the evaporator 4 is connected via a header 10 ', and the header 10 provided at the upper end of the heat transfer tube 4a is connected to the steam drum 13 via a steam return tube 16. It is connected. Further, the steam drum 13
Is connected to a header 10 attached to a heat transfer tube 5a (superheater tube) of the superheater 5 via a steam supply tube 17.

[0007] In Fig. 6, reference numeral 18 denotes a water supply pipe connected to the economizer 3, and 19 denotes a steam pipe connected to the superheater 5.

The water supplied from the water supply pipe 18 is heated by the heat transfer pipe 3a of the economizer 3, supplied to the steam drum 13 by the heated water pipe 14, and separated into water and steam.

The water separated at the lower portion of the steam drum 13 descends through the downcomer 15 and rises from the lower horizontal portion 15a to the inside of the heat transfer tube 4a of the evaporator 4, where the water is heated to form steam. The steam is returned from the steam return pipe 16 to the steam drum 13.
The steam separated at the upper part in the steam drum 13 is supplied to the heat transfer tube 5 a of the superheater 5 by the steam supply pipe 17 and is superheated, and is turned into superheated steam and supplied to the destination by the steam pipe 19. ing.

A space 8 for maintenance or the like is provided in the heat exchange section 6 at a required interval in the flow direction of the exhaust gas 1, and the space 8 allows the heat transfer tubes 3a,
4a and 5a form a plurality of heat transfer tube units 7.

The heat transfer tubes 3a, 4a, 5a are arranged in a zigzag manner in front and rear, right and left, respectively.
a, 4a, and 5a are provided vertically independently on the lower header 10, respectively, so that the weight of each of the heat transfer tubes 3a, 4a, and 5a is supported by the lower header 10 '. Has become.

By the way, conventionally, when assembling the exhaust heat recovery boiler as described above, as shown in FIG.
A plurality of heat transfer tubes 3a, 4a, 5a are carried into the casing 12 in a row for each unit of each of the headers 10, 10 'connected in a panel shape.

[0013]

However, as described above, when assembling the exhaust heat recovery boiler, a unit of each of the headers 10, 10 'in which a plurality of heat transfer tubes 3a, 4a, 5a are connected in a panel shape, respectively. One row of casing 12 for each
It takes a lot of time and effort to bring them inside,
It had the disadvantage of poor work efficiency.

In addition, the heat recovery boiler as described above has been increasing in size in recent years, and the vertical length of the heat transfer tubes 3a, 4a, 5a has been increased.
When the length of the heat transfer tubes 3a, 4a, 5a becomes longer,
a and 5a are approximately φ31.8 [mm] to φ50.8.
The heat transfer tubes 3a, 4a, and 5a may be resonated by air column vibrations caused by the flow of the exhaust gas 1 during operation because the tubes are formed of thin tubes of about [mm] and are self-supporting. Was.

In view of such circumstances, the present invention can improve the working efficiency at the time of assembly and prevent the heat transfer tube from resonating due to air column vibration accompanying the flow of exhaust gas during operation. It is an object of the present invention to provide a heat transfer tube structure of an exhaust heat recovery boiler that can be used.

[0016]

SUMMARY OF THE INVENTION According to the present invention, a header extending in a horizontal direction perpendicular to the exhaust gas flow direction is provided at a required upper and lower position in a casing through which the exhaust gas flows, and a header extending in the horizontal direction perpendicular to the exhaust gas flow direction and the exhaust gas flow direction. And a plurality of heat transfer tubes extending vertically and having upper and lower ends connected to the header in the casing. The required number of headers arranged side by side in the exhaust gas flow direction and the heat transfer tubes connected to the headers constitute one block, and both sides of the casing in the width direction of the casing orthogonal to the exhaust gas flow direction for each block are subjected to vibration isolation. Cover with a plate, and between the vibration isolating plates,
A tube bundle supporting member for restricting the horizontal movement of each heat transfer tube is disposed at a required vertical position of the heat transfer tube of each block, while being connected by a connecting member arranged at a required interval in the vertical direction. The present invention relates to a heat transfer tube structure of an exhaust heat recovery boiler.

