JP6102357B2 - Boiler system - Google Patents

Description

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

  2. Description of the Related Art Conventionally, a boiler system including a boiler group having a plurality of boilers and a control unit that controls the combustion state of the boiler group in accordance with load fluctuations is known. In such a boiler system, the combustion state (load factor) of a plurality of boilers is changed in response to load fluctuations, so that it is possible to operate with high efficiency with little change in the load factor of each boiler. Compared with the case where one is installed, the efficiency of the entire system is improved.

  In such a boiler system, combustion of a boiler that is in a stopped state may start in response to an increase in load, but since a boiler in a stopped state is cooled and rapid steaming is difficult, There has been known a technique for causing a boiler in the state to stand by in a state where steaming is possible (a steaming preparation state) in advance (for example, Patent Document 1).

JP 2002-81604 A

  By the way, in patent document 1, although it is supposed that the number of boilers of a steam supply preparation state will be changed according to load fluctuation | variation, since the usage-amount of the vapor | steam generate | occur | produced from the boiler group usually falls in the predetermined range for every installation. There was room for further ingenuity. That is, if the boiler in the steaming preparation state is increased in response to the temporary load increase exceeding the predetermined range, it will be in the steaming preparation state even to an unnecessary boiler, and the temporary load exceeding the predetermined range. If the boiler in the steaming preparation state is reduced in accordance with the decrease, the originally required boiler cannot be brought into the steaming preparation state and cannot cope with future load fluctuations.

  This invention is made | formed in view of such a problem, and it aims at providing the boiler system which controls appropriately the number of the boilers made into a steaming preparation state.

In the following, the steaming preparation state includes the following states (1) to (3).
(1) Continuous pilot combustion state: In a gas-fired boiler that uses gas as fuel and has a pilot burner and a main burner, the pilot burner is burned to prevent unburned gas from staying inside the boiler 20. When the combustion instruction is received, the main burner can be ignited promptly. The continuous pilot combustion state refers to a state where the pilot burner is burned at least when the combustion of the main burner is stopped. That is, the continuous pilot combustion state includes a case where the combustion of the pilot burner is stopped when the main burner is burning. (2) Light breeze purge state: In an oil-fired boiler that uses oil as fuel, the air blower is continuously driven to maintain the supply of air to the inside of the boiler 20 (can body), thereby vaporizing inside the boiler 20 This is a state in which the burner can be ignited promptly when a combustion instruction is received. The light air purge state includes a case where the blower is operated in a weaker state than when the burner is burned, and a case where the blower is operated in the same state as when the burner is burned. (3) Pressure maintaining state: Steaming is not performed, but the pressure inside the boiler 20 is maintained, and when a combustion instruction is received, steaming can be started promptly.
Moreover, the steam supply preparation state is not only the above (1) to (3) states, but also the states (1) and (3) (the state in which the continuous pilot combustion is performed while maintaining the pressure), and It includes the states (2) and (3) (the state in which the light wind purge is performed while the pressure is maintained).

  The present invention is a boiler system including a boiler group including a plurality of boilers that can burn by changing a load factor, and a control unit that controls a combustion state of the boiler group. A steam amount is set, and the control unit sets a predetermined number of boilers satisfying the standby steam amount as a standby control boiler among the plurality of boilers regardless of whether or not the combustion is performed. The standby control boiler setting unit to be set, the boiler control unit for burning the boiler according to the required load, and the boiler set as the standby control boiler among the non-burning boilers are shifted to the steaming preparation state, The present invention relates to a boiler system including a standby control unit that maintains boilers other than the standby control boiler in a combustion stopped state.

  In addition, priority is set for the plurality of boilers, and the standby control boiler setting unit sets a predetermined number of boilers as the standby control boilers in order from the boiler with the highest priority, and the boiler control unit Are preferably burned in order from the boiler with the highest priority.

  Moreover, it is preferable that at least one boiler among the plurality of boilers is a different capacity boiler having a capacity different from that of the other boilers.

  According to the present invention, since only the boiler for the standby steam amount is set in the steaming preparation state, the number of boilers to be in the steaming preparation state can be appropriately controlled.

It is a figure showing the outline of the boiler system concerning one embodiment of the present invention. It is a figure showing the outline of the boiler group concerning one embodiment of the present invention. It is a functional block diagram which shows the structure of a control part. It is a figure which shows an example of operation | movement of a boiler system.

