JP6676445B2 - Maintenance planning support system for power generation units - Google Patents

Description

  The present invention relates to a maintenance plan support system for a power generation unit group.

  For example, power plants such as coal-fired power plants use a soot blower that injects high-temperature steam periodically because ash adheres to the heat exchanger of the coal boiler during operation, reducing the efficiency of heat transfer from gas to steam. The heat transfer efficiency is suppressed by removing the attached ash. However, it is difficult to completely remove the ash, which reduces the heat transfer efficiency over time and consequently increases the fuel cost with increased fuel consumption.

  On the other hand, in order to suppress the increase in the fuel consumption as described above, maintenance (cleaning) of the heat exchanger of the boiler is performed. This cleaning is to remove the dirt attached to the heat exchanger by hand, and it is necessary to build a scaffold depending on the location in the boiler, so that the maintenance cost is high. Therefore, it is not advisable to carry out the above-mentioned cleaning frequently, and it is effective to formulate a maintenance plan in consideration of an increase in fuel cost due to a decrease in efficiency and a maintenance work cost for improving efficiency.

  To adjust such a rise in the fuel cost and the time of the maintenance work, the total cost is calculated from the increase in the fuel cost due to the decrease in the efficiency during the operation of the power generation unit and the maintenance work cost for improving the efficiency. A method for determining the timing of maintenance work has been proposed (for example, see Patent Document 1). According to this method, in the cleaning operation of the gas turbine compressor, a point in time when the cost increase due to the efficiency deterioration of the compressor becomes equal to the cleaning cost is determined as the optimal maintenance operation time when the cost is minimized.

JP 2005-133584 A

  In the method according to the above-described conventional technology, the cleaning operation of the gas turbine compressor is completed in a short period of about 1 to 2 days. You only have to work on the weekend.

  However, depending on the contents of the maintenance work, it may be necessary to stop the plant for a long time. For example, when cleaning the inside of a coal boiler, it takes a long time to lower the temperature after the plant is stopped. Therefore, it may take a wait time for a maintenance worker to enter the inside and several weeks to assemble a scaffold in the boiler.

  In addition, in the case of a power generation company that supplies power using a plurality of power generation units, it is not possible to determine the maintenance work execution time by the power generation plant alone. That is, when the maintenance work periods of a plurality of power generation units overlap, a situation may occur in which the amount of power supply is insufficient for the power demand, or the number of personnel for the maintenance work cannot be secured.

  The present invention has been made based on the above-described circumstances, and an object of the present invention is to be able to consider a loss cost across a plurality of power generation units, and to efficiently reduce power generation unit groups as a whole. An object of the present invention is to provide a maintenance plan support system for a group of power generation units that can reduce the total cost by making a maintenance plan.

The present invention
(1) A maintenance plan support system for a power generation unit group that supports a maintenance plan for a power generation unit group including a plurality of power generation units,
An efficiency calculator for analyzing the efficiency of each of the power generation units,
A fuel loss cost calculation unit for determining a fuel loss cost due to excessive consumption of fuel due to the decrease in efficiency;
A loss cost calculator for calculating a loss cost for each power generation unit based on a fuel loss cost and a maintenance work cost for improving efficiency;
A maintenance plan support system for a power generation unit group (hereinafter, also simply referred to as a “system”), comprising: a total cost calculation unit that calculates a total cost of the plurality of power generation units based on the loss cost.
(2) The maintenance planning support system for a power generation unit group according to (1), wherein the loss cost is a difference between a fuel loss cost and a maintenance work cost in each power generation unit.
(3) The fuel cell system according to (1), further comprising: a fuel loss cost predicting unit that obtains a fuel loss cost trend from the tendency of the efficiency change, and obtains a fuel loss cost predicted to occur at the next maintenance work from the trend. (2) the maintenance plan support system for the power generation unit group,
(4) From the above (1), further comprising a suppliable power calculation unit for obtaining suppliable power of the entire power generation unit group based on the maintenance plan in a time-series manner so as to be able to compare with the predicted trend of the power demand. (3) The maintenance plan support system for a power generation unit group according to any one of (3),
(5) The number of maintenance workers is further provided to calculate the number of maintenance workers required in the entire power generation unit group based on the maintenance plan in chronological order so as to be able to compare with the predicted trend of the number of maintenance workers that can be secured. The maintenance plan support system for a power generation unit group according to the above (4),
(6) The power generation unit according to any one of (1) to (5), wherein the fuel loss cost and the maintenance work cost are obtained based on whether or not maintenance work is performed for each device constituting the power generation unit. Group maintenance planning support system,
(7) The maintenance planning support system for a power generation unit group according to (6), wherein the power generation unit is a thermal power generation unit, and the equipment is a heat exchanger of a boiler.
(8) further comprising an automatic planning unit for automatically planning maintenance of the power generation unit group based on the total cost;
The automatic planning unit is configured such that the power sought in chronological order by the suppliable power calculation unit is equal to or greater than the predicted power demand, and the predicted number of securable maintenance workers is chronologically calculated by the maintenance worker number calculation unit. The maintenance plan support system for a power generation unit group according to the above (5), wherein a maintenance plan is drafted so that the total cost becomes a minimum value under a condition that the number of maintenance workers is equal to or more than a required number of maintenance workers.
(9) The power supply unit further includes a supply power correction unit that corrects power that can be supplied to each power generation unit,
(10) The power generation unit group maintenance plan support system according to any one of (1) to (8), wherein the total cost is obtained again based on the power plan corrected by the supply power correction unit. The power generation according to any one of (1) to (9), further including a load distribution calculation unit that performs economical load distribution based on a correspondence relationship between a power load and a fuel loss cost for each power generation unit. The present invention relates to a maintenance plan support system for a unit group.