According to the above means, the following effects can be obtained.

When assembling the exhaust heat recovery boiler, it is possible to carry the header and the heat transfer tubes into the casing in block units. As compared with a case where the headers are connected one by one into the casing for each header unit, the time is shortened without any trouble and the work efficiency is improved.

Further, even if the exhaust heat recovery boiler becomes large and the length of the heat transfer tube becomes long, both side surfaces in the casing width direction orthogonal to the exhaust gas flow direction of each block are covered with a vibration isolating plate. The pipe bundle support member that regulates the horizontal movement of each heat transfer tube is provided at a required position in the vertical direction of the heat transfer tube of each block while connecting the spaces by a connecting member disposed at a required interval in the vertical direction. Since it is disposed, the inside of the casing is partitioned in the casing width direction orthogonal to the exhaust gas flow direction by the vibration isolating plate, and each heat transfer tube is restricted from moving in the horizontal direction by the tube bundle supporting member. Thus, the occurrence of air column vibration accompanying the flow of exhaust gas during operation is suppressed, and the occurrence of resonance of the heat transfer tube is also avoided.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 5 show an example of an embodiment of the present invention. In the drawings, the portions denoted by the same reference numerals as those in FIGS. 6 and 7 represent the same components, and the basic configuration is as follows. 6 and FIG. 7, the feature of this example is that, as shown in FIG. 1 to FIG. 10 ′ and the heat transfer tubes 3 a, 4 a, 5 a connected to the headers 10, 10 ′ constitute one block 20, and prevent both sides in the width direction of the casing 12 orthogonal to the exhaust gas 1 flow direction of each block 20. The vibration isolating plates 21 are covered with a vibration plate 21, and the vibration isolating plates 21 are connected to each other by a T-bar-shaped connecting member 22 arranged at a required interval in the vertical direction.
a, 4a, and 5a, the heat transfer tubes 3a,
The point is that a tube bundle support member 23 for restricting the horizontal movement of 4a and 5a is provided.

As shown in FIGS. 1, 3 and 4, the vibration isolating plate 21 has a bracket 26 fixed to both ends of a lower header 10 'disposed on a header receiving member 24 via a saddle 25. The connecting members 22 are arranged and tightened with the bolts 28 so that both end edges of the vibration isolating plate 21 are bridged between the folded flange portions 21a. Heat transfer tubes 3
a, 4a, and 5a are bundled together.

As shown in FIGS. 3 to 5, the tube bundle supporting member 23 is provided on two L-shaped plate members 23a and 23b, respectively, with spiral fins 3b, 4b and 5b (FIGS. 3 and 4).
In FIG. 2, only the outline is omitted by imaginary lines) to form a notch 29 corresponding to the heat transfer tubes 3a, 4a, 5a provided integrally, and the L in which the notch 29 is formed is formed. The two heat-transfer tubes 3
a, 4a, and 5a are joined so as to be sandwiched from both sides and joined in a substantially inverted U-shape, and a spiral fin 3b of the heat transfer tubes 3a, 4a, and 5a is provided near the notch 29 as shown in FIG. , 4b, 5b, and a casing 12 which is fixed to the clip member 30 and is orthogonal to the exhaust gas 1 flowing direction of the tube bundle supporting member 23.
As shown in FIG. 4, both end portions in the width direction are arranged so as to span the flange portion of the channel member 31 integrally arranged so as to extend in the horizontal direction at a required position in the vertical direction of each vibration isolating plate 21, As shown in FIG. 5, the tube bundle supporting members 23 adjacent to each other in the flow direction of the exhaust gas 1 are in contact with each other, so that the horizontal movement of each heat transfer tube 3a, 4a, 5a is controlled by the tube bundle supporting member. 23.

Next, the operation of the illustrated example will be described.

