KR20010039185A - Apparatus controlling of steam temperature - Google Patents

Abstract

PURPOSE: A device for adjusting vapor temperature is provided to control main vapor temperature and reheated vapor temperature by deviation between the main vapor temperature and the reheated vapor temperature. CONSTITUTION: A device for adjusting vapor temperature includes a first deviation calculator(31) calculating and outputting deviation between measured main vapor temperature value and set main vapor temperature value, a second deviation calculator(34) calculating and outputting deviation between measured reheated-vapor temperature value and set reheated-vapor temperature value, a first operation unit(50) receiving and calculating calculated value of the first calculator and calculated value of the second calculator and outputting working/stopping signal, a second operation unit(60) for outputting opening value of a fuel valve for adjusting fuel amount when receiving working signal and for stopping the working and maintaining the present state when receiving stopping signal, and a third operation unit for outputting opening value of a reheater damper when receiving working signal and for stopping the working and maintaining the present state when receiving stopping signal for opening adjustment of the reheater damper.

Description

Apparatus controlling of steam temperature

The present invention is a device for controlling the main steam temperature and the reheat steam temperature of the boiler system for controlling the SH (Super-Heater) gas flow rate and the RH gas flow rate using one Re-Heater (RH) damper In particular, the present invention relates to a steam temperature control device for cooperatively controlling the main steam temperature and the reheat steam temperature by reflecting a deviation between the main steam temperature and the reheat steam temperature.

The boiler for controlling the SH gas flow rate and the RH gas flow rate using one reheater damper is provided with independent control devices for controlling the main steam temperature of the SH and the reheat steam temperature of the RH.

1 shows a schematic configuration of the main steam temperature control device and the reheat steam temperature control device.

Figure 1a is a block diagram schematically showing the configuration of an apparatus for adjusting the main steam temperature.

The main steam temperature controller of FIG. 1A obtains a deviation between the main steam temperature measurement value and the main steam temperature set value according to the mega watt demand (MWD), and performs an operation for reducing the amount of fuel to lower the main steam temperature when the obtained deviation is positive. do. If the deviation obtained is negative, an operation for increasing fuel amount is performed to increase the main steam temperature.

Thus, in the apparatus of FIG. 1A, the deviation calculator 11 receives the main steam temperature measurement value and the main steam temperature set value, compares and calculates the deviation, and outputs the obtained deviation. The PI (proportional integral) controller 12 receives the output from the deviation calculator 11 and proportionally integrates it and outputs the calculated value. The summer 13 adds the output from the PI controller 12 and the fuel amount set value according to MWD, and outputs the added addition value as the opening value of the fuel valve for fuel amount adjustment. Thus, the fuel valve not shown is controlled by the opening value.

Figure 1b is a block diagram schematically showing the configuration of the apparatus for adjusting the reheat steam temperature.

The reheat steam temperature control apparatus of FIG. 1b obtains a deviation between the reheat steam temperature measurement value and the reheat steam temperature set value according to MWD, and performs an operation for reducing the reheat damper opening degree to lower the reheat steam temperature when the obtained deviation is positive. In the case of a negative number, the operation to increase the reheater damper opening is performed to increase the reheat steam temperature.

Thus, in the apparatus of FIG. 1B, the deviation controller 14 receives the reheat steam temperature measurement value and the reheat steam temperature setting value, compares the result with the deviation, and outputs the obtained deviation. The PI controller 15 receives the output from the deviation calculator 14 and proportionally integrates it and outputs the calculated value. The deviation calculator 16 receives the output from the PI controller 15 and the reheater bypass temperature measurement value, compares and calculates the deviation, and outputs the obtained deviation. The gain regulator 17 receives the output from the deviation calculator 16 to obtain a gain adjustment value for the reheater bypass temperature, and outputs the obtained gain adjustment value. The PI controller 18 receives the output from the gain adjuster 17 and proportionally integrates it, and outputs the calculated value as the opening value of the reheater damper. Thus, the reheater damper not shown is controlled by the opening value.

2 is a view showing a combustion gas flow of the above-described boiler.

