JP3812055B2 - Burner device for startup of pressurized fluidized bed boiler - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a burner device for starting a pressurized fluidized bed boiler. More particularly, the present invention relates to a start-up burner device for a pressurized fluidized bed boiler that can safely re-ignite the start-up burner.
[0002]
[Prior art]
An example of a pressurized fluidized bed boiler currently under development will be described with reference to FIG.
[0003]
A fluidized bed boiler 3 is provided in a pressure vessel 2 whose inside is pressurized by supplying pressurized air A from a compressor (not shown) through a pressurized air pipe 1.
[0004]
In the lower part of the fluidized bed boiler 3, a plurality of diffuser tubes 5 are arranged in parallel in the front-rear direction so as to extend in the left-right direction in FIG. 2 and to eject a pressurizing gas 4 such as air upward.
[0005]
Furthermore, a fuel supply pipe 6 for supplying fuel such as coal particles or coal slurry and a heat transfer pipe 7 through which boiler water is passed are disposed above the air diffusion pipe 5 in the fluidized bed boiler 3. A bed material 8 in which a desulfurizing material such as limestone, sand or the like is mixed up to a level reaching the upper portion of the fuel supply pipe 6 and the heat transfer pipe 7 is inserted.
[0006]
The air diffuser 5 is connected to an activation burner 10 provided sideways via a substantially horizontal communication tube 9.
[0007]
The starter burner 10 includes a burner casing 11 having a front end connected to the communication pipe 9. A front exhaust pipe 12 is attached to the front end of the burner casing 11 and is made of a porous material. A combustion cylinder 13 is provided. Light oil 15 is supplied to the center of the rear end of the combustion cylinder 13 by an on-off valve 17, and fuel is supplied into the combustion cylinder 13 by compressed air 19 supplied by the on-off valve 18. A burner main body 20 adapted to be ejected is provided.
[0008]
Further, the burner casing 11 is provided with a pressurized air introduction port 21 for introducing the compressed air A for combustion to the outer periphery of the combustion cylinder 13, and the outer periphery of the combustion cylinder 13 and the partition wall 12a. Is provided with a bypass air introduction port 22 for bypassing and introducing the pressurized air A to the outer periphery of the front exhaust cylinder 12 partitioned by.
[0009]
The starting burner 10 is provided with an ignition device 23 that can be inserted and removed so that the tip extends through the burner casing 11 and extends into the combustion cylinder 13, and the combustion cylinder 13 is monitored from the outside for ignition. A flame detector 24 to be confirmed is attached to the burner casing 11.
[0010]
The pressurized air inlet 21 is connected to the pressure vessel 2 via an air conduit 25, and a butterfly valve whose opening is adjusted by a driving device 26 such as a motor in the middle of the air conduit 25. The damper 27 is provided.
[0011]
Further, a bypass air conduit 28 is connected between the upstream position of the damper 27 in the air conduit 25 and the bypass air introduction port 22, and a drive device 29 such as a motor is provided in the middle of the bypass air conduit 28. A bypass damper 30 such as a butterfly valve whose opening degree is adjusted is provided. Further, a flow meter 31 is provided upstream of the connection position of the bypass air conduit 28 in the air conduit 25.
[0012]
In order to drive the fluidized bed boiler 3, first, an external compressor (not shown) is driven to supply the pressurized air A into the pressure vessel 2. Then, the pressure in the pressure vessel 2 is increased by the pressurized air A, and a part of the pressurized air A enters the air conduit 25 connected to the upper portion of the pressure vessel 2.
[0013]
Then, the damper 27 is opened by the driving device 26 and the bypass damper 30 is opened by the driving device 29, so that most of the pressurized air A is sent to the diffuser tube 5 through the activation burner 10 and the communication tube 9. To.