  In this specification, “economic load distribution” refers to a load distribution to each power generation unit when minimizing the total cost for a power generation unit group having at least two or more power generation units having different efficiencies. means.

  The present invention provides a power generation unit group that can consider the loss cost across a plurality of power generation units and can reduce the total cost by drafting an efficient maintenance plan for the whole power generation unit group. A maintenance plan support system can be provided.

FIG. 2 is a schematic block diagram illustrating a configuration of first and second embodiments of the present invention. FIG. 2 is a schematic diagram illustrating an example of a configuration of a process value database in FIG. 1. FIG. 2 is a schematic diagram illustrating an example of a configuration of a fuel unit price database of FIG. 1. It is the schematic which shows the concept at the time of calculating | requiring the increasing tendency of the fuel loss cost with the fall of efficiency, (a) is a relationship between elapsed time and a fuel loss cost, (b) is a relationship between an electric energy and fuel loss cost. The relationships are shown below. It is the schematic which shows an example of a structure of the operation plan database of FIG. It is the schematic which shows the concept at the time of calculating | requiring a total cost from a fuel loss cost and a maintenance work cost. FIG. 2 is a schematic diagram illustrating an example of an operation screen (a screen before correction of a regular inspection process) in the input / output device of FIG. 1. FIG. 2 is a schematic diagram illustrating an example of an operation screen (correction screen of a regular inspection process) in the input / output device of FIG. 1. FIG. 2 is a schematic diagram illustrating an example of a configuration of a regular inspection database in FIG. 1. FIG. 2 is a schematic diagram illustrating an example of an operation screen (a screen after correction of a regular inspection process) in the input / output device in FIG. 1. FIG. 2 is a schematic diagram illustrating an example of an operation screen (a screen for confirming a power supply amount and maintenance staff) in the input / output device in FIG. 1. It is the schematic which shows an example of a structure of the electric power demand database of FIG. FIG. 2 is a schematic diagram illustrating an example of a configuration of a worker database in FIG. 1. FIG. 2 is a schematic diagram illustrating an example of a configuration of a plant information database in FIG. 1. FIG. 2 is a schematic diagram illustrating an example of an operation screen (operation plan setting screen) in the input / output device in FIG. 1. FIG. 11 is a schematic diagram illustrating an example of an operation screen (maintenance work content correction screen) in the input / output device in FIG. 1 according to the second embodiment of the present invention. It is the schematic which shows an example of a structure of the fixed inspection database of FIG. 1 in 2nd Embodiment of this invention. It is a schematic diagram showing an example of composition of a plant information database of Drawing 2 in a 2nd embodiment of the present invention. FIG. 11 is a schematic block diagram illustrating a configuration of a third exemplary embodiment of the present invention. FIG. 20 is a schematic diagram illustrating an example of a configuration of a plant efficiency database in FIG. 19. FIG. 20 is a schematic diagram illustrating an example of an operation screen (a screen after correction of a regular inspection process) in the input / output device in FIG. 19.

  A maintenance plan support system for a power generation unit group according to the present invention is a maintenance plan support system for a power generation unit group that supports a maintenance plan for a power generation unit group including a plurality of power generation units. A calculation unit, a fuel loss cost calculation unit for obtaining a fuel loss cost due to excessive consumption of fuel due to the decrease in efficiency, and a loss cost for each power generation unit based on the fuel loss cost and maintenance work cost for improving efficiency. It is characterized by comprising a loss cost calculation unit to be calculated and a total cost calculation unit to calculate a total cost of the plurality of power generation units based on the loss cost.

  The power generation unit group for which the system supports a maintenance plan has at least one power plant including one or more power generation units ("power generation units" are also simply referred to as "units"), and a plurality of power generation units as a whole are provided. It consists of a power generation unit.

  As described above, since the system includes the efficiency calculation unit, the fuel loss cost calculation unit, the loss cost calculation unit, and the total cost calculation unit, the loss cost can be considered across a plurality of power generation units. Thus, the total cost can be reduced by drafting an efficient maintenance plan for the entire power generation unit group.

