JP2014055750A - Boiler system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boiler system showing a superior stability in supplying steam and followability to variation of required load.SOLUTION: This boiler system includes a boiler 20 capable of performing a stage value combustion control for changing combustion amount gradually and a continuous combustion control for continuously changing combustion amount and a control part for carrying out the stage value combustion control and/or continuous combustion control against the boiler 20 to change a combustion amount and then a range between the adjoining stage combustion positions is defined as a stage combustion unit. In the case that one or more stage combustion units B1 to B5 are found between a combustion amount after changing and a combustion amount before changing, changing of the combustion amount at the stage combustion units B1 to B5 including all is carried out by the stage value combustion control, changing of the combustion amount at the stage combustion units B1 to B5 including no all is carried out by the stage value combustion control, and changing of the combustion amount is carried out only by the continuous combustion control in the case that any of the stage combustion units B1 to B5 is not included between the combustion amount after the changing and the combustion amount before the combustion amount.

Description

  The present invention relates to a boiler system including a boiler and a control unit that changes a combustion amount of the boiler.

  2. Description of the Related Art Conventionally, a boiler system including a boiler capable of phase value combustion control that changes the combustion amount in stages and a boiler system including a boiler capable of continuous combustion control that continuously changes the combustion amount are known ( For example, see Patent Document 1 below). In a boiler system, it is required to satisfy both the stability of supply of steam and the followability to fluctuations in required load.

JP 2012-17965 A

  The stability of the supply of steam is superior in a boiler system including a boiler capable of continuous combustion control in that the unit (step) for changing the combustion amount is small. On the other hand, the followability (responsiveness) with respect to fluctuations in required load is superior in a boiler system including a boiler capable of step value combustion control in that the amount of combustion is less changed. There is a demand for further compatibility between the stability of the supply of steam and the ability to follow fluctuations in the required load.

  Accordingly, an object of the present invention is to provide a boiler system that is excellent in the stability of supply of steam and the ability to follow fluctuations in required load.

  The present invention can perform step value combustion control in which the combustion amount is changed in stages by performing combustion at a plurality of stepwise stage combustion positions, and continuous combustion control in which the combustion amount is continuously changed is possible. A boiler, and a control unit that changes the combustion amount by performing the stage value combustion control and / or the continuous combustion control on the boiler, and a range between adjacent stage combustion positions is a stage combustion unit. In the specified boiler system, the control unit includes the whole of the staged combustion unit when at least one of the stage combustion units is included between the changed combustion amount and the changed combustion amount. The combustion amount in the stage combustion unit is changed by the stage value combustion control, the combustion amount in the stage combustion unit that is not included in the whole is changed by the continuous combustion control, and the changed combustion amount is changed. Previous combustion The step when the whole of the combustion unit is not included One relates boiler system carried out by only the continuous combustion control changes the combustion amount between.

  In addition, the present invention can perform step value combustion control in which the combustion amount is changed in stages by performing combustion at a plurality of stepwise stage combustion positions, and continuous combustion control in which the combustion amount is continuously changed is possible. And a control unit that changes the combustion amount by performing the stage value combustion control and / or the continuous combustion control on the boiler, and the range between the adjacent stage combustion positions is stage combustion. The boiler system is defined as a unit, and when the changed combustion amount coincides with the stage combustion position, the control unit changes the combustion amount only by the stage value combustion control. When the subsequent combustion amount does not coincide with the stage combustion position and the stage combustion unit including the changed combustion amount is the same as the stage combustion unit including the combustion amount before the change, the change of the combustion amount is performed. The continuous combustion control only And when the changed combustion amount does not coincide with the stage combustion position and the stage combustion unit including the changed combustion amount is different from the stage combustion unit including the combustion amount before the change. The change in the combustion amount in the stage combustion unit not including the changed combustion amount is performed by the step value combustion control, and the change in the combustion amount in the stage combustion unit including the changed combustion amount is performed in the continuous combustion. It is related with the boiler system performed by control.

  The boiler has a burner that performs combustion, and the step value combustion control is performed by changing the amount of air supplied to the burner step by step, and the continuous combustion control is supplied to the burner. Preferably, this is done by continuously changing the amount of air to be produced.

  According to the boiler system of the present invention, it is possible to provide a boiler system that is excellent in the stability of supply of steam and the ability to follow changes in required load.

It is a figure showing the outline of the boiler system concerning a 1st embodiment of the present invention. It is a figure which shows the combustion position and virtual boiler of the boiler which concerns on 1st Embodiment of this invention. It is a figure which shows the 1st example of transfer of the combustion pattern of the boiler which concerns on 1st Embodiment of this invention. It is a figure which shows the 2nd example of transfer of the combustion pattern of the boiler which concerns on 1st Embodiment of this invention. It is a figure which shows the 3rd example of transfer of the combustion pattern of the boiler which concerns on 1st Embodiment of this invention. It is a flowchart which shows the combustion control of the boiler system which concerns on 1st Embodiment of this invention. It is a figure which shows the 1st example of transfer of the combustion pattern of the boiler which concerns on 2nd Embodiment of this invention. It is a figure which shows the 2nd example of transfer of the combustion pattern of the boiler which concerns on 2nd Embodiment of this invention. It is a figure which shows the 3rd example of transfer of the combustion pattern of the boiler which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the combustion control of the boiler system which concerns on 2nd Embodiment of this invention.

