Computing device, complete set of equipment, computing method and program product

Abstract

The computing device includes: a performance calculation unit that calculates, for each combination of multiple loads in the plant and multiple atmospheric temperatures around the plant, the performance of the plant before the introduction of a component and the performance of the plant after the introduction of the component; a storage unit that stores a data table indicating the ratio of the operating time of the plant for each of the combinations; and a performance improvement calculation unit that calculates, based on the calculation results of the performance calculation unit and the data table, to what extent the performance of the plant is improved compared to before the introduction of the component when the component is introduced and the plant is operated at the ratio shown in the data table.

Description

Technical Field

[0001] The present invention relates to a computing device, a complete set of equipment, a computing method and a program.

[0002] This application claims priority from Japanese Patent Application No. 2019-119584 filed in Japan on June 27, 2019, the contents of which are incorporated herein by reference. Background Art

[0003] In a power generation plant (hereinafter referred to as a "power generation plant") or the like, parts (including devices) may be replaced or added.

[0004] Patent Document 1 describes a technology related to plant upgrades as a related technology.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-106627 Summary of the Invention

[0008] -Problems to be solved by the invention-

[0009] However, components that are replaced or added to power generation plants often come in multiple varieties, even if they have the same function, but with varying performance and prices. Therefore, a technology is needed to quantitatively and easily determine the degree to which plant performance has improved after the introduction of new components, compared to before the introduction of the new components.

[0010] An object of the present invention is to provide a computing device, a plant, a computing method, and a program that can solve the above-mentioned problems.

[0011] -Methods for solving the problem-

[0012] According to the first embodiment of the present invention, the computing device comprises: a performance calculation unit which calculates the performance of the complete equipment before the introduction of a component and the performance of the complete equipment after the introduction of the component for each combination of a plurality of loads in the complete equipment and a plurality of atmospheric temperatures around the complete equipment; a storage unit which stores a data table indicating the ratio of the operating time of the complete equipment for each combination; and a performance improvement calculation unit which calculates, based on the calculation results of the performance calculation unit and the data table, to what extent the performance of the complete equipment is improved compared to before the introduction of the component when the component is introduced and the complete equipment is operated at the ratio shown in the data table.

[0013] According to a second aspect of the present invention, the arithmetic device according to the first aspect may further include a performance improvement result output unit that outputs a calculation result of the performance improvement calculation unit.

[0014] According to the third aspect of the present invention, in the computing device of the first aspect or the second aspect, the performance of the plant may include at least one of the fuel consumption of the plant, the remaining life of the plant, and the reduction in gas discharged from the plant.

[0015] According to the fourth aspect of the present invention, in the computing device of any one of the first to third aspects, the performance calculation unit may calculate the performance of the complete set of equipment using a coefficient representing the degree of influence of the combination of components on the performance of the complete set of equipment when a plurality of the components are introduced.

[0016] According to a fifth aspect of the present invention, a plant includes: the computing device according to any one of the first to fourth aspects; and a power generation device that supplies electric power corresponding to the load.

[0017] According to the sixth aspect of the present invention, the calculation method includes: calculating the performance of the complete equipment before the introduction of the component and the performance of the complete equipment after the introduction of the component for each combination of multiple loads in the complete equipment and multiple atmospheric temperatures around the complete equipment; storing a data table representing the ratio of the operating time of the complete equipment for each combination; and calculating, based on the calculation result of the performance of the complete equipment and the data table, to what extent the performance of the complete equipment is improved compared with before the introduction of the component when the component is introduced and the complete equipment is operated at the ratio shown in the data table.

[0018] According to the seventh embodiment of the present invention, the program causes the computer to execute: calculating the performance of the complete equipment before the introduction of the component and the performance of the complete equipment after the introduction of the component for each combination of multiple loads in the complete equipment and multiple atmospheric temperatures around the complete equipment; storing a data table representing the ratio of the operating time of the complete equipment for each combination; and calculating, based on the calculation result of the performance of the complete equipment and the data table, to what extent the performance of the complete equipment is improved compared with before the introduction of the component when the component is introduced and the complete equipment is operated at the ratio shown in the data table.

