JP2014115070A - Boiler system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boiler system which can be operated in the state of satisfactory efficiency in the boiler system allowing boilers having different volumes and efficiency characteristics to be mixed therein.SOLUTION: A boiler system 1 comprises: a boiler group 2 provided with a plurality of boilers 20; and a control part 4 which controls combustion state of the boiler group 2. In the boilers 20, a plurality of operation zones are individually preset corresponding to ranges of predetermined load rate respectively on the plurality of boilers 20, and the control part 4 includes a first increase selection part 451 which selects a boiler located on an operation zone corresponding to the range of the lowest load rate among the plurality of operation zones when the required vaporization amount is larger than an output vaporization amount, a first decrease selection part 461 which selects a boiler located on an operation zone corresponding to the range of the highest load rate among the plurality of operation zones when the required vaporization amount is smaller than the output vaporization amount and an output control part 48 which increases or decreases a vapor amount of the selected boiler by a unit vapor amount part.

Description

  The present invention relates to a boiler system including a boiler group having a plurality of boilers capable of burning by continuously changing a load factor.

2. Description of the Related Art Conventionally, a boiler system has been proposed that includes a boiler group having a plurality of boilers that can be combusted at a plurality of staged combustion positions, and a control unit that controls the combustion state of the boiler group according to a required load. In addition, a so-called proportional control type boiler system has been proposed in which the amount of steam generated is controlled by continuously increasing or decreasing the combustion amount of the boiler.
For example, in Patent Document 1, a boiler is divided into three load zones, a load increase zone, an optimum operation load zone, and a load decrease load zone, and the boiler is burned when burning in the load increase load zone. A control method of a proportional control boiler has been proposed in which the number of boilers is increased and the number of boilers to be burned is reduced when the boiler is burning in a load reduction zone. And in the control method of the proportional control boiler proposed by this patent document 1, after performing increase / decrease in the number of the boilers to burn, all the boilers which are burned are operated by the equal load factor.

Japanese Patent Laid-Open No. 11-132405

  Here, since the method proposed in Patent Document 1 is designed to control boilers by paying attention to the number of boilers to be burned and the combustion load factor, it is appropriate when the capacity and efficiency characteristics of all the boilers are the same. However, when applied to a boiler group in which boilers having different capacities and boilers having different efficiency characteristics are mixed, the control is not appropriate.

Specifically, when a boiler group is configured by a plurality of boilers having different capacities (maximum steam amounts), the following problems occur. As an example, let us consider a case where a boiler group composed of three 2t boilers and two 5t boilers is operated with four combustion units and a required amount of 160%.
If the boiler which is burning by the method proposed in Patent Document 1 is operated at an equal load factor, the combustion instruction to each boiler is 40%. At this time, the output steam amount when the four boilers to be burned are three 2t boilers and one 5t boiler is 4.4t (= 2t × 0.4 × 3 units + 5t × 0.4 × 1 unit) On the other hand, the amount of steam output when two 2t boilers and two 5t boilers are used is 5.6t (= 2t × 0.4 × 2 units + 5t × 0.4 × 2 units). Depending on the selected pattern, the output steam amount corresponding to 160% varies.
In addition, the same 1% combustion instruction for each boiler also varies depending on the capacity, such as 20 kg / h for a 2t boiler and 50 kg / h for a 5t boiler, so the actual output steam amount depends on the boiler that increases or decreases the combustion instruction. The amount of change will be different.
Therefore, when the method proposed in Patent Document 1 is applied to a boiler group in which boilers having different capacities are mixed, control may not be stable.

Moreover, when a boiler group is comprised by the several boiler from which an efficiency characteristic differs, the following problems arise. As an example, consider a boiler group in which the optimum operation (high efficiency) zone is composed of 50 to 70% boilers, 20 to 40% boilers, and 80 to 100% boilers.
In the method proposed in Patent Document 1, in order to operate a burning boiler with a uniform load factor, when applied to such a group of boilers, one boiler can be operated with high efficiency. Other boilers cannot be operated with high efficiency.
Therefore, when the method proposed in Patent Document 1 is applied to a boiler group in which boilers having different efficiency characteristics are mixed, it becomes difficult to operate all the boilers with high efficiency, and an improvement in system efficiency is expected. I can't.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a boiler system that can be operated in an efficient state even in a boiler group in which boilers having different capacities and efficiency characteristics are mixed. And

  The present invention is a boiler system including a boiler group including a plurality of boilers capable of burning by continuously changing a load factor, and a control unit that controls a combustion state of the boiler group according to a required load. The plurality of boilers are set with a unit steam amount, which is a unit of variable steam amount, and each of the plurality of boilers has a plurality of operation zones corresponding to a predetermined load factor range. It is set individually, and the control unit is a required steam amount calculation unit that calculates a required steam amount that is a steam amount required according to the required load, and a steam amount that is output by the boiler group An output steam amount calculation unit that calculates an output steam amount, a deviation calculation unit that calculates a deviation amount between the required steam amount and the output steam amount, and a magnitude that determines the size of the required steam amount and the output steam amount In the determination unit and the size determination unit When it is determined that the required steam amount is larger than the output steam amount, a combustion increase boiler selection unit that selects a boiler that increases the steam amount, and the required steam amount is converted into the output steam amount by the magnitude determination unit. A combustion reduction boiler selection unit that selects a boiler that reduces the amount of steam when it is determined that the deviation amount calculated by the deviation calculation unit is the combustion increase boiler selection unit or the combustion reduction boiler selection. A deviation amount determination unit for determining whether the amount of steam is equal to or greater than the unit steam amount of the boiler selected by the unit, and the combustion increase when the deviation amount determination unit determines that the deviation amount is equal to or greater than the unit steam amount Increase the steam amount of the boiler selected by the boiler selection unit by the unit steam amount, or change the steam amount of the boiler selected by the combustion reduction boiler selection unit by the unit steam amount. The combustion increase boiler selection unit selects a boiler located in the operation zone corresponding to the lowest load factor range among the plurality of operation zones from the plurality of boilers. A combustion increase boiler selection unit that selects, from the plurality of boilers, a boiler located in an operation zone corresponding to a range of the highest load factor among the plurality of operation zones. And a reduction selection unit.

  Further, the combustion increase boiler selection unit, when a plurality of boilers are selected by the first increase selection unit, the load factor in the operation zone from the plurality of boilers selected by the first increase selection unit. The combustion reduction boiler selection unit is further selected by the first reduction selection unit when a plurality of boilers are selected by the first reduction selection unit. It is preferable to further include a second reduction selection unit that selects a boiler having the highest load factor in the operation zone from the plurality of boilers.

  The combustion increase boiler selection unit selects the boiler having the highest priority from the plurality of boilers selected by the second increase selection unit when a plurality of boilers are selected by the second increase selection unit. The combustion reduction boiler selection unit further includes a plurality of boilers selected by the second reduction selection unit when the plurality of boilers are selected by the second reduction selection unit. It is preferable to further include a reduction priority selection unit that selects the boiler with the lowest priority.

  The combustion increase boiler selection unit selects the boiler having the highest priority from the plurality of boilers selected by the first increase selection unit when the plurality of boilers are selected by the first increase selection unit. The combustion reduction boiler selection unit further includes a plurality of boilers selected by the first reduction selection unit when the plurality of boilers are selected by the first reduction selection unit. It is preferable to further include a reduction priority selection unit that selects the boiler with the lowest priority.

  The combustion increase boiler selection unit is configured to increase a steam amount from the plurality of boilers when the magnitude determination unit determines that the required steam amount is larger than the output steam amount after the increase in the steam amount. And an unselected increase boiler selection unit that selects a boiler that has not been selected, wherein the first increase selection unit corresponds to the range of the lowest load factor among the boilers selected by the unselected increase boiler selection unit. The combustion reduction boiler selection unit selects the boiler when the required steam amount is determined to be smaller than the output steam amount after the steam amount is reduced by the size determination unit. An unselected reduction boiler selection unit that selects a boiler that has not been selected as a boiler that reduces the amount of steam from the boilers of the boiler, wherein the first reduction selection unit selects the unselected reduction boiler Of the selected boiler by part, it is preferable to select a boiler located on the operating zone corresponding to a range of the highest load factor.

  Further, it further comprises an order storage unit for storing the order of the boilers selected for the boiler for increasing the steam amount and the order of the boilers selected for the boiler for decreasing the steam amount, and selected by the unselected increase boiler selecting unit. The combustion increase boiler selection unit selects the boiler that increases the steam amount in the order stored in the sequence storage unit, and the boiler selected by the unselected decrease boiler selection unit disappears. In this case, it is preferable that the combustion reduction boiler selection unit selects a boiler that reduces the steam amount in the order stored in the order storage unit.

  Moreover, it is preferable that the plurality of operation zones are set corresponding to a range of a load factor when combustion is performed with a boiler efficiency within a predetermined range.

  Further, the plurality of operation zones include a first eco operation zone in which the boiler efficiency is higher than the first threshold value and a second threshold value in which the boiler efficiency is lower than the first threshold value and the first threshold value. A second eco-operation zone that is a load factor range between and a normal operation zone that is a load factor range in which the boiler efficiency is lower than the second threshold, and the second eco-operation zone is An upper second eco-driving zone located in a range with a higher load factor than the first eco-driving zone; and a lower second eco-driving zone located in a range with a lower load factor than the first eco-driving zone; The normal operation zone is located in a range where the load factor is higher than the upper second eco-operation zone and in a range where the load factor is lower than the lower second eco-operation zone. Lower normal operation zone and It may be provided with.

  Further, the plurality of operation zones include a first eco operation zone in which the boiler efficiency is higher than the first threshold value and a second threshold value in which the boiler efficiency is lower than the first threshold value and the first threshold value. A second eco-operation zone that is a load factor range between and a normal operation zone that is a load factor range in which the boiler efficiency is lower than the second threshold, and the second eco-operation zone is An upper second eco-driving zone located in a range with a higher load factor than the first eco-driving zone; and a lower second eco-driving zone located in a range with a lower load factor than the first eco-driving zone; The normal operation zone may be located in a range with a higher load factor than the upper second eco-operation zone.

  Further, the plurality of operation zones include a first eco operation zone in which the boiler efficiency is higher than the first threshold value and a second threshold value in which the boiler efficiency is lower than the first threshold value and the first threshold value. A second eco-operation zone that is a load factor range between and a normal operation zone that is a load factor range in which the boiler efficiency is lower than the second threshold, and the second eco-operation zone is An upper second eco-driving zone located in a range with a higher load factor than the first eco-driving zone; and a lower second eco-driving zone located in a range with a lower load factor than the first eco-driving zone; The normal operation zone may be located in a range where the load factor is lower than that of the lower second eco-operation zone.

  Further, the plurality of operation zones include a first eco operation zone in which the boiler efficiency is higher than the first threshold value and a second threshold value in which the boiler efficiency is lower than the first threshold value and the first threshold value. A second eco-operation zone that is a load factor range between and a normal operation zone that is a load factor range in which the boiler efficiency is lower than the second threshold, and the second eco-operation zone is The normal operation zone may be located in a range where the load factor is lower than that of the second eco-operation zone while being located in a range where the load factor is lower than that of the first eco-operation zone.