  Here, the power generation unit for which the system supports the maintenance plan is not particularly limited, but is preferably a thermal power generation unit, and the equipment to be maintained is preferably a boiler heat exchanger. As described above, by applying the system to the thermal power generation unit, the total cost in the thermal power generation unit group can be more effectively reduced.

  Hereinafter, first to third embodiments of the system will be described with reference to the drawings, but the present invention is not limited to only the embodiments described in the drawings.

[First Embodiment]
FIG. 1 is a schematic block diagram showing the configuration of the first embodiment of the present invention. As shown in FIG. 1, the system S1 schematically includes a process value database 101, an efficiency calculation unit 201, a fuel loss cost calculation unit 202, a fuel loss cost prediction unit 203, and a loss cost calculation unit 204. , A total cost calculation unit 205 and a constraint condition processing unit 206.

  The process value database 101 stores measurement data taken from each power generation unit of the power generation unit group. The measurement data is data (signal A, signal B, etc.) for each power generation unit as shown in FIG. 2, for example, and is stored in the process value database 101 in a time-series manner. . Further, the process value database 101 stores a fuel code, which will be described later, together with the sensor signal value in the plant.

  The efficiency calculation unit 201 analyzes the efficiency of each power generation unit. Specifically, the efficiency calculation unit 201 calculates the efficiency of each device constituting the power generation unit, or calculates the efficiency of each power generation unit, using the measurement data stored in the process value database 101. For example, in the case of a coal-fired power plant, the above-mentioned efficiency is the efficiency of the boiler room (boiler room efficiency ηb) represented by the following expression (1) and the efficiency of the turbine room (turbine room efficiency) represented by the following expression (2). ηt). Further, these derived results are stored in the efficiency database 102 in time series.

  The fuel loss cost calculation unit 202 calculates a fuel loss cost due to excessive consumption of fuel due to the decrease in the efficiency based on the efficiency value calculated by the efficiency calculation unit 201. The fuel loss cost calculation unit 202 is calculated using, for example, the following equations (3), (4), and (5).

  The above equation (3) is an equation for obtaining the flow rate of the fuel excessively consumed due to the decrease in the efficiency, based on the boiler room efficiency ηb and the turbine room efficiency ηt calculated by the efficiency calculation unit 201. Here, a reduction in the efficiency of the boiler among the devices constituting the power generation unit will be exemplified. The excess fuel consumption is determined from the deviation of the actual efficiency ηb from the boiler room efficiency reference value ηb0. Here, the boiler room efficiency reference value ηb0 uses a value corrected under operating conditions such as load and coal composition.

  The above equation (4) is an equation for converting excess fuel consumption into cost. The information of the fuel unit price used for this conversion is stored in the fuel unit price database 103. In the present embodiment, for example, as shown in FIG. 3, the fuel unit price database 103 stores a coal type (type of fuel), a fuel code assigned to each coal type, and a fuel unit price corresponding to the fuel code. Have been. Using these, the fuel loss cost calculation unit 202 fetches the data of the fuel unit price corresponding to the coal type code, and calculates the fuel cost for the excess fuel consumption. The loss cost obtained by the above equation (4) is a loss cost per hour, and represents an instantaneous value according to the operating condition of the power generation unit and the state of efficiency deterioration.

  The above equation (5) is an equation for calculating the total amount of loss costs that have occurred up to the present time (when calculating the loss cost; the same applies hereinafter). By using this equation and accumulating the loss cost per hour obtained by equation (4) on the basis of, for example, immediately after a periodic inspection (also referred to as “periodic inspection” in this specification), the loss cost caused by the efficiency deterioration is obtained. Ask for.

  The calculation result of the loss cost calculated by the fuel loss cost calculation unit 202 as described above is stored in the fuel loss cost database 104 in time series.

  The fuel loss cost prediction unit 203 obtains a trend of the fuel loss cost from the tendency of the efficiency to change, and obtains a fuel loss cost predicted to occur at the next maintenance work from the trend. Here, the concept of obtaining the trend of the fuel loss cost accompanying the change (decrease) in efficiency will be described with reference to FIG. In FIG. 4A, the horizontal axis represents the elapsed time immediately after the regular inspection, which is the basis of the efficiency evaluation. The elapsed time and the fuel loss cost (the loss cost per hour output by the fuel loss cost calculation unit 202) are shown. Shows the relationship.

  By the way, when performing partial load operation, etc., the speed of progress of the efficiency deterioration also changes. Can be In order to exclude such a temporary effect, the fuel loss cost prediction unit 203 converts the horizontal axis into the electric energy immediately after the regular inspection and changes the fuel loss cost as shown in FIG. 4B, for example. Figure out. In the example shown in FIG. 4B, the rate of increase in fuel loss cost per time, that is, the rate of progress of efficiency reduction is evaluated based on the slope obtained by linear approximation.

  The fuel loss cost prediction unit 203 predicts a fuel loss cost that will be generated in the future, for example, by calculation using Expressions (6), (7), and (8) below.

