JP2021032527A - Boiler system - Google Patents

Abstract

To optimize number control plural system control among PI or PID controls.SOLUTION: A boiler system 1 includes at least two systems of boiler groups composed of one or more boilers, and further includes a steam header 6 for collecting steam generated by the boiler groups, steam pressure measurement means 7 for measuring a header pressure value as a steam pressure value inside of the steam header 6, control portions corresponding to boiler groups as the control portions disposed for each of the boiler groups, calculating a necessary steam amount MVn as an operation amount in a control period n by a speed-type PI control or speed-type PID control method so that the header pressure value is agreed with a target pressure value, and controlling a combustion state of the boiler groups, and an average combustion rate correction control portion 30. In a case when deviation in average combustion rates is found among the boiler groups of the different systems, a unit correction amount is moved from a system of a largest average combustion rate to a system of a smallest average combustion rate.SELECTED DRAWING: Figure 1

Description

The present invention relates to a boiler system including at least two boiler groups.

Two boiler groups are installed on the same steam line (same steam header) so that the steam pressure value inside the steam header (hereinafter also referred to as "header pressure value") matches the same target pressure value. There is known a boiler system including a control unit for each system in which the number of boiler groups of the above systems is individually controlled by PI control (or PID control method) (see, for example, Non-Patent Document 1).
In such a boiler system, for example, when the boiler group of one system is started first and the boiler group of another system is started after the steam load is stabilized, the boiler of the first system is started. The combustion rate of the group is high, and the combustion rate of the boiler group of the system launched later continues to be low. After that, even if the steam load increases or decreases, such a dissociated state of the combustion rate is not resolved.
A boiler system in which 10 boilers are installed and 5/5 units control two systems will be specifically described as an example. Assuming that the required steam amount (combustion load) corresponds to the combustion amount of 400% when each of the four boilers burns 100%, if only the first system is started first, the five boilers will each have 80. Stable with% combustion. When the second system is started up in that state, the header pressure value already matches the target pressure value, so that the operation of newly increasing the boiler combustion amount does not work. However, if the control unit of the second system is set to burn at least 20% of one unit, finally, in the first system, five boilers each burn 76%, and the second system. Is stable with 20% combustion of one boiler.
Then, even if the steam load increases or decreases thereafter, the state in which the combustion rate of the boiler group of the first system and the combustion rate of the boiler group of the second system deviate from each other is not resolved.

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Therefore, for example, when only one boiler group of one system is burning, or when only one boiler group of another system is burning with the minimum combustion amount under the control of the number of units, a sudden load fluctuation occurs. If it occurs, it may not be able to follow.
Further, if the combustion rate of the boiler differs greatly depending on the system, it becomes difficult to make the life of the boiler uniform.

The present invention is a case where, in a boiler system including at least two boiler groups, the combustion rate of the boiler group of one system is stable at a higher state than the combustion rate of the boiler group of another system. However, by moving a predetermined amount of combustion from a system with a high combustion rate to a system with a low combustion rate, it is possible to level the combustion rate of each system without changing the combustion amount of the entire boiler system. The purpose is to provide a boiler system for combustion.

(1) The present invention includes at least two boiler groups consisting of one or more boilers, and uses a steam header in which steam generated by the boiler groups of each system gathers and a steam pressure value inside the steam header. A steam pressure measuring means for measuring a certain header pressure value and a control unit provided for each boiler group of each system, and a control cycle n so that the header pressure value matches a preset target pressure value. _{The required steam amount MV n,} which is the operation amount related to the combustion control of the boiler group of each system in the above, is calculated by the speed type PI control or the speed type PID control method, and the combustion state of the boiler group of each system is controlled respectively. A boiler system including a control unit corresponding to the boiler group of the above and an average combustion rate correction control unit for correcting an operation amount related to combustion control of the boiler group for each system of the boiler group. The average combustion rate correction control unit refers to the control unit with _{the identification information of the previous operation amount MV n-1} in the control unit in the control cycle n and the number of boilers controlled by the control unit, or the control unit. The maximum amount of steam that can be output from the boiler controlled by the number of boilers is controlled by the control unit, and the control unit controls the previous operation amount MV _n-1 of the control unit. Calculate the average combustion rate of the control unit in the control cycle n by dividing by the total maximum steam amount of the number of controllable boilers, which is the sum of the maximum output possible steam amounts of each of the boilers. For the unit and the control unit, _{the value obtained by subtracting the preset unit correction amount from the previous operation amount MV n-1 in the} control unit is calculated by the total maximum steam amount of the number of controllable boilers in the control unit. A value obtained by adding the unit correction amount from the _{previous operation amount MV n-1} in the control unit to the minus correction average combustion rate calculation unit for calculating the minus correction average combustion rate which is the divided value and the control unit. In the plus-corrected average combustion rate calculation unit that calculates the plus-corrected average combustion rate, which is the value obtained by dividing the total number of controllable boilers in the control unit, and in any designated control cycle n Regarding the first control unit which is the control unit having the largest combustion rate and the second control unit which is the control unit having the smallest average combustion rate, the average combustion rate of the first control unit and the second control unit are described. The average combustion rate deviation, which is the deviation from the average combustion rate of the control unit, the negatively corrected average combustion rate of the first control unit, and the positively corrected average combustion rate of the second control unit. Regarding the corrected average combustion rate deviation, which is the deviation from the rate, the average combustion rate determination unit that determines whether or not the preset deviation condition is satisfied and the average combustion rate determination unit determine that the deviation condition is satisfied. The present invention relates to a boiler system including an operation amount correction unit that moves the unit correction amount from the operation amount in the first control unit to the operation amount in the second control unit.

(2) In the deviation condition, the average combustion rate deviation between the first control unit and the second control unit and the corrected average combustion rate deviation are both positive in the control cycle n. It is a condition to be a value, and the operation amount correction unit subtracts the previous operation amount MV ¹ _n-1 of the control cycle n in the first control unit from the operation amount MV ¹ _n-1. ^{By correcting the previous operation amount MV 2} _n-1 of the control cycle n in the second control unit to the value obtained by adding the unit correction amount to the operation amount MV ² _n-1. In the control cycle n, the unit correction amount may be moved ^{from the operation amount MV 1} _{n of the} first control unit to the operation amount MV ² _{n of the second control unit.}

(3) The divergence condition is from the control cycle n to the control cycle n + L with respect to the determination counter value L (L ≧ 1) preset for the first control unit and the second control unit. In each control cycle n + i (0 ≦ i ≦ L), the average combustion rate deviation between the first control unit and the second control unit and the corrected average combustion rate deviation are both positive. It is a condition that becomes a value, and the operation amount correction unit calculates the previous operation amount MV ¹ _{n + L-1} of the control cycle n + L in the first control unit, and the unit correction amount from the operation amount MV ¹ _{n + L-1.} In addition to correcting to the subtracted value, the previous operation amount MV ² _{n + L-1} of the control cycle n + L in the second control unit is corrected to the value obtained by adding the unit correction amount to the operation amount MV ² _{n + L-1.} Therefore, in the control cycle n + L, the unit correction amount may be moved ^{from the operation amount MV 1} _{n + L of the} first control unit to the operation amount MV ² _{n + L of the second control unit.}

(4) The boiler system may include two boiler groups.

