JP7596129B2 - Power generation system, and control method and program thereof - Google Patents

Description

This disclosure relates to a power generation system, and a control method and program for the system.

Thermal power plants and other facilities often use power generation systems whose main components are a boiler and a steam turbine. These power generation systems use steam generated in the boiler to generate electricity using the steam turbine.

Japanese Patent Application Publication No. 11-182212 JP 2018-185600 A

For example, in the summer, a phenomenon occurs in which the vacuum pressure of the condenser decreases as the outside air temperature rises. In such a case, the generator output is likely to decrease (for example, Patent Document 1), and it may not be possible to obtain the output equivalent to the rated load. In addition, the output may decrease due to, for example, deterioration of the equipment over time (for example, Patent Document 2). If the generator output shorts out in this way, it may not be possible to obtain sufficient power generation, resulting in a power generation shortage.

This disclosure was made in consideration of these circumstances, and aims to provide a power generation system that can increase generator output, as well as a control method and program for the system.

A first aspect of the present disclosure is a power generation system that includes a boiler, a steam turbine that rotates using steam generated in the boiler, a generator that generates electricity by the rotation of the steam turbine, and a system control device that controls the boiler. The system control device includes a correction value setting unit that calculates a correction value based on the deviation between the generator required output and the generator output when the load state is equal to or greater than a threshold value and the load change width is within a predetermined range, and a boiler control unit that increases the generator required output based on the correction value and generates a boiler input command that is a command for controlling the boiler.

A second aspect of the present disclosure is a control method for a power generation system including a boiler, a steam turbine that rotates using steam generated in the boiler, and a generator that generates power by the rotation of the steam turbine, the control method including the steps of: calculating a correction value based on the deviation between the generator required output and the generator output when the load state is equal to or greater than a threshold value and the load change width is within a predetermined range; and increasing the generator required output based on the correction value, and generating a boiler input command that is a command for controlling the boiler.

A third aspect of the present disclosure is a control program for a power generation system including a boiler, a steam turbine that rotates using steam generated in the boiler, and a generator that generates power by the rotation of the steam turbine, the control program causing a computer to execute the following processes when the load state is equal to or greater than a threshold value and the load change width is within a predetermined range: a process for calculating a correction value based on the deviation between the generator required output and the generator output; and a process for increasing the generator required output based on the correction value and generating a boiler input command that is a command for controlling the boiler.

This disclosure has the effect of increasing generator output.

1 is a block diagram illustrating a schematic overall configuration of a power generation system according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example of a hardware configuration of a system control device according to an embodiment of the present disclosure. FIG. 1 is a diagram illustrating a schematic configuration of a system control device according to an embodiment of the present disclosure. 5 is a flowchart illustrating an example of processing by a system control device according to an embodiment of the present disclosure. 11A and 11B are diagrams for explaining the effect of processing by a system control device according to an embodiment of the present disclosure.

A power generation system and a control method thereof according to an embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a block diagram showing a schematic overall configuration of a power generation system 1 according to this embodiment. In Fig. 1, the power generation system 1 includes a boiler 10, a steam turbine 3 that rotates using steam generated in the boiler 10, a generator 5 that generates electricity by the rotation of the steam turbine 3, and a system control device 15 that controls the steam turbine 3. Note that the boiler 10 is not limited to a CFB, and can also be applied to other types of boilers such as an HRSG.
A furnace 2 for burning fuel is provided in the boiler 10. Steam generated in a water-cooled wall 2' provided in the furnace 2 is supplied to a steam turbine 3 through a steam pipe L1. A primary superheater 4a, an attemperator 16, and a secondary superheater 4b are provided in series in the steam pipe L1. Note that, although FIG. 1 shows a case where one attemperator 16 is provided, a configuration in which an additional attemperator 16 is provided in a stage subsequent to the secondary superheater 4b may also be used.