  The above equation (6) is an equation for calculating a predicted value of the accumulated power amount P (T) after the elapse of the T time with reference to the present time. In this equation, the planned value W (T) of the power generation load is used. The data on the planned value of the power generation load is stored in the operation plan database 105 (see FIG. 1) for each power generation unit as shown in FIG. For example, in the example of FIG. 5, in the unit 1 of the B power plant, the load is reduced to 1,000 MW at 19:00 on December 1, 2015, to 300 MW at 20:00 one hour later, The operation plan database 105 stores the planned value of the power generation load that the operation is performed until 7:00 on the 2nd and the load is increased to 1,000 MW one hour later at 8:00.

The above equation (7) is an equation for calculating a predicted value of the per-hour fuel loss cost Cp (T) after the elapse of the T time with reference to the present time. In the equation (7), the change rate a of the fuel loss cost per hour is a slope obtained by linearly approximating the change in the fuel loss cost, as shown in FIG. In the future (after the calculation of the loss cost), the change in the fuel loss cost is used assuming that it follows the change rate a. Accordingly, the predicted value of the fuel penalty cost Cp (T), as shown in the equation (7), the fuel penalty cost C ₀ per current time fuel penalty cost calculation unit 202 is determined, accumulated from the current It is obtained by adding according to the electric energy P (T).

The above equation (8) is a predicted value of the fuel loss cost Lp (T) after the elapse of the T time with respect to the present time. The predicted value is a cumulative value of the fuel loss cost per hour obtained by the equation (7). Specifically, the predicted value, as shown in the equation (8), fuel penalty cost calculation unit 202 is determined by going added to the current fuel penalty cost L ₀ obtained.

  As described above, since the system S1 includes the fuel loss cost prediction unit 203, it is possible to more accurately grasp the loss cost at the time of maintenance work, and to draft a more appropriate maintenance plan. The calculation result of the predicted value of the fuel loss cost calculated by the fuel loss cost prediction unit 203 is stored in the fuel loss cost database 104 in time series.

  The loss cost calculation unit 204 calculates a loss cost for each power generation unit based on a fuel loss cost and a maintenance work cost for improving efficiency. The loss cost is, for example, a difference between the fuel loss cost and the maintenance work cost in each power generation unit. As the fuel loss cost, any one of the fuel loss cost obtained by the fuel loss cost calculation unit 202 and the fuel loss cost obtained by the fuel loss cost prediction unit 203 can be adopted. The maintenance work cost is a cost for the purpose of improving the efficiency of the power generation unit, and includes, for example, all costs required for maintenance work such as labor costs and material costs for cleaning equipment constituting the power generation unit. This is the total cost.

  In the present embodiment, the fuel loss cost obtained by the fuel loss cost prediction unit 203 is exemplified. Therefore, the system S1 predicts the value of the fuel loss cost on the regular inspection start date (planned period) of each unit from the trend of the fuel loss cost obtained by the fuel loss cost prediction unit 203. The difference from the cost is calculated as the loss cost. Thereby, in order to reduce the total cost, it is possible to grasp a more appropriate maintenance work timing for each power generation unit.

  The condition under which the loss cost for each power generation unit is minimized is when the fuel loss cost and the maintenance work cost match as shown in FIG. The above-mentioned loss cost for each power generation unit is stored in the loss database 106 for each power generation unit.

  The total cost calculation unit 205 calculates the total cost of the plurality of power generation units based on the loss cost of each power generation unit. The total cost calculation unit 205 calculates the total loss cost by adding the loss costs for each power generation unit calculated by the loss cost calculation unit 204. Thereby, the cost of the whole power generation unit group can be grasped.

  The constraint condition processing unit 206 calculates, for each of the power and the number of maintenance workers, the difference between the predicted demand and the supply that can be secured at each time. As shown in FIG. 1, the constraint condition processing unit 206 includes a suppliable power calculation unit 207 and a maintenance worker number calculation unit 208.

  The suppliable power calculation unit 207 obtains the suppliable power of the entire power generation unit group based on the maintenance plan in time series so as to be able to compare the predicted power demand trend. Specifically, information on the regular inspection process of each unit stored in the regular inspection database 107, the rated power of each unit of each power plant stored in the plant information database 109, and the number of personnel required for the regular inspection work. Using the data such as information (see FIG. 14), the suppliable amount of power is calculated by summing the rated powers of the units that can be operated, that is, the units that are not under regular inspection.

  The number of maintenance workers calculation unit 208 obtains the number of maintenance workers required in the entire power generation unit group based on the maintenance plan in a time-series manner so as to be able to compare with the predicted trend of the number of maintenance workers that can be secured. More specifically, information on the periodic inspection process of each unit stored in the periodic inspection database 107, and information on the number of secured workers at the preliminary inspection input in advance stored in the worker database 108 (FIG. 13), and the data stored in the plant information database 109, such as the rated power of each unit of each power plant and the information of the personnel required for the periodic inspection work (see FIG. 14). The number of maintenance workers is calculated.

