WO2019098077A1

WO2019098077A1 - Water quality diagnostic system, power generation plant, and water quality diagnostic method

Info

Publication number: WO2019098077A1
Application number: PCT/JP2018/041063
Authority: WO
Inventors: 貴行和田; 仙市椿▲崎▼; 翔下田
Original assignee: 三菱日立パワーシステムズ株式会社
Priority date: 2017-11-20
Filing date: 2018-11-05
Publication date: 2019-05-23
Also published as: CN111033253B; CN111033253A; KR102344805B1; PH12020500356A1; JP6878256B2; JP2019095232A; KR20200029555A

Abstract

The purpose of the present invention is to provide: a water quality diagnostic system in which degrees of water quality abnormality can be diagnosed more accurately and more uniformly; a power generation plant; and a water quality diagnostic method. This water quality diagnostic system disposed in a power generation plant is provided with: an electric conductivity measurement unit (3) that is disposed in a water circulation line (1) of a power generation plant and measures the electric conductivities of circulating water; a pH measurement unit (4) that is disposed in the water circulation line (1) and measures pH values of the circulating water; and a control device (5) that diagnoses degrees of water quality abnormality. The control device (5) is provided with: a storage unit that stores reference values based on correlations between the pH values and the electric conductivities in the water circulation line (1), a plurality of preset ranks that indicate the degrees of water quality abnormality in the water circulation line (1), and a range of deviations from the reference values corresponding to the plurality of ranks; and a rank determination unit that determines the ranks of measurement results, on the basis of the measurement results by the electric conductivity measurement unit (3) and the pH measurement unit (4), and on the basis of the range of deviations stored in the storage unit.

Description

Water quality diagnosis system, power generation plant, and water quality diagnosis method

The present invention relates to a water quality diagnosis system, a power plant, and a water quality diagnosis method.

In the power generation plant, in order to suppress corrosion of metal materials including iron, copper, etc. that constitute each structure of the water circulation system including boilers and turbines, piping, etc., the dissolved oxygen of water flowing in the water circulation system is kept as zero as possible. It is kept weakly alkaline using ammonia, etc. Water treatment to add ammonia and the like is performed when water is supplied from the condensate system in the water circulation system to the water supply system.

Since abnormalities in the water quality in the water circulation system (for example, a decrease in pH value etc.) cause corrosion of metal materials such as structures constituting the water circulation system, the water quality is regularly checked in the power generation plant. In general, water quality diagnosis of a power plant is conducted by the water quality inspector periodically reading the value of the meter and manually analyzing the read value to confirm comparison with the range of control reference values and changes over time Judgment of good or bad is done by doing. Furthermore, each measured value or each analyzed value may change due to contamination with impurities or foreign matter, and there may be a variation in each measured value or each analyzed value in which various factors overlap. For this reason, diagnosis of water quality abnormalities requires specialized knowledge, and individual judgment differences are included, making it difficult to uniformly judge water quality abnormalities.

Patent Document 1 describes that events (monitoring instrument data etc.) that occurred in the past are stored in a database system, and when a certain event occurs, reference is made to data stored in the database system.

JP 2003-288114 A

However, in order to judge the water quality in a power plant more accurately, it has been found that it is not sufficient to carry out water quality diagnosis separately for each measurement or analysis item as in the past. On the other hand, if the water quality abnormality is overlooked, corrosion etc. will occur in the water circulation system, which may cause major problems such as boiler evaporation pipe leakage and turbine performance deterioration, etc. It is desirable that it is possible to uniformly determine the tendency of analysis values to be abnormal or the like.

For example, the pH value and the electrical conductivity of water, which are separate measurement values, have a correlation based on the ammonia concentration. That is, even if the electric conductivity decreases due to the intentional operation for water quality adjustment, if the pH value also changes according to the correlation, there is no abnormality in the water quality (no harmful impurities are included) We came to discover the use of the water quality evaluation method that uses the characteristics. That is, if the pH value and the electrical conductivity do not deviate from the reference value based on the correlation calculated in advance, it is estimated that there is no contamination of other impurities and the like and there is no problem in the water quality. Therefore, in order to judge water quality more appropriately and uniformly, it came to discover that diagnosis of water quality abnormality can be performed in consideration of correlation of a measurement item.

Here, in order to uniformly recognize the tendency of the water quality abnormality etc., it is necessary to diagnose the degree of the water quality abnormality correctly. When diagnosing the water quality abnormality in consideration of the correlation of the measurement items, it is possible to recognize the water quality deterioration in advance by accurately and uniformly diagnosing the degree of the water quality abnormality. The impact can be minimized.

