JP2013155898A - Steam pressure control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam pressure control method that improves controllability of steam pressure in boiler turbine power generator equipment, and can suppressing generation of vibration when the vibration is generated in setting of a large gain.SOLUTION: A steam pressure control method includes an integration control. When a phenomenon, in which steam pressure deviation (ΔP) between a steam pressure actual result value and a steam pressure set value gets out of a pressure range 37 set in advance (31), and gets into the pressure range 37, occurs more than two times (34), generation of vibration of steam pressure is determined if a time (T) from a time 31, where the steam pressure deviation (ΔP) firstly gets out of the pressure range set in advance, to a time 34, where the steam pressure deviation (ΔP) secondly gets into the pressure range, is not longer than a time (T). A moving average value of integration values of the steam pressure deviation (ΔP) is used for the integration control to correct a fuel amount, and thereby to suppress the vibration.

Description

  TECHNICAL FIELD The present invention relates to a steam pressure control method for a boiler, a turbine, and a generator facility that generates heat by supplying steam generated by supplying fuel to a boiler and absorbing the heat generated by a heat exchanger to a turbine. .

  The boiler equipment used in power generation is equipment that uses high-temperature and high-pressure steam. In power generation using the boiler equipment, fuel is supplied to the boiler for combustion, and the heat generated by absorbing the heat with a heat exchanger. Is used for the boiler, turbine, and generator equipment (hereinafter referred to as “BTG equipment”).

  In the BTG facility, it is necessary to improve the controllability of the boiler steam system so that the boiler tube protection, the turbine blade protection, and the generator do not exceed the power generation output upper limit.

  FIG. 8 is a diagram showing an outline of the boiler steam system and its control. The boiler steam system control mechanism includes a BTG facility 1, a power generation amount command 10 and a fuel amount control unit 12 that controls the amount of fuel supplied to the boiler 2 in accordance with the fuel amount correction amount 22 from the steam pressure control unit 18, and a power generation A governor control unit 14 that controls the amount of steam flowing into the governor valve 3 according to the amount command 10 and a boiler steam pressure that corrects the fuel amount by feedback based on the deviation between the set value of the steam pressure of the boiler 2 and the measured value. And a control unit 18.

  In a boiler steam system, a boiler follow-up control system that controls a fuel amount, a water supply amount, etc. by operating a governor valve in response to a change in the power generation amount command 10 to detect a change in steam pressure or flow rate, or a power generation amount command 10 Is installed in parallel to the boiler and turbine, and boiler-turbine cooperative control is installed to control the opening of the governor valve, the amount of fuel, the amount of water supply, and the like.

  For example, if the amount of fuel supplied to the boiler 2 is excessive, the amount of steam generated increases and the steam pressure of the boiler increases. At this time, if the turbine supply pressure increases, the power generation output becomes excessive. Therefore, the governor control unit 14 closes the governor valve 3 to prevent an increase in the amount of steam supplied to the turbine 4. Thereby, the electric power output from the generator 5 can be kept constant. Moreover, if the amount of fuel supplied to the boiler 2 is insufficient, the amount of steam generated decreases and the steam pressure of the boiler decreases. At this time, if the turbine supply pressure decreases, the power generation output is insufficient. At this time, the governor control unit 14 opens the governor valve 3 to prevent a reduction in the amount of steam supplied to the turbine 4. Thereby, the electric power output from the generator 5 can be kept constant.

  Furthermore, when the amount of steam supplied from the boiler 2 to the turbine 4 changes due to the opening and closing of the governor valve 3, the steam pressure in the boiler 2 (boiler steam pressure) changes. That is, when the amount of fuel supplied to the boiler 2 is excessive, only a part of the steam generated in the boiler 2 is supplied to the turbine 4, so that the boiler steam pressure rises.

  Now, when a certain amount of power is generated, the power generation amount command 10 is a fixed value, but there are the following problems.

  For example, when the amount of fuel supplied to the boiler 2 is insufficient, the amount of steam generated in the boiler 2 is supplied to the turbine 4 so that the boiler steam pressure decreases. For example, the steam pressure deviation 21 (ΔP) is a deviation of the actual steam pressure value 19 from the steam pressure set value 9 so that the boiler steam pressure changing in this way becomes a predetermined set value. Proportional control for correcting using a value obtained by multiplying the proportional gain by the integral control, integral control for correcting the fuel amount using a value obtained by multiplying the integral gain by the value obtained by integrating the steam pressure deviation 21 (ΔP), or the steam pressure deviation Differential control is used in which the fuel amount is corrected using a value obtained by multiplying a value obtained by differentiating 21 (ΔP) by a differential gain. Such a control method is disclosed in Patent Documents 1 and 2.

  However, the steam pressure control system of boilers, turbines, and generator equipment that generates electricity by supplying steam generated by absorbing fuel generated by supplying fuel to the boiler with a heat exchanger is not Therefore, there is a time delay of several minutes until the water vapor is generated, and there is a problem that the fluctuation of the fuel amount by the correction itself induces the vibration of the control system.