(5) In the boiler system, the control unit and the average combustion rate correction control unit may be included in one control device.

(6) The average combustion rate correction control unit may not perform the correction process related to the operation amount when the steam amount output cannot be performed in the entire system related to the boiler group.

According to the present invention, in a boiler system including at least two boiler groups, if the combustion rate of the boiler group of one system is higher than the combustion rate of the boiler group of another system, it is stable. Even if there is, by moving a predetermined combustion amount from a system with a high combustion rate to a system with a low combustion rate, it is possible to level the combustion rate of each system without changing the combustion amount of the entire boiler system. It is possible to provide a boiler system that enables it.

It is a block diagram which shows the structure of the boiler system which concerns on one Embodiment. It is a figure which shows the outline of the boiler group which concerns on one Embodiment. It is a functional block diagram which shows the structure of the control device which concerns on one Embodiment. It is a figure which shows the processing flow which concerns on the operation amount correction control which is executed for every control cycle in the boiler system which concerns on one Embodiment.

[First Embodiment]
Hereinafter, the boiler system 1 according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an outline of the boiler system 1. In the following embodiments, a boiler system including two boiler groups will be described, but the same applies to a boiler system including three or more boiler groups. Further, although the case where the boiler group of each system includes a plurality of boilers will be described, the same applies to the case where the boiler group of each system includes one boiler.

The boiler system 1 includes a boiler group 2 including a first boiler group 2A as a boiler group of one system and a second boiler group 2B as a boiler group of another system. The first boiler group 2A and the second boiler group 2B include a plurality of continuous control boilers 20A and a plurality of continuous control boilers 20B, respectively.
The boiler system 1 has a steam header 6 that collects the steam generated in the first boiler group 2A and the second boiler group 2B, and a steam that measures the pressure inside the steam header 6 (hereinafter, also referred to as “header pressure”). The pressure sensor 7, the first system control unit 4A as a control unit corresponding to the boiler group of each system that controls the combustion state of the first boiler group 2A, and the combustion state of the second boiler group 2B are controlled, respectively. A second system control unit 4B and an average combustion rate correction control unit 30 as control units corresponding to the boiler group of the system are provided. The steam pressure value inside the steam header 6 measured by the steam pressure sensor 7 is hereinafter also referred to as “header pressure value PV”.
As will be described later, the average combustion rate correction control unit 30 monitors the combustion control states of the first system control unit 4A and the second system control unit 4B, respectively, and also monitors the combustion control state of the first system control unit 4A and the second system control unit 4B, respectively. The amount of operation related to each combustion control in is corrected. By doing so, in the boiler system 1 including the boiler groups of a plurality of systems, the average combustion rate correction control unit 30 assumes that the combustion rate of the boiler group of one system is higher than the combustion rate of the boiler group of another system. Even when it is stable in a high state, the combustion amount of the entire boiler system 1 can be increased by moving a predetermined combustion amount from the boiler group of the system having a high combustion rate to the boiler group of the system having a low combustion rate. Level the combustion rate of the boiler group of each system without changing.
The boiler system 1 may include a number control device 3 as a control device including a first system control unit 4A, a second system control unit 4B, and an average combustion rate correction control unit 30.
Hereinafter, the boiler system 1 will be described. First, before explaining the average combustion rate correction control unit 30, the control unit of the boiler group of each system and the boiler group of each system will be described.

As shown in FIG. 1, the continuous control boilers 20A and 20B include boiler main bodies 21A and 21B on which combustion is performed, and local control units 22A and 22B for controlling the combustion state of the continuous control boilers 20A and 20B, respectively. ..

The boiler group 2 generates steam to be supplied to the steam use equipment 18.
The steam header 6 is connected to a plurality of continuous control boilers 20A and 20B constituting the boiler group 2 via a steam pipe 11. The downstream side of the steam header 6 is connected to the steam use facility 18 via a steam pipe 12.
The steam header 6 adjusts the mutual pressure difference and pressure fluctuation of the plurality of continuously controlled boilers 20A and 20B by collecting and storing the steam generated in the boiler group 2, and steams the steam whose pressure has been adjusted. It is supplied to the equipment used 18.

The vapor pressure sensor 7 is electrically connected to the first system control unit 4A and the second system control unit 4B, respectively, via the signal line 13. The vapor pressure sensor 7 measures the header pressure, and sends a signal (vapor pressure signal) related to the measured header pressure value PV to the first system control unit 4A and the second system control unit 4B, respectively, via the signal line 13. Send.

The first system control unit 4A and the second system control unit 4B are electrically connected to a plurality of continuous control boilers 20A and 20B, respectively, via signal lines 16A and 16B. The first system control unit 4A and the second system control unit 4B control the combustion state of the continuous control boilers 20A and 20B, respectively, based on the header pressure value PV measured by the vapor pressure sensor 7.

In the above boiler system 1, the steam generated in the first boiler group 2A and the second boiler group 2B can be supplied to the steam use facility 18 via the steam header 6.

Specifically, if the required load (steam consumption) increases due to an increase in the demand for the steam-using equipment 18, and the amount of steam supplied to the steam header 6 is insufficient, the header pressure will decrease. On the other hand, if the required load (steam consumption) decreases due to the decrease in the demand of the steam-using equipment 18, and the amount of steam supplied to the steam header 6 becomes excessive, the header pressure will increase. Therefore, the boiler system 1 can monitor the fluctuation of the required load based on the fluctuation of the header pressure value PV measured by the vapor pressure sensor 7. Then, the boiler system 1 calculates the required steam amount MV, which is the required steam amount according to the steam consumption amount (required load) of the steam use equipment 18, based on the header pressure value PV.

Here, a plurality of boilers 20A and 20B constituting the boiler system 1 of the first embodiment will be described. FIG. 2 is a diagram showing an outline of the boiler group 2 according to the first embodiment.
The boilers 20A and 20B of the first embodiment include continuously controlled boilers capable of continuously changing the load factor and burning.
The continuous control boiler is a boiler whose combustion amount can be continuously controlled at least in the range from the minimum combustion state S1 (for example, the combustion state at a combustion amount of 20% of the maximum combustion amount) to the maximum combustion state S2. Is. The continuous control boiler adjusts the combustion amount by controlling the opening degree (combustion ratio) of the valve that supplies fuel to the burner and the valve that supplies combustion air, for example.

Further, the continuous control of the combustion amount means that the operations and signals in the local control units 22A and 22B are handled step by step in a digital manner (for example, the output (combustion amount) of the boilers 20A and 20B is 1%. Even if it is controlled in increments), it includes the case where the output can be controlled virtually continuously.