  Further, the plurality of operation zones include a first eco operation zone in which the boiler efficiency is higher than the first threshold value and a second threshold value in which the boiler efficiency is lower than the first threshold value and the first threshold value. A second eco-operation zone that is a load factor range between and a normal operation zone that is a load factor range in which the boiler efficiency is lower than the second threshold, and the second eco-operation zone is The normal operation zone may be located in a range where the load factor is higher than that of the second eco-operation zone while being located in a range where the load factor is higher than that of the first eco-operation zone.

  In addition, the plurality of operation zones are a first eco-operation zone where the boiler efficiency is higher than the first threshold and a load factor range where the boiler efficiency is lower than the first threshold. An operation zone, and the normal operation zone is located in a range where the load factor is higher than that of the first eco-operation zone and in a range where the load factor is lower than that of the first eco-operation zone. And a lower normal operation zone.

  In addition, the plurality of operation zones are a first eco-operation zone where the boiler efficiency is higher than the first threshold and a load factor range where the boiler efficiency is lower than the first threshold. The normal operation zone may be located in a range where the load factor is lower than that of the first eco-operation zone.

  In addition, the plurality of operation zones are a first eco-operation zone where the boiler efficiency is higher than the first threshold and a load factor range where the boiler efficiency is lower than the first threshold. An operation zone, and the normal operation zone may be located in a range where the load factor is higher than that of the first eco-operation zone.

  The unit steam amount is preferably set individually for each of the plurality of boilers.

  According to the present invention, a boiler system in which boilers having different capacities and efficiency characteristics are mixed can be operated in an efficient state.

It is a figure showing the whole boiler system composition concerning one embodiment of the present invention. It is a figure showing the outline of the boiler group concerning a 1st embodiment of the present invention. It is a figure showing the outline of the boiler group concerning a 1st embodiment of the present invention. It is a block diagram which shows the function structure of the number control apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the outline of operation | movement of the boiler system of 1st Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 1st Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 1st Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 1st Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 1st Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 1st Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 1st Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 1st Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 1st Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 1st Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 1st Embodiment. It is a flowchart which shows the flow of a process of the boiler system of 1st Embodiment. It is a flowchart which shows the flow of a process of the boiler system of 1st Embodiment. It is a block diagram which shows the function structure of the number control apparatus which concerns on 2nd Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 2nd Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 2nd Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 2nd Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 2nd Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 2nd Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 2nd Embodiment. It is a figure which shows the outline of operation | movement of the boiler system of 2nd Embodiment. It is a flowchart which shows the flow of a process of the boiler system of 2nd Embodiment. It is a figure which shows an example of the operation zone set to a boiler. It is a figure which shows an example of the operation zone set to a boiler.

Hereinafter, preferred embodiments of the boiler system of the present invention will be described with reference to the drawings.
First, the overall configuration of the boiler system 1 of the present invention will be described with reference to FIG.
The boiler system 1 includes a boiler group 2 including a plurality of (five) boilers 20, a steam header 6 that collects steam generated in the plurality of boilers 20, and steam that measures the pressure inside the steam header 6. A pressure sensor 7 and a number control device 3 having a controller 4 that controls 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. Details of the number control device 3 will be described later.

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, if the required load (steam consumption) increases due to an increase in demand for the steam use facility 18 and the amount of steam supplied to the steam header 6 (output steam amount described later) is insufficient, the steam header 6 The internal vapor pressure will decrease. On the other hand, if the demand load (steam consumption) decreases due to a decrease in the demand for the steam use facility 18 and the amount of steam supplied to the steam header 6 becomes excessive, the steam pressure inside the steam header 6 increases. Become. 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 necessary steam amount that is a steam amount required according to the consumed steam amount (required load) of the steam using facility 18 based on the steam pressure of the steam header 6.

  Here, the several boiler 20 which comprises the boiler system 1 of this embodiment is demonstrated. FIG.2 and FIG.3 is a figure which shows the outline of the boiler group 2 which concerns on this embodiment.

  As shown in FIG. 2, the boiler group 2 of the present embodiment is configured by mixing boilers 20 having different capacities (maximum steam amounts). As an example, in the present embodiment, the No. 1 boiler is a 2t boiler, the No. 2 boiler is a 2.5t boiler, the No. 3 boiler is a 3t boiler, the No. 4 boiler is a 4t boiler, and the No. 5 boiler is a 6t boiler. . In the present embodiment, the capacities of all of the No. 1 boilers to the No. 5 boilers are different. However, the present invention is not limited to this, and one or a plurality of boilers 20 having different capacities may be mixed. The boiler control method described in detail below is suitable not only when the boilers 20 having different capacities are mixed, but also when the capacities of the plurality of boilers 20 are all the same. Applicable.

The boiler 20 is composed of a proportional control boiler capable of burning by changing the load factor continuously.
The proportional control boiler is a boiler in which the combustion amount can be continuously controlled at least in the range from the minimum combustion state S1 in which boiler combustion can be maintained to the maximum combustion state S2 in which the boiler can be safely combusted. . The proportional control boiler adjusts the amount of combustion by, for example, controlling the opening degree (combustion ratio) of a valve that supplies fuel to the burner and a valve that supplies combustion air.

  In addition, the continuous control of the combustion amount means that the calculation or signal in the local control unit 22 described later is a digital method and is handled in stages (for example, the output (combustion amount) of the boiler 20 is in increments of a predetermined unit). Even when the output is controlled).

In this embodiment, the change of the combustion state between the combustion stop state S0 and the minimum combustion state S1 of the boiler 20 is controlled by turning on / off the combustion of the boiler 20 (burner). In the range from the minimum combustion state S1 to the maximum combustion state S2, the combustion amount can be controlled continuously.
More specifically, as shown in FIG. 2, a unit steam amount U, which is a unit of variable steam amount, is set in each of the plurality of boilers 20. Thereby, the boiler 20 can change the amount of steam in units of the unit steam amount U in the range from the minimum combustion state S1 to the maximum combustion state S2.

The unit steam amount U can be appropriately set according to the steam amount (maximum steam amount) in the maximum combustion state S2 of the boiler 20, but from the viewpoint of improving the followability of the output steam amount to the necessary steam amount in the boiler system 1. It is preferably set to 0.1% to 20% of the maximum steam amount of 20, and more preferably set to 1% to 10%.
As an example, in this embodiment, the unit steam volume of the No. 1 boiler is 100 kg / h (5% of the maximum steam volume), the unit steam volume of the No. 2 boiler is 250 kg / h (10% of the maximum steam volume), Unit 3 boiler unit steam volume 150kg / h (5% of maximum steam volume), Unit 4 boiler unit steam volume 200kg / h (5% of maximum steam volume), Unit 5 boiler unit steam volume 120 kg / h (2% of maximum steam).
Note that the output steam amount indicates the steam amount output by the boiler group 2, and this output steam amount is represented by the total value of the steam amounts output from each of the plurality of boilers 20.

Further, in the present embodiment, the plurality of boilers 20 are provided with a plurality of operation zones that are set corresponding to the range of the load factor in the case of combustion at a predetermined range of boiler efficiency, that is, the first eco-operation zone Z1, A second eco operation zone Z2 and a normal operation zone Z3 are set.
The first eco-operation zone Z1 is a load factor range in which the boiler efficiency (the thermal efficiency of the boiler 20) is higher than the first threshold value (for example, 98%), and the most preferable load factor for burning the boiler 20 It is a range.

  The second eco-operation zone Z2 is a load factor range in which the boiler efficiency is between the first threshold value and a second threshold value (for example, 97%) lower than the first threshold value. As shown in FIG. 3, the second eco-driving zone Z2 includes an upper second eco-driving zone Z21 located in a range where the load factor is higher than that of the first eco-driving zone Z1, and a load that is greater than that of the first eco-driving zone Z1. A lower second eco-operation zone Z22 located in a low rate range.

  The normal operation zone Z3 is a load factor range in which the boiler efficiency is lower than the second threshold value. As shown in FIG. 3, the normal operation zone Z3 includes an upper normal operation zone Z31 located in a range where the load factor is higher than that of the upper second eco-operation zone Z21 and a load factor higher than that of the lower second eco-operation zone Z22. And a lower normal operation zone Z32 located in a lower range.

Here, the boiler group 2 of the present embodiment is configured by mixing boilers 20 having different efficiency characteristics. As an example, in the present embodiment, the first eco operation zone Z1 of the No. 1 boiler is set to a range of load factor 40 to 70%, and the first eco operation zone Z1 of the No. 2 boiler is a range of load factor 50 to 80%. The first eco-operating zone Z1 of the No. 3 boiler is set in a range of 30 to 50% load factor, the first eco-operating zone Z1 of the No. 4 boiler is set in a range of 40 to 60% load factor, The first eco-operation zone Z1 of the No. 5 boiler is set to a load factor of 70 to 80%. Similarly for the second eco-operating zone Z2 and the normal operating zone Z3, the second eco-operating zone Z2 and the normal operating zone Z3 are set in different load factor ranges in the first to fifth boilers.
In this embodiment, the efficiency characteristics of all of the No. 1 boiler to the No. 5 boiler are made different. However, the present invention is not limited to this, and one or a plurality of boilers 20 having different efficiency characteristics may be mixed. Further, the boiler control method described in detail below is suitable not only when the boilers 20 having different efficiency characteristics are mixed, but also when the efficiency characteristics of the plurality of boilers 20 are all the same. It can be suitably applied.

Moreover, the priority order is set to each of the plurality of boilers 20. The priority order is used to select the boiler 20 that performs a combustion instruction or a combustion stop instruction. The priority order can be set, for example, using an integer value so that the lower the numerical value, the higher the priority order. As shown in FIG. 3, when priority of "1" to "5" is assigned to each of the No. 1 to No. 5 boilers, the No. 1 boiler has the highest priority, and the No. 5 boiler priority. Is the lowest. In the normal case, this priority order is changed at predetermined time intervals (for example, 24 hour intervals) under the control of the control unit 4 described later.
In the present embodiment, when increasing the load factor, the boilers 20 are selected in descending order of priority, and when decreasing the load factor, the boilers 20 are selected in ascending order of priority. Yes.

The boiler 20 demonstrated above is provided with the boiler main body 21 in which combustion is performed, and the local control part 22 which controls the combustion state of the boiler 20, as shown in FIG.
The local control unit 22 changes the combustion state of the boiler 20 according to the required load. Specifically, the local control unit 22 controls the combustion state of the boiler 20 based on the number control signal transmitted from the number control device 3 via the signal line 16.
Further, the local control unit 22 transmits a signal used in the number control device 3 to the number control device 3 via the signal line 16. Examples of the signal used in the number control device 3 include an actual combustion state of the boiler 20 and other data.

Next, details of the number control device 3 will be described.
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 state of each boiler 20 corresponding to the required combustion amount, 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 storage unit 5 and a control unit 4.