  Therefore, when integral control is used, the control performance is improved by increasing the so-called integral gain. However, if the steam pressure deviation (ΔP) starts to oscillate for some reason, the integration of the steam pressure deviation (ΔP) It oscillates 90 ° behind the pressure deviation (ΔP). Therefore, if the fuel amount is corrected using a signal whose phase is 90 ° behind the steam pressure deviation (ΔP), the fuel amount also becomes a signal whose phase is 90 ° behind the steam pressure deviation (ΔP), thus preventing the vibration. Instead, it will help.

  Further, when proportional control is used, the control performance improves if a so-called proportional gain is increased. However, if the steam pressure deviation (ΔP) starts to oscillate for some reason, the steam pressure deviation (ΔP) signal is used. When the fuel amount is corrected, the fuel amount also vibrates in the same phase as the vapor pressure deviation (ΔP), which promotes rather than preventing the vibration.

  On the other hand, when the gain used for the control is reduced, there is a problem that the control response is delayed and the controllability is deteriorated.

JP 2006-2000875 A JP 2004-190913 A

  The present invention has been made to solve the above-described problems, and an object of the present invention is to improve the controllability of the steam pressure and to generate vibration when a large gain is set. Another object of the present invention is to provide a steam pressure control method capable of suppressing the generation thereof.

The inventor has earnestly researched and developed steam pressure control for boilers, turbines, and generator equipment that generates heat by supplying steam generated by supplying fuel to the boiler and absorbing the heat generated by the heat exchanger. When the steam pressure deviation (ΔP) deviates from the preset pressure range and the phenomenon of entering the pressure range occurs more than once, the steam pressure deviation (ΔP) is a preset pressure. When the time (T _P ) from the time when the range departs from the first time to the time when the pressure enters the pressure range for the second time is equal to or less than the preset time (T _V ), the vapor pressure deviation (ΔP) is When it can be determined that the vibration has started, and the steam pressure deviation (ΔP) starts to vibrate, the integrated value of the steam pressure deviation (ΔP) instead of the integrated value of the steam pressure deviation (ΔP). Using the moving average of Found that can be suppressed.

  Furthermore, the steam pressure deviation (ΔP) is provided with a plurality of sections according to the magnitude thereof, the proportional gain is set to a different value for each section, and the steam pressure deviation (ΔP) includes zero. It was found that vibration can be suppressed by setting the proportional gain to zero.

From the above, the gist of the present invention is as follows.
(1) The actual value of boiler steam pressure in boilers, turbines, and generator equipment that generates electricity by supplying steam generated by absorbing fuel generated by supplying fuel to the boiler with a heat exchanger. In order to correct the amount of fuel supplied to the boiler to be controlled, the fuel amount correction amount is calculated using the integral value of the steam pressure deviation (ΔP), which is the deviation of the actual steam pressure value from the steam pressure setting value. In the correction method,
When the fuel amount correction amount is calculated and corrected (hereinafter referred to as “integral control”) using a value obtained by multiplying an integral value of the steam pressure deviation (ΔP) by an integral gain Ki,
The steam pressure deviation (ΔP) deviates from a preset pressure range and the phenomenon of entering the pressure range has occurred twice or more, and the steam pressure deviation (ΔP) is preset. The time of entering the pressure range for the second time from the time when the pressure range deviated for the first time (hereinafter referred to as “first time of departure”) (hereinafter referred to as the “second time of entry”). The second entry time (hereinafter referred to as “switching time”) when the time until (hereinafter referred to as “pseudo-vibration period”) ( _TP ) is equal to or less than the preset time (T _V ). In addition,
From the method of calculating the fuel amount correction amount using a value obtained by multiplying the integral value of the vapor pressure deviation (ΔP) by an integral gain Ki, the integral gain is added to the moving average value of the integral value of the vapor pressure deviation (ΔP). A steam pressure control method comprising a step of changing to a method of calculating a fuel amount correction amount using a value multiplied by Ki.
(2) The moving average of the integral value of the steam pressure deviation (ΔP) is
The integral value of the steam pressure deviation (ΔP) from the integral control start time is a value calculated in parallel,
The integrated value of the steam pressure deviation (ΔP) up to the current time starting from the time that is the moving average time (T _M ) retroactive from the current time is further treated as zero if the retroactive time has no value. steam pressure control method according to (1) the average is a value obtained by dividing the time (T _M) by integrating the values the moving average time (T _M).
(3) What is the moving average of the integral value of the steam pressure deviation (ΔP)?
In the integral value of the steam pressure deviation (ΔP) at the switching time,
The integrated value of the steam pressure deviation (ΔP) up to each time starting from the time after the moving average time ( _TM ) at each time after the switching time (the integrated value is reset at the switching time and before the switching time) the value may be equal to plus the value obtained by dividing the handle) further the moving average time zero (T _M) by integrating the values the moving average time (T _M) according to (1) Steam pressure control method.
(4) The moving average of the integral value of the steam pressure deviation (ΔP) is
Storing the integrated value of the steam pressure deviation (ΔP) after the first departure time and until the switching time;
After the switching time, the pseudo vibration period (T _P ) is the moving average time (T _M ),
A value obtained by further integrating the integral value of the steam pressure deviation (ΔP) up to each time starting from the time that has moved back to the moving average time (T _M ) at each time after the switching time by the moving average time (T _M ). The steam pressure control method according to (1), which is a value obtained by dividing the value by the moving average time (T _M ).
(5) (1) to (4) having a method of calculating and correcting the fuel amount correction amount by using a steam pressure deviation (ΔP) which is a deviation from the steam pressure setting value of the actual steam pressure value. ) The steam pressure control method according to any one of the above.
(6) In the method of calculating and correcting the fuel amount correction amount using a steam pressure deviation (ΔP) that is a deviation from the steam pressure setting value of the actual steam pressure value,
A first correction step of correcting the fuel amount correction amount according to a steam pressure deviation (ΔP) classification;
The steam pressure control according to (5), wherein, in the first correction step, the fuel amount correction amount is set to zero in a section including a value where the steam pressure deviation (ΔP) is zero. Method.