[0019] -Effects of the Invention-

[0020] According to the calculation device, plant, calculation method, and program of the embodiment of the present invention, it is possible to quantitatively and easily determine to what extent the performance of the plant is improved when new components are introduced compared to before the introduction of the new components. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a diagram showing the configuration of a plant according to one embodiment of the present invention.

[0022] Figure 2 This is a diagram showing the configuration of a computing device according to one embodiment of the present invention.

[0023] Figure 3 This is a diagram showing an example of a data table TBL1 in one embodiment of the present invention.

[0024] Figure 4 This is a diagram showing an example of the data table TBL2 in one embodiment of the present invention.

[0025] Figure 5 This is a diagram showing a process flow of a plant according to one embodiment of the present invention.

[0026] Figure 6 This is a schematic block diagram showing the structure of a computer according to at least one embodiment. DETAILED DESCRIPTION

[0027] <Implementation Method>

[0028] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

[0029] The structure of a plant 1 according to one embodiment of the present invention will be described.

[0030] Plant 1 is a power generation plant. For example, plant 1 is a power generation plant that uses GTCC (Gas Turbine Combined Cycle) technology. Specifically, a gas turbine generates primary power using natural gas or other fuel, then uses exhaust heat to generate steam, which is then used in a steam turbine to generate secondary power.

[0031] like Figure 1 As shown, the plant 1 includes a power generation device 10 , a temperature sensor 20 , and a computing device 30 .

[0032] The power generation device 10 generates electricity using a gas turbine and a steam turbine.

[0033] The temperature sensor 20 is installed around the plant 1 and detects the temperature around the plant 1 .

[0034] The calculation device 30 is a device that calculates the degree to which the performance of the plant 1 has improved compared to before the introduction of the new components when the plant 1 is upgraded, that is, when new components (including devices) are introduced into the plant 1 (such as when components are replaced or new components are added). The number of components introduced may be one or more.

[0035] like Figure 2 As shown, the computing device 30 includes a storage unit 301 , a performance calculation unit 302 , a performance improvement calculation unit 303 , and a performance improvement result output unit 304 .

[0036] The storage unit 301 stores various information necessary for processing performed by the arithmetic device 30 .

[0037] For example, the storage unit 301 stores Figure 3 Data table TBL1 is shown. Data table TBL1 shows the ratio of the operating time of plant 1 for each combination of multiple representative loads in plant 1 and multiple representative atmospheric temperatures around plant 1 during operation during a given period (e.g., the past year, scheduled operation for the next month, etc.).

[0038] For example, the storage unit 301 stores Figure 4 The data table TBL2 is shown. The details of the data table TBL2 will be described later.

[0039] For example, Figure 3The data table TBL1 shown is a data table showing the operating performance of the plant 1 over the past year. The data table TBL1 shows that, of the total operating time over the past year, the proportion of time that the plant 1 was operating under the conditions of an atmospheric temperature of 5°C or higher and less than 10°C and a load of 50% or higher and less than 60% of the maximum load was 5%; the proportion of time that the plant 1 was operating under the conditions of an atmospheric temperature of 5°C or higher and less than 10°C and a load of 90% or higher and less than 100% of the maximum load was 12%; the proportion of time that the plant 1 was operating under the conditions of an atmospheric temperature of 5°C or higher and less than 10°C and a load of 100% of the maximum load was 20%; and the proportion of time that the plant 1 was operating under the conditions of an atmospheric temperature of 10°C or higher and less than 10°C and a load of 100% of the maximum load was 20%. Under the conditions of 15°C and a load of 50% to 60% of the maximum load, the proportion of the time when the complete equipment 1 is in operation is 13%; under the conditions of an atmospheric temperature of 10°C to 15°C and a load of 100% of the maximum load, the proportion of the time when the complete equipment 1 is in operation is 15%; under the conditions of 35°C to 40°C and a load of 50% to 60% of the maximum load, the proportion of the time when the complete equipment 1 is in operation is 15%; under the conditions of an atmospheric temperature of 35°C to 40°C and a load of 100% of the maximum load, the proportion of the time when the complete equipment 1 is in operation is 20%.

