JP2002071103A - Support structure for heat transfer tube of exhaust heat recovery boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support structure for a heat transfer tube of an exhaust heat recovery boiler in which an upper header may not be required, a tube joint can be reduced, air does not need to be purged, an upper connecting tube is not necessary, the increase of weight or cost can be avoided, the welding work of fitting, etc., is not necessary and the heat transfer tube can be assuredly supported while simplifying a manufacture. SOLUTION: The upper end parts of the heat transfer tube 11 at parts where fluid falls from its rising state in the upper part of the heat transfer tube 11 are directly connected to U-bends 18 as joint members. In the upper part of a casing 2, support beams 19 are disposed so as to extend widthwise the casing. The U-bends 18 are suspended and supported by U-bolts 20 serving as fastening members attached to the support beams 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat transfer tube support structure for an exhaust heat recovery boiler.

[0002]

2. Description of the Related Art In general, in a combined cycle power plant or the like, an exhaust heat recovery boiler is used as a heat source for generating exhaust steam from a gas turbine or the like for driving steam for a steam turbine or steam for a process.

FIG. 7 shows an example of a general waste heat recovery boiler. Reference numeral 1 denotes a horizontal type natural heat recovery type heat recovery boiler.
A superheater 3, a high-pressure evaporator 4, a denitration device 5, a high-pressure economizer 6, a low-pressure evaporator 7, and a low-pressure economizer 8 are arranged in this order. However, a low-pressure steam drum 10 is provided above the low-pressure evaporator 7, and the high-temperature exhaust gas flowing into the exhaust heat recovery boiler 1 from a gas turbine (not shown) or the like is supplied to the superheater 3 and the high-pressure evaporator. 4, the exhaust gas from which the nitrogen oxides have been removed and the nitrogen oxides have been removed in the denitration device 5,
It sequentially passes through the high-pressure economizer 6, the low-pressure evaporator 7, and the low-pressure economizer 8, exchanges heat with the internal fluid in each heat transfer tube, and evaporates at each pressure in the high-pressure steam drum 9 and the low-pressure steam drum 10. The two-phase flow generated in the vessel flows in and is separated into steam and water.

[0004] Such a natural circulation type waste heat recovery boiler 1
Compared with the forced circulation type waste heat recovery boiler, a circulation pump is not required, and in addition to the advantage that power in the plant can be reduced, the height from the ground to the top of the boiler can be kept low. Since it has advantages such as being able to have a self-supporting structure, it is adopted in many combined cycle power plants.

[0005] In the case of the exhaust heat recovery boiler 1 as described above, examples of the heat transfer tubes constituting the economizer include those shown in FIGS. 8 and 9.

[0008] In each case, a large number of heat transfer tubes 11 shown in FIGS. 8 and 9 are arranged inside the casing 2 so as to extend in the vertical direction. The part is connected to the lower pipe 13, but FIG.
In the case of the example shown in (1), the fluid introduced into the heat transfer tube 11 from the inlet pipe 14 first descends in the heat transfer pipe 11 as a downcomer, makes a U-turn upward in the lower pipe 13, and rises as a riser pipe. By ascending inside the heat transfer tube 11 and making a U-turn downward at the upper pipe 12 and repeating this, heat recovery of the exhaust gas is performed and the exhaust gas flows out from the outlet pipe 15. In the case of the example shown in
The fluid introduced into the heat transfer tube 11 from the inside of the heat transfer tube 11 first descends in the heat transfer tube 11 as a downcomer, and the adjacent lower tube 13
The upper connecting pipe 1 which makes a U-turn upward at the lower connecting pipe 16 connecting the two pipes, rises in the heat transfer pipe 11 as a rising pipe from the lower pipe 13 and connects the adjacent upper pipes 12.
By making a U-turn downward at 7 and repeating this, heat recovery of the exhaust gas is performed and the exhaust gas flows out from the outlet pipe 15.

[0007]

However, in the case of the conventional heat transfer tube 11 as described above, the upper tube 12 is required.
In addition, the number of fittings increases, and air venting is required.
In some cases, the upper connecting pipe 17 is additionally required, which has a disadvantage of increasing the weight and increasing the cost.

On the other hand, most of the above-mentioned heat transfer tube 11 support structures are usually self-supporting structures. However, as the size of the equipment increases, the self-standing heat transfer tubes 11 suffer from buckling due to their own weight. Therefore, it is considered that the heat transfer tube 11 has a suspended structure. When the heat transfer tube 11 has a hanging structure, a metal fitting is attached to the upper pipe runner 12 by welding and the metal pipe is hung.
However, there is a drawback that the welding operation of the metal fittings is required, which leads to an increase in the number of manufacturing steps.