  According to the apparatus and method of the present invention, it is possible to improve the controllability of the steam pressure, and to exert a remarkable effect that vibration generated even at a large gain setting can be suppressed.

Steam pressure deviation control system block diagram Block diagram of control unit Block diagram of (a) Moving average A in integration control unit (B) Moving average B block diagram of the integration control unit Block diagram of (c) moving average C in integration control unit (A) Block diagram of proportional control unit (B) Kpg ₁ table Judgment of vibration start Judgment of vibration start FIG. 5 is a graph when the present invention is implemented, and (a) only having integral control using a moving average A FIG. 4 is a graph when the present invention is implemented, and (b) only having integral control using a moving average B FIG. 5 is a graph when the present invention is implemented, and (c) only having integral control using a moving average C FIG. 4 is a graph when the present invention is implemented, and (d) a case where integral control using a moving average A and proportional control are used. FIG. 6 is a graph when the present invention is implemented, and (e) a case where integral control and proportional control using a moving average B are used. FIG. 6 is a graph when the present invention is implemented, and (f) a case where integral control using a moving average C and proportional control are used. FIG. 4 is a graph when the present invention is carried out, and when Kpg ₁ is used in proportional control in (g) and (d). When the present invention is implemented, and when Kpg ₁ is used in proportional control in (h) and (e) FIG. 4 is a graph when the present invention is implemented, and when Kpg ₁ is used in proportional control in (i) and (f). A graph when a comparative example is implemented, and (a) only having normal integral control A graph in the case of carrying out a comparative example, and (b) having normal integral control and normal proportional control Conceptual diagram of boiler, turbine, generator equipment and control equipment

[First Embodiment]
In a boiler / turbine / generator facility in which steam generated by supplying fuel to a boiler as shown in FIG. 8 is absorbed by a heat exchanger and generated by supplying heat to the turbine, the steam pressure of the boiler This is a method of correcting the amount of fuel supplied to the boiler in order to control the actual value to a constant value.

  Specifically, in the method of calculating and correcting the fuel amount using the integral value of the steam pressure deviation 21 (ΔP) that is a deviation of the actual steam pressure value 19 from the steam pressure set value 5, the steam pressure deviation When (ΔP) starts oscillating, the vapor pressure deviation ((P)) is calculated from a method of calculating a fuel amount correction amount using a value obtained by multiplying an integral value of the vapor pressure deviation (ΔP) by an integral gain Ki. A steam pressure control method comprising a step of changing to a method of calculating a fuel amount correction amount using a value obtained by multiplying an integral gain Ki by a moving average value of integral values of ΔP).

As shown in FIG. 5A, the steam pressure deviation (ΔP) has started to oscillate as the steam pressure deviation 21 (ΔP) deviates from the preset pressure range 37 (first deviation). Thereafter, the pressure range 37 is entered (first entry), the pressure range 37 is exceeded (second departure), and the pressure range 37 is entered (second entry). The time (T _P ) from time 31 when the deviation (ΔP) deviates from the preset pressure range for the first time to time 34 when the pressure enters the pressure range 37 for the second time is preset (T _V ). Certify if:

(Control system configuration)
FIG. 1 shows the basic configuration of the control system of the present invention.

The steam pressure actual measurement value (P) 19 of the steam generated by the boiler 2 is drawn from the drawing point 28 and subtracted from the steam pressure set value (P _N ) 9 at the addition point 29 to obtain the steam pressure deviation (ΔP). It has been calculated.
That is, ΔP = P _N −P.
The steam pressure control unit 18 calculates the fuel amount correction amount 22 (ΔF) with the steam pressure deviation (ΔP) 21 as an input. The fuel amount control unit 12 calculates the fuel amount (F) 23 with the fuel amount correction amount 22 (ΔF) as an input. The calculated fuel amount 23 is given to the boiler 2, and in response to this, new steam is generated, and the temperature of the steam is controlled by the temperature control unit 16. The steam whose temperature is controlled is given to the turbine 4 to become rotational energy, and the generator 5 converts the rotational energy into electric energy to generate electric power.

