JP5455165B2 - Program, controller and boiler system - Google Patents

Description

The present invention relates to a program for controlling a boiler group composed of a plurality of boilers, a controller, and a boiler system.

As is well known, it consists of a plurality of boilers as a technology for suppressing wasteful combustion in steam generation and reducing loss at the time of boiler start / stop by increasing or decreasing the combustion amount of the boiler stepwise according to the required load A technique for generating steam by a boiler group is used.
Regarding the control of the boiler group, the number of combustion positions of each boiler and the difference evaporation amount that increases or decreases when the combustion position is shifted by one stage are the same (for example, the combustion amount of low combustion: the combustion amount of high combustion is 1: 2). (See, for example, Patent Document 1).

  In the control of such a boiler group, when the low combustion boiler is transferred to the high combustion boiler, as shown in FIG. 9, for example, No. 1 in the low combustion state (500 kg / h). No. 4 boiler stopped combustion and was in a low combustion state (600 kg / h). There are cases where the two boilers are shifted to a high combustion state (1600 kg / h).

JP-A-10-227402

  However, as shown in FIG. 9, for example, when there are boilers having different maximum combustion amounts in the boiler group, No. 1 in the low combustion state (500 kg / h) as described above. No. 4 No. 4 boiler stopped burning and was in a low combustion state (600 kg / h). When the two boilers are shifted to a high combustion state (1600 kg / h), the evaporation amount as a boiler group increases from (3600 kg / h) to (4100 kg / h), and the total evaporation amount of the boiler group greatly fluctuates. Supply may become unstable.

The present invention has been made in consideration of such circumstances, and for at least any one of a plurality of boilers constituting a boiler group, any one of the maximum combustion amount, the turndown ratio, and the number of combustion positions. Is different from other boilers, or when the turndown ratio is other than 1.0, stable steam supply even if the combustion state of the boiler group (the combination of the boiler to be burned in the boiler group and its combustion position) is changed An object of the present invention is to provide a program, a controller, and a boiler system that control a group of boilers that can be used.

In order to solve the above problems, the present invention proposes the following means.
The invention according to claim 1 includes a plurality of boilers that increase or decrease the combustion amount in stages, and the difference evaporation amount that increases or decreases when one of the combustion positions of at least one boiler is shifted to one stage is different from that of another boiler. Is a program for controlling a boiler group configured differently from the differential evaporation amount that increases or decreases when one of the combustion positions is shifted to one stage, and is a total evaporation totaling the evaporation amounts of the boilers in the boiler group When the amount or the physical amount corresponding to the total evaporation amount is maintained for a predetermined time, the total evaporation amount is maintained within a predetermined range, and the combination of the boiler to be burned in the boiler group and its combustion position is changed. It is configured.

  A tenth aspect of the present invention is a controller, comprising the program according to any one of the first to eighth aspects.

  The invention described in claim 11 is a boiler system, comprising the controller described in claim 9.

Program according to the present invention, the controller, according to Boirashisute arm, in a boiler group difference evaporation amount with different boiler, a physical quantity corresponding to the total evaporation amount or the total amount of evaporation of boiler group is maintained for a predetermined time constant In this state, for example, combustion efficiency, followability, and the like can be improved while maintaining the total evaporation amount within a predetermined range.

In this specification, the difference evaporation amount means an evaporation amount that increases when the boiler is moved to a higher combustion position, that is, an evaporation amount at the combustion position after the transition and a combustion stop position (or combustion before the transition). The difference between the position and the amount of evaporation.
Further, the amount of evaporation that increases by moving up one level and becoming the Nth combustion position (N is an integer equal to or greater than 1) is expressed as “the difference evaporation amount at the Nth combustion position” or “the Nth difference evaporation amount”. For example, the amount of evaporation that increases when shifting from the combustion stop position to the first combustion position is referred to as “difference evaporation amount of the first combustion position” or “first difference evaporation amount” and the first combustion position. The amount of evaporation that increases when shifting to the second combustion position is referred to as “the difference evaporation amount at the second combustion position” or “the second difference evaporation amount”.

  The invention according to claim 2 includes a plurality of boilers that increase or decrease the combustion amount in stages, and at least one boiler has a maximum combustion amount, a turndown ratio (maximum combustion amount / minimum combustion amount), and the number of combustion positions. A program for controlling a boiler group having a configuration different from that of other boilers, at least in any one of the above, and a total evaporation amount obtained by summing evaporation amounts of boilers in the boiler group or a physical amount corresponding to the total evaporation amount However, when maintained for a predetermined time, the total evaporation amount is maintained within a predetermined range, and the combination of the boiler to be burned in the boiler group and its combustion position is changed.

According to program according to the present invention, the maximum combustion amount of one boiler turndown ratio (maximum combustion amount / minimum combustion amount), at least one different boiler group combustion position number, the total amount of evaporation of boiler group Alternatively, when the physical quantity corresponding to the total evaporation amount is maintained for a predetermined time to reach a steady state, it is possible to improve, for example, combustion efficiency and followability while maintaining the total evaporation amount within a predetermined range.

  Invention of Claim 3 is a program of Claim 1 or Claim 2, Comprising: The combination of the boiler burned in the said boiler group, and its combustion position is transferred to the preferential combustion position set beforehand. It is comprised by these.

According to program according to the present invention, the boiler and combinations thereof combustion positions is burned in boiler group, for example, combustion efficiency, since the transition to combustion position that is dominant preset respect tracking resistance, the boiler group It is possible to appropriately control the operating state in accordance with the fluctuation of the required load.