In view of such circumstances, the present invention can obviate the need for an upper pipe, reduce the number of pipe joints, eliminate the need for air vents and an upper connecting pipe, and avoid an increase in weight and cost.
Further, it is an object of the present invention to provide a heat transfer tube support structure of an exhaust heat recovery boiler that can reliably support a heat transfer tube while simplifying the manufacturing process without welding work of fittings or the like.

[0010]

According to the present invention, a plurality of heat transfer tubes each including a riser and a downcomer are disposed in a casing through which exhaust gas flows, and a fluid introduced into the heat transfer tubes rises. The heat transfer tube support structure of the exhaust heat recovery boiler configured to perform heat recovery of the exhaust gas by repeating the process described above, and the upper end of the heat transfer tube at the place where the fluid descends from the upper part of the heat transfer tube is a joint member. And a support beam is provided in the upper part of the casing so as to extend in the width direction thereof, and the joint member is suspended and supported by a fastening member attached to the support beam. The heat transfer tube support structure of the present invention.

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

As described above, the upper end portion of the heat transfer tube at the point where the fluid descends from the upper portion at the upper portion of the heat transfer tube is directly connected by the joint member, and the support beam is provided at the upper portion inside the casing so as to extend in the width direction thereof. When the joint member is suspended and supported by the fastening member attached to the support beam, the conventional upper pipe side is unnecessary, the number of pipe joints is reduced, and the air vent and the upper connecting pipe are required. It is possible to avoid weight increase and cost increase,
Unlike the related art, it is not necessary to weld the metal fitting to the upper pipe portion, and it is possible to simplify the manufacturing.

Further, since the position of the fastening member in the height direction with respect to the support beam can be adjusted, the load on the heat transfer tube can be adjusted by adjusting the position of the fastening member in the height direction even if the dimensional accuracy of the joint member is not so strict. The support can be reliably performed.

[0014]

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

FIGS. 1 to 3 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. 7 and 8 represent the same components. This is similar to the conventional one shown in FIGS. 7 and 8, but the feature of the illustrated example is that, as shown in FIGS.
The upper end of the heat transfer tube 11 at the place where the heat transfer tube 11 descends from the upper part is directly connected by a U-bend 18 as a joint member, and a support beam 19 is provided at the upper part inside the casing 2 so as to extend in the width direction. The U-bend 18 is suspended and supported by a U-bolt 20 as a fastening member attached to the support beam 19.

A bracket 21 is provided at a required position on the upper surface of the support beam 19 extending in the width direction of the casing 2, and the bracket 21 and the bracket 23 fixed to the lower surface of the frame 22 of the casing 2 are supported by a support member. The support beam 19 is suspended from the frame 22 of the casing 2 by being connected via the support 24.

The U-bolt 20 has its both ends penetrated through a hole (not shown) in the lower flange portion 19a of the support beam 19, and is tightened with a nut 25, so that the U-bolt 20 is higher than the support beam 19. It can be attached so that the position in the vertical direction can be adjusted. The nut 25 is a double nut to prevent loosening.

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

As described above, the upper end of the heat transfer tube 11 at the point where the fluid descends from the top at the top of the heat transfer tube 11 is directly connected by the U-bend 18 as a joint member, and at the upper portion in the casing 2 in the width direction thereof. A support beam 19 is provided to extend, and U as a fastening member attached to the support beam 19 is provided.
If the U-bend 18 is suspended and supported by the bolt 20, the upper pipe 12 as in the related art is unnecessary,
In addition, the number of fittings is small, and the air vent and the upper connecting pipe 17 are required.
Is not required, and it is possible to avoid an increase in weight and an increase in cost. On the other hand, it is not necessary to weld a metal fitting to the upper pipe 12 as in the related art, and it is possible to simplify the production. Become.

Further, since the U bolt 20 can be adjusted in position in the height direction with respect to the support beam 19 by tightening the nut 25, even if the dimensional accuracy of the U bend 18 is not so strict, the height of the U bolt 20 can be reduced. The load adjustment of the heat transfer tube 11 can be reliably performed by adjusting the position in the vertical direction.
In the example shown in FIG. 3, all the U-bends 18 are suspended by the U-bolts 20 one by one. However, it is not always necessary to suspend all the U-bends 18 by the U-bolts 20. It goes without saying that the U-bend 18 at a required location may be suspended and supported by the U-bolt 20 such as every other.

In this manner, the upper pipe 12 can be eliminated, the number of pipe joints can be reduced, the air vent and the upper connecting pipe 17 can be eliminated, and an increase in weight and cost can be avoided. Thus, the heat transfer tube 11 can be reliably supported while simplifying the production.