[0014]
In this state, the opening / closing valve 17 and the opening / closing valve are adjusted in a state in which the opening degree of the damper 27 and the bypass damper 30 is adjusted to adjust the pressurized air A supplied from the pressurized air inlet 21 to the outer periphery of the combustion cylinder 13. The gas oil 15 is burned in the combustion cylinder 13 by opening 18 and supplying the burner body 20 with the light oil 15 and compressed air 19 for starting ignition and injecting them, and igniting them with the ignition device 23. At this time, the flame detector 24 confirms that the light oil 15 has been reliably burned.
[0015]
When the combustion of the light oil 15 is confirmed, the supply amount of the light oil 15 is increased, and at the same time, the flow rate of the pressurized air A supplied from the compressed air introduction port 21 to the combustion cylinder 13 is increased. The opening degree is increased and the opening degree of the bypass damper 30 is controlled to be reduced.
[0016]
The high-temperature exhaust gas combusted in the combustion cylinder 13 of the activation burner 10 is guided to the diffuser pipe 5 through the front exhaust cylinder 12 and the communication pipe 9 and is jetted upward from the diffuser pipe 5 to form the bed material. 8 is heated.
[0017]
As described above, when the bed material 8 is heated to a predetermined temperature, the supply of the light oil 15 to the activation burner 10 is stopped, the bypass damper 30 is opened, and the damper 27 is closed, whereby all the pressurized air A is removed. The air is sent to the diffuser pipe 5 through the bypass air inlet 22 and the communication pipe 9. At this time, a large amount of pressurized air A is supplied to the heated bed material 8 and the pressurized air A expands by rapid heating, whereby the bed material 8 flows (bubbling) to form a fluidized bed. The
[0018]
In this state, when fuel such as coal particles or coal slurry is supplied from the fuel supply pipe 6 into the bed material 8, the supplied fuel is efficiently burned by the heat of the fluidized bed while being stirred in the fluidized bed. The Rukoto. The fluidized bed formed as described above heats the boiler water and the like flowing in the heat transfer tubes 7 disposed therein, thereby generating steam. On the other hand, the combustion gas exiting the fluidized bed boiler 3 drives an external turbine (not shown), drives the compressor connected to the turbine, and supplies pressurized air A into the pressure vessel 2. .
[0019]
[Problems to be solved by the invention]
However, when the pressurized fluidized bed boiler is started as described above, there has been a case where ignition to the light oil 15 supplied to the starting burner 10 results in misfire.
[0020]
That is, the ratio of the amount of light oil 15 supplied to the burner body 20 and the pressurized air A introduced from the pressurized air inlet 21 is deviated from the optimum state, or the spark condition of the ignition device 23 is bad. If the jet flow of the light oil 15 ejected from the burner body 20 and the position of the spark of the ignition device 23 are misaligned, the ignition may not be performed.
[0021]
In this way, when the ignition of the light oil 15 is not ignited, it can be known by the flame detector 24 that the ignition has not been performed, so the on-off valve 17 is immediately closed and the supply of the light oil 15 is stopped. At that time, several liters of light oil 15 has already been blown into the combustion cylinder 13 from the tip of the burner body 20, and the discharged light oil 15 passes through the combustion cylinder 13 and accumulates at the bottom of the burner casing 11. Since the light oil 15 ′ accumulated at the bottom is volatile, if it is left as it is, it will be vaporized and the combustible gas will fill the inside of the starter burner 10.
[0022]
If the starter burner 10 is accidentally reignited before the concentration of the combustible gas is sufficiently reduced, the combustible gas may be ignited and burnt vigorously, resulting in damage to the starter burner 10. There is a fear.
[0023]
SUMMARY OF THE INVENTION In view of the above circumstances, the present invention aims to provide a startup burner device for a pressurized fluidized bed boiler that can be safely re-ignited even if the startup burner is not ignited. is there.
