JP2014228185A - Boiler system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set the priority properly for boiler groups configured by a plurality of boilers having different characteristics.SOLUTION: A boiler system 1 includes: a boiler group 2 configured by a plurality of different types of boiler groups; and a control unit 4 for controlling a combustion state of the boiler group 2. The different types of boiler groups include: a boiler group A configured by a plurality of boilers 20 in which a boiler characteristic is similar; a boiler group B configured by the plurality of boilers 20, which are the plurality of boilers 20 in which the boiler characteristic is similar, and in which the similar boiler characteristic is different from that in the boiler group A. The control unit includes: a priority setting unit 41 for setting the priority for controlling a combustion state according to the types of the boiler groups, with respect to the boiler 20; and an output control unit 42 for controlling a steam amount outputted from the boiler group 2 by changing a combustion amount of the boiler 20 according to the priority.

Description

  The present invention relates to a boiler system that sets priority of combustion for a plurality of boilers constituting a boiler group.

  2. Description of the Related Art Conventionally, a boiler system that includes a boiler group composed of a plurality of boilers and a control unit that controls the combustion state of the boiler group in accordance with a required load (required load) and supplies an amount of steam according to the required load. Proposed.

In a boiler system including a plurality of boilers, as described in Patent Document 1, priorities are set for a plurality of boilers, and the combustion state of the boiler group is controlled based on the priorities. Steam according to the load is generated (see paragraph 0023 of Patent Document 1).
More specifically, when increasing the number of boilers to be burned by increasing the required load, starting combustion in order from the boilers with the highest priority, and decreasing the number of boilers to be burned by decreasing the required load The combustion is stopped in order from the boiler with the lowest priority.

JP 2013-072609 A

  By the way, in the conventional boiler system, the boiler group is configured by a plurality of boilers having the same or similar characteristics, but in recent years, a boiler system that configures the boiler group by a plurality of boilers having different characteristics is also known. . In such a boiler system, since the characteristics differ among individual boilers, it is not always preferable to uniformly set a priority order for a plurality of boilers as in the prior art, and further improvement has been demanded.

  This invention is made in view of such a problem, and it aims at providing the boiler system which can set a priority appropriately with respect to the boiler group comprised by the several boiler from which a characteristic differs. .

  The present invention is a boiler system including a boiler group configured by a plurality of different boiler groups and a control unit that controls a combustion state of the boiler group, and the different boiler groups have similar boiler characteristics. A first boiler group configured by a plurality of boilers and a plurality of boilers having similar boiler characteristics, the second boiler group being configured by a plurality of boilers having similar characteristics different from the first boiler group And the control unit sets a priority indicating the order of the boilers that change the combustion rate according to the required load for the boiler according to the type of the boiler group, and An output control unit that controls the amount of steam output from the boiler group by changing the combustion amount of the boiler according to the priority order. That.

  The characteristics of the boilers that divide the boiler group are output characteristics of the boiler, and the first boiler group includes a plurality of boilers that change a combustion rate in the entire boiler group by a first ratio in accordance with a change in combustion amount. And the said 2nd boiler group is good also as being comprised by the some boiler which changes the 2nd rate lower than the said 1st rate in the combustion rate in the whole boiler group with the change of combustion amount.

  At this time, the heterogeneous boiler group is set based on a boiler capacity, the boiler belonging to the first boiler group is a large capacity boiler, and the boiler belonging to the second boiler group is a small capacity boiler. Also good.

  The dissimilar boiler group is set based on a control method for the combustion state of the boiler, and the boilers belonging to the first boiler group are step value control boilers that change the combustion rate stepwise, and the second boiler The boiler belonging to the group may be a proportional control boiler that continuously changes the combustion rate.

