JP3738487B2 - Combustion air control device for combination burner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combustion air control device for a combination burner.
[0002]
[Prior art]
Generally, as shown in FIG. 3, a conventional burner used in a boiler or the like is provided with a single type of fuel burner 3 in a burner body 2 provided so as to open to one burner throat 1, and the fuel burner. A burner valve 5 is provided in the middle of the fuel supply pipe 4 for supplying fuel to the fuel, a combustion air adjusting damper 7 is provided in the middle of the combustion air supply pipe 6 for supplying combustion air to the burner body 2, and a boiler A controller 8 is provided that obtains and outputs a basic opening degree command 9 of the combustion air adjustment damper 7 based on a load request command (MWD).
[0003]
In the case of a normal boiler, the burner throat 1 is formed in a plurality of rows in the horizontal direction of the front and rear furnace walls, and in a plurality of stages in the vertical direction of the front and rear furnace walls. It has come to be.
[0004]
As shown in FIG. 4, the controller 8 has a function generator 10 that obtains and outputs a basic opening degree command 9 of the combustion air adjustment damper 7 based on the load request command.
[0005]
A function as shown in FIG. 5 is input to the function generator 10, and the function is approximately proportional to the increase / decrease in the load request command, and the basic opening command of the combustion air adjustment damper 7. 9 is increased or decreased.
[0006]
In the conventional burner as described above, the basic opening degree command 9 of the combustion air adjustment damper 7 is obtained and outputted from the function generator 10 of the controller 8 based on the load request instruction of the boiler. Thus, the opening degree of the combustion air adjusting damper 7 is adjusted, and an appropriate amount of combustion air is supplied from the combustion air supply pipe 6 to the burner body 2.
[0007]
[Problems to be solved by the invention]
As described above, when there is one kind of fuel combusted in one burner throat 1, the combustion air adjustment damper 7 is based on the basic opening degree command 9 obtained by the function generator 10 of the controller 8 as in the prior art. However, it is possible to optimize the amount of combustion air supplied from the combustion air supply pipe 6 to the burner body 2 even if the opening degree is simply adjusted.
[0008]
However, in recent years, a burner body 2 provided so as to open to one burner throat 1 is not provided with a single type of fuel burner 3 but a fuel burner that burns a plurality of types of fuels such as gas and oil. A so-called combination burner has been developed in which a plurality of types of fuels are disposed in one burner throat 1 individually or in appropriate combination and simultaneously burned. In the case of such a combination burner, a conventional controller is used. If the opening degree of the combustion air adjustment damper 7 is simply adjusted by the basic opening degree command 9 obtained by the function generator 10 of 8, the combustion air supply pipe 6 does not necessarily provide an appropriate amount of combustion air. However, when the amount of combustion air is excessive, combustion may become unstable, for example, NOx may increase.
[0009]
In view of such circumstances, the present invention is intended to provide a combustion air control device for a combination burner that can supply combustion air in an amount suitable for combustion of a plurality of types of fuel and can always stabilize the combustion. Is.
[0010]
[Means for Solving the Problems]
In the present invention, a plurality of types of fuel burners are provided in a burner body provided to open to one burner throat, and a burner valve is provided in the middle of a fuel supply pipe for supplying different fuels to each fuel burner, A combustion air control device for a combination burner in which a combustion air adjustment damper is provided in the middle of a combustion air supply pipe for supplying combustion air to the burner body,
A function generator that calculates and outputs the basic opening command of the combustion air adjustment damper based on the load request command, and appropriate depending on the open / close state of each burner valve based on the open / close signal of each burner valve A gain selector that outputs a large gain as a signal, and a corrected opening command of the combustion air adjustment damper by multiplying the basic opening command output from the function generator by the gain signal output from the gain selector The present invention relates to a combustion air control device for a combination burner, characterized in that it includes a controller having a multiplier for outputting the.
[0011]
According to the above means, the following operation can be obtained.
[0012]
During operation, a basic opening degree command for the combustion air adjustment damper is obtained in the function generator of the controller based on the load request command and output to the multiplier.