2, the combustion gas flowing in the furnace 21 is distributed to the superheater 23 and the reheater 24 by the reheater damper 22. Therefore, when the opening degree of the reheater damper 22 of the superheater 23 side is increased, the opening degree of the reheater damper 22 of the reheater 24 side is the opening degree of the reheater damper 22 side of the superheater 23 side. Decreases by the same amount as the increase. Accordingly, the flow rate of the combustion gas flowing to the superheater 23 is increased to increase the main steam temperature, and the flow rate of the combustion gas flowing to the reheater 24 is reduced to lower the reheat steam temperature. As such, the amount of combustion gas flowing in the reheater 24 is adjusted according to the temperature state of the reheat steam, and for this purpose, the opening degree of the reheater damper 22 is adjusted.

However, as described above, since the boiler adjusts the opening degree of the reheater damper only by considering the reheating steam temperature, when the reheating steam temperature and the main steam temperature are high at the same time, the opening of the reheater damper is lowered to lower the reheating steam temperature. The amount of combustion gas flowing into the heat is reduced. At this time, if the fuel amount control according to the main steam temperature is delayed, the main steam temperature rises more rapidly than the decrease of the reheat steam temperature. In addition, since the main steam temperature regulating device and the reheat steam temperature adjusting device operate independently without interrelationship, there is a high probability that the above-described problem occurs. Therefore, the safety of the entire boiler and turbine is dangerous, and there is a problem that it is difficult to determine the steam temperature at the time of load change operation.

The present invention has been made to solve the above problems, an object of the present invention is to provide a steam temperature control device for controlling the main steam temperature and the reheat steam temperature by reflecting the deviation of the main steam temperature and the reheat steam temperature In providing.

Figure 1a is a block diagram showing a schematic configuration of a device for adjusting the existing main steam temperature,

Figure 1b is a block diagram showing a schematic configuration of a device for adjusting the existing reheat steam temperature,

2 is a view showing a flow of combustion gas;

Figure 3 is a block diagram showing a schematic configuration of an apparatus for adjusting the steam temperature according to the present invention.

<Description of the code | symbol about the principal part of drawing>

31,34,36: Deviation calculator 32,35,38: PI controller

33: summer 37: gain regulator

39,41: lower limit detector 40,42: upper limit detector

50,60: calculator

In order to achieve the above object, the present invention provides a main steam temperature and a reheat steam temperature of a boiler system for controlling a superheater (SH) gas flow rate and a reheater (RH) gas flow rate using one reheater damper. An apparatus for adjusting, comprising: a first deviation calculator for calculating and outputting a deviation by receiving and comparing a main steam temperature measurement value and a main steam temperature setting value according to MWD; A second deviation calculator for calculating and outputting a deviation by receiving and comparing the reheat steam temperature measurement value and the reheat steam temperature set value according to MWD; The operation value / output signal for controlling the opening degree of the fuel valve and the operation / stop signal for adjusting the opening degree of the reheater damper are calculated by receiving the calculated value output from the first deviation calculator and the calculated value output from the second deviation calculator. First computing means for outputting; Receives the calculated value output from the first deviation calculator and the fuel amount setting value according to MWD, and calculates the calculated calculation value and the fuel amount setting value when the operation signal for controlling the opening degree of the fuel valve is applied from the first calculation means. Second operation means for outputting the result as the opening value of the fuel valve for controlling the fuel amount, and temporarily stopping upon application of a stop signal for adjusting the opening degree of the fuel valve from the first calculation means and maintaining the current state; And a calculation value and a reheater bypass temperature measurement value output from the second deviation calculator, and the inputted calculation value and the reheater bypass when the operation signal for adjusting the opening degree of the reheater damper is applied from the first calculation means. A third calculation means for calculating the pass temperature measurement value and outputting the result of the calculation as the opening value of the reheater damper, and temporarily stopping the application of the stop signal for adjusting the opening degree of the reheater damper from the first calculation means and maintaining the status as it is. It includes.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 3 is a block diagram showing a schematic configuration of a steam temperature control device of the boiler according to the present invention.

In the apparatus of FIG. 3, the first deviation calculator 31 receives the main steam temperature measurement value and the main steam temperature set value according to the MWD, compares the result, and calculates the deviation, and outputs the obtained deviation. The first PI (proportional integral) controller 32 receives the output from the first deviation calculator 31 and proportionally integrates it and outputs the calculated value. The summer 33 adds the output from the first PI controller 32 and the fuel amount set value according to MWD, and outputs the added addition value as the opening value of the fuel valve. Thus, the fuel valve not shown is controlled by the opening value.