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 includes a plurality of boilers 20 and generates steam to be supplied to the steam use facility 18 as load equipment.
Each of the plurality of boilers 20 is electrically connected to the number control device 3 through the signal line 16. 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.

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 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 number control device 3 includes a control unit 4 and a storage unit 5.

  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 determine the combustion states of the five boilers 20 and the priority order described later. Control. When the local control unit 22 of each boiler 20 receives the signal for changing the combustion state from the number control device 3, it controls the boiler 20 according to the instruction.

  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 combustion patterns of a plurality of boilers 20. Information on setting conditions, information on setting priorities of a plurality of boilers 20, information on settings on changing priority (rotation), and the like.

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 used 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 usage 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 steam amount (output steam amount described later) supplied to the steam header 6 is insufficient, the steam header 6 The internal vapor pressure will decrease. On the other hand, if the required load (steam consumption) decreases due to a decrease in 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 steam usage amount (required load) of the steam use 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 is a diagram showing an outline of the boiler group 2 according to the present embodiment.
The boiler 20 of this embodiment consists of a proportional control boiler which can be burned 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 (for example, the combustion state at 20% of the maximum combustion amount) to the maximum combustion state S2. It is. 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.

  Further, the continuous control of the combustion amount means that the calculation or signal in the local control unit 22 is digital and handled in stages (for example, the output (combustion amount) of the boiler 20 is controlled in increments of 1%). Even if the output can be controlled virtually continuously.

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, a unit steam amount U, which is a unit of variable steam amount, is set for each of the plurality of boilers 20. Thus, the boiler 20 can change the steam amount in units of the unit steam amount U in the range from the minimum combustion state S1 to the maximum combustion state S2.

The unit steam amount U can be appropriately set according to the steam amount (maximum steam amount) in the maximum combustion state S2 of the 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%.
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.

The boiler group 2 is set with a standby steam amount for setting a predetermined number of boilers 20 among the plurality of boilers 20 as standby control boilers that perform standby control. In addition, standby control means controlling to be able to shift to the steaming preparation state, and the boiler 20 that is set as the standby control boiler and is not combusted transitions to the steaming preparation state as necessary. become.
The standby steam amount can be set arbitrarily, but in the present embodiment, as an example, the steam usage amount of the steam use facility 18 at the normal time, that is, the steam usage amount corresponding to the required load in the steady state of the boiler system 1. Is set as the standby steam amount. Note that the amount of steam used according to the steady-state required load has a predetermined range, but when setting the amount of steam used according to the steady-state required load as the standby steam amount, It is preferable to set the upper limit value or the steam use amount near the upper limit value as the standby steam amount rather than the center value.

The boiler group 2 is set with a stop reference threshold and an increase reference threshold for determining the number of boilers 20 to burn. The stop reference threshold is a threshold used when reducing the number of boilers 20 that burn, and the increase reference threshold is a threshold used when increasing the number of boilers 20 that burn. In the present invention, the stop reference threshold value and the increase reference threshold value can be arbitrarily set, but in the present embodiment, as an example, the load factor that reduces the number of boilers 20 that burn as the stop reference threshold value. A certain load reduction rate is adopted, and a fluctuation steam amount, which is a steam amount prepared as a reserve power to be increased in a short time in response to a sudden load fluctuation, is adopted as an increase reference threshold.
That is, when the load factor of the boiler 20 in the combustion state reaches the reduced load factor (below or becomes smaller), the combustion of one of the boilers 20 in the combustion state is stopped. Further, when the sum of the remaining capacity of the boiler 20 that is burning (the difference between the maximum steam amount and the output steam amount of the boiler 20) is equal to or less than the variable steam amount (or smaller), the stopped boiler 20 is combusted. To start.

  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. 2, when priority of “1” to “5” is assigned to each of the No. 1 boiler to the No. 5 boiler of the boiler 20, the No. 1 boiler has the highest priority. Has the lowest priority. 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.

