JPH0251702A - Optimization controller - Google Patents

Abstract

PURPOSE:To reduce the load of an operator and the output loss and to ensure the effective operation of a plant by calculating the target value in response to the load information on the plant and changing automatically the calculated target value. CONSTITUTION:A plant load detecting part 3 detects the load state of a plant 1 and the plant load information (a) on an operation crank, etc., which is presently measured or set. Then a target value calculating part 4 calculates automatically the target value (d) of the plant operating state in response to the plant load state. In case the value (d) is different from the target value (e) stored in a target value memory part 5, the newly calculated value (d) is set at the part 5. Hereafter the plant 1 is controlled based on the value (d).

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to an optimization control device that maintains the operating state of a plant in an optimal state, and in particular constantly detects plant load information and The present invention relates to an optimization control device that variably sets target values for plant operating conditions in response to information.

(Prior art) As one of the control devices that control the operating status of a plant,
There is an optimization control device that automatically calculates set values of various manipulated variables for a plant and applies them to the relevant plant so that the plant operating state is maintained at a target value that is preset in a storage unit, for example.

The basic operation of this optimization control device will be explained by applying it to a boiler plant, for example. That is, in controlling the boiler, the target value of the required amount of steam is assumed as the target value of the operating state of the plant. Then, by setting this target value, the amount of fuel F4 and the amount of air to be input are determined so that the actual amount of steam generated becomes the target value, and the boiler is driven with this amount of fuel and air. That is, the determined fuel amount and air amount become the set values for the plant. The target value of the required amount of steam is manually input by an operator using a gearboard or the like of an input terminal.

However, as described above, the optimization control device in which the operator manually sets the target value of the operating state of the plant has the following problems that still need to be solved.

That is, depending on the plant, the above-mentioned target value may differ depending on the load state of the plant and the operational rank of the plant. For example, considering the amount of steam in the boiler mentioned above, when this steam is used for heating factories or offices or for power generation, it depends on the time of the day, the day of the week, and the season of the year. The amount of steam required varies. In such cases, if you set the required amount of steam, that is, the target value, to the amount of steam at the peak time, a large amount of steam may remain unused depending on the time of day, and
It will be a loss. Furthermore, the plant is constantly operated under a high load, and each component of the plant is subject to severe wear and tear, resulting in a shortened lifespan of the plant as a whole. Conversely, if the target value is set to a low value of the required steam amount, the steam amount will naturally be insufficient at peak times.

In this way, when the target value of the operating state required of the plant changes depending on the load situation, in order to perform optimal operation of the plant, the operator must manually adjust the target value itself. It is necessary to always change the optimum target value. Therefore, in plants where the target value is changed frequently, or in plants where the target value cannot be changed significantly at once and must be changed in stages, the operation of changing the target value becomes extremely troublesome for the operator. Moreover, in cases where changes need to be made frequently and in a short period of time, this cannot be dealt with as a practical problem.

Therefore, in such a case, since the plant is operated by setting an appropriate target value, it is not possible to maintain a plant operating state corresponding to the required load, resulting in a problem that the plant cannot be operated efficiently.

(Problem to be solved by the invention) As described above, in conventional optimization control devices, the operator manually sets the target value of the plant operating status each time, which increases the burden on the operator. In addition, if the setting values are changed frequently, problems that cannot be solved by manual operation will arise.

The present invention constantly monitors plant load information, calculates a target value corresponding to the load information, and automatically changes the target value, thereby reducing the burden on the operator and reducing output loss. The purpose of this invention is to provide an optimization control device that can efficiently operate a plant.

