JPH10122510A - Pressure fluidized bed boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to reignite a starting burner with safety. SOLUTION: A fluidized bed boiler 20 where a bed material 36 21 is arranged to flow with the application of a pressurizing gas from a diffuser tube 22, is provided inside a pressure vessel 19. A starting burner 24 is provided substantially sideways in the diffuser tube 22 of the fluidized bed boiler 20 by way of a basically horizontal connecting pipe. A drain recovery device 40 is provided near the connected area between the starting burner 24 and a connecting pipe 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a pressurized fluidized-bed boiler. More specifically, the present invention relates to a pressurized fluidized-bed boiler capable of safely re-igniting a startup burner.

[0002]

2. Description of the Related Art An example of a pressurized fluidized bed boiler currently under development will be described with reference to FIG.

[0003] Pressurized air 1 from a compressor not shown
The fluidized-bed boiler 3 is provided in the pressure vessel 2 in which the inside is pressurized by being supplied. A diffuser pipe 5 extending in the left-right direction in the figure and ejecting a pressurizing gas 4 such as air upward at a lower portion in the fluidized-bed boiler 3.
Are arranged in a plurality of stages in front and back, and the air diffuser 5 is provided with an upwardly-starting burner 6, and a manually adjustable check valve 7, and
The hot pressurized air 1 at the top of the pressure vessel 2 is taken in via an air conduit 9 which extends upward and has an air intake 8 at the top.

[0004] Incidentally, reference numeral 10 denotes a bypass pipe connected between the lower part of the air diffuser pipe 5 and the air conduit 9 for bypassing the starting burner 6, and reference numeral 12 denotes a bypass pipe provided in the bypass pipe 10.
This is a bypass damper whose opening is adjusted by a driving device 11 such as a motor.

A fuel supply pipe for supplying fuel 13 such as coal particles or coal slurry and a heat transfer pipe 1 for passing boiler water are provided above the diffuser pipe 5 in the fluidized bed boiler 3.
4 and a bed material 15 mixed with a desulfurizing material such as limestone, sand, or the like to a level reaching the upper portions of the fuel supply pipe and the heat transfer pipe 14.

Reference numeral 16 denotes a combustion chamber of the starting burner 6;
Is a starting fuel such as light oil supplied to the starting burner 6.

According to the above configuration, the following operation can be obtained.

That is, first, an external compressor (not shown) is driven to supply the pressurized air 1 into the pressure vessel 2.
Then, the pressure in the pressure vessel 2 is increased by the pressurized air 1, and a part of the pressurized air 1 enters the air conduit 9.

At the time of startup, the bypass damper 12 is throttled by a drive device 11 such as a motor so that most of the pressurized air 1 is sent to the air diffuser 5 via the startup burner 6.

In this state, the starting fuel 17 such as light oil is sent to the starting burner 6, and the starting fuel 17 and the pressurized air 1 are mixed and burned in the combustion chamber 16.

Then, the generated combustion gas is jetted upward from the air diffuser 5 to heat the bed material 15.

When the bed material 15 is heated to a predetermined temperature, the supply of the starting fuel 17 such as light oil to the starting burner 6 is stopped, and the bypass damper 12 is opened by the driving device 11 such as a motor. Pressurized air 1 bypasses the starter burner 6 and is sent to the air diffuser 5 via the bypass pipe 10.

At this time, the bed material 15 is caused to flow by the force of the injection of the pressurized air 1 to form a fluidized bed.

In this state, the bed material 15 is removed from the fuel supply pipe.
When the fuel 13 such as coal particles or coal slurry is supplied to the inside of the fluidized bed, the supplied fuel 13 is efficiently combusted by the heat of the fluidized bed while being stirred in the fluidized bed.

[0015] The thus formed fluidized bed heats the boiler water and the like flowing through the heat transfer tube 14 disposed therein to generate steam.

