JPS61250404A - Method and device for controlling boiler system with steam turbine for power generation - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for controlling a boiler system equipped with a steam turbine for power generation.

[Prior Art] For example, as shown in FIG. 4, steam from a boiler 40 is supplied to a power generation steam turbine 41, and the surplus steam is supplied to process steam usage equipment 42 for use in various purposes. In the boiler system, a boiler 40 and a turbine 41
In order to ensure stable operation, a steam accumulator 44 is connected to a bypass flow path 43 provided in parallel with the turbine 41, and this steam accumulator 44 absorbs load fluctuations in the process steam using equipment 42. I'll do it.

However, in the above-mentioned conventional boiler system, as shown in FIG.
Since the amount of steam passing through the turbine 41 becomes extremely small as shown by FT, there is a drawback that the amount of power generation decreases.

Moreover, flowing a large amount of steam to the bypass passage side in this way results in extremely poor thermal efficiency since the steam is pressurized in the boiler and then used after being depressurized in the steam accumulator.

[Problems to be Solved by the Invention] An object of the present invention is to solve the problem in a boiler system equipped with a steam turbine for power generation, in which load fluctuations in equipment using process steam are absorbed by an Ipass flow path equipped with a steam accumulator. The purpose is to increase the amount of steam passing through the turbine as much as possible and at the same time reduce the amount of steam passing through the heibus flow path, thereby increasing the amount of power generation and improving thermal efficiency.

[Means for Solving the Problems] In order to solve the above problems, the control method of the present invention supplies steam from a boiler to a power generation steam turbine, supplies the exhaust steam to equipment using process steam, In a boiler system in which load fluctuations in the process steam-using equipment are absorbed by a steam accumulator in a bypass flow path installed in parallel with the steam turbine, the internal pressure of the steam accumulator is detected and the steam load average is determined from the level and slope. This steam load average value is compared with the actual steam load in the process steam using equipment, and if the actual steam load is larger than the steam load average value, the steam corresponding to the difference is transferred from the steam accumulator to the process steam usage equipment. At the same time, the supply of steam from the boiler to the steam accumulator is stopped, and when the average steam load value is larger than the actual steam load, the steam corresponding to the difference is supplied from the boiler to the steam accumulator.

It is characterized by stopping the release of steam from the steam accumulator to equipment using process steam.

Further, the control device of the present invention supplies steam from a boiler to a power generation steam turbine, supplies the surplus steam to equipment using process steam, and provides load fluctuations in the equipment using process steam in parallel to the steam turbine. In a boiler system in which steam is absorbed by a steam accumulator in a bypass flow path, a pressure detector detects the internal pressure of the steam accumulator, a calculation unit calculates the average steam load value from the level and slope of the internal pressure, and a process steam A flow rate detector that detects the actual steam load in the equipment used, a comparator that compares the steam load average value obtained by the above calculation unit with the actual steam load detected by the flow rate detector, and the comparison result. The present invention is characterized in that it is provided with a flow valve controller that opens and closes the flow valves on the primary side and secondary side of the steam accumulator based on the steam accumulator.

[Operation] Steam from the boiler is sent to the steam turbine to drive the generator, and then supplied to the equipment that uses process steam. At the same time, the flow rate detector detects the actual steam load, which is input to the comparator. be done.

On the other hand, in the bypass flow path, the internal pressure of the steam accumulator is detected by a pressure detector, and from the level and gradient of this internal pressure, a steam load average value is determined in a computing unit, and this is input to the comparator.

The above comparator calculates the difference between the average steam load from the calculator and the actual steam load from the flow rate detector, and when the actual steam load is greater than the average steam load, The flow valve on the secondary side of the steam accumulator opens and the flow valve on the primary side closes,
Steam corresponding to the flow rate difference is released from the steam accumulator, and conversely, if the average steam load value is larger than the actual steam load, the downstream flow valve opens and the secondary flow valve closes, Steam corresponding to the flow rate difference flows into the steam accumulator.