  In addition, the above-described constraint condition processing unit 206 relates to the demand calculated in advance based on the power obtained by the above-mentioned suppliable power calculation unit 207 and the annual power demand obtained from the power demand database 110. From the predicted value (see FIG. 12). Further, the constraint condition processing unit 206 relates to the number of maintenance workers calculated by the above-described maintenance worker number calculation unit 208 and the number of maintenance workers acquired in advance from the worker database 108 at the regular inspection. Then, the difference is calculated from the number of secured persons (see FIG. 13). The above-described data on the power and the number of maintenance workers calculated by the constraint processing unit 206 are stored in the constraint database 111.

  As described above, the constraint condition processing unit 206 includes the above-described suppliable power calculation unit 207 and calculates the difference between the powers, so that the system S1 determines whether the suppliable power satisfies the power demand. Can be confirmed, and shortage of power supply can be reliably avoided. Further, the constraint condition processing unit 206 includes the above-described number of maintenance workers calculation unit 208 and calculates the difference in the number of workers, so that the system S1 can confirm whether the number of workers is sufficient. It is possible to reliably avoid shortage of workers.

  Next, an example of a procedure for performing a maintenance plan of the power generation unit group will be described. The maintenance plan is determined so as to reduce the total cost while setting, for example, constraints on plant operation in consideration of the maintenance work of each unit of the power plant as close as possible to an optimum date. Hereinafter, the maintenance plan optimization processing will be described.

  FIG. 7 is a schematic diagram showing an example of an operation screen (a screen before correction of the regular inspection process) in the input / output device 200 of FIG. As shown in FIG. 7, the regular inspection process of each unit in each power plant is displayed on the operation screen G1. This operation screen G1 shows a process planned in advance, and is in a state before optimization. The power generation unit has a statutory inspection deadline, and the deadline for boilers in Japan is two years. In other words, the boiler can be operated without regular inspection up to two years. The legal inspection deadline is displayed on the operation screen G1 shown in FIG.

  In addition, the operation screen G1 displays the loss cost obtained by the above-described calculation, and when the maintenance plan is corrected, the amount of increase or decrease of the loss cost (the amount of change after the process correction) calculated by the correction is further displayed. Is displayed. Here, since the operation screen G1 in FIG. 7 is in a state before the process is corrected, the increase / decrease amount after the process correction is not displayed. The information such as the periodic inspection period displayed on the operation screen is stored in the periodic inspection database 107, the power generation unit-specific loss database 106, and the like shown in FIG. The above-mentioned regular inspection database 107 contains, for each unit of each power plant, the regular inspection start date and the end date (the originally planned regular inspection period and the regular inspection period after the correction by the system S1), the legal Inspection deadlines, boiler maintenance costs, and the like are stored, and the power generation unit-specific loss database 106 stores the above-described power generation unit-specific loss costs.

  Next, correction of a maintenance plan (process) will be described. Here, an example in which the unit 2 of the power plant A is selected as the unit to be corrected from the power generation unit group shown in FIG. 7 will be described. In the original plan, the scheduled inspection was scheduled for the period from May 20, 2015 to July 10, 2015, but this period has been moved forward from the period from April 1, 2015 to May 20, 2015. It has been modified to be.

  At that time, as shown in FIG. 8, the regular inspection start date is corrected so as to be closer to the date on which the loss cost is minimized (optimal date). As a result, it is understood that the loss cost of the unit 2 is reduced from 225 M $ to 5 M $, and a cost reduction effect of 220 M $ is obtained. FIG. 9 is a schematic diagram showing an example of the configuration of the regular inspection database 107 in FIG. When the above-mentioned corrected inspection process is registered, the data of the corrected process is stored in the above-described inspection database 107 from the loss cost calculator 204 as shown in FIG.

  Next, a maintenance plan of the entire power generation unit group including the above-described process modification for the unit 2 of the power plant A is displayed. At this time, the total cost calculation unit 205 calculates the total cost of the plurality of power generation units as a whole by adding the loss costs for each power generation unit calculated by the loss cost calculation unit 204. FIG. 10 is a schematic diagram showing an example of the operation screen G3 (the screen after the correction of the regular inspection process) in the input / output device 200 of FIG. As shown in this figure, the process of the unit 2 of the power plant A has been corrected at an early stage, and the loss cost associated with this correction and the increase / decrease after the process correction are displayed on the operation screen G3. Although not described in detail, the process of the unit 2 of the power plant B is modified at a later time so as to replace the process of the unit 2 of the power plant A. By performing such an operation, it is possible to reduce the total cost of the plurality of power generation units as a whole, while avoiding concentration of regular inspections of the plurality of units.