  The storage unit 5 includes information on instructions given to each boiler 20 under the control of the number control device 3 (control unit 4), information such as the combustion state received from each boiler 20, and operation zones of the plurality of boilers 20. The information regarding the setting, the information regarding the setting of the unit steam amount U of the plurality of boilers 20, the information regarding the setting of the priority order of the plurality of boilers 20, the setting information regarding the change (rotation) of the priority order, and the like are stored.

  The control unit 4 gives various instructions to each boiler 20 via the signal line 16 and receives various data from each boiler 20 to control the combustion state and priority order of the five boilers 20. . When each boiler 20 receives a signal for changing the combustion state from the number control device 3, it controls the boiler 20 according to the instruction.

  Here, the details of the control unit 4 will be described with reference to FIG. FIG. 4 is a functional block diagram showing the configuration of the control unit 4. The control unit 4 includes a necessary steam amount calculation unit 41, an output steam amount calculation unit 42, a deviation calculation unit 43, a magnitude determination unit 44, a combustion increase boiler selection unit 45, a combustion decrease boiler selection unit 46, a deviation An amount determination unit 47 and an output control unit 48 are provided.

The required steam amount calculation unit 41 calculates the required steam amount according to the required load based on the steam pressure of the steam header 6.
The output steam amount calculation unit 42 calculates an output steam amount that is a steam amount output by the boiler group 2 based on the combustion state of each boiler 20 transmitted from the local control unit 22.

The deviation calculation unit 43 calculates a deviation amount between the required steam amount and the output steam amount. Moreover, the deviation calculation part 43, when the vapor | steam quantity of the selected boiler 20 is changed by the below-mentioned output control part 48, required steam quantity, the output steam quantity of the boiler group 2 after steam quantity change, and The amount of deviation is calculated.
The size determination unit 44 determines the size of the required steam amount and the output steam amount.

  The combustion increase boiler selection unit 45 includes a first increase selection unit 451, a second increase selection unit 452, and an increase priority selection unit 453, and the required steam amount is output by the magnitude determination unit 44. If it is determined that it is larger than the boiler, the boiler that increases the steam amount (increases the load factor) is selected.

Specifically, the first increase selection unit 451 corresponds to the range of the lowest load factor among the plurality of operation zones from the plurality of boilers 20 when it is determined that the required steam amount is larger than the output steam amount. The boiler 20 located in the operation zone is selected as a boiler that increases the amount of steam. That is, the 1st increase selection part 451 selects the boiler 20 located in the operation zone in the lower side as a boiler which increases an amount of steam. In the present embodiment, the operation zones are, in order from the lower side, the lower normal operation zone Z32, the lower second eco operation zone Z22, the first eco operation zone Z1, the upper second eco operation zone Z21, and the upper normal operation zone Z31. Is set.
Moreover, the 2nd increase selection part 452 is when the several boiler 20 is selected by the 1st increase selection part 451 (when the boilers 20 located in the operation zone corresponding to the range of the lowest load factor exist). The boiler 20 having the lowest load factor in the operation zone is selected as a boiler that increases the amount of steam.
Further, the increase priority selection unit 453 is located in the operation zone corresponding to the range of the lowest load factor when the plurality of boilers 20 are selected by the second increase selection unit 452 and in the operation zone When there are a plurality of boilers 20 having the lowest load factor), the boiler 20 having the highest priority is selected from the plurality of boilers 20 as a boiler for increasing the steam amount. The increase priority selection unit 453 increases the steam amount of the boiler 20 having the highest priority among the plurality of boilers 20 when the plurality of boilers 20 are selected by the first increase selection unit 451. It is good also as selecting as a boiler. That is, when a plurality of boilers 20 are selected by the first increase selection unit 451, the boiler in which the increase priority selection unit 453 increases the amount of steam based on the priority without using the second increase selection unit 452. It is good also as selecting.

  The “load factor in the operation zone” is calculated by (current load factor−lower limit load factor of the operation zone) / {range of the load factor of the operation zone (= upper limit load factor−lower limit load factor)}. Value. In the present invention, the load factor in the same operation zone is used instead of the load factor of the boiler 20 so as to be suitably applicable to the boiler group 2 in which boilers 20 having different efficiency characteristics are mixed. For example, in the No. 1 boiler in which the first eco-operation zone Z1 is set in the range of the load factor 40 to 70% and the No. 2 boiler in which the first eco-operation zone Z1 is set in the range of the load factor 50 to 80% Consider a case in which the No. 1 boiler is operating at a load factor of 55% and the No. 2 boiler is 60%. In this case, the No. 1 boiler with a low load factor has only a 50% margin to maintain the combustion state in the first eco-operation zone Z1 with respect to the increase in the amount of steam, whereas the No. 2 boiler with a high load factor has 66 %, The efficiency of the boiler system 1 as a whole can be increased by increasing the steam volume of the No. 2 boiler having a high load factor. Therefore, each boiler 20 can be efficiently operated not by simply looking at the load factor but by looking at the load factor in the operation zone.

  Returning to FIG. 4, the combustion reduction boiler selection unit 46 includes a first reduction selection unit 461, a second reduction selection unit 462, and a reduction priority order selection unit 463. When it is determined that the amount is smaller than the output steam amount, a boiler that reduces the steam amount (decreases the load factor) is selected.

Specifically, when it is determined that the required steam amount is smaller than the output steam amount, the first reduction selection unit 461 corresponds to the range of the highest load factor from the plurality of boilers 20 among the plurality of operation zones. The boiler 20 located in the operation zone is selected as a boiler that reduces the amount of steam. That is, the 1st reduction selection part 461 selects the boiler 20 located in the driving | operating zone which exists on the upper side as a boiler which reduces a steam amount.
Moreover, the 2nd reduction | decrease selection part 462 is when the several boiler 20 is selected by the 1st reduction | decrease selection part 461 (when there exist multiple boilers 20 located in the operation zone corresponding to the range of the highest load factor). The boiler 20 having the highest load factor in the operation zone is selected as a boiler that reduces the amount of steam.
Further, the reduction priority selection unit 463 is located in the operation zone corresponding to the range of the highest load factor when the plurality of boilers 20 are selected by the second reduction selection unit 462, and in the operation zone In the case where there are a plurality of boilers 20 having the highest load factor), the boiler 20 having the lowest priority is selected from the plurality of boilers 20 as a boiler for reducing the steam amount. Note that the reduction priority selection unit 463 reduces the steam amount of the boiler 20 having the lowest priority among the plurality of boilers 20 when the first reduction selection unit 461 selects the plurality of boilers 20. It is good also as selecting as a boiler. That is, when a plurality of boilers 20 are selected by the first reduction selection unit 461, the reduction priority selection unit 463 reduces the amount of steam based on the priority without using the second reduction selection unit 462. It is good also as selecting.

The deviation amount determination unit 47 determines whether the deviation amount calculated by the deviation calculation unit 43 is equal to or greater than the unit steam amount U of the boiler 20 selected by the combustion increase boiler selection unit 45 or the combustion decrease boiler selection unit 46.
The output control unit 48 determines the steam of the boiler 20 selected by the combustion increase boiler selection unit 45 or the combustion decrease boiler selection unit 46 when the deviation amount determination unit 47 determines that the deviation amount is equal to or greater than the unit steam amount U. Vary the amount. Specifically, when the required steam amount is larger than the output steam amount, the output control unit 48 increases the steam amount of the boiler 20 selected by the combustion increase boiler selecting unit 45 by the unit steam amount U, and is necessary. When the steam amount is smaller than the output steam amount, the steam amount of the boiler 20 selected by the combustion reduction boiler selecting unit 46 is decreased by the unit steam amount U.

  Here, the details of the control of the combustion state of the plurality of boilers 20 by the boiler system 1 will be described. 5-15 is a figure which shows the outline of the operation | movement which concerns on 1st Embodiment of the boiler system 1, respectively.

<Pattern 1>
First, the operation of changing the steam amount of the boiler 20 based on the operation zone, that is, the operation of selecting the boiler 20 that increases or decreases the steam amount by the first increase selection unit 451 or the first decrease selection unit 461 is shown in FIGS. Explanation will be made with reference to FIG.
As shown in FIG. 5, at present (base time), the No. 1 boiler, No. 2 boiler, and No. 3 boiler are operating at a load factor corresponding to the first eco-operation zone Z1, and the No. 4 boiler is on the upper side. The vehicle is operating at a load factor in a range corresponding to the second eco-operation zone Z21, and the No. 5 boiler is operating at a load factor in a range corresponding to the lower second eco-operation zone Z22. At this time, in the state where the output steam amount is 10100 kg / h, when the necessary steam amount increases to 10300 kg / h (see FIG. 6), the necessary steam amount decreases to 9700 kg / h (see FIGS. 7 and 8). )think about.

When the required steam amount increases, the deviation calculating unit 43 calculates a deviation amount (200 kg / h) between the output steam amount and the required steam amount, and the magnitude determining unit 44 determines whether the output steam amount and the required steam amount are large or small. It is determined that the amount of steam needs to be increased.
Then, the 1st increase selection part 451 of the combustion increase boiler selection part 45 is the boiler 20 located in the operation zone (lowermost operation zone) corresponding to the range of the lowest load factor among No. 1 boilers to No. 5 boilers. Is selected as a boiler that increases the amount of steam. In FIG. 5, since the lower second eco-operation zone Z22 of the No. 5 boiler is the lowermost operation zone, the first increase selection unit 451 selects the No. 5 boiler as a boiler that increases the amount of steam.

  Subsequently, when the deviation amount determination unit 47 determines whether the deviation amount is equal to or greater than the unit steam amount U of the No. 5 boiler, referring to FIG. 2, the unit steam amount U of the No. 5 boiler is 120 kg / h. The deviation amount determination unit 47 determines that the deviation amount (200 kg / h) is equal to or greater than the unit steam amount U of the No. 5 boiler. As a result, as shown in FIG. 6, the output control unit 48 increases the steam amount of the No. 5 boiler by the unit steam amount U (increase from 3600 kg / h to 3720 kg / h), and thereby the output steam amount is also 10100 kg. / H to 10220 kg / h.

  When the steam amount of the No. 5 boiler increases, the deviation calculation unit 43 calculates the deviation amount (80 kg / h) based on the output steam amount (10220 kg / h) of the boiler group 2 after the increase in the steam amount, and the magnitude determination unit 44 Determines that it is necessary to increase the amount of steam from the size. Thereafter, the first increase selection unit 451 selects the No. 5 boiler located in the lower second eco-operation zone Z22 as the boiler for increasing the steam amount, but the unit steam amount U (120 kg / h) of the No. 5 boiler is a deviation. Since it is larger than the amount (80 kg / h), the operation when the required steam amount is increased is completed.

  5 and 6, the timing at which the output control unit 48 increases the steam amount of the No. 5 boiler, and the timing at which the deviation amount determination unit 47 determines that the deviation amount is equal to or greater than the unit steam amount U of the No. 5 boiler. However, this is for ease of understanding. Actually, the output control unit 48 determines that the deviation amount determination unit 47 determines that the deviation amount is not equal to or greater than the unit steam amount U of the No. 5 boiler. For each boiler 20, the steam amount of each boiler is increased by the amount of steam counted based on the unit steam amount U (see step ST6 in FIG. 16). Hereinafter, the same applies to other operation examples.

