JP6776767B2 - Boiler system - Google Patents

Description

The present invention provides a number control means (unit control device) for controlling the combustion amount of a boiler to be controlled so that the vapor pressure inside the steam collecting portion (hereinafter, also referred to as "steam header") falls within a set pressure range. Regarding the boiler system to be equipped.

In a boiler system composed of a boiler group consisting of a plurality of boilers, steam generated in the boiler group is collected in a steam header, and steam is supplied from this steam header to a load device. In such a boiler system, the combustion amount of the boiler to be controlled is controlled by the number control means (number control device) so that the pressure of steam (header pressure) in the steam header falls within the set pressure range.
In addition, each boiler has its own priority. The priority order is used to select a boiler that gives a combustion instruction, a combustion stop instruction, or the like.

Generally, when the boiler is operated for a long time, the water supply (can water) in the boiler is concentrated and carryover occurs, sediments such as sludge accumulate on the bottom of the can, the dryness of steam decreases, and valves are related. It causes damage to the equipment. Therefore, for example, when the time converted from the combustion time of the boiler as 100% combustion reaches a predetermined time, the operation switch of the boiler is turned off and the boiler water in the boiler body is discharged to the outside by a blow process ( It is necessary to perform all blow processing).
However, when the operation switch of the boiler is turned off, the output amount of the boiler becomes zero at once, so that the header pressure may become unstable due to a sudden decrease in the steam output amount.
Therefore, it is desirable that the boiler that performs the full blow treatment is a boiler that has stopped burning or is burning but has a smaller amount of combustion than other boilers.
Therefore, even if a plurality of boilers reach the time when all the blow processing is required at the same time, the number of units is such that the blow instruction signal is output only to one of them or the number of units that does not affect the steam supply amount. It is known to perform control (Patent Document 1).
In addition, the operation priority of boilers that require full blow processing has been changed to a lower level to reduce the need for boilers that require full blow processing to burn, thereby stopping the boiler. In some cases, it is known that the amount of steam supplied is not insufficient (Patent Document 2).

Japanese Unexamined Patent Publication No. 3-036403 Japanese Unexamined Patent Publication No. 2011-094823

However, even if the operation priority of boilers that require full blow processing is changed to a lower level, the number of boilers is controlled so as to increase the combustion amount of the boiler when the overall load increases. Therefore, it becomes difficult for the operator to stop the boiler.
Therefore, it is possible to reduce the combustion amount of the boiler that requires full blow processing, suppress the fluctuation amount of the output steam amount of the entire boiler when the operation switch is turned off, and suppress the instability of the header pressure. Control is desired.

INDUSTRIAL APPLICABILITY According to the present invention, the combustion amount of a boiler that requires full blow processing can be reduced, the fluctuation amount of the output steam amount of the entire boiler can be suppressed when the operation switch of the boiler is turned off, and the header pressure is unstable. The purpose is to provide a boiler system that can suppress becoming.

The present invention includes a boiler group composed of a plurality of boilers, a steam header for collecting the steam generated in the boiler group, a steam pressure measuring means for measuring a header pressure value which is a steam pressure inside the steam header, and a steam pressure measuring means. A boiler system including a control unit that controls the combustion state of the boiler group based on the header pressure value, wherein the control unit calculates the required steam amount based on the header pressure value. A unit, a combustion control unit that controls the output of the boiler group so as to generate the required amount of steam calculated by the required amount of steam calculation unit, and a blow notification of the boiler when it is time to completely blow. The blow notification alarm detection unit that detects the alarm, the lower priority that lowers the combustion priority of the blow notification boiler in which the blow notification alarm is detected to the lowest, and the upper limit of the combustion amount of the blow notification boiler are set in advance. The present invention relates to a boiler system including a limit setting unit for setting a first combustion amount.

Further, the first combustion amount is preferably the minimum combustion amount of the boiler.

Further, it is preferable that the lower priority order lowers the combustion priority of the blow notification boiler to the lowest level when the blow notification alarm is detected by the blow notification alarm detection unit.

Further, the lower priority order lowers the combustion priority of the blow notification boiler when the operator detects the confirmation operation of the blow notification alarm after the blow notification alarm is detected by the blow notification alarm detection unit. It is preferable to carry it down to.

Further, the lower priority order lowers the combustion priority of the blow notification boiler when the operator detects the confirmation operation of the blow notification alarm after the blow notification alarm is detected by the blow notification alarm detection unit. It is preferable to carry it down to.