The steam pipe L1 between the boiler 10 and the steam turbine 3 is provided with a steam control valve 6 for adjusting the amount of steam supplied to the steam turbine 3. When a fully variable pressure operation mode is adopted, the steam control valve 6 may be kept fully open regardless of the generator required output (required power generation output) MWD.

The power generation system 1 includes a feedwater pump 8 that supplies water to the water-cooled wall 2' installed in the furnace 2, a condenser 9 that recovers the steam discharged from the steam turbine 3 and returns it to water (liquid), and a pipe L2 that guides the water generated in the condenser 9 to the feedwater pump 8.

In addition, a pressure sensor 11 for measuring the main steam pressure is provided between the secondary superheater 4b and the steam control valve 6 in the steam pipe L1. The measurement value of the pressure sensor 11 is output to the system control device 15 and used to control the steam turbine 3.

In the power generation system 1 having such a configuration, fuel is combusted in the furnace 2, and the water supply pump 8 is started to circulate water through a water-cooled wall 2' provided in the furnace 2, thereby generating steam.
Steam generated in the water-cooled wall 2' of the furnace 2 is guided to the primary superheater 4a and superheated, then cooled in the attemperator 16 and resuperheated in the secondary superheater 4b. The steam resuperheated in the secondary superheater 4b is guided to the steam turbine 3 and used to drive the steam turbine 3. The generator 5 generates electricity by the rotation of the steam turbine 3, and the generated electricity is sent to, for example, an electric power system (not shown).

After driving the steam turbine 3, the steam is led to the condenser 9, where it is converted back into water (liquid). The water generated in the condenser 9 is returned to the feedwater pump 8 via various devices (not shown) installed in the pipe L2, and is reused in the boiler 10.

The system control device 15 controls the boiler 10, etc.

FIG. 2 is a diagram showing an example of a hardware configuration of the system control device 15 according to the present embodiment.
2, the system control device 15 is a computer system, and includes, for example, a CPU 110, a ROM (Read Only Memory) 120 for storing programs executed by the CPU 110, a RAM (Random Access Memory) 130 that functions as a work area when each program is executed, a hard disk drive (HDD) 140 as a large-capacity storage device, and a communication unit 150 for connecting to a network or the like. Note that a solid state drive (SSD) may be used as the large-capacity storage device. These units are connected via a bus 180.

The system control device 15 may also include an input unit such as a keyboard and mouse, and a display unit such as a liquid crystal display device for displaying data.

The storage medium for storing the programs executed by the CPU 110 is not limited to the ROM 120. For example, it may be other auxiliary storage devices such as a magnetic disk, a magneto-optical disk, or a semiconductor memory.

A series of processing steps for realizing the various functions described below are recorded in the form of a program on the hard disk drive 140, etc., and the CPU 110 reads this program into the RAM 130, etc., and executes information processing and arithmetic processing to realize the various functions described below. The program may be pre-installed in the ROM 120 or other storage medium, provided in a state stored in a computer-readable storage medium, or distributed via wired or wireless communication means. Computer-readable storage media include magnetic disks, magneto-optical disks, CD-ROMs, DVD-ROMs, semiconductor memories, etc.

Figure 3 is a diagram showing the schematic configuration of the system control device 15. As shown in Figure 3, the system control device 15 includes a correction value setting unit 20, a main steam pressure setting unit 30, a boiler control unit 40, and a governor control unit 50.

When the load state is equal to or greater than a threshold value and the load change width is within a predetermined range, the correction value setting unit 20 calculates a correction value AM1 based on the deviation between the generator required output MWD and the generator output. Specifically, the correction value setting unit 20 includes a subtraction unit 21, a condition determination unit 22, a signal switching unit 23, a smoothing processing unit 24, a PI control unit 25, a change rate limiting unit 26, a holding unit 27, and a signal switching unit 28.

The subtraction unit 21 calculates the deviation (difference) between the generator required output MWD and the actual output (generator output) and outputs it to the PI control unit 25. In the following explanation, the deviation is indicated as ΔMW. The deviation (ΔMW) is the value obtained by subtracting the actual output from the generator required output MWD.