The combustion gas that has flowed out of the fluidized bed boiler 3 drives an external turbine (not shown) and drives the compressor connected to the turbine to supply the compressed air 1 into the pressure vessel 2. Used for

[0017]

However, the conventional pressurized fluidized bed boiler has the following problems.

That is, when starting the pressurized fluidized bed boiler,
If the ignition of the start-up burner 6 does not go well, several liters of the start-up fuel 17 is blown out from the tip of the start-up burner 6 as it is and accumulates in the start-up burner 6, but since the start-up fuel 17 is volatile, If left as it is, the starting fuel 17 is volatilized and becomes combustible gas.

If the starting burner 6 is accidentally re-ignited before the concentration of the combustible gas is sufficiently reduced, the combustible gas may ignite and burn violently.
There is a possibility that the starting burner 6 may be damaged.

An object of the present invention is to provide a pressurized fluidized-bed boiler capable of safely re-igniting a starting burner in view of the above situation.

[0021]

According to the present invention, a pressure vessel is provided.
Is provided with a fluidized-bed boiler 20 in which the bed material 36 is caused to flow by the pressurizing gas 21 from the diffuser pipe 22. The pressurized fluidized-bed boiler according to the present invention is characterized in that the burner 24 is mounted substantially horizontally and a drain recovery device 40 is provided near the connection between the starting burner 24 and the connection pipe 23.

Further, according to the present invention, a fluidized bed boiler 20 is provided inside the pressure vessel 19 so that the bed material 36 is caused to flow by the pressurizing gas 21 from the diffuser pipe 22. To the air diffuser 22
The starting burner 24 is attached slightly downward through the connection pipe 23 whose end opposite to the above is slightly bent upward, and the drain recovery device 40 is provided at the bent portion 45 of the connection pipe 23. And a pressurized fluidized-bed boiler.

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

If the ignition of the start-up burner 24 is not successful at the time of start-up, several liters of start-up fuel 37 is blown out from the end of the start-up burner 24 as it is, and
In FIG. 3, the fuel is collected near the connection portion with the start-up burner 24. However, since the start-up fuel 37 is volatile, if it is left as it is, the start-up fuel 37 is volatilized and becomes a combustible gas.

If the starter burner 24 is accidentally re-ignited before the flammable gas is released and its concentration is not sufficiently reduced, the flammable gas may ignite and burn violently. There is a possibility that the burner 24 may be damaged.
A drain recovery device 40 is provided in the vicinity of the connection with the fuel tank 4 so that the start-up fuel 37 accumulated in the connection pipe 23 can be discharged to the outside when ignition is not successful. 37 is volatilized to become a combustible gas and is prevented from igniting upon re-ignition. This makes it possible to safely re-ignite the starting burner 24.

According to the second aspect of the present invention, the drain recovery device 40 provided in the connection pipe 23 provides the same
It is possible to collect the starting fuel 37 blown out from the tip of the starting burner 24 where the ignition failed, and at the same time, to collect the starting fuel 37 blown out from the tip of the starting burner 24 where the ignition failed. By flowing down along the inclined portion of the connecting pipe 23, and collecting and collecting at a position away from the tip of the starting burner 24,
The safety at the time of re-ignition can be further improved, and more starting fuel 37 can be recovered.

[0027]

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

FIGS. 1 and 2 show a first embodiment of the present invention.

Pressurized air 1 from a compressor not shown
The fluidized-bed boiler 20 is provided in the pressure vessel 19 in which the inside is pressurized by being supplied with 8. A plurality of diffuser pipes 22 are provided at the lower part of the fluidized-bed boiler 20 so as to extend in the left-right direction in the figure and to blow out a pressurizing gas 21 such as air upward in a plurality of stages.

The air diffuser 22 has a horizontal start-up burner 24 connected through a substantially horizontal connection pipe 23 outside the pressure vessel 19, and its opening is adjusted by a drive device 25 such as a motor. An air conduit 28 which is provided with a damper 26 such as a butterfly valve at an intermediate portion, is connected to the outside of the pressure vessel 19 and has an upper air inlet 27 connected to an upper part of the pressure vessel 19, and Burner 24
The hot pressurized air 18 at the upper part of the pressure vessel 19 is taken in through the air.