(Steam pressure control unit)
FIG. 2 shows the configuration of the steam pressure control. The steam pressure control unit includes a vibration start determination unit 80, an integration control unit 50, and a proportional control unit 60. The vibration start determining unit 80 constantly monitors whether or not the steam pressure deviation (ΔP) is oscillating, and when it is determined that the vibration has started, the integral control unit 50 and the proportional control unit 60 notify the fact. Make a notification. The integral control unit 50 calculates the integral control correction amount 58 using the steam pressure deviation (ΔP) as the input from the withdrawal point 28. The proportional control component 60 calculates the proportional control correction amount 68 using the steam pressure deviation (ΔP) as the input from the extraction point 28. The integral control correction amount 58 and the proportional control correction amount 68 are added at the addition point 29 to become the fuel amount correction amount 22.

(Vibration start determination unit)
FIG. 5A describes the outline of the determination that the steam pressure deviation (ΔP) has started to oscillate.

  In FIG. 5A, the vertical axis represents the steam pressure deviation (ΔP), the horizontal axis represents the time (t), 35 is a line indicating the upper limit value of the steam pressure deviation (ΔP), and 36 is the steam. A line indicating a lower limit value of the pressure deviation (ΔP), and 37 is a preset pressure range of the steam pressure deviation (ΔP).

  30 is a graph representing the behavior of the steam pressure deviation (ΔP) from time to time, and intersects with the line 35 representing the upper limit value of the steam pressure deviation (ΔP) at 31 and 32, and the steam pressure deviation (ΔP) ) Crosses the line 36 representing the lower limit at 33 and 34.

  In FIG. 5A, the time corresponding to 31 is the time when the steam pressure deviation (ΔP) deviates from the preset pressure range 37 for the first time, and the time corresponding to 32 is the steam pressure deviation (ΔP). ) Is the time at which the pressure pressure 37 has entered the first time, and the time corresponding to 33 is the time at which the steam pressure deviation (ΔP) has deviated from the preset pressure range 37 for the second time, The time corresponding to 34 is the time when the steam pressure deviation (ΔP) entered the pressure range 37 set in advance for the second time.

Therefore, the time from the time corresponding to 31 to the time corresponding to 34 enters the pressure range from the time when the steam pressure deviation (ΔP) deviates from the preset pressure range for the first time to the second time. This is the time (T _P ) until

As a result of diligent research and development, the inventors have found that when the time (T _P ) from the time of departure from the first time to the time of entering the pressure range at the second time is less than or equal to the preset time (T _V ) It is determined that the steam pressure deviation (ΔP) has started to vibrate, and is a time (switching time) corresponding to 34, which is the time when the judgment is made, and measures for vibration suppression are taken immediately after the switching time. It was found that the vibration can be effectively suppressed.

The preset time (T _V ) is a vibration cycle that normally occurs, and is a time of about 10 to 20 minutes.

(Integration control unit)
As a result of earnest research and development, the inventors use a moving average of the integral value instead of the integral value of the steam pressure deviation (ΔP) used as a means for suppressing vibration after the switching time. By doing so, it was found that the vibration can be effectively suppressed.

  By holding the integration operation, vibration promotion can be suppressed, but it is not possible to control the so-called offset of the steam pressure deviation (ΔP) alone. On the other hand, in the present invention, by using a moving average of integral values, vibration promotion is suppressed and an offset portion can be removed.

(Moving average of integral values)
FIG. 5B describes calculation of the moving average of the integral value of the steam pressure deviation (ΔP). In FIG. 5B, the vertical axis represents the integral value of the steam pressure deviation (ΔP), the horizontal axis represents time (t), 41 represents the current time, and 42 represents the moving average time (T _M ). It is. The moving average of the integrated value of the steam pressure deviation (ΔP) at the current time 41 is a value obtained by further integrating the integrated value of the steam pressure deviation (ΔP) retroactive from the current time to the moving average time (T _M ). It is a value divided by the average time (T _M ). When the integral value of the steam pressure deviation is obtained not discretely but discretely, for example, with a ΔT pitch, a value obtained by further integrating the integral value is a value obtained by multiplying the sum of the integral values existing in the target range by ΔT. Can be obtained as

Here, the moving average time (T _M ) 42 is a time (T _M ) from the time when the steam pressure deviation (ΔP) deviates from the preset pressure range to the second time from the time when it deviates from the preset pressure range. _P ), a preset time (T _V ) for determining the start of vibration, or a preset time other than these.

  Here, when the integrator 51 restarts the integration operation from the time when the notification from the vibration start determination unit is received, the integral value before the time when the notification from the vibration start determination unit is received is regarded as 0 and the integration value is moved. Take the average.

  The first embodiment is classified into three types using a moving average A, a moving average B, and a moving average C depending on how to take a moving average of integral values.

<Form using moving average A>
In the form using the moving average A in the first embodiment, the moving average of the integrated value of the steam pressure deviation (ΔP) is the integrated value of the steam pressure deviation (ΔP) from the integration control start time. Is a value calculated in parallel, and the integrated value of the steam pressure deviation (ΔP) up to the current time starting from the time that is the moving average time ( _TM ) earlier than the current time This is a steam pressure control method using a value (hereinafter referred to as “integrated moving average A”) obtained by dividing the sum of the values as zero when there is no value divided by the moving average time (T _M ).