The condition determination unit 22 performs a condition determination and outputs whether the condition is satisfied or not satisfied. For example, as shown in FIG. 3, a first condition, a second condition, and a third condition are set in the condition determination unit 22 (logical AND). Note that only the first and second conditions may be set, or other conditions may be added. The condition determination unit 22 outputs "condition satisfied" when all set conditions are satisfied, and outputs "condition not satisfied" if even one condition is not satisfied.

The first condition is that the load state is equal to or greater than a threshold value. The threshold value is set based on the rated load. Specifically, the threshold value is set near the rated load (for example, a value that is lower than the rated load by a predetermined margin). That is, the first condition determines that the load state is close to the rated load. The generator required output MWD can be used for the load state. That is, the first condition can be that the generator required output MWD is equal to or greater than a preset threshold value β. In this way, the first condition determines that the load state is (or is close to) the rated load state.

The second condition is that the load change width (load change amount per specified time) is within a specified range. The specified range is preset as a range that can be considered as a steady state with no load change. That is, ideally, the second condition determines that there is no load change (the load is not changing). The load is not changing may be determined, for example, by the absence of a load increase (change) request signal. The load increase request signal is a signal that is input remotely or manually by an operator when the power plant's required load (generator required output MWD) is increased by instructions from the central load dispatching center until the target load (generator output) is reached. If this load increase request signal is not present, it is also possible to determine that there is no load change (the load change width is within a specified range).

The third condition is that the opening of the steam control valve 6 is equal to or greater than the threshold value α. Specifically, the third condition is that the opening of the steam control valve 6 is fully open. For this reason, the threshold value α is set in advance to a value that allows the steam control valve 6 to be determined to be fully open. Note that the threshold value α may be set by adding a predetermined margin to the fully open state.

In this way, the condition determination unit 22 determines whether all conditions are satisfied by treating the first condition, the second condition, and the third condition as AND conditions.

Furthermore, the condition determination unit 22 may determine, as an additional condition (fourth condition), at least one of the following: the outside air temperature is equal to or higher than a predetermined value; and the deviation between the generator required output MWD and the generator output is equal to or higher than a predetermined value.

For example, when the outside air temperature is high in summer, the generator output is likely to be insufficient due to a drop in the vacuum pressure of the condenser 9, etc. In other words, by determining that the outside air temperature is equal to or higher than a predetermined value, it is possible to determine the possibility of an output shortage due to an increase in the outside air temperature. The threshold value is set in advance based on the relationship between the outside air temperature and the amount of generator output shortage.

In addition, a shortage of output in summer can also be determined by determining that the deviation between the generator required output MWD and the generator output is equal to or greater than a predetermined value. The predetermined value is set, for example, based on an allowable value for the deviation between the generator required output MWD and the generator output. Note that a shortage of generator output can occur regardless of the outside air temperature, for example, due to equipment deterioration. Therefore, a shortage of generator output can be determined regardless of the cause by determining that the deviation between the generator required output MWD and the generator output is equal to or greater than a predetermined value.

In other words, it is more preferable for the condition determination unit 22 to determine that all of the first, second, third, and fourth conditions are satisfied as AND conditions.

The signal switching unit 23 outputs either the selection port B1 or the selection port B2 to the output port C1 according to the input of the input port A1. Specifically, when a signal indicating that the condition is satisfied is input to the input port A1, the input to the selection port B1 is output to the output port C1. On the other hand, when a signal indicating that the condition is not satisfied is input to the input port A1, the input to the selection port B2 is output to the output port C1. In other words, when the condition determination unit 22 determines that the condition is satisfied, ΔMW is output, and when the condition determination unit 22 determines that the condition is not satisfied, the signal generated by the signal generator (zero signal) is output.

The smoothing processing unit 24 performs smoothing processing on the signal from the signal switching unit 23. Specifically, the smoothing processing unit 24 performs a change suppression process that suppresses changes over time in ΔMW, which is the deviation between the generator required output MWD and the actual output. Specifically, the change suppression process is performed using a moving average. In other words, ΔMW is smoothed. Even when a zero signal is input from the signal switching unit 23, smoothing processing is performed, but since a zero signal does not change over time, the input is output as is.