Further, it is preferable that the control unit further includes a reset unit that cancels the setting by the limit setting unit when the required steam amount cannot be covered by the boiler group (required steam amount> maximum output steam amount).

Further, the control unit is a reset unit that cancels the setting by the limit setting unit when the burning boilers other than the blow notification boiler in the boiler group burn out of a predetermined combustion rate or a predetermined combustion range. It is preferable to further provide.

Further, the predetermined combustion rate is an eco-driving point which is a combustion rate at which the boiler efficiency of the boiler during combustion is highest, and the predetermined combustion range is such that the boiler efficiency of the boiler during combustion is equal to or less than a predetermined threshold value. It can be made into an eco-driving zone, which is a range of high combustion rates.

According to the present invention, it is possible to reduce the combustion amount of the boiler that requires all blow processing, suppress the fluctuation amount of the output steam amount of the entire boiler when the operation switch of the boiler is turned off, and reduce the header pressure. It is possible to suppress the instability.

It is a figure which shows the outline of the boiler system which concerns on one Embodiment of this invention. It is the schematic which shows the structure of the boiler of 1st Embodiment. It is a functional block diagram which shows the structure of the control part provided with the number control apparatus of 1st Embodiment. It is a flowchart which shows the process flow of the control part 4 which concerns on 1st Embodiment of this invention. It is a flowchart which shows the process flow of the control part 4 which concerns on 1st Embodiment of this invention.

[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.

As shown in FIG. 1, the boiler system 1 includes a boiler group 2 including a plurality of (5) boilers 20, a steam header 6 as a steam collecting part for collecting steam generated in the boiler 20, and a vapor pressure measurement. A vapor pressure sensor 7 as a means and a number control device 3 as a number control means are provided.
The boiler group 2 generates steam to be supplied to the steam-using equipment 18 as a load device.

The upstream side of the steam header 6 is connected to the boiler group 2 (each boiler 20) via a steam pipe 11. The downstream side of the steam header 6 is connected to the steam use facility 18 via the steam pipe 12. The steam header 6 adjusts the mutual pressure difference and pressure fluctuation of each boiler 20 by collecting and storing the steam generated in the boiler group 2, and supplies the steam with adjusted pressure to the steam use facility 18. It has become like.

The vapor pressure sensor 7 is electrically connected to the number control device 3 via the signal line 13. The vapor pressure sensor 7 measures the vapor pressure inside the steam header 6 (the pressure of the steam generated in the boiler group 2), and outputs a signal (vapor pressure signal) related to the measured vapor pressure via the signal line 13. It is transmitted to the control device 3.

The boiler system 1 is capable of supplying the steam generated by the boiler group 2 to the steam-using equipment 18 operated by the steam via the steam header 6.
The load (required load) required in the boiler system 1 is the amount of steam consumed in the steam-using equipment 18. When controlling the number of units, the fluctuation of the vapor pressure inside the steam header 6 that occurs in response to this steam consumption is calculated based on the vapor pressure (physical quantity) inside the steam header 6 measured by the steam pressure sensor 7. , The amount of combustion of each boiler 20 constituting the boiler group 2 is controlled.

If the required load increases due to the increase in the demand of the steam use facility 18 and the amount of supplied steam becomes insufficient, the vapor pressure inside the steam header 6 will decrease. On the other hand, if the required load decreases due to the decrease in the demand of the steam use equipment 18 and the amount of supplied steam becomes excessive, the vapor pressure inside the steam header 6 increases. Therefore, the fluctuation of the required load can be monitored by the vapor pressure signal from the vapor pressure sensor 7. The boiler system 1 is adapted to calculate a target steam amount according to the steam consumption amount (required load) of the steam use facility 18 based on this vapor pressure.

The number control device 3 includes a control unit 4 and a storage unit 5. Regarding the combustion control of the boiler group 2, the number control device 3 can change, for example, the setting conditions (priority order of the boiler, etc.) stored in the storage unit 5. The setting conditions may be set or changed manually in whole or in part, or in whole or in part automatically.

The boiler 20 is a step value control boiler or a continuous control boiler capable of burning at a plurality of stepwise combustion positions. The step value control boiler controls the amount of combustion by selectively turning on / off the combustion, adjusting the size of the flame, etc., and gradually changes the amount of combustion according to the selected combustion position. It is a boiler that can be increased or decreased. More specifically, the step value control boiler is N position control, that is, the combustion amount of the step value control boiler is stepwise to the N position including the combustion stop state, where N (≧ 3) is an arbitrary integer. A controllable boiler 20.