<First Embodiment>
Hereinafter, a first embodiment of a boiler system of the present invention will be described with reference to the drawings. First, the whole structure of the boiler system 1 of this invention is demonstrated, referring FIG. FIG. 1 is a diagram showing an outline of a boiler system according to a first embodiment of the present invention. As shown in FIG. 1, the boiler system 1 includes a boiler group 2 including a plurality (three) of boilers 20, a steam header 6 that collects steam generated in the plurality of boilers 20, and the steam header 6. A vapor pressure sensor 7 for measuring the internal pressure and a number control device 3 having a control unit 4 for controlling the combustion state of the boiler group 2 are provided.

The boiler group 2 produces | generates the vapor | steam supplied to the steam use installation 18 as a load apparatus.
The steam header 6 is connected to a plurality of boilers 20 constituting the boiler group 2 via a steam pipe 11. A downstream side of the steam header 6 is connected to a steam use facility 18 via a steam pipe 12. The steam header 6 collects and stores the steam generated in the boiler group 2, thereby adjusting the pressure difference and pressure fluctuation of the plurality of boilers 20, and supplying the steam whose pressure is adjusted to the steam using facility 18. Supply.

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

  The number control device 3 is electrically connected to the plurality of boilers 20 through the signal line 16. The number control device 3 controls the combustion state of each boiler 20 based on the steam pressure inside the steam header 6 measured by the steam pressure sensor 7.

  The above boiler system 1 can supply the steam generated in the boiler group 2 to the steam using equipment 18 via the steam header 6. The load required in the boiler system 1 (required load) is the amount of steam consumed in the steam using facility 18. The number control device 3 determines the fluctuation of the steam pressure inside the steam header 6 corresponding to the fluctuation of the steam consumption based on the steam pressure (physical quantity) inside the steam header 6 measured by the steam pressure sensor 7. The amount of combustion of each boiler 20 which comprises the boiler group 2 is calculated and controlled.

  Specifically, the demand load (steam consumption) increases due to an increase in demand for the steam use facility 18, and if the supply steam quantity is insufficient, the steam pressure inside the steam header 6 decreases. On the other hand, if the demand load (steam consumption) decreases due to a decrease in the demand of the steam use facility 18, and the supply steam amount becomes excessive, the steam pressure inside the steam header 6 increases. Therefore, the boiler system 1 can monitor the fluctuation of the required load based on the fluctuation of the vapor pressure measured by the vapor pressure sensor 7. Then, the boiler system 1 calculates a target evaporation amount corresponding to the consumed steam amount (required load) of the steam using facility 18 based on the steam pressure of the steam header 6.

  Next, the combustion position (combustion state, amount of combustion) of the boiler 20 which comprises the boiler system 1 of 1st Embodiment, a virtual boiler, etc. are demonstrated. FIG. 2 is a diagram illustrating a combustion position of the boiler and the virtual boiler according to the first embodiment of the present invention.

The boiler 20 of the present embodiment can perform step value combustion control and continuous combustion control.
The step value combustion control is a control in which combustion is performed at a plurality of stepwise stage combustion positions and the amount of combustion is changed stepwise. For example, combustion is selectively turned on / off or the size of the flame is stepped. The amount of combustion is controlled stepwise by adjusting the amount of combustion or the like, and the amount of combustion is increased or decreased stepwise according to the selected step combustion position.

  The continuous combustion control is a control for continuously changing the combustion amount, and more specifically, 0% (no combustion) to 100% (maximum combustion amount) with respect to the combustion capacity (combustion amount in the maximum combustion state). In this range, the combustion amount is continuously changed.

  It should be noted that the continuous change of the combustion amount in the continuous combustion control includes not only the case where the combustion amount is controlled without permission, but also the case where calculations and signals in the control unit are digitally handled in stages. Even so, for example, the control amount of the combustion amount is set to a smaller value (for example, 1% or less) than the fluctuation of the combustion amount due to variations in combustion air, fuel, etc., and is changed continuously in practice. Shall be included.

  As shown in FIG. 2, the boiler 20 includes a combustion stop position P0 (0%), a first combustion position P1 (20%), a second combustion position P2 (30%), a third combustion position P3 (50%), So-called six-position control is made possible so that combustion is possible at six combustion positions (P0 to P5) of the fourth combustion position P4 (80%) and the fifth combustion position P5 (100%).

  The N position control represents that the combustion amount of the step value control boiler can be controlled step by step to the N position including the combustion stop position. The number of combustion positions may be three positions (combustion stop position, low combustion position, and high combustion position), four positions (combustion stop position, low combustion position, medium combustion position, and high combustion position).