The present disclosure has been made in view of such circumstances, and provides a water quality diagnosis system, a power plant, and a water quality diagnosis method capable of diagnosing the degree of water quality abnormality more accurately and uniformly. With the goal.

In some embodiments of the present invention, an electric conductivity measurement unit provided in a water circulation system in a power plant and measuring electric conductivity of circulating water, and a pH value of the water provided in the water circulation system and circulated The controller comprises: a pH measuring unit for measuring; and a control device for diagnosing the degree of water quality abnormality, wherein the control device is a reference value based on the correlation between pH value and electric conductivity in the water circulation system, and water quality in the water circulation system A storage unit in which a plurality of preset ranks indicating the degree of abnormality and a deviation range from the reference value respectively corresponding to the plurality of ranks are stored; and the electric conductivity measurement unit and the pH measurement unit And a rank determination unit that determines a rank of the measurement result based on the measurement result and the deviation range stored in the storage unit.

According to the above configuration, the degree of water quality abnormality is determined based on the measurement result by the electrical conductivity measuring unit and the pH measuring unit based on the deviation range from the reference value based on the correlation between the pH value and the electrical conductivity. Therefore, it is possible to effectively judge the water quality abnormality which could not be accurately determined only by the pH value or the electrical conductivity alone. That is, even if there is little fluctuation in the pH value where confirmation is usually made with priority given to the standard range of water quality abnormality and no abnormality is recognized, by combining the fluctuation of electrical conductivity that is sensitive to water quality, The presence or absence of water quality abnormality can be judged effectively. Since the measurement results by the electrical conductivity measuring unit and the pH measuring unit are divided into a plurality of ranks indicating the degree of water quality abnormality, the water quality abnormality is accurately and uniformly judged without depending on the skill of the measurer. It becomes possible. Since the water quality abnormality can be accurately determined, the influence of the water quality deterioration on the entire power generation plant (for example, boiler evaporation tube leakage, turbine performance deterioration, etc.) can be effectively prevented.

In the water quality diagnosis system, the controller uses the determination result by the rank determination unit corresponding to each of a plurality of the measurement results, and the water circulation system according to a frequency distribution state of the plurality of ranks in the determination result. A comprehensive determination unit may be provided to comprehensively determine the degree of water quality abnormality in the above.

According to the configuration as described above, since the degree of water quality abnormality is comprehensively determined according to the frequency distribution state for a plurality of ranks, each of the conductivity measuring unit and the pH measuring unit determined in the predetermined period Even if each rank result to the measurement result is, for example, variation in each measurement result of the electrical resistivity due to the concentration difference of water flowing in the water circulation system (for example, ammonia concentration difference), within the error range from the frequency distribution of each rank If there is a large number of ranks that can be determined, a comprehensive judgment is made that there is no problem, not a serious abnormality, so that a comprehensive judgment with high accuracy can be made.

In the above water quality diagnosis system, the control device is configured in advance to a value different from the values of the electric conductivity measuring unit and the pH measuring unit used for the comprehensive determination according to the comprehensive determination result by the comprehensive determining unit. It is good also as providing the cause estimating part which presumes the cause of the above-mentioned general judgment result by judging whether it is set conditions or not.

According to the configuration as described above, it is determined whether or not the cause that can be the comprehensive determination result determined by the comprehensive determination unit satisfies a preset condition with respect to a value different from the value used for the comprehensive determination result. By doing this, it is possible to estimate automatically. For this reason, in particular, even when the comprehensive determination result indicates a high water quality abnormality, the cause can be accurately and quickly estimated, so that the plant abnormality can be detected early.

The water quality diagnosis system includes at least one acid electric conductivity measurement unit provided in the water circulation system and measuring acid electric conductivity of circulating water, and the cause estimation unit is a water quality abnormality having a high overall judgment result. It is determined whether the measurement result from the acid electrical conductivity measurement unit is equal to or greater than a preset threshold, and when it is a positive determination, seawater leakage is estimated as the cause of the overall determination result. You may do it.

According to the above configuration, even if the comprehensive determination result indicates high water quality abnormality, the cause estimation is based on whether the measurement result of the acid conductivity measuring unit is within a preset threshold or not. By being performed automatically, it is possible to quickly estimate whether the cause of the water quality abnormality is due to seawater leakage.

