JP2002147704A - Structure of opening in boiler furnace wall - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of an opening in a boiler furnace wall, which is simplified and reduces the rate of stretching out from a wall surface even if the size of the opening is large, removes such troubles as falling of hammer- set refractories from the opening, wear of furnace wall tubes or the like, achieves low costs, and ensures to keep a distance between connected machinery and itself. SOLUTION: A middle header 26 is arranged in accordance with the shape of an opening 23. Furnace wall tubes 1b are connected to the header 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler furnace wall opening structure.

[0002]

2. Description of the Related Art In recent years, refuse solidified fuel (RDF: Refuse D) which has attracted attention as an effective use of municipal refuse.
Development of boiler power generation equipment using waste such as enhanced fuel (biofuel) and biomass has been advanced.

As one type of the boiler power generation equipment, there is an external circulating fluidized bed boiler. As shown in FIG. 5, the primary air A blown from an air distribution nozzle 2 disposes waste solidified fuel and the like. Furnace 1 that burns while fluidizing with bed material 3 made of sand, limestone, etc.,
A cyclone 4 connected to the upper part of the furnace 1 for collecting ash contained in exhaust gas generated by combustion in the furnace 1
An external heat exchanger 7 in which the ash collected by the cyclone 4 is introduced through an ash drop tube 5, cools the ash, and circulates the ash back to the bottom of the furnace 1 through an ash return tube 6; The exhaust gas from which the ash is collected by the cyclone 4 is introduced, and a rear heat transfer unit 10 in which a superheater 8 and a economizer 9 are disposed is provided.

On the downstream side of the economizer 9 of the rear heat transfer section 10, there is provided a gas air heater 12 for heating the air fed from the forced draft fan 11 by the heat of the exhaust gas, and the gas air heater 12 is heated by the gas air heater 12. Air is supplied as primary air A to the bottom of the furnace 1 through a primary air line 13 and a secondary air line 1 branched from the primary air line 13 is provided.
The air is supplied as secondary air B to a required position in the middle of the furnace 1 in the vertical direction through the furnace 4. Further, the air fed from the flow air blower 15 is supplied as the flow air C to the bottom of the external heat exchanger 7 through the flow air line 18. A damper 16 for adjusting the flow rate of the primary air A is provided in the middle of the primary air line 13 downstream of the branch of the secondary air line 14, and the secondary air B is provided in the middle of the secondary air line 14. A damper 17 for adjusting the flow rate is provided.

The external heat exchanger 7 is provided with a flow air C
To form a wind box 21 for blowing air upward from the air distribution nozzle 20, and to generate superheated steam by heat exchange with circulating ash in the seal box 19 above the air distribution nozzle 20 and introduce the superheated steam into the steam turbine. Of the final superheater 22 is disposed. or,
The external heat exchanger 7 considers that the pressure in the lower part of the furnace 1 is generally higher than the pressure in the lower part of the cyclone 4, and in this state, the exhaust gas in the furnace 1 reduces the exhaust gas in the lower part of the cyclone 4. To prevent it from flowing into the ash drop tube 5 side,
The ash separated in the cyclone 4 is formed in a so-called siphon-like shape so that the ash can be reliably flowed down into the furnace 1 and returned.

In the external circulating fluidized-bed boiler as a boiler power generation facility as described above, air pressure-fed from a forced draft fan 11 is heated by a gas air heater 12, and primary air flows to a bottom of the furnace 1 through a primary air line 13. A is supplied as A, and is supplied as secondary air B to a required position in an intermediate portion in the vertical direction of the furnace 1 through a secondary air line 14 branched from the primary air line 13, and is further pressure-fed from a flowing air blower 15. Air is supplied to the bottom of the external heat exchanger 7 via the flow air line 18 as the flow air C. In this state, waste such as refuse-solidified fuel is placed on the air distribution nozzle 2 of the furnace 1. The waste is burned while being fluidized together with the bed material 3 by the primary air A blown out from the air dispersion nozzle 2.