Next, details of the control of the number control device 3 according to the present embodiment will be described.
When the amount of steam used in the steam using facility 18 is less than the standby steam amount (normal amount of steam used), the steam used in the steam using facility 18 is expected to increase thereafter. It is preferable to shift to the steaming preparation state. On the other hand, when the steam usage amount in the steam usage facility 18 exceeds the standby steam amount, the steam usage amount in the steam usage facility 18 is predicted to decrease thereafter, so that the boiler 20 in the combustion stop state is shifted to the steam supply preparation state. There is no need to let them.
The number control device 3 of the present embodiment shifts the unburned boiler 20 to the steam supply preparation state only in a state where such an increase in the future steam usage is expected, thereby removing the unnecessary boiler 20. The transition to the steaming preparation state is to be prevented.

  Hereinafter, this will be described in detail with reference to FIG. FIG. 3 is a block diagram illustrating a functional configuration of the control unit 4. The control unit 4 includes a standby control boiler setting unit 41, a boiler control unit 42, and a standby control unit 43.

The standby control boiler setting unit 41 sets, as standby control boilers, a predetermined number of boilers 20 in which the sum of the boiler capacities satisfies the standby steam amount among the plurality of boilers 20 regardless of whether or not they are combusting. Specifically, the standby control boiler setting unit 41 adds the boiler capacity in order from the boiler 20 having the highest priority until the standby steam amount becomes equal to or higher than the standby steam amount, and adds until the sum of the boiler capacities becomes equal to or higher than the standby steam amount. The fired boiler 20 is set as a standby control boiler.
The standby control boiler setting unit 41 sets a standby control boiler from among the plurality of boilers 20 each time the priority order is changed.

  The boiler control unit 42 burns the boiler 20 according to the required load. That is, the boiler control unit 42 monitors the fluctuation of the required load from the steam pressure inside the steam header 6, and from the boiler 20 having a high priority so that the amount of steam corresponding to the required load is generated from the boiler group 2. The boiler 20 is burned in order.

The standby control unit 43 performs standby control on the boiler 20 set as the standby control boiler among the non-burning boilers 20 and maintains the boilers 20 other than the standby control boiler in the combustion stopped state. In addition, the boiler 20 which is not combusting is synonymous with the boiler 20 which is not supplying steam to the steam header 6, and includes the boiler 20 in which standby control is performed, and the boiler 20 in a combustion stop state.
Moreover, as standby control, the control which transfers to a steaming preparation state from a combustion stop state can be considered, for example. At this time, when there are a plurality of boilers 20 set as standby control boilers among the non-burning boilers 20, the standby control unit 43 selects only the boiler 20 having a higher priority among the plurality of boilers 20. It is good also as making it transfer to a steaming preparation state, and good also as making all these several boilers 20 transfer to a steaming preparation state.

  Next, operation | movement of the boiler system 1 of this embodiment is demonstrated, referring FIG. FIG. 4 is a diagram illustrating an example of the operation of the boiler system 1. In FIG. 4, each of the plurality of boilers 20 is assumed to have a boiler capacity of 7000 kg / h and a standby steam amount of 21000 kg / h. In addition, it is assumed that the priorities of “1” to “5” are assigned to the plurality of boilers 20 in the order of No. 1 boiler to No. 5 boiler, respectively.

Referring to FIG. 4 (1), standby control boiler setting unit 41 sets the number of boilers 20 corresponding to the standby steam amount among five boilers 20 as standby control boilers. In FIG. 4 (1), when the boiler capacity is added from the No. 1 boiler with the priority “1” to the No. 3 boiler with the priority “3”, the standby steam amount exceeds the standby steam amount. Three units of boilers to No. 3 boilers are set as standby control boilers.
When the standby control boiler setting unit 41 sets the No. 1 boiler to the No. 3 boiler as the standby control boiler, the standby control unit 43 controls the standby for the No. 1 boiler to the No. 3 boiler, for example, the No. 1 boiler to the No. 3 boiler. Transition from the combustion stop state to the steaming preparation state. Moreover, the standby control boiler setting unit 41 maintains the No. 4 boiler and the No. 5 boiler that are not standby control boilers in a combustion stopped state.