[0040] In addition, representative values ​​can be used for the above-mentioned atmospheric temperature and load. For example, when the atmospheric temperature is 0°C or higher and less than 5°C, 2.5°C can be used as the representative value; when it is 5°C or higher and less than 10°C, 7.5°C can be used as the representative value; when it is 10°C or higher and less than 15°C, 12.5°C can be used as the representative value; and when it is 35°C or higher and less than 40°C, 37.5°C can be used as the representative value. In addition, when the load is greater than 40% and less than 50% of the maximum load, 45% can be used as a representative value, when the load is greater than 50% and less than 60% of the maximum load, 55% can be used as a representative value, when the load is greater than 60% and less than 70% of the maximum load, 65% can be used as a representative value, when the load is greater than 70% and less than 80% of the maximum load, 75% can be used as a representative value, when the load is greater than 80% and less than 90% of the maximum load, 85% can be used as a representative value, and when the load is greater than 90% and less than 100% of the maximum load, 95% can be used as a representative value.

[0041] The performance calculation unit 302 is Figure 3The performance of plant 1 before and after the component installation is calculated for the same combinations of representative loads and representative atmospheric temperatures in data table TBL1. The performance of plant 1 here refers to plant 1's fuel consumption (including power output and power generation efficiency), plant 1's remaining life, and reductions in NOx and other gases emitted by plant 1.

[0042] For example, the performance calculation unit 302 prepares model parameters for each component constituting the plant 1. For the same combination of load and ambient temperature as in the data table TBL1, the performance calculation unit 302 uses the parameters for each component before the new component is introduced to simulate the performance of the plant 1. Furthermore, for the same combination of load and ambient temperature as in the data table TBL1, the performance calculation unit 302 uses the parameters for each component after the new component is introduced to simulate the performance of the plant 1.

[0043] The performance calculation unit 302 executes a simulation of the performance of the plant 1 using, for example, an application that simulates the performance of the plant 1 (for example, EBSILON (registered trademark) that can perform performance evaluation of various power plants).

[0044] The performance improvement calculation unit 303 obtains the simulation results of the performance calculation unit 302. The performance improvement calculation unit 303 sets the simulation results of the performance of the plant 1 for the parameters of each component before the new component is introduced as 100%, and calculates the percentage of the simulation results of the performance of the plant 1 for the parameters of each component after the new component is introduced. Then, the performance improvement calculation unit 303 uses the calculated results as, for example, Figure 4 Data table TBL2 shown is recorded in storage unit 301. Data table TBL2 is a data table that indicates, for each combination of a plurality of representative loads in plant 1 and a plurality of representative ambient air temperatures around plant 1 during operation within a given period (e.g., scheduled operation for the past year or the next month), the degree to which plant 1's performance improves when a new component is introduced into plant 1 compared to before the component was introduced.

[0045] For example, Figure 4The data table TBL2 shown shows the following cases: when the new component is introduced and the plant 1 is operated under the conditions of an atmospheric temperature of 5°C or higher and less than 10°C and a load of 50% or higher and less than 60% of the maximum load, the performance of the plant 1 is improved by 1% compared to before the component was introduced; when the plant 1 is operated under the conditions of an atmospheric temperature of 5°C or higher and less than 10°C and a load of 90% or higher and less than 100% of the maximum load, the performance of the plant 1 is the same as before the component was introduced; when the plant 1 is operated under the conditions of an atmospheric temperature of 5°C or higher and less than 10°C and a load of 100% of the maximum load, the performance of the plant 1 is improved by 3% compared to before the component was introduced; when the atmospheric temperature is 10°C or higher and less than 15°C and the load is When the plant 1 is operated at a load of 50% or more and less than 60% of the maximum load, the performance of the plant 1 is improved by 1% compared to before the component is introduced. When the plant 1 is operated at an ambient temperature of 10°C or more and less than 15°C and a load of 100% of the maximum load, the performance of the plant 1 is improved by 1% compared to before the component is introduced. When the plant 1 is operated at a temperature of 35°C or more and less than 40°C and a load of 50% or more and less than 60% of the maximum load, the performance of the plant 1 is reduced by 1% compared to before the component is introduced. When the plant 1 is operated at an ambient temperature of 35°C or more and less than 40°C and a load of 100% of the maximum load, the performance of the plant 1 is the same as before the component is introduced.

[0046] The performance improvement calculation unit 303 multiplies the value in the data table TBL1 by the value in the data table TBL2 for each combination of the load and the atmospheric temperature, and then calculates the sum of the multiplication results.

