JP2000111003A - Control method of extraction fluctuation boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method of an extraction fluctuation boiler capable of raising load follow-up performance. SOLUTION: A loss generator output 31 based on an extraction flow rate 29 is added to a generator output demand 20 so as to obtain a loss-consideration generator output demand 33, and a boiler master preceding command 21 is derived from the loss consideration generator output demand 33. The boiler master preceding command 21 is added to a boiler master command 18 for eliminating a main steam pressure deviation 14 of a main steam pressure 9 from a main steam pressure set value 13 so as to obtain a boiler master 23, and the travel of a fuel regulating valve 3 is regulated on the basis of the boiler master 23 and the travel of a governor valve 6 of a high pressure turbine 5 is regulated in such a manner as to eliminate a generator output deviation 25 of the generator output 11 from the generator output demand 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a bleed-air variable boiler.

[0002]

2. Description of the Related Art FIG. 3 shows an example of an industrial boiler for private power generation, wherein 1 is a boiler body, 2 is a furnace of the boiler body 1, and 3 is a fuel supply to the furnace 2 of the boiler body 1. Fuel control valve for adjusting the flow rate, 4 is the boiler body 1
Is a superheater, 5 is a high-pressure turbine, 6 is a governor valve provided on the inlet side of the high-pressure turbine 5, 7 is a low-pressure turbine, 8 is a generator driven by the high-pressure turbine 5 and the low-pressure turbine 7, and the boiler body 1 Is supplied to the furnace 2 to perform combustion, and the main steam superheated by the superheater 4 by the heat of the generated combustion gas is guided to the high-pressure turbine 5. The high-pressure turbine 5 is driven by the generator 8. While power is generated, the steam after driving the high-pressure turbine 5 is guided to a reheater (not shown) of the boiler main body 1, reheated by the reheater, and then introduced into the low-pressure turbine 7. The low-pressure turbine 7 is driven to generate electric power by the generator 8, and the steam after driving the low-pressure turbine 7 is guided to a condenser (not shown), where the steam is boiled. Return to the water supply, water supply not shown Through the economizer of the boiler body 1 is pumped into the furnace 2 is heated by the nodal economizer and furnace 2, is fed to the superheater 4 is adapted to be circulated by.

The control system of a boiler as described above is usually
A pressure detector 10 for detecting the main steam pressure 9; an output detector 12 for detecting the generator output 11;
Subtracter 15 for obtaining the difference between the main steam pressure 9 and the main steam pressure set value 13 detected in the above step, and outputting a main steam pressure deviation 14
And a gain corrector 17 for performing gain correction by a load on the main steam pressure deviation 14 output from the subtractor 15 and outputting a corrected main steam pressure deviation 16, and a correction output from the gain corrector 17. Proportional-integral / differential controller 1 for performing a proportional-integral-differential process on main steam pressure deviation 16 and outputting a boiler master command 18 for eliminating the corrected main steam pressure deviation 16
9, a first function generator 22 for obtaining and outputting a boiler master advance command 21 based on a generator output request 20, and a first function generator 22 for the boiler master command 18 output from the proportional-integral / differential controller 19. A boiler master 23 is obtained by adding the boiler master advance command 21 output from the boiler master, and an adder 24 that outputs an opening degree command of the fuel control valve 3 based on the boiler master 23 to the fuel control valve 3; A difference from the generator output 11 detected by the detector 12 is obtained, and a subtracter 26 that outputs a generator output deviation 25, and a generator output deviation 25 that is output from the subtracter 26 are subjected to proportional integral differentiation processing, It has a configuration including a proportional-integral-differential adjuster 28 that outputs a governor opening degree command 27 for eliminating the generator output deviation 25 to the governor valve 6.

As shown in FIG. 4, a function for increasing or decreasing the boiler master advance command 21 in proportion to an increase or decrease of the generator output request 20 is input to the first function generator 22.