The change in the combustion state between the combustion stop state S0 and the minimum combustion state S1 in the boilers 20A and 20B in the first embodiment is controlled by turning on / off the combustion of the boilers 20A and 20B (burners), respectively. To. Then, in the range from the minimum combustion state S1 to the maximum combustion state S2, the combustion amount can be continuously controlled.
More specifically, a unit steam amount U, which is a unit of a variable steam amount, is set for each of the plurality of boilers 20A and 20B. As a result, the boilers 20A and 20B can change the steam amount in units of the unit steam amount U in the range from the minimum combustion state S1 to the maximum combustion state S2.

The unit steam amount U can be appropriately set according to the steam amount (maximum steam amount) in the maximum combustion state S2 of the boilers 20A and 20B, but from the viewpoint of improving the followability of the output steam amount in the boiler system 1 to the required steam amount. , It is preferable to set it to 0.1% to 20% of the maximum steam amount of the boiler 20, and it is more preferable to set it to 1% to 10%.
The output steam amount indicates the amount of steam output by the first boiler group 2A and the second boiler group 2B, and this output steam amount is the total value of the steam amounts output from each of the plurality of boilers 20A and 20B. Represented by.

Priorities are set for each of the plurality of boilers 20A and 20B. The priority order is used by the first system control unit 4A and the second system control unit 4B to select the boilers 20A and 20B for giving a combustion instruction and a combustion stop instruction, respectively. The priority can be set, for example, by using an integer value so that the smaller the numerical value, the higher the priority.
As shown in FIG. 2, for example, when the priorities of "1" to "5" are assigned to each of the first to fifth boilers 20A of the first boiler group 2A, the priority of the first boiler is the highest. High, the priority of Unit 5 is the lowest. This priority is usually changed at predetermined time intervals (for example, 24-hour intervals) by the control of the first system control unit 4A described later.
Similarly, when the priorities of "1" and "5" are assigned to the 4th and 5th units of the boiler 20B of the 2nd boiler group 2B, the priority of the 4th unit is the highest and the priority of the 5th unit is the highest. The ranking is the lowest. This priority is usually changed at predetermined time intervals (for example, 24-hour intervals) by the control of the second system control unit 4B described later.

As described above, the continuous control boilers 20A and 20B include boiler main bodies 21A and 21B on which combustion is performed, and local control units 22A and 22B for controlling the combustion state of the boilers 20A and 20B, respectively.
The local control units 22A and 22B change the combustion state of the boilers 20A and 20B according to the steam consumption, respectively. Specifically, the local control units 22A and 22B are input by a control signal transmitted from the first system control unit 4A and the second system control unit 4B or a manual operation by the driver via the signal lines 16A and 16B, respectively. The combustion state of the boilers 20A and 20B is controlled based on the control signal. Further, the local control units 22A and 22B control the signals used by the first system control unit 4A and the second system control unit 4B, respectively, via the signal lines 16A and 16B, respectively, to the first system control unit 4A and the second system control unit 4A and the second system control unit 4B. It is transmitted to the part 4B. Examples of the signal used by the first system control unit 4A and the second system control unit 4B include the actual combustion state of the boilers 20A and 20B, and other data.

In the boiler system 1 configured as described above, the steam generated in the first boiler group 2A and the second boiler group 2B is supplied to the steam use facility 18 via the steam header 6.

Next, the first system control unit 4A and the second system control unit 4B will be described.
The first system control unit 4A and the second system control unit 4B independently calculate the combustion states of the boilers 20A and 20B according to the required load based on the vapor pressure signal from the vapor pressure sensor 7, and each boiler The first control signal and the second control signal are independently transmitted to the 20A and 20B (local control units 22A and 22B), respectively. As shown in FIG. 1, the first system control unit 4A and the second system control unit 4B have the first control unit 41A and the first storage unit 42A, and the second control unit 41B and the second storage unit 42B, respectively. It is electrically connected to the boilers 20A and 20B via the signal lines 16A and 16B, respectively.

The first system control unit 4A and the second system control unit 4B transmit various instructions to the boilers 20A and 20B via the signal lines 16A and 16B, respectively, and receive various data from the boilers 20A and 20B, respectively. Then, the combustion state and the number of operating units of the boilers 20A and 20B are controlled, respectively. When each of the boilers 20A and 20B receives a signal of a combustion state change instruction from the first system control unit 4A and the second system control unit 4B, respectively, it controls the combustion amount of the corresponding boilers 20A and 20B according to the instruction. The first system control unit 4A and the second system control unit 4B receive information on the combustion state of the boilers 20A and 20B, respectively, via the signal lines 16A and 16B, respectively.

The first storage unit 42A is controlled by the first system control unit 4A, and includes the contents of instructions given to the boiler 20A, information such as the combustion state received from each boiler 20A, and the unit steam amount of each boiler 20A. Information on the setting of the U, information on the setting of the priority of the plurality of boilers 20A, information on the setting on the change of the priority (rotation), and the like are stored.
Further, in the first storage unit 42A, a target pressure value P1 related to combustion control of the first boiler group 2A can be set in advance as a setting condition related to the header pressure value PV measured by the vapor pressure sensor 7.

Similar to the first storage unit 42A, the second storage unit 42B controls the contents of the instructions given to the boiler 20B under the control of the second system control unit 4B, the combustion state received from each boiler 20B, and the like. Information, information on setting the unit steam amount U of each boiler 20B, information on setting the priority of a plurality of boilers 20B, information on setting on changing the priority (rotation), and the like are stored.
Further, in the second storage unit 42B, a target pressure value P1 related to combustion control of the second boiler group 2B can be set in advance as a setting condition related to the header pressure value PV measured by the vapor pressure sensor 7.
As described above, the same value P1 is set for the target pressure value related to the combustion control of the first boiler group 2A and the target pressure value related to the combustion control of the second boiler group 2B.

Next, a detailed configuration related to combustion control in the first system control unit 4A and the second system control unit 4B will be described. Since the configurations related to combustion control in the first system control unit 4A and the second system control unit 4B are basically the same, the first system control unit 4A will be described.
The second system control unit 4B will be described by replacing the first system control unit 4A with the second system control unit 4B in the following description. FIG. 3 is a functional block diagram of the number control device 3.

With reference to FIG. 3, the first system control unit 4A calculates a control amount so that the pressure value (header pressure value) of the steam generated from the first boiler group 2A becomes the preset target pressure value P1. Based on this controlled amount, the combustion amount of the boiler 20A constituting the first boiler group 2A is controlled.
Specifically, the first control unit 41A of the first system control unit 4A includes a required steam amount calculation unit 411A and an output control unit 412A.
That is, the first system control unit 4A uses a predetermined PI algorithm or PID algorithm for the deviation between the header pressure value PV and the target pressure value P1 of the first boiler group 2A set in advance in the first storage unit 42A. ^{By performing feedback control based on the above, the steam amount MV 1} _n required for the header pressure value PV to become the target pressure value P1 is calculated, and the first boiler group 2A is set so as to generate the calculated steam amount MV ¹ _n. Controls the constituent boiler 20A.