  Next, from the viewpoint of plant operation, it is confirmed whether or not there is any problem in the process after the correction. FIG. 11 is a schematic diagram showing an example of an operation screen (a screen for confirming the power supply amount and the number of maintenance workers) in the input / output device 200 in FIG. In the present embodiment, the confirmation of the power supply amount and the number of maintenance workers for the regular inspection work is illustrated. More specifically, the predicted value of the power demand and the suppliable power obtained by the suppliable power calculation unit 207, and the required number of workable and maintenance workers calculated by the unit 208 that can be secured and the number of maintenance workers are required. The number of maintenance workers is displayed on the operation screen G4 in chronological order.

  Here, the system S1 further includes a supply power correction unit (not shown) that corrects the power that can be supplied to each power generation unit so that an operation plan can be set for each power generation unit. The total cost may be calculated again based on the power plan that has been set. As a specific example, for example, FIG. 15 illustrates an operation plan with a rated load of 1,000 MW in the daytime and a partial load of 300 MW in the nighttime. When such an operation plan is registered by the user, the fuel loss cost prediction unit 203 performs prediction in accordance with the data. As described above, the rate of progress of the fuel loss cost due to the reduction in efficiency changes according to the amount of electric power. Therefore, if the operation plan is changed to a low-load operation plan, the temporal change rate of the fuel loss cost becomes moderate. As described above, since the system S1 further includes the supply power correction unit, the initial operation plan can be corrected, and the total cost can be reliably reduced based on the correction.

  The system S1 further includes an automatic planning unit 210 that automatically plans maintenance of the power generation unit group based on the total cost. Is greater than or equal to the predicted power demand, and the total cost is less than or equal to the predicted number of maintenance workers that can be secured and is greater than or equal to the number of maintenance workers determined in time series by the maintenance worker number calculation unit 208. A maintenance plan may be drafted so as to have a minimum value.

  The automatic planning unit 210 includes, for example, the optimization processing unit 211 shown in FIG. The optimization processing unit 211 uses the total cost calculated by the total cost calculation unit 205 as an evaluation function to make it close to the minimum, and the power supply amount calculated by the constraint condition processing unit 206 and the maintenance worker have a margin. The operation plan is determined so that the scheduled inspection period is secured and the scheduled inspection time does not exceed the legal inspection deadline acquired from the inspection database 107.

  As a method of automatically determining the operation plan, for example, a method of automatically calculating by a scheduling process based on an integer programming is cited. In this method, for each unit, the day on which the regular inspection is performed is defined as 1, and the day on which the regular inspection is not performed is defined as 0. Thus, the arrangement of 1s and 0s for each day indicates the operation plan of each unit. In the above-described scheduling process, a sequence of 1s and 0s is obtained so that the evaluation function is minimum and satisfies the constraint condition. Note that, as a scheduling method for more efficiently searching for an optimal solution, various methods such as a general method such as a branch and bound method or a method using a genetic algorithm can be appropriately employed.

  As described above, since the system S1 includes the automatic planning unit 210, a maintenance plan can be quickly and reliably drafted.

[Second embodiment]
In the system according to the second embodiment, the fuel loss cost and the maintenance work cost are obtained based on whether or not the maintenance work is performed for each device constituting the power generation unit. The second embodiment is different from the first embodiment in that it is determined whether or not maintenance work is to be performed for each device constituting each power generation unit. Specifically, in the first embodiment, the fuel loss cost is obtained from the efficiency of the entire boiler, and the maintenance work of the entire boiler is performed. However, in the second embodiment, the fuel loss cost for each heat exchanger such as a furnace is used. And select the equipment that requires maintenance.

  Hereinafter, a second embodiment will be described with reference to FIGS. Note that the system S2 is the same as the configuration in FIG. 1 except for the configuration of the database and some calculation contents, and therefore, the system in FIG. 1 is used. Except for the following description, since the configuration is the same as that of the first embodiment, the description of the first embodiment will be omitted.

  FIG. 16 shows an example of the operation screen when the maintenance work content is corrected in the present embodiment. On this operation screen G6, the predicted value of the fuel loss cost (here, the furnace loss, the secondary superheater, the tertiary superheater, the reheater, the primary superheater, and the economizer) as the various heat exchangers constituting the boiler is used. , The currently planned fuel loss cost at the start of regular inspection) is displayed. The operation screen G6 also displays, for each of the various heat exchangers, the cost that can be reduced when the maintenance work such as cleaning is omitted and the number of days that can be shortened for the regular inspection period.

  In this operation screen G6, the prediction of the fuel loss cost of the furnace is small, the cost that can be reduced when the cleaning operation is omitted is large, and the number of days that can be shortened for the regular inspection is long. Therefore, in the regular inspection this time, it can be determined that the cleaning operation of the furnace is omitted. The heat exchanger for which the maintenance work is omitted presses the check button of the work skip and registers the data. Thus, the maintenance plan can be optimized under the condition where the cleaning operation is omitted.