When five boilers 20 are used as step value control boilers, the combustion amount and combustion capacity (combustion amount in a high combustion state) at each combustion position may be set equally in each boiler 20. , Or it may be set differently.

Further, the boiler 20 can be replaced with a step value control boiler to be a continuous control boiler. Here, the continuous control boiler is a continuous control boiler capable of continuously changing the combustion rate and burning. For example, it is a boiler in which the combustion amount can be continuously controlled in a range from at least the minimum combustion state S1 (for example, the combustion state at a combustion amount of 20% of the maximum combustion rate) to the maximum combustion state S2. The continuous control boiler adjusts the combustion amount by controlling, for example, the opening degree (combustion ratio) of the valve that supplies fuel to the burner and the valve that supplies combustion air.

The continuous control boiler is controlled by turning on / off the combustion of the continuous control boiler (burner) for the change of the combustion state between the combustion stop state S0 and the minimum combustion state S1 of the continuous control boiler. Then, in the range from the minimum combustion state S1 to the maximum combustion state S2, the combustion amount can be continuously controlled.
Note that the continuous control of the combustion amount means that the operations and signals in the local control unit, which will be described later, are handled step by step as a digital method (for example, the output (combustion amount) of the continuous control boiler is in 1% increments. Even if it is controlled), it includes the case where the output can be controlled virtually continuously.

Priorities are set for each of the plurality of boilers 20. The priority order is used to select the boiler 20 that gives a combustion instruction, a combustion stop instruction, or the like. The priority can be set, for example, by using an integer value so that the smaller the numerical value, the higher the priority. The priority order is usually changed at predetermined time intervals (for example, 24 hour intervals) under the control of the control unit 4.
The number control device 3 does not forcibly burn each boiler 20 according to the priority, but burns the boiler 20 having a higher priority and burns the boiler 20 having a lower priority according to the priority according to the load fluctuation. It is equipped with an optimum combustion transition control function that naturally replaces the combustion boiler according to the priority by stopping it.

Each of the plurality of boilers 20 is electrically connected to the number control device 3 via the signal line 16, and the combustion position (combustion state) is controlled by the control of the number control device 3. Further, each of the plurality of boilers 20 can be separated from the control of the number control device 3 by the operation of the driver or automatically.

As shown in FIG. 2A, the boiler 20 described above includes a boiler main body 21 on which combustion is performed, and a local control unit 22 that controls the combustion position or combustion state of the boiler 20.

The local control unit 22 controls each boiler 20 and is capable of changing the combustion position or the combustion state according to the required load. The local control unit 22 controls each boiler 20 based on the number control signal by the control unit 4 at the time of unit control, while directly controlling the boiler 20 at the time of local control.
The local control unit 22 further includes a timer unit 221 and a blow notification alarm determination unit 222.
The timer unit 221 measures the integrated combustion time after discharging the boiler water until the boiler water level inside the boiler main body 21 becomes less than a predetermined value (after all blows). The integrated combustion time refers to the time obtained by converting the combustion time of the boiler 20 into the time for burning at a maximum combustion rate of 100%.

The blow notification alarm determination unit 222 determines whether or not the timed integrated combustion time exceeds a preset first time (referred to as “blow notification alarm”), and issues a blow notification alarm. When the determination is made, for example, a lamp (not shown) is turned on or a message is displayed on the display unit (not shown). By doing so, the operator can be informed that the time has reached when the boiler 20 needs a full blow.

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

Next, the details of the number control device 3 will be described.
The number control device 3 calculates the required combustion amount of the boiler group 2 according to the required load and the combustion state of each boiler 20 corresponding to the required combustion amount based on the steam pressure signal from the vapor pressure sensor 7, and each of them. The number control signal is transmitted to the boiler 20 (local control unit 22). As shown in FIG. 1, the number control device 3 includes a control unit 4 and a storage unit 5.

The control unit 4 controls the combustion state and priority of each boiler 20 by giving various instructions to each boiler 20 via the signal line 16 and receiving various data from each boiler 20. When each boiler 20 receives a signal for changing the combustion state from the control unit 4, the boiler 20 controls the boiler 20 according to the signal.
The detailed configuration of the control unit 4 will be described later.

The storage unit 5 sets the contents of instructions given to each boiler 20 under the control of the control unit 4, information such as the combustion state received from each boiler 20, the integrated combustion time, and the priority order of the plurality of boilers 20. Information, setting information related to priority change (rotation), etc. are stored.
Further, the storage unit 5 stores the total value of the output steam amount output from each boiler 20 and the output steam amount output from each boiler 20.