(Integration control switching)
FIG. 3A shows a block diagram of the integral control unit used in this embodiment. The integration control unit mainly includes an integrator 51 with an integrator reset 52, a switch 56, a moving average calculator 55, and an integration gain 57.

  At the start of control, the integrator 51 is reset by the integrator reset 52 and 0 is input as an initial value. The switch 56 is connected to A.

  When the steam pressure deviation (ΔP) 21 is not oscillating, the steam pressure deviation (ΔP) 21 is input to the integrator 51 and integrated, and the integral gain Ki is multiplied to calculate the integral control correction amount 58. The

In parallel with this, the output of the integrator 51 is sent to the moving average calculator 55 from the control start time, and the steam pressure from the current time to the current time starting from the time that is the moving average time (T _M ). deviation further moving average time (T _M) only integrated value of the integrated value of (△ P) outputs a value obtained by dividing by the moving average time (T _M).

  When the vibration start determination unit notifies that the steam pressure deviation (ΔP) 21 has started to vibrate, the switch 56 is connected to B at the time when the notification is received, and thereafter the steam pressure deviation (Δ A value obtained by multiplying the value obtained by integrating the P) 21 by the integrator 51 with the moving average calculator 55 by the integral gain Ki is output as the integral control correction amount 58.

  With this configuration, the integral value of the steam pressure deviation (ΔP) 21 is moved from the calculation of the fuel amount correction amount based on the integral value of the steam pressure deviation (ΔP) 21 at the time when the notification from the vibration start determining unit is received. It is switched to the calculation of the fuel amount correction amount by the average.

(Moving average of integral values)
The output of the integrator 51 is sent to the moving average calculator 55 from the control start time, and the integration of the steam pressure deviation (ΔP) from the current time to the current time starting from the time that is the moving average time (T _M ) from the current time. While further moving average time value (T _M) by the integrated value and outputs a value obtained by dividing the moving average time (T _M), if there is no value in time going back the in the calculation of the moving average zero Treat as.

<Form using moving average B>
In the form using the moving average B, in the first embodiment, the moving average of the integrated value of the steam pressure deviation (ΔP) is the integrated value of the steam pressure deviation (ΔP) at the switching time. The integrated value of the steam pressure deviation (ΔP) up to each time starting from the time that has moved back to the moving average time ( _TM ) at each subsequent time (the integrated value is reset at the switching time and the value before the switching time is the value obtained by dividing the treated as zero) further moving average time (T _M) by integrating the values the moving average time (T _M), was added as a (hereinafter, referred to as "moving average B integral value".) in It is a certain steam pressure control method.

(Integration control switching)
FIG. 3B shows a block diagram of the integral control unit used in this embodiment. The integration control unit mainly includes an integrator 51 with an integrator reset 52, a switch 56, a holder 53 with a holder reset 54, a moving average calculator 55, and an integration gain 57.

  At the start of control, the integrator 51 is reset by the integrator reset 52 and the holder 53 is reset by the holder reset 54, and 0 is input as an initial value. The switch 56 is connected to A.

  When the steam pressure deviation (ΔP) 21 is not oscillating, the steam pressure deviation (ΔP) 21 is input to the integrator 51 and integrated, and the integral gain Ki is multiplied to calculate the integral control correction amount 58. The At this time, the holder 53 is ready to store the output from the integrator 51 at any time.

  When the vibration start determination unit notifies that the steam pressure deviation (ΔP) 21 has started to vibrate, the value of the integrator is stored in the holder 53 at the time when the notice is received, and the integrator 51 is reset. The switch 56 is connected to B, and thereafter, the value obtained by taking the moving average by the moving average calculator 55 for the value obtained by integrating the steam pressure deviation (ΔP) 21 by the integrator 51 is stored in the holder. A value obtained by multiplying the value added at the addition point 29 by the integral gain Ki is output to the integral control correction amount 58. Since the integral value before the switching time is not input to the moving average calculator 55, the integral value of the steam pressure deviation before the switching time is handled as zero.

  With this configuration, the integral value of the steam pressure deviation (ΔP) 21 is moved from the calculation of the fuel amount correction amount based on the integral value of the steam pressure deviation (ΔP) 21 at the time when the notification from the vibration start determining unit is received. The calculation of the fuel amount correction amount by the average can be switched without causing a discontinuous point.

<Form using moving average C>
In the form using the moving average C, in the first embodiment, the moving average of the integral value of the steam pressure deviation (ΔP) is the steam pressure after the first departure time and until the switching time. The integrated value of the deviation (ΔP) is stored, and the pseudo vibration period (T _P ) is set as the moving average time (T _M ) after the switching time, and the moving average time (T _M ) goes back at each time after the switching time. The sum of integral values of the steam pressure deviations (ΔP) up to the respective times starting from the starting time is divided by the moving average time (T _M ) (hereinafter referred to as “integrated moving average C”). .) Steam pressure control method.

(Integration control switching)
FIG. 3C shows a block diagram of the integral control unit used in this embodiment. The integration control unit mainly includes an integrator 51 with an integrator reset 52, a switch 56, a storage device 59, a moving average calculator 55, and an integration gain 57.