[0047] For example, in Figure 3 The datasheets shown in TBL1 and Figure 4In the case of data table TBL2 shown, the performance improvement calculation unit 303 calculates 0.05 × 1.01 = 0.0505 for the conditions where the ambient temperature is 5°C or higher and lower than 10°C and the load is 50% or higher and lower than 60% of the maximum load. Furthermore, the performance improvement calculation unit 303 calculates 0.12 × 1.00 = 0.12 for the conditions where the ambient temperature is 5°C or higher and lower than 10°C and the load is 90% or higher and lower than 100% of the maximum load. Furthermore, the performance improvement calculation unit 303 calculates 0.20 × 1.03 = 0.2060 for the conditions where the ambient temperature is 5°C or higher and lower than 10°C and the load is 100% of the maximum load. Furthermore, the performance improvement calculation unit 303 calculates 0.13 × 1.01 = 0.1313 for the conditions where the ambient temperature is 10°C or higher and lower than 15°C and the load is 50% or higher and lower than 60% of the maximum load. Furthermore, the performance improvement calculation unit 303 calculates 0.15 × 1.01 = 0.1515 for the conditions where the ambient temperature is 10°C or higher and lower than 15°C, and the load is 100% of the maximum load. Furthermore, the performance improvement calculation unit 303 calculates 0.15 × 0.99 = 0.1485 for the conditions where the ambient temperature is 35°C or higher and lower than 40°C, and the load is 50% or higher and lower than 60% of the maximum load. Furthermore, the performance improvement calculation unit 303 calculates 0.20 × 1.00 = 0.20 for the conditions where the ambient temperature is 35°C or higher and lower than 40°C, and the load is 100% of the maximum load. The performance improvement calculation unit 303 then calculates the sum of the multiplications as 0.0505 + 0.12 + 0.2060 + 0.1313 + 0.1515 + 0.1485 + 0.20 = 1.0078. That is, when new components are introduced and the same operation as in the past year is performed, the performance improvement calculation unit 303 calculates based on the data tables TBL1 and TBL2 that the performance of the plant 1 can be expected to improve by 0.78%.

[0048] The performance improvement result output unit 304 outputs the calculation result of the performance improvement calculation unit 303 .

[0049] For example, the performance improvement result output unit 304 displays the calculation result of the performance improvement calculation unit 303 on a display device.

[0050] Furthermore, the output of the calculation results of the performance improvement calculation unit 303 by the performance improvement result output unit 304 is not limited to displaying the calculation results on a display device. For example, the performance improvement result output unit 304 may print out the calculation results of the performance improvement calculation unit 303 as a printed material using a printer. Furthermore, for example, the performance improvement result output unit 304 may output the calculation results of the performance improvement calculation unit 303 as audio from a speaker.

[0051] In this way, the performance improvement result output unit 304 notifies the customer of the calculation results of the performance improvement calculation unit 303. The customer can thus use the calculation results of the performance improvement calculation unit 303 as a basis for deciding whether to introduce new components, for example, if the difference in profit gained from the performance improvement of the plant 1 is greater than the difference between introducing the new component and introducing the same component as before the introduction of the new component, and thus determine that the customer will gain more by introducing the new component.

[0052] Next, refer to Figure 5 The processing of the plant 1 will be described.

[0053] Furthermore, the storage unit 301 stores a data table TBL1 .

[0054] The performance calculation unit 302 calculates the performance of the plant 1 before and after the components are introduced for the same combinations of representative loads and representative atmospheric temperatures in the data table TBL1 (step S1 ).

[0055] For example, the performance calculation unit 302 prepares model parameters for each component constituting the plant 1. For the same combination of load and ambient temperature as in the data table TBL1, the performance calculation unit 302 uses the parameters for each component before the new component is introduced to simulate the performance of the plant 1. Furthermore, for the same combination of load and ambient temperature as in the data table TBL1, the performance calculation unit 302 uses the parameters for each component after the new component is introduced to simulate the performance of the plant 1.

[0056] The performance calculation unit 302 executes a simulation of the performance of the plant 1 using, for example, an application that simulates the performance of the plant 1 .