During operation of the boiler, the main steam pressure 9 is detected by the pressure detector 10, the generator output 11 is detected by the output detector 12, and the main steam pressure detected by the pressure detector 10 is detected. The difference between the pressure 9 and the main steam pressure set value 13 is obtained in the subtractor 15, the main steam pressure deviation 14 is output to the gain corrector 17, and the main steam output from the subtractor 15 in the gain corrector 17. The pressure deviation 14 is subjected to gain correction by a load, and the corrected main steam pressure deviation 16 is calculated by a proportional-integral-differential controller 19.
And the corrected main steam pressure deviation 16 output from the gain corrector 17 in the proportional-integral-derivative adjuster 19.
Is subjected to a proportional-integral-differential process, and a boiler master command 18 for eliminating the corrected main steam pressure deviation 16 is output to an adder 24, while a boiler master advance command 21 is generated in a first function generator 22 based on a generator output request 20. It is obtained and output to the adder 24. In the adder 24, the boiler master advance command 21 output from the first function generator 22 is added to the boiler master command 18 output from the proportional-integral-derivative controller 19. Boiler master 23
And the fuel control valve 3 based on the boiler master 23
Is output to the fuel control valve 3 and the fuel control valve 3
Of the fuel supply to the furnace 2 of the boiler body 1 is adjusted.
The difference between 0 and the generator output 11 detected by the output detector 12 is obtained by a subtractor 26, and the generator output deviation 2
5 is output to the proportional-integral-derivative adjuster 28, and the generator-output deviation 25 output from the subtracter 26 is subjected to proportional-integral-differential processing in the proportional-integral-differential adjuster 28 to eliminate the generator output deviation 25. The governor opening command 27 is output to the governor valve 6, the opening of the governor valve 6 is adjusted, and the flow rate of the main steam guided to the high-pressure turbine 5 is adjusted.

[0006]

The control of a boiler as described above is generally performed by APC control (Automatic Pl).
Ant Control), and generator output request 2
Since 0 is the leading element, the load following capability of the boiler is good, and in recent years, it has become the mainstream of boiler control.

However, as shown by the phantom line in FIG. 3, a so-called bleeding variation type in which part of the main steam introduced from the superheater 4 to the high-pressure turbine 5 is bled to a factory or the like as necessary. In the case of a boiler, the main steam discharged from the superheater 4 of the boiler body 1 is supplied to a high-pressure turbine 5.
Since the whole amount is not swallowed, the control will not be successful if only the generator output request 20 is set as the leading element.

For this reason, in a conventional bleed-air fluctuation type boiler, the ABC control (Auto
Although the O.M.O.M.Boiler Control is generally used, it has a disadvantage that the load following capability of the boiler is poor as compared with the case where the generator output request 20 is used as a preceding element.

The present invention has been made in view of the above circumstances, and has as its object to provide a method of controlling a bleed-fluctuation-type boiler capable of improving load following ability.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a method of controlling a bleed-air variable boiler in which a part of main steam introduced from a superheater to a turbine is bleed, and the bleed air is controlled in response to a generator output request. The loss generator output based on the flow rate is added to obtain a loss-considered generator output request, a boiler master advance command is determined based on the loss-considered generator output request, and the main steam pressure deviation between the main steam pressure and the main steam pressure set value. A boiler master is obtained by adding the boiler master advance command to the boiler master command for eliminating the boiler master, the opening degree of the fuel control valve is adjusted based on the boiler master, and the generator output deviation between the generator output request and the generator output is calculated. The present invention relates to a method for controlling a bleed-fluctuation-type boiler, which comprises adjusting the opening of a governor valve of a turbine so as to eliminate it.

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

During the operation of the boiler, the loss generator output based on the bleed air flow is added to the generator output request to obtain a loss-considering generator output request, and a boiler master advance command is determined based on the loss-considering generator output request. The boiler master advance command is added to the boiler master command for eliminating the main steam pressure deviation between the main steam pressure and the set value of the main steam pressure to obtain a boiler master, and the opening of the fuel control valve is determined based on the boiler master. At the same time, the opening of the governor valve of the turbine is adjusted so as to eliminate the generator output deviation between the generator output demand and the generator output.

As a result, when a part of the main steam introduced from the superheater to the high-pressure turbine is bled to a factory or the like as necessary, the loss is added to the generator output demand, It is used as a preceding element, so that the control is properly performed and the load followability of the boiler is improved.

[0014]

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

FIG. 1 shows an example of an embodiment of the present invention. In FIG. 1, the portions denoted by the same reference numerals as those in FIG. 3 represent the same components, and the basic configuration is the same as that of the conventional device shown in FIG. It is the same as that shown in FIG. 1 except that a part of the main steam introduced from the superheater 4 to the high-pressure turbine 5 is bled to a factory or the like as necessary, as shown in FIG. A flow rate detector 30 for detecting the flow rate 29 of the extracted air, and a second function generator 32 for obtaining and outputting the loss generator output 31 based on the flow rate 29 of the extracted air detected by the flow rate detector 30 And an adder that adds the loss generator output 31 output from the second function generator 32 to the generator output request 20 to obtain a loss-considered generator output request 33 and outputs it to the first function generator 22. 34 is additionally provided.