  Invention of Claim 4 is a program of Claim 3, Comprising: As for the boiler which comprises the said boiler group, combustion in the lowest combustion position is more efficient than combustion in the highest combustion position A boiler at any one of the uppermost combustion positions is moved to the lowermost combustion position and another stopped boiler is moved to the lowermost combustion position. To do.

According to program according to the present invention, when the lowest combustion position is higher combustion efficiency than the uppermost combustion position, the combustion efficiency of the boiler group by migrating boiler at the top combustion position to the lowest combustion position Can be improved.

  Invention of Claim 5 is a program of Claim 3, Comprising: As for the boiler which comprises the said any boiler group, combustion in the highest combustion position is more efficient than combustion in the lowest combustion position In this case, the boiler at any one of the lowest combustion positions is moved to the highest combustion position and the other boilers at the lowest combustion position are stopped.

According to program according to the present invention, when the uppermost combustion position is higher combustion efficiency than the lowest combustion position, the boiler at the lowest combustion position is shifted to the uppermost combustion position the combustion efficiency of the boiler unit Can be improved.

  Invention of Claim 6 is a program of Claim 3, Comprising: The boiler which comprises the said boiler group in the middle combustion position in which it exists between the highest combustion position and the lowest combustion position If combustion is more efficient than the highest and lowest combustion positions, and there is at least one of the boiler at the highest combustion position or the boiler at the lowest combustion position, one of these boilers Is configured to shift to any one of the intermediate combustion positions having higher efficiency than the uppermost combustion position and the lowermost combustion position.

According to program according to the present invention, when the median combustion position is higher combustion efficiency than the uppermost combustion position and the lowermost combustion position, a high one boiler at the top combustion position and the lowermost combustion positions Since it shifts to the middle combustion position, which is regarded as efficient, the combustion efficiency of the boiler group can be improved.

  Invention of Claim 7 is a program of Claim 3, Comprising: The boiler which comprises the said boiler group is a some middle combustion position between the highest combustion position and the lowest combustion position. And the combustion efficiency at any of the intermediate combustion positions is higher than that of the uppermost combustion position and the lowermost combustion position. It is configured to shift from the intermediate combustion position to another intermediate combustion position where the combustion efficiency is high.

According to program according to the present invention, a boiler constituting one of the boiler group has a plurality of intermediate combustion position between the uppermost combustion position and the lowermost combustion position, and any medium When the combustion efficiency at the combustion position is higher than the uppermost combustion position and the lowermost combustion position, it shifts from one intermediate combustion position to the intermediate combustion position where the combustion efficiency is high. The combustion efficiency of the boiler group can be improved.

  Invention of Claim 8 is a program of any one of Claim 1-7, Comprising: The priority is set to the boiler burned in the said boiler group, and its combustion position, The said priority Based on the above, it is configured to change the combination of the boiler to be burned in the boiler group and its combustion position.

According to program according to the present invention, it sets the priority to the boiler and combustion position, since changing the boiler, and combinations thereof combustion positions is burned in a boiler group based on this priority, boiler group of combustion efficiency, Followability and the like can be improved easily and efficiently.

  The invention according to claim 9 is the program according to any one of claims 1 to 8, wherein there are a plurality of combinations of boilers to be burned in the boiler group within the predetermined range and their combustion positions. When the total evaporation amount or the physical amount corresponding to the total evaporation amount is maintained above a set value, the boiler group is configured to reduce the total evaporation amount within the predetermined range. When the combination of the boiler to be burned and the combustion position thereof is changed, and the physical amount corresponding to the total evaporation amount or the total evaporation amount is maintained below a set value, the total evaporation amount within the predetermined range The boiler group is configured to change the combination of the boiler to be burned and its combustion position so as to be large.

According to program according to the present invention, the physical quantity corresponding to the total evaporation amount or total evaporation amount, the total amount of evaporation when exceeds the set value is reduced within a predetermined range, is maintained below the set value If so, the combination of the boiler to be burned in the boiler group and its combustion position is changed so as to increase the total evaporation amount within a predetermined range, so that the difference between the required evaporation amount and the total evaporation amount can be reduced. .

Program according to the present invention, the controller and according to Boirashisute arm, boiler group having any one of the boiler boiler is other than turndown ratio other and the differential evaporation amount have different combustion positions 1.0 Can provide a stable steam supply.

It is a figure showing a schematic structure of a boiler system concerning a 1st embodiment of the present invention. It is a figure explaining an example of the database composition with which the control part concerning a 1st embodiment is provided, (A) is an example when a low combustion state is high efficiency, (B) is a case where a high combustion state is high efficiency An example is shown. It is a figure which shows an example of the flowchart which concerns on the program of this invention. It is a conceptual diagram explaining the effect | action of the boiler system which concerns on 1st Embodiment, and is a figure which shows the example at the time of using the database of FIG. 2 (A). It is a conceptual diagram explaining the effect | action of the boiler system which concerns on 1st Embodiment, and is a figure which shows the example at the time of using the database of FIG. 2 (B). It is a figure which shows schematic structure of the boiler system which concerns on the 2nd Embodiment of this invention. It is a figure explaining an example of a database structure in case the middle combustion state with which the control part concerning a 2nd embodiment is provided is highly efficient. It is a conceptual diagram explaining the effect | action of the boiler system which concerns on 2nd Embodiment. It is a conceptual diagram explaining operation | movement of the conventional boiler system.

The first embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 is a diagram showing a first embodiment of a boiler system according to the present invention, and reference numeral 1 denotes a boiler system.