The 6-position control boiler 20 can be understood as being composed of five virtual boilers (first virtual boiler to fifth virtual boiler). In the virtual boiler, differences in combustion position (combustion amount) in the boiler (low combustion position, medium combustion position, high combustion position, etc.) are regarded as independent boilers, and the respective evaporation amounts are virtually assumed in the boiler. For example, in the case of an on / off boiler (two-position boiler), there is one virtual boiler, which matches the actual number of physical boilers. Further, even if the three-position boiler is physically one unit, it can be virtually counted as two units of a low combustion amount boiler and a (high combustion amount-low combustion amount) boiler. The four-position boiler can be virtually counted as a low combustion amount boiler, a (medium combustion amount-low combustion amount) boiler, and a (high combustion amount-medium combustion amount) boiler.
For example, if a three-position boiler is in a low combustion state, it can be handled for control if a combustion instruction is given to the low combustion amount boiler, while the (high combustion amount-low combustion amount) boiler On the other hand, if a combustion stop instruction is given, it can be handled in terms of control.

  When the combustion capacity of the boiler 20 (combustion amount in the maximum combustion state) is 100%, the combustion capacity of the first virtual boiler is 20% (first combustion position P1 (20%) − combustion stop position P0 (0%)). ), The combustion capacity of the second virtual boiler is 10% (second combustion position P2 (30%) − first combustion position P1 (20%)), and the combustion capacity of the third virtual boiler is 20% (first 3 combustion position P3 (50%)-second combustion position P2 (30%)), and the combustion capacity of the fourth virtual boiler is 30% (fourth combustion position P4 (80%)-third combustion position P3 (50 %)), The combustion capacity of the fifth virtual boiler is 20% (fifth combustion position P5 (100%) − fourth combustion position P4 (80%)).

  The combustion amount at each combustion position of the boiler 20 is set so as to generate an amount of steam corresponding to the pressure difference of the steam pressure in the steam header 6 to be controlled. In the three boilers 20, the combustion amount and the combustion capacity at each combustion position, and the virtual boiler may be set equally or differently.

  In the boiler group 2, a plurality of combustion patterns are set that are combinations of the boilers 20 and their combustion positions (or combinations of virtual boilers). The combustion pattern is selected such that the smaller the required load, that is, the higher the vapor pressure detected by the vapor pressure sensor 7, the smaller the combustion amount. Further, a pattern in which the combustion amount increases as the required load increases, that is, as the vapor pressure decreases, is selected.

The control unit 4 performs step value combustion control and / or continuous combustion control on the boiler 20 to change the combustion amount. In the case where one or more whole stage combustion units (ranges between adjacent stage combustion positions) are included between the changed combustion amount and the changed combustion amount, the control unit 4 The change of the combustion amount in the included stage combustion unit is performed by the stage value combustion control, and the change of the combustion amount in the stage combustion unit not including the whole is performed by the continuous combustion control. On the other hand, the control unit 4 changes the combustion amount only by the continuous combustion control when none of the entire stage combustion unit is included between the changed combustion amount and the changed combustion amount. When the virtual boiler concept is used, each virtual boiler and the staged combustion unit coincide.
Details of the control will be described in detail with reference to a flowchart described later.

Next, the specific structure of the several boiler 20 by the boiler system 1 of this embodiment is demonstrated.
Based on the vapor pressure signal from the vapor pressure sensor 7, the number control device 3 calculates the required combustion amount of the boiler group 2 according to the required load and the combustion position (combustion state) of each boiler 20 corresponding to the required combustion amount. Then, the number control signal is transmitted to each boiler 20 (local control unit 25 described later). As shown in FIG. 1, the number control device 3 includes a storage unit 5 and a control unit 4.

  The storage unit 5 includes information such as the contents of instructions given to each boiler 20 under the control of the number control device 3 (control unit 4), the combustion state (combustion position) received from each boiler 20, and a plurality of boilers. Information on the setting conditions of the 20 combustion patterns, information on setting priority of the plurality of boilers 20, information on setting on changing priority (rotation), and the like are stored.

  The control unit 4 gives various instructions to the boilers 20 through the signal lines 16 and receives various data from the boilers 20 to determine the combustion states (combustion positions) and priority of the three boilers 20. Control the ranking. When each boiler 20 receives a signal for changing the combustion position from the number control device 3, it controls the boiler 20 according to the instruction.

  As shown in FIG. 1, the boiler 20 controls a boiler body 21 in which combustion is performed, a local vapor pressure measurement unit 27 that measures the vapor pressure inside the boiler 20, and a combustion position (combustion state) of the boiler 20. A local control unit 25.

  The local vapor pressure measurement unit 27 includes a vapor pressure sensor, and measures the vapor pressure inside the boiler 20.

The local control unit 25 changes the combustion position (combustion state) of the boiler 20 according to the required load. Specifically, the local control unit 25 determines the steam pressure inside the boiler 20 based on the number control signal transmitted from the number control device 3 via the signal line 16 or measured by the local steam pressure measurement unit 27. Based on the above, the combustion state of the boiler 20 is controlled.
Further, the local control unit 25 transmits a signal used in the number control device 3 to the number control device 3 via the signal line 16. The signals used in the number control device 3 include the steam pressure inside the boiler 20, the actual combustion state of the boiler 20, and other data.