Here, the feedback control based on the PID algorithm of the first system control unit 4A will be briefly described.
The first system control unit 4A (specifically, the required steam amount calculation unit 411A) has a header pressure value PV (feedback value) measured by the vapor pressure sensor 7 and a preset target pressure value P1 (set value). ^{The current required vapor pressure MV 1} _n is calculated by the velocity type PID algorithm shown below so that the deviation from and becomes zero. Regarding the speed type PI algorithm, the D control output (change) is omitted in the speed type PID algorithm, and the description thereof will be omitted.

The first system control unit 4A (required steam amount calculation unit 411A) calculates the current required steam amount MV ¹ _n to be generated from the plurality of boilers 20A by the following velocity type calculation formula (Equation 1).
MV ¹ _n = MV ¹ _n-1 + ΔMV ¹ _n ... (Equation 1)
In (Equation 1), MV ¹ _n : current required steam amount (current required steam amount), MV ¹ _n-1 : required steam amount at the time of the previous control cycle (previous required steam amount), ΔMV ¹ _n : previous n This is the change in the required amount of steam from -1 to n this time. Here, the subscript n indicates the number of operations of the iterative operation (nth time: n = 1, 2, ..., A positive integer value of N).
^{In the speed type calculation, only the required steam amount change ΔMV 1} _n from the previous n-1 to the current n is calculated for each control cycle, and the previous required steam amount MV ¹ _n-1 is added to this to obtain the required steam this time. It is a method of calculating the quantity MV ¹ _n.
On the other hand, the PID control algorithm that directly calculates the ^{required steam amount MV 1} _{n for each control cycle is called position calculation.}

^{The required vapor amount change ΔMV 1} _n from the previous n-1 to the current n is calculated by the following (Equation 2).
ΔMV ¹ _n = ΔP _n + ΔI _n + ΔD _n ... (Equation 2)
In (Equation 2), ΔP _n : P control output (change), ΔI _n : I control output (change),
ΔD _n : D control output (change), which can be obtained by the following (Equation 3) to (Equation 5), respectively.
_{^{ΔP 1 n = K 1 P ×}} (e n -e n-1) ········· ( Equation 3)
_{^{ΔI 1 n = K 1 P ×}} (Δt / T I) × e n ······· ( Equation 4)
_{^{ΔD 1 n = K 1 P ×}} (T D / Δt) × (e n -2e n-1 + e n-2) ··· ( Equation 5)
In (Equation 3) to (Equation 5), Delta] t: control ^{cycle, K} _{1 P:} proportional gain, _{T I:} integral time, _{T D:} derivative time, _{e n:} deviation of current _{n, e n-1:} previous The amount of deviation at the time of the control cycle of n-1, _en-2 : The amount of deviation at the time of the control cycle of n-2 two times before.
Deviation e _n at the present time is a target pressure value P1, a difference between the header pressure value PV measured by the vapor pressure sensor 7, it is determined by the following equation (6).
e _n = P1-PV ·············· (Equation 6)

The first system control unit 4A (required steam amount calculation unit 411A) sums each output (change) calculated by (Equation 3), (Equation 4), and (Equation 5) according to (Equation 2). ^{Therefore, the required vapor amount change ΔMV 1} _n from the previous n-1 to the current n is calculated.
Then, the first system control unit 4A (required steam amount calculation unit 411A) adds the required steam amount change ΔMV ¹ _n ^{to the previous required steam amount MV 1} _{n-1 as} in (Equation 1), and this time. The required vapor amount MV ¹ _n can be calculated.
By doing so, the first system control unit 4A (required steam amount calculation unit 411A) calculates the amount of steam required for the header pressure value PV to become the target pressure value P1, and generates the calculated steam amount. The boiler 20A constituting the first boiler group 2A is controlled.
The first system control unit 4A (specifically, the output control unit 412A) controls to output the required steam amount MV ¹ _n calculated by the required steam amount calculation unit 411A.
The first system control unit 4A that controls the first boiler group 2A including the continuous control boiler 20A has been described above.

As for the second system control unit 4B, as described above, the first system control unit 4A, the first control unit 41A, the required steam amount calculation unit 411A, and the output control unit 412A are the second system control unit 4B and the second system control unit 412A, respectively. 2 Read as the control unit 41B, the required steam amount calculation unit 411B, and the output control unit 412B. In addition, the required steam amount MV ¹ _n this time, the required steam amount MV ¹ _n-1 last time, and the required steam amount change ΔMV ¹ _n ^{from the previous n-1 to this time n are MV 2} _n and MV ² _n-1 , respectively. , And ΔMV ² _n , and the proportional gain K ¹ _P is read as K ² _P.

Next, the details of the average combustion rate correction control unit 30 will be described. As shown in FIG. 3, the average combustion rate correction control unit 30 includes an operation amount acquisition unit 31, an average combustion rate calculation unit 32, a minus correction average combustion rate calculation unit 33, and a plus correction average combustion rate calculation unit 34. The average combustion rate determination unit 35 and the operation amount correction unit 36 are provided.

<Operation amount acquisition unit 31>
The operation amount acquisition unit 31 acquires the previous operation amount related to the combustion control in the first system control unit 4A and the second system control unit 4B for each control cycle n. ^{Specifically, the manipulated variable acquisition unit 31 receives the required steam amount MV 1} n-1 as the manipulated variable in the first system control unit 4A in the previous control cycle n-1 from the first system control unit 4A. The identification information of the boiler whose number can be controlled by the first system control unit 4A in the previous control cycle n-1 is acquired. It is assumed that the maximum amount of steam that can be output of each continuous control boiler 20A included in the first boiler group 2A of the system of the first system control unit 4A has been acquired in advance.
^{In addition, the manipulated variable acquisition unit 31 receives the required steam amount MV 2} n-1 as the manipulated variable in the second system control unit 4B in the previous control cycle n-1 from the second system control unit 4B, and the previous control. The identification information of the boiler whose number can be controlled by the second system control unit 4B in the cycle n-1 is acquired. It is assumed that the maximum amount of steam that can be output of each continuous control boiler 20B included in the second boiler group 2B of the system of the second system control unit 4B has been acquired in advance.
Here, the number of controllable boilers is combustion controlled by the first system control unit 4A and the second system control unit 4B, excluding, for example, a spare boiler, an operation OFF boiler, a poor communication boiler, a manual operation boiler, and the like. Means a boiler.
The operation amount acquisition unit 31 stores the acquired operation amount related to the combustion control in the first system control unit 4A and the second system control unit 4B in association with the control cycle n.
The operation amount acquisition unit 31 has been described above, but the present invention is not limited to this. The operation amount acquisition unit 31 determines the maximum amount of steam that can be output by the boiler that can be controlled by the first system control unit 4A and the maximum amount of steam that can be output by the boiler that can be controlled by the second system control unit 4B. You may try to get it.