Further, when the required steam amount is reduced, the deviation calculating unit 43 calculates a deviation amount (400 kg / h) between the output steam amount and the required steam amount, and the magnitude determining unit 44 calculates the difference between the output steam amount and the required steam amount. It is determined that the amount of steam needs to be reduced depending on the size.
Then, the 1st reduction selection part 461 of the combustion reduction boiler selection part 46 makes the boiler 20 located in the operation zone (uppermost operation zone) corresponding to the range of the highest load factor among No. 1 boilers to No. 5 boilers. Select a boiler that reduces the amount of steam. In FIG. 5, since the upper second eco-operation zone Z21 of the No. 4 boiler is the uppermost operation zone, the first reduction selection unit 461 selects the No. 4 boiler as the boiler that reduces the steam amount.

  Subsequently, when the deviation amount determination unit 47 determines whether the deviation amount is equal to or greater than the unit steam amount U of the No. 4 boiler, referring to FIG. 2, the unit steam amount U of the No. 4 boiler is 200 kg / h. The deviation amount determination unit 47 determines that the deviation amount (400 kg / h) is equal to or greater than the unit steam amount U of the No. 4 boiler. As a result, as shown in FIG. 7, the output control unit 48 reduces the steam amount of the No. 4 boiler by the unit steam amount U (reduced from 2800 kg / h to 2600 kg / h), whereby the output steam amount is also 10100 kg. / H to 9900 kg / h.

When the steam amount of the No. 4 boiler decreases, the deviation calculation unit 43 calculates the deviation amount (200 kg / h) based on the output steam amount (9900 kg / h) of the boiler group 2 after the reduction of the steam amount, and the magnitude determination unit 44 Determines that it is necessary to reduce the amount of steam from the size. Thereafter, when the first reduction selection unit 461 selects the No. 4 boiler located in the upper second eco-operation zone Z21 as the boiler for reducing the steam amount, the deviation amount determination unit 47 sets the deviation amount (200 kg / h) to No. 4 machine. It is determined that the unit steam amount U (200 kg / h) or more of the boiler. As a result, as shown in FIG. 8, the output control unit 48 decreases the steam amount of the No. 4 boiler by the unit steam amount U (reduced from 2600 kg / h to 2400 kg / h), and the output steam amount also increases from 9900 kg / h. It will be reduced to 9700 kg / h.
As a result, the output steam amount (9900 kg / h) of the boiler group 2 after the reduction of the steam amount coincides with the required steam amount (9900 kg / h) (deviation amount = 0). The operation ends.

  Thus, in the boiler system 1 of this embodiment, it is supposed to select the boiler 20 which changes a vapor | steam quantity based on an operation zone. Since the operation zone can be appropriately set according to the boiler 20, the boiler system 1 allows each boiler 20 to be operated efficiently even in the boiler group 2 in which boilers 20 having different capacities and efficiency characteristics are mixed. Can do.

<Pattern 2>
Subsequently, an operation when there are a plurality of boilers 20 that change the steam amount based on the operation zone, that is, an operation of selecting the boiler 20 that increases or decreases the steam amount by the second increase selection unit 452 or the second decrease selection unit 462. Will be described with reference to FIGS. In the following, description of operations similar to those of the pattern 1 is simplified or omitted.

  As shown in FIG. 9, the No. 1 boiler is currently operating at a load factor in the range corresponding to the first eco-operation zone Z1 (the reference time), and the No. 2 and No. 5 boilers are in the lower second ecology. The operation is performed at a load factor in a range corresponding to the operation zone Z22, and the No. 3 boiler and the No. 4 boiler are operating at a load factor in a range corresponding to the upper second eco-operation zone Z21. At this time, in the state where the output steam amount is 10200 kg / h, when the necessary steam amount increases to 10600 kg / h (see FIGS. 10 and 11), the necessary steam amount decreases to 9800 kg / h (FIG. 12, Consider (see FIG. 13).

  When the required amount of steam increases, the first increase selection unit 451 of the combustion increase boiler selection unit 45 operates in the operating zone corresponding to the lowest load factor range among the No. 1 to No. 5 boilers (the lowest operating zone). Is selected as a boiler that increases the amount of steam. In FIG. 9, since the lower second eco-operation zone Z22 of the No. 2 boiler and the No. 5 boiler is the lowermost operation zone, the first increase selection unit 451 selects two of the No. 2 boiler and the No. 5 boiler. select.

  Since the plurality of boilers 20 (No. 2 boiler and No. 5 boiler) are selected by the first increase selection unit 451, the second increase selection unit 452 of the combustion increase boiler selection unit 45 includes the No. 2 boiler and the No. 5 boiler. The boiler 20 with the lowest load factor in the lower second eco-operation zone Z22 is selected as a boiler that increases the amount of steam. In FIG. 9, the No. 5 boiler is operating in a state where the load factor in the lower second eco-operation zone Z22 is 75%, whereas the No. 2 boiler is in the lower second eco-operation zone Z22. Since the load factor is 50%, the second increase selection unit 452 selects the No. 2 boiler among the No. 2 boiler and the No. 5 boiler as a boiler that increases the amount of steam.

Here, as shown in FIG. 2, the unit steam amount U of the No. 2 boiler is 250 kg / h, which is smaller than the deviation amount (400 kg / h). Therefore, as shown in FIG. 10, the output control unit 48 increases the steam amount of the No. 2 boiler by the unit steam amount U, and increases the output steam amount from 10200 kg / h to 10450 kg / h.
At this time, since the steam amount of the No. 2 boiler has increased from 1000 kg / h to 1250 kg / h, the load factor in the lower second eco-operation zone Z22 of the No. 2 boiler has also increased from 50% to 100%. Note that a load factor of 100% in the lower second eco-operation zone Z22 is synonymous with a load factor of 0% in the first eco-operation zone Z1, but the second boiler is It is assumed that the vehicle is located in the side second eco-operation zone Z22 (hereinafter, similarly, an operation zone that facilitates explanation of the boundary of the operation zone is assumed).

When the steam amount of the No. 2 boiler increases, the deviation calculating unit 43 calculates the deviation amount (150 kg / h) based on the output steam amount (10450 kg / h) of the boiler group 2 after the increase in the steam amount, and the magnitude determining unit 44 Determines that it is necessary to increase the amount of steam from the magnitude of the required steam amount and the output steam amount. Thereafter, the first increase selection unit 451 selects the No. 2 boiler and the No. 5 boiler located in the lower second eco-operation zone Z22.
Since the plurality of boilers 20 are selected by the first increase selection unit 451, the second increase selection unit 452 has the lowest load factor in the lower second eco-operation zone Z22 among the No. 2 boiler and the No. 5 boiler. The boiler 20 is selected as a boiler that increases the amount of steam. Here, in FIG. 10, since the steam amount of the No. 2 boiler is increased, the No. 5 boiler has a lower load factor in the lower second eco-operation zone Z22. Selects the No. 5 boiler as a boiler that increases the amount of steam.

Subsequently, since the deviation amount (150 kg / h) is equal to or greater than the unit steam amount U (120 kg / h) of the No. 5 boiler, as shown in FIG. The steam amount is increased by U, and the output steam amount is increased from 10450 kg / h to 10570 kg / h.
Thereafter, the No. 5 boiler is again selected as the boiler for increasing the steam amount from the deviation amount (30 kg / h) of the required steam amount and the output steam amount of the boiler group 2 after the increase in the steam amount. Since U is larger than the deviation amount, it is determined that the steam should not be increased, and the operation when the required steam amount is increased is terminated.

  When the required steam amount is reduced, the first reduction selection unit 461 of the combustion reduction boiler selection unit 46 operates in the operation zone corresponding to the highest load factor range among the No. 1 boiler to the No. 5 boiler (the uppermost operation zone). ) Is selected as a boiler that reduces the amount of steam. In FIG. 9, since the upper second eco-operation zone Z21 of the No. 3 boiler and the No. 4 boiler is the uppermost operation zone, the first reduction selection unit 461 selects two of the No. 3 boiler and the No. 4 boiler. .

  Since the plurality of boilers 20 (No. 3 boiler and No. 4 boiler) are selected by the first reduction selection unit 461, the second reduction selection unit 462 of the combustion reduction boiler selection unit 46 is the No. 3 boiler and the No. 4 boiler. The boiler 20 with the highest load factor in the upper second eco-operation zone Z21 is selected as the boiler that reduces the steam amount. In FIG. 9, the No. 4 boiler is operating with the load factor in the upper second eco-operation zone Z21 being 50%, whereas the No. 3 boiler is in the upper second eco-operation zone Z21. Since the operation is performed in a state where the load factor is 100%, the second reduction selection unit 462 selects the No. 3 boiler among the No. 3 boiler and the No. 4 boiler as a boiler for reducing the steam amount.

Thereafter, since the unit steam amount U (150 kg / h) of the No. 3 boiler is smaller than the deviation amount (400 kg / h), as shown in FIG. 12, the output control unit 48 determines the steam amount of the No. 3 boiler as a unit. The steam amount is decreased by U, and the output steam amount is decreased from 10200 kg / h to 10050 kg / h.
At this time, since the steam amount of the No. 3 boiler has decreased from 1800 kg / h to 1650 kg / h, the load factor in the upper second eco-operation zone Z21 of the No. 3 boiler has also decreased from 100% to 50%.

When the steam amount of the No. 3 boiler decreases, the deviation calculation unit 43 calculates the deviation amount (250 kg / h) based on the output steam amount (10050 kg / h) of the boiler group 2 after the reduction of the steam amount, and the magnitude determination unit 44 Determines that it is necessary to reduce the amount of steam based on the required amount of steam and the amount of output steam. Then, the 1st reduction | decrease selection part 461 selects the No. 3 boiler and No. 4 boiler located in the upper side 2nd eco-operation zone Z21.
Since the plurality of boilers 20 has been selected by the first reduction selection unit 461, the second reduction selection unit 462 has the highest load factor in the upper second eco-operation zone Z21 among the No. 3 boiler and the No. 4 boiler. 20 is selected as the boiler that reduces the amount of steam. Here, in FIG. 12, as a result of the steam amount of the No. 3 boiler being reduced, the load factor in the upper second eco-operation zone Z21 is the same (50%) in the No. 3 boiler and the No. 4 boiler. . As a result, the second reduction selection unit 462 selects the No. 3 boiler and the No. 4 boiler.

  Since the plurality of boilers 20 (No. 3 boiler and No. 4 boiler) are selected by the second reduction selection unit 462, the reduction priority selection unit 463 of the combustion reduction boiler selection unit 46 is the No. 3 boiler and the No. 4 boiler. The boiler 20 with the lowest priority is selected. In FIG. 12, the priority order of the No. 3 boiler is No. 3, and the priority order of the No. 4 boiler is No. 4. Therefore, the reduction priority selection unit 463 selects the No. 4 boiler as the boiler for reducing the steam amount. To do.