[Structure of the Invention] (Means for Solving Three Problems) In order to solve the above problems, the present invention includes a target value storage unit that stores target values of plant operating conditions, and a target value storage unit that stores target values of plant operating conditions. It has an optimization calculation unit that calculates set values of various manipulated variables corresponding to target values, and a set value output unit that outputs the set values of various operations m calculated by this optimization calculation unit to the plant. The optimization control device includes a plant load information detection section that detects the plant load state or the currently set plant load, and a plant operation corresponding to the load information based on the plant load information detected by the plant load information detection section. A target value calculation unit that calculates a target value of a state, and when the target value calculated by this target value calculation unit and the target value stored in the target value storage unit are different, the target value is stored in the target value storage unit. The target value setting section rewrites the target value to a newly calculated target value.

(Operation) In the present invention, by taking the above-mentioned means, currently measured or set plant load information such as the plant load state and operation rank is detected by the plant load information detection section. Then, the target value calculation unit automatically calculates a target value for the plant operating state corresponding to the plant load state. Then, the newly calculated target value is target ra, :C! If the target value is different from the target value stored in the storage section, the new target value is set in the target value storage section.

The plant is then controlled using this newly set target value.

In other words, the target value according to changes in the load status of the plant,
This is determined from the plant load information obtained from measured values detected from the plant, calculation results calculated from the measured values, operation ranks for each time period from internal or external sources, and instructions from the operator. Since the target values are updated, the best plant operating conditions can be maintained at all times.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an optimization control device according to an embodiment. That is, in this embodiment, the measured value a corresponding to the brand load output from the plant 1 as the controlled object is input, and the manual input value corresponding to the plant load is input from the input terminal 2 operated by the operator. A goal of calculating a target value d of the plant operating state using the plant load detection section 3 as the plant load information detection section inputted by the plant load detection section 3 and the plant load signal C as the plant load information outputted from the plant load detection section 3. A value calculation unit 4, a target value storage unit 5 that stores the target 1iie of the operating state of the plant l, and a target value that sets the target value d newly calculated by the target value calculation unit 4 in the target value storage unit 5. A setting unit 6, an optimization calculation unit 7 that calculates set values f of various control variables of the plant 1 using the target value e stored in the target value storage unit 5, and a and a set value output unit 8 that applies set values of various manipulated variables to the plant 1.

The input terminal 2 is composed of a CRT display section and a keyboard, and the target value storage section 5 is, for example, a RAM.
It is made up of memory elements such as.

In addition, other plant load detection units 3. Target value calculation unit 4
．． Target value setting section 6. Optimization calculation unit 7. The set value output section 8 and the like are realized by the program procedure of the control program.

Next, the specific operation of each part will be explained. The plant load detection unit 3 receives seven measured values a regarding the plant load from the plant 1.
is input, and data processing such as signal processing using a filter, calculation, etc. is performed on this measured value a as necessary. moreover,
The plant load detecting section 3 inputs the manual input value regarding the plant load outputted from the input terminal 2, and performs necessary data processing in the same manner as the measurement value a.

Then, the plant load detection unit 3 receives the input measurement value 8
1. A plant load signal C is created using one or both of the manual input values. This plant load signal C
For example, each measurement value x, -Xn input from plant 1
and each manual input value H1~ entered manually from the input terminal 2
H is multiplied by a weighting coefficient al-afL+N, respectively, and expressed by a linear combination polynomial as shown in equation (1).

Plant load signal C"a+X+ + a2X2+・=・
・' + aaXa + afi++Ii++ am+
J2” ・・・・・・” a*+JIa=
・(1) The method for creating the plant load signal C is as described above (
The method is not limited to the method shown in equation 1), and can be changed to an optimal value as appropriate depending on the type of the n1 constant value a or the manual input value.

The plant load signal C output from the plant load detection section 3 is input to the target value calculation section 4. The target value calculation unit 4 uses the input plant load signal C to calculate a target value d corresponding to the load. As shown in FIG. 2, the target value calculation unit 4 stores in advance a conversion pattern diagram showing the relationship between each plant load signal C and each target value d corresponding to each plant load signal C value. When the plant load signal C is input, a target value d corresponding to the corresponding plant load signal C value is calculated from this conversion pattern diagram. The target value d thus calculated is sent to the next target value setting section 6.