The boiler system 1 detects a boiler group 2 composed of a plurality of boilers, a control unit (controller) 4, a steam header 6, and a steam pressure (a physical quantity corresponding to the evaporation amount) in the steam header 6. The pressure sensor 7 is provided, and the steam generated in the boiler group 2 is supplied to the steam using facility 18.
In this embodiment, the required load is the amount of evaporation corresponding to the amount of steam consumed in the steam using facility 18, and the amount of evaporation of the boiler group 2 based on the pressure of the steam in the steam header 6 detected by the pressure sensor 7 described above. Is to control.

The boiler group 2 includes, for example, five steam boilers, and includes a first boiler 21, a second boiler 22, a third boiler 23, a fourth boiler 24, and a fifth boiler 25.
In this embodiment, the first boiler 21,..., The fifth boiler 25 are three controllable to three (two or more) stepwise combustion states of a combustion stop state, a low combustion state, and a high combustion state, respectively. The position boiler is configured such that the low combustion state corresponds to the first combustion position (lowest combustion position) and the high combustion state corresponds to the second combustion position (highest combustion position).

  In this embodiment, each boiler is set with an evaporation amount (a generated steam amount) when burning at each combustion position, and an evaporation amount when each boiler is burning at the jth combustion position is set. For example, in the boiler group 2, the evaporation amount when each boiler is burning at the second combustion position may be described as “rated evaporation amount”. .

Further, the differential evaporation amount at the jth combustion position (j = 1, 2) of the i (= 1,..., 5) th boiler is denoted as J (i, j). The sum of the differential evaporation amounts J (i, j) up to the j combustion position is referred to as the total evaporation amount G (i, j) up to the jth combustion position of the i-th boiler.
Further, the sum of the total evaporation amount G (i, j) of the boilers burning in the boiler group 2, that is, the total evaporation amount of the boiler group 2 may be denoted by E.

  Moreover, the 1st boiler 21, ..., the 5th boiler 25 in this embodiment respond | corresponds with i (= 1, ..., 5), for example, J (1, 1) is a 1st boiler. 21, G (1,2) represents the total evaporation amount up to the second combustion position in the first boiler 21, that is, the rated evaporation amount of the first boiler 21.

In this embodiment, the difference evaporation amount J (i, j) and the combined evaporation amount G (i, j) at each combustion position of the first boiler 21 to the fifth boiler 25 are as follows (the unit is, for example, (Kg / h).). In the following table, the item described as J (i, 1) means the first combustion position of the i-th boiler.
<Differential evaporation amount and rated evaporation amount at each combustion position of boilers constituting boiler group 2>
J (i, 1) J (i, 2) G (i, 2)
First boiler 21 1000 1000 2000
Second boiler 22 600 1000 1600
Third boiler 23 500 1300 1800
4th boiler 24 500 1200 1700
5th boiler 25 1800 2000 3800

  The control unit 4 includes an input unit 41, a memory 42, a calculation unit 43, a hard disk 44, an output unit 46, and a communication line 47, and includes an input unit 41, a memory 42, a calculation unit 43, a hard disk 44, and an output. The units 46 are connected to each other via a communication line 47 so that data and the like can be communicated with each other, and a database 45 is stored in the hard disk 44.

The input unit 41 includes, for example, a data input device such as a keyboard (not shown) and can output settings and the like to the calculation unit 43. The pressure sensor 7, the boilers 21,... 13. Connected by the signal line 16, and outputs the pressure signal input from the pressure sensor 7 and the signals input from the boilers 21,..., 25 (for example, information such as the combustion position) to the calculation unit 43. It has become.
The output unit 46 is connected to the boilers 21,..., 25 by the signal line 14, and outputs the control signal output from the calculation unit 43 to the boilers 21,.

  The calculation unit 43 reads and executes a program stored in a storage medium (for example, ROM) of the memory 42 to calculate the evaporation amount corresponding to the required load, the combination of the boilers to be burned in the boiler group 2 and their combustion positions. Based on the result of the selection, a control signal is output to the boilers 21,..., 25 via the output unit 46.

The database 45 includes a first database 45A and a second database 45B.
In the first database 45A, a data table indicating the relationship between the pressure signal (mV) and the pressure (Pa) is stored as numerical data. Based on the pressure signal (mV) from the pressure sensor 7, the first header 45A includes The pressure (Pa) is calculated.

  For example, as shown in FIG. 2, the second database 45B includes “differential evaporation amount at each combustion position” and “each” corresponding to the first combustion position and the second combustion position of each boiler 21,. A data table of “combustion efficiency η (i, j) at the combustion position” is stored as numerical data. Note that the combustion efficiency η (i, j) shown in FIG. 2 is set to a value lower than the actual value for the sake of convenience in order to easily explain the operation and effect of the invention.

The program according to the first embodiment includes steady state detecting means and combustion state changing means.
The steady state detecting means is adapted to determine that the steam pressure in the steam header 6 is maintained within a set pressure range for a predetermined time by the steam generated by the boiler group 2, and the combustion state changing means is In the boiler group 2, a combination of a boiler to be burned and a combustion position thereof (including transition to a combustion stop state and boiler combustion stop, the same applies hereinafter) is selected, and a control signal is sent to each boiler 21,. The combustion state of the boiler group 2 is changed by outputting.

  Further, the combustion state changing means is configured so that the combination of the boiler to be burned in the boiler group 2 and its combustion position is superior with respect to the combustion efficiency, that is, the combustion efficiency is increased by the setting signal input from the input unit 41. The boiler group 2 is configured to select a combination of a boiler to be burned and its combustion position.