[0024]
[Means for Solving the Problems]
The invention according to claim 1 includes a burner casing having a burner casing having a front end connected to a communication pipe connected to a diffuser pipe of a fluidized bed boiler, and a front exhaust pipe attached to the front end inside the burner casing. A burner body that supplies light oil to the rear end portion of the combustion cylinder and jets fuel into the combustion cylinder by compressed air, and the burner casing is provided with pressurized air around the outer periphery of the combustion cylinder. A pressurized burner apparatus for starting a pressurized fluidized bed boiler having a pressurized air introduction port for introduction and a bypass air introduction port for introducing pressurized air to the outer periphery of the front exhaust pipe, The present invention relates to a starter burner device for a pressurized fluidized bed boiler, characterized in that an inert gas introduction pipe provided with an inert gas on-off valve is connected to an outer position of the combustion cylinder.
[0025]
The invention described in claim 2 relates to the burner device for starting a pressurized fluidized bed boiler according to claim 1, wherein the inert gas introduction pipe is provided with a heater.
[0026]
According to a third aspect of the present invention, a carbon monoxide concentration detector for detecting the carbon monoxide concentration in the gas is provided in the path between the combustion cylinder and the air diffuser, and the inert gas is opened and closed by the input of a non-ignition signal. 2. A controller for opening the valve and closing the inert gas on / off valve when the detected concentration of carbon monoxide by the carbon monoxide concentration detector becomes lower than a set value. This relates to a starter burner device for a pressurized fluidized bed boiler according to 2.
[0027]
In the first aspect of the present invention, when the pressurized fluidized bed boiler is started, even if the light oil supplied to the starting burner is not ignited and the light oil accumulates at the inner bottom of the burner casing, Since the light oil accumulated in the inner bottom is removed by supplying inert gas, the vaporized combustible gas will burn suddenly when light oil is injected again from the burner body and then ignited. Can be eliminated, and safety at the time of re-ignition can be improved.
[0028]
In the second aspect of the invention, when the inert gas from the inert gas supply source is supplied to the start-up burner, the inert gas is heated by the heater, so that it accumulates at the inner bottom of the burner casing. The time for removing the accumulated light oil can be shortened by promoting the vaporization of the light oil.
[0029]
In the invention according to claim 3, the carbon monoxide concentration detector automatically detects that the inert gas on-off valve is opened by the input of the non-ignition signal and the removal of the light oil accumulated in the inner bottom portion of the burner casing is completed. It is equipped with a controller that detects and shuts off the inert gas on-off valve, so the time to restart the start burner can be shortened and the amount of inert gas used is reduced. it can.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0031]
FIG. 1 shows an embodiment of the present invention, and shows a case where nitrogen gas is used as an inert gas. In the starter burner 10 provided in the pressurized fluidized bed boiler, a nitrogen gas on-off valve (inert gas on-off valve) is provided at an upper position outside the combustion cylinder 13 in the burner casing 11 constituting the starter burner 10. 32 is connected to a nitrogen gas introduction pipe (inert gas introduction pipe) 33, and the nitrogen gas introduction pipe 33 is connected to a nitrogen gas supply source (inert gas supply source) 34. The nitrogen gas (inert gas) 35 is supplied to the activation burner 10 by opening and closing a nitrogen gas opening / closing valve 32 provided in the nitrogen gas introduction pipe 33.
[0032]
The nitrogen gas introduction pipe 33 is provided with a heater 36 that heats the nitrogen gas 35 from the nitrogen gas supply source 34.
[0033]
The nitrogen gas supply source 34 may be a nitrogen gas cylinder or the like, and in a pressurized fluidized bed boiler as described above, the fuel in the fuel supply pipe 6 is generally purged when the fluidized bed boiler 3 is stopped. Methods such as replacement with gas or embedding a nitrogen gas supply pipe in a coal bunker to prevent spontaneous combustion of coal are being implemented. Therefore, the nitrogen gas manufactured by the nitrogen gas manufacturing apparatus can be used.