Subsequently, as a result of comparison between the unit steam amount U (200 kg / h) and the deviation amount (250 kg / h) of the No. 4 boiler, as shown in FIG. 13, the output control unit 48 determines the steam amount of the No. 4 boiler. The unit steam amount is decreased by U, and the output steam amount is decreased from 10050 kg / h to 9850 kg / h.
Thereafter, the No. 3 boiler is selected again as the boiler for reducing the steam amount from the deviation amount (50 kg / h) between the required steam amount and the output steam amount of the boiler group 2 after the steam amount is reduced. Since U is larger than the deviation amount, it is determined that the steam should not be reduced, and the operation when the required steam amount is reduced ends.

  Thus, in the boiler system 1 of this embodiment, when the several boiler 20 is selected by the selection based on an operation zone, the boiler 20 which changes the amount of steam based on the load factor in an operation zone is provided. You are going to choose. When boilers 20 having different efficiency characteristics coexist, simply selecting the boiler 20 having a high load factor among the plurality of boilers 20 as the boiler 20 that changes the amount of steam cannot efficiently operate each boiler. . In this regard, in the boiler system 1 of the present embodiment, each boiler 20 can be operated efficiently by looking at the load factor in the operation zone instead of simply looking at the load factor.

  In the pattern 2, the operation using the priority is illustrated when the steam amount is decreased. However, the boiler 20 can be selected using the priority even when the steam amount is increased.

<Pattern 2a>
Subsequently, another pattern of the operation when there are a plurality of boilers 20 that change the steam amount based on the operation zone, that is, the boiler 20 that increases or decreases the steam amount by the increase priority selection unit 453 or the decrease priority selection unit 463. The selecting operation will be described with reference to FIGS. 9, 14, and 15. FIG. In the following, description of operations similar to those of the patterns 1 and 2 is simplified or omitted.

As shown in FIG. 9, when the required steam amount increases, the lower second eco-operation zone Z22 of the No. 2 boiler and the No. 5 boiler is the lowermost operation zone. Select two of the No. 5 boiler and No. 5 boiler.
Since the plurality of boilers 20 (No. 2 boiler and No. 5 boiler) are selected by the first increase selection unit 451, the increase priority selection unit 453 of the combustion increase boiler selection unit 45 is the No. 2 boiler and the No. 5 boiler. The boiler 20 with the highest priority is selected. In FIG. 9, the priority order of the No. 2 boiler is fifth, and the priority order of the No. 5 boiler is No. 2, so the increase priority selection unit 453 selects the No. 5 boiler as the boiler that increases the steam amount. .

Thereafter, since the deviation amount (400 kg / h) is equal to or greater than the unit steam amount U (120 kg / h) of the No. 5 boiler, the output control unit 48 sets the steam amount of the No. 5 boiler as the unit steam as shown in FIG. The amount is increased by the amount U, and the output steam amount is increased from 10200 kg / h to 10320 kg / h.
When the steam amount of the No. 5 boiler increases, the boiler that increases the steam amount is selected again according to the deviation amount calculated based on the output steam amount of the boiler group 2 after the increase in the steam amount. The description is omitted because it is repeated.

Further, as shown in FIG. 9, when the required steam amount is reduced, the upper second eco-operation zone Z21 of the No. 3 boiler and the No. 4 boiler is the uppermost operation zone. Select two of the No. 4 boiler and No. 4 boiler.
Since a plurality of boilers 20 (No. 3 boiler and No. 4 boiler) are selected by the first reduction selection unit 461, the reduction priority order selection unit 463 of the combustion reduction boiler selection unit 46 is, among the No. 3 boiler and the No. 4 boiler, The boiler 20 with the lowest priority is selected. In FIG. 9, the priority order of the No. 3 boiler is No. 3, and the priority order of the No. 4 boiler is No. 4. Therefore, the reduction priority selection unit 463 selects the No. 4 boiler as the boiler that reduces the steam amount. .

Thereafter, since the deviation amount (400 kg / h) is equal to or greater than the unit steam amount U (200 kg / h) of the No. 4 boiler, the output control unit 48 sets the steam amount of the No. 4 boiler as the unit steam as shown in FIG. The amount is reduced by the amount U, and the output steam amount is reduced from 10200 kg / h to 10000 kg / h.
When the steam amount of the No. 4 boiler decreases, the boiler that reduces the steam amount is selected again according to the deviation amount calculated based on the output steam amount of the boiler group 2 after the steam amount decrease. The description is omitted because it is repeated.

  Thus, when the some boiler 20 is selected by selection based on an operation zone, it is good also as selecting the boiler 20 which changes steam quantity based on a priority. Even in such a selection, since the operation zone is appropriately set according to the boiler 20, even in the boiler group 2 in which boilers 20 having different capacities and efficiency characteristics are mixed, each boiler 20 is operated efficiently. Can be made.

  Subsequently, the flow of processing for realizing the operation of the boiler system 1 of the present embodiment will be described with reference to FIGS. 16 and 17. 16 and 17 are flowcharts showing the flow of processing of the boiler system 1.

  First, as a preparation for processing, the unit steam amount U is set (step ST1) and the operation zone is set (step ST2) for each boiler 20 and stored in a predetermined area of the storage unit 5.

  Subsequently, in step ST3, the control unit 4 calculates a necessary steam amount and a deviation amount. That is, the required steam amount calculation unit 41 calculates the required steam amount according to the required load based on the steam pressure of the steam header 6, and the output steam amount calculation unit 42 calculates the output steam amount based on the combustion state of each boiler 20. Once calculated, the deviation calculating unit 43 calculates the deviation amount between the required steam amount and the output steam amount.

  Subsequently, in step ST4, the control unit 4 determines whether or not the steam amount needs to be changed. In the present embodiment, the control unit 4 determines that the variation of the steam amount is not necessary when the deviation amount is zero, and determines that the variation of the steam amount is necessary when the deviation amount is not zero. If the change in the amount of steam is not necessary, the process returns to step ST3. If the change in the amount of steam is required, the process proceeds to step ST5.

In step ST5, the control part 4 performs the fluctuation boiler selection process which selects the boiler 20 which fluctuates the amount of steam. The details of the variable boiler selection process will be described later with reference to FIG.
Subsequently, in step ST <b> 6, the control unit 4 outputs a combustion instruction to each boiler 20 and controls the amount of steam output from each boiler 20. That is, the output control unit 48 varies the steam amount of the boiler 20 selected in step ST5 based on the unit steam amount U.
When the process of step ST6 ends, the control unit 4 returns to the process of step ST3 and repeats the processes of step ST3 to step ST6.

Next, details of the variable boiler selection process in step ST5 will be described with reference to FIG.
First, in step ST51, the control unit 4 determines whether it is necessary to increase the steam amount or decrease the steam amount. This determination is made based on the magnitude of the required steam amount and the output steam amount determined by the size determination unit 44. That is, when the required steam amount is larger, it is determined that the steam amount needs to be increased, and when the output steam amount is larger, it is determined that the steam amount needs to be decreased.

  When it is necessary to increase the amount of steam, in step ST52, the control unit 4 selects a steam amount increase candidate boiler. The selection of the steam increase candidate boiler is as described above, and the combustion increase boiler selection unit 45 is a boiler that is a candidate for increasing the steam amount based on the operation zone, the load factor in the operation zone, and the priority order. 20 is selected.

  Subsequently, in step ST53, the control unit 4 (deviation amount determination unit 47) determines whether the deviation amount is equal to or greater than the unit steam amount U of the boiler 20 selected as the steam amount increase candidate boiler. At this time, if the deviation amount is greater than or equal to the unit steam amount U, the control unit 4 then proceeds to the process of step ST54.

In step ST54, the control unit 4 increases the output steam amount and subtracts the deviation amount. That is, based on the unit steam amount U set in the boiler 20 selected in step ST52, the output steam amount calculating unit 42 and the deviation calculating unit 43 increase the output steam amount and subtract the deviation amount.
When the process of step ST54 ends, the control unit 4 returns to the process of step ST52, and repeats the processes of step ST52 to step ST54 until it is determined in step ST53 that the deviation amount is not equal to or greater than the unit steam amount U. If it is determined in step ST53 that the deviation amount is not equal to or greater than the unit steam amount U, the control unit 4 ends the variable boiler selection process, and proceeds to the process in step ST6 in FIG. That is, in step ST6, the steam amount is changed based on the unit steam amount U by the number of times selected in association with the repeated steps ST52 to ST54 (the same applies to steps ST55 to ST57 described later). In general, since there is a time lag between the time when the steam instruction output from the boiler 20 changes after receiving a combustion instruction, the boiler 20 changes the steam amount without considering this time lag due to the flow of such processing. Can be selected.

  Subsequently, when it is necessary to reduce the steam amount, that is, when it is determined NO in step ST51, in step ST55, the control unit 4 selects a steam amount reduction candidate boiler. The selection of the steam reduction candidate boiler is as described above, and the combustion reduction boiler selection unit 46 is a boiler that is a candidate for reducing the steam quantity based on the operation zone, the load factor in the operation zone, and the priority order. 20 is selected.

  Subsequently, in step ST56, the control unit 4 (deviation amount determination unit 47) determines whether the deviation amount is equal to or greater than the unit steam amount U of the boiler 20 selected as the steam amount increase candidate boiler. At this time, if the deviation amount is greater than or equal to the unit steam amount U, the control unit 4 subsequently proceeds to the process of step ST57. On the other hand, when it is determined that the deviation amount is not equal to or greater than the unit steam amount U, the control unit 4 ends the variation boiler selection process, and proceeds to the process of step ST6 in FIG.

In step ST57, the control unit 4 decreases the output steam amount and subtracts the deviation amount. That is, based on the unit steam amount U set in the boiler 20 selected in step ST52, the output steam amount calculating unit 42 and the deviation calculating unit 43 perform a decrease in the output steam amount and a subtraction of the deviation amount.
When the process of step ST57 ends, the control unit 4 returns to the process of step ST55, and repeats the processes of step ST55 to step ST57 until it is determined in step ST56 that the deviation amount is not equal to or greater than the unit steam amount U.

  According to the boiler system 1 of 1st Embodiment demonstrated above, there exist the following effects.

(1) An operation zone is set for each of the plurality of boilers 20, and the control unit 4 increases the steam amount of the boiler 20 located in the lower operation zone when the required steam amount is larger than the output steam amount. When the required steam amount is smaller than the output steam amount, the boiler 20 located in the upper operation zone is selected as the boiler that reduces the steam amount. Thereby, even if the boiler 20 from which an efficiency characteristic differs is mixed, the amount of steam can be changed in an order from the boiler 20 with bad boiler efficiency, and the efficiency as the boiler system 1 whole can be improved.
In the boiler system 1, the unit steam amount U is set for each of the plurality of boilers 20, and the control unit 4 changes the steam amount of the selected boiler 20 by the unit steam amount U. Thereby, since the fluctuation | variation of the steam quantity of the boiler 20 when required steam quantity fluctuates can be performed for every unit steam quantity U, the load factor of several boilers 20 can be equalized, and the pressure stability of the boiler system 1 Can be improved.