Next, the program according to the first embodiment will be described with reference to FIG.
FIG. 3 is a flowchart showing an example of a program for executing a change in the combustion state of the boiler group 2 according to the first embodiment. In this flowchart, the steady state detection means is composed of S3 to S7 and S11, and the combustion state change means is composed of S8 to S10.

1) First, the pressure range (for example, target value, upper limit value, lower limit value) P (R) to be maintained in the steam header 6 and the range of total evaporation to be output by the boiler group 2 (for example, target value, upper limit value) Value, lower limit value) E (R), and set time (predetermined time) TS for maintaining the pressure range P (R) related to the trigger for changing the combustion state of the boiler group 2 are set. (S1)
2) The operation of the boiler group 2 is started, and the pressure is increased to the pressure range P (R) in which the steam header 6 should be maintained. (S2)
3) It is determined whether the boiler group 2 is in operation. (S3)
When the boiler group 2 is in operation, the process proceeds to S4, and when the boiler group 2 is stopped, the execution of the program is terminated.
4) The pressure signal of the pressure sensor 7 is converted into the pressure P in the steam header 6 with reference to the first database 45A. (S4)
5) Count up the counter CTR. (S5)
6) It is determined whether or not the pressure P is within the pressure range P (R). (S6)
If the pressure P is not within the pressure range P (R), the process proceeds to S11, the counter CTR is reset and the process proceeds to S3, and if the pressure P is within the pressure range P (R), the process proceeds to S7.
7) It is determined whether the numerical value of the counter CTR (elapsed time t after the start of counting) has reached the set time TS. (S7)
If the counter CTR has not reached the set time TS, the process proceeds to S3, and if the counter CTR has reached the set time TS, the process proceeds to S8 to change the combustion state of the boiler group 2.
8) Calculate (create) a combination of boilers to be burned in the boiler group 2 and their combustion positions such that the total evaporation amount E falls within the total evaporation amount range E (R) with reference to the second database 45B. At the same time, the combustion efficiency in the combination is calculated. (S8)
When the execution of S8 ends, the process proceeds to S9.
For combinations of boilers and their combustion positions in the boiler group 2, the total evaporation amount E is calculated for all possible combinations, and the total evaporation amount E falls within the total evaporation amount range E (R). Create a list of things.
Moreover, the calculation of the combustion efficiency in S8 is based on the data table stored in the 2nd database 45B, for example, the difference evaporation amount J (i, j) of the boiler which comprises the combustion state of the boiler group 2, and its combustion position And the weighted average of the combustion efficiency η (i, j). For example, the combustion efficiency of the following numerical formula boiler group 2 = (sum of the difference evaporation amount at the burning combustion position) / ( (Total of (Evaporation difference at combustion position) / (Combustion efficiency at that combustion position)))
by.
9) From the list created in S8, a combination (for example, having the highest combustion efficiency) that is dominant in the combustion state of the boiler group 2 is selected. (S9)
10) A control signal for changing the combustion state is output based on the result selected in S9. (S10) When a control signal for changing the combustion state is output, the process proceeds to S3.

Next, the operation of the boiler system 1 when the combustion efficiency of each of the boilers 21, ..., 25 is higher at the first combustion position than at the second combustion position will be described. For convenience, the range E (R) of the total evaporation amount of the boiler group 2 is, for example, a lower limit 3550 (kg / h) and an upper limit 3650 (kg / h), and the total evaporation E is 3600 (kg). / H) only.
1) First, as shown in FIG. 4A, in the boiler group 2 before changing the combustion state, the first boiler 21 and the second boiler 22 are combusting in a high combustion state, and the total evaporation E is 3600. Suppose that the pressure in the steam header 6 is maintained in the pressure range P (R) for a predetermined time TS in this state. As a result, the calculation unit 43 executes the combustion state changing means of the program.
2) The calculation unit 43 refers to the second database 45B, and the total evaporation amount E of the boiler group 2 is within the total evaporation amount range E (R) (3550 (kg / h) to 3650 (kg / h). A list of “combinations of boilers and combustion positions to be burned in the boiler group 2” is created, and the combustion efficiency of the boiler group 2 in the combination is temporarily associated with the combination of the list in the memory 42. Store.
In this boiler group 2, the combination in which the total evaporation amount E is within the total evaporation amount range E (R) (in this case, 3600 (kg / h)) includes W11 in the current combustion state,
W11 = J (1,1) + J (1,2) + J (2,1) + J (2,2)
W12 = J (1,1) + J (1,2) + J (2,1) + J (3,1) + J (4,1)
W13 = J (1,1) + J (2,1) + J (2,2) + J (3,1) + J (4,1)
W14 = J (3,1) + J (3,2) + J (5,1)
There are four ways. (In addition, 11-14 attached | subjected to W are the codes | symbols for identification.)
The combustion efficiencies η11, η12, η13, and η14 in each case of W11, W12, W13, and W14 are calculated by a weighted average with reference to the data table of the second database 45B (FIG. 2A). The above η11 to η14 indicate the combustion efficiency of the boiler group corresponding to W11 to W14, and η (i, j) shown below corresponds to J (i, j) in the second database 45B. Shows the combustion efficiency.
For example, the combustion efficiency η11 in the case of W11 is
η11 = (J (1,1) + J (1,2) + J (2,1) + J (2,2)) / (((J (1,1) / η (1,1)) + (J ( 1,2) / η (1,2)) + (J (2,1) / η (2,1)) + (J (2,2) / η (2,2)))
= (1000 + 1000 + 600 + 1000) / ((1000 / 0.95) + (1000 / 0.92) + (600 / 0.95) + (1000 / 0.90)))
= 0.9273 = 92.73%.
Similarly, η12 = 94.85%, η13 = 93.56%, and η14 = 93.13%.
3) Next, the calculation unit 43 selects the combination having the highest combustion efficiency of the boiler group 2 from the list stored in the memory 42. Here, W12 is selected.
4) Next, the calculation unit 43 shifts the second boiler 22 from the high combustion state to the low combustion state and moves the third boiler 23 and the fourth boiler 24 in order to shift the boiler group 2 to the combustion state related to W12. A control signal for shifting from the combustion stop state to the low combustion state is output to each boiler via the output unit 46.
5) As a result, the combustion state of the boiler group 2 is changed as shown in FIG. Further, the total evaporation E after the change is 3600 (kg / h) which is the same as before the change of the combustion state.