  As shown in FIG. 17, in the regular inspection database 107 of the system S2, in addition to the data of FIG. 9, the reduction when the maintenance work (cleaning work) of various heat exchangers such as a furnace and a secondary superheater is omitted. Data on costs and the number of days that can be shortened for periodic inspection work have been added. Note that these data are the data displayed on the operation screen G6 described above. In addition, as shown in FIG. 18, in addition to the data in FIG. 4, the number of regular inspection days is added to the plant information database 109 of the system S2.

  In the system S2, first, the efficiency calculating unit 201 calculates the heat transmission coefficient of each heat exchanger, which is an index of the heat transfer efficiency, using the following equation (9).

  Here, if dirt adheres to the pipes of the various heat exchangers, the heat transfer efficiency decreases in accordance with the degree thereof, and as a result, the value of the heat transmission coefficient also decreases. Therefore, the fuel loss cost calculation unit 202 obtains a fuel flow rate excessively consumed due to contamination of the pipe from the difference between the calculated current value of the heat transmission coefficient and the reference value. Specifically, the heat balance of the boiler is calculated, the amount of decrease in the boiler room efficiency corresponding to the amount of decrease in the heat transfer rate of each heat exchanger is obtained, and this is converted into a fuel flow rate.

  Next, similarly to the first embodiment, after the fuel loss cost calculation unit 202 obtains the fuel loss cost up to the present using the above-described value of the excessively consumed fuel flow rate, the fuel loss cost prediction unit 203 And the fuel loss cost expected to occur at the next maintenance work.

  Next, when, for example, the omission of the furnace operation is selected on the operation screen G6 shown in FIG. 16, the information that the maintenance cost can be reduced by 50 M ￥ and the number of days for which the regular inspection can be shortened are reflected by seven days, and the information shown in FIG. 50M $ is subtracted from the maintenance cost stored in the inspection database 107, the regular inspection end date is moved forward by seven days, and the total cost is revised by the total cost calculation unit 205. Note that, as in the first embodiment, the total cost may be minimized by the optimization processing unit 211 in the automatic planning unit 210.

  As described above, in the system S2, since the fuel loss cost and the maintenance work cost are obtained based on whether or not the maintenance work is performed for each device constituting the power generation unit, the maintenance of the device with low priority is excluded. Min, maintenance work cost and maintenance period can be reduced, and the total cost can be effectively reduced.

[Third Embodiment]
The system according to the third embodiment further includes a load distribution calculation unit that performs economical load distribution based on the correspondence between the power load and the fuel loss cost for each power generation unit. The third embodiment is different from the first and second embodiments in that a load distribution calculation unit is provided. Hereinafter, a third embodiment will be described with reference to FIGS. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. Except for the following description, since the configuration is the same as that of the first embodiment, the description of the first embodiment will be omitted.

  As shown in FIG. 19, the system S3 is roughly composed of a configuration similar to that described in the system S1, a plant efficiency database 112, a load distribution calculation unit 212, and a load distribution database 113. ing.

  The plant efficiency database 112 stores information on a fuel cost curve for each power generation unit. The “fuel cost curve” is a function representing the correspondence between the power generation output and the fuel cost, as shown in FIG. In general, the lower the power generation output, the lower the efficiency of the power generation unit, and therefore the fuel cost per output tends to increase.

  The load distribution calculation unit 212 calculates a fuel cost when economic load distribution is performed to a plurality of units with respect to the power demand forecast stored in the power demand database 110 as illustrated in FIG. In the processing in the load distribution calculation unit 212, the data of the rated power stored in the plant information database 109 as shown in FIG. 14 and the corrected inspections stored in the inspection database 107 as shown in FIG. Use period data.

  The load distribution calculation unit 212 calculates the fuel cost using the above data, for example, using an evaluation function represented by the following equation (10). At that time, by determining the combination of the unit i and the load Pi such that the value of F (T) is minimized, economical load distribution is performed. The economical load distribution calculated by the load distribution calculation unit 212 is stored in the load distribution database 113.

  Here, the constraint condition of the evaluation function is that the total value of all units of the load Pi matches the power demand P (T) at time T. When the power generation unit stops its operation during the regular inspection period, the load Pi is 0 because no power generation output is obtained. On the other hand, when the power generation unit can be operated not during the regular inspection period, the load Pi is within a predetermined range. In the predetermined range, for example, the upper limit is set to 100% of the rated power, and the lower limit (minimum output) is set to 30% of the rated output.

Further, the load distribution calculation unit 212 may accumulate F (T) for a certain period (for example, one year) using the following equation (11), and obtain the fuel cost F _total during this period.

  The fuel cost before and after the correction in the periodic inspection process is calculated using the above equation (11), and the difference between them is calculated, so that the periodic inspection for the fuel cost when the economic load distribution is performed for the annual power demand. The effect of the process modification can be evaluated.