Meanwhile, the second deviation calculator 34 provided in the apparatus of FIG. 3 receives the reheat steam temperature measurement value and the reheat steam temperature set value according to the MWD, compares the calculated deviation, and outputs the obtained deviation. The second PI controller 35 receives the output from the second deviation calculator 34, proportionally integrates the output, and outputs the calculated value. The third deviation calculator 36 receives and compares the output from the second PI controller 35 with the reheater bypass temperature measurement, calculates the deviation, and outputs the obtained deviation. The gain regulator 37 receives an output from the third deviation calculator 36 to obtain a gain adjustment value for the reheater bypass temperature, and outputs the obtained gain adjustment value. The third PI controller 38 receives the output from the gain adjuster 37 and proportionally integrates it, and outputs the calculated value as an opening value of the reheater damper. Thus, the reheater damper not shown is controlled by the opening value.

In addition, the operation of the first, second, and third PI controllers 32, 35, and 38 is controlled according to the calculation result of the first, second, and second operation units 50,60. This is explained in more detail.

The first lower limit detector 39, connected to the output of the first deviation calculator 31, determines whether the output from the first deviation calculator 31 is negative. Thus, the first lower limit detector 39 outputs a high level signal if the result is negative and a low level signal if the number is negative. Further, the first upper limit detector 40, connected to the output of the first deviation calculator 31, determines whether the output from the first deviation calculator 31 is positive. Thus, as a result of the determination, the first upper limit detector 40 outputs a high level signal if it is positive, and outputs a low level signal if it is not positive.

On the other hand, the second lower limit detector 41, connected to the output terminal of the second deviation calculator 34, determines whether the output from the second deviation calculator 34 is negative. Thus, the second lower limit detector 41 outputs a high level signal if it is negative, and a low level signal if it is negative. The second upper limit detector 42, which is connected to the output of the second deviation calculator 34, also determines whether the output from the second deviation calculator 34 is positive. Thus, as a result of the determination, the second upper limit detector 42 outputs a high level signal if it is positive, and outputs a low level signal if it is not positive.

In addition, the first operator 50 and the second operator 60 each outputs A, C, B, and D of the first and second lower limit detectors 39 and 41 and the first and second upper limit detectors 40 and 42. Logic multiplication and logical sum operation, and outputs a signal for the operation control of the first, second, third PI controller (32, 35, 38) according to the operation result.

That is, the first operator 50 performs an AND operation on the outputs A and D, an AND operation on the outputs C and B, and performs an OR operation on the result of each AND operation. Thus, the first operator 50 outputs the high level signal or the low level signal to the first PI controller 32 as a result of the logical operation. The first PI controller 32 temporarily stops the operation when the high level signal is applied from the first operator 50 and continues to operate when the low level signal is applied.

In addition, the second operator 60 performs an AND operation on the outputs A and C, an AND operation on the outputs B and D, and performs an OR operation on the result of each AND operation. Thus, the second operator 60 outputs a high level signal or a low level signal to the second and third PI controllers 35 and 38 as a result of the logical operation. The second and third PI controllers 35 and 38 temporarily stop the operation when the high level signal is applied from the second operator 60 and continue to operate when the low level signal is applied.

Thus, when the main steam temperature measurement and the reheat steam temperature measurement are higher than the respective set values, the first and second lower limit detectors 39 and 41 output a low level signal, and the first and second upper limit detectors 40 and 42. Outputs a high level signal. The first operator 50 calculates the outputs A, B, C, and D of each detector, and outputs a low level signal to the first PI controller 32 as a result of the calculation. The first PI controller 32, which has received the low level signal, continuously performs an operation for adjusting the fuel valve opening degree.

The second operator 60 calculates the outputs A, B, C, and D of each detector, and outputs a high level signal to the second and third PI controllers 35 and 38 as a result of the calculation. Upon receiving the high level signal, the second and third PI controllers 35 and 38 temporarily suspend the operation for adjusting the reheater damper opening and maintain the current state.

Thus, in this case, the fuel valve opening is adjusted by only the first PI controller 32 performing an operation for reducing the fuel amount until the main steam temperature measurement becomes lower than the set value.