  The characteristics of the boilers that divide the boiler group are efficiency characteristics of the boiler, and the first boiler group has a plurality of boilers whose boiler efficiency is higher than a predetermined threshold by burning at a combustion rate within a first range. The second boiler group may be configured by a plurality of boilers whose boiler efficiency is higher than the predetermined threshold by burning at a combustion rate within a second range different from the first range. Good.

  Moreover, it is preferable that the said priority setting part changes the kind of boiler group from which the said priority becomes high according to the level of request | requirement load.

  Specifically, the priority order setting unit sets a predetermined number of boilers belonging to the first boiler group at the top of the priority order when the demand load is high and high load, and when the demand load is low and the load is low, A predetermined number of boilers belonging to the second boiler group may be set higher in the priority order.

  Moreover, the said priority order setting part is good also as changing the said priority of the boiler which belongs to the said boiler group for every boiler group.

  ADVANTAGE OF THE INVENTION According to this invention, a priority can be set appropriately with respect to the boiler group comprised by the several boiler from which a characteristic differs.

It is a figure showing the outline of the boiler system of a 1st embodiment of the present invention. It is a figure which shows the outline of the boiler group of the said embodiment. It is a figure which shows the outline of the boiler group of the said embodiment. It is a functional block diagram which shows the structure of the control part of the said embodiment. It is a figure which shows the setting method of the priority by the priority setting part of the said embodiment. It is a figure which shows the setting method of the priority by the priority setting part of 2nd Embodiment. It is a figure which shows the combustion control method of the boiler by the output control part of 3rd Embodiment.

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

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

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

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

  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, with reference to FIG.2 and FIG.3, the boiler group 2 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.
The boiler group 2 of the present embodiment includes a plurality of boilers 20 having different boiler characteristics, and the boilers 20 having the same or similar characteristics among the plurality of boilers 20 having different boiler characteristics constitute a boiler group. In other words, the boiler group 2 of the present embodiment is composed of two or more boiler groups having different boiler characteristics. In this embodiment, for convenience of explanation, the boiler group 2 is configured by two boiler groups. However, the number of boiler groups constituting the boiler group 2 is not limited to two, and may be two or more. I just need it.

  Here, the boiler characteristics include output characteristics related to the amount of steam output from the boiler 20 and efficiency characteristics related to the combustion efficiency of the boiler 20. FIG. 2 shows a boiler group 2 constituted by boiler groups A and B to which boilers 20 having different output characteristics belong, and FIG. 3 is constituted by boiler groups A and B to which a plurality of boilers 20 having different efficiency characteristics belong. Boiler group 2 is shown.

  Referring to FIG. 2, the output characteristics vary depending on the boiler capacity or the combustion control method of boiler 20. The boiler capacity indicates the maximum amount of steam that can be output by the boiler 20, and the combustion control method indicates proportional control or step value control. Here, the proportional control refers to controlling the combustion amount continuously (for example, every 1%) at least in the range from the minimum combustion state to the maximum combustion state. Further, the step value control refers to controlling the combustion amount in stages by switching a plurality of combustion positions (combustion stop position, low combustion position, middle combustion position, high combustion position, etc.).

  The rate of change of the combustion rate in the entire boiler group 2 varies depending on the boiler capacity. That is, even when the combustion amount of the boiler 20 is changed by 10%, the boiler 20 having a small boiler capacity has a relatively small influence on the entire boiler group 2, and the boiler 20 having a large boiler capacity has an influence on the entire boiler group 2. Is relatively large. Therefore, grouping according to the output characteristics can be performed by defining the boiler group according to the boiler capacity.