  According to the boiler system 1, when the first combustion position, which is the lowest combustion position, has a higher combustion efficiency than the second combustion position, which is the highest combustion position, some boilers at the second combustion position are The combustion efficiency of the boiler group 2 is maintained while maintaining the total evaporation E of the boiler group 2 by shifting to the first combustion position and setting the low combustion state, and if necessary, setting the boiler in the combustion stop state to the low combustion state. Can be improved.

Next, the operation of the boiler system 1 when the combustion efficiency of the boilers 21,..., 25 is higher at the second combustion position than at the first combustion position will be described. The total evaporation amount range E (R) of the boiler group 2 is the same as described above.
In this case, the combustion efficiency of each of the boilers 21,..., 25 is set higher at the second combustion position than at the first combustion position, as shown in FIG.
1) First, as shown in FIG. 5A, in the boiler group 2 before changing the combustion state, the first boiler 21 is in a high combustion state, the second boiler 22, the third boiler 23, and the fourth boiler 24 are It is assumed that the total evaporation amount E is 3600 (kg / h) by burning in the low combustion state, and the pressure in the steam header 6 is maintained in the pressure range P (R) for a predetermined time TS in this state. As a result, the calculation unit 43 executes the combustion state changing means of the program.
2) The calculation unit 43 refers to the second database 45B, and the total evaporation amount E of the boiler group 2 is within the total evaporation amount range E (R) (3550 (kg / h) to 3650 (kg / h). A list of “combinations of boilers and combustion positions to be burned in the boiler group 2” is created, and the combustion efficiency of the boiler group 2 in the combination is temporarily stored in the memory 42 in association with the list combination. .
In the boiler group 2, the combination in which the total evaporation amount E is within the total evaporation amount range E (R) (in this case, 3600 (kg / h)) includes W22 in the current combustion state,
W21 = J (1,1) + J (1,2) + J (2,1) + J (2,2)
W22 = J (1,1) + J (1,2) + J (2,1) + J (3,1) + J (4,1)
W23 = J (1,1) + J (2,1) + J (2,2) + J (3,1) + J (4,1)
W24 = J (3,1) + J (3,2) + J (5,1)
There are four ways.
When the combustion efficiencies η21, η22, η23, and η24 in the case of W21, W22, W23, and W24 are calculated with reference to the data table (FIG. 2B) of the second database 45B, η21 = 93.64%, η22 = 92.81%, η23 = 92.81%, and η24 = 93.06%.
3) Next, the calculation unit 43 selects the combination having the highest combustion efficiency of the boiler group 2 from the list stored in the memory 42. Here, W21 is selected.
4) Next, the calculation unit 43 shifts the second boiler 22 from the low combustion state to the high combustion state and shifts the third boiler 23 and the fourth boiler 24 in order to shift the boiler group 2 to the combustion state related to W21. Is output to each boiler via the output unit 46.
5) As a result, the combustion state of the boiler group 2 is changed as shown in FIG. Further, the total evaporation E after the change is 3600 (kg / h) which is the same as before the change of the combustion state.

  According to the boiler system 1, when the second combustion position that is the uppermost combustion position has higher combustion efficiency than the first combustion position that is the lowermost combustion position, the boiler at the first combustion position is subjected to the second combustion. The combustion efficiency of the boiler group 2 is improved while maintaining the total evaporation amount E of the boiler group 2 by shifting to the position and setting the high combustion state, and setting the boiler in the low combustion state to the combustion stop state as necessary. be able to.

Next, a second embodiment of the present invention will be described.
The boiler system 1A according to the second embodiment is different from the boiler system 1 in that the boiler group 2A according to the boiler system 1A includes three steam boilers, and the first boiler 26, the second boiler 27, and the third boiler. 28, each boiler 26, 27, 28 is a combustion stop state (combustion stop position), a first combustion position corresponding to a low combustion state (lowest combustion position), a second combustion position corresponding to a medium combustion state, respectively. (Medium combustion position), which is a four-position boiler that can be controlled to four stages of combustion states at a third combustion position (uppermost combustion position) corresponding to a high combustion state.

Moreover, in 2nd Embodiment, the evaporation amount when each boiler 26,27,28 is combusting in a 3rd combustion position is the rated evaporation amount of each boiler 26,27,28.
The difference evaporation amount J (i, j) and the combined evaporation amount G (i, j) at each combustion position of each boiler 26, 27, 28 in the second embodiment are as follows, and each combustion position: The combustion efficiency η (= η (i, j)) at is as shown in FIG.
<Differential evaporation amount and rated evaporation amount at each combustion position of boilers constituting boiler group 2A>
J (i, 1) J (i, 2) J (i, 3) G (i, 3)
1st boiler 26 1000 1000 1000 3000
Second boiler 27 1000 1500 1500 4000
Third boiler 28 500 1500 2000 4000
Each of the boilers 26, 27, and 28 is set such that the combustion efficiency related to the second combustion position is higher than the combustion efficiency in the low combustion state and the high combustion state.
Since others are the same as those in the first embodiment, the same reference numerals as those in the first embodiment are given and description thereof is omitted.