<Average combustion rate calculation unit 32>
The average combustion rate calculation unit 32 is the total value of the maximum steam amount of the boilers whose number can be controlled by the first system control unit 4A in the control cycle n (hereinafter, “total maximum output steam amount value of the first system control unit 4A””. ) Is calculated. The average combustion rate calculation unit 32 can calculate the total maximum output steam amount of the first system control unit 4A based on the identification information of the boiler whose number can be controlled by the first system control unit 4A. It is assumed that the maximum amount of steam that can be output of each continuous control boiler 20A included in the first boiler group 2A of the system of the first system control unit 4A has been acquired in advance. Further, when the operation amount acquisition unit 31 acquires the maximum output steam amount of the boiler whose number can be controlled by the first system control unit 4A, the maximum output steam of the first system control unit 4A is obtained by totaling these. The total amount may be calculated.
The average combustion rate calculation unit 32 ^{divides the previous operation amount MV 1} _n-1 in the first system control unit 4A by the total maximum output steam amount of the first system control unit 4A, so that the first operation amount in the control cycle n The average combustion rate Av_R ¹ _n of the system control unit 4A is calculated. Specifically, it is represented by the formula 7.
Average combustion rate of 1st system control unit 4A Av_R ¹ _n
= Previous operation amount MV ¹ _n-1 / Total maximum output steam amount of 1st system control unit 4A
(Equation 7)
Similarly, the average combustion rate calculation unit 32 is the total value of the maximum steam amount of the boilers that can be controlled by the second system control unit 4B in the control cycle n (hereinafter, "maximum output steam amount of the second system control unit 4B". "Total value") is calculated. The average combustion rate calculation unit 32 ^{divides the previous operation amount MV 2} _n-1 in the second system control unit 4B by the total maximum output steam amount in the second system control unit 4B, so that the first operation in the control cycle n The average combustion rate Av_R ² _n of the system control unit 4A is calculated. Specifically, it is represented by Equation 8.
Average combustion rate of 2nd system control unit 4B Av_R ² _n
= Previous operation amount MV ² _n-1 / Total maximum output steam amount of 2nd system control unit 4B
(Equation 8)
The average combustion rate in the control cycle n has been described above. Here, it can be said that the feature of this case is that the number to be divided in the division when calculating the average combustion rate is the previous manipulated variable MV _n-1.

Next, before explaining the minus-corrected average combustion rate calculation unit 33 and the plus-corrected average combustion rate calculation unit 34, the system having the largest average combustion rate and the system having the smallest average combustion rate will be described.
In the control cycle n, the largest family of average combustion rate (in the case of the first embodiment, i = 1 or 2) each strain i calculated by the average combustion rate calculating section 32 average burn rate Av_r ⁱ _n the The system i having the largest value is referred to as the system having the largest average combustion rate in the control cycle n. Conversely, the average combustion rate system i the average combustion rate Av_r ⁱ _n is the smallest value in the control cycle n most of small strains.
The average burn rate calculation unit 32, controls the cycle n, (in the first embodiment, i = 1 or 2) each strain from the average burn rate Av_r ⁱ _n of the largest system, and the average burn rate of the average burn rate The smallest strain of can be identified.
The system having the largest average combustion rate and the system having the smallest average combustion rate in the control cycle n may be specified by the average combustion rate determination unit 35 described later.

<Minus-corrected average combustion rate calculation unit 33>
The minus-corrected average combustion rate calculation unit 33 sets the average value obtained by subtracting the preset unit correction amount _Uad ^{from the previous operation amount MV 1} _{n-1 in the} system having the largest average combustion rate in the control cycle n. The minus-corrected average combustion rate, which is the value divided by the total maximum output steam amount of the system with the largest combustion rate, is calculated.
Specifically, in the control cycle n, for example, when the first system control unit 4A is the system having the largest average combustion rate, the minus-corrected average combustion rate calculation unit 33 is the first system control unit 4A in the control cycle n. The negatively corrected average combustion rate, which is the value obtained by subtracting the preset unit correction amount _Uad from the previous operation amount MV ¹ _{n-1 in the above,} and dividing by the total maximum output steam amount of the first system control unit 4A. to calculate the _minus Av_R ¹ _n. Specifically, it is represented by Equation 9.
Decreased exposure average burn rate of the first system control unit 4A _minus Av_r ¹ _n
= (MV ¹ _n-1- unit correction amount U _ad ) / total maximum output steam amount of the 1st system control unit 4A
(Equation 9)
Here, for the unit correction amount U _ad , for example, the unit vapor amount U may be applied. Further, the operating amount may be equivalent to 1% of the maximum combustion amount per boiler.

Similarly, in the control cycle n, for example, when the second system control unit 4B is the system having the largest average combustion rate, the minus-corrected average combustion rate calculation unit 33 is the previous time in the second system control unit 4B in the control cycle n. the subtracted value of the manipulated variable MV 2 _^n-1 preset unit correction amount U _ad from a minus correction average combustion rate is a value obtained by dividing the maximum output steam amount total value of the second system control unit 4B _minus Av_r ² _n is calculated. Specifically, it is represented by the formula 10.
Decreased exposure average burn rate of the second system control unit 4B _minus Av_r ² _n
= (MV ² _n-1- unit correction amount U _ad ) / total maximum output steam amount of the 2nd system control unit 4B
(Equation 10)

<Plus-corrected average combustion rate calculation unit 34>
Contrary to the negative correction calculation unit 313, the positive correction average combustion rate calculation unit 34 sets a unit correction amount preset ^{for the previous operation amount MV 1} _{n-1 in the system having the smallest average combustion rate in the control cycle n.} The plus-corrected average combustion rate, which is the value obtained by dividing the value obtained by adding U- _ad by the total maximum output steam amount of the system having the smallest average combustion rate, is calculated.
Specifically, in the control cycle n, for example, when the first system control unit 4A is the system having the smallest average combustion rate, the plus-corrected average combustion rate calculation unit 34 is the first system control unit 4A in the control cycle n. The value obtained by adding the preset unit correction amount _Uad from the previous operation amount MV ¹ _{n-1 in the above,} and dividing by the total maximum output steam amount of the first system control unit 4A, which is the plus correction average combustion rate. Calculate _plus Av_R ¹ _n. Specifically, it is represented by the formula 11.
Positive correction average combustion rate of 1st system control unit 4A _plus Av_R ¹ _n
= (MV ¹ _n-1 + unit correction amount U _ad ) / total maximum output steam amount of the 1st system control unit 4A
(Equation 11)

Similarly, in the control cycle n, for example, when the second system control unit 4B is the system having the smallest average combustion rate, the plus-corrected average combustion rate calculation unit 34 has the previous time in the second system control unit 4B in the control cycle n. of a preset unit correction amount value obtained by adding the U _ad from the operation amount MV 2 _^n-1, plus compensation average combustion rate is a value obtained by dividing the maximum output steam amount total value of the second system control unit 4B _plus Av_r Calculate ¹ _n. Specifically, it is represented by the formula 12.
Positive correction average combustion rate of 2nd system control unit 4B _plus Av_R ² _n
= (MV ² _n-1 + unit correction amount U _ad ) / total maximum output steam amount of the 2nd system control unit 4B
(Equation 12)

<Average combustion rate determination unit 35>
The average combustion rate determination unit 35 determines the deviation between the average combustion rate of the system having the largest average combustion rate and the average combustion rate of the system having the smallest average combustion rate in the control cycle n (for simplicity, "deviation of the average combustion rate". And the deviation between the negatively corrected average combustion rate of the system with the largest average combustion rate and the positively corrected average combustion rate of the system with the smallest average combustion rate (for simplicity, it is called "deviation of the corrected average combustion rate". ), It is determined whether or not the preset divergence condition is satisfied. The average combustion rate determination unit 35 determines that there is no deviation when the average combustion rates are the same.