  (2) When a plurality of boilers 20 are selected based on the selection based on the operation zone, the control unit 4 determines the steam amount of the boiler 20 having the lowest load factor in the operation zone among the plurality of selected boilers 20. The boiler 20 having the highest load factor in the operation zone is selected as the boiler for reducing the steam amount. Thereby, even if the boilers 20 having different efficiency characteristics are mixed, in order to select a more suitable boiler 20 as a boiler that varies the amount of steam, each boiler 20 can be operated efficiently, and the boiler system 1 The overall efficiency can be improved.

  (3) When a plurality of boilers 20 are selected by selection based on the load factor in the operation zone, the control unit 4 varies the amount of steam based on the priority order among the plurality of selected boilers 20. It was decided to select a boiler. Thereby, even if it is a case where the several boiler 20 is burning in the same state, since the steam quantity of any boiler 20 is fluctuate | varied, according to the fluctuation | variation of required steam quantity, output steam quantity is appropriately set. Can be changed.

  (4) In addition, the control part 4 selects the boiler which fluctuates a steam quantity based on a priority among the selected several boilers 20 when the several boilers 20 are selected by selection based on an operation zone. It is good to do.

  Next, the boiler system 1 which concerns on 2nd Embodiment of this invention is demonstrated with reference to FIGS. Although the boiler system 1 which concerns on 2nd Embodiment is the same as that of 1st Embodiment by the point which selects the boiler 20 which fluctuates the amount of steam based on the operation zone and the load factor and priority in an operation zone, these are the same. It differs from the boiler system 1 which concerns on 1st Embodiment by the point provided with the mechanism which reduces the possibility that the same boiler 20 will be selected continuously by selection based on.

  Since the overall configuration of the boiler system 1 according to the second embodiment and the outline of the boiler group 2 are the same as those in the first embodiment, description thereof is omitted. On the other hand, since the configuration of the number control device 3 of the boiler system 1 according to the second embodiment is different from that of the first embodiment, the number control device 3 of the second embodiment will be described with reference to FIG. In addition, about the structure similar to 1st Embodiment, a code | symbol is made the same and description is abbreviate | omitted.

  The control unit 4 of the number control device 3 further includes an unselected increase boiler selection unit 454 and an unselected decrease boiler selection unit 464 in addition to the configuration of the first embodiment. In addition, the storage unit 5 of the number control device 3 includes an order storage unit 51.

  The unselected increase boiler selection unit 454 determines whether the required steam amount is greater than the output steam amount after the increase in the steam amount by the combustion determination boiler selection unit 45 among the plurality of boilers 20 when the magnitude determination unit 44 determines that the required steam amount is larger than the output steam amount. A boiler other than the boiler that is selected and whose deviation amount is determined to be greater than or equal to the unit steam amount U by the deviation amount determination unit 47 (hereinafter referred to as “selective increase boiler”) is selected. In the following, boilers other than the selective increase boiler are referred to as “unselected increase boilers”.

  The unselected reduction boiler selection unit 464 determines whether the required steam amount is smaller than the output steam amount after the reduction in the steam amount by the combustion determination boiler selection unit 46 among the plurality of boilers 20 when the magnitude determination unit 44 determines that the required steam amount is smaller than the output steam amount. A boiler other than the boiler that has been selected and whose deviation amount is determined to be greater than or equal to the unit steam amount U by the deviation amount determination unit 47 (hereinafter referred to as “selective reduction boiler”) is selected. In the following, boilers other than the selective reduction boiler are referred to as “unselected reduction boilers”.

The order storage unit 51 stores the order of the plurality of boilers 20 selected as the selective increase boiler and the order of the plurality of boilers 20 selected as the selective decrease boiler.
And the combustion increase boiler selection part 45 is the order memory | storage part 51, when it determines with a required steam amount being larger than the output steam amount after a steam amount increase by the magnitude determination part 44, after an unselected increase boiler is lost. Select the boiler that increases the steam volume in the order stored in
In addition, the combustion reduction boiler selection unit 46 determines that the necessary steam amount is smaller than the output steam amount after the reduction of the steam amount after the magnitude determination unit 44 after the unselected reduction boiler disappears, the order storage unit 51. Select the boiler that reduces the steam volume in the order stored in

Here, the order of processing of the first increase selection unit 451 and the unselected increase boiler selection unit 454 constituting the combustion increase boiler selection unit 45 can be arbitrarily set. That is, after the unselected increase boiler selection unit 454 selects an unselected increase boiler, the first increase selection unit 451 may select the boiler 20 based on the operation zone from these unselected increase boilers. After the first increase selection unit 451 selects the boiler 20 based on the operation zone, the unselected increase boiler selection unit 454 selects the unselected increase boiler from the boilers 20 selected by the first increase selection unit 451. Also good.
According to the configuration in which the process of the unselected increase boiler selection unit 454 is performed before the process of the first increase selection unit 451, only the boiler 20 that operates in the range corresponding to the lowermost operation zone sequentially increases the steam amount. According to the configuration in which the process of the first increase selection unit 451 is performed before the process of the unselected increase boiler selection unit 454, all (five) boilers 20 are selected as boilers to be operated. Will be selected as a boiler that sequentially increases the amount of steam.

For example, the No. 1 boiler to the No. 3 boiler operate at a load factor in a range corresponding to the first eco-operation zone Z1, and the No. 4 boiler and the No. 5 boiler in a range corresponding to the lower second eco-operation zone Z22. Let us consider a case where the No. 4 and No. 5 boilers operating at a load factor in the range corresponding to the lower second eco-operation zone Z22 are already selective increase boilers.
When processing is performed in the order of the unselected increase boiler selection unit 454 and the first increase selection unit 451, the unselected increase boiler selection unit 454 selects the unselected increase boiler from the No. 1 boiler to the No. 5 boiler. Therefore, the No. 1 boiler is selected as the unselected increase boiler from the No. 1 boiler, and as a result, either the No. 1 boiler or the No. 3 boiler is selected as the boiler that increases the amount of steam.
On the other hand, when processing is performed in the order of the first increase selection unit 451 and the unselected increase boiler selection unit 454, the first increase selection unit 451 selects the No. 4 boiler and the No. 5 boiler by selecting the boiler 20 based on the operation zone. select. At this time, since the No. 4 boiler and the No. 5 boiler are selective increase boilers, there is no longer an unselected increase boiler, and the combustion increase boiler selection unit 45 increases the amount of steam in the order stored in the sequence storage unit 51. You will choose a boiler. As a result, either the No. 4 boiler or the No. 5 boiler is selected as a boiler that increases the amount of steam.

  Similarly, the order of processing of the first reduction selection unit 461 and the unselected reduction boiler selection unit 464 can be arbitrarily set for the combustion reduction boiler selection unit 46 as well.

  Then, the detail of control of the combustion state of the several boiler 20 by the boiler system 1 which concerns on 2nd Embodiment is demonstrated. FIGS. 19-25 is a figure which shows the outline of the operation | movement which concerns on 2nd Embodiment of the boiler system 1, respectively. 19 to 25, only the operation for increasing the amount of steam is described, but the operation for decreasing the amount of steam is basically the same, so the description thereof is omitted.

<Pattern 3>
First, the operation when processing is performed in the order of the unselected increase boiler selection unit 454 and the first increase selection unit 451 will be described with reference to FIGS.
As shown in FIG. 19, at present (base time), all of the No. 1 boiler to No. 5 boiler are unselected increase boilers, and the No. 1 boiler, No. 2 boiler and No. 3 boiler are in the first eco-operation zone Z1. It operates with the load factor of the corresponding range, and the No. 4 boiler and the No. 5 boiler operate with the load factor of the range corresponding to the lower second eco-operation zone Z22. At this time, a case where the required steam amount is increased to 7500 kg / h in the state where the output steam amount is 7300 kg / h is considered.

  Since all of the No. 1 boilers to No. 5 boilers are unselected increase boilers, the combustion increase boiler selection unit 45 determines whether the No. 1 boilers to No. 5 boilers are based on the operation zone, the load factor and priority in the operation zones. The boiler 20 that increases the amount of steam is selected from the inside. In FIG. 19, the No. 4 boiler and the No. 5 boiler are operated at a load factor in a range corresponding to the lower second eco-operation zone Z22, and the No. 5 boiler is in the operation zone than the No. 4 boiler. Since the load factor is low, the combustion increase boiler selection unit 45 selects the No. 5 boiler as a boiler that increases the amount of steam.

Since the unit steam amount U of the No. 5 boiler is smaller than the deviation amount, as shown in FIG. 20, the output control unit 48 increases the steam amount of the No. 5 boiler by the unit steam amount U (from 2400 kg / h to 2520 kg / h). The No. 5 boiler is a selective increase boiler.
Further, the control unit 4 stores an order indicating that the No. 5 boiler is first selected in the order storage unit 51 of the storage unit 5.

Subsequently, it is assumed that the required steam volume increases from 7500 kg / h to 7700 kg / h after increasing the steam volume of the No. 5 boiler. In this case, the No. 5 boiler is a selective increase boiler, and the No. 1 to No. 4 boilers are non-selected increase boilers. Therefore, the combustion increase boiler selection unit 45 has the load ratio and priority in the operation zone, the operation zone. Based on the above, the boiler 20 that increases the amount of steam is selected from the No. 1 boiler to the No. 4 boiler.
In FIG. 20, since the No. 4 boiler is operating at a load factor in a range corresponding to the lower second eco-operation zone Z22, the No. 4 boiler is selected as a boiler that increases the amount of steam.

Since the unit steam amount U of the No. 4 boiler is smaller than the deviation amount, as shown in FIG. 21, the output control unit 48 increases the steam amount of the No. 4 boiler by the unit steam amount U (from 1200 kg / h to 1400 kg). / H) to make the No. 4 boiler a selective increase boiler.
In addition, the control unit 4 stores an order indicating that the No. 4 boiler has been selected secondly in the order storage unit 51 of the storage unit 5.

Subsequently, it is assumed that the necessary steam amount increases from 7700 kg / h to 7800 kg / h after increasing the steam amount of the No. 4 boiler. In this case, the No. 4 boiler and the No. 5 boiler are selective increase boilers, and the No. 1 boiler and the No. 3 boiler are unselected increase boilers. Therefore, the combustion increase boiler selection unit 45 has a load in the operation zone and the operation zone. Based on the rate and the priority, the boiler 20 that increases the steam amount is selected from the No. 1 boiler to the No. 3 boiler.
In FIG. 21, both the No. 1 boiler, No. 2 boiler, and No. 3 boiler are operating in the first eco-operation zone Z1, and the load factor in the operation zone is the lowest in the No. 1 boiler and No. 2 boiler, The combustion increase boiler selection unit 45 selects the No. 1 boiler having the highest priority as the boiler that increases the amount of steam.