The combustion chamber 3 of the starter burner 24 is provided between the outlet 29 of the starter burner 24 and the air conduit 28.
A bypass pipe 31 for bypassing the valve 0 is connected to the bypass pipe 31. The bypass pipe 31 has a bypass damper 33 whose opening is adjusted by a driving device 32 such as a motor.
Is provided.

Further, a fuel 34 such as coal particles or coal slurry is provided above the air diffuser 22 in the fluidized bed boiler 20.
And a heat transfer pipe 35 through which boiler water passes, and a fuel supply pipe and a heat transfer pipe 35.
A bed material 36 in which a desulfurizing material such as limestone or sand is mixed to a level reaching the upper part of the bed.

Reference numeral 37 denotes a starting fuel such as light oil supplied to the starting burner 24, and reference numeral 38 denotes a flow rate measuring unit provided in the air conduit 28.

In the present invention, a drain recovery device 40 is provided in the vicinity of the connection between the connection pipe 23 and the outlet 29 of the starting burner 24 (in the figure, the outlet 29 of the starting burner 24).

As shown in FIG. 2, the drain recovery device 40 is provided in a drain recovery passage 43 connected to a lower portion of the outlet 29 of the starter burner 24, and provided in the drain recovery passage 43.
And a shutoff valve 44.

Next, the operation will be described.

First, an external compressor (not shown) is driven to supply pressurized air 18 into the pressure vessel 19. Then, the pressure in the pressure vessel 19 is increased by the pressurized air 18, and a part of the pressurized air 18 is connected to the upper portion of the pressure vessel 19 and enters the air conduit 28 passing outside the pressure vessel 19. Become.

At the time of startup, the damper 26 provided on the air conduit 28 is opened by the driving device 25 such as a motor, and the bypass damper 33 provided on the bypass pipe 31 is throttled by the driving device 32 such as a motor. The pressurized air 18 is sent to the air diffuser 22 via a starter burner 24 provided outside the pressure vessel 19.

In this state, a starting fuel 37 such as light oil is sent to the starting burner 24, and the starting fuel 37 is supplied to the combustion chamber 30.
And the pressurized air 18 are mixed and burned.

Then, the generated combustion gas is supplied to the connection pipe 23.
Through the air diffuser 22, and the bed material 36 is heated.

When the bed material 36 is heated to a predetermined temperature, the supply of the starting fuel 37 such as light oil to the starting burner 24 is stopped, and the bed material 36 is provided in the air conduit 28 by the driving device 25 such as a motor. While the damper 26 is closed, the bypass pipe 31 is driven by a driving device 32 such as a motor.
Is opened, all the pressurized air 18 bypasses the starter burner 24 and bypass pipe 31
Through the air diffuser 22.

At this time, the bed material 36 is caused to flow by the force of the injection of the pressurized air 18 to form a fluidized bed.

In this state, the bed material 36 is removed from the fuel supply pipe.
When the fuel 34 such as coal particles or coal slurry is supplied to the inside of the fluidized bed, the supplied fuel 34 is efficiently combusted by the heat of the fluidized bed while being stirred in the fluidized bed.

The fluidized bed thus formed heats the boiler water or the like flowing in the heat transfer tube 35 disposed inside to generate steam.

The combustion gas exiting the fluidized bed boiler 20 is
It is used to drive an external turbine (not shown) and drive the compressor connected to the turbine to supply pressurized air 18 into the pressure vessel 19.