Next, the detailed configuration of the control unit 4 will be described. FIG. 2B is a block diagram showing a functional configuration of the control unit 4.
As shown in FIG. 2B, in order to reduce the amount of combustion of the boiler that requires full blow processing and to suppress the fluctuation amount of the output steam amount of the entire boiler group 2 when the operation switch is turned off, the control unit 4 is used. A required steam amount calculation unit 40, a combustion control unit 41, a blow notification alarm detection unit 42, a priority order lowering unit 43, a limit setting unit 44, and a reset unit 45 are included.

[Required steam amount calculation unit 40]
The required steam amount calculation unit 40 calculates the required steam amount based on the header pressure value measured by the vapor pressure sensor 7.
In the case of the boiler system 1 composed of the boiler group 2 composed of the plurality of step value control boilers 20, for example, the required steam amount calculation unit 40 is required depending on the pressure position of the header pressure value based on the known proportional distribution control method. Calculate the amount of steam.
Further, in the case of the boiler system 1 composed of the boiler group 2 composed of a plurality of continuous control boilers 20, for example, the required steam amount calculation unit 40 has a known position shape so that the header pressure value matches the target pressure value. Alternatively, the current required vapor amount MV _n is calculated by the velocity type PI algorithm or the PID algorithm.

[Combustion control unit 41]
The combustion control unit 41 controls the output of the boiler group 2 so as to generate the steam of the required steam amount calculated by the required steam amount calculation unit 40.
More specifically, the combustion control unit 41 sets the number of boilers 20 to be burned based on the required steam amount calculated by the required steam amount calculation unit 40. The combustion control unit 41 sets the boiler 20 for starting or stopping combustion according to the priority described in the storage unit 5, and also sends a number control signal (start of operation, operation) to the local control unit 22 of the boiler 20. Stop, and output the combustion rate or combustion position).
Further, the combustion control unit 41 controls combustion so that the combustion amount of the boiler whose upper limit value is set by the limit setting unit 44 described later is within the combustion amount of the upper limit value.

[Blow notification alarm detection unit 42]
The blow notification alarm detection unit 42 detects the boiler 20 at the time when all blows are required.
Specifically, for example, the blow notification alarm detection unit 42 receives a determination signal of the blow notification alarm of the boiler 20 from the local control unit 22 (blow notification alarm determination unit 222) of the boiler 20, so that all blows can be performed. Detect the boiler 20 when it is needed.

[Priority lowering 43]
The priority order lowering 43 lowers the combustion priority of the boiler 20 in which the blow notification alarm is detected by the blow notification alarm detection unit 42 to the lowest position in the boiler group 2.
More specifically, the priority priority lowering 43 lowers the combustion priority of the boiler (referred to as “blow notification boiler”) satisfying the preset blow notification boiler to the lowest rank in the boiler group 2.
Here, the blow notification condition is selected in advance from any of the following conditions 1 to 3 and set in the storage unit 5.
Condition 1: The blow notification alarm is output by the blow notification alarm determination unit 222 (that is, the blow notification alarm is detected by the blow notification alarm detection unit 42).
Condition 2: After the blow notification alarm is output by the blow notification alarm determination unit 222 (that is, after the blow notification alarm is detected by the blow notification alarm detection unit 42), the operator confirms the blow notification alarm (for example, a display screen). Or to detect the confirmation) input by the operator via the input unit.
Condition 3: After the blow notification alarm is output by the blow notification alarm determination unit 222 (that is, after the blow notification alarm is detected by the blow notification alarm detection unit 42), the operator gives an instruction to start the blow operation (for example, to each boiler 20). Detecting an operation in which the provided blow switch (not shown) is pressed by the operator).

