JP5855964B2 - Optimal control method and optimal control device for plant equipment - Google Patents

Description

  The present invention relates to an optimum control method and an optimum control device for plant equipment that optimally controls the operating state of plant equipment such as water treatment equipment.

  In general, in water treatment facilities that perform sewage treatment (sewage), water purification (water supply), industrial industrial water and wastewater treatment, etc., the optimum operation state of the water treatment facility is obtained by optimization calculation. An operation command procedure for equipment and devices for realizing an operation state is generated, and the equipment and devices are operated in accordance with the generated operation command procedure (see, for example, Patent Document 1).

JP 2010-231457 A

  In the conventional optimum control method, the fixed equipment is mainly determined and controlled for the optimum operating state of the water treatment equipment that operates based on a certain rule, so that it is suitable for the target water treatment equipment. Water treatment facilities are controlled using one optimal control model using two optimization methods. However, since the actual state of the water treatment facility changes from moment to moment, the conventional optimum control method using one fixed optimum control model has the accuracy of the optimum control according to the timing of executing the optimum control. It is difficult to control the water treatment equipment with high precision and accuracy. For this reason, it has been expected to provide a technique capable of accurately and optimally controlling the water treatment facility regardless of the timing of executing the optimal control.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an optimal control method and an optimal control device for plant equipment capable of accurately controlling the plant equipment with high accuracy regardless of the timing for executing the optimal control. It is to provide.

In order to solve the above-mentioned problems and achieve the object, the optimal control method for plant equipment according to the present invention is data relating to the amount of power demand and supply capacity in plant equipment adjusted based on the supply and demand prediction of power in plant equipment. A calculation step for calculating a power supply reserve capacity, an operating cost, an operating efficiency, and a CO ₂ emission amount with respect to a target value of the plant equipment, and data on the operation status of the plant equipment at the execution timing of the optimization process ; comparing the data relating to supply and demand planning of the plant equipment in the execution timing of the optimization process of the immediately preceding, when the difference is equal to or greater than a predetermined value, the evaluation function including the difference as a variable, constituting the evaluation function a correction step of correcting the adjustment variables, model optimization of the optimal solutions plant equipment of the corrected evaluation function And optimization step of calculating as, characterized in that it comprises a control step of controlling the operation of the plant equipment in accordance with the optimization model.

  The optimum control method for plant equipment according to the present invention is characterized in that, in the above invention, the method includes a step of displaying information relating to the operation status of past and current plant equipment and information relating to an operation plan of the plant equipment.

In order to solve the above-mentioned problems and achieve the object, the optimum control device for plant equipment according to the present invention is a data relating to the demand and supply capacity of power in the plant equipment adjusted based on the supply and demand prediction of power in the plant equipment. using the power supply reserve of plant equipment, operating costs, operating efficiency, and a calculating means for calculating a deviation from the target value of the CO ₂ emissions, the data related to the operation status of the plant equipment in the execution timing of the optimization process comparing the data relating to supply and demand planning of the plant equipment in the execution timing of the optimization process of the immediately preceding and, if the difference is greater than a predetermined value, the evaluation function including the difference as a variable, constituting the evaluation function and correction means for correcting the adjustment of the variable to the optimal solution of the corrected evaluation function as an optimization model of the plant equipment And optimization means for output, characterized in that it comprises a control means for controlling the operation of the plant equipment in accordance with the optimization model.

  According to the optimal control method and the optimal control device for plant equipment according to the present invention, the plant equipment can be optimally controlled with high accuracy regardless of the timing for executing the optimal control.

FIG. 1 is a schematic diagram illustrating a configuration example of a sewage treatment plant to which an optimum control system according to an embodiment of the present invention is applied. FIG. 2 is a block diagram showing a configuration of an optimal control system according to an embodiment of the present invention. FIG. 3 is a flowchart showing the flow of optimal control processing according to an embodiment of the present invention. FIG. 4 is a conceptual diagram for explaining the processing in step S1 shown in FIG.