  The boiler body 21 includes a burner 22 that performs combustion, a blower 23, a combustion air duct (not shown), and a fuel supply unit (not shown). The combustion air duct communicates the blower 23 and the burner 22. The blower 23 supplies air (combustion air) used for combustion of the burner 22 to the burner 22 through the combustion air duct. The fuel supply section supplies the burner 22 with the fuel used in the combustion of the burner 22 in an appropriate amount corresponding to the amount of combustion air supplied by the blower 23.

  The step value combustion control is performed by stepwise changing the amount of air supplied to the burner 22. As a configuration for changing the amount of air supplied to the burner 22 in stages, for example, a configuration in which the opening degree of a damper provided in the combustion air duct is changed in stages, a plurality of combustion air ducts are provided, and opened. The structure which increases / decreases the number of the combustion air duct in a state is mentioned.

  Continuous combustion control is performed by continuously changing the amount of air supplied to the burner 22. As a configuration for continuously changing the amount of air supplied to the burner 22, for example, a configuration for continuously changing the rotation speed of the blades of the blower 23, an opening degree of a proportional control valve provided in the combustion air duct ( The structure which changes a combustion ratio) continuously is mentioned.

  Next, a specific example of the transition of the combustion pattern of the boiler according to the first embodiment of the present invention will be described. FIG. 3 is a diagram illustrating a first example of the transition of the combustion pattern of the boiler according to the first embodiment of the present invention. FIG. 4 is a diagram illustrating a second example of the transition of the combustion pattern of the boiler according to the first embodiment of the present invention. FIG. 5 is a diagram showing a third example of the transition of the combustion pattern of the boiler according to the first embodiment of the present invention.

  A first example of the transition of the combustion pattern of each boiler according to the first embodiment of the present invention will be described. In the first example, when one or more entire stage combustion units (virtual boilers) are included between the changed combustion amount and the before-change combustion amount, the stage combustion unit (virtual combustion unit) including the entire combustion unit (virtual boiler) is included. This is an example in which the combustion amount in the boiler is changed by step value combustion control.

  The total combustion amount of the boiler 20 (whole) is changed from 0% to 20%. In this case, one entire stage combustion unit (virtual boiler) is included between the combustion amount after change (20%) and the combustion amount before change (0%) (first virtual boiler B1). Therefore, from the state where the combustion of the first virtual boiler B1 is stopped, the combustion of the first virtual boiler B1 (whole) is performed by the step value combustion control as shown in FIG. Thereby, the total combustion amount of the boiler 20 (whole) becomes 20%.

  Next, the total combustion amount of the boiler 20 (whole) is changed from 20% to 50% (increased by 30%). In this case, only the entire stage combustion unit (virtual boiler) is included between the combustion amount after change (50%) and the combustion amount before change (20%) (second virtual boiler B2, first boiler). 3 virtual boilers B3). Accordingly, the combustion of the second virtual boiler B2 (overall) and the third virtual boiler B3 (overall) is changed to a step value from the state in which the first virtual boiler B1 (overall) is burning, as shown in FIG. This is done by combustion control. Thereby, the total combustion amount of the boiler 20 (whole) becomes 50%.

  Next, the total combustion amount of the boiler 20 (whole) is changed from 50% to 30% (reduced by 20%). In this case, only one whole stage combustion unit (virtual boiler) is included between the combustion amount after change (50%) and the combustion amount before change (30%) (third virtual boiler B3). Therefore, from the state in which the third virtual boiler B3 (whole) is combusting, as shown in FIG. 3C, the combustion of the third virtual boiler B3 is stopped by the step value combustion control. Thereby, the total combustion amount of the boiler 20 (whole) becomes 30%.

  The 2nd example of transfer of the combustion pattern of each boiler concerning a 1st embodiment of the present invention is explained. In the second example, the change of the combustion amount is performed by continuous combustion control when none of the entire stage combustion unit (virtual boiler) is included between the changed combustion amount and the previous combustion amount. It is an example.

  Similar to the first example, as shown in FIG. 4A, the total combustion amount of the boiler 20 (entire) is 20%.

  Next, the total combustion amount of the boiler 20 (whole) is changed from 20% to 27% (increased by 7%). In this case, the entire staged combustion unit (virtual boiler) is not included between the changed combustion amount (27%) and the changed combustion amount (20%). Therefore, from the state in which the first virtual boiler B1 (whole) is combusting, as shown in FIG. 4B, the second virtual boiler B2 is burned by continuous combustion control. Accordingly, the second virtual boiler B2 is combusted by an amount equivalent to 7%, and the total combustion amount of the boiler 20 (entire) becomes 27%.