The water quality diagnosis system may further include a display unit that displays the comprehensive determination result and a cause corresponding to the comprehensive determination result estimated by the cause estimating unit.

According to the configuration as described above, the driver of the power generation plant can easily recognize the general determination result and the cause thereof, so that the abnormality of the plant can be promptly detected and dealt with.

The water quality diagnosis system includes a simulation device, and the control device includes a communication unit for transmitting to the simulation device the measurement result related to the cause and the water quality abnormality estimated for the comprehensive determination result, the simulation device The leakage leak amount and the leak time may be calculated based on the information acquired from the communication unit and the simulation model and / or the accumulated data in the past, and the leakage contamination range in the power plant may be derived. Good.

According to the above configuration, the operator of the power plant can easily recognize the contamination range. In the power plant, for the occurrence of water quality abnormality, it is possible to promptly propose the plan of measures such as future additional investigation contents and treatment contents, schedule, etc., and to easily restore the soundness of the power plant promptly and appropriately Become.

Some embodiments of the present invention are a power plant including a boiler, a steam turbine, a condenser, and the above water quality diagnosis system.

In some embodiments of the present invention, an electric conductivity measurement unit and a pH measurement unit provided in a water circulation system in a power plant, and a reference value based on a correlation between a pH value and electric conductivity in the water circulation system and the water circulation A water quality diagnosis system comprising a control unit having a storage unit in which a plurality of preset ranks indicating the degree of water quality abnormality in the system and a deviation range from the reference value corresponding to each of the plurality of ranks are stored. The method for diagnosing water quality according to claim 1, wherein an electric conductivity measuring step of measuring electric conductivity of circulating water, a pH measuring step of measuring pH value of circulating water, the electric conductivity measuring step and the pH measuring step And a rank determination step of determining the rank of the measurement result based on the measurement result obtained by the step and the deviation range stored in the storage unit.

According to the present invention, it is possible to diagnose the degree of the water quality abnormality more accurately and uniformly.

It is a figure which shows schematic structure of the water circulation system in the power generation plant provided with the water quality diagnostic system which concerns on 1st Embodiment. It is a functional block diagram showing the function with which the control device in the water quality diagnostic system concerning a 1st embodiment is provided. It is the figure which showed the information stored in the storage part in the water quality diagnosis system concerning a 1st embodiment. It is the figure which showed the correlation of pH value and electrical conductivity in the water quality diagnosis system which concerns on 1st Embodiment. It is the figure which showed the relationship of comprehensive judgment and rank in the water quality diagnosis system concerning a 1st embodiment. It is the figure which showed the flowchart of the rank determination process in the water quality diagnostic system which concerns on 1st Embodiment. It is a figure which shows schematic structure of the water circulation system in the power generation plant provided with the water quality diagnostic system which concerns on 2nd Embodiment. It is the functional block diagram which showed the function with which the control apparatus in the water quality diagnostic system concerning 2nd Embodiment is equipped. It is the figure which showed the cause and confirmation item of the water quality abnormality in the water quality diagnosis system which concerns on 2nd Embodiment. It is the figure which showed the example of a notification of the cause of the general diagnostic result and water quality abnormality in the water quality diagnosis system concerning a 2nd embodiment.

First Embodiment
Hereinafter, a water quality diagnosis system, a power plant, and a water quality diagnosis method according to some embodiments will be described with reference to the drawings.
FIG. 1 is a view showing a schematic configuration of a water circulation system 1 in a power plant provided with a water quality diagnosis system according to the first embodiment. As shown in FIG. 1, the water circulation system 1 according to the present embodiment mainly includes a steam system, a condensate system, a water supply system, an electrical conductivity measurement unit 3, a pH measurement unit 4, and a control device 5. It is provided as a configuration.

The steam system comprises a boiler 6 and a turbine 7 (steam turbine), and the condensate system comprises a condenser 8, a condensate pump 9, a condensate demineralizer 10, and a grand steam condenser 11. The water supply system is configured to include the low pressure heater 12, the deaerator 13, the water supply pump 14, and the high pressure heater 15. In the water circulation system 1 in the present embodiment, the boiler 6, the turbine 7, the condenser 8, the condensate pump 9, the condensate demineralizer 10, the grand steam condenser 11, the low pressure heater 12, the deaerator 13, the feed water pump 14, and the high pressure heater 15 are connected in order, and water (and steam) circulates through each device.