  At the start of control, the integrator 51 is reset by the integrator reset 52 and 0 is input as an initial value. The switch 56 is connected to A.

  When the steam pressure deviation (ΔP) 21 is not oscillating, the steam pressure deviation (ΔP) 21 is input to the integrator 51 and integrated, and the integral gain Ki is multiplied to calculate the integral control correction amount 58. The

Now, after the first departure time for the steam pressure deviation (ΔP) 21, the integrated value of the steam pressure deviation (ΔP) is stored in the storage device 59, and
In the moving average calculator 55 in the subsequent switching time, as the using the value stored in the storage device 59 pseudo vibration period (T _P) of the moving average time (T _M), the movement at each time after switching time average time (T _M) the time that goes back as a starting point the vapor pressure deviation to each time (△ P) of the integration value further moving average time (T _M) only the integral value the moving average time (T _M) The value divided by is output as a moving average value of the integrated value of the steam pressure deviation (ΔP), and the switch 56 is connected to B to take the moving average of the integrated value of the steam pressure deviation (ΔP). A value obtained by multiplying the value by the integral gain Ki is output as the integral control correction amount 58.

  With this configuration, the integral value of the steam pressure deviation (ΔP) 21 is moved from the calculation of the fuel amount correction amount based on the integral value of the steam pressure deviation (ΔP) 21 at the time when the notification from the vibration start determining unit is received. It is switched to the calculation of the fuel amount correction amount by the average.

(Moving average of integral values)
The integrated value of the steam pressure deviation (ΔP) after the first departure time for the steam pressure deviation (ΔP) 21 is stored in the storage device 59, and the moving average time (T _M ) at each time after the switching time. move the value obtained by dividing the sum of integral values at the moving average time (T _M) of the said vapor pressure deviation to each time the back time as a starting point (△ P) of the integrated value of the steam pressure deviation (△ P) Output as an average value.

[Second Embodiment]
In the second embodiment, in addition to the integral control using the integral value of Δp in the first embodiment, a steam pressure deviation (ΔP) which is a deviation from the steam pressure set value of the actual steam pressure value is used. This is a control method including a method of calculating and correcting the fuel amount (proportional control).

  In the proportional control, the proportional gain may be set as a constant value as is normally performed. More preferably, in the present invention, a steam pressure deviation section is provided, and the fuel amount is corrected by using the steam pressure deviation (ΔP) according to the steam pressure deviation (ΔP) section. In the section including the first correction step that includes the value at which the steam pressure deviation (ΔP) is zero, the steam pressure control method is capable of setting the gain to zero.

(Proportional control unit)
FIG. 4A is a diagram showing an outline of the proportional control unit. As shown in FIG. 4A, a gain Kpg ₁ for correcting the proportional gain Kp is arranged in series, and the steam pressure deviation (ΔP) is multiplied by Kp and Kpg ₁ to calculate the proportional control correction amount. This corrects the fuel amount. If Kpg ₁ = 1 (constant), normal proportional control is performed.

FIG. 4B is a diagram showing an outline of the correction gain 1. As shown in FIG. 4B, Kpg ₁ is constituted by a classification table corresponding to the steam pressure deviation (ΔP), and 0 to a1 in which the steam pressure deviation (ΔP) is close to zero. Alternatively, the gain is zero at -c1 to 0.

  In a boiler / turbine / generator facility as shown in FIG. 8, the basic configuration of the control system shown in FIG. 1 is used to correct the amount of fuel supplied to the boiler so as to control the actual steam pressure value of the boiler to a constant value. The method was carried out.

(Comparative example)
The start of vibration was not judged, and even if vibration occurred, integral control and proportional control were performed with a constant gain as usual. FIG. 7A shows the result when only integral control is used without using proportional control. FIG. 7B shows the result when the integral control and the proportional control are used together. In any case, the amplitude of the vibration of the steam pressure deviation increases with the passage of time, and it is clear that the vibration is diffused. It is thought that the cause of vibration expansion is that the gain of integral control and proportional control is too large.

  In Examples 1 to 9 below, the same values as those in the comparative example are used for the magnitudes of gains of integral control and proportional control before the start of vibration.

Example 1
FIG. 6A shows a graph in the case where the embodiment using the moving average A according to the first embodiment is implemented. In this embodiment, as shown in FIG. 3A, the moving average A of the integral value is used as the moving average of the integrated value of the steam pressure deviation (ΔP).

  When calculating the correction amount by the integral control, when the second rush is made to the predetermined range at the time of switching, that is, after making the first deviation from the predetermined range with respect to the steam pressure deviation (ΔP). Then, it recognizes that the vibration has started, and switches the integral value of the steam pressure deviation (ΔP) to the moving average A of the integral value calculated in parallel.

  By controlling the steam pressure deviation (ΔP) using the correction amount by the integral control in this way, the vibration of the steam pressure deviation (ΔP) is compared with the result of the comparative example shown in FIG. Can be converged in a short time.

  In addition, at the point where the steam pressure deviation (ΔP) becomes zero, the correction amount matches the offset value, and it can be confirmed that the correction amount of the fuel amount does not change greatly and is operating stably. .