Exhaust gas generated by the burning of waste in the furnace 1 is blown up together with the ash and introduced into the cyclone 4, where the ash is collected and the ash collected by the cyclone 4. Is introduced into an external heat exchanger 7 as an ash recirculation device from an ash falling pipe 5 connected to the lower part of the cyclone 4, and after the heat is removed and cooled in the external heat exchanger 7, the ash return pipe 6 is removed. The gas is returned to the bottom of the furnace 1 through the furnace and circulated.

The exhaust gas from which the ash has been separated by the cyclone 4 is led to a rear heat transfer section 10, where heat is recovered in a superheater 8 and a economizer 9 of the rear heat transfer section 10, and further, in a gas air heater 12. After being collected, it is discharged from the chimney to the atmosphere via a dust collector (not shown).

On the other hand, the boiler feed water is heated by the exhaust gas in the economizer 9, flows through the steam drum (not shown), flows through the boiler furnace wall 1a of the furnace 1, returns to the steam drum again, becomes saturated steam, and is overheated. The superheated steam introduced into the heater 8 and superheated by the exhaust gas, and superheated in the superheater 8,
The superheated steam guided to the final superheater 22 and further superheated by the circulating ash, and superheated in the final superheater 22, is introduced into a steam turbine to generate power.

The boiler furnace wall 1a of the furnace 1
As shown in FIGS. 6 to 8, the furnace wall tubes 1b arranged side by side at a required interval are connected by fins 1c, and the boiler furnace wall 1a is provided with exhaust gas to the cyclone 4. Opening 23 for guiding the
Is formed by bending a plurality of furnace wall tubes 1b and placing a refractory 24 therein, so that an inlet duct 4a of the cyclone 4 is connected via an expansion 25.

[0011]

However, as described above, when the openings 23 are formed by bending the plurality of furnace wall tubes 1b, the number of bent furnace wall tubes 1b increases as the openings 23 become larger. However, the structure is complicated and the amount of protrusion L1 'from the wall surface increases, the refractory 24 cast into the opening 23 falls off, the furnace wall tube 1b is exposed, and wear and the like caused by passing gas are reduced. This has the disadvantage of causing troubles and increasing costs.

When the position of the cyclone 4 as a connecting device with respect to the furnace 1 is determined, the expansion 25 from the wall becomes larger as the expansion amount L1 'from the wall increases.
Length L2 'becomes short, and there is a problem that there is no room for absorbing a difference in thermal deformation.

In view of such circumstances, the present invention can simplify the structure and reduce the amount of protrusion from the wall even if the opening is large, and the refractory dropped into the opening can fall off. It is an object of the present invention to provide an opening structure of a boiler furnace wall which can avoid troubles such as abrasion of a furnace wall tube and the like, can reduce costs, and can secure an interval with a connected device.

[0014]

SUMMARY OF THE INVENTION The present invention relates to an opening structure for a boiler furnace wall in which fins are connected between furnace wall tubes which are arranged side by side at a required interval and are adapted to the shape of the opening. And a furnace wall pipe is connected to the intermediate pipe near the intermediate pipe.

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

An intermediate pipe is disposed in accordance with the shape of the opening,
When the furnace wall tube is connected to the intermediate pipe, even if the opening is large, the furnace wall tube does not have to be bent intricately, the structure is simplified, and the amount of protrusion from the wall does not increase, and the opening is large. The refractory to be cast hardly falls off, and the problem that the furnace wall tube at the opening is exposed and worn by the passing gas is avoided, which is advantageous in cost.

Further, when a connection device such as a cyclone is connected to the opening through an expansion or the like, the length of the expansion or the like can be increased by an amount corresponding to a reduced amount of overhang from the wall surface, resulting in a thermal deformation. In absorbing the difference between the two, there is a margin, which is effective.