Next, when the main steam temperature measurement and the reheat steam temperature measurement are lower than the respective set values, the first and second lower limit detectors 39 and 41 output a high level signal, and the first and second upper and second limit detectors 40 and 42. ) Outputs a low level signal. The first operator 50 calculates the outputs A, B, C, and D of each detector, and outputs a low level signal to the first PI controller 32 as a result of the calculation. The first PI controller 32, which has received the low level signal, continuously performs an operation for adjusting the fuel valve opening degree.

The second operator 60 calculates the outputs A, B, C, and D of each detector, and outputs a high level signal to the second and third PI controllers 35 and 38 as a result of the calculation. Upon receiving the high level signal, the second and third PI controllers 35 and 38 temporarily suspend the operation for adjusting the reheater damper opening and maintain the current state.

Thus, in this case, the fuel valve opening is adjusted by only the first PI controller 32 performing an operation for increasing the fuel amount until the main steam temperature measurement becomes higher than the set value.

Further, when the reheat steam temperature measurement is higher than the reheat steam temperature set value and the main steam temperature measurement is lower than the main steam temperature set value, the first and second lower limit detectors 39 and 41 respectively output a high level signal and a low level signal, respectively. The first and second upper limit detectors 40 and 42 output low level signals and high level signals, respectively. The first operator 50 calculates the outputs A, B, C, and D of each detector, and outputs a high level signal to the first PI controller 32 as a result of the calculation. Upon receiving the high level signal, the first PI controller 32 temporarily stops the operation for adjusting the fuel valve opening degree and maintains it as it is.

The second operator 60 calculates the outputs A, B, C, and D of each detector, and outputs a low level signal to the second and third PI controllers 35 and 38 as a result of the calculation. Receiving the low level signal, the second and third PI controllers 35 and 38 continue to operate the reheater damper opening.

Thus, in this case, the second and third PI controllers 35 and 38 perform an operation of lowering the reheater damper opening until the reheat steam temperature measurement is lower than the set value, thereby reducing the amount of combustion gas flowing to the reheater and burning the combustion to the superheater. Increase gas volume As a result, the reheat steam temperature drops and the main steam temperature rises.

When the reheat steam temperature measurement value is lower than the reheat steam temperature setting value and the main steam temperature measurement value is higher than the main steam temperature setting value, the first and second lower limit detectors 39 and 41 respectively output a low level signal and a high level signal. The first and second upper limit detectors 40 and 42 output high and low level signals, respectively. The first operator 50 calculates the outputs A, B, C, and D of each detector, and outputs a high level signal to the first PI controller 32 as a result of the calculation. Upon receiving the high level signal, the first PI controller 32 temporarily stops the operation for adjusting the fuel valve opening degree and maintains it as it is.

The second operator 60 calculates the outputs A, B, C, and D of each detector, and outputs a low level signal to the second and third PI controllers 35 and 38 as a result of the calculation. Receiving the low level signal, the second and third PI controllers 35 and 38 continue to perform an operation for adjusting the opening degree of the reheater damper.

In this case, the second and third PI controllers 35 and 38 perform an operation of increasing the reheater damper opening until the reheat steam temperature measurement is higher than the set value, thereby increasing the amount of combustion gas flowing to the reheater and flowing to the superheater. Reduce the amount of combustion gases As a result, the reheat steam temperature rises and the main steam temperature drops.

As such, the main steam temperature and the reheat steam temperature are efficiently controlled by adjusting the fuel valve opening and the reheater damper opening for the fuel amount by reflecting both the deviations of the main steam temperature and the reheat steam temperature.

As described above, since the steam temperature control device according to the present invention adjusts the steam temperature in response to the deviation of the main steam temperature and the reheat steam temperature, excessive main steam temperature according to the opening degree and fuel amount control of the reheater damper. It is possible to prevent the change of temperature in advance and also provide the advantage of quick control of main steam temperature and reheat steam temperature at the same time.