  Similarly, the rate of change of the combustion rate in the entire boiler group 2 varies depending on the combustion control method of the boiler 20. As an example, a proportional control boiler capable of changing the combustion rate by 1% is compared with a step value control boiler having a combustion ratio of 20: 45: 100 at a low combustion position, a middle combustion position, and a high combustion position. When the proportional control boiler changes the combustion amount by one unit (1%), the combustion rate in the entire boiler group 2 is changed by 0.002% (1/500). On the other hand, when the stage value control boiler changes the combustion amount by one unit, the combustion rate in the boiler group 2 is changed by 0.04%, 0.05%, and 0.11%. Therefore, the change in the combustion amount in the proportional control boiler has a relatively small influence on the entire boiler group 2, and the change in the combustion amount in the step value control boiler has a relatively large influence on the entire boiler group 2. Therefore, the grouping according to the output characteristics can be performed by defining the boiler group according to the combustion control method of the boiler 20.

  With reference to FIG. 2 (A), when a boiler group is prescribed | regulated according to a boiler capacity | capacitance, grouping is performed according to the magnitude of the maximum steam amount (boiler capacity) which can be output from the boiler 20. FIG. In FIG. 2 (A), grouping is performed based on whether or not the boiler capacity is 4000 kg / h or less. The first and second boilers with a boiler capacity of 6000 kg / h belong to boiler group A, and the boiler capacity is Boiler No. 3 boiler with 4000 kg / h, Boiler No. 4 and No. 5 boilers with a boiler capacity of 2000 kg / h belong to boiler group B.

  With reference to FIG. 2 (B), when a boiler group is prescribed | regulated according to the combustion control method of the boiler 20, grouping is performed according to whether the boiler 20 is a proportional control boiler or a step value control boiler. In FIG. 2 (B), the No. 1 and No. 2 boilers that are step value control boilers belong to the boiler group A, and the No. 3 to No. 5 boilers that are proportional control boilers belong to the boiler group B.

  With reference to FIG. 3, as a grouping based on efficiency characteristics, in the present embodiment, a boiler group is defined according to an eco-operation zone of boiler 20 or a maximum combustion efficiency of boiler 20. The eco-operation zone is a combustion rate range in which the boiler efficiency (the thermal efficiency of the boiler 20) is higher than a predetermined value (for example, 97%), and is the most preferable combustion rate range for burning the boiler 20. is there. The maximum combustion efficiency is a combustion rate at which the boiler efficiency is highest.

With reference to FIG. 3 (A), when a boiler group is prescribed | regulated according to an eco-operation zone, grouping is performed based on the position of an eco-operation zone. As an example, in FIG. 3A, the boilers 20 are grouped according to whether or not the eco-operation zone is in a high combustion region (for example, a combustion rate of 60% or more). That is, the No. 1 and No. 2 boilers whose eco-operation zone is in the high combustion region belong to boiler group A, and the No. 3 to No. 5 boilers whose eco-operation zone is in the middle combustion region belong to boiler group B.
In addition, although illustration is abbreviate | omitted, it is good also as grouping based on the breadth of the range of an eco driving zone instead of the position of an eco driving zone. In other words, the boilers 20 may be grouped according to whether or not the range of the eco-driving zone is larger than a predetermined range.

  With reference to FIG. 3 (B), when defining a boiler group according to the maximum combustion efficiency, grouping is performed according to the magnitude of the maximum combustion efficiency of the boiler 20. In FIG. 3B, grouping is performed based on whether or not the maximum combustion efficiency is 98% or more. The first and second boilers with the maximum combustion efficiency of 98% belong to boiler group A, and the maximum combustion efficiency. However, 96% of No. 3 boilers and 97% of No. 4 and No. 5 boilers belong to boiler group B.

Thus, the priority order is set to the boilers 20 that are grouped according to the boiler characteristics. Here, the priority order indicates the order of the boilers 20 that change the combustion rate in accordance with the required load, and is used to select the boilers 20 that give a combustion instruction or a combustion stop instruction. In the present embodiment, when increasing the amount of steam output from the boiler group 2, the combustion rate is increased in order from the boiler 20 with the highest priority, and when decreasing the amount of steam output from the boiler group 2, the priority is increased. The combustion rate is decreased in order from the lower boiler 20.
The details of the priority setting method for the boiler 20 will be described later.