Since the unit steam amount U of the No. 1 boiler is smaller than the deviation amount, as shown in FIG. 22, the output control unit 48 increases the steam amount of the No. 1 boiler by the unit steam amount U (from 1000 kg / h to 1100 kg). / H) to make the Unit 1 boiler a selective increase boiler.
Further, the control unit 4 stores an order indicating that the No. 1 boiler is selected third in the order storage unit 51 of the storage unit 5.

Thereafter, when the necessary steam amount further increases, the combustion increase boiler selection unit 45 increases the steam amount based on the operation zone, the load factor in the operation zone, and the priority order from the unselected increase boilers. Will be selected. As shown in FIG. 23, in this operation example, the second machine boiler is selected next, and finally the third machine boiler is selected. As a result, when all of the No. 1 boilers to No. 5 boilers become selective increase boilers, the presence or absence of selection is cleared, and all of No. 1 boilers to No. 5 boilers are reset to unselected increase boilers.
When the required steam amount further increases and it is necessary to select a boiler that increases the steam amount, the combustion increase boiler selection unit 45 increases the steam amount in accordance with the order stored in the order storage unit 51. Select a boiler. In this operation example, the No. 5 boiler, the No. 4 boiler, the No. 1 boiler, the No. 2 boiler, and the No. 3 boiler are selected in this order.

  According to the operation of such pattern 3, since it is possible to prevent the steam amount of the same boiler from increasing continuously, it is possible to suppress the load factor fluctuation of each boiler 20 and to improve the stability.

<Pattern 3a>
Subsequently, an operation when processing is performed in the order of the first increase selection unit 451 and the unselected increase boiler selection unit 454 will be described with reference to FIGS. 19 to 21, 24, and 25.

  The flow from FIG. 19 to FIG. 21 is the same as that in Pattern 3, and is selected as a boiler that increases the steam amount in the order of No. 5 boiler and No. 4 boiler as the required steam amount increases. Thereafter, as shown in FIG. 21, it is assumed that the required steam amount has increased from 7700 kg / h to 7800 kg / h. In this case, since the required steam amount has increased, the first increase selection unit 451 determines the steam amount from the No. 1 boiler to the No. 5 boiler based on the operation zone, the load factor and priority in the operation zone. The boiler 20 to be increased is selected.

  In FIG. 21, since the No. 4 boiler and the No. 5 boiler are operating at a load factor in the range corresponding to the lower second eco-operation zone Z22, the first increase selection unit 451 is the No. 4 boiler and the No. 5 boiler. Select. Here, although the No. 4 boiler and the No. 5 boiler are selective increase boilers, the boiler 20 operating at a load factor in the range corresponding to the lower second eco-operation zone Z22 is not limited to the No. 4 boiler and the No. 5 boiler. In addition, there is no boiler 20 that is operating at a load factor in a range corresponding to an operation zone lower than the lower second eco-operation zone Z22. Then, the control part 4 clears the presence or absence of selection, and resets a No. 4 boiler and a No. 5 boiler to an unselected increase boiler.

  Then, the combustion increase boiler selection part 45 selects a No. 5 boiler as a boiler which increases a steam quantity according to the order memorize | stored in the order memory | storage part 51. FIG. Since the unit steam amount U of the No. 5 boiler is smaller than the deviation amount, as shown in FIG. 24, the output control unit 48 increases the steam amount of the No. 5 boiler by the unit steam amount U (from 2520 kg / h to 2620 kg). / H) to make the No. 5 boiler a selective increase boiler.

  Thereafter, when the necessary steam amount further increases, the combustion increase boiler selection unit 45 selects a boiler that increases the steam amount from the unselected increase boilers according to the order stored in the order storage unit 51. . As shown in FIG. 25, in this operation example, the No. 4 boiler is next selected. In addition, if it repeats increasing the steam volume of a No. 4 boiler and a No. 5 boiler, an operation zone will switch from the lower 2nd eco-operation zone Z22 to the 1st eco-operation zone Z1. In FIG. 25, at the timing 100, the operation zone of the No. 4 boiler is switched from the lower second eco-operation zone Z22 to the first eco-operation zone Z1. When the operation zone of the No. 4 boiler is switched, the boiler 20 that operates at the load factor in the range corresponding to the lower second eco-operation zone Z22 becomes only the No. 5 boiler. Will be selected as a boiler to increase the amount of steam.

  According to such an operation of the pattern 3a, the steam amount can be changed in order from the boiler 20 having the poor boiler efficiency, and the efficiency of the boiler system 1 as a whole can be improved.

  Then, the flow of the process for implement | achieving operation | movement of the boiler system 1 of 2nd Embodiment is demonstrated. Note that the boiler system 1 of the second embodiment is the same as the boiler system 1 of the first embodiment except for the variable boiler selection process (step ST5 in FIG. 16), and thus the description thereof is omitted.

First, in step ST501, the control unit 4 determines whether it is necessary to increase the steam amount or decrease the steam amount.
When the steam amount needs to be increased, in step ST502, the control unit 4 selects a steam amount increase candidate boiler from among the unselected increase boilers. The selection of the steam increase candidate boiler is as described above, and the combustion increase boiler selection unit 45 determines the steam amount based on the operation zone, the load factor in the operation zone, the priority order, and the order of selection increase boilers. Is selected as a candidate for increasing the number of boilers.

  Subsequently, in step ST503, the control unit 4 (deviation amount determination unit 47) determines whether the deviation amount is equal to or greater than the unit steam amount U of the boiler 20 selected as the steam amount increase candidate boiler. At this time, when the deviation amount is greater than or equal to the unit steam amount U, the control unit 4 proceeds to the process of step ST504, and when the deviation amount is not greater than or equal to the unit steam amount U, the control unit 4 changes. The boiler selection process ends, and the process proceeds to step ST6 in FIG. In step ST504, the control unit 4 increases the output steam amount and subtracts the deviation amount.

  Subsequently, in step ST505, the control unit 4 sets the boiler 20 selected in step ST502 as a selective increase boiler, and stores the order of the selective increase boiler in the order storage unit 51. Subsequently, in step ST506, the control unit 4 determines whether or not an unselected increase boiler exists. At this time, when an unselected increase boiler exists, the control part 4 returns to the process of step ST502. On the other hand, when there is no unselected increase boiler, the control unit 4 resets the selected increase boiler to the unselected increase boiler, and returns to the process of step ST502.

  Subsequently, when it is necessary to reduce the steam amount, that is, when NO is determined in step ST501, in step ST508, the control unit 4 selects a steam amount reduction candidate boiler from among the unselected reduction boilers. Specifically, the combustion reduction boiler selection unit 46 selects the boiler 20 that is a candidate for reducing the amount of steam based on the operation zone, the load factor in the operation zone, the priority order, and the order of selection reduction boilers. .

Subsequently, in step ST509, the control unit 4 (deviation amount determination unit 47) determines whether the deviation amount is equal to or greater than the unit steam amount U of the boiler 20 selected as the steam amount increase candidate boiler. At this time, if the deviation amount is greater than or equal to the unit steam amount U, the control unit 4 proceeds to the process of step ST510. If the deviation amount is not greater than or equal to the unit steam amount U, the control unit 4 varies. The boiler selection process ends, and the process proceeds to step ST6 in FIG. In step ST510, the control unit 4 decreases the output steam amount and subtracts the deviation amount.
Subsequently, in step ST511, the control unit 4 sets the boiler 20 selected in step ST508 as a selective reduction boiler, and stores the order of the selective reduction boiler in the order storage unit 51. Subsequently, in step ST512, the control unit 4 determines whether or not an unselected reduction boiler exists. At this time, when an unselected decreasing boiler exists, the control part 4 returns to the process of step ST508. On the other hand, when there is no unselected decrease boiler, the control part 4 resets a selection decrease boiler to an unselected decrease boiler, and returns to the process of step ST508.

  According to the boiler system 1 of 2nd Embodiment demonstrated above, there exist the following effects.

  (5) When the output steam amount needs to be changed, the control unit 4 preferentially changes the steam amount from the boiler 20 that is not the selective increase boiler or the selective decrease boiler. Thereby, since it can prevent that the vapor | steam amount of the same boiler fluctuates continuously, the load factor fluctuation | variation of each boiler 20 can be suppressed and stability can be improved.

  (6) When all of the plurality of boilers 20 are selective increase boilers or selective decrease boilers, the control unit 4 varies the amount of steam based on the order of the boilers 20 that have become selective increase boilers or selective decrease boilers. The boiler to be selected was selected. Thereby, the processing burden of the control part 4 can be reduced.

  As mentioned above, although preferable embodiment of the boiler system 1 of this invention was described, this invention is not restrict | limited to embodiment mentioned above, It can change suitably.

  For example, in the above-described embodiment, the first eco-operation zone Z1 and the upper second eco-operation zone Z21 are set as a plurality of operation zones set corresponding to the range of the load factor when burning with a boiler efficiency in a predetermined range. The lower second eco-operation zone Z22, the upper normal operation zone Z31, and the lower normal operation zone Z32 are set, but the setting of the operation zone is not limited to this.

  That is, as shown in FIG. 27, the first eco-operation zone Z1, the upper second eco-operation zone Z21 located in a range where the load factor is higher than the first eco-operation zone Z1, and the first eco-operation zone Z1. A lower second eco-operating zone Z22 located in a low load factor range and a normal operating zone Z3 located in a higher load factor range than the upper second eco-operating zone Z21 are set, and the lower second eco-friendly zone Z22 is set. The lower normal operation zone Z32 located in a range where the load factor is lower than that of the operation zone Z22 may not be set.

  Further, the first eco-driving zone Z1, the upper second eco-driving zone Z21 located in a range where the load factor is higher than the first eco-driving zone Z1, and the range where the load factor is lower than the first eco-driving zone Z1. The lower second eco-operation zone Z22 and the normal operation zone Z3 located in a range where the load factor is lower than the lower second eco-operation zone Z22 are set, and the load factor is higher than that of the upper second eco-operation zone Z21. The upper normal operation zone Z31 located in the higher range may not be set.

  In addition, the first eco-driving zone Z1, the second eco-driving zone Z2 located in a range where the load factor is lower than the first eco-driving zone Z1, and the load factor lower than the second eco-driving zone Z2. The normal operation zone Z3 may be set, and the upper second eco-operation zone Z21 and the upper normal operation zone Z31 located in a range where the load factor is higher than that of the first eco-operation zone Z1 may not be set.

  Also, the first eco-driving zone Z1, the second eco-driving zone Z2 that is located in a range where the load factor is higher than the first eco-driving zone Z1, and the load factor that is higher than the second eco-driving zone Z2. The normal operation zone Z3 may be set, and the lower second eco operation zone Z22 and the lower normal operation zone Z32 located in a range where the load factor is lower than that of the first eco operation zone Z1 may not be set.

  In addition, the boiler 20 is set with three types of operation zones, a first eco-operation zone Z1, a second eco-operation zone Z2, and a normal operation zone Z3. It is good also as four or more types. As an example, as shown in FIG. 28, the first eco-operation zone Z1 and the normal operation zone Z3 may be set in the boiler 20, and the second eco-operation zone Z2 may not be set.