  Next, the total combustion amount of the boiler 20 (whole) is changed from 27% to 35% (increased by 8%). In this case, the entire stage combustion unit (virtual boiler) is not included between the changed combustion amount (35%) and the changed combustion amount (27%). Therefore, as shown in FIG. 4C, the second virtual boiler B2 and the third virtual boiler B3 are burned by continuous combustion control from the state where the second virtual boiler B2 is combusted by an amount equivalent to 7%. As a result, the third virtual boiler B3 burns by an amount equivalent to 5%, and the total combustion amount of the boiler 20 (entire) becomes 35%.

  Next, the total combustion amount of the boiler 20 (whole) is changed from 35% to 28% (reduced by 7%). In this case, the entire stage combustion unit (virtual boiler) is not included between the combustion amount after the change (28%) and the combustion amount before the change (35%). Therefore, from the state where the third virtual boiler B3 is combusted by an amount corresponding to 5%, as shown in FIG. 4D, the combustion stop of the third virtual boiler B3 and the change of the combustion amount of the second virtual boiler B2 are performed. Is performed by continuous combustion control. As a result, the second virtual boiler B2 is in a state of being combusted by an amount corresponding to 8%, and the total combustion amount of the boiler 20 (entire) is 28%.

  The 3rd example of transfer of the combustion pattern of each boiler concerning a 1st embodiment of the present invention is explained. In the third example, when one or more entire stage combustion units (virtual boilers) are included between the changed combustion amount and the before-change combustion amount, the stage combustion unit (virtual combustion unit) including the entire combustion unit (virtual boiler) is included. In this example, the combustion amount in the boiler is changed by the step value combustion control, and the combustion amount in the step combustion unit (virtual boiler) not including the whole is changed by the continuous combustion control.

  As in the second example, as shown in FIGS. 4A and 4B, the total combustion amount of the boiler 20 (entire) is 27%.

  Next, the total combustion amount of the boiler 20 (whole) is changed from 27% to 61% (increased by 34%). In this case, the entire stage combustion unit (virtual boiler) is included between the combustion amount after change (61%) and the combustion amount before change (27%) (the third virtual boiler B3) and the whole There are stage combustion units (second virtual boiler B2, fourth virtual boiler B4) that are not included. Therefore, from the state where the second virtual boiler B2 is combusted by an amount equivalent to 7%, as shown in FIG. 5C, the second virtual boiler B2 is burned by continuous combustion control, and the third virtual boiler B3 ( The whole) combustion is performed by the step value combustion control, and the combustion of the fourth virtual boiler B4 is performed by the continuous combustion control. Accordingly, the fourth virtual boiler B4 is combusted by an amount corresponding to 11%, and the total combustion amount of the boiler 20 (entire) becomes 61%.

  Next, the total combustion amount of the boiler 20 (whole) is changed from 61% to 28% (decreased by 33%). In this case, the entire stage combustion unit (virtual boiler) is included between the combustion amount after the change (28%) and the combustion amount before the change (61%) (the third virtual boiler B3) and the whole. There are stage combustion units (second virtual boiler B2, fourth virtual boiler B4) that are not included. Accordingly, from the state in which the fourth virtual boiler B4 is combusted by an amount corresponding to 11%, the combustion of the third virtual boiler B3 is stopped by the step value combustion control as shown in FIG. The combustion amount of the virtual boiler B2 is changed by continuous combustion control. As a result, the second virtual boiler B2 is in a state of being combusted by an amount corresponding to 8%, and the total combustion amount of the boiler 20 (entire) is 28%.

  Next, operation | movement of the boiler system 1 of 1st Embodiment is demonstrated, referring FIG. FIG. 6 is a flowchart showing combustion control of the boiler system according to the first embodiment of the present invention. The operation shown in FIG. 6 is a processing flow after the boiler 20 is instructed to change the combustion amount.

  In step ST1, the control unit 4 determines whether or not one or more whole stage combustion units (virtual boilers) are included between the changed combustion amount and the changed combustion amount. If the entire stage combustion unit (virtual boiler) is included (YES), the process proceeds to step ST2. If none of the entire staged combustion unit (virtual boiler) is included (NO), the process proceeds to step ST4.

  In step ST <b> 2, the control unit 4 determines whether or not the entire “only” of the staged combustion unit (virtual boiler) is included between the changed combustion amount and the changed combustion amount. If the entire stage combustion unit (virtual boiler) “only” is included (YES), the process proceeds to step ST3. If all of the staged combustion units (virtual boilers) are included (NO), the process proceeds to step ST5.

  In step ST3, the control unit 4 causes the boiler 20 to perform stage value combustion control corresponding to the stage combustion unit (virtual boiler) that is entirely included. Thereafter, the process ends.

  In the case of NO in step ST1, in step ST4, the control unit 4 causes the boiler 20 to perform continuous combustion control. Thereafter, the process ends.

  In the case of NO in step ST2, in step ST5, the control unit 4 causes the boiler 20 to perform the stage value combustion control corresponding to the stage combustion unit (virtual boiler) including the whole, and the whole is not included. Continuous combustion control corresponding to the staged combustion unit (virtual boiler) is performed. Thereafter, the process ends.