As shown in FIG. 2, a function for increasing or decreasing the loss generator output 31 in proportion to an increase or decrease in the bleed air flow rate 29 is input to the second function generator 32.

In the first function generator 22,
Loss-considered generator output request 33 output from adder 34
, The boiler master advance command 21 is obtained, but the function input to the first function generator 22 is exactly the same as that shown in FIG.

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

During operation of the boiler, the main steam pressure 9 is detected by the pressure detector 10 and the output detector 12 is operated.
Thus, the generator output 11 is detected, and the flow rate detector 30 detects the bleed flow rate 29.

A difference between the main steam pressure 9 detected by the pressure detector 10 and the main steam pressure set value 13 is obtained by a subtractor 15, and a main steam pressure deviation 14 is output to a gain corrector 17, and the gain is calculated. In the corrector 17, the subtractor 15
The gain correction by the load is performed on the main steam pressure deviation 14 output from the controller, the corrected main steam pressure deviation 16 is output to the proportional-integral-differential controller 19, and the proportional-integral-differential controller 1
In 9, the corrected main steam pressure deviation 16 output from the gain corrector 17 is subjected to a proportional integral differentiation process, and a boiler master command 18 for eliminating the corrected main steam pressure deviation 16 is output to the adder 24. A loss generator output 31 is obtained in a function generator 32 based on the bleed air flow rate 29 detected by the flow rate detector 30 and is output to an adder 34. The loss generator output 31 output from the function generator 32 is added, a loss-considered generator output request 33 is obtained and output to the first function generator 22, and the adder 34 is output from the first function generator 22. A boiler master advance command 21 is obtained based on a loss-considered generator output request 33 output from the controller and is output to the adder 24, where the proportional product is calculated. A boiler master advance command 21 output from the first function generator 22 is added to a boiler master command 18 output from the differential controller 19 to obtain a boiler master 23, and the opening degree of the fuel control valve 3 based on the boiler master 23 is determined. A command is output to the fuel control valve 3, the opening of the fuel control valve 3 is adjusted, the fuel flow supplied to the furnace 2 of the boiler body 1 is adjusted, and at the same time, a generator output request 20 and the output A difference from the generator output 11 detected by the detector 12 is obtained in a subtractor 26, and a generator output deviation 25 is output to a proportional-integral-differential adjuster 28, where the subtracter 26 , The generator output deviation 25 output from
Governor opening degree command 2 for eliminating the generator output deviation 25
7 is output to the governor valve 6, the opening of the governor valve 6 is adjusted, and the flow rate of the main steam guided to the high-pressure turbine 5 is adjusted.

As a result, when a part of the main steam introduced from the superheater 4 to the high-pressure turbine 5 is bled to a factory or the like as required, the loss is added to the generator output demand 20. In the form, will be used as a leading element,
The control is properly performed, and the load followability of the boiler is improved.

Thus, the load followability can be improved.

It should be noted that the method of controlling the bleed-air fluctuation type boiler of the present invention is not limited to the above-described illustrated example, and it is needless to say that various changes can be made without departing from the gist of the present invention. .

[0024]

As described above, according to the method of controlling a bleed-air fluctuation type boiler of the present invention, an excellent effect that load followability can be improved can be obtained.

[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 diagram showing a function input to a second function generator shown in FIG. 1;

FIG. 3 is a schematic configuration diagram of a conventional example.

FIG. 4 is a diagram showing a function input to a first function generator shown in FIGS. 1 and 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boiler main body 3 Fuel control valve 4 Superheater 5 High-pressure turbine (turbine) 6 Governor valve 8 Generator 9 Main steam pressure 11 Generator output 13 Main steam pressure set value 14 Main steam pressure deviation 18 Boiler master command 20 Generator output request 21 Boiler master advance command 23 Boiler master 25 Generator output deviation 27 Governor opening command 29 Bleed flow 31 Loss generator output 33 Loss generator output request

Claims (1)

[Claims] 1. A method for controlling a bleed-fluctuation type boiler in which a part of main steam introduced from a superheater to a turbine is bleeding, wherein a loss generator output based on a bleed flow is responded to a generator output request. Addition, obtain a loss-considered generator output request, obtain a boiler master advance command based on the loss-considered generator output request,
A boiler master preceding command is added to a boiler master command for eliminating a main steam pressure deviation between a main steam pressure and a main steam pressure set value to obtain a boiler master, and the opening of the fuel control valve is adjusted based on the boiler master, A method for controlling a bleed-air fluctuation type boiler, comprising adjusting an opening of a governor valve of a turbine so as to eliminate a generator output deviation between a generator output request and a generator output.