  That is, the first eco-operation zone Z1, the upper normal operation zone Z31 located in a range where the load factor is higher than the first eco-operation zone Z1, and the lower location located in a range where the load factor is lower than the first eco-operation zone Z1. The normal operation zone Z32 may be set, and two types of operation zones may be set in the boiler 20 without setting the second eco-operation zone Z2.

  Further, the first eco-operation zone Z1 and the normal operation zone Z3 located in a range where the load factor is lower than the first eco-operation zone Z1 may be set, and the upper normal operation zone Z31 may not be set.

  Alternatively, the first eco-operation zone Z1 and the normal operation zone Z3 located in a range where the load factor is higher than that of the first eco-operation zone Z1 may be set, and the lower normal operation zone Z32 may not be set.

  The types of operation zones set for the plurality of boilers 20 may be common to the plurality of boilers 20 or may be different for each boiler 20.

  DESCRIPTION OF SYMBOLS 1 ... Boiler system, 2 ... Boiler group, 20 ... Boiler, 3 ... Number control device, 4 ... Control part, 41 ... Necessary steam amount calculation part, 42 ... Output steam amount calculation part, 43 ... Deviation calculation part, 44 ... Large and small Determination unit, 45 ... combustion increase boiler selection unit, 451 ... first increase selection unit, 452 ... second increase selection unit, 453 ... increase priority selection unit, 46 ... combustion decrease boiler selection unit, 461 ... first decrease selection unit 462 ... Second reduction selection unit 463 ... Reduction priority order selection unit 47 ... Deviation amount determination unit 48 ... Output control unit

Claims (16)

A boiler system comprising a boiler group including a plurality of boilers capable of burning by continuously changing a load factor, and a control unit that controls a combustion state of the boiler group according to a required load,
In the plurality of boilers, a unit steam amount which is a unit of variable steam amount is set,
Each of the plurality of boilers is individually set with a plurality of operation zones corresponding to a predetermined load factor range,
The controller is
A required steam amount calculation unit that calculates a required steam amount that is a steam amount required according to the required load; and
An output steam amount calculation unit that calculates an output steam amount that is a steam amount output by the boiler group;
A deviation calculating unit for calculating a deviation amount between the required steam amount and the output steam amount;
A size determination unit that determines the size of the required steam amount and the output steam amount;
A combustion increase boiler selection unit that selects a boiler that increases the steam amount when the required steam amount is determined to be larger than the output steam amount by the size determination unit;
A combustion reduction boiler selection unit that selects a boiler that reduces the amount of steam when the required steam amount is determined to be smaller than the output steam amount by the size determination unit;
A deviation amount determination unit for determining whether the deviation amount calculated by the deviation calculation unit is equal to or greater than a unit steam amount of the boiler selected by the combustion increase boiler selection unit or the combustion decrease boiler selection unit;
When the deviation amount determination unit determines that the deviation amount is equal to or greater than the unit steam amount, the steam amount of the boiler selected by the combustion increase boiler selection unit is increased by the unit steam amount, or the combustion An output control unit that reduces the steam amount of the boiler selected by the reduction boiler selection unit by the unit steam amount, and
The combustion increase boiler selector is
A first increase selection unit that selects a boiler located in an operation zone corresponding to a range of the lowest load factor among the plurality of operation zones from the plurality of boilers;
The combustion reduction boiler selection unit is
A boiler system comprising: a first reduction selection unit that selects a boiler located in an operation zone corresponding to a range of a highest load factor among the plurality of operation zones from the plurality of boilers. The combustion increase boiler selector is
When a plurality of boilers are selected by the first increase selection unit, a second increase for selecting the boiler having the lowest load factor in the operation zone from the plurality of boilers selected by the first increase selection unit A selection unit;
The combustion reduction boiler selection unit is
When a plurality of boilers are selected by the first reduction selection unit, a second reduction for selecting the boiler having the highest load factor in the operation zone from the plurality of boilers selected by the first reduction selection unit The boiler system according to claim 1, further comprising a selection unit. The combustion increase boiler selector is
When a plurality of boilers are selected by the second increase selection unit, further comprising an increase priority selection unit that selects the boiler with the highest priority from the plurality of boilers selected by the second increase selection unit,
The combustion reduction boiler selection unit is
And a reduction priority selection unit that selects a boiler having the lowest priority from a plurality of boilers selected by the second reduction selection unit when a plurality of boilers are selected by the second reduction selection unit. Item 3. The boiler system according to Item 2. The combustion increase boiler selector is
When a plurality of boilers are selected by the first increase selection unit, further comprising an increase priority selection unit that selects the boiler with the highest priority from the plurality of boilers selected by the first increase selection unit,
The combustion reduction boiler selection unit is
And a reduction priority selection unit that selects a boiler having the lowest priority from the plurality of boilers selected by the first reduction selection unit when a plurality of boilers are selected by the first reduction selection unit. Item 4. The boiler system according to Item 1. The combustion increase boiler selector is
When it is determined by the size determination unit that the required steam amount is larger than the output steam amount after the increase in the steam amount, an unselected boiler is not selected as the boiler that increases the steam amount from the plurality of boilers. Further comprising a selection increasing boiler selection unit,
The first increase selection unit selects a boiler located in an operation zone corresponding to a range of the lowest load factor among the boilers selected by the unselected increase boiler selection unit;
The combustion reduction boiler selection unit is
When it is determined by the size determination unit that the required steam amount is smaller than the output steam amount after the steam amount is reduced, an unselected boiler is selected from the plurality of boilers as a boiler that reduces the steam amount. Further comprising a selection reduction boiler selection unit,
The said 1st reduction | decrease selection part selects the boiler located in the driving | running zone corresponding to the range of the highest load factor among the boilers selected by the said non-selection reduction boiler selection part. The described boiler system. An order storage unit for storing the order of the boilers selected for the boiler for increasing the steam amount and the order of the boilers selected for the boiler for decreasing the steam amount;
When there is no boiler selected by the unselected increase boiler selection unit, the combustion increase boiler selection unit selects a boiler that increases the amount of steam in the order stored in the sequence storage unit,
6. The boiler according to claim 5, wherein when there is no boiler selected by the unselected reduction boiler selection unit, the combustion reduction boiler selection unit selects a boiler that reduces the steam amount in the order stored in the order storage unit. Boiler system.   The boiler system according to any one of claims 1 to 6, wherein the plurality of operation zones are set corresponding to a range of a load factor when combustion is performed at a boiler efficiency in a predetermined range. The plurality of operation zones are:
A first eco-operation zone that is a load factor range in which the boiler efficiency is higher than the first threshold;
A second eco-operation zone, which is a load factor range in which the boiler efficiency is between the first threshold and a second threshold lower than the first threshold;
A normal operation zone in which the boiler efficiency is in a load factor range in which the boiler efficiency is lower than the second threshold,
The second eco-driving zone includes an upper second eco-driving zone located in a range where the load factor is higher than the first eco-driving zone, and a lower side located in a range where the load factor is lower than the first eco-driving zone. A second eco-driving zone,
The normal operation zone includes an upper normal operation zone located in a range where the load factor is higher than that of the upper second eco-operation zone, and a lower normal region located in a range where the load factor is lower than that of the lower second eco-operation zone. The boiler system according to claim 7, further comprising an operation zone. The plurality of operation zones are:
A first eco-operation zone that is a load factor range in which the boiler efficiency is higher than the first threshold;
A second eco-operation zone, which is a load factor range in which the boiler efficiency is between the first threshold and a second threshold lower than the first threshold;
A normal operation zone in which the boiler efficiency is in a load factor range in which the boiler efficiency is lower than the second threshold,
The second eco-driving zone includes an upper second eco-driving zone located in a range where the load factor is higher than the first eco-driving zone, and a lower side located in a range where the load factor is lower than the first eco-driving zone. A second eco-driving zone,
The boiler system according to claim 7, wherein the normal operation zone is located in a range having a higher load factor than the upper second eco-operation zone. The plurality of operation zones are:
A first eco-operation zone that is a load factor range in which the boiler efficiency is higher than the first threshold;
A second eco-operation zone, which is a load factor range in which the boiler efficiency is between the first threshold and a second threshold lower than the first threshold;
A normal operation zone in which the boiler efficiency is in a load factor range in which the boiler efficiency is lower than the second threshold,
The second eco-driving zone includes an upper second eco-driving zone located in a range where the load factor is higher than the first eco-driving zone, and a lower side located in a range where the load factor is lower than the first eco-driving zone. A second eco-driving zone,
The boiler system according to claim 7, wherein the normal operation zone is located in a range where the load factor is lower than that of the lower second eco-operation zone. The plurality of operation zones are:
A first eco-operation zone that is a load factor range in which the boiler efficiency is higher than the first threshold;
A second eco-operation zone, which is a load factor range in which the boiler efficiency is between the first threshold and a second threshold lower than the first threshold;
A normal operation zone in which the boiler efficiency is in a load factor range in which the boiler efficiency is lower than the second threshold,
The second eco-operation zone is located in a range where the load factor is lower than that of the first eco-operation zone, and the normal operation zone is located in a range where the load factor is lower than that of the second eco-operation zone. 7. The boiler system according to 7. The plurality of operation zones are:
A first eco-operation zone that is a load factor range in which the boiler efficiency is higher than the first threshold;
A second eco-operation zone, which is a load factor range in which the boiler efficiency is between the first threshold and a second threshold lower than the first threshold;
A normal operation zone in which the boiler efficiency is in a load factor range in which the boiler efficiency is lower than the second threshold,
The second eco-operation zone is located in a range where the load factor is higher than that of the first eco-operation zone, and the normal operation zone is located in a range where the load factor is higher than that of the second eco-operation zone. 7. The boiler system according to 7. The plurality of operation zones are:
A first eco-operation zone that is a load factor range in which the boiler efficiency is higher than the first threshold;
A normal operation zone in which the boiler efficiency is in a load factor range in which the boiler efficiency is lower than the first threshold,
The normal operation zone includes an upper normal operation zone located in a range where the load factor is higher than the first eco operation zone, and a lower normal operation zone located in a range where the load factor is lower than the first eco operation zone. The boiler system according to claim 7. The plurality of operation zones are:
A first eco-operation zone that is a load factor range in which the boiler efficiency is higher than the first threshold;
A normal operation zone in which the boiler efficiency is in a load factor range in which the boiler efficiency is lower than the first threshold,
The boiler system according to claim 7, wherein the normal operation zone is located in a range where the load factor is lower than that of the first eco-operation zone. The plurality of operation zones are:
A first eco-operation zone that is a load factor range in which the boiler efficiency is higher than the first threshold;
A normal operation zone in which the boiler efficiency is in a load factor range in which the boiler efficiency is lower than the first threshold,
The boiler system according to claim 7, wherein the normal operation zone is located in a range having a higher load factor than the first eco-operation zone.   The boiler system according to any one of claims 1 to 15, wherein the unit steam amount is individually set for each of the plurality of boilers.

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