According to the boiler system 1 of 1st Embodiment demonstrated above, there exist the following effects.
The boiler system 1 according to the first embodiment can perform step value combustion control in which combustion is performed in a plurality of stepwise stage combustion positions and the combustion amount is changed in stages, and the combustion amount is continuously changed. The boiler 20 which can perform combustion control, and the control part 4 which performs step value combustion control and / or continuous combustion control with respect to the boiler 20, and changes a combustion amount are provided. When one or more entire stage combustion units (virtual boilers) are included between the changed combustion amount and the unburned combustion amount, the control unit 4 includes the entire stage combustion unit (virtual boiler) including the entire combustion unit. ) Is changed by the step value combustion control, and the combustion amount in the stage combustion unit (virtual boiler) that is not included is changed by the continuous combustion control. When none of the entire stage combustion unit (virtual boiler) is included in the combustion amount, the combustion amount is changed only by continuous combustion control.

  Therefore, according to the boiler system 1 of the first embodiment, it is possible to provide a boiler system that is excellent in the stability of supply of steam and the ability to follow fluctuations in required load. Specifically, when the required load is relatively stable, it is possible to improve the supply stability of the steam by closely following the fluctuation of the required load by continuous combustion control. On the other hand, when there is a sudden load fluctuation, it is possible to shift to a predetermined combustion state (combustion position) with high followability (responsiveness) by step value combustion control.

  In the boiler system 1 of the first embodiment, the step value combustion control is performed by changing the amount of air supplied to the burner 22 in stages, and the continuous combustion control is performed by changing the amount of air supplied to the burner 22. This is done by changing the amount continuously. Therefore, the step value combustion control and / or the continuous combustion control can be executed with a simple configuration.

Second Embodiment
Next, the boiler system which concerns on 2nd Embodiment is demonstrated, referring drawings. In the description of the second embodiment, the same constituent elements as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  In the second embodiment, the control unit 4 changes the combustion amount by “only” the step value combustion control when the changed combustion amount matches the step combustion position. The control unit 4 also includes a staged combustion unit (virtual boiler) in which the changed combustion amount does not coincide with the staged combustion position and includes the changed combustion amount, and a staged combustion unit (virtual combustion unit) in which the changed combustion amount is included. When the boiler is the same, the combustion amount is changed by “continuous combustion control only”.

  The control unit 4 also includes a staged combustion unit (virtual boiler) in which the changed combustion amount does not coincide with the staged combustion position and includes the changed combustion amount, and a staged combustion unit (virtual combustion unit) in which the changed combustion amount is included. If the boiler is different from the boiler), the combustion quantity in the stage combustion unit (virtual boiler) that does not include the changed combustion quantity is changed by the stage value combustion control, and the stage combustion unit that includes the changed combustion quantity The amount of combustion in the (virtual boiler) is changed by continuous combustion control.

  Next, a specific example of the transition of the combustion pattern of the boiler according to the second embodiment of the present invention will be described. FIG. 7 is a diagram showing a first example of the transition of the combustion pattern of the boiler according to the second embodiment of the present invention. FIG. 8 is a diagram illustrating a second example of the transition of the combustion pattern of the boiler according to the second embodiment of the present invention. FIG. 9 is a diagram showing a third example of the transition of the combustion pattern of the boiler according to the second embodiment of the present invention.

  The 1st example of transfer of the combustion pattern of each boiler concerning a 2nd embodiment of the present invention is explained. In the first example, when the changed combustion amount matches the stage combustion position, the combustion amount is changed only by the stage value combustion control.

  As shown in FIG. 7A, the total combustion amount of the boiler 20 (entire) is 27%. In this case, the entire first virtual boiler B1 is combusted, and the second virtual boiler B2 is combusted by an amount corresponding to 7%.

  Next, the total combustion amount of the boiler 20 (whole) is changed from 27% to 50% (increased by 23%). In this case, the changed combustion amount (50%) coincides with the stage combustion position P3 (50%). Accordingly, the combustion of the second virtual boiler B2 (overall) and the third virtual boiler B3 (overall) is changed to a step value from the state where the total combustion amount of the boiler 20 (overall) is 27%, as shown in FIG. 7B. Only by combustion control. Thereby, the total combustion amount of the boiler 20 (whole) becomes 50%.

  When the entire stage combustion unit (virtual boiler) is burned by stage value combustion control from the state where the stage combustion unit (virtual boiler) is burning but not entirely burned (partial combustion state) Is more excellent in followability (responsiveness) than in the case where the entire staged combustion unit (virtual boiler) is burned by continuous combustion control from a partial combustion state.

  Next, the total combustion amount of the boiler 20 (whole) is changed from 50% to 30% (reduced by 20%). In this case, the changed combustion amount (30%) coincides with the stage combustion position P2 (30%). Therefore, from the state where the total combustion amount of the boiler 20 (overall) is 50%, as shown in FIG. 7C, the combustion of the third virtual boiler B3 (overall) is stopped only by the step value combustion control. Thereby, the total combustion amount of the boiler 20 (whole) becomes 30%.