In this way, the correction value setting unit 20 performs a change suppression process that suppresses the time change of ΔMW and calculates the correction value AM1 described later, so that sudden changes in the calculated correction value AM1 over time are suppressed. In other words, the time change of the correction value AM1 is also gradual, and sudden generator output is suppressed.

The PI control unit 25 performs PI control based on the signal (i.e., ΔMW) output from the smoothing processing unit 24, and outputs a control value. A lower limit and an upper limit are set in the PI control unit 25. For example, the lower limit is 0, and the upper limit is a (>0). In this way, the control value is limited within the upper and lower limit range, and the range of the output value can be limited.

The change rate limiting unit 26 processes the control signal output from the PI control unit 25 to suppress time-dependent changes. This suppresses sudden time-dependent changes in the control signal.

The holding unit 27 holds the value when the signal output from the change rate limiting unit 26 reaches the actual MW target value. The actual MW target value is the rated output of the plant. In other words, the actual MW target value is the maximum value of the output correction value AM1.

The signal switching unit 28 outputs either the selection port E1 or the selection port E2 to the output port F1 according to the input of the input port D1. Specifically, when a signal indicating that the condition is satisfied is input to the input port D1, the input to the selection port E1 is output to the output port F1. On the other hand, when a signal indicating that the condition is not satisfied is input to the input port D1, the input to the selection port E2 is output to the output port F1. In other words, when the condition determination unit 22 determines that the condition is satisfied, the signal input from the holding unit 27 is output, and when the condition determination unit 22 determines that the condition is not satisfied, the signal generated by the signal generator (zero signal) is output.

In this way, the correction value AM1 is calculated based on ΔMW. The correction value AM1 is based on ΔMW, and the larger ΔMW is, that is, the smaller the actual output is relative to the generator required output MWD, the larger the value is. The calculated correction value AM1 is output to the main steam pressure setting unit 30. Note that when the condition is not met and a zero signal is output from the signal switching unit 28, the correction value AM1 is zero and does not affect subsequent stages.

The main steam pressure setting unit 30 sets the main steam pressure command CM2 based on the generator required output MWD and the correction value AM1. For this reason, the main steam pressure setting unit 30 includes a function unit 31 and an addition unit 32.

The function unit 31 converts the generator required output MWD into the main steam pressure command (before correction) CM1. That is, the function unit 31 performs the conversion based on the relationship between the generator required output MWD and the main steam pressure command CM1 that is preset based on the specifications of the power generation system 1.

The adder 32 corrects the main steam pressure command CM1 by adding the correction value AM1 set by the correction value setting unit 20 to the main steam pressure command CM1 output from the function unit 31, and outputs the main steam pressure command (corrected) CM2. In this way, the main steam pressure command is corrected in the direction of increasing.

In this way, the main steam pressure command CM2 is generated in the main steam pressure setting unit 30. The generated main steam pressure command CM2 is output to the boiler control unit 40.

The boiler control unit 40 generates a boiler input command BID (Boiler Input Demand), which is a command for controlling the boiler 10. As described below, the boiler control unit 40 uses the main steam pressure command CM2 reflecting the correction value AM1, and therefore performs processing to increase the generator demand output MWD based on the correction value AM1. Specifically, the boiler control unit 40 increases the generator demand output MWD based on the deviation between the main steam pressure command CM2 and the main steam pressure, and generates the boiler input command BID.

For this reason, the boiler control unit 40 includes a subtraction unit 41, a PI control unit 42, an addition unit 43, and a function unit 44.

The subtraction unit 41 calculates the deviation (difference) between the main steam pressure command CM2 and the main steam pressure (actual value) and outputs it to the PI control unit 42. The deviation is the value obtained by subtracting the main steam pressure from the main steam pressure command CM2.