When the ignition of the start-up burner 24 is not successful at the start-up, several liters of the start-up fuel 3
7 is blown out from the tip of the starting burner 24 as it is,
Although the fuel is collected near the connection between the connecting pipe 23 and the outlet 29 of the starting burner 24, the starting fuel 37 is volatile. Becomes

If the starting burner 24 is accidentally re-ignited before the flammable gas is released and the concentration is not sufficiently reduced, the flammable gas may be ignited and burn violently. However, in the present invention, a drain recovery device 40 is provided in the vicinity of a connection portion between the connection pipe 23 and the outlet 29 of the startup burner 24, and the connection pipe 23 is provided in a case where ignition is not successful. Since the accumulated start-up fuel 37 can be discharged to the outside, the start-up fuel 37 is volatilized in the connection pipe 23 to become a combustible gas, and is prevented from igniting upon re-ignition. This makes it possible to safely re-ignite the starting burner 24.

More specifically, the starting fuel 37 blown out from the tip of the starting burner 24 accumulates below the outlet 29 of the starting burner 24 as shown in FIG.
Is discharged to the outside through a drain recovery path 43 connected to the lower part.

The shut-off valve 44 provided in the drain recovery passage 43 is opened for a predetermined time when the ignition of the starter burner 24 is not successful. Further, by closing the shut-off valve 44 provided in the drain recovery passage 43, it is possible to prevent the pressurized gas 21 such as the combustion gas of the starter burner 24 and the pressurized air 18 from leaking from the drain recovery passage 43 to the outside. You.

FIG. 3 shows a second embodiment of the present invention, in which a middle part of the connecting pipe 23 is bent to an angle α of about 15 degrees, and the starting burner 24 is horizontally mounted on the inclined portion 46 of the connecting pipe 23. The connection pipe 23 is provided with a slit or opening (not shown) formed at a bent portion 45 thereof, and a drain receiving member 42 is attached therearound.
Is provided with a drain recovery device 40 similar to the above.

According to the present embodiment, the start-up fuel blown out from the tip of the start-up burner 24 that failed to ignite by the drain recovery device 40 provided in the connection pipe 23, similarly to the previous embodiment. At the same time, the ignition burner 2 failed to ignite.
The starting fuel 37 blown out from the tip of the connection pipe 4 is connected to the connection pipe 23.
By flowing down along the inclined portion 46, and collecting and collecting it at a position distant from the tip of the starting burner 24, safety at the time of re-ignition can be further improved, and more starting The fuel 37 can be recovered.

Except for the above, the present embodiment has the same configuration as that of the above-described embodiment, and the same operation and effect can be obtained.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the scope of the present invention.

[0054]

As described above, according to the pressurized fluidized bed boiler of the present invention, an excellent effect that the starting burner can be safely re-ignited can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic side sectional view of a first embodiment of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a schematic side sectional view of a second embodiment of the present invention.

FIG. 4 is a schematic side sectional view of a conventional example.

[Explanation of symbols]

 Reference Signs List 19 pressure vessel 20 fluidized bed boiler 21 gas for pressurization 22 diffuser pipe 23 connection pipe 24 starter burner 36 bed material 40 drain recovery device 45 bent part

Claims (2)

[Claims] An air diffuser (2) is provided inside a pressure vessel (19).
The pressurized gas (21) from (2) allows the bed material (3)
6) A fluidized-bed boiler (20) adapted to flow is provided, and a start-up burner (24) is directed substantially sideways through a substantially horizontal connecting pipe (23) to an air diffuser (22) of the fluidized-bed boiler (20). And a starter burner (24) and a connecting pipe (2)
A pressurized fluidized bed boiler characterized in that a drain recovery device (40) is provided in the vicinity of the connection with (3). 2. An air diffuser (2) inside a pressure vessel (19).
The pressurized gas (21) from (2) allows the bed material (3)
A fluidized-bed boiler (20) adapted to flow 6) is provided. The fluidized-bed boiler (20) extends substantially horizontally to the diffuser tube (22), and the end opposite to the diffuser tube (22) faces upward. The starting burner (24) is attached slightly below via the connection pipe (23) slightly bent toward the bottom, and the drain recovery device (40) is provided at the bent portion (45) of the connection pipe (23). A pressurized fluidized bed boiler.