JPH1096505A - Pressurized fluidized bed boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce pressure loss of pressurized air in steady operation. SOLUTION: A fluidized bed boiler 20 which causes bed material 36 flow by pressurizing gas 21 from an air dispersing pipe 22 is provided inside a pressure vessel 19, a burner for activation 24 is fixed in the air dispersing pipe 22 of the fluidized bed boiler 20, an air guide pipe 28 laid around the pressure vessel 19 is connected, a damper 26 is placed in the middle of the air guide pipe 28 and a bypass pipe 31 provided with a bypass damper 33 is placed in between the outlet of the burner for activation 24 and the inlet of the damper 26 of the air guide pipe 28.

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 reducing pressure loss of pressurized air during steady operation.

[0002]

2. Description of the Related Art An example of a pressurized fluidized bed boiler 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 side by side in a plurality of stages in front and back. The air diffuser 5 includes a starter burner 6, a manually adjustable check valve 7, and an air conduit 9 extending upward and having an air intake 8 at an upper portion. The hot pressurized air 1 in the upper part of the pressure vessel 2 is taken in through this.

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

Further, an air diffuser 5 in the fluidized-bed boiler 3 is provided.
A fuel supply pipe for supplying the fuel 13 of the coal slurry and a heat transfer pipe 14 through which the boiler water is passed are provided at the upper part, and a desulfurizing material such as limestone or sand to a level corresponding to the load is provided. Mixed bed material 15 is loaded.

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 of the coal slurry is supplied to the inside of the, 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 exiting the fluidized-bed boiler 3 drives an external gas turbine (not shown) to turn a generator and drive the compressor connected to the gas turbine to enter the pressure vessel 2. Used to supply pressurized air 1.

[0017]

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

That is, a manually adjustable check valve 7 is attached to the air conduit 9, and the opening of the manually adjustable check valve 7 cannot be adjusted unless it enters the pressure vessel 2. Generally, when initially set, the aperture is kept at the opening at that time.

On the other hand, when switching from the start-up operation using the start-up burner 6 to the steady-state operation in which the start-up burner 6 is stopped,
By-pass damper 12 is driven by driving device 11 such as a motor.
, And the bypass pipe 10 is opened. However, since the manually adjustable check valve 7 is kept at a predetermined opening degree, a part of the pressurized air 1 is activated even during a steady operation. Through the burner 6.

However, since the internal structure of the start-up burner 6 is complicated, the pressure loss of a part of the pressurized air 1 passing through the start-up burner 6 becomes large, and the plant efficiency as a whole is reduced accordingly. There was a problem that would.

Also, a manually adjustable check valve 7 and a starting burner 6
Is provided in the pressure vessel 2, so that maintenance and inspection are not easy.

The present invention has been made in view of the above circumstances, and has as its object to provide a pressurized fluidized bed boiler capable of reducing the pressure loss of pressurized air during steady operation.

[0023]

According to the present invention, a pressure vessel is provided.
Is provided with a fluidized-bed boiler 20 that burns the fuel 34 with the pressurized air 21 from the diffuser 22 and causes the bed material 36 to flow, and the diffuser 22 of the fluidized-bed boiler 20 is provided.
A starter burner 24 is attached to the pressure vessel 19, an air conduit 28 routed outside the pressure vessel 19 is connected between the upper part of the pressure vessel 19 and the starter burner 24, and a damper 26 is attached in the middle of the air conduit 28. A pressurized fluidized bed boiler characterized in that a bypass pipe 31 provided with a bypass damper 33 is provided between an outlet portion 29 of the starting burner 24 and an inlet side of the damper 26 of the air conduit 28. .

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

A part of the pressurized air 18 in the pressure vessel 19
An air conduit 28 is connected to the top of the pressure vessel 19 and passes outside the pressure vessel 19.

After the starting burner 24 is ignited and the combustion is stabilized, the damper 26 provided in the air conduit 28 is fully opened, the bypass damper 33 provided in the bypass pipe 31 is closed, and all the compressed air 18 Is sent to the air diffuser 22 via a starter burner 24 provided outside the pressure vessel 19.

In this state, the fuel 37 is supplied to the starting burner 24.
And pressurized air 18 is mixed and burned.

Then, the generated combustion gas is supplied to the diffuser 22
From above, and the bed material 36 is heated.

When the bed material 36 is heated to a predetermined temperature, the supply of the fuel 37 to the starting burner 24 is stopped, the damper 26 provided in the air conduit 28 is closed, and the bed material 36 is provided in the bypass pipe 31. Bypass damper 33
Is opened so that all the pressurized air 18 bypasses the starting burner 24 and is sent to the air diffuser 22 via the bypass pipe 31.