The target value setting unit 6 reads the target value e already stored in the target value storage unit 5 and compares it with the input target value d. Then, both target values d within a certain tolerance range.

If e matches, there is no need to change the target value, so the target value e in the target value storage section 5 is not changed. If they do not match, it is necessary to rewrite the target value e in the target value storage section 5.

When the need for rewriting arises, the target value setting unit 6 first checks the calculation state of the optimization calculation unit 7. When the calculation status signal g is input from the optimization calculation unit 7 and the calculation status signal g indicates that the calculation is in progress, a calculation stop request signal is sent to the optimization calculation unit 7, and the optimization is started. The arithmetic operation of the arithmetic unit 7 is stopped. This is because if the target value e is changed during the optimization calculation process, the setting value f of each manipulated variable calculated using the target value e before the change has no meaning.

When the UJ target value setting unit 6 confirms that the optimization calculation unit 7 has canceled the optimization an operation for determining the setting @f using the input calculation status signal g, the UJ target value setting unit 6 sends the newly calculated value to the target value setting unit 5. The target value d is sent and the target value e stored in the target value storage section 5 is rewritten to a new target value d. When the rewriting is completed, the target value setting unit 6 sends an optimization calculation start signal i to the optimization calculation unit 7.

The optimization calculation unit 7 that received the optimization calculation start signal i retrieves the target value e from the target value storage unit 5 which has been rewritten to the new target value d.
is read out, and setting values f of various manipulated variables of the plant 1 are calculated using this target value e.

Then, it is sent to the set value output section 8.

The set value output unit 8 applies the processed set value f to the plant 1 while checking the upper and lower limits and performing PID control on the input set value f as necessary.

In the plant 1 where the set value f of each control variable is manually input from the set value output unit 8, the plant operating state changes according to the input set value f. Finally, the deviation between the plant operating state and the target value e set in the target value setting section 5 becomes minimum.

With the optimization control device configured in this way, when the load of the plant 1 changes, the plant load detection section 3 detects the load state of the plant 1, and the target value calculation section 4 automatically adjusts the plant load state. A target value d corresponding to is calculated. Then, the new target value d is written into the target value storage section 5. Therefore, the setting fM corresponding to this new target value d
f is calculated and applied to plant 1. Then, the plant 1 enters an operating state corresponding to the load state.

In addition, if the dPj fixed value a from the plant 1 is not the manual input value indicating the plant load from the input terminal device 2, or if the measured value a from the plant 1 and the input terminal device 2
Even if the manual input values d and d are entered at the same time, the eyesight value d is automatically calculated as described above
A set value f corresponding to the target 1i1d is applied to the plant 1. Then, the deviation between the operating state of the plant 1 and the new target value becomes minimum.

Therefore, it is possible to significantly reduce the operator's effort when changing one standard value.

FIG. 3 is a block diagram showing an optimization control device according to another embodiment of the present invention. Components that are the same as those in FIG. 1 are designated by the same reference numerals, and explanations of overlapping portions will be omitted.

In this embodiment, the timer 10
The target value d is calculated using the time information j from and the time zone data k from the time data setting section 11.

That is, the timer 10 inputs the current time information j, which changes from time to time, such as year, month, day, day of the week, one hour, etc., to the operation rank detection section 12 as a plant load information detection section. Furthermore, this driving rank detection section 12 includes a time data setting section 1.
Preset time zone data k from 1 is input. Furthermore, the values of the operating ranks of the plant 1 in each time period are input manually from the input terminal 2 operated by the operator.

The driving rank detection unit 12 refers to the time zone data input from the time data setting unit 11 and the driving ranks for each time zone input from the input terminal 2, and determines the time information j input from the timer 11. The operating rank at the current time shown is sent to the target value calculation unit 4 as an operating rank signal m corresponding to the plant load information.

The relationship between each time zone data and the driving rank I is set, for example, as shown in the table below.