FIGS. 4 to 6 show another embodiment of the present invention. In the drawings, the portions denoted by the same reference numerals as those in FIGS. 7 and 9 represent the same components, and The configuration is the same as the conventional one shown in FIGS. 7 and 9, but the feature of the illustrated example is that the fluid falls from the top to the bottom of the heat transfer tube 11 as shown in FIGS. 4 to 6. Transfer tube 11 in
Are directly connected by U-bends 18 and 18 'as joint members, and a support beam 19 is provided at an upper portion inside the casing 2 so as to extend in the width direction thereof, and is attached to the support beam 19 as a fastening member. The point is that the U-bend 18 is suspended and supported by the U-bolt 20.

As shown in the examples shown in FIGS. 4 to 6, the heat transfer pipe 1 at a place where the fluid descends from a rise above the heat transfer pipe 11
1 are connected directly with upper ends of U-bends 18 and 18 'as joint members, and a support beam 19 is provided in the upper part of the casing 2 so as to extend in the width direction thereof. As a fastening member attached to the support beam 19 Even if the U-bend 18 is suspended and supported by the U-bolt 20, the upper pipe runner 12 as in the related art is unnecessary, and the number of pipe joints is small.
Neither the air vent nor the upper connecting pipe 17 is required, and it is possible to avoid an increase in weight and an increase in cost. In addition, the U bolt 20 can be adjusted in position in the height direction with respect to the support beam 19 by tightening the nut 25. Therefore, even if the dimensional accuracy of the U bend 18 is not very strict, By adjusting the position of the bolt 20 in the height direction, it is possible to reliably support the load of the heat transfer tube 11. In the example shown in FIG. 6, all the U-bends 18 are suspended by the U-bolts 20 one by one.
It is needless to say that it is not necessary to suspend the U-bends 18 at the required locations, such as every other or a plurality of them, by suspending the U-bends 20 by the U-bolts 20.

Thus, in the case of the embodiment shown in FIGS. 4 to 6, similarly to the case of the embodiment shown in FIGS. The tube 17 may be unnecessary, and an increase in weight and an increase in cost can be avoided. Further, welding work of metal fittings and the like is unnecessary, and the heat transfer tube 11 can be reliably supported while simplifying the production.

Incidentally, the heat transfer tube support structure of the exhaust heat recovery boiler of the present invention is not limited to the illustrated example described above.
It goes without saying that various changes can be made without departing from the spirit of the present invention.

[0026]

As described above, according to the heat transfer tube supporting structure of the exhaust heat recovery boiler of the present invention, it is possible to eliminate the need for an upper pipe, reduce the number of pipe joints, and eliminate the need for air vents and an upper connecting pipe. In addition, it is possible to avoid an increase in weight and cost, and to eliminate the need for welding work of metal fittings and the like, while simplifying production.
An excellent effect of reliably supporting the heat transfer tube can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an example of an embodiment of the present invention.

FIG. 2 is a detailed view of a portion II in FIG.

FIG. 3 is a view taken in the direction of arrows III-III in FIG. 2;

FIG. 4 is a schematic diagram of another example of an embodiment of the present invention.

FIG. 5 is a detailed view of a portion V in FIG. 4;

FIG. 6 is a view taken in the direction of arrows VI-VI in FIG. 5;

FIG. 7 is an overall schematic configuration diagram of a general exhaust heat recovery boiler.

FIG. 8 is a schematic diagram illustrating an example of a structure of a conventional heat transfer tube in an exhaust heat recovery boiler.

FIG. 9 is a schematic diagram showing another example of the structure of the conventional heat transfer tube in the exhaust heat recovery boiler.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exhaust heat recovery boiler 2 Casing 11 Heat transfer tube 18 U bend (joint member) 18 'U bend (joint member) 19 Support beam 20 U bolt (fastening member)

Claims (1)

[Claims] A plurality of heat transfer tubes each comprising a riser tube and a downcomer tube are disposed in a casing through which the exhaust gas flows, and the fluid introduced into the heat transfer tube repeatedly rises and falls, thereby reducing exhaust gas. A heat transfer tube support structure of an exhaust heat recovery boiler configured to perform heat recovery of the heat transfer tube, wherein an upper end portion of the heat transfer tube at a point where the fluid descends from an upper portion of the heat transfer tube is directly connected by a joint member, and the inside of the casing is Arrange a support beam at the top to extend in the width direction,
A heat transfer tube support structure for an exhaust heat recovery boiler, wherein the joint member is suspended and supported by a fastening member attached to the support beam.