Next, the operation of the boiler system 1A according to the second embodiment will be described.
As in the first embodiment, for convenience, the total evaporation amount range E (R) of the boiler group 2A is set so that the total evaporation amount E is only 4500 (kg / h). Shall.
1) First, as shown in FIG. 8A, the boiler group 2A before the combustion state is changed, the first boiler 26 burns in the high combustion state, and the second boiler 27 and the third boiler 28 burn in the low combustion state. Assume that the total evaporation amount E is 4500 (kg / h), and the pressure in the steam header 6 is maintained in the pressure range P (R) for a predetermined time TS in this state. As a result, the calculation unit 43 executes the combustion state changing means of the program.
2) The calculation unit 43 refers to the second database 45B, and sets the total evaporation amount E of the boiler group 2A to 4500 (kg / h) as “combined boiler and combustion position for combustion in the boiler group 2A”. A list is created, and the combustion efficiency of the boiler group 2A in the combination is temporarily stored in the memory 42 in association with the list combination.
In this boiler group 2A, the combination in which the total evaporation E is 4500 (kg / h) includes W31 in the current combustion state,
W31 = J (1,1) + J (1,2) + J (1,3) + J (2,1) + J (3,1)
W32 = J (1,1) + J (1,2) + J (2,1) + J (2,2)
W33 = J (2,1) + J (2,2) + J (2,3) + J (3,1)
W34 = J (2,1) + J (2,2) + J (3,1) + J (3,2)
There are four ways.
When the combustion efficiency η31, η32, η33, η34 in the case of W31, W32, W33, W34 is calculated with reference to the data table (FIG. 7) of the second database 45B, η31 = 89.29%, η32 = 92 0.71%, η33 = 89.23%, and η34 = 91.00%.
3) Next, the calculation unit 43 selects the combination of the middle combustion states with the highest combustion efficiency of the boiler group 2A from the list stored in the memory 42. Here, W32 is selected.
4) Next, the calculation unit 43 shifts the first boiler 26 from the high combustion state to the middle combustion state and shifts the second boiler 27 from the low combustion state in order to shift the boiler group 2A to the combustion state related to W32. A control signal for shifting the third boiler 28 from the low combustion state to the combustion stop state in the middle combustion state is output to the boilers 26, 27, 28 via the output unit 46.
5) As a result, the combustion state of the boiler group 2A is changed as shown in FIG. Further, the changed total evaporation amount E is 4500 (kg / h) which is the same as before the change of the combustion state.

  According to the boiler system 1A, the combustion efficiency at the second combustion position, which is the middle combustion position of each boiler, is higher than the combustion efficiency at the third combustion position, which is the highest combustion position, and the first combustion position, which is the lowest combustion position. Is high efficiency, a part or all of the first combustion position and the third combustion position are shifted to the second combustion position to be in the middle combustion state, so the boiler is maintained while maintaining the total evaporation E of the boiler group 2A. The combustion efficiency of group 2A can be improved.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.
For example, in the above embodiment, the case has been described in which the steady state detection means determines whether the evaporation amount is in the steady state using the steam pressure P in the steam header 6 as the physical amount corresponding to the evaporation amount. Instead of the pressure P, the steady state may be determined using other physical quantities corresponding to the evaporation amount, such as the evaporation amount, the amount of steam used in the steam using facility 18, and the like.

  Moreover, in the said embodiment, the 2nd database 45B is the difference evaporation amount of each combustion position of each boiler 21, ..., 25 of the boiler group 2, or each boiler 26,27,28 of the boiler group 2A. J (i, j) and combustion efficiency η (i, j) are stored, and a list of combinations of boilers and their combustion positions that satisfy the total evaporation range E (R) is created from this data table 45B. Although it was set as the structure which selects the combustion state of the boiler groups 2 and 2A to transfer from the efficiency (eta) calculated in that case, you may use the database of another structure. For example, instead of the second database 45B, a combination of all the boilers and combustion positions in the boiler groups 2 and 2A, and a data table relating to the total evaporation amount E and combustion efficiency in the combination are calculated and stored in advance. Alternatively, a combination satisfying the total evaporation amount E may be selected, and a combination for controlling combustion based on the combustion efficiency may be selected.

  Moreover, in the said embodiment, the boiler group 2 which comprises the boiler system 1 is comprised by the five three position boilers, and the boiler group 2A which concerns on the boiler system 1A is comprised by the three four position boilers However, it is possible to configure the boiler groups 2 and 2A with any number of boilers of two or more, for example, a five-position boiler, a six-position boiler, or a boiler having a combustion position higher than these. Also good.

Further, in a boiler having a number of combustion positions equal to or greater than five position boilers, a plurality of middle combustion positions are set, and any one of these middle combustion positions is the highest combustion position and the lowest combustion position. It goes without saying that either or both of the positions may be superior in terms of combustion efficiency, followability, and the like.
In addition, one of a plurality of combustion positions in the middle combustion position is most dominant in terms of combustion efficiency, followability, etc., and another combustion position is set next dominant, The transition of the combustion position for changing the combination of the combustion positions may be performed within the range of the middle combustion position.