Claims (4)

In the apparatus for controlling the main steam temperature and the reheat steam temperature of the boiler system that controls the SH (Super-Heater) gas flow rate and RH (Re-Heater) gas flow rate using one reheater damper, A first deviation calculator which calculates and outputs a deviation by receiving the main steam temperature measurement value and the main steam temperature setting value according to the MWD, and comparing the main steam temperature setting values; A second deviation calculator for calculating and outputting a deviation by receiving and comparing the reheat steam temperature measurement value and the reheat steam temperature set value according to MWD; The operation value / output signal for controlling the opening degree of the fuel valve and the operation / stop signal for adjusting the opening degree of the reheater damper are calculated by receiving the calculated value output from the first deviation calculator and the calculated value output from the second deviation calculator. First computing means for outputting; Receives the calculated value output from the first deviation calculator and the fuel amount setting value according to MWD, and calculates the calculated calculation value and the fuel amount setting value when the operation signal for controlling the opening degree of the fuel valve is applied from the first calculation means. Second operation means for outputting the result as the opening value of the fuel valve for controlling the fuel amount, and temporarily stopping upon application of a stop signal for adjusting the opening degree of the fuel valve from the first calculation means and maintaining the current state; And Receives the calculated value and the reheater bypass temperature measurement value output from the second deviation calculator, the input value and the reheater bypass received when the operation signal for adjusting the opening degree of the reheater damper from the first calculation means A third calculation means for calculating the temperature measurement value and outputting the result of the calculation as an opening value of the reheater damper, and temporarily stopping the application of a stop signal for adjusting the opening degree of the reheater damper from the first calculation means and maintaining the current state. Apparatus for adjusting the main steam temperature and the reheat steam temperature comprising. The method of claim 1, wherein the first operation means A first lower limit detector which determines whether the output from the first deviation calculator is negative, outputs a high level signal if the result is negative, and outputs a low level signal if the result is negative; A first upper limit detector for determining whether the output from the first deviation calculator is positive, outputting a high level signal if the determination result is positive, and outputting a low level signal if the determination result is positive; A second lower limit detector which determines whether the output from the second deviation calculator is negative, outputs a high level signal if the result is negative, and outputs a low level signal if the result is negative; A second upper limit detector for determining whether the output from the second deviation calculator is positive, outputting a high level signal if the determination result is positive, and outputting a low level signal if the determination result is positive; Logical AND operation of the output signals of the first lower limit detector and the second upper limit detector, logical AND operation of the output signals of the first upper limit detector and the second lower limit detector, and logical AND operation of the result of the logical AND operation If the result of the logic operation is a high level signal, an operation signal for adjusting the opening degree of the fuel valve is output to the second calculating means. A first operator; And Logical AND operation of the output signals of the first lower limit detector and the second lower limit detector, logical AND operation of the output signals of the first upper limit detector and the second upper limit detector, and logical AND operation of the result of the logical AND operation If the result of the logic operation is a high level signal, an operation signal for adjusting the opening degree of the reheater damper is output to the third calculating means, and if it is a low level signal, a stop signal for adjusting the opening degree of the reheater damper is output to the third calculating means. Apparatus for adjusting the main steam temperature and the reheat steam temperature comprising a second operator to output. The method of claim 2, wherein the second operation means, Receives a calculated value output from the first deviation calculator, and outputs a value calculated by proportionally integrating the input calculated value when the operation signal for opening degree control of the fuel valve is applied from the first calculator, A first PI (proportional integral) controller which pauses upon application of a stop signal for adjusting the opening degree of the fuel valve from the calculator and maintains the current state; And Apparatus for adjusting the main steam temperature and the reheat steam temperature including a totalizer outputting the calculated value output from the first PI controller and the fuel amount set value according to MWD, and outputs the addition value as the opening value of the fuel valve for controlling the fuel amount . The method of claim 2, wherein the third operation means, Receives a calculated value output from the second deviation calculator, outputs a value calculated by proportionally integrating the received calculated value when the operation signal for adjusting the opening degree of the reheater damper is output from the second calculator; A second PI controller which pauses upon application of a stop signal for adjusting the opening degree of the reheater damper from the second operator and maintains the current state; A third deviation calculator that calculates and outputs a deviation by receiving the comparison value and the reheater bypass temperature measurement value output from the second PI controller; A gain adjuster for adjusting and outputting a gain of the reheater bypass temperature according to the deviation output from the third deviation calculator; The calculated value output from the gain adjuster is input, and a value calculated by proportionally integrating the received calculated value when the operation signal for adjusting the opening degree of the reheater damper is applied from the second operator as the opening value of the reheater damper. And a third PI controller for outputting and temporarily stopping upon application of a stop signal for adjusting the opening degree of the reheater damper from the second operator and maintaining the current state.