The PI control unit 42 performs PI control based on the signal output from the subtraction unit 41 (i.e., the deviation between the main steam pressure command CM2 and the main steam pressure) and outputs a control value. This control value is based on the correction value AM1 output from the correction value setting unit 20, and becomes the correction value AM2 for the generator required output MWD.

The correction value AM2 for the generator required output MWD is based on the deviation between the main steam pressure command CM2 and the main steam pressure, and the smaller the main steam pressure is relative to the main steam pressure command CM2, the larger the correction value AM2 for the generator required output MWD becomes. In other words, since the main steam pressure command CM2 is calculated based on the correction value AM1 generated by the correction value setting unit 20, the larger ΔMW is, i.e., the smaller the actual output is relative to the generator required output MWD, the larger the correction value AM2 becomes.

The adder 43 corrects the generator required output MWD by adding the generator required output MWD to the control value (correction value AM2 for the generator required output MWD) output from the PI control unit 42. Because the correction value AM2 is added to the generator required output MWD, the generator required output MWD is corrected to increase.

The function unit 44 converts the corrected generator required output MWD output from the adder unit 43 into a boiler input command BID and outputs it. The boiler input command BID is used, for example, to create a fuel flow command in the furnace 2 and a feedwater flow command in the water wall 2'. Figure 3 shows the case where it is used to control the discharge conveyor. If the boiler input command BID increases, the fuel flow command in the furnace 2 and the feedwater flow command to the water wall 2' also increase, resulting in an increase in the main steam pressure. In other words, the generator output increases.

The boiler input command BID is not limited to the fuel flow command in the furnace 2, etc., as long as it is a parameter that can increase the main steam pressure and increase the generator output.

The governor control unit 50 controls the opening of the steam control valve (governor) 6. Specifically, the difference between the generator required output MWD and the generator output is calculated by a subtraction unit 51, and the difference is converted into a control signal by a PI control unit 52. The opening of the steam control valve 6 is controlled by this control signal, and the governor opening adjustment control is performed so that the deviation between the generator required output MWD and the generator output becomes zero.

Next, an example of processing by the above-mentioned system control device 15 will be described with reference to FIG. 4. FIG. 4 is a flowchart showing an example of the procedure of the boiler input command output processing according to this embodiment. The flow shown in FIG. 4 is executed repeatedly, for example, at a predetermined control period. In the flow of FIG. 4, a case where all of the first condition, second condition, third condition, and fourth condition are used will be described, but the same processing will be performed even if the number of conditions is different.

First, it is determined whether the first condition is satisfied (S101). If the first condition is not satisfied (NO in S101), the process proceeds to S106.

If the first condition is met (YES in S101), it is determined whether the second condition is met (S102). If the second condition is not met (NO in S102), the process proceeds to S106.

If the second condition is met (YES in S102), it is determined whether the third condition is met (S103). If the third condition is not met (NO in S103), the process proceeds to S106.

If the third condition is met (YES in S103), it is determined whether the fourth condition is met (S104). If the fourth condition is not met (NO in S104), the process proceeds to S106.

If the fourth condition is met (YES in S104), a correction value AM1 is calculated based on the deviation between the generator required output MWD and the generator output (S105).

On the other hand, if at least one of the first condition, the second condition, the third condition, and the fourth condition is not satisfied, the correction value AM1 becomes zero (S106).

Next, the main steam pressure command CM2 is set based on the generator required output MWD and the correction value AM1 (S107). If the correction value AM1 is zero, the main steam pressure command CM2 is set simply based on the generator required output MWD.

Next, a correction value AM2 for the generator required output MWD is calculated based on the deviation between the main steam pressure command CM2 and the main steam pressure (S108).

Next, the generator required output MWD is corrected using the correction value AM2, and the boiler input command BID is output (S109).

In this way, when the generator output is insufficient, particularly when the load state is close to the rated load and there is no load fluctuation (steam control valve 6 is fully open), the boiler input command BID is corrected to increase by the correction value, so that the output can be increased to make up for the output deficiency.