  Hereinafter, an optimal control system for a sewage treatment plant according to an embodiment of the present invention will be described with reference to the drawings. In addition, although this embodiment applies this invention to the optimal control of a sewage treatment plant, this invention is not limited to this embodiment, Sewage treatment (sewer), purified water treatment (waterworks) It can also be applied to optimal control of plant facilities other than sewage treatment plants such as water treatment facilities for industrial industrial water / wastewater treatment.

[Configuration of sewage treatment plant]
First, the configuration of a sewage treatment plant to which an optimum control system according to an embodiment of the present invention is applied will be described with reference to FIG. However, the configuration of the sewage treatment plant is not limited to the configuration shown in FIG.

  FIG. 1 is a schematic diagram illustrating a configuration example of a sewage treatment plant to which an optimum control system according to an embodiment of the present invention is applied. As shown in FIG. 1, a sewage treatment plant to which an optimum control system according to an embodiment of the present invention is applied includes a sewage treatment facility 1 for treating sewage and sludge for treating excess sludge generated in the sewage treatment facility 1. And a processing facility 2.

  The sewage treatment facility 1 includes a sand basin 11, a first sedimentation basin 12, a reaction tank 13, a final sedimentation basin 14, and a chemical injection tank 15. The sedimentation basin 11 is equipment for precipitating and removing non-septic inorganic substances such as earth and sand in sewage, and the sewage from which the non-septic inorganic substances have been removed is supplied to the first sedimentation basin 12 by a sewage pump 16. The first settling basin 12 is a facility for removing sedimentary organic substances in the sewage by sedimentation by gently flowing the sewage. First, the supernatant water of the sedimentation tank 12 is supplied to the reaction tank 13. The sediment in the initial sedimentation basin 12 is collected by the sludge scraper 17a and supplied to the sludge treatment facility 2 as excess sludge by the sludge extraction pump 18.

  The reaction tank 13 controls the amount of air supplied from the blower 19 to the reaction tank 13 according to indices such as DO (dissolved oxygen concentration), MLSS (active sludge concentration in the tank), sewage flow rate, ORP (oxidation reduction potential). This is a facility that uses microorganisms to treat pollutants, mainly organic matter, nitrogen and phosphorus in sewage. The amount of air supplied to the reaction tank 13 is detected using a pressure gauge 20. The sewage from which the pollutants are removed is supplied to the final sedimentation basin 14, and a part of the sediment in the reaction tank 13 is supplied to the sludge treatment facility 2 as excess sludge by the sludge extraction pump 18.

  The final sedimentation basin 14 is a facility that separates the sewage supplied from the reaction tank 13 into treated water and activated sludge. The treated water is supplied to the chemical injection tank 15. The activated sludge is collected by the sludge scraper 17b and returned to the reaction tank 13 or supplied to the sludge treatment facility 2 as excess sludge by the sludge extraction pump 18. The chemical injection tank 15 is a facility for disinfecting the treated water by injecting chemicals into the treated water supplied from the final sedimentation basin 14 using the chemical injection pump 21 and then discharging the disinfected treated water to a river or the like. It is.

  The sludge treatment facility 2 includes a concentration tank 31, a digestion tank 32, a dehydrator 33, and an incinerator 34. The concentration tank 31 is a facility that concentrates excess sludge by removing moisture in the excess sludge supplied from the sludge extraction pump 18. Excess sludge concentrated in the concentration tank 31 is collected by a sludge scraper (not shown) and supplied to the digestion tank 32.

  The digestion tank 32 is a facility for decomposing organic matter in excess sludge to obtain digested sludge. Digested sludge generated in the digestion tank 32 is supplied to a dehydrator 33. The dehydrator 33 is a facility that reduces the moisture content of the digested sludge by dehydrating the digested sludge supplied from the digestion tank 32. The incinerator 34 is a facility that incinerates digested sludge whose water content has been reduced by the dehydrator 33.

[Configuration of optimal control system]
Next, with reference to FIG. 2, the structure of the optimal control system which is one Embodiment of this invention is demonstrated.

  FIG. 2 is a block diagram showing a configuration of an optimal control system according to an embodiment of the present invention. As shown in FIG. 2, the optimal control system 100 according to an embodiment of the present invention includes a performance data database 101, a supply and demand plan database 102, an input device 103, an optimal control device 104, and an output device 105.