[0034]
In addition to the nitrogen gas described above, exhaust gas from other driven boilers can be used as the inert gas.
[0035]
In the configuration shown in FIG. 1, when starting the pressurized fluidized bed boiler, if the light oil 15 supplied to the starter burner 10 is not ignited, it is not ignited by the flame detector 24. When the on / off valve 17 is immediately closed, the supply of the light oil 15 is stopped.
[0036]
At this time, however, several liters of light oil 15 has already been blown into the combustion cylinder 13 from the tip of the burner body 20 and accumulated at the bottom of the burner casing 11, so Based on the ignition, the nitrogen gas on-off valve 32 is opened to supply the nitrogen gas 35 of the nitrogen gas supply source 34 to the outer periphery of the combustion cylinder 13. By supplying the nitrogen gas 35 for a predetermined time, the light oil 15 ′ accumulated at the bottom of the burner casing 11 is evaporated and removed from the bottom of the burner casing 11. When all the light oil 15 ′ accumulated in the burner casing 11 can be removed, the nitrogen gas on / off valve 32 is closed and the supply of the nitrogen gas 35 is stopped.
[0037]
As described above, when the pressurized fluidized bed boiler is started, even if the light oil 15 supplied to the starting burner 10 is not ignited and the light oil 15 ′ is accumulated in the inner bottom portion of the burner casing 11, Since the light oil 15 ′ accumulated as described above is removed by supplying the nitrogen gas 35, when the light oil 15 is again injected from the burner body 20 and ignition is performed again, the vaporized combustible gas rapidly increases. There is no such thing as burning, and safety during reignition can be improved.
[0038]
Further, when the nitrogen gas 35 from the nitrogen gas supply source 34 is supplied to the activation burner 10, the vaporization of the light oil 15 ′ accumulated at the bottom of the burner casing 11 is promoted by heating the nitrogen gas 35 by the heater 36. The time for removing the accumulated light oil 15 ′ can be shortened.
[0039]
Further, in FIG. 1, a device for automatically removing light oil 15 ′ accumulated in the inner bottom portion of the burner casing 11 due to non-ignition of the light oil 15 is provided.
[0040]
That is, a carbon monoxide concentration detector 37 that detects the concentration of carbon monoxide in the gas passing through the inside of the communication pipe 9 is provided in the path between the combustion cylinder 13 and the diffuser pipe 5, for example, the communication pipe 9. The controller 40 is provided with a controller 40 for inputting a detected concentration 38 of carbon monoxide by the carbon monoxide concentration detector 37 and a non-ignition signal 39 obtained by the flame detector 24. When the non-ignition signal 39 is input, the nitrogen gas on-off valve 32 is opened to remove the light oil 15 ′ accumulated in the inner bottom of the burner casing 11, and the monoxide from the carbon monoxide concentration detector 37 is removed. The nitrogen gas on-off valve 32 is closed when the detected carbon concentration 38 becomes lower than the set value.
[0041]
According to the above configuration, when starting the pressurized fluidized bed boiler, if the flame detector 24 detects that the light oil 15 supplied to the starting burner 10 has not been ignited, the ignition is not ignited. When the signal 39 is input to the controller 40, the controller 40 operates to open the nitrogen gas on / off valve 32, whereby the nitrogen gas 35 of the nitrogen gas supply source 34 is supplied to the activation burner 10.
[0042]
By supplying the nitrogen gas 35, the light oil 15 ′ accumulated in the inner bottom portion of the burner casing 11 is vaporized to become combustible gas (carbon monoxide), and the carbon monoxide flows through the communication pipe 9 together with the nitrogen gas 35, The concentration of carbon monoxide in the gas 35 is detected by a carbon monoxide concentration detector 37. At this time, the detected concentration 38 of carbon monoxide shows a high value.