<Differential conditions>
Here, some divergence conditions will be illustrated.
A condition in which both the deviation of the average combustion rate in the control cycle n and the deviation of the corrected average combustion rate are positive values may be set as a deviation condition (referred to as “deviation condition for each control cycle”).
Further, a threshold value L (L ≧ 1) for determination is set in advance, and the deviation of the average combustion rate and the corrected average in each control cycle n + i (0 ≦ i ≦ L) from the control cycle n to the control cycle n + L. A condition in which both the deviation of the combustion rate and the deviation are positive values may be set as a deviation condition (referred to as a deviation condition for a predetermined period).
Here, the threshold value L may be set so that the period from the control cycle n to the control cycle n + L is, for example, 10 seconds. In this case, the deviation of the average combustion rate and the deviation of the corrected average combustion rate both maintain positive values for 10 seconds.

<Operation amount correction unit 36>
When the operation amount correction unit 36 determines that the deviation condition is satisfied by the average combustion rate determination unit 35, the unit correction amount U _{ad is changed from the system control unit having the highest average combustion rate to the system control unit having the lowest average combustion rate.} To move.
Specifically, for example, when the deviation condition for each control cycle is applied as the deviation condition, in the control cycle n, the system control unit having the largest average combustion rate is the first system control unit 4A, and the system control unit has the smallest average combustion rate. When the system control unit is the second system control unit 4B, the previous operation amount MV ¹ _n-1 of the control cycle n in the first system control unit 4A is subtracted from the operation amount MV ¹ _n-1 by the unit correction amount U _ad. ^{In addition to correcting the value, the previous operation amount MV 2} _n-1 of the control cycle n in the second system control unit 4B is corrected to a value obtained by adding the unit correction amount U _ad to the operation amount MV ² _n-1. ^{Note that the change in required steam amount ΔMV 1} _n from the previous n-1 to this time n in the first system control unit 4A ^{and ΔMV 2} _n in the second system control unit 4B are not corrected.
By doing so, in the control cycle n, the unit correction amount _Uad can be moved ^{from the operation amount MV 1} _{n of the} first control unit to the operation amount MV ² _{n of the second system control unit 4B.} Further, due to this correction, the operation amount (MV ¹ _n + MV ² _n ) of the entire boiler system 1 does not change. Further, since the deviation related to the feedback control is not corrected at all, it does not affect the calculation of the deviation related to the feedback control in the next control cycle n + 1 or later, so that the feedback control in the control cycle after the next time is still consistent. Can be taken.
As a result, the average combustion rate correction control unit 30 is in a state where the combustion rate of the boiler group of one system is higher than the combustion rate of the boiler group of another system, and the negative correction average combustion of the boiler group having a high combustion rate. When the rate is higher than the positively corrected average combustion rate of the boiler group of another system, the operation amount can be corrected between the systems.

When a deviation condition for a predetermined period (from control cycle n to control cycle n + L) is applied as the deviation condition, the system control unit having the largest average combustion rate in the control cycle n + L is the first system control unit 4A and the average combustion rate. When the smallest system control unit is the second system control unit 4B, the previous operation amount MV ¹ _{n + L-1} of the control cycle n + L in the first system control unit 4A is changed from the operation amount MV ¹ _{n + L-1} to the unit correction amount U _ad. Is corrected to the value obtained by subtracting, and the previous operation amount MV ² _{n + L-1} of the control cycle n + L in the second system control unit 4B is corrected to the value obtained by adding the unit correction amount U _ad to the operation amount MV ² _{n + L-1.} .. ^{The required vapor amount change ΔMV 1} _{n + L} from the previous n + L-1 to this time n + L in the first system control unit 4A ^{and ΔMV 2} _{n + L} in the second system control unit 4B are not corrected.
By doing so, the control in the period n + L, it is possible to move the unit correction amount _{U ad} from the operation amount ^MV _{1 n + L} of the first system control unit 4A to the operation amount ^MV _{2 n + L} of the second system control unit 4B. Further, due to this correction, the operation amount (MV ¹ _{n + L} + MV ² _{n + L} ) of the entire boiler system 1 does not change. Further, since the deviation related to the feedback control is not corrected at all, it does not affect the calculation of the deviation related to the feedback control in the next control cycle n + L + 1 or later, so that the feedback control in the control cycle after the next time is still consistent. Can be taken.
As described above, when the dissociation condition is satisfied, the average combustion rate of the boiler group of each system can be leveled by repeating the correction of moving the _{unit correction amount Uad between different system boiler groups.}
As described above, when the divergence condition (particularly the divergence condition for a predetermined period) is satisfied, the combustion rate of the boiler group of one system is stable at a higher state than the combustion rate of the boiler group of another system. Even in this case, the average combustion rate correction control unit 30 moves a predetermined operation amount from the system with a high combustion rate to the system with a low combustion rate, so that the operation amount of the entire boiler system is not changed. In addition, it is possible to level the combustion rate of each system.
As a result, even if the boiler group of one system is started first to stabilize the steam load and then the boiler group of another system is started, the operation amount of the entire boiler system is not changed. In addition, by leveling the average combustion rate of each system, it is possible to secure the number of combustion units evenly to some extent in each system. As a result, even if the load increases or decreases suddenly, each system can follow it, and the control of all systems is stable.
Further, when the steam load is relatively high, for example, when all the boiler groups belonging to each system are burning, the boiler combustion rate of each system can be the same, so that the life of the boiler belonging to each system can be extended. Can be homogenized.
The unit correction amount _Uad may be dynamically changed. When changed, the determination of the deviation condition is applied to the control cycle after the _{unit correction amount Uad is changed.}

<About stopping the correction process by the average combustion rate correction control unit 30>
Further, when the combustion state of the boiler system 1 satisfies the following special conditions, it is preferable that the average combustion rate correction control unit 30 does not perform the correction process.
Specifically, in the boiler group of any system, the number control was stopped due to, for example, a failure (for example, sensor failure, communication failure, etc.), and in the case of manual operation of all units, the operation switch of all units was turned off. In this case, when the number control is restricted due to the case where the number of boilers during combustion is 0 or the like, the average combustion rate correction control unit 30 controls, for example, the average combustion rate correction control unit 30 so as not to perform the correction process. It can be stopped.
Further, if the steam amount cannot be output in the entire system, for example, if there is no steamable boiler, or if the header pressure value exceeds the control upper limit pressure, the control of the average combustion rate correction control unit 30 is stopped. be able to.
Further, when all the boilers belonging to the boiler group of any system are, for example, 97% combustion, the combustion of the destination to which the operation amount is moved so as not to perform the operation amount correction on the increasing side for the boiler group of the same system. State restrictions can be set.
On the contrary, when only one boiler belonging to the boiler group of any system is burning, for example, 20%, the operation amount is moved so as not to perform the operation amount correction on the decreasing side for the boiler group of the same system. Limitations can be set according to the original combustion state.
Next, the leveling of the number of combustion units and the boiler combustion rate of each system will be described.