Referring to FIG. 4 (2), when the steam using facility 18 starts using steam, the boiler control unit 42 burns the boiler 20 according to the required load of the steam using facility 18. In FIG. 4 (2), the boiler control unit 42 supplies the steam amount corresponding to the required load from the No. 1 boiler to the steam header 6 by burning the No. 1 boiler having the priority “1”.
Here, since the boiler capacity of the No. 1 boiler is smaller than the standby steam amount, the steam usage amount of the steam use facility 18 is expected to increase in the future. Therefore, the standby control unit 43 performs standby control on the No. 2 and No. 3 boilers set as standby control boilers among the No. 2 to No. 5 boilers that are not combusting. Moreover, since the sum of the boiler capacities of the No. 1 boiler to the No. 3 boiler is equal to or greater than the standby steam amount, if steam is supplied from the No. 1 boiler to the No. 3 boiler to the steam header 6, the steam of the steam using facility 18 at normal time Can cover the amount used. Therefore, the standby control unit 43 maintains the No. 4 boiler and the No. 5 boiler that are not standby control boilers in a combustion stopped state.

Referring to FIG. 4 (3), when the amount of steam used by the steam using facility 18 increases, the boiler control unit 42 burns the No. 2 boiler with the priority “2” following the No. 1 boiler. At this time, since the No. 2 boiler is in a steamable state by the standby control of the standby control unit 43, steam can be supplied to the steam header 6 immediately after the boiler control unit 42 gives a combustion instruction.
Moreover, since the sum of the boiler capacities of the No. 1 boiler and the No. 2 boiler is smaller than the standby steam amount, the steam usage amount of the steam use facility 18 is expected to increase in the future. Therefore, the standby control unit 43 performs standby control on the No. 3 boiler set as the standby control boiler among the No. 3 boiler to No. 5 boiler that is not burning, and the No. 4 boiler that is not the standby control boiler and Maintain the No. 5 boiler with the combustion stopped.

Referring to FIG. 4 (4), when the amount of steam used in the steam using facility 18 further increases, the boiler control unit 42 burns the No. 3 boiler with the priority “3” following the No. 1 and No. 2 boilers. Let Similarly to the No. 2 boiler, the No. 3 boiler is also in a steamable state by the standby control of the standby control unit 43, so that steam can be supplied to the steam header 6 immediately after the combustion instruction of the boiler control unit 42. it can.
In addition, since the sum of the boiler capacities of the No. 1 boiler to the No. 3 boiler is equal to or greater than the standby steam amount, the steam usage amount of the steam use facility 18 is expected to fall within a substantially constant range in the future. Therefore, the standby control unit 43 maintains the No. 4 boiler and the No. 5 boiler in the combustion stopped state without executing standby control for the No. 4 boiler and the No. 5 boiler that are not combusting.

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

  (1) The standby steam amount is set in the boiler group 2, and the control unit 4 sets the number of boilers whose sum of boiler capacities is equal to or greater than the standby steam amount as standby control boilers. As long as it is possible to shift to the steaming preparation state. According to such a configuration, since the standby control boiler can be shifted to the steam supply preparation state in a low load state that does not satisfy the standby steam amount, it is possible to appropriately cope with an expected increase in required load. it can. On the other hand, since only the amount of steam corresponding to the standby steam amount is prepared so that steaming is possible, even the unnecessary boiler 20 is not shifted to the steaming preparation state, and fuel consumption can be suppressed. As a result, according to the boiler system 1 of the present embodiment, it is possible to appropriately control the number of boilers 20 that shift to the steaming preparation state.

  (2) Moreover, the priority order is set to the plurality of boilers 20, and the control unit 4 sets a predetermined number of boilers 20 as standby control boilers in order from the boiler 20 having the highest priority order. It was set as the structure burned in an order from the high boiler 20. FIG. According to such a configuration, the standby control boiler may be included in the non-burning boiler 20 in the low load state where the standby steam amount is less than the standby steam amount, whereas the combustion is performed in the high load state exceeding the standby steam amount. No boiler 20 includes a standby control boiler. Therefore, the boiler 20 which has stopped combustion after reaching the high load state does not shift to the steaming preparation state, and fuel consumption accompanying unnecessary transition to the steaming preparation state can be suppressed.

  The preferred embodiments of the boiler system 1 of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and can be modified as appropriate.