[0043]
When the light oil 15 ′ accumulated at the bottom of the burner casing 11 is not reduced by vaporization, the carbon monoxide detection concentration 38 by the carbon monoxide concentration detector 37 is rapidly reduced, so that the detection of the carbon monoxide is performed. When the concentration 38 becomes lower than the set value, the controller 40 operates so as to automatically close the nitrogen gas on-off valve 32.
[0044]
Therefore, according to the above, since it is automatically detected that the removal of the light oil 15 ′ accumulated in the inner bottom portion of the burner casing 11 is finished and the supply of the nitrogen gas 35 is stopped, the activation burner 10 is restarted. Can be shortened, and the amount of nitrogen gas 35 used can also be reduced.
[0045]
It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.
[0046]
【The invention's effect】
According to the first aspect of the present invention, when the pressurized fluidized bed boiler is started, even if the light oil supplied to the starting burner is not ignited and the light oil is accumulated in the inner bottom portion of the burner casing, Since the light oil accumulated in the inner bottom of the burner casing is removed by supplying inert gas, the vaporized combustible gas burns rapidly when ignition is performed by injecting light oil again from the burner body. There is no such a thing, and there is an effect that the safety at the time of re-ignition can be improved.
[0047]
According to the second aspect of the present invention, when the inert gas of the inert gas supply source is supplied to the starting burner, the inert gas is heated by the heater. This has the effect of shortening the time for removing the accumulated light oil by promoting the vaporization of the accumulated light oil.
[0048]
According to the third aspect of the present invention, the carbon monoxide concentration detector detects that the inert gas on-off valve is opened by the input of the non-ignition signal and the removal of the light oil accumulated in the inner bottom portion of the burner casing is completed. Since it has a controller that automatically detects and closes the inert gas on-off valve, it can reduce the time to restart the start burner and reduce the amount of nitrogen gas used. There is an effect that can be reduced.
[Brief description of the drawings]
FIG. 1 is a schematic sectional side view of an embodiment of the present invention.
FIG. 2 is a schematic sectional side view showing an example of a starting burner device in a conventional pressurized fluidized bed boiler.
[Explanation of symbols]
3 Fluidized bed boiler 5 Aeration pipe 9 Communication pipe 11 Burner casing 12 Front exhaust cylinder 13 Combustion cylinder 15 Light oil 19 Compressed air 20 Burner body 21 Pressurized air inlet 22 Bypass air inlet 32 Nitrogen gas on-off valve (inert gas on / off valve) valve)
33 Nitrogen gas introduction pipe (inert gas introduction pipe)
36 Heater 37 Carbon monoxide concentration detector 38 Detection concentration 39 Non-ignition signal 40 Controller A Pressurized air

Claims (3)

A burner casing having a front end connected to a communication pipe connected to a diffuser pipe of a fluidized bed boiler, a combustion cylinder having a front exhaust pipe attached to the front end is provided inside the burner casing, and a rear end of the combustion cylinder A burner body that is supplied with light oil and injects fuel into the combustion cylinder by compressed air, and the burner casing has a pressurized air inlet for introducing pressurized air to the outer periphery of the combustion cylinder And a pressurized fluidized bed boiler activation device having a bypass air introduction port for introducing pressurized air to the outer periphery of the front exhaust cylinder, and is inactive at a position outside the combustion cylinder in the burner casing. A burner device for starting a pressurized fluidized bed boiler, wherein an inert gas introduction pipe having a gas on-off valve is connected. The starter burner device for a pressurized fluidized bed boiler according to claim 1, wherein the inert gas introduction pipe is provided with a heater. A carbon monoxide concentration detector that detects the carbon monoxide concentration in the gas is installed in the path between the combustion cylinder and the diffuser pipe, and the inert gas on-off valve is opened by the input of the non-ignition signal. The pressurized fluidized bed boiler according to claim 1 or 2, further comprising a controller for closing the inert gas on-off valve when the detected concentration of carbon monoxide by the concentration detector becomes a set value or less. Starting burner device.

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