Returning to FIG. 1, the boiler 20 includes a boiler body 21 in which combustion is performed, and a local control unit 22 that controls the combustion state of the boiler 20.
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.
The number control device 3 calculates the required combustion amount of the boiler group 2 according to the required load based on the vapor pressure signal from the vapor pressure sensor 7 and the combustion state of each boiler 20 corresponding to the required combustion amount, and each boiler. The number control signal for controlling the combustion state based on the priority set to 20 is transmitted to each 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 is configured to control the number of control devices 3 (the control unit 4). The contents of instructions given to the boilers 20, information such as the combustion state received from the boilers 20, and the priorities of the plurality of boilers 20. Setting information, setting information related to priority order change (rotation), 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 (local control unit 22) receives a combustion state change instruction signal from the number control device 3, it controls the boiler 20 according to the instruction.

  A specific configuration of the control unit 4 is shown in FIG. FIG. 4 is a functional block diagram showing the configuration of the control unit 4. As shown in FIG. 4, the control unit 4 includes a priority order setting unit 41 and an output control unit 42.

The priority order setting unit 41 sets priorities for the plurality of boilers 20. At this time, the priority order setting unit 41 sets a priority order for the boiler 20 according to the type of the boiler group to which the boiler 20 belongs.
Here, with reference to FIG. 5, the priority order setting method by the priority order setting unit 41 will be described in detail. FIG. 5 is an explanatory diagram of a priority setting method.

As described above, the plurality of boilers 20 are grouped into boiler groups according to boiler characteristics.
The priority order setting unit 41 sets a priority order for this boiler group. In FIG. 5A, the first priority and the fourth priority are set for the boiler group A, and the second priority, the third and the fifth priority are set for the boiler group B.
Moreover, the priority order setting part 41 sets the order within a group in a boiler group with respect to the several boiler 20 which belongs to the same boiler group. In FIG. 5 (B), as the intra-group rank within the boiler group A, the first rank within the group is set for the No. 1 boiler, and the second rank within the group is set for the No. 2 boiler. Moreover, as the group rank within boiler group B, the first rank within the group is set for the No. 5 boiler, the second rank within the group is set for the No. 3 boiler, and the third rank within the group is set for the No. 4 boiler. ing.

The priority order setting unit 41 sets the boilers 20 based on the priority order set for the boiler group (FIG. 5A) and the group order within the boiler group (FIG. 5B). Set the priority order. That is, as shown in FIG. 5 (A), the boiler group A is set to the first priority, and as shown in FIG. 5 (B), the boiler No. 1 in the boiler group A is ranked first in the group. Since it is set, the priority order setting unit 41 sets the No. 1 boiler as the first priority order among the plurality of boilers 20.
As a result, as shown in FIG. 5 (C), No. 1 boiler belonging to boiler group A in the first priority, No. 5 boiler belonging to boiler group B in the second priority, and Boiler group B in the third priority. The No. 3 boiler, the No. 2 boiler belonging to the boiler group A is set at the fourth priority, and the No. 4 boiler belonging to the boiler group B is set at the fifth priority.

Further, the priority order setting unit 41 changes the in-group order (FIG. 5B) in the boiler group at a predetermined time interval (for example, 24 hour interval) (rotation). With such a change in the group order, the priority order of the plurality of boilers 20 is changed. As an example, when the order within the group in the boiler group A is changed, the priority order of the No. 1 and No. 2 boilers belonging to the boiler group A is switched, and the priority order of the No. 1 boiler is changed to the fourth place, and the No. 2 boiler Is changed to the first priority.
Thereby, the bias of the operation state of the boiler 20 can be leveled.

  Returning to FIG. 4, the output control unit 42 controls the amount of steam output from the boiler group 2 by controlling the combustion amount of the boiler 20 in accordance with the set priority order. In the present embodiment, when the required load increases, the output control unit 42 increases the combustion rate in order from the boiler 20 with the highest priority, increases the amount of steam output from the boiler group 2, and decreases the required load. In this case, the combustion rate is decreased in order from the boiler 20 with the lowest priority, and the amount of steam output from the boiler group 2 is decreased.