(Example 2)
FIG. 6B shows a graph in the case where the embodiment using the moving average B according to the first embodiment is implemented. In this embodiment, as shown in FIG. 3B, the moving average B of the integral value is used as the moving average of the integrated value of the steam pressure deviation (ΔP).

  When calculating the correction amount by the integral control, when the second rush is made to the predetermined range at the time of switching, that is, after the first deviation from the predetermined range with respect to the steam pressure deviation (ΔP). Then, it recognizes that the vibration has started, and switches the integrated value of the steam pressure deviation (ΔP) to the moving average B of the integrated values.

  By controlling the steam pressure deviation (ΔP) using the correction amount by the integral control in this way, the vibration of the steam pressure deviation (ΔP) is compared with the result of the comparative example shown in FIG. Can be converged in a short time.

  In addition, at the point where the steam pressure deviation (ΔP) becomes zero, the correction amount matches the offset value, and it can be confirmed that the correction amount of the fuel amount does not change greatly and is operating stably. .

(Example 3)
FIG. 6C shows a graph in the case where the embodiment using the moving average C according to the first embodiment is implemented. In this embodiment, as shown in FIG. 3C, the moving average C of the integral value is used as the moving average of the integrated value of the steam pressure deviation (ΔP).

  When calculating the correction amount by the integral control, when the second rush is made to the predetermined range at the time of switching, that is, after making the first deviation from the predetermined range with respect to the steam pressure deviation (ΔP). Then, it recognizes that the vibration has started, and switches the integrated value of the steam pressure deviation (ΔP) to the moving average C of the integrated value.

  By controlling the steam pressure deviation (ΔP) using the correction amount by the integral control in this way, the vibration of the steam pressure deviation (ΔP) is compared with the result of the comparative example shown in FIG. Can be converged in a short time.

  In addition, at the point where the steam pressure deviation (ΔP) becomes zero, the correction amount matches the offset value, and it can be confirmed that the correction amount of the fuel amount does not change greatly and is operating stably. .

Example 4
FIG. 6D shows a graph when the moving average A is used in the integral control in the second embodiment, and the correction with the correction gain Kpg ₁ is not performed in the proportional control. The integral control is described in FIG. 3A, and the proportional control is described in FIG. 4A, where Kpg ₁ = 1.

  Good results have been obtained even with proportional control. Further, at the point where the steam pressure deviation (ΔP) becomes zero, it can be confirmed that the correction amount does not coincide with the offset value at the start of control, but gradually and consistently coincides.

(Example 5)
FIG. 6E shows a graph when the moving average B is used in the integral control in the second embodiment, and correction using the correction gain Kpg ₁ is not performed in the proportional control. The integral control is described in FIG. 3B, and the proportional control is described in FIG. 4A, where Kpg ₁ = 1.

  Good results have been obtained even with proportional control. Further, at the point where the steam pressure deviation (ΔP) becomes zero, it can be confirmed that the correction amount does not coincide with the offset value at the start of control, but gradually and consistently coincides.

(Example 6)
FIG. 6F shows a graph when the moving average C is used in the integral control in the second embodiment, and correction by the correction gain Kpg ₁ is not performed in the proportional control. The integral control is described in FIG. 3C, and the proportional control is described in FIG. 4A, where Kpg ₁ = 1.

  Good results have been obtained even with proportional control. Further, at the point where the steam pressure deviation (ΔP) becomes zero, it can be confirmed that the correction amount does not coincide with the offset value at the start of control, but gradually and consistently coincides.

(Example 7)
The embodiment using the moving average A a second embodiment implemented, describes the graph in the case of performing correction by modifying the gain KPG ₁ in FIG. 6 (g). The integral control is the one described in FIG. 3A, and the proportional control is the one described in FIGS. 4A and 4B. In calculating the correction amount by proportional control, the correction amount is set to zero when the steam pressure deviation (ΔP) is small by using the gain table described in FIG.

  In this way, by controlling the steam pressure deviation (ΔP) using the correction amount by the integral control and the proportional control, the vibration of the steam pressure deviation (ΔP) can be converged in a short time. Good results have been obtained even with proportional control. Further, at the point where the steam pressure deviation (ΔP) becomes zero, it can be confirmed that the correction amount does not coincide with the offset value at the start of control, but gradually and consistently coincides.

(Example 8)
The embodiment using the moving average B a second embodiment implemented, describes the graph in the case of performing correction by modifying the gain KPG ₁ in FIG. 6 (h). The integral control is the one described in FIG. 3B, and the proportional control is the one described in FIGS. 4A and 4B. In calculating the correction amount by proportional control, the correction amount is set to zero when the steam pressure deviation (ΔP) is small by using the gain table described in FIG.

  In this way, by controlling the steam pressure deviation (ΔP) using the correction amount by the integral control and the proportional control, the vibration of the steam pressure deviation (ΔP) can be converged in a short time. Good results have been obtained even with proportional control. Further, at the point where the steam pressure deviation (ΔP) becomes zero, it can be confirmed that the correction amount does not coincide with the offset value at the start of control, but gradually and consistently coincides.