Next, the effect of the processing by the above-mentioned system control device 15 will be explained with reference to Figure 5. Figure 5 shows patterns A and B, with the vertical axis (left axis) representing the main steam pressure, the vertical axis (right axis) representing the steam control valve opening, and the horizontal axis representing the main steam flow rate. In pattern A, the steam control valve 6 is kept fully open and constant. In pattern B, the steam control valve 6 is made variable.

When the generator required output MWD increases and reaches point M, it becomes difficult to increase the generator output because the steam control valve 6 is fully open. For this reason, in the region above point M, as in this embodiment, a correction value is calculated and a correction is made to increase the boiler input command BID as a variable pressure operation region. In this way, the main steam pressure can be increased, making it possible to increase the generator output. In this variable pressure operation region, the turbine is under generator output control (the opening of the steam control valve 6 is constant), and the boiler 10 is under main steam pressure control (corrected by ΔMW).

In this way, the boiler input command BID can be corrected to increase based on ΔMW, making it possible to increase the generator output.

As described above, according to the power generation system and the control method and program of this embodiment, in the power generation system 1 that generates power using the boiler 10 and the steam turbine 3, a correction value is calculated based on the generator required output and the generator output when the load state is a high load state where the load state is equal to or greater than a threshold value, and when there is no (small) load change where the load change range is within a predetermined range. Then, the boiler input command BID is generated by increasing the generator required output MWD using the correction value. Therefore, when the load state is equal to or greater than a threshold value and the load change range is within a predetermined range, the boiler input command BID can be increased. This makes it possible to increase the generator output.

In particular, when the load state is above a threshold and the load change range is within a specified range, it is generally considered unnecessary to increase the generator output, but even if a shortage in generator output occurs due to some cause (e.g., environmental changes or equipment deterioration), it is possible to cover the shortage.

In addition, by applying a correction value based on the generator required output and the generator output, the difference between the generator required output and the generator output can be reduced. By generating a boiler input command BID based on the deviation between the main steam pressure command CM2 set by the generator required output MWD and the correction value and the main steam pressure, the boiler input command BID is generated so as to suppress the difference between the main steam pressure command CM2 and the main steam pressure while taking into account the correction value.

When the outside air temperature is equal to or higher than a predetermined value, or when the deviation between the generator required output MWD and the generator output is equal to or higher than a predetermined value, the output can be increased. For example, when the outside air temperature is high in summer, the output is likely to be insufficient due to a drop in the vacuum pressure of the condenser 9, etc. For this reason, the output is increased by the correction value to cover the shortfall.

This disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the invention.

For example, in the above embodiment, when a request for increasing the load is input, the fuel input amount to the furnace 2 and the water supply amount to the water wall 2' are increased, but the response of the water supply is faster than the response of the fuel in the furnace 2. Therefore, when the fuel flow rate command and the feedwater flow rate command are increased simultaneously, the amount of water supplied to the water wall 2' increases first, and then the temperature in the furnace 2 gradually starts to rise. For this reason, depending on the amount of feedwater supplied to the water wall 2', the outlet superheat degree of the water wall 2' may decrease. In order to avoid such a situation, a part of the feedwater amount may be supplied to the attemperator 16 installed on the steam outlet side of the primary superheater 4a, bypassing the water wall 2', and sprayed as a spray. In this case, the amount of spray in the attemperator 16 increases.
In this way, by bypassing a portion of the water supplied to the water-cooled wall 2' to the attemperator 16, it is possible to prevent a decrease in the degree of superheat at the outlet of the water-cooled wall 2' as described above.
In addition, when a desuperheater 16 is further provided on the steam outlet side of the secondary superheater 4b, the spray amount of each desuperheater 16 may be increased.