<Leveling by changing the setting of unit control or turning off the operation>
The average combustion rate correction control is to level the average combustion rate in the boiler group of each system as described above. Here, the average combustion rate in the control cycle n is the operation amount (required steam amount) MV _n-1 in the previous n-1 of the boiler group divided by the total maximum steam amount of the number of controllable boilers in the current n. Is.
Therefore, if the number of controllable boilers included in the boiler group of each system is all burning, for example, and the number of combustion boilers (= number of controllable boilers) is different, the average combustion rate will be the same. When leveled to, the boiler combustion rate will be the same value, but the number of combustion units will deviate. In such a case, when you want to keep the same number of combustion boilers, for example, if you select the operation off boiler from the boiler group of the series with the larger number of combustion boilers so that the number of controllable units is the same. Good. Alternatively, by changing the setting of the number control, the number of units controlled may be reduced and a spare boiler may be provided. By doing so, the number of combustions in each system becomes the same, and the boiler combustion rate becomes almost the same.
Further, even if the average combustion rate of each system is the same value, for example, in the boiler group of one system, the number of combustion controllable units (for example, 5 units) is all burning. The boiler group of the other system is a case where the number of combustion controllable (for example, 5 units) includes a non-combustion boiler (for example, 1 unit), and the number of controllable boilers (5 of any system). When the total maximum steam amounts of the units) are the same, the combustion rate of the combustion boilers of the boiler group of one system may be lower than the combustion rate of the combustion boilers of the boiler group of the other system.
Even in such a case, in order to eliminate the deviation of the combustion rate of the combustion boiler, by applying the above-mentioned operation, the number of combustion units of each system can be made the same, and the deviation of the combustion rate of the combustion boiler can be eliminated. Can be done.

<Leveling by replacing control boilers according to priority>
If all the boilers are not burning when the steam load is low, the boiler combustion rate of each system may shift. For example, if the combustion rate of the burning boiler exceeds the first predetermined value, the number of burned units will increase by one, and if the combustion rate of the burning boiler falls below the second predetermined value, the number of burned units will decrease by one. / There is a condition for determining the reduction of units.
Under such conditions for determining whether to increase or decrease the number of units, for example, even if the number of units that can be controlled in each system is 5 and the total combustion rate (operation amount) is 200%, due to fluctuations in the steam load. In one system, 5 units x 40% combustion, and in the other system, 4 units x 50% combustion, and the number of combustion units and the boiler combustion rate may differ. In addition to fluctuations in steam load, for example, even when the boiler during combustion is turned off or the boiler that is being burned by manual operation is switched to automatic operation, the number of combustion units and the boiler combustion rate may differ. is there.
In such a case, as described above, even if the overall combustion rate (operation amount) of each system is 200%, one system burns 5 units x 40% and the other system burns 4 units x 50%. May be stable. In such a case, since the average combustion rate is obtained by dividing 200% by the total maximum output steam amount of the controllable boilers (5 units), it is determined that the average combustion rates match, and the operation amount is manipulated. The correction function of is not executed.
Then, there is a high possibility that the state in which the deviation of the boiler combustion rate is not eliminated will continue.
In such a case, for example, when the boiler priority is changed by performing rotation once a day, for example, the standby boiler whose priority has been raised forcibly starts combustion, so that the standby boiler In some cases, the number of combusted units becomes the same due to the combustion of. By changing the priority in this way, the number of combustion units in each system becomes the same, and the boiler combustion rate becomes almost the same.

The embodiment of the boiler system 1 has been described above based on the configuration of the boiler system 1. Next, the operation when the average combustion rate correction control according to the first embodiment is performed will be described.

Here, FIG. 4 is a diagram showing a processing flow related to the manipulated variable correction control executed for each control cycle. Specifically, step S1 is started to be executed every control cycle. At the start, the counter is initially set to 0.
Referring to FIG. 4, in step S1, the average combustion rate calculation unit 32 is the first system based on the operation amount in the first system control unit 4A and the second system control unit 4B acquired by the operation amount acquisition unit 31. The average combustion rate of the control unit 4A and the second system control unit 4B is calculated, and the system having the highest average combustion rate and the system having the lowest average combustion rate are specified.

In step S2, the average combustion rate determination unit 35 determines the deviation of the average combustion rate between the two systems (that is, the deviation between the average combustion rate of the system having the largest average combustion rate and the average combustion rate of the system having the smallest average combustion rate). ) Is calculated.

In step S3, the negatively corrected average combustion rate calculation unit 33 and the positively corrected average combustion rate calculation unit 34 have two systems of negatively corrected average combustion rates (that is, the negatively corrected average combustion rate of the system having the largest average combustion rate) and plus. The corrected average combustion rate (that is, the plus-corrected average combustion rate of the system having the smallest average combustion rate) is calculated.

In step S4, the average combustion rate determination unit 35 calculates the deviation of the corrected average combustion rate between the two systems (that is, the deviation between the minus-corrected average combustion rate and the plus-corrected average combustion rate).

In step S5, the average combustion rate determination unit 35 determines whether the deviation of the average combustion rate between the two systems and the deviation of the corrected average combustion rate are both the same positive value. If the values are the same (yes), the process proceeds to step S6. If the values are not the same (No), the process proceeds to step S8.

In step S6, it is determined whether or not the timer has reached a predetermined threshold value L or more. When the threshold value is L or more (in the case of Yes), the process proceeds to step S7. If it is less than the threshold value L (if No), the process proceeds to step S9.

In step S7, the operation amount correction unit 36 moves the unit correction amount between the two systems.

In step S8, the average combustion rate determination unit 35 resets the timer to 0. After that, the process proceeds to step S1.

In step S9, the average combustion rate determination unit 35 adds 1 to the timer. After that, the process proceeds to step S1.
As described above, the average combustion rate between the two systems can be leveled.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. Further, the effects described in the present embodiment merely list the most preferable effects arising from the present invention, and the effects according to the present invention are not limited to those described in the present embodiment.