[Limit setting unit 44]
The limit setting unit 44 sets the upper limit of the combustion amount of the blow notification boiler to a preset first combustion amount.
Here, the first combustion amount is set for each boiler 20 or for each boiler group, and is stored in the storage unit 5. The first combustion amount can be the minimum combustion amount of the blow notification boiler. For example, when the blow notification boiler is a step value control boiler, combustion at a low combustion position (referred to as "low combustion") can be set as the first combustion amount. When the blow notification boiler is a continuous control boiler, the minimum combustion state can be set as the first combustion amount.
Specifically, even when the limit setting unit 44 burns the blow notification boiler having the lowest priority within the first combustion amount, the boiler group 2 includes other blow notification boilers other than the blow notification boiler. The required steam amount calculated by the required steam amount calculation unit 40 by the combustion boiler can be covered (that is, the sum of the first combustion amount and the maximum output steam amount of other combustion boilers excluding the blow notification boiler is the required steam amount. If it is determined to exceed), the upper limit of the combustion amount of the blow notification boiler is set to the first combustion amount.
As described above, the combustion priority of the blow notification boiler is lowered to the lowest position in the boiler group 2 by the priority priority lowering 43, and the combustion amount of the blow notification boiler is the combustion of the upper limit value set by the limit setting unit 44. By controlling the combustion by the combustion control unit 41 so as to be within the amount (first combustion amount), for example, the required amount of steam can be covered only by the other combustion boiler 20 excluding the blow notification boiler in response to the load request. Occasionally, the combustion control unit 41 can stop combustion of the blow notification boiler by the optimum combustion transition control function.

The control of shifting the combustion amount of the blow notification boiler to the upper limit limit after the upper limit limit is set can be configured to immediately shift to the upper limit limit. Further, instead of immediately shifting to the upper limit limit, it may be configured to shift as shown below.
(Transition control part 1)
The control for shifting to the upper limit of the combustion amount of the blow notification boiler is configured to be gradually lowered over a predetermined time.
(Transition control part 2)
Blow notification Boiler combustion amount transition control to the upper limit limit, for example, immediately after setting the upper limit limit, allows the actual combustion amount to exceed the upper limit limit (for example, when the upper limit limit is set to low combustion, the upper limit limit Immediately after setting, even high combustion is permitted.) After the combustion amount of the blow notification boiler reaches the upper limit (for example, low combustion), the transition control is performed so that the upper limit is not exceeded.
For example, if a boiler burning with high combustion becomes a blow notification, the upper limit is set to "low combustion", and the combustion amount of the boiler is controlled to shift from high combustion to low combustion at once, the pressure becomes unstable due to a sudden decrease in the output steam amount. There is a possibility that
By applying the transition control 1 or the transition control 2, the above-mentioned risks can be avoided.

[Reset unit 45]
When the combustion amount of the blow notification boiler is controlled so as to be within the upper limit combustion amount (first combustion amount) set by the limit setting unit 44, the reset unit 45 receives the entire required load. As the number increases, the boiler group 2 cannot cover the required amount of combustion by other combustion boilers other than the blow notification boiler (that is, the first combustion amount and the maximum output steam amount of the other combustion boilers other than the blow notification boiler). When it is determined that the sum of the above is less than the required amount of steam), the limit (upper limit) of the amount of combustion of the blow notification boiler is temporarily removed.
By doing so, if the overall steam load increases after the upper limit of the combustion amount is set for the blow notification boiler and the required steam amount cannot be covered by the boiler group 2, the blow notification boiler is temporarily set. By resetting (removing) the set upper limit of the combustion amount, the output steam amount of the blow notification boiler can be increased, and the required steam amount can be output by the boiler group 2.
The reset of the upper limit of the combustion amount set in the blow notification boiler by the reset unit 45 is temporary. For example, since the standby boiler can be activated to generate the amount of steam, even when the combustion amount of the blow notification boiler is burned within the first combustion amount, it is necessary by the boiler group 2. When the required steam amount calculated by the steam amount calculation unit 40 can be covered, the limit setting unit 44 again sets the upper limit (first combustion amount) of the combustion amount of the blow notification boiler.
By doing so, when the upper limit of the combustion amount of the blow notification boiler is temporarily reset (removed), after the reset, for example, by burning the standby boiler, the blow notification boiler is burned within the first combustion amount. Even in such a case, if the boiler group 2 can cover the required steam amount calculated by the required steam amount calculation unit 40 by other combustion boilers other than the blow notification boiler, the combustion amount of the blow notification boiler is again. The upper limit (first combustion amount) of can be set.

[Processing flow of control unit 4]
Next, a series of flow of control by the number control device 3 (control unit 4) in the first embodiment will be described with reference to FIGS. 3 and 4. 3 and 4 are flowcharts showing the processing contents of the control unit 4.

The processing contents of the number control device 3 (control unit 4) are shown with reference to FIGS. 3 and 4.
It is assumed that the number of each boiler 20 included in the boiler group 2 is controlled by the number control device 3 (control unit 4).
The processing flow related to the blow notification boiler will be described with reference to FIGS. 3 and 4.
In this processing flow, it is assumed that condition 2 is preset as a blow notification condition. That is, when the control unit 4 detects a blow notification alarm confirmation operation by the operator after the blow notification alarm determination unit 222 outputs the blow notification alarm (condition 2), the control unit 4 lowers the priority order.