[0013]
Here, when the burner valves are all closed, the gain corresponding to the fully closed preset in the gain selector is output as a signal to the multiplier, and the multiplier A basic opening command output from the generator is multiplied by a gain signal output from the gain selector to output a corrected opening command of the combustion air adjustment damper. The opening of the adjustment damper is adjusted, an appropriate amount of combustion air is supplied from the combustion air supply pipe to the burner body, and the combustion air is not for fuel combustion but for cooling the burner body and the fuel burner. Will be supplied as
[0014]
In addition, when only one of the burner valves is individually opened, the individually corresponding gain preset in the gain selector is output as a signal to the multiplier, and in the multiplier, the function A basic opening command output from the generator is multiplied by a gain signal output from the gain selector to output a corrected opening command of the combustion air adjustment damper. The opening of the adjustment damper is adjusted, and an appropriate amount of combustion air necessary for combustion of the supplied individual fuel is supplied from the combustion air supply pipe to the burner body.
[0015]
Furthermore, when a plurality of types of fuel burner valves are combined and opened, a gain corresponding to a combination preset in a gain selector is output to the multiplier as a signal. The basic opening degree command output from the function generator is multiplied by the gain signal output from the gain selector to output a corrected opening degree command for the combustion air adjustment damper. The opening degree of the combustion air adjustment damper is adjusted, and an appropriate amount of combustion air necessary for simultaneous combustion of a plurality of types of combined fuel is supplied from the combustion air supply pipe to the burner body.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0017]
1 and 2 show an example of an embodiment for carrying out the present invention. In the figure, the parts denoted by the same reference numerals as those in FIGS. 3 to 5 represent the same thing and open to one burner throat 1. A plurality of types (two types in the illustrated example) of fuel burners 3a and 3b are disposed in the burner body 2 provided in this manner, and a fuel supply pipe 4a for supplying different fuels A and B to the fuel burners 3a and 3b, respectively. , 4b are provided with burner valves 5a, 5b.
[0018]
Further, the controller 8 outputs a proper gain as a signal 26 according to the open / closed state of each burner valve 5a, 5b, which is fully closed, individually or combined, based on the open / close signals 11a, 11b of the burner valves 5a, 5b. The gain selector 12 and the basic opening command 9 output from the function generator 10 are multiplied by the gain signal 26 output from the gain selector 12 to multiply the corrected opening command 9 of the combustion air adjustment damper 7. And a multiplier 13 for outputting '.
[0019]
As shown in FIG. 2, the gain selector 12 includes a fully closed gain setting unit 15 for presetting the gain 14 when all the burner valves 5a and 5b are closed, and only the fuel A burner valve 5a is opened. When the fuel A burner valve 5a is open, the gain 16 from the individual gain setter 17 is output as a signal 18 while the fuel A burner valve 5a is open. When the burner valve 5a is closed, a switching relay 19 that outputs the gain 14 from the fully closed gain setter 15 as a signal 18 and a gain 20 when only the fuel B burner valve 5b is open are set in advance. When the individual gain setting unit 21 and the burner valve 5b for the fuel B are open, the gain 20 from the individual gain setting unit 21 is output as a signal 22, while the burner for the fuel B is output. When the switch 5b is closed, the gain 24 when the switch relay 23 that outputs the signal 18 from the switch relay 19 as the signal 22 and the burner valves 5a and 5b of the fuels A and B are opened in combination is set in advance. When the combination gain setting unit 25 to be set and the burner valves 5a and 5b for the fuels A and B are open, the gain 24 from the combination gain setting unit 25 is output as a signal 26, while the burners for the fuels A and B are output. When the valves 5a and 5b are closed, a switching relay 27 that outputs the signal 22 from the switching relay 23 as a signal 26 is provided.
[0020]
Next, the operation of the illustrated example will be described.
[0021]
During operation, the function generator 10 of the controller 8 obtains the basic opening command 9 of the combustion air adjustment damper 7 based on the boiler load request command and outputs it to the multiplier 13.
[0022]
Here, when all the burner valves 5 a and 5 b are closed, the gain 14 preset in the fully closed gain setting unit 15 of the gain selector 12 is switched via the switching relay 19 and the switching relay 23. 27 is output to the multiplier 13 as a signal 26, and in the multiplier 13, the gain output from the switching relay 27 of the gain selector 12 in response to the basic opening degree command 9 output from the function generator 10. The signal 26 is multiplied to output a corrected opening command 9 'of the combustion air adjustment damper 7, and the opening of the combustion air adjustment damper 7 is adjusted by the corrected opening command 9' so that an appropriate amount for combustion is used. Air is supplied from the combustion air supply pipe 6 to the burner body 2.
[0023]
In this case, the combustion air is supplied not for fuel combustion but for cooling the burner body 2 and the fuel burners 3a and 3b.