  The 2nd example of transfer of the combustion pattern of each boiler concerning a 2nd embodiment of the present invention is explained. In the second example, when the changed combustion amount does not coincide with the step combustion position, the change of the combustion amount in the step combustion unit (virtual boiler) not including the changed combustion amount is performed by the step value combustion control. In addition, it is an example in which the change in the combustion amount in the staged combustion unit (virtual boiler) including the changed combustion amount is performed by continuous combustion control, and the step is performed between the changed combustion amount and the changed combustion amount. This is an example in which the entire combustion unit (virtual boiler) is not included.

  The total combustion amount of the boiler 20 (whole) is changed from 0% to 20%. In this case, the changed combustion amount (20%) matches the stage combustion position P1 (20%). Therefore, from the state where the total combustion amount of the boiler 20 (entire) is 0%, as shown in FIG. 8A, the combustion of the second virtual boiler B2 (overall) is performed only by the step value combustion control. Thereby, the total combustion amount of the boiler 20 (whole) becomes 20%.

  Next, the total combustion amount of the boiler 20 (whole) is changed from 20% to 27% (increased by 7%). In this case, the changed combustion amount (27%) does not coincide with the stage combustion position (20%, 30%, etc.). Therefore, from the state in which the first virtual boiler B1 (whole) is combusting, as shown in FIG. 8B, the second virtual boiler B2 is burned by continuous combustion control. Accordingly, the second virtual boiler B2 is combusted by an amount equivalent to 7%, and the total combustion amount of the boiler 20 (entire) becomes 27%.

Next, the total combustion amount of the boiler 20 (whole) is changed from 27% to 35% (increased by 8%). In this case, the changed combustion amount (35%) does not coincide with the stage combustion position (30%, 50%, etc.). Therefore, from the state in which the second virtual boiler B2 is combusted by an amount equivalent to 7%, the combustion of the second virtual boiler B2 that does not include the changed amount of combustion as shown in FIG. While performing by control, combustion of 3rd virtual boiler B3 in which the combustion amount after a change is contained is performed by continuous combustion control. As a result, the third virtual boiler B3 burns by an amount equivalent to 5%, and the total combustion amount of the boiler 20 (entire) becomes 35%.
Note that when the combustion of the second virtual boiler B2 that does not include the changed combustion amount is performed by the step value combustion control, the followability (responsiveness) is excellent as compared with the case where the combustion is performed by the continuous combustion control.

Next, the total combustion amount of the boiler 20 (whole) is changed from 35% to 28% (reduced by 7%). In this case, the changed combustion amount (28%) does not coincide with the stage combustion position (30%, 20%, etc.). Therefore, from the state in which the third virtual boiler B3 is combusted by an amount corresponding to 5%, as shown in FIG. 8D, the combustion of the third virtual boiler B3 that does not include the changed combustion amount is staged. While performing by value combustion control, combustion of 2nd virtual boiler B2 in which the combustion amount after a change is contained is performed by continuous combustion control. As a result, the second virtual boiler B2 is in a state of being combusted by an amount corresponding to 8%, and the total combustion amount of the boiler 20 (entire) is 28%.
In addition, when the stop of combustion of the third virtual boiler B3 that does not include the changed combustion amount is performed by the step value combustion control, the followability (responsiveness) is compared with the case where the stop of the combustion is performed by the continuous combustion control. Excellent.

  The 3rd example of transfer of the combustion pattern of each boiler concerning a 2nd embodiment of the present invention is explained. In the third example, when the subsequent combustion amount does not coincide with the stage combustion position, the combustion amount in the stage combustion unit (virtual boiler) not including the changed combustion amount is changed by the stage value combustion control. In addition, it is an example in which the change in the combustion amount in the staged combustion unit (virtual boiler) including the changed combustion amount is performed by continuous combustion control, and the step is performed between the changed combustion amount and the changed combustion amount. This is an example in which the entire combustion unit (virtual boiler) is included.

  As in the second example, as shown in FIGS. 9A and 9B, the total combustion amount of the boiler 20 (entire) is 27%.

  Next, the total combustion amount of the boiler 20 (whole) is changed from 27% to 61% (increased by 34%). In this case, the changed combustion amount (61%) does not coincide with the stage combustion position (50%, 80%, etc.). Therefore, the second virtual boiler B2 and the third virtual boiler B3 that do not include the changed combustion amount as shown in FIG. 9C from the state where the second virtual boiler B2 is combusted by an amount equivalent to 7%. Is performed by the step value combustion control, and the combustion of the fourth virtual boiler B4 including the changed combustion amount is performed by the continuous combustion control. Accordingly, the fourth virtual boiler B4 is combusted by an amount corresponding to 11%, and the total combustion amount of the boiler 20 (entire) becomes 61%.