When assembling the exhaust heat recovery boiler, the headers 10, 10 'and the heat transfer tubes 3a, 4
a, 5a can be carried into the casing 12, so that each header 1 in which a plurality of heat transfer tubes 3a, 4a, 5a are connected in a panel shape as in the related art.
Compared to the case of carrying in the casing 12 one row at a time for each unit of 0 and 10 ', the time is shortened without labor and the work efficiency is improved.

Further, the exhaust heat recovery boiler becomes large, and the heat transfer tubes 3
a, 4a, and 5a, each block 20
Both sides of the casing 12 in the width direction that are orthogonal to the flow direction of the exhaust gas 1 are covered with a vibration isolating plate 21, and a connecting member 22 that connects the vibration isolating plates 21 at a required interval in the vertical direction is provided, and each of the blocks Since a tube bundle support member 23 for restricting the horizontal movement of each heat transfer tube 3a, 4a, 5a is provided at a required vertical position of the heat transfer tubes 3a, 4a, 5a, the vibration isolating plate 21 is provided. As a result, the inside of the casing 12 is partitioned in the width direction of the casing 12 orthogonal to the flow direction of the exhaust gas 1, and the heat transfer tubes 3 a, 4 a, 5 a are restricted in the horizontal direction by the tube bundle supporting member 23, This suppresses the occurrence of air column vibration due to the flow of the exhaust gas 1 during operation, and the heat transfer tubes 3a, 4
It is also possible to prevent a and 5a from resonating.

In this way, it is possible to improve the working efficiency at the time of assembling, and to prevent the heat transfer tubes 3a, 4a, 5a from resonating due to air column vibration accompanying the flow of the exhaust gas 1 during operation. .

The structure of the heat transfer tube of the exhaust heat recovery boiler according to the present invention is not limited to the above-described example, but various modifications can be made without departing from the scope of the present invention. is there.

[0029]

As described above, according to the heat transfer tube structure of the exhaust heat recovery boiler of the present invention, it is possible to improve the working efficiency at the time of assembling, and to reduce the air column vibration accompanying the flow of the exhaust gas at the time of operation. In addition, an excellent effect of preventing the heat transfer tube from resonating can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of an example of an embodiment of the present invention.

FIG. 2 is a plan view of an example of an embodiment of the present invention.

FIG. 3 is an enlarged side view of a main part of an example of an embodiment of the present invention, and is a view corresponding to a part III in FIG. 1;

4 is a view taken in the direction of arrows IV-IV in FIG. 3;

FIG. 5 is a perspective view illustrating a tube bundle supporting member according to an example of an embodiment of the present invention.

FIG. 6 is a side sectional view illustrating an example of a conventional exhaust heat recovery boiler.

FIG. 7 is a perspective view showing a unit of a panel carried into a casing when assembling an example of a conventional exhaust heat recovery boiler.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exhaust gas 3a Heat transfer tube 4a Heat transfer tube 5a Heat transfer tube 10 Header 10 'Header 12 Casing 20 Block 21 Vibration-proof plate 22 Connecting member 23 Tube bundle support member

Claims (1)

[Claims] 1. A plurality of headers extending in a horizontal direction perpendicular to the exhaust gas flow direction are arranged in parallel in the horizontal direction perpendicular to the exhaust gas flow direction and in the exhaust gas flow direction at predetermined upper and lower positions in a casing through which the exhaust gas flows. ,
A heat transfer tube structure of an exhaust heat recovery boiler in which a large number of heat transfer tubes extending vertically and having upper and lower ends connected to the header are arranged in the casing, and are arranged side by side in the exhaust gas flow direction. The required number of headers and the heat transfer tubes connected to the headers are made into one block, and both side surfaces in the casing width direction orthogonal to the exhaust gas flow direction of each block are covered with a vibration isolating plate. Are connected by connecting members arranged at required intervals in the vertical direction, and a tube bundle supporting member for restricting the horizontal movement of each heat transfer tube is provided at a required position in the vertical direction of the heat transfer tube of each block. A heat transfer tube structure for an exhaust heat recovery boiler, which is provided.