In step ST1, the control unit 4 (blow notification alarm detection unit 42) detects for each boiler 20 whether or not it is time to perform all blows (that is, whether or not there is a blow notification alarm). If the blow notification alarm is not detected for each boiler 20 (No), the process returns to step ST1. When a blow notification alarm of a certain boiler 20 (hereinafter referred to as "boiler 20A") is detected (Yes), the process proceeds to step ST2.

In step ST2, the control unit 4 (blow notification alarm detection unit 42) determines whether or not the operator has detected the blow notification alarm confirmation operation. When the operator detects the operation of confirming the blow notification alarm (Yes), the process proceeds to step ST3. If the operator does not detect the blow notification alarm confirmation operation (No), the process returns to step ST2.

In step ST3, the control unit 4 (priority transfer lower part 43) lowers the combustion priority of the boiler 20A to the lowest position in the boiler group 2.

In step ST4, even if the control unit 4 (limit setting unit 44) burns the boiler 20A within the first combustion amount, the boiler group 2 requires the amount of steam required by other combustion boilers other than the boiler 20A. It is determined whether or not the required amount of steam calculated by the calculation unit 40 can be covered. If it is determined that the required amount of steam can be covered (Yes), the process proceeds to step ST5. If it is determined that the required amount of steam cannot be covered (No), the process returns to step ST4.

In step ST5, the control unit 4 (limit setting unit 44) sets the upper limit of the combustion amount of the boiler 20A to the first combustion amount.

In step ST6, even when the boiler 20A is burned within the first combustion amount, the control unit 4 (reset unit 45) calculates the required steam amount by the other combustion boilers other than the boiler 20A in the boiler group 2. It is determined whether or not the required amount of steam calculated by the unit 40 can be covered. If it is determined that the required amount of steam can be covered, the process proceeds to step ST8. If it is determined that the required amount of steam cannot be covered (No), the process proceeds to step ST7.

In step ST7, the control unit 4 (reset unit 45) resets the upper limit (first combustion amount) of the combustion amount of the boiler 20A. After that, the process returns to step ST4.

In step ST8, it is determined whether or not the boiler 20A has been stopped from burning by the optimum combustion transition control function of the control unit 4. When the boiler 20A is stopped burning (Yes), the process proceeds to step ST9. If the boiler 20A has not been stopped from burning (No), the process returns to step ST6.

In step ST9, the boiler 20A can be fully blown.

In this way, if the steam load of the entire boiler group 2 becomes low without actively stopping the combustion of the boiler 20A, the boiler 20A can be stopped by the optimum combustion transition control function. As a result, the entire blow process of the boiler 20A becomes possible.

The processing flow of the number control device 4 (control unit 40) is not limited to the above.
[Modification example 1 of processing flow]
In the above-mentioned processing flow, it is determined in step ST8 whether or not the boiler 20A has been stopped from burning by the optimum combustion transition control function, and if the boiler 20A is stopped from burning, the process proceeds to step ST9.
On the other hand, in the optimum combustion transition control function, there is a possibility that the boiler 20A does not stop easily. Therefore, instead of stopping the combustion by the optimum combustion transition control function, step ST8 is changed to the next step ST8'. , Step ST9 may be replaced with step ST9'.
In step ST8', whether or not the combustion rate of the boiler 20A has reached the minimum combustion rate, and the boiler group 2 needs to be calculated by the required steam amount calculation unit 40 by another combustion boiler even if the boiler 20A is stopped. It is determined whether or not the amount of steam can be covered, and if these conditions are satisfied (Yes), the process proceeds to step ST9', and if these conditions are not satisfied (No), the process returns to step ST6.
In step ST9', the boiler 20A is stopped from burning, and the boiler 20A can be fully blown.

[Modification example 2 of processing flow]
In the above-described processing flow and its modification 1, priority is given to the case where the blow notification alarm detection unit 42 detects the blow notification alarm for the boiler 20 and then the operator detects the blow notification alarm confirmation operation (condition 2). The order was to be moved down, but instead of condition 2, condition 1 (unconditionally lowering the priority due to the detection of the blow notification alarm) or condition 3 (when the operator detects the operation of the blow operation start instruction). ) Can be applied.