<Boiler system with 3 or more boiler groups>
In the first embodiment, the boiler system including the two boiler groups has been described, but similarly, the boiler system including the boiler groups of three or more systems and the system control unit corresponding to each system is also described as follows. The configuration of the average combustion rate correction control unit can be applied.
Specifically, in the control cycle n, the average combustion rate is calculated for each boiler group of each system, and among those systems, the system having the highest average combustion rate and the system having the lowest average combustion rate are specified. .. Next, among those systems, for the system with the highest average combustion rate and the system with the lowest average combustion rate, the negative correction of the system with the highest average combustion rate and the plus of the system with the lowest average combustion rate, respectively. Calculate the corrected average combustion rate. The average combustion rate determination unit 35 determines the deviation (deviation of the average combustion rate) between the average combustion rate of the system having the largest average combustion rate and the average combustion rate of the system having the smallest average combustion rate in the control cycle n, and the average combustion rate. Whether or not a preset deviation condition is satisfied with respect to the deviation between the negatively corrected average combustion rate of the system with the largest average combustion rate and the positively corrected average combustion rate of the system with the smallest average combustion rate (deviation of the corrected average combustion rate). Is determined.
By doing so, when the average combustion rate determination unit 35 determines that the deviation condition is satisfied, the manipulated variable correction unit 36 changes from the system control unit having the highest average combustion rate to the system control unit having the lowest average combustion rate. The unit correction amount _Average can be moved.
As described above, when the divergence condition is satisfied between the system control unit having the highest average combustion rate and the system control unit having the lowest average combustion rate, the system control unit having the highest average combustion rate has the highest average combustion rate. _{By repeating the correction of moving the unit correction amount Uad} to a small system control unit, the average combustion rate of the boiler group of each system can be leveled.

<Separate equipment for the 1st system control unit and the 2nd system control unit>
In the first embodiment, the configuration in which the first system control unit 4A and the second system control unit 4B are included in the same control device has been described, but the present invention is not limited to this. For example, it may be made into a separate device by synchronizing the control cycles of the first system control unit 4A, the second system control unit 4B, and the average combustion rate correction control unit 30. Further, when it is assumed that each system control unit uses the same header pressure value of the steam header in the separate device, even if each system control unit uses the header pressure value measured by a different vapor pressure sensor. Good.
In addition, even when three or more system control units are provided, each system control unit can be made into a separate device in the same manner.

1 Boiler system 2 Boiler group 2A 1st boiler group 2B 2nd boiler group 20A, 20B Continuous control boiler 21A, 21B Boiler body 22A, 22B Local control unit 3 Number control device 30 Average combustion rate correction control unit 31 Operation amount acquisition unit 32 Average combustion rate calculation unit 33 Negative correction average combustion rate calculation unit 34 Plus correction average combustion rate calculation unit 35 Average combustion rate judgment unit 36 Operation amount correction unit 4A 1st system control unit 4B 2nd system control unit 411A, 411B Required steam amount Calculation unit 412A, 412B Output control unit 6 Steam header 7 Steam pressure sensor 11, 12 Steam pipe 13 Signal line 16A, 16B Signal line 18 Steam use equipment

Claims (6)

A group of boilers consisting of one or more boilers is provided with at least two systems.
A steam header that collects the steam generated by the boiler group of each system,
A steam pressure measuring means for measuring a header pressure value, which is a steam pressure value inside the steam header, and
A control unit provided for each boiler group of each system, and an operation amount related to combustion control of the boiler group of each system in the control cycle n so that the header pressure value matches a preset target pressure value. The required steam amount MVn is calculated by the speed type PI control or the speed type PID control method, and the control unit corresponding to the boiler group of each system that controls the combustion state of the boiler group of each system, respectively.
For the boiler group of each system, an average combustion rate correction control unit that corrects the operation amount related to combustion control of the boiler group, and
It is a boiler system equipped with
The average combustion rate correction control unit
It is possible to output to the control unit the previous operation amount MVn-1 of the control unit in the control cycle n, the identification information of the boiler whose number is controlled by the control unit, or the boiler whose number is controlled by the control unit. Maximum steam amount, operation amount acquisition unit to acquire, and
The maximum number of controllable boilers is the sum of the previous operation amount MVn-1 of the control unit and the maximum outputable steam amount of each of the number of controlled boilers in the control unit. An average combustion rate calculation unit that calculates the average combustion rate of the control unit in the control cycle n by dividing by the total amount of steam.
A value obtained by subtracting a preset unit correction amount from the previous operation amount MVn-1 of the control unit and dividing by the total maximum steam amount of the number of controllable boilers in the control unit. A minus-corrected average combustion rate calculation unit that calculates a certain minus-corrected average combustion rate,
Plus correction, which is the value obtained by adding the unit correction amount from the previous operation amount MVn-1 in the control unit to the control unit and dividing by the total maximum steam amount of the number controllable boilers in the control unit. A plus-corrected average combustion rate calculation unit that calculates the average combustion rate,
With respect to the first control unit which is the control unit having the largest average combustion rate and the second control unit which is the control unit having the smallest average combustion rate in the designated arbitrary control cycle n.
The average combustion rate deviation, which is the deviation between the average combustion rate of the first control unit and the average combustion rate of the second control unit, the negatively corrected average combustion rate of the first control unit, and the second With respect to the corrected average combustion rate deviation, which is the deviation from the positively corrected average combustion rate of the control unit, the average combustion rate determination unit that determines whether or not the preset deviation conditions are satisfied,
When the average combustion rate determination unit determines that the deviation condition is satisfied, the operation amount correction unit that moves the unit correction amount from the operation amount in the first control unit to the operation amount in the second control unit. When,
Boiler system with. The divergence condition is
In the control cycle n, the average combustion rate deviation between the first control unit and the second control unit and the corrected average combustion rate deviation are both positive values.
The manipulated variable correction unit
^{The previous manipulated variable MV 1} _n-1 of the control cycle n in the first control unit is corrected to a value obtained by subtracting the unit correction amount from the manipulated ^{variable MV 1} _{n-1, and in the second control unit.} By correcting the previous operation amount MV ² _n-1 of the control cycle n to a value obtained by adding the unit correction amount to the operation amount MV ² _{n-1, the operation of the first control unit is performed in the control cycle n.} The boiler system according to claim 1, wherein the unit correction amount is moved from the quantity MV ¹ _n ^{to the manipulated variable MV 2} _{n of the second control unit.} The divergence condition is
Regarding the first control unit and the second control unit
For the preset judgment counter value L (L ≧ 1)
In each control cycle n + i (0 ≦ i ≦ L) from the control cycle n to the control cycle n + L, the average combustion rate deviation between the first control unit and the second control unit, and the said. It is a condition that both the corrected average combustion rate deviations are positive values.
The manipulated variable correction unit
^{The previous operation amount MV 1} _{n + L-1} of the control cycle n + L in the first control unit is corrected to a value obtained by subtracting the unit correction amount from the operation amount MV ¹ _{n + L-1, and the second control unit.} controls the cycle n + previous operation amount ^MV _{2 n + L-1} L, is corrected to a value obtained by adding the unit correction amount to the manipulated variable ^MV _{2 n + L-1,} in the control cycle n + L in the first control unit The boiler system according to claim 1, wherein the unit correction amount is moved from the manipulated variable MV ¹ _{n + L of} the second control unit to the manipulated variable MV ² _{n + L of the second control unit.} The boiler system according to any one of claims 1 to 3, further comprising two boiler groups. The boiler system according to any one of claims 1 to 4, wherein the control unit and the average combustion rate correction control unit are included in one control device. The average combustion rate correction control unit further
The boiler system according to any one of claims 1 to 5, wherein the correction process related to the manipulated variable is not performed when the steam amount output cannot be performed in the entire system related to the boiler group.

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