Example 9
The embodiment using a moving average C a second embodiment implemented, describes the graph in the case of performing correction by modifying the gain KPG ₁ in FIG. 6 (i). The integral control is the one described in FIG. 3C, and the proportional control is the one described in FIGS. 4A and 4B. In calculating the correction amount by proportional control, the correction amount is set to zero when the steam pressure deviation (ΔP) is small by using the gain table described in FIG.

  In this way, by controlling the steam pressure deviation (ΔP) using the correction amount by the integral control and the proportional control, the vibration of the steam pressure deviation (ΔP) can be converged in a short time. Good results have been obtained even with proportional control. Further, at the point where the steam pressure deviation (ΔP) becomes zero, it can be confirmed that the correction amount does not coincide with the offset value at the start of control, but gradually and consistently coincides.

1: Boiler / turbine / generator equipment 2: Boiler 3: Governor valve 4: Turbine 5: Generator 6: Condenser 9: Steam pressure set value 10: Power generation amount command 12: Fuel amount control unit 14: Governor control unit 16: Steam temperature control unit 18: Steam pressure control unit 19: Actual steam pressure value 21: Steam pressure deviation 22: Fuel amount correction amount 23: Fuel amount 28: Extraction point 29: Addition point 50: Integration control unit 51: Integrator 52: integrator reset 53: holder 54: holder reset 55: moving average calculator 56: switch 57: integral gain 58: integral control correction amount 60: proportional control unit 61: first correction gain 67: proportional gain 68: Proportional control correction amount

Claims (6)

Controls the actual steam pressure of the boiler, turbine, and generator equipment that generates electricity by supplying the steam generated by supplying fuel to the boiler and absorbing the heat generated by the heat exchanger to the turbine. Therefore, when correcting the amount of fuel supplied to the boiler, the fuel amount correction amount is calculated and corrected using an integral value of the steam pressure deviation (ΔP) which is a deviation from the steam pressure setting value of the actual steam pressure value. In the method
When the fuel amount correction amount is calculated and corrected (hereinafter referred to as “integral control”) using a value obtained by multiplying an integral value of the steam pressure deviation (ΔP) by an integral gain Ki,
The steam pressure deviation (ΔP) deviates from a preset pressure range and the phenomenon of entering the pressure range has occurred twice or more, and the steam pressure deviation (ΔP) is preset. The time of entering the pressure range for the second time from the time when the pressure range deviated for the first time (hereinafter referred to as “first time of departure”) (hereinafter referred to as the “second time of entry”). The second entry time (hereinafter referred to as “switching time”) when the time until (hereinafter referred to as “pseudo-vibration period”) ( _TP ) is equal to or less than the preset time (T _V ). In addition,
From the method of calculating the fuel amount correction amount using a value obtained by multiplying the integral value of the vapor pressure deviation (ΔP) by an integral gain Ki, the integral gain is added to the moving average value of the integral value of the vapor pressure deviation (ΔP). A steam pressure control method comprising a step of changing to a method of calculating a fuel amount correction amount using a value multiplied by Ki. The moving average of the integral value of the steam pressure deviation (ΔP) is
The integral value of the steam pressure deviation (ΔP) from the integral control start time is a value calculated in parallel,
The integrated value of the steam pressure deviation (ΔP) up to the current time starting from the time that is the moving average time (T _M ) retroactive from the current time is further treated as zero if the retroactive time has no value. steam pressure control method according to claim 1, characterized in that a value obtained by dividing the mean time (T _M) by integrating the values the moving average time (T _M). The moving average of the integral value of the steam pressure deviation (ΔP) is
In the integral value of the steam pressure deviation (ΔP) at the switching time,
The integrated value of the steam pressure deviation (ΔP) up to each time starting from the time after the moving average time ( _TM ) at each time after the switching time (the integrated value is reset at the switching time and before the switching time) the value of claim 1, characterized in that is obtained by adding a value obtained by dividing the handle) further the moving average time zero (T _M) only integrated value of the moving average time (T _M) Steam pressure control method. The moving average of the integral value of the steam pressure deviation (ΔP) is
Storing the integrated value of the steam pressure deviation (ΔP) after the first departure time and until the switching time;
After the switching time, the pseudo vibration period (T _P ) is the moving average time (T _M ),
A value obtained by further integrating the integral value of the steam pressure deviation (ΔP) up to each time starting from the time that has moved back to the moving average time (T _M ) at each time after the switching time by the moving average time (T _M ). The steam pressure control method according to claim 1, wherein the steam pressure is divided by the moving average time (T _M ).   5. The method according to claim 1, further comprising: calculating and correcting the fuel amount correction amount using a steam pressure deviation (ΔP) that is a deviation of the actual steam pressure value from the steam pressure setting value. The steam pressure control method according to Item. In the method of calculating and correcting the fuel amount correction amount using a steam pressure deviation (ΔP) that is a deviation from the steam pressure setting value of the actual steam pressure value,
A first correction step of correcting the fuel amount correction amount according to a steam pressure deviation (ΔP) classification;
6. The steam pressure control according to claim 5, wherein, in the first correction step, the fuel amount correction amount is set to zero in a section including a value where the steam pressure deviation (ΔP) is zero. Method.

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