The performance data database 101 stores data of past power demand and demand and past power supply capacity and amount at the sewage treatment plant as operation result data. Supply plan database 102 stores data relating to supply and demand planning of power sewage treatment in a predetermined period that is created by using the operation result data stored in the actual data database 10 1. The input device 103 is configured by a known input device such as a keyboard and a mouse pointer, and is operated when various information is input to the optimum control device 104.

  The optimum control device 104 includes a workstation such as a personal computer and an information processing device such as a process computer. The optimal control device 104 functions as a supply and demand adjustment unit 104a, a supply and demand control unit 104b, and an evaluation function correction unit 104c when an arithmetic processing device such as a CPU in the information processing apparatus executes a computer program. The functions of these units will be described later. The output device 105 is for outputting various information from the optimum control device 104 to a control device, a display device, a printing device, and the like of the sewage treatment plant.

[Optimum control processing]
In the optimal control system 100 having such a configuration, the optimal control device 104 performs the optimal control processing shown below, thereby optimally controlling the sewage treatment plant shown in FIG. Hereinafter, with reference to the flowchart shown in FIG. 3, the operation of the optimum control device 104 when executing this optimum control process will be described.

  FIG. 3 is a flowchart showing the flow of optimal control processing according to an embodiment of the present invention. The flowchart shown in FIG. 3 is started every predetermined control cycle, and the optimum control process proceeds to the process of step S1.

  In the process of step S <b> 1, the supply and demand adjustment unit 104 a determines whether the power supply capacity is excessive or insufficient based on the power supply and demand plan data of the sewage treatment plant within a predetermined period stored in the supply and demand plan database 102. Specifically, first, as shown in FIG. 4, the supply and demand adjustment unit 104a has a positive factor for the power supply capacity (assumed supply capacity) assumed in the supply and demand plan, and the demand amount ( Assuming demand is a negative factor, the assumed value is synthesized. If the assumed value is positive, it is determined that the supply capacity is excessive, and if the estimated value is negative, it is determined that the supply capacity is insufficient. In this process, the supply and demand adjustment unit 104a may determine whether the power supply capacity is excessive or insufficient in consideration of whether or not reserve power corresponding to a predetermined percentage of the power demand remains in the power supply capacity. Thereby, the process of step S1 is completed and the optimal control process proceeds to the process of step S2.

In the process of step S2, the supply and demand adjustment portion 104a is in accordance with the determination result of the input device 103 preset are the input information and step S 1 from being supplied from the power generation equipment and power generation equipment is provided in the sewage treatment plant power The operation procedure of the load equipment that operates is determined. Power generation facilities include solar power generation facilities, solar thermal power generation facilities, wind power generation facilities, micro hydroelectric power generation facilities, gas engine power generation facilities, micro gas turbine power generation facilities, fuel cells, internal combustion engines, secondary batteries (discharges), power Examples include interchange / consignment (power reception) and commercial power reception facilities. Examples of the load equipment include the sewage pump 16, sludge scrapers 17a and 17b, the sludge extraction pump 18, the blower 19, the chemical injection pump 21, and the incinerator 34 shown in FIG.

  Specifically, when the power supply capacity is set to be prioritized over the power demand, and the power supply capacity is excessive, the supply and demand adjustment unit 104a charges the secondary battery included in the load facility. Increase the demand for power by increasing the operating capacity of the load equipment, and performing adjustment procedures such as consignment (power transmission) and power sales (surplus purchase). On the other hand, when the setting is made to give priority to the power supply capacity over the power demand and the power supply capacity is insufficient, the supply and demand adjustment unit 104a discharges the secondary battery included in the load facility. Demand for electric power is reduced by performing adjustment procedures such as reducing the operation amount of load equipment, consignment (power reception), and use of commercial power.

  Further, when the setting is made so that the power demand is prioritized over the power supply capacity, and the power supply capacity is excessive, the supply and demand adjustment unit 104a charges the secondary battery included in the load facility. The power supply capacity is reduced by performing adjustment procedures such as consignment (power transmission) and power sales (surplus purchase) that suppress the output of power. On the other hand, when the setting is made so that the power demand is prioritized over the power supply capacity, and the power supply capacity is insufficient, the supply and demand adjustment unit 104a discharges the secondary battery included in the load facility. The power supply capacity is increased by performing adjustment procedures such as enlarging the output of the power generation facility, consignment (power reception), and use of commercial power.