When condition 1 is applied, the above-mentioned processing flow and the processing in step ST2 of the modification 1 thereof become unnecessary.

When the condition 3 is applied, the above-described processing flow and step ST2 of the modification 1 thereof are replaced with the next step ST2'.
In step ST2', the control unit 4 (blow notification alarm detection unit 42) determines whether or not the operation of the blow operation start instruction by the operator has been detected. When the confirmation operation of the blow operation start instruction by the operator is detected (Yes), the process proceeds to step ST3. If the confirmation operation of the blow operation start instruction by the operator is not detected (No), the process returns to step ST2'.

According to the boiler system 1 of the first embodiment described above, the following effects are obtained.

The number control device 3 (control unit 4) according to the boiler system 1 of the first embodiment has a blow notification alarm detection unit 42 that detects a blow notification alarm of the boiler when all blows are required, and a blow notification alarm. The lower priority 43 that lowers the combustion priority of the blow notification boiler that outputs the above to the lowest, and the limit setting unit 44 that sets the upper limit of the combustion amount of the blow notification boiler to the preset first combustion amount. including.
As a result, when the overall steam load is low, the number control device 3 (control unit 4) can stop the blow notification boiler due to the outcome of the optimum combustion transition control function or the like. Further, for example, when the operation switch is turned off by the operator, even when the blow notification boiler is stopped, the balance between the output steam amount and the steam load is lost, and the header pressure is prevented from becoming unstable. be able to.

The number control device 3 (control unit 4) according to the boiler system 1 of the first embodiment is a reset unit that temporarily releases the setting by the limit setting unit 44 when the required steam amount cannot be covered by the boiler group 2. 45 is further provided.
As a result, when the overall steam load increases after the upper limit of the combustion amount is set for the blow notification boiler and the required steam amount cannot be covered by the boiler group 2, the blow notification boiler is temporarily set. By resetting (removing) the upper limit of the burned amount, the output steam amount of the blow notification boiler can be increased, and the required steam amount can be output in the boiler group 2.

Although the preferred first embodiment of the boiler system of the present invention has been described above, the present invention is not limited to the above-described embodiment and can be appropriately modified.

[Modification 1]
In the first embodiment, when the total steam load increases after the upper limit of the combustion amount is set by the limit setting unit 44 for the blow notification boiler and the boiler group 2 cannot cover the required steam amount, it is reset. The unit 45 is configured to temporarily reset (remove) the upper limit of the combustion amount set in the blow notification boiler.
On the other hand, from the viewpoint of emphasizing the boiler efficiency, after the upper limit of the combustion amount is set for the blow notification boiler by the limit setting unit 44, the burning boiler 20 excluding the blow notification boiler in the boiler group 2 is predetermined. When burning out of the combustion rate or the predetermined combustion range, the reset unit 45 may be configured to temporarily reset (remove) the upper limit of the combustion amount set in the blow notification boiler.

As a predetermined combustion rate, it is preferable to apply an eco-driving point, which is a combustion rate at which the boiler efficiency of the combustion boiler is highest. Further, as a predetermined combustion range, it is preferable to apply an eco-driving zone which is a range of a combustion rate in which the boiler efficiency of the combustion boiler becomes higher than a predetermined threshold value.
By doing so, when the upper limit of the combustion amount is set for the blow notification boiler by the limit setting unit 44, and then another combustion boiler burns outside the eco-driving point or the eco-driving zone (that is, the combustion boiler). It is possible to burn other combustion boilers at the eco-driving point or eco-driving zone by temporarily resetting (removing) the upper limit of the amount of combustion set in the blow notification boiler (when the boiler efficiency drops). And.
In this way, the boiler efficiency of the combustion boiler can be prioritized over the entire blow processing of the blow notification boiler.

When the boiler efficiency of the combustion boiler is prioritized over the entire blow processing of the blow notification boiler, a flowchart showing the processing contents by the number control device 3 (control unit 4) shown in FIG. 3 (and modification 1 and modification 2 of the flowchart) ) Can be explained by replacing step ST4 with step ST4'and step ST6 with step ST6'.

[Step ST4']
In step ST4', when the control unit 4 (limit setting unit 44) burns the boiler 20A within the first combustion amount, in the boiler group 2, the other combustion boilers other than the boiler 20A are eco-driving points or eco. Determine whether or not to burn without leaving the operation zone. When it is determined that another combustion boiler burns without departing from the eco-driving point or the eco-driving zone (Yes), the process proceeds to step ST6'. If it is determined that another combustion boiler burns outside the eco-driving point or the eco-driving zone (No), the process returns to step ST4'.

