JPH0749202Y2 - Boiler fuel supply control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to improvement of controllability of a fuel supply control device of a boiler such as a fluidized bed boiler in which a vapor evaporation section and a superheating section are separated.

<Prior art> In a normal boiler system, the evaporator and superheater are integrated, so proper fuel supply control is possible by fuel flow rate control using the operation output of the pressure regulator at the boiler outlet as a master signal. Becomes

That is, the boiler outlet steam temperature is uniquely determined by controlling the fuel flow rate so as to keep the boiler outlet evaporation pressure constant. Therefore, there is a constant relational expression between the boiler load and the steam temperature, and stable control is possible.

<Problems to be solved by the invention> However, in the case of a structure in which the evaporation part and the superheat part are separated, such as a fluidized bed boiler, even if only the fuel supply amount of the evaporation part is controlled by the same method as the conventional method. The boiler output steam temperature is not constantly controlled.

An object of the present invention is to provide a fuel supply amount control device which solves the above problems in such a separated type boiler.

<Means for Solving Problems> The structural feature of the present invention is that the evaporating part and the superheating part are separated,
In the boiler system where fuel is supplied to each,
Pressure controller means that sends the operation output to control the boiler output pressure as a boiler master signal, and the evaporation unit supply amount that sends the evaporation unit fuel supply command as an operation output and the evaporation unit supply heat amount measurement signal as the measured value. A controller means, a superheater supply amount controller means for transmitting a superheater fuel supply command as an operation output using the superheater supply heat quantity measurement signal as a measurement value, and a boiler master signal and the superheater supply heat quantity measurement signal to be input. 1 high selector means, a first low selector means for inputting the output of the high selector means and the superheat section supply calorie measurement signal and supplying the output to the evaporation section supply quantity controller means as a set value, and the boiler master Ratio setting means for multiplying the signal by a fixed ratio, and second high selector means for inputting the output of the ratio setting means and the evaporation part supply heat quantity measurement signal. There the high selector means inputs the output and the evaporator unit supplied heat quantity measurement signal output in that allowed and a second row selector means for supplying a set value to the superheating unit supply amount adjusting meter unit.

<Operation> The output of the first high selector means for inputting the boiler master signal and the superheat section supply heat quantity measurement signal and the output of the first low selector for inputting the superheat section supply heat quantity measurement signal are set in the evaporator section supply quantity controller means The output of the second high selector means which is supplied as a value and which receives the output obtained by multiplying the boiler master signal by a certain ratio and the vaporization part supply heat quantity measurement signal and the output of the second low selector which inputs the evaporation part supply heat quantity measurement signal. It is supplied to the superheater supply amount controller means as a set value.

<Embodiment> An embodiment of the present invention will be described with reference to the accompanying drawings. 1 is a pressure sensor that measures the steam pressure at the boiler outlet, and PV ₁ is the measured value. 2 is a pressure controller, measured value PV ₁
And transmits an operation output MV ₁ that controls operation of the deviation of the pressure setpoint SV _1.

Reference numeral 3 denotes a manual operation device, which selects the operation output MV ₁ or the manual operation output and transmits the boiler master signal BM.

Reference numeral 4 is a fuel flow rate sensor for measuring the amount of heat supplied to the evaporator, and PV ₂ is the measured value. 5 is a fuel flow controllers evaporators, transmits the measured value PV ₂ and the set value operation output MV ₂ the deviation has a control calculation of SV ₂ as the evaporation unit fuel command signal.

6 is a fuel flow rate sensor that measures the amount of heat supplied to the superheater, and PV ₃ is the measured value. 7 is a fuel flow rate control meter superheating zone, transmits the measured value PV ₃ and the set value SV operation output MV ₃ a deviation has a control operation of the ₃ as a superheating unit fuel command signal.

8 is the first high selector, which is a boiler master signal BM
Enter the measured value PV _{3 of the} heat supply to the superheater and. Here, as shown in the figure, in general, the high selector is generally configured to bias (-B) one of the two inputs, but in the present embodiment, , Apply this bias (-B) to the measured value PV ₃ side,
Select the larger input. Reference numeral 9 denotes a first low selector, which inputs the output of the first high selector 8 and the measured value PV ₃ . Here, as shown in the figure, in general, the row selector is usually configured to bias (+ B) to one of the two inputs, but in the present embodiment, the measurement is performed. This bypass (+ B) is applied to the value PV ₃ , and the smaller input is set to the flow controller 5.
Supplied as SV ₂ .