As a result, the amount of steam passing through the steam turbine increases significantly, and the amount of steam passing through the bypass flow path decreases, thereby increasing the amount of power generation and improving thermal efficiency. Moreover, the operation of the boiler and steam turbine is very stable.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In the boiler system shown in FIG. 1, l is a boiler, 2 is a steam turbine for power generation, and 3 is a process steam using equipment. Steam generated in boiler l is supplied to steam turbine 2 through main steam pipe 4, and After driving the generator 5 through the steam turbine 2, the surplus steam is supplied to the process steam using equipment 3 via the secondary main steam pipe 7, the header 8, and the process steam pipe 9. It has become.

Further, a bypass flow path 10 is provided between the main steam pipe line 4 and the spaller 8 in parallel with the steam turbine 2,
A steam accumulator 11 is provided in the bypass passage 10.
is connected to the steam accumulator 11, and a flow rate detector 1 is connected to the primary pipe line 12 and the secondary pipe line 13 of the steam accumulator 11, respectively.
4.15 and a flow valve 18.17 are provided, these flow detectors 14.15 and flow valves 18,1? are connected to flow valve controllers 18, 19, respectively.

On the other hand, a pressure detector 20 is attached to the steam accumulator 11 to detect its internal pressure, and this pressure detector 20 is equipped with a calculator that calculates the average value of the steam load from the level and gradient of the internal pressure detected by the pressure detector 20. 21 is connected, and this computing unit 21 and the two flow valve controllers, 18,
19 and the flow rate detector 22 provided in the process steam pipe line 8, the steam load average value outputted from the calculator 21 and the actual steam load detected by the flow rate detector 22 are compared, and the actual steam load detected by the flow rate detector 22 is compared. A control signal according to the difference is sent to the flow valve controller 18.19.
Two comparators 23 and 24 are connected to each output.

The steam load average value Fav output from the arithmetic unit 21 is determined by the following settings. That is,
As shown in FIG. 2, when the internal pressure PA of the steam accumulator 11 is higher than the preset high pressure level PH, the output FAV from the calculator 21 changes at a constant rate while the slope of the fluctuation curve is positive. If it decreases continuously or intermittently and the slope of the fluctuation curve turns negative after reaching the maximum point, the output FAV will maintain the level at the time the maximum point was detected, and conversely, the internal pressure PA will fall below the low pressure level pL. In this case, while the slope of the fluctuation curve is negative, the output FAV increases continuously or intermittently at a constant rate of change, and when the slope of the fluctuation curve changes to positive after reaching the minimum point, the output FAV becomes minimum. It is set to hold 17 bells at the time of point detection, and this output Fav is input to the comparator 23.24 as the steam load average value.

In the boiler system having the above configuration, steam from the boiler 1 is sent to the steam turbine 2 through the main steam supply pipe 4, and after driving the generator 5 here, the steam is transferred to the secondary main steam pipe. , header 8 and process steam line 9 to the process steam using equipment 3. At the same time, this steam is detected by the flow rate detector 22 as an actual steam load F, which is input to two comparators 23 and 24, respectively. be done.

On the other hand, in the steam accumulator 11 provided in the bypass passage 10, the internal pressure PA is detected by the pressure detector 20.
The steam load average value FA is determined by the calculating unit 21 from the changes in the internal pressure level and gradient as described above.
v is determined and input to the comparators 23 and 24, respectively. Then, in the comparators 23 and 24, the steam load average value FAV from the calculator 21 and the flow rate detector 2
A comparison is made with the actual steam load F from 2 and the difference therebetween is determined.

That is, the comparator 23 on the negative side calculates FAV-F, and the comparator 24 on the secondary side calculates F-FAV. If these calculation results are positive, a control signal corresponding to the difference is output from the comparator 23.24 to the flow valve controller 18.19, and the corresponding flow valve 18.17 is opened. Conversely, if the operation result is O or negative,
The flow valve associated with that comparator is held closed.