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, when the fuel 34 of the coal slurry is supplied into the bed material 36, the supplied fuel 34 is efficiently stirred by the heat of the fluidized bed while being stirred in the fluidized bed. Become.

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

The combustion gas that has left the fluidized bed boiler 20 is
It is used to drive an external gas turbine to turn a generator and to drive a compressor connected to the gas turbine to supply pressurized air 18 into a pressure vessel 19.

As described above, according to the present invention, the damper 26
Is arranged outside the pressure vessel 19, so that the opening of the damper 26 can be easily adjusted.

Thus, during normal operation, the damper 26 is completely shut off, and the compressed air 1 is directly supplied to the diffuser 22 without passing through the inside of the combustion chamber 30 of the startup burner 24 having a complicated structure.
8 can be supplied.

Accordingly, since the pressure loss of the pressurized air 18 is reduced, the overall plant efficiency can be improved accordingly.

Further, since the damper 26 and the starting burner 24 are provided outside the pressure vessel 19, maintenance and inspection are facilitated.

[0038]

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

FIG. 1 shows an 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 includes a starter burner 24 connected to the outside of the pressure vessel 19 via a connection pipe 23, and
A damper 26 such as a butterfly valve whose opening is adjusted by a driving device 25 such as a motor is provided. The damper 26 is routed outside the pressure vessel 19, and the upper air intake 27 is connected to the upper part of the pressure vessel 19. The hot pressurized air 18 in the upper part of the pressure vessel 19 is taken in via the air conduit 28.

The combustion chamber 3 of the starting burner 24 is located between the outlet 29 of the starting 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 supply pipe for supplying coal slurry fuel 34 and a heat transfer pipe 35 through which boiler water passes are disposed above the diffuser pipe 22 in the fluidized bed boiler 20. The bed material 36 in which a desulfurizing material such as limestone, sand, or the like is mixed to a level corresponding to the level is inserted.

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.

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.

Then, the starting burner 24 is ignited, and after the combustion is stabilized, the air conduit 2 is driven by a driving device 25 such as a motor.
8, the damper 26 provided in the bypass pipe 31 is closed by a driving device 32 such as a motor, and all the pressurized air 18 is provided outside the pressure vessel 19 for starting. The air is sent to the air diffuser 22 via the burner 24.

In this state, the 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 of the 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 boiler water or the like flowing in the heat transfer tube 35 disposed inside is heated by the formed fluidized bed to generate steam.

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

As described above, according to the present invention, the damper 26
Is arranged outside the pressure vessel 19, so that the opening of the damper 26 can be easily adjusted.

Thus, the damper 26 is completely shut off during the normal operation, and the compressed air 1 is directly supplied to the air diffuser 22 without passing through the inside of the combustion chamber 30 of the starting burner 24 having a complicated structure.
8 can be supplied.

Accordingly, the pressure loss of the pressurized air 18 is reduced, so that the overall plant efficiency can be improved.

Further, since the damper 26 and the starting burner 24 are provided outside the pressure vessel 19, maintenance and inspection are facilitated.

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 gist of the present invention.

[0060]

As described above, according to the pressurized fluidized-bed boiler of the present invention, an excellent effect that the pressure loss of the pressurized air during the steady operation can be reduced can be obtained.

[Brief description of the drawings]

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

FIG. 2 is an overall schematic system diagram of a conventional example.

[Explanation of symbols]

 Reference Signs List 18 pressurized air 19 pressure vessel 20 fluidized bed boiler 21 pressurized gas (air) 22 diffuser tube 24 starter burner 26 damper 28 air conduit 29 outlet 31 bypass pipe 33 bypass damper 34 fuel 36 bed material

Claims (1)

[Claims] An air diffuser (2) is provided inside a pressure vessel (19).
A fluidized-bed boiler (20) for burning the fuel (34) with the pressurized air (21) from 2) and flowing the bed material (36) is provided. 22) A starter burner (24) is attached, and an air conduit (28) routed outside the pressure vessel (19) is connected between the upper part of the pressure vessel (19) and the starter burner (24). A damper (26) is attached in the middle of the air conduit (28), and a bypass damper (29) is provided between the outlet (29) of the starting burner (24) and the inlet side of the damper (26) of the air conduit (28). A pressurized fluidized-bed boiler comprising a bypass pipe (31) provided with 33).