  Next, the total combustion amount of the boiler 20 (whole) is changed from 61% to 28% (decreased by 33%). In this case, the changed combustion amount (28%) does not coincide with the stage combustion position (30%, 20%, etc.). Therefore, from the state where the fourth virtual boiler B4 is combusted by an amount corresponding to 11%, as shown in FIG. 9D, the fourth virtual boiler B4 and the third virtual boiler B3 that do not include the changed combustion amount. Is stopped by the step value combustion control, and the combustion of the second virtual boiler B2 including the changed combustion amount is performed by the continuous combustion control. As a result, the second virtual boiler B2 is in a state of being combusted by an amount corresponding to 8%, and the total combustion amount of the boiler 20 (entire) is 28%.

  Next, operation | movement of the boiler system 1 of 2nd Embodiment is demonstrated, referring FIG. FIG. 10 is a flowchart showing combustion control of the boiler system according to the second embodiment of the present invention. The operation shown in FIG. 10 is a processing flow after the boiler 20 is instructed to change the combustion amount.

  In step ST11, the control unit 4 determines whether or not the changed combustion amount matches the stage combustion position. If the changed combustion amount matches the stage combustion position (YES), the process proceeds to step ST12. If the changed combustion amount does not coincide with the stage combustion position (NO), the process proceeds to step ST13.

  In step ST12, the control unit 4 causes the boiler 20 to perform only the step value combustion control to change the combustion amount. Thereafter, the process ends.

  In step ST13, the control unit 4 determines whether or not the stage combustion unit (virtual boiler) including the changed combustion amount is the same as the stage combustion unit (virtual boiler) including the combustion amount before the change. To do. When the stage combustion unit (virtual boiler) including the changed combustion amount is the same as the stage combustion unit (virtual boiler) including the combustion amount before the change (YES), the process proceeds to step ST14. When the stage combustion unit (virtual boiler) including the changed combustion amount is not the same (different) as the stage combustion unit (virtual boiler) including the combustion amount before the change (NO), the process is step ST15. Proceed to

  In step ST14, the control unit 4 causes the boiler 20 to perform only continuous combustion control and changes the combustion amount. Thereafter, the process ends.

  In step ST15, the control unit 4 causes the boiler 20 to change the combustion amount in the stage combustion unit (virtual boiler) that does not include the changed combustion amount by the step value combustion control, and the changed combustion amount is The combustion amount in the included stage combustion unit is changed by continuous combustion control. Thereafter, the process ends.

  According to the boiler system of 2nd Embodiment demonstrated above, there exists an effect similar to 1st Embodiment.

As mentioned above, although preferable embodiment of the boiler system 1 of this invention was described, this invention is not restrict | limited to the above-mentioned embodiment, It can change suitably.
For example, the number of stage combustion positions in the boiler 20 is not limited to six. The amount of combustion at each stage combustion position can be set as appropriate.
The number of boilers 20 constituting the boiler system 1 is not limited to three.

DESCRIPTION OF SYMBOLS 1 Boiler system 2 Boiler group 4 Control part 20 Boiler 22 Burner B1-B5 Stage combustion unit (virtual boiler)

Claims (3)

A boiler capable of performing step value combustion control in which the combustion amount is changed in stages by performing combustion at a plurality of stepwise combustion positions, and continuous combustion control in which the combustion amount is continuously changed; A boiler in which the stage value combustion control and / or the continuous combustion control is performed on the boiler to change the combustion amount, and a range between adjacent stage combustion positions is defined as a stage combustion unit A system,
The controller is
When at least one of the stage combustion units is included between the changed combustion quantity and the before-change combustion quantity, the change of the combustion quantity in the stage combustion unit including the whole is changed to the stage value combustion. And by changing the amount of combustion in the stage combustion unit that is not entirely included by the continuous combustion control,
The boiler system which changes a combustion amount only by the said continuous combustion control, when the whole of the said stage combustion unit is not contained between the combustion amount after a change, and the combustion amount before a change. A boiler capable of performing step value combustion control in which the combustion amount is changed in stages by performing combustion at a plurality of stepwise combustion positions, and continuous combustion control in which the combustion amount is continuously changed; A boiler in which the stage value combustion control and / or the continuous combustion control is performed on the boiler to change the combustion amount, and a range between adjacent stage combustion positions is defined as a stage combustion unit A system,
The controller is
When the changed combustion amount matches the stage combustion position, the combustion amount is changed only by the stage value combustion control, and
When the changed combustion amount does not coincide with the stage combustion position and the stage combustion unit including the changed combustion amount and the stage combustion unit including the pre-change combustion amount are the same, The change is made only by the continuous combustion control, and
When the changed combustion amount does not coincide with the stage combustion position and the stage combustion unit including the changed combustion amount is different from the stage combustion unit including the pre-change combustion amount, A boiler that changes the combustion amount in the stage combustion unit that does not include the combustion amount by the step value combustion control and that changes the combustion amount in the stage combustion unit that includes the changed combustion amount by the continuous combustion control system. The boiler has a burner that performs combustion,
The step value combustion control is performed by stepwise changing the amount of air supplied to the burner, and the continuous combustion control is performed by continuously changing the amount of air supplied to the burner. The boiler system according to claim 1 or 2.

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