[Step ST6']
In step ST6', the control unit 4 (reset unit 45) determines whether or not the other combustion boilers other than the boiler 20A burn without departing from the eco-driving point or the eco-driving zone. When it is determined that another combustion boiler burns without departing from the eco-driving point or the eco-driving zone (Yes), the process proceeds to step ST8. If it is determined that another combustion boiler burns outside the eco-driving point or the eco-driving zone (No), the process proceeds to step ST7.
As a result, when another combustion boiler burns out of the eco-driving zone after the upper limit of the combustion amount is set for the blow notification boiler, the upper limit of the combustion amount temporarily set for the blow notification boiler is set. Boiler efficiency can be prioritized by resetting (removing).

In the first to second embodiments, the present invention is applied to the boiler system 1 including the boiler group 2 composed of five boilers 20, but the present invention is not limited to this. That is, the present invention may be applied to a boiler system including a boiler group consisting of 6 or more boilers 20, or may be applied to a boiler system including a boiler group consisting of 2 to 4 boilers. ..

In the first to second embodiments, when the boiler 20 is a continuously controlled boiler, they all have the same boiler capacity, but the present invention is not limited to this. That is, it can be applied even when the minimum combustion amount, the unit steam amount, and the combustion capacity as the maximum combustion amount are different for each continuous control boiler.

In the first to second embodiments, when the boiler 20 is a step value control boiler, it may have a combustion position at an arbitrary N position.

Further, when the boiler is configured with a step value control boiler, the boiler capacity, the number of steps N of the combustion position, the combustion rate at each combustion position, and the like may be different for each step value boiler.

1 Boiler system 2 Boiler group 3 Number control device 4 Control unit 40 Required steam amount calculation unit 41 Combustion control unit 42 Blow notification alarm detection unit 43 Priority lowering 44 Limit setting unit 45 Reset unit 5 Storage unit 6 Steam header (steam set) Department)
7 Vapor pressure sensor (Vapor pressure measuring means)
18 Steam use equipment (load equipment)
20 boiler

Claims (8)

A group of boilers consisting of multiple boilers and
A steam header that collects the steam generated in the boiler group,
A vapor pressure measuring means for measuring a header pressure value, which is the vapor pressure inside the steam header, and
A control unit that controls the combustion state of the boiler group based on the header pressure value,
It is a boiler system equipped with
The control unit
A required steam amount calculation unit that calculates the required steam amount based on the header pressure value, and
A combustion control unit that controls the output of the boiler group so as to generate steam of the required steam amount calculated by the required steam amount calculation unit.
A blow notification alarm detection unit that detects the blow notification alarm of the boiler when all blows are required, and
The lower priority of lowering the combustion priority of the blow notification boiler in which the blow notification alarm is detected to the lowest, and
A boiler system including a limit setting unit that sets an upper limit of the combustion amount of the blow notification boiler to a preset first combustion amount. The boiler system according to claim 1, wherein the first combustion amount is the minimum combustion amount of the boiler. The lower priority is
The boiler system according to claim 1 or 2, wherein when the blow notification alarm detection unit detects a blow notification alarm, the combustion priority of the blow notification boiler is lowered to the lowest level. The lower priority is
Claim 1 or claim that the combustion priority of the blow notification boiler is lowered to the lowest level when the operator detects the confirmation operation of the blow notification alarm after the blow notification alarm is detected by the blow notification alarm detection unit. The boiler system according to 2. The lower priority is
Claim 1 or claim 2 in which the combustion priority of the blow notification boiler is lowered to the lowest level when the operator detects an operation of a blow operation start instruction after the blow notification alarm is detected by the blow notification alarm detection unit. Boiler system described in. The control unit
The boiler system according to any one of claims 1 to 5, further comprising a reset unit for canceling the setting by the limit setting unit when the required steam amount cannot be covered by the boiler group. The control unit
Claim 1 further includes a reset unit for canceling the setting by the limit setting unit when a burning boiler other than the blow notification boiler in the boiler group burns outside a predetermined combustion rate or a predetermined combustion range. The boiler system according to any one of claims 5. The predetermined combustion rate is an eco-driving point which is a combustion rate at which the boiler efficiency of the boiler during combustion is highest.
The boiler system according to claim 7, wherein the predetermined combustion range is an eco-driving zone in which the boiler efficiency of the boiler during combustion is higher than a predetermined threshold value.

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