The boiler system 1 according to the first embodiment has been described above. Then, the boiler system 1 which concerns on 2nd Embodiment is demonstrated. The boiler system 1 according to the second embodiment basically includes the same configuration as the boiler system 1 according to the first embodiment, but the priority order setting method by the priority order setting unit 41 relates to the first embodiment. Different from boiler system 1.
Specifically, in the setting of the priority order for each group, the boiler system 1 according to the first embodiment is simply performed for each boiler group (see FIG. 5A), according to the second embodiment. The boiler system 1 is different in that the type of the boiler group whose priority is higher is changed according to the required load.

  Hereinafter, the boiler system 1 which concerns on 2nd Embodiment is demonstrated. In addition, description is abbreviate | omitted about the part same as the boiler system 1 which concerns on 1st Embodiment.

  In the boiler system 1, a plurality of boilers 20 are grouped into boiler groups according to boiler characteristics. By grouping according to such boiler characteristics, there exist a boiler group to which the boiler 20 capable of fine adjustment of the combustion amount and a boiler group to which the boiler 20 difficult to finely adjust the combustion amount belong. For example, when grouping by boiler output characteristics, small-capacity boilers and proportional control boilers can finely adjust the combustion amount, while large-capacity boilers and step-value control boilers have relatively fine adjustments to the combustion amount. It is difficult to.

  In the boiler system 1 of the second embodiment, paying attention to the characteristics of such a boiler group, the boiler group capable of fine adjustment of the combustion amount is used for load adjustment, and the combustion amount is smaller than that of the boiler group for load adjustment. The priority order for each group is set for a boiler group that is relatively difficult to adjust.

FIG. 6 is an explanatory diagram of a priority setting method by the priority setting unit 41 of the boiler system 1 according to the second embodiment.
With reference to FIG. 6 (A), the priority order setting unit 41 assigns priority to a load adjustment boiler group that can finely adjust the combustion amount for low loads where the required load of the steam-using facility 18 is low. Set higher. On the other hand, with reference to FIG. 6 (B), the priority order setting unit 41 gives priority to the boiler group for the base, which is relatively difficult to finely adjust the combustion amount when the required load of the steam-using facility 18 is high. Set to higher rank. In other words, the priority order setting unit 41 is configured so that the number of higher priority orders occupied by the boiler group for bases differs according to the required load of the steam-using facility 18 (the base use is less in the higher priority order when the load is low, and the higher When loading, there are many bases in the higher priority order), and the priority order for each group is set.

  When grouping by output characteristics, the boiler group to which the small capacity boiler and proportional control boiler belong corresponds to the load adjustment boiler group, and the boiler group to which the large capacity boiler and step value control boiler belong Corresponds to the boiler group. Further, when grouping by efficiency characteristics, as an example, the boiler group to which the boiler 20 with a wide eco-operation zone range belongs corresponds to the boiler group for load adjustment, and the boiler 20 with a narrow eco-operation zone range belongs. The boiler group corresponds to the base boiler group.

  Then, the boiler system 1 which concerns on 3rd Embodiment is demonstrated. The boiler system 1 according to the third embodiment sets the priority order for the load adjustment and base boiler groups according to the required load as in the boiler system 1 according to the second embodiment. Different combustion control is performed for the adjustment and the base.

  Hereinafter, the boiler system 1 which concerns on 3rd Embodiment is demonstrated. In addition, description is abbreviate | omitted about the part same as the boiler system 1 which concerns on 1st Embodiment and 2nd Embodiment.

  FIG. 7 is an explanatory diagram for the combustion control of the boiler 20 by the output control unit 42 of the boiler system 1 according to the third embodiment.