The boilers constituting the boiler group have a plurality of middle combustion positions between the highest combustion position and the lowest combustion position, and the combustion efficiency at the middle combustion position is the highest combustion position and the lowest combustion position. When the efficiency is higher than the combustion position, it is configured to shift from one of the plurality of intermediate combustion positions to another intermediate combustion position where the combustion efficiency is high. May be.
In this case, for example, there may be one intermediate combustion position or a plurality of intermediate combustion positions having higher combustion efficiency than the uppermost combustion position and the lowermost combustion position.

  In addition, when there are a plurality of middle combustion positions where the combustion efficiency is higher than that of the highest combustion position and the lowest combustion position, the middle combustion position that is the transition destination is not necessarily the highest efficiency in the boiler. The combustion position may not be required, the combustion efficiency may be the second or later middle combustion position, and the combustion efficiency at the middle combustion position where the combustion was performed before the transition is the highest combustion position or the highest combustion position. It may be less than the combustion efficiency of the lower combustion position. Further, the shift when the combustion position shifts may be either a shift to a higher level or a shift to a lower level.

  Some of the five boilers 21,..., 25 constituting the boiler group 2 or the three boilers 26, 27, 28 constituting the boiler group 2 A are planned and stopped due to, for example, failure or repair. Combustion control may be performed on a part of boilers that can be operated when the engine is in operation.

  Moreover, in the said embodiment, although the case where the number of combustion positions of the boiler which comprises the boiler groups 2 and 2A was demonstrated was demonstrated, the number of combustion positions about some or all of the boilers which comprise the boiler groups 2 and 2A It is good also as a different structure.

  Moreover, in the said embodiment, each boiler 21, ..., 25 of the boiler group 2 and each boiler 26,27,28 of the boiler group 2A are made into the same combustion position number, respectively, and the boiler group 2, the boiler group The case where 2A has at least one boiler whose turndown ratio is other than 1.0 by having combustion positions with different differential evaporation amounts has been described. However, the boiler group has a rated evaporation amount and a maximum combustion amount. It is sufficient that at least one of the turndown ratio and the number of combustion positions is provided, and the present invention can be applied to a boiler group including at least one boiler having a turndown ratio other than 1.0. .

Also, for example, any boiler whose combustion efficiency at the lowest combustion position is higher than the combustion efficiency at the highest combustion position is transferred from the highest combustion position to the lowest combustion position and another combustion stop position. When the boiler located at the lowermost combustion position is transferred to the lowest combustion position, the range of the combustion stop position may include a steaming transition process. In such a case, it is preferable to preferentially select the boilers in the steaming transition process. This is suitable for improving the following ability.
In addition, any boiler whose combustion efficiency at the highest combustion position is higher than the combustion efficiency at the lowest combustion position is transferred from the lowest combustion position to the highest combustion position and moved to another lowest combustion position. When a certain boiler is transferred to the combustion stop position, the followability of the boiler group may be improved by making the steaming transfer process the subject of the combustion stop position.
Here, the steaming transition process refers to a state between the combustion stop position and the first combustion position until steaming, and is classified into the following first state to fifth state.
First state: in low combustion position, not steaming but holding pressure Second state: after releasing low combustion, it becomes purge or pilot combustion state, not steaming but holding pressure State 3rd state: Low combustion is released and standby state is entered, steam is not supplied but pressure is maintained 4th state: Water is heated from the combustion stop position to the low combustion position, but pressure is increased State not holding (no pressure state)
Fifth state: purge or pilot combustion state but no pressure (no pressure state)
The fifth state includes a case where the pressure is reduced from the second state to a no-pressure state, and a case where the purge or pilot combustion state is entered at the combustion stop position and the pressure is not applied.
Further, in order to improve the followability by shortening the transition time, the first state, the second state, and the third state in the pressure holding state are preferable, but the state that is targeted when shifting to the combustion stop position Can be arbitrarily set from the first state, the second state, the third state, the fourth state, and the fifth state.
Further, regarding the fifth state of the steaming transition process, when the continuous pilot combustion state is a non-pressure state, when the pressure is reduced from the second state together with the continuous pilot combustion state to the no-pressure state, You may set arbitrarily from the case where it becomes a purge or a pilot combustion state, and is a no-pressure state.

The continuous pilot combustion state refers to the continuous combustion state of the pilot burner that is performed in order to prevent unburned gas from staying in the can so that it can be ignited as soon as a combustion signal is output in a gas-fired boiler. Say.
Note that the light air purge is a small air flow rate by reducing the blower rotation speed so that unburned gas does not stay in the can so that it can be ignited as soon as a combustion signal is output in an oil-fired boiler. This means maintaining the air blowing state.

  In the above embodiment, the case where the program has the steady state detection means and the combustion state change means and is based on the flowchart illustrated in FIG. 3 has been described. However, the program is based on a flowchart different from this flowchart. Of course, the program may be configured.

Further, when the combustion state of the boiler groups 2 and 2A is changed, the total evaporation that is determined to be in the steady state when there are a plurality of combinations of boilers and combustion positions that satisfy the evaporation amount range E (R). If the physical quantity corresponding to the amount E or the total evaporation amount E such as pressure exceeds a set value (for example, a target value), the total evaporation amount E is reduced, and if it is below, the total evaporation amount E is increased. Thus, the combination of the boiler to be burned and its combustion position may be changed.
As a result, the difference between the required evaporation amount and the total evaporation amount E of the boiler group can be reduced.