  Moreover, when the setting which gives priority to the balance between the power demand and the power supply capacity is made, and the power supply capacity is excessive, the supply and demand adjustment unit 104a suppresses the output of the power generation facility. ), Power supply capacity is reduced by adjusting procedures such as selling power (surplus purchase), etc., and power demand is increased by adjusting procedures such as charging the secondary battery of the load equipment and increasing the operating capacity of the load equipment. . In addition, when the setting for giving priority to the balance between the power demand and the power supply capacity is made and the power supply capacity is insufficient, the supply and demand adjustment unit 104a selects the secondary battery included in the load facility. The power supply capacity is increased by adjustment procedures such as discharging, increasing the output of the power generation equipment, consignment (power reception), and the use of commercial power, and the power demand is reduced by reducing the operation amount of the load equipment.

  In the present embodiment, the supply and demand adjustment unit 104a determines the content of the adjustment procedure in each case by calculating the optimum solution of the evaluation function H as shown in the following formula (1).

Here, in Equation (1), H _rpow is a deviation from the target value of power supply capacity (operational numerical target) after execution of the adjustment procedure, and H _cost is power generation cost (initial cost, running cost, fuel) after execution of the adjustment procedure. expenses, the target deviation from the target value of those considering all matters relating to the cost), H _effi the sewage treatment plant after the adjustment procedure execution efficiency (ratio of output / workload for the input / energy consumption) deviation for the values, H _{of co2} adjustment procedure CO ₂ emissions sewage treatment plant after the execution (emissions during manufacture of the equipment, etc., emissions due energy during operation, all related to the emissions in terms of CO ₂ This shows the deviation from the target value). In addition, PF indicates a punishment function, and operating conditions and restriction conditions (extracted from the condition setting table indicating the correspondence between the equipment and equipment and the operation conditions and restriction conditions) that constitute the sewage treatment plant. Represents. p, g, r, and s indicate weighting coefficients assigned to each deviation, and the sum of the weighting coefficients is set to 1. By making the weighting factor of the desired deviation larger than the other weighting factors, an optimization model in which the desired deviation is emphasized can be generated.

As is clear from Equation (1), the supply and demand adjustment unit 104a minimizes the sum of the deviations, in other words, the minimum solution (evaluation function H) so that the difference from the target value approaches zero. That is, by obtaining an optimal solution, the contents of the adjustment procedure (combination of operation of the equipment) are determined as an optimization model of the sewage treatment plant. As an example of the calculation method for obtaining the minimum solution (optimum solution) of the evaluation function H, a particle swarm optimization (PSO) method can be used. In addition, when the equipment is started and stopped based on the optimal control process, the operating state of the facilities constituting the sewage treatment plant may change suddenly at the turn of the season and the occurrence of abnormal weather (for example, guerrilla heavy rain). is there. For this reason, the supply and demand adjustment unit 104a compares the state of the sewage treatment plant that changes from moment to moment with the state at the time of execution of the most recent optimal control process, and if the difference exceeds a specified value, the power supply reserve capacity, the operating cost, operating efficiency, and CO ₂ emission amount of each target value, punishment function (control conditions), and the weight coefficient may be corrected. Thereby, the process of step S2 is completed and the optimal control process proceeds to the process of step S3.

  In the process of step S3, the supply and demand adjustment unit 104a determines the excess or deficiency of the power supply capacity within a predetermined period by the same method as the process of step S1, based on the adjustment procedure determined by the process of step S2. In this process, the supply and demand adjustment unit 104a may determine whether the power supply capacity is excessive or insufficient in consideration of whether the power supply capacity has a reserve capacity corresponding to a predetermined percentage of the power demand. In addition, as a result of this process, when an excess or deficiency in power supply capacity that exceeds a predetermined threshold value occurs, the supply and demand adjustment unit 104a executes the process of step S3 again, so that the excess or deficiency in power supply capacity is less than the threshold value. Adjust the power supply and demand plan so that Thereby, the process of step S3 is completed, and the optimal control process proceeds to the process of step S4.