10 is a multiplier, 11 is a ratio setting device, and the multiplier 10 multiplies the boiler master signal BM by the ratio setting value K to obtain K · BM.
Is output.

12 is a second high selector, which is the output signal K of the multiplier 10.
・ Enter the measured value PV ₂ of BM and heat supplied to the evaporator. In this embodiment, as to bias (-B) to the measured value PV ₂ side, selects the input of the larger. 13 is the second low selector, the output of the second high selector 12 and the measured value PV
Enter ₂ . In this embodiment, the measured value PV ₂ is biased (+
B) is applied, and the smaller input is supplied as the set value SV ₃ of the flow controller 7.

In such a configuration, in the normal control state, the boiler master signal BM is selected and supplied as the set value SV ₂ of the flow rate controller 5 of the evaporator, so that the deviation of the heat supplied to the evaporator from this set value is selected. The amount of fuel in the evaporation section is controlled so that there is no

If for some reason the ratio of the amount of fuel in the superheated portion to the amount of fuel in the vaporized portion becomes inconsistent, the measured value PV _{3 of the} heat supplied to the superheated portion is set to the set value SV by the first high selector and low selector
_It is supplied as ₂ , and the amount of fuel in the evaporator is controlled according to PV ₃ .

Similarly, the amount of fuel in the superheated portion is usually proportional to the boiler master signal. The signal K ・ BM is the set value SV ₃ of the flow controller 7 in the superheated portion.
Is selected and supplied, the fuel amount of the superheated portion is controlled so that there is no deviation of the heat supply amount of the superheated portion with respect to this set value.

In the case where the ratio of the evaporation unit fuel quantity and the superheat section fuel amount is no longer constant for some reason, the second high selector, measurements PV ₂ is the set value of the evaporation unit amount of heat supplied by the low selector 12 and 13
It is supplied as SV _{3 and the} amount of fuel in the superheated part is controlled according to PV ₂ .

The amount of fuel in the superheated portion may not be 1: 1 with respect to the amount of fuel in the evaporator portion with respect to the boiler master signal (this is due to the characteristics of the boiler). Is provided with rate setting means for multiplying the rate setting value K which can be changed arbitrarily.

<Effects of the Invention> As described above, according to the present invention, a pressure controller is used even in a boiler system such as a fluidized bed boiler in which the evaporation section and the heating section are different and fuel is supplied to each independently. The fuel amount control by the boiler master signal based on the operation output can be performed with the same feeling as the conventional boiler system, and the controllability can be remarkably improved as compared with the control of only the evaporator.

[Brief description of drawings]

The drawing is a block diagram showing an embodiment of the present invention. 1 ... Pressure sensor, 2 ... Pressure controller, 3 ... Manual controller, 4,6 ... Flow sensor, 5,7 ... Flow controller, 8, 12
...... First and second high selectors, 9,13 …… First and second low selectors, 10 …… Multiplier, 11 …… Ratio setting device

Claims (1)

[Scope of utility model registration request] 1. In a boiler system in which an evaporating section and a superheating section are separated and fuel is supplied to each, pressure regulator means for transmitting an operation output for controlling a boiler output pressure to a constant value as a boiler master signal, Evaporator supply quantity controller that sends the evaporation section supply heat quantity measurement signal as the measured value and the evaporation section fuel supply command as the operation output, and the superheat section supply heat quantity measurement signal as the measured value and the superheat section fuel supply command as the operation output And a first high selector means for inputting a boiler master signal and the above superheated portion supply heat quantity measurement signal, and an output of this high selector means and the above superheated portion supply heat quantity measurement signal A first low selector means for supplying as a set value to the evaporation part supply amount controller means, and a ratio setting hand for multiplying the boiler master signal by a constant ratio. Second high selector means for inputting the output of the ratio setting means and the evaporation part supply heat quantity measurement signal, and output of the high selector means and the evaporation part supply heat quantity measurement signal for supplying the output to the superheat part supply A boiler fuel supply amount control device comprising a second low selector means for supplying a set value to the quantity controller means.