Therefore, as shown in FIG. 3, when the actual steam load F is larger than the steam load average value FAV, the flow rate valve 17 on the secondary side
opens, the primary side flow valve 1B closes, and steam (shaded area) corresponding to the flow rate difference Fa (= F - FAV) is released from the steam accumulator 11, and conversely,
When the average steam load value FAV is larger than the actual steam load F, the downstream flow valve 1B opens and the secondary flow valve 17 closes, so that the steam corresponding to the flow rate difference Fb (FAV-F) is (indicated part) flows into the steam accumulator 11.

As a result, the amount of steam FT passing through the steam turbine 2 is F
All -Fb is significantly increased compared to the conventional one, and the amount of steam passing through the bypass flow path 10 is reduced, thereby increasing the amount of power generation and improving thermal efficiency. Moreover, the operation of the boiler and steam turbine becomes very stable.

[Effects of the Invention] As described above, according to the present invention, the internal pressure of the steam accumulator is detected, the average steam load value is determined from changes in its level and slope, and the average steam load value and the actual steam load in the equipment using process steam are calculated. If the actual steam load is larger than the average steam load, the difference steam is released from the steam accumulator to the process steam using equipment, and the supply of steam from the boiler to the steam accumulator is stopped. If the steam load average value is larger than the actual steam load, the steam corresponding to the difference is supplied from the boiler to the steam accumulator, and the release of steam from the steam accumulator to the equipment using process steam is stopped. , the amount of steam passing through the bypass flow path can be reduced and the amount of steam passing through the turbine can be increased as much as possible, thereby increasing the amount of power generation and improving thermal efficiency.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a line diagram for explaining how to obtain the steam load average value, and Fig. 3 is a line diagram for explaining the present invention in detail. , FIG. 4 is a block diagram of a conventional example, and FIG. 5 is a diagram for explaining its operation. 1-ψ boiler, 2 fist/steam turbine, 3...
Process steam usage equipment, 10a bypass channel, 11th steam accumulator. 18.17・Flow rate valve, 18.111 @・Flow rate valve controller, 20・Pressure detector, 21・Conflict calculator, 22φ・Flow rate detector, 23.2
4...Comparator, PA...Internal pressure, FAV...Steam load average value, F...Actual steam load. Patent applicant Susumu Sakae Co., Ltd. Figure 1 Figure 2 JP-A r

Claims (1)

[Claims] 1. Supplying steam from a boiler to a power generation steam turbine,
In a boiler system in which the exhaust steam is supplied to equipment using process steam, and load fluctuations in the equipment using process steam are absorbed by a steam accumulator in a bypass passage provided in parallel with the steam turbine, the steam accumulator is Detect the internal pressure, calculate the average steam load value from its level and slope, compare this average steam load value with the actual steam load of the equipment using process steam, and if the actual steam load is greater than the average steam load value, ,
The steam of the difference is released from the steam accumulator to the equipment using process steam, and the supply of steam from the boiler to the steam accumulator is stopped. If the average steam load is larger than the actual steam load, the steam of the difference is released. A method for controlling a boiler system equipped with a steam turbine for power generation, characterized by supplying steam from the boiler to a steam accumulator and stopping the release of steam from the steam accumulator to equipment using process steam. 2. Supply steam from the boiler to a power generation steam turbine,
In a boiler system in which the surplus steam is supplied to equipment using process steam, and load fluctuations in the equipment using process steam are absorbed by a steam accumulator in a bypass passage provided in parallel with the steam turbine, the steam accumulator is A pressure detector that detects the internal pressure, a calculator that calculates the average steam load from the level and gradient of the internal pressure, a flow rate detector that detects the actual steam load in the equipment using process steam, and a A comparator that compares the average steam load value with the actual steam load detected by the flow rate detector, and a flow rate valve controller that opens and closes the flow rate valves on the primary and secondary sides of the steam accumulator based on the comparison results. A control device for a boiler system equipped with a power generation steam turbine.