The power generation system and the control method and program thereof described in each of the above-described embodiments can be understood, for example, as follows.
A power generation system (1) according to the present disclosure includes a boiler (10), a steam turbine (3) that rotates using steam generated in the boiler, a generator that generates power by the rotation of the steam turbine, and a system control device (15) that controls the boiler. The system control device includes a correction value setting unit (20) that calculates a correction value based on the deviation between a generator required output (MWD) and a generator output when a load state is equal to or higher than a threshold value and a load change width is within a predetermined range, and a boiler control unit (40) that increases the generator required output based on the correction value and generates a boiler input command (BID), which is a command for controlling the boiler.

According to the power generation system of the present disclosure, in a power generation system that generates power using a boiler or steam turbine, a correction value is calculated based on the generator required output and the generator output when the load state is a high load state where the load state is equal to or greater than a threshold value, and when there is no (small) load change where the load change width is within a predetermined range. Then, the generator required output is increased by the correction value to generate a boiler input command. Therefore, when the load state is equal to or greater than a threshold value and the load change width is within a predetermined range, the boiler input command can be increased. This makes it possible to increase the generator output.

In particular, when the load state is above a threshold and the load change range is within a specified range, it is generally considered unnecessary to increase the generator output, but even if a shortage in generator output occurs due to some cause (e.g., environmental changes or equipment deterioration), it is possible to cover the shortage.

In addition, by applying a correction value based on the generator required output and the generator output, the difference between the generator required output and the generator output can be reduced.

The power generation system according to the present disclosure includes a main steam pressure setting unit (30) that sets a main steam pressure command based on the generator required output and the correction value, and the boiler control unit may increase the generator required output based on the deviation between the main steam pressure command and the main steam pressure, and generate the boiler input command.

According to the power generation system of the present disclosure, a boiler input command is generated based on the deviation between the main steam pressure command, which is set based on the generator required output and a correction value, and the main steam pressure, so that the boiler input command is generated to suppress the difference between the main steam pressure command and the main steam pressure while taking into account the correction value.

The power generation system according to the present disclosure includes a steam control valve (6) provided in a steam pipe connecting the boiler and the steam turbine, and the correction value setting unit may calculate the correction value when the load state is equal to or greater than a threshold value, the load change width is within a predetermined range, and the opening degree of the steam control valve is equal to or greater than a threshold value.

According to the power generation system of the present disclosure, even if the opening degree of the steam control valve is equal to or greater than a threshold value and it is difficult to adjust the output increase using the steam control valve, it is possible to increase the boiler input command and increase the output.

In the power generation system according to the present disclosure, the correction value setting unit may calculate the correction value when at least one of the following occurs: the outside air temperature is equal to or higher than a predetermined value, and the deviation between the generator required output and the generator output is equal to or higher than a predetermined value.

According to the power generation system of the present disclosure, the output can be increased when the outside air temperature is equal to or higher than a predetermined value, or when the deviation between the generator output and the required output is equal to or higher than a predetermined value. For example, when the outside air temperature is high in summer, the output is likely to be insufficient due to a drop in the vacuum pressure of the condenser (9), etc. For this reason, the output is increased by the correction value to cover the shortage.

In the power generation system according to the present disclosure, the correction value setting unit may perform a change suppression process that suppresses time changes in the deviation between the generator required output and the generator output, and calculate the correction value.

The power generation system disclosed herein suppresses the change over time in the deviation between the generator required output and the generator output, so the change over time in the correction value also becomes gentler, suppressing sudden increases in generator output.

In the power generation system according to the present disclosure, the correction value setting unit may perform the change suppression process using a moving average.

The power generation system disclosed herein can effectively suppress time variations by using a moving average.

The control method disclosed herein is a control method for a power generation system including a boiler, a steam turbine that rotates using steam generated in the boiler, and a generator that generates electricity by the rotation of the steam turbine, and includes the steps of: calculating a correction value based on the deviation between the generator required output and the generator output when the load state is equal to or greater than a threshold value and the load change width is within a predetermined range; and increasing the generator required output based on the correction value, and generating a boiler input command that is a command for controlling the boiler.