  Moreover, in the said embodiment, although the case where the priority order was not set regarding the boiler which comprises the boiler groups 2 and 2A was demonstrated, a priority order is set with respect to all or one part of a boiler, for example. Alternatively, the boilers to be burned in the boiler groups 2 and 2A and the combustion positions thereof may be selected based on the priority order or both of the priority order and the superiority of the combination.

  In addition, for example, in the case where priority is set for each boiler in a boiler group in which boilers with high efficiency in the low combustion state and boilers with high efficiency in the high combustion state are mixed, the combustion efficiency (or responsiveness) of each boiler is set. It is good also as a structure which burns each boiler in a combustion position where each is considered in consideration.

  For example, among the boilers in any one of the combustion positions, the transition time may be automatically set by automatically learning the necessary time (time lag etc.) when the predetermined ratio shifts to the target combustion position. Good.

  In the above-described embodiment, the case where the control according to the present invention is performed by a program has been described. However, it is natural that the control may be performed by analog control using an operational amplifier or the like regardless of the program.

  In the above embodiment, the case where the storage medium for storing the program is the ROM has been described. However, in addition to the ROM, for example, EP-ROM, hard disk, flexible disk, optical disk, magneto-optical disk, CD A ROM, CD-R, magnetic tape, nonvolatile memory card, or the like may be used. Further, not only the operation of the above-described embodiment is realized by executing the program read out by the arithmetic unit, but an OS (operating system) operating in the arithmetic unit based on an instruction of the program performs actual processing. This includes a case where the operation of the above embodiment is realized by performing part or all of the above. Furthermore, after the program read from the storage medium is written to the memory provided in the function expansion board inserted in the operation unit or the function expansion unit connected to the operation unit, the function expansion is performed based on the instructions of the program. It goes without saying that the case where the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing and the operation of the above-described embodiment is realized by the processing.

  When the combustion state is changed in the boiler group, stable steam supply can be performed, so that it can be used industrially.

1, 1A boiler system 2, 2A boiler group 21, 22, 23, 24, 25, 26, 27, 28

Claims (11)

Equipped with a plurality of boilers that increase or decrease the combustion amount step by step, the difference evaporation amount that increases or decreases when one of the combustion positions of at least one boiler is shifted to one step, one of the combustion positions of the other boilers It is a program for controlling a boiler group configured differently from the difference evaporation amount that increases or decreases when transitioned,
When the total evaporation amount totaling the evaporation amount of the boilers in combustion in the boiler group or the physical amount corresponding to the total evaporation amount is maintained for a predetermined time,
A program configured to change a combination of a boiler to be burned in the boiler group and its combustion position while maintaining the total evaporation amount within a predetermined range. A plurality of boilers that increase or decrease the combustion amount in stages, and at least one boiler is different from other boilers in terms of at least one of maximum combustion amount, turndown ratio (maximum combustion amount / minimum combustion amount), and number of combustion positions. A program for controlling boiler groups having different configurations,
When the total evaporation amount totaling the evaporation amount of the boilers in combustion in the boiler group or the physical amount corresponding to the total evaporation amount is maintained for a predetermined time,
A program configured to change a combination of a boiler to be burned in the boiler group and its combustion position while maintaining the total evaporation amount within a predetermined range. A program for controlling the boiler group according to claim 1 or 2,
A program for controlling a boiler group, characterized in that a combination of boilers and their combustion positions in the boiler group is configured to shift to a pre-set advantageous combination. The program according to claim 3,
When the boiler constituting any one of the boiler groups has higher efficiency of combustion at the lowest combustion position than combustion at the highest combustion position,
A program configured to transfer any one of the boilers at the highest combustion position to the lowest combustion position and to transfer another stopped boiler to the lowest combustion position. The program according to claim 3,
When the boiler constituting any one of the boiler groups has higher efficiency of combustion at the uppermost combustion position than combustion at the lowermost combustion position,
A program configured to shift one of the boilers at the lowest combustion position to the highest combustion position and stop another boiler at the lowest combustion position. The program according to claim 3,
When the boiler constituting any one of the boiler groups is more efficient than the uppermost combustion position and the lowermost combustion position in the middle combustion position between the uppermost combustion position and the lowermost combustion position,
When at least one of the boiler at the uppermost combustion position and the boiler at the lowermost combustion position exists, either one of these boilers is more efficient than the uppermost combustion position and the lowermost combustion position. The program is configured to shift to the middle combustion position. The program according to claim 3,
The boiler constituting any one of the boiler groups has a plurality of middle combustion positions between the highest combustion position and the lowest combustion position, and the combustion efficiency at any of the middle combustion positions is the highest combustion. If the position and the lowest combustion position are more efficient,
A program configured to shift from any one of the plurality of intermediate combustion positions to another intermediate combustion position where the combustion efficiency is high. A program according to any one of claims 1 to 7,
Priorities are set for the boilers to be burned in the boiler group and their combustion positions;
A program configured to change a combination of a boiler to be burned in the boiler group and a combustion position based on the priority order. A program according to any one of claims 1 to 8,
When there are a plurality of combinations of boilers and their combustion positions in the boiler group within the predetermined range,
When the total evaporation amount or a physical amount corresponding to the total evaporation amount is maintained above a set value, the boilers that are burned in the boiler group so that the total evaporation amount is reduced within the predetermined range; Change the combination of the combustion positions,
When the total evaporation amount or a physical amount corresponding to the total evaporation amount is maintained below a set value, the boilers that are burned in the boiler group so that the total evaporation amount is increased within the predetermined range; and A program configured to change the combination of the combustion positions.   A controller comprising the program according to any one of claims 1 to 9.   A boiler system comprising the controller according to claim 10.

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