In the said embodiment, although the boiler capacity | capacitance of the several boiler 20 is made the same (7000 kg / h), this invention is not limited to the boiler 20 of the same boiler capacity | capacitance, Each is a boiler with a different boiler capacity | capacitance. 20 can be applied. That is, according to the present invention, a predetermined number of boilers 20 in which the sum of boiler capacities becomes the standby steam amount is set as standby control boilers. Even if the boiler capacities of the respective boilers 20 are different, an appropriate number of boilers 20 is set. It can be set as a standby control boiler.
This point will be specifically described. For example, the boiler capacity of the No. 1 boiler is “2000 kg / h”, the boiler capacity of the No. 2 boiler is “3000 kg / h”, the boiler capacity of the No. 3 boiler is “4000 kg / h”, and the boiler capacity of the No. 4 boiler is “5000 kg”. / H ", the boiler capacity of the No. 5 boiler is" 6000 kg / h ", and" 10000 kg / h "is set as the standby steam amount. At this time, in the situation where the priorities “1” to “5” are set in the order of No. 1 boiler to No. 5 boiler, four boilers of No. 1 boiler to No. 4 boiler are set as standby control boilers. (2000 + 3000 + 4000 + 5000 = 14000 kg / h). On the other hand, in the situation where priority levels “1” to “5” are set in the order of the No. 5 boiler to the No. 1 boiler, the two boilers of the No. 5 boiler and the No. 4 boiler are set as standby control boilers. (6000 + 5000 = 11000 kg / h).
Thus, even when the boiler capacities of the plurality of boilers 20 are different, an appropriate number of boilers 20 can be set as standby control boilers.
Of course, it is not necessary that the boiler capacities of all the boilers 20 among the plurality of boilers 20 are different, the boiler capacities of at least one boiler 20 among the plurality of boilers 20 are different, and the boiler capacities of the other boilers 20 are the same. Also good.

  Moreover, in the said embodiment, although it is supposed that the some boiler 20 is comprised with a proportional control boiler, the boiler 20 is good also as not only a proportional control boiler but with a step value control boiler. The stage value control boiler has a plurality of staged combustion positions, and controls the amount of combustion by selectively turning on / off combustion, adjusting the size of the flame, etc. It is a boiler that can increase or decrease the amount of combustion in stages according to the selected combustion position. As an example, the plurality of boilers 20 may be configured by a three-position boiler having three positions, a combustion stop position, a low combustion position, and a high combustion position. Of course, the boiler 20 is not limited to three positions, and may have arbitrary N positions of combustion positions.

  Moreover, 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, you may apply this invention to a boiler system provided with the boiler group which consists of 2-4 or 6 or more boilers.

  Further, in the present embodiment, the boiler 20 is controlled by changing the combustion state between the combustion stop state S0 and the minimum combustion state S1 by turning on / off the combustion of the boiler 20, and the maximum combustion from the minimum combustion state S1. In the range of state S2, although comprised with the proportional control boiler which can control a combustion amount continuously, it is not restricted to this. That is, the boiler may be configured by a proportional control boiler that can continuously control the combustion amount in the entire range from the combustion stop state to the maximum combustion state.

  Moreover, in this embodiment, although the total value of the evaporation amount output from each of the some boiler 20 was made into the output evaporation amount of the boiler group 2, it is not restricted to this. That is, the total value of the commanded evaporation amount, which is the evaporation amount calculated from the combustion instruction signal transmitted from the number control device 3 (control unit 4) to the plurality of boilers 20, may be handled as the output evaporation amount of the boiler group 2. .

DESCRIPTION OF SYMBOLS 1 Boiler system 2 Boiler group 20 Boiler 4 Control part 41 Standby control boiler setting part 42 Boiler control part 43 Standby control part

Claims (2)

A boiler system including a boiler group including a plurality of boilers capable of burning by changing a load factor, and a control unit that controls a combustion state of the boiler group,
At least one of a plurality of boilers included in the boiler group is a different capacity boiler having a different capacity from other boilers,
Priorities are set for the plurality of boilers,
In the boiler group, a standby steam amount is set,
The controller is
A standby control boiler that sets, as a standby control boiler, a predetermined number of boilers whose sum of boiler capacities satisfies the standby steam amount in order from the boiler with the highest priority , regardless of whether or not they are burning. A setting section;
A boiler control unit for burning the boiler according to a required load;
Among the non-burning boilers, the boiler set as the standby control boiler is shifted to the steaming preparation state, and the standby control unit for maintaining the boilers other than the standby control boiler in the combustion stopped state;
Boiler system equipped with. The boiler control unit burns in order from the boiler with the highest priority,
The boiler system according to claim 1.

Images