[0018]

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

FIGS. 1 to 4 show an embodiment of the present invention. In the drawings, the portions denoted by the same reference numerals as those in FIGS. 5 to 8 represent the same components. This embodiment is the same as the conventional one shown in FIGS. 5 to 8, but is characterized in that an intermediate pipe 26 is arranged according to the shape of the opening 23 as shown in FIGS. 1 to 4. The point is that the furnace wall pipe 1b is connected to the intermediate pipe 26.

In the case of the illustrated example, since the opening 23 is rectangular, the intermediate pipe 26 is formed in a rectangular shape by combining a straight pipe and an elbow. The furnace wall tube 1b is connected to the portion corresponding to the upper and lower sides of the side 26 by bending it at a substantially right angle.

As shown in FIGS. 1 and 3, portions corresponding to the left and right sides of the rectangular intermediate pipe 26 are formed as shown in FIGS.
Since the furnace wall tube 1b has a shape extending in parallel, there is a skin casing 27 between them, as shown in FIGS.
Is provided to maintain airtightness.

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

As described above, the intermediate pipe 26 is disposed in accordance with the shape of the opening 23, and the furnace wall pipe 1b is connected to the intermediate pipe 26. Thus, even if the opening 23 is large, the furnace wall pipe 1b Is not complicatedly bent, the structure is simplified, the amount of protrusion L1 from the wall surface is not increased, and the refractory 24 cast into the opening 23 is less likely to fall off. Troubles such as abrasion due to the gas passing through the exposed portion 1b can be avoided, which is advantageous in cost.

Further, even if the position of the cyclone 4 as a connecting device with respect to the furnace 1 is determined, the length L2 of the expansion 25 can be increased by the amount of the protrusion L1 from the wall, and the thermal deformation can be achieved. In absorbing the difference between the two, there is a margin, which is effective.

Thus, even if the opening 23 is large,
The structure can be simplified and the amount of protrusion L1 from the wall surface can be reduced, and the refractory 2 cast into the opening 23 can be provided.
4 can be avoided and trouble such as wear of the furnace wall tube 1b can be avoided.
The cost can be reduced, and the space with the cyclone 4 as the connection device can be secured.

The opening structure of the boiler furnace wall of the present invention is as follows.
The present invention is not limited to the above illustrated example, and is not limited to the external circulating fluidized bed boiler, and can be applied to various boilers and the like, and it is possible to make various changes without departing from the gist of the present invention. Of course.

[0027]

As described above, according to the opening structure of the boiler furnace wall of the present invention, even if the opening is large, the structure can be simplified and the amount of protrusion from the wall surface can be reduced. In addition, it is possible to avoid troubles such as dropping of a refractory cast into the opening and abrasion of a furnace wall tube, thereby achieving cost reduction, and an excellent effect of securing a space between connected equipment.

[Brief description of the drawings]

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

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

FIG. 3 is a view taken in the direction of arrows III-III in FIG. 1;

FIG. 4 is a view taken in the direction of arrows IV-IV in FIG. 1;

FIG. 5 is an overall schematic configuration diagram of an example of an external circulating fluidized bed boiler.

6 is a front view of a conventional example, and is a view corresponding to the view taken along the line VI-VI in FIG.

FIG. 7 is a view taken along the line VII-VII in FIG. 6;

8 is a view taken in the direction of arrows VIII-VIII in FIG. 6;

[Explanation of symbols]

 1a Boiler furnace wall 1b Furnace wall tube 1c Fin 23 Opening 24 Refractory 25 Expansion 26 Intermediate pipe

Claims (1)

[Claims] 1. An opening structure of a boiler furnace wall in which furnace wall tubes arranged side by side at required intervals are connected by fins, wherein an intermediate pipe is arranged in accordance with the shape of the opening. An opening structure of a boiler furnace wall, wherein a furnace wall tube is connected to the intermediate tube.