[0057] The performance improvement calculation unit 303 obtains the simulation results from the performance calculation unit 302. The performance improvement calculation unit 303 sets the simulation results for the performance of the plant 1 using the parameters of each component before the new component is introduced as 100%, and calculates the percentage of the simulation results for the performance of the plant 1 using the parameters of each component after the new component is introduced (step S2). The performance improvement calculation unit 303 then records the calculated results as data table TBL2 in the storage unit 301 (step S3).

[0058] The performance improvement calculation unit 303 multiplies the value in the data table TBL1 by the value in the data table TBL2 for each combination of load and ambient temperature (step S4 ) and then calculates the sum of the multiplication results (step S5 ).

[0059] The performance improvement result output unit 304 outputs the calculation result of the performance improvement calculation unit 303 (step S6 ).

[0060] For example, the performance improvement result output unit 304 displays the calculation result of the performance improvement calculation unit 303 on a display device.

[0061] The plant 1 according to one embodiment of the present invention has been described above.

[0062] In the computing device 30 of the plant 1, the performance calculation unit 302 calculates the performance of the plant 1 before and after the component is introduced, for each combination of multiple loads in the plant 1 and multiple atmospheric temperatures in the plant 1. The storage unit 301 stores a data table indicating the operating ratios of the plant 1 for each of these combinations. Based on the calculation results of the performance calculation unit 302 and the data table, the performance improvement calculation unit 303 calculates the degree of performance improvement of the plant 1 compared to before the component was introduced, when the component was introduced and the plant 1 was operated at the ratios indicated in the data table.

[0063] Generally, simulations are performed by setting detailed, constantly changing plant conditions and performing transient analysis to improve performance when introducing new components. However, simulations are time-consuming and large-scale plants often suffer from difficulties such as simulation non-convergence.

[0064] However, the plant 1 shown in one embodiment of the present invention can quantitatively and easily determine the degree to which the plant performance is improved when new components are introduced compared to before the introduction of the new components by simulating multiple combinations of load and atmospheric temperature using the computing device 30 .

[0065] Furthermore, in the description of one embodiment of the present invention, the plant 1 includes the temperature sensor 20, and the temperature sensor 20 detects the temperature around the plant 1, and the computing device 30 obtains the temperature detected by the temperature sensor 20. However, the plant 1 in another embodiment of the present invention may not include the temperature sensor 20, and the computing device 30 may obtain information on the temperature around the plant 1 via the Internet, such as a weather forecast website.

[0066] In plant 1 according to one embodiment of the present invention, data tables TBL1 and TBL2 are described as having an ambient temperature range of 5°C and a load range of 10% of the maximum load. However, the ranges in data tables TBL1 and TBL2 are not limited to these.

[0067] In the plant 1 according to one embodiment of the present invention, it has been described that the new component may be one or more, and the computing device 30 calculates the performance of the plant 1 by changing parameters of all the new components.

[0068] Furthermore, the order of the processes in the embodiments of the present invention may be changed within the scope of performing appropriate processes.

[0069] The storage unit 301 and other storage devices in the embodiment of the present invention can be set anywhere within the range of appropriate information transmission and reception. In addition, the storage unit 301 and other storage devices can be multiple within the range of appropriate information transmission and reception to store data in a distributed manner.

[0070] While the embodiments of the present invention have been described, the aforementioned computing device 30 and other control devices may also include a computer system. Furthermore, the aforementioned processing procedures are stored in the form of a program on a computer-readable recording medium, and the computer reads and executes the program to perform the aforementioned processing. A specific example of a computer system is shown below.

[0071] Figure 6 This is a schematic block diagram showing the structure of a computer according to at least one embodiment.

[0072] like Figure 6 As shown, the computer 5 includes a CPU 6 , a main memory 7 , a storage 8 , and an interface 9 .

[0073] For example, the aforementioned computing device 30 and other control devices are each installed in the computer 5. Furthermore, the operations of the aforementioned processing units are stored in the form of programs in the memory 8. The CPU 6 reads the programs from the memory 8 and expands them in the main memory 7, thereby executing the aforementioned processing in accordance with the programs. Furthermore, the CPU 6 reserves storage areas corresponding to the aforementioned storage units in the main memory 7 in accordance with the programs.