  With reference to FIG. 7 (A), the boilers 20 having the first to fourth priorities are burning, and the boiler 20 having the fifth priority has stopped burning. At this time, among the boilers 20 in the combustion state, the boiler 20 with the first priority belongs to the boiler group A for the base, and the boilers 20 with the second to fourth priority belong to the boiler group B for load adjustment. Yes.

Thereafter, when the required load of the steam using facility 18 fluctuates, the output control unit 42 controls the combustion amount of the boiler 20 according to the priority order to generate steam corresponding to the required load from the boiler group 2.
At this time, the output control unit 42 of the third embodiment controls the combustion of the boilers 20 belonging to the base boiler group and the boilers 20 belonging to the load adjustment boiler group in different modes. As combustion control of a different aspect, it can adjust arbitrarily according to the condition of the boiler system 1. FIG. In this regard, in FIG. 7B, for easy understanding, the output control unit 42 fixes the boilers 20 belonging to the load adjustment boiler group while fixing the combustion amount of the boilers 20 belonging to the base boiler group. By adjusting the amount of combustion, the combustion is controlled in a different manner.

As described above, in the boiler system 1 of the third embodiment, the priority order is set for the load adjustment and base boiler groups according to the required load in the same manner as the boiler system 1 of the second embodiment, and the load Different combustion control is used for the adjustment and base boiler groups. As a result, the required load in the steady state of the steam using equipment 18 is handled by the boiler 20 belonging to the boiler group for the base, and the fluctuation of the required load from the steady state is handled by the boiler 20 belonging to the boiler group for load adjustment. Therefore, the followability to the required load can be improved.
When combustion is performed with the combustion amount of the boiler 20 belonging to the base boiler group fixed, the output control unit 42 fixes the combustion rate at which the boiler 20 belonging to the base boiler group burns most efficiently. It is preferable to make it burn.

  According to the boiler system 1 of this embodiment demonstrated above, there exist the following effects.

  (1) In the boiler system 1 of the present embodiment, a plurality of boilers 20 are grouped according to boiler characteristics, and the priority order setting unit 41 prioritizes the boilers 20 according to the type of the group. Set. Thereby, it can prevent setting a priority order with respect to the several boiler 20 uniformly. That is, it is possible to prevent the higher priority order from being set for the boiler 20 which is not preferable to the higher priority order from the boiler characteristics. As a result, it is possible to appropriately set the priority order for the boiler group 2 constituted by a plurality of boilers 20 having different characteristics.

(2) In addition, it is good also as using the output characteristic of the boiler 20 as a boiler characteristic used for grouping, and when using an output characteristic, the ratio which changes the combustion rate in the boiler group 2 whole with the change of combustion amount Group by.
(3) At this time, grouping may be performed based on the capacity of the boiler 20, and (4) grouping may be performed based on the combustion control method of the boiler 20.
Thereby, a boiler group can be divided into the boiler group for bases, and the boiler group for load adjustment, adjustment of the combustion amount in the boiler group 2 whole becomes easy, and pressure stability can be improved.

(5) Further, as the boiler characteristics used for grouping, the efficiency characteristics of the boiler 20 may be used. When the efficiency characteristics are used, grouping is performed based on the range of the eco-operation zone, the maximum combustion efficiency, and the like. .
Thereby, the boiler 20 can be burned efficiently for every boiler group, and the combustion efficiency in the boiler group 2 whole can be improved.

(6) The priority order for each group may be set according to the level of the required load. (7) Specifically, a boiler group that greatly changes the combustion rate in the entire boiler group 2 with a change in the combustion amount at a high load is set at a higher priority, and a boiler group with a change in the combustion amount at a low load The boiler group which does not change the combustion rate in 2 overall is set to the higher priority.
Accordingly, the number of boilers 20 belonging to the base boiler group can be adjusted according to the level of the required load. The boiler 20 belonging to the base boiler group is burned at a fixed combustion rate, while the combustion amount of the boiler 20 belonging to the load adjusting boiler group is adjusted in accordance with fluctuations in the required load, whereby the boiler Variations in the combustion rate in the entire group 2 can be suppressed, and as a result, followability to the required load can be improved.