  Next, an example of the operation screen of the system S3 will be described. FIG. 21 is a schematic diagram showing an example of the operation screen (the screen after the correction of the regular inspection process) in the input / output device of FIG. The operation screen G7 also displays a change in the total cost due to the economic load distribution. In the operation screen G7, the economic load distribution has a negative value, indicating that the power generation amount of the unit having low power generation efficiency has increased with respect to the annual power demand. On the other hand, if the power generation amount of the unit having the high power generation efficiency becomes large, the economic load distribution becomes a positive value. As described above, the system S3 can also evaluate the effect when the economic load distribution is considered.

  Note that, as described above, when there is a difference in plant efficiency between units due to, for example, a large difference in the number of years of operation between power generation units, select a power generation unit with the highest possible efficiency and extend the power generation unit for a long time. It means that driving over the whole can reduce the fuel cost as a whole.

  As described above, the system S3 further includes the load distribution calculation unit 212 that performs economical load distribution based on the correspondence relationship between the power load and the fuel loss cost for each power generation unit. In consideration of the difference between the power generation units, the power supplied from each power generation unit can be optimally allocated, and the total cost can be further reduced.

  It should be noted that the present invention is not limited to the configuration of the above-described embodiment, but is indicated by the appended claims, and is intended to include all modifications within the scope and meaning equivalent to the appended claims. Is done.

  For example, in the above-described embodiment, a system in which the systems S1 to S3 include any of the fuel loss cost prediction unit 203, the suppliable power calculation unit 207, and the number of maintenance workers calculation unit 208 has been described. A system that does not include any of the above, or a system that includes any of these, is also within the scope of the present invention.

  Further, in the above-described embodiment, the systems S1 to S3 in which the loss cost is the difference between the fuel loss cost and the maintenance work cost in each power generation unit have been described, but the loss cost is not limited to the difference.

S1 to S3 Maintenance plan support system for power generation unit group 201 Efficiency calculation unit 202 Fuel loss cost calculation unit 203 Fuel loss cost prediction unit 204 Loss cost calculation unit 205 Total cost calculation unit 206 Constraint condition processing unit 207 Suppliable power calculation unit 208 Maintenance Number of workers calculation unit 210 Automatic planning unit 211 Optimization processing unit 212 Load distribution calculation unit

Claims (10)

A maintenance plan support system for a power generation unit group that supports a maintenance plan for a power generation unit group including a plurality of power generation units,
An efficiency calculator for analyzing the efficiency of each of the power generation units,
A fuel loss cost calculation unit for determining a fuel loss cost due to excessive consumption of fuel due to the decrease in efficiency;
A loss cost calculator for calculating a loss cost for each power generation unit based on a fuel loss cost and a maintenance work cost for improving efficiency;
A total cost calculation unit for calculating a total cost of the plurality of power generation units based on the loss cost.   The maintenance plan support system for a power generation unit group according to claim 1, wherein the loss cost is a difference between a fuel loss cost and a maintenance work cost in each power generation unit.   3. The fuel loss cost predicting unit according to claim 1, further comprising: a fuel loss cost predicting unit that obtains a fuel loss cost trend from the tendency of the efficiency change, and obtains a fuel loss cost predicted to occur at the next maintenance work from the trend. A maintenance plan support system for the power generation units described in the above.   4. The power supply unit according to claim 1, further comprising a suppliable power calculating unit that obtains suppliable power of the entire power generation unit group based on the maintenance plan in a time-series manner so as to be able to compare the predicted power demand trend. A maintenance plan support system for a power generation unit group according to any one of the preceding claims.   The system further includes a maintenance worker number calculation unit that calculates the number of maintenance workers required in the entire power generation unit group based on the maintenance plan in a time-series manner so as to be able to compare with the predicted trend of the number of maintenance workers that can be secured. Item 4. A maintenance plan support system for a power generation unit group according to item 4.   The maintenance plan of the power generation unit group according to any one of claims 1 to 5, wherein the fuel loss cost and the maintenance work cost are obtained based on whether or not maintenance work is performed for each device constituting the power generation unit. Support system.   The maintenance plan support system for a power generation unit group according to claim 6, wherein the power generation unit is a thermal power generation unit, and the equipment is a heat exchanger of a boiler. It further includes an automatic planning unit that automatically plans maintenance of the power generation unit group based on the total cost,
The automatic planning unit is configured such that the power sought in chronological order by the suppliable power calculation unit is equal to or greater than the predicted power demand, and the predicted number of securable maintenance workers is chronologically calculated by the maintenance worker number calculation unit. The maintenance plan support system for a power generation unit group according to claim 5, wherein a maintenance plan is drafted so that the total cost is a minimum value under a condition that the number of maintenance workers is more than the number of maintenance workers required. Further provided is a supply power correction unit that corrects the power that can be supplied to each of the power generation units,
The maintenance plan support system for a power generation unit group according to any one of claims 1 to 8, wherein the total cost is obtained again based on the power plan corrected by the supply power correction unit.   The power generation unit according to any one of claims 1 to 9, further comprising a load distribution calculation unit that performs economical load distribution based on a correspondence relationship between a power load and a fuel loss cost for each power generation unit. Group maintenance planning support system.