[0074] Examples of storage 8 include an HDD (Hard Disk Drive), an SSD (Solid State Drive), a magnetic disk, a magneto-optical disk, a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), and semiconductor memory. Storage 8 can be an internal medium directly connected to the bus of computer 5 or an external medium connected to computer 5 via interface 9 or a communication line. Furthermore, if the program is distributed to computer 5 via a communication line, the computer 5 that receives the distribution can also expand the program into main memory 7 and execute the aforementioned processing. In at least one embodiment, storage 8 is a non-transitory, tangible storage medium.

[0075] Furthermore, the program may be a file that can realize a part of the aforementioned functions. Furthermore, the program may be a file that can realize the aforementioned functions by combining with a program already recorded in the computer system, that is, a so-called differential file (differential program).

[0076] While several embodiments of the present invention have been described, these embodiments are merely examples and do not limit the scope of the invention. Various additions, omissions, substitutions, and modifications may be made to these embodiments without departing from the spirit of the invention.

[0077] Industrial applicability

[0078] According to the calculation device, plant, calculation method, and program of the embodiment of the present invention, it is possible to quantitatively and easily determine to what extent the performance of the plant is improved when new components are introduced compared to before the introduction of the new components.

[0079] -Description of Reference Numerals-

[0080] 1･･･Complete set of equipment

[0081] 5. Computer

[0082] 6･･･CPU

[0083] 7･･･Main memory

[0084] 8･･･Memory

[0085] 9･･･Interface

[0086] 10･･･Power generation device

[0087] 20･･･Temperature sensor

[0088] 30･･･Computing device

[0089] 301 Storage Department

[0090] 302･･･Performance Computing Department

[0091] 303･･･Performance Improvement Computing Department

[0092] 304･･･Performance improvement result output section.

Claims

1. A computing device, characterized in that: have: a performance calculation unit for calculating the performance of the plant before the component is introduced and the performance of the plant after the component is introduced, for each combination of a plurality of loads in the plant and a plurality of atmospheric temperatures around the plant; a storage unit storing a data table indicating ratios of the operating times of the plants for the respective combinations; as well as a performance improvement calculation unit that calculates, based on the calculation result of the performance calculation unit and the data table, how much the performance of the plant is improved when the component is introduced and the plant is operated at the ratio shown in the data table, compared to before the introduction of the component; When a plurality of the components are introduced, the performance calculation unit calculates the performance of the plant using a coefficient indicating the degree of influence of a combination of components on the performance of the plant.

2. The computing device according to claim 1, wherein: The computing device comprises: A performance improvement result output unit outputs the calculation result of the performance improvement calculation unit.

3. The computing device according to claim 1 or 2, wherein: The performance of the plant includes at least one of fuel consumption of the plant, remaining life of the plant, and reduction in exhaust gas from the plant.

4. A complete set of equipment, characterized in that: have: The computing device according to any one of claims 1 to 3; and A power generation device supplies electric power corresponding to the load.

5. A calculation method, characterized in that: Include: calculating the performance of the plant before the component is introduced and the performance of the plant after the component is introduced for each combination of a plurality of loads in the plant and a plurality of atmospheric temperatures around the plant; storing a data table indicating the ratio of the operating time of the plants for the respective combinations; as well as Based on the calculated results of the performance of the plant and the data table, calculating to what extent the performance of the plant is improved when the component is introduced and the plant is operated at the ratio shown in the data table compared to before the introduction of the component, When a plurality of the components are introduced, the performance of the plant is calculated using a coefficient indicating the degree of influence of the combination of the components on the performance of the plant.

6. A program product comprising a program, The program product is characterized in that The program causes the computer to execute the following processing: calculating the performance of the plant before the component is introduced and the performance of the plant after the component is introduced for each combination of a plurality of loads in the plant and a plurality of atmospheric temperatures around the plant; storing a data table indicating the ratio of the operating time of the plants for the respective combinations; as well as Based on the calculated results of the performance of the plant and the data table, calculating to what extent the performance of the plant is improved when the component is introduced and the plant is operated at the ratio shown in the data table compared to before the introduction of the component, When a plurality of the components are introduced, the performance of the plant is calculated using a coefficient indicating the degree of influence of the combination of the components on the performance of the plant.

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