  In the process of step S4, the supply and demand control unit 104b controls the power demand and the power supply capacity of the sewage treatment plant by controlling the load facility and the power generation facility according to the adjustment procedure determined by the process of step S3. Thereafter, the evaluation function correction unit 104c calculates a difference value between the power demand and power supply capacity controlled by the supply and demand control unit 104b and the actual power demand and power supply power, and based on the calculated difference value. The model for predicting the evaluation function H and the power supply / demand plan is corrected. In this process, the supply and demand control unit 104b may display information on the past and present operation status of the sewage treatment plant and information on the operation plan of the sewage treatment plant on the GUI screen. Thereby, the process of step S4 is completed and a series of optimal control processes are complete | finished.

As is clear from the above description, according to the series of optimal control processes of the present invention, the supply and demand adjustment unit 104a has the power demand amount in the sewage treatment plant adjusted based on the power supply and demand prediction in the sewage treatment plant and An evaluation function that uses the data on supply capacity to calculate the power supply reserve capacity of the sewage treatment plant, operating costs, operating efficiency, and CO ₂ emissions relative to the target values, and includes the calculated deviation and penalty function as variables. Is calculated as an optimization model of a sewage treatment plant. Then, the supply and demand control unit 140b controls the operation of the sewage treatment plant according to the calculated optimization model. As a result, the sewage treatment plant can be optimally controlled with high accuracy regardless of the timing of executing the optimal control.

  Although the embodiment to which the invention made by the present inventor is applied has been described above, the present invention is not limited by the description and the drawings that form part of the disclosure of the present invention according to this embodiment. That is, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on the present embodiment are all included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Sewage treatment equipment 2 Sludge treatment equipment 11 Sedimentation basin 12 First sedimentation basin 13 Reaction tank 14 Final sedimentation basin 15 Chemical injection tank 16 Sewage pump 17a, 17b Sludge scraping machine 18 Sludge extraction pump 19 Blower 20 Pressure gauge 21 Chemical injection pump 31 Concentration tank 32 Digestion tank 33 Dehydrator 34 Incinerator 100 Optimal control system 101 Actual data database 102 Supply and demand plan database 103 Input device 104 Optimal control device 104a Supply and demand adjustment unit 104b Supply and demand control unit 104c Evaluation function correction unit 105 Output device

Claims (3)

Targets for power supply reserve capacity, operating cost, operating efficiency, and CO ₂ emissions of plant equipment using data on demand and supply capacity of power in plant equipment adjusted based on power supply and demand forecast in plant equipment A calculating step for calculating a deviation from the value;
The data regarding the operation status of the plant equipment at the execution timing of the optimization process is compared with the data regarding the supply and demand plan of the plant equipment at the execution timing of the immediately previous optimization process, and when the difference is a predetermined value or more, the deviation is an evaluation function including as a variable, a correction step of correcting the adjustment of the variable constituting the evaluation function,
An optimization step of calculating an optimal solution of the corrected evaluation function as an optimization model of the plant equipment;
A control step for controlling operation of the plant equipment according to the optimization model;
An optimal control method for plant equipment, comprising: The method for optimal control of plant equipment according to claim 1, further comprising the step of displaying information relating to the operation status of past and present plant equipment and information relating to an operation plan of the plant equipment. Targets for power supply reserve capacity, operating cost, operating efficiency, and CO ₂ emissions of plant equipment using data on demand and supply capacity of power in plant equipment adjusted based on power supply and demand forecast in plant equipment A calculation means for calculating a deviation from the value;
When comparing the data relating to supply and demand planning of the plant equipment in the execution timing of the optimization process of the immediately preceding data related to the operation status of the plant equipment in the execution timing of the optimization process, the difference is a predetermined value or more, the deviation an evaluation function of containing as a variable, and correction means for correcting the adjustment of the variable constituting the evaluation function,
An optimization means for calculating an optimal solution of the corrected evaluation function as an optimization model of the plant equipment;
Control means for controlling operation of the plant equipment according to the optimization model;
An optimum control device for plant equipment, comprising:

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