  (8) Further, the rank within the group is changed at a predetermined time interval (for example, 24 hour interval). Thereby, the bias of the operation state of the boiler 20 can be leveled. Even in this case, since the priority order is set according to the type of the boiler group, the control state of the entire boiler group 2 is not changed before and after the rotation, and the boiler system 1 is stably operated. Can do.

The preferred embodiment of the boiler system 1 of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and can be modified as appropriate.
For example, in the above-described embodiment, the boiler group 2 is divided into two boiler groups A and B. However, the boiler group 2 may be divided into an arbitrary number of three or more boiler groups.

  For example, in the said embodiment, although this invention was applied to the boiler system provided with the boiler group 2 which consists of the five boilers 20, it is not restricted to this. That is, the present invention may be applied to a boiler system including a boiler group including six or more boilers, or may be applied to a boiler system including a boiler group including two boilers.

DESCRIPTION OF SYMBOLS 1 Boiler system 2 Boiler group 20 Boiler 3 Number control device 4 Control part 41 Priority order setting part 42 Output control part

Claims (8)

A boiler system comprising a boiler group composed of a plurality of different boiler groups, and a control unit that controls a combustion state of the boiler group,
The heterogeneous boiler group is
A first boiler group composed of a plurality of boilers having similar boiler characteristics;
A plurality of boilers having similar boiler characteristics, the second boiler group including a plurality of boilers having similar characteristics different from the first boiler group,
The controller is
A priority order setting unit that sets a priority order indicating the order of boilers that change the combustion rate according to the required load for the boiler according to the type of the boiler group;
An output control unit that controls the amount of steam output from the boiler group by changing the combustion amount of the boiler according to the priority order;
Boiler system equipped with. The boiler characteristics that divide the boiler group are the output characteristics of the boiler,
The first boiler group is composed of a plurality of boilers that change the combustion rate in the entire boiler group by a first ratio in accordance with a change in combustion amount,
2. The boiler system according to claim 1, wherein the second boiler group includes a plurality of boilers that change a combustion rate in the entire boiler group by a second rate lower than the first rate in accordance with a change in a combustion amount. The heterogeneous boiler group is set based on boiler capacity,
The boilers belonging to the first boiler group are large-capacity boilers,
The boilers belonging to the second boiler group are small capacity boilers,
The boiler system according to claim 2. The heterogeneous boiler group is set based on a control method of the combustion state of the boiler,
The boilers belonging to the first boiler group are stage value control boilers that change the combustion rate in stages.
The boilers belonging to the second boiler group are proportional control boilers that continuously change the combustion rate.
The boiler system according to claim 2. The characteristics of the boilers that divide the boiler group are the efficiency characteristics of the boilers,
The first boiler group includes a plurality of boilers whose boiler efficiency is higher than a predetermined threshold by burning at a combustion rate within a first range,
The said 2nd boiler group is comprised by the several boiler from which a boiler efficiency becomes higher than the said predetermined threshold value by burning with the combustion rate in the 2nd range different from the said 1st range. Boiler system.   The boiler system according to any one of claims 1 to 5, wherein the priority order setting unit changes a type of a boiler group having a higher priority according to a level of a required load. The priority order setting unit includes:
When the required load is high and the load is high, a predetermined number of boilers belonging to the first boiler group are set higher in the priority order,
When the required load is low and the load is low, a predetermined number of boilers belonging to the second boiler group are set higher in the priority order.
The boiler system according to claim 6. The boiler system according to any one of claims 1 to 7, wherein the priority order setting unit changes the priority order of boilers belonging to the boiler group for each boiler group.

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