[0024]
When only the fuel A burner valve 5a is opened and the fuel B burner valve 5b is closed, the gain 16 preset in the individual gain setting unit 17 of the gain selector 12 is switched to the switching relay 19. The signal is output from the switching relay 27 to the multiplier 13 via the relay 23, and the multiplier 13 switches the gain selector 12 in response to the basic opening degree command 9 output from the function generator 10. A gain signal 26 output from the relay 27 is multiplied to output a corrected opening command 9 'of the combustion air adjustment damper 7, and the opening of the combustion air adjustment damper 7 is adjusted by the corrected opening command 9'. Then, an appropriate amount of combustion air necessary for the combustion of the fuel A is supplied from the combustion air supply pipe 6 to the burner body 2.
[0025]
When only the fuel B burner valve 5 b is open and the fuel A burner valve 5 a is closed, the gain 20 preset in the individual gain setting unit 21 of the gain selector 12 is passed through the switching relay 23. Is output from the switching relay 27 to the multiplier 13 as a signal 26, and is output from the switching relay 27 of the gain selector 12 in response to the basic opening degree command 9 output from the function generator 10. A gain signal 26 is multiplied to output a corrected opening command 9 'for the combustion air adjustment damper 7. The corrected opening command 9' adjusts the opening of the combustion air adjustment damper 7 so that the fuel B An appropriate amount of combustion air necessary for combustion is supplied from the combustion air supply pipe 6 to the burner body 2.
[0026]
Further, when the burner valve 5a for the fuel A and the burner valve 5b for the fuel B are combined and opened, the gain 24 set in advance in the combination gain setting unit 25 of the gain selector 12 is changed over to the switching relay. 27 is output to the multiplier 13 as a signal 26, and in the multiplier 13, the gain output from the switching relay 27 of the gain selector 12 in response to the basic opening degree command 9 output from the function generator 10. The signal 26 is multiplied to output a corrected opening command 9 ′ of the combustion air adjustment damper 7, and the opening of the combustion air adjustment damper 7 is adjusted by the corrected opening command 9 ′. An appropriate amount of combustion air required for simultaneous combustion is supplied from the combustion air supply pipe 6 to the burner body 2.
[0027]
In this way, it is possible to supply a quantity of combustion air suitable for the combustion of a plurality of types of fuels A and B, and to always stabilize the combustion.
[0028]
Note that the combustion air control device for the combination burner according to the present invention is not limited to the above-described example of illustration, and the type of fuel is not limited to two types, but is fully closed and individual even when there are three or more types. Of course, various changes can be made without departing from the gist of the present invention, such as setting the gain in advance according to the open / closed state of each burner valve as a combination.
[0029]
【The invention's effect】
As described above, according to the combustion air control device for a combination burner of the present invention, it is possible to supply combustion air in an amount suitable for combustion of a plurality of types of fuel, and to constantly stabilize combustion. The effects can be achieved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an example of an embodiment of the present invention.
FIG. 2 is a detailed view of a controller in an example of an embodiment for carrying out the present invention.
FIG. 3 is a schematic configuration diagram of a conventional example.
FIG. 4 is a detailed view of a controller in a conventional example.
FIG. 5 is a diagram representing a function set in the function generator shown in FIGS. 2 and 4;
[Explanation of symbols]
1 Burner Throat 2 Burner Body 3a Fuel Burner 3b Fuel Burner 4a Fuel Supply Pipe 4b Fuel Supply Pipe 5a Burner Valve 5b Burner Valve 6 Combustion Air Supply Pipe 7 Combustion Air Conditioning Damper 8 Controller 9 Basic Opening Command 9 'Correct Open Degree command 10 Function generator 11a Open / close signal 11b Open / close signal 12 Gain selector 13 Multiplier 14 Gain 15 Fully closed gain setter 16 Gain 17 Individual gain setter 20 Gain 21 Individual gain setter 24 Gain 25 Combined gain setter 26 Signal

Claims (1)

Plural types of fuel burners are installed in the burner body provided to open to one burner throat, and a burner valve is provided in the middle of the fuel supply pipe that supplies different fuels to each fuel burner. Combustion air control device for a combination burner provided with a combustion air adjustment damper in the middle of a combustion air supply pipe for supplying air,
A function generator that calculates and outputs the basic opening command of the combustion air adjustment damper based on the load request command, and appropriate depending on the open / close state of each burner valve based on the open / close signal of each burner valve A gain selector that outputs a large gain as a signal, and a corrected opening command of the combustion air adjustment damper by multiplying the basic opening command output from the function generator by the gain signal output from the gain selector A combustion air control device for a combination burner, comprising a controller having a multiplier for outputting the.

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