Note that the XX symbol in the table indicates an arbitrary value, and each time zone data k has times that overlap with each other, but in this case,
Priority is given to year, month, and day, followed by day of the week and time. For example, in the above example, the driving rank is 3 from 1:00 to 5:00 on January 1, regardless of the day of the week. Further, on Sunday, the driving rank is 2 regardless of other conditions, but on January 1st, the year, month, and day take priority, so the driving rank is 3 during the time period from 1:00 to 5:00.

Therefore, when time information j indicating the current time is inputted from the timer 10, the driving rank corresponding to the current time is retrieved from the clothing and sent to the target value calculation unit 4 as the driving rank signal m.

In the storage section of the target value calculation section 4, as shown in FIG.
A target value table is formed that stores each target value corresponding to each driving rank. When the driving rank signal m is input from the driving rank detecting part 12, the target value calculating section 4 calculates a target value d corresponding to the driving rank indicated by the driving rank signal m using a target value table. and,
The calculated target value d is sent to the next target value setting section 6.

The target value setting section 6 stores the input target value d and the target value storage section 5.
If they do not match, the target value e stored in the target value storage section 5 is rewritten to a new target value d. Then, the optimization setting unit 7 calculates a set value f using this new target value, and applies it to the plant 1 via the set value output unit 8.

In the optimization control device configured in this way, the time data setting section 11 and the input terminal 2 input each operation rank to the operation rank detection section 12 for each time period to the operation rank detection section 12 for each time period. The settings are made in advance prior to the operation of step 1. Then, after the plant 1 is started, the operation rank changes sequentially by 1f as the time elapses based on the time information j indicating the current time from the timer 10, and a new target is set in response to the change in the operation rank. The value is automatically calculated, and a set value f corresponding to the calculated target value is applied to the plant 1. Thus, the operating state of the plant 1 follows the target value in conjunction with the change in the target value.

In this way, by setting the target value in a program in advance, the operator can control the operating state in response to changes in the load state of the plant, without having to change the equivalent target value during operation.

As a result, operational losses caused by setting an unnecessarily high target value can be minimized. In addition, it is possible to prevent plant maintenance and durability from being shortened due to constant high-load operation.

In the above description, each operation rank is set in advance for each time period prior to the operation of the plant 1, but the operation rank can also be changed while the plant 1 is in operation.

[Effects of the Invention] As explained above, according to the optimization control device of the present invention,
Plant load information such as plant load and operation rank is constantly monitored, a target value corresponding to the load information is calculated, and the target value is automatically changed to optimally control the plant. Therefore, since the target value is automatically updated, it is possible to respond to small changes without increasing the burden on the operator.
It becomes possible to expand the applicable control range. Furthermore, since output loss can be reduced, the plant can be operated efficiently.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an optimization control device according to an embodiment of the present invention, FIG. 2 is a diagram showing the relationship between a plant load signal and a target value in the same embodiment, and FIG. 3 is a block diagram showing an optimization control device according to an embodiment of the present invention. Optimization control related to embodiments 1...Plant, 2...
Input terminal device, 3... Plant load detection section, 4... Target value calculation section, 5... Target value storage section, 6... Target value setting section, 7... Optimization calculation section, 8 ...Set value output section,
10...Timer, 11...Time data setting section, 12
...Driving rank detection section.

Claims (1)

[Claims] a target value storage unit that stores target values of plant operating conditions;
An optimization calculation unit that calculates set values of various manipulated variables corresponding to the target values stored in this target value storage unit, and a set value of various manipulated variables calculated by this optimization calculation unit to the plant. an optimization control device having a set value output section that outputs a set value, a plant load information detection section that detects the load state of the plant or the currently set plant load; and a plant load detected by the plant load information detection section. A target value calculation unit that calculates a target value of a plant operating state corresponding to the load information from the information, and a target value calculated by the target value calculation unit and a target value stored in the target value storage unit. An optimization control device comprising: a target value setting unit that rewrites the target value stored in the target value storage unit to a newly calculated target value when the target value is different.