The control program disclosed herein is a control program for a power generation system including a boiler, a steam turbine that rotates using steam generated in the boiler, and a generator that generates electricity by the rotation of the steam turbine, and causes a computer to execute the following processes when the load state is equal to or greater than a threshold value and the load change width is within a predetermined range: a process for calculating a correction value based on the deviation between the generator required output and the generator output; and a process for increasing the generator required output based on the correction value and generating a boiler input command that is a command for controlling the boiler.

1: Power generation system 2: Furnace 2': Water-cooled wall 3: Steam turbine 4a: Primary superheater 4b: Secondary superheater 5: Generator 6: Steam control valve 8: Feed water pump 9: Condenser 10: Boiler 11: Pressure sensor 15: System control device 16: Attemperator 20: Correction value setting unit 21: Subtraction unit 22: Condition determination unit 23: Signal switching unit 24: Smoothing processing unit 25: PI control unit 26: Change rate limiting unit 27: Holding unit 28: Signal switching unit 30: Main steam pressure setting unit 31: Function unit 32: Addition unit 40: Boiler control unit 41: Subtraction unit 42: PI control unit 43: Addition unit 44: Function unit 50: Governor control unit 51: Subtraction unit 52: PI control unit 110: CPU
120: ROM
130: RAM
140: Hard disk drive 150: Communication unit 180: Bus A1: Input port AM1: Correction value AM2: Correction value B1: Selection port B2: Selection port BID: Boiler input command C1: Output port CM1: Main steam pressure command CM2: Main steam pressure command D1: Input port E1: Selection port E2: Selection port F1: Output port L1: Steam piping L2: Piping MWD: Generator required output

Claims (8)

Boiler and
a steam turbine that rotates using steam generated in the boiler;
a generator that generates electricity by rotation of the steam turbine;
A system control device for controlling the boiler;
Equipped with
The system control device includes:
a correction value setting unit that calculates a correction value based on a deviation between a generator output and a required output when the load state is equal to or greater than a threshold value and the load change width is within a predetermined range;
a boiler control unit that increases the generator required output based on the correction value and generates a boiler input command that is a command for controlling the boiler;
A power generation system comprising: a main steam pressure setting unit that sets a main steam pressure command based on the generator required output and the correction value,
The power generation system according to claim 1 , wherein the boiler control unit increases the generator required output based on a deviation between the main steam pressure command and the main steam pressure, and generates the boiler input command. a steam control valve provided in a steam pipe connecting the boiler and the steam turbine;
The power generation system according to claim 1 or 2, wherein the correction value setting unit calculates the correction value when the load state is equal to or greater than a threshold value, the load change width is within a predetermined range, and the opening degree of the steam control valve is equal to or greater than a threshold value. The power generation system according to any one of claims 1 to 3, wherein the correction value setting unit calculates the correction value when at least one of the following occurs: the outside air temperature is equal to or higher than a predetermined value, and the deviation between the generator output requirement and the generator output is equal to or higher than a predetermined value. The power generation system according to any one of claims 1 to 4, wherein the correction value setting unit performs a change suppression process that suppresses a time change in the deviation between the generator required output and the generator output, and calculates the correction value. The power generation system according to claim 5, wherein the correction value setting unit performs the change suppression process using a moving average. A control method for a power generation system including a boiler, a steam turbine that rotates using steam generated in the boiler, and a generator that generates power by the rotation of the steam turbine, comprising:
calculating a correction value based on a deviation between a generator output request and the generator output when the load state is equal to or greater than a threshold value and the load change width is within a predetermined range;
a step of increasing the generator required output based on the correction value and generating a boiler input command which is a command for controlling the boiler;
The control method includes: A control program for a power generation system including a boiler, a steam turbine that rotates using steam generated in the boiler, and a generator that generates power by the rotation of the steam turbine,
a process of calculating a correction value based on a deviation between a generator output request and the generator output when the load state is equal to or greater than a threshold value and the load change width is within a predetermined range;
A process of increasing the generator required output based on the correction value and generating a boiler input command which is a command for controlling the boiler;
A control program for causing a computer to execute the above.