In the steam system, the feed water supplied from the water feed system is converted into steam by heat exchange in the boiler 6, and the turbine 7 is rotationally driven. Specifically, first, in the boiler 6, heat exchange with combustion heat of the fuel is performed to evaporate the high-pressure water supplied from the water supply system to generate high-temperature high-pressure steam. The boiler 6 is applicable also to any methods, such as a through flow method, a natural circulation method, and a forced circulation method. Then, the high temperature and high pressure steam is supplied to the turbine 7 to rotationally drive the turbine blades. In the turbine 7, the thermal energy of the steam supplied from the boiler 6 by the high pressure turbine or the low pressure turbine is converted into mechanical energy. Then, using a rotational torque generated by the action of steam on the turbine blades, a generator (not shown) is rotationally driven to generate electric power. The steam which has finished work in the turbine 7 is supplied to the condenser 8 in the condensate system.

In the water recovery system, the steam which has finished its work in the turbine 7 is condensed so that it can be supplied to the boiler 6 and the turbine 7 again. Specifically, in the condenser 8, cooling water is allowed to flow through a cooling pipe provided in the condenser 8, and heat exchange is performed between the exhaust steam from the turbine 7 and the cooling water flowing in the cooling pipe, Condensate and condense the exhaust steam. Then, the condensed water is sent to the condensed water demineralizer 10 by the condensed water pump 9. The condensed water demineralizer 10 purifies the water condensed by the condenser 8. The condensate contains a small amount of impurities such as metal ions and chlorine generated in the system, and these impurities may cause a failure such as corrosion of a heat transfer tube constituting the boiler 6. For this reason, in the condensate demineralizer 10, the desalting treatment is performed using an anion resin or a cation resin. The ground steam used for the shaft seal portion etc. of the turbine 7 is condensed by the ground steam condenser 11 and condensed. When the treatment of the condensate system is completed, the condensate is supplied to the water supply system as water supply.

In the water supply system, the water supply supplied from the condensate system is brought into a high temperature and high pressure state, and is supplied to the evaporation system of the boiler 6. The feed water supplied from the condensate system is heated to, for example, about 150 ° C. by the low pressure heater 12. The heated feed water is supplied to the deaerator 13 to remove non-condensed gas such as oxygen and carbon dioxide dissolved in the feed water. The deaerated feed water is pumped by the feed water pump 14, and the feed water in the high pressure state is further heated to, for example, about 250 ° C. by the high pressure heater 15, and is supplied to the boiler 6 without evaporation.

In the water circulation system 1, the above circulation is repeated. The configuration of the water circulation system 1 is not limited to the above configuration, and can be applied to any method.

The conductivity measuring unit 3 is provided in the water circulation system 1 and measures the conductivity of the circulating water. Specifically, the electrical conductivity measurement unit 3 is disposed upstream of the feed water flow with respect to the boiler 6. By measuring the electric conductivity of the feed water supplied to the boiler 6 by the electric conductivity measurement unit 3, it is possible to monitor the water treatment chemical concentration (for pH value adjustment) or the like of the feed water. Electrical conductivity (Specific
Conductivity: SC) may be written as SC separately from acid conductivity as described later. The electrical conductivity SC corresponds to the reciprocal of the electrical resistance [Ω · cm] possessed by the solution between the electrodes when the electrodes having a cross-sectional area of 1 cm ² face each other at a distance of 1 cm. That is, in the electrical conductivity measuring unit 3, the electrodes of a predetermined area are disposed apart by a predetermined distance, and a voltage is applied between the electrodes in a state where the water supply is flowing between them, so that the current flowing between the electrodes is It detects and calculates the electric conductivity.

The pH measurement unit 4 is provided in the water circulation system 1 and measures the pH value of the circulating water. Specifically, the pH measurement unit 4 is disposed upstream of the feed water flow with respect to the boiler 6. Usually, the water supply is maintained weakly alkaline (for example, about pH 9 to 10) in order to prevent corrosion of each device. By measuring the pH value of the feed water supplied to the boiler 6 by the pH measurement unit 4, it can be monitored whether the feed water is maintained weakly alkaline.

In the present embodiment, the electrical conductivity measurement unit 3 and the pH measurement unit 4 are disposed upstream of the feed water flow with respect to the boiler 6, but this is especially applied to the feed water supplied to the boiler 6 and the turbine 7. Water quality diagnosis is performed to suppress corrosion of the boiler 6 and the turbine 7. However, the arrangement positions of the electrical conductivity measurement unit 3 and the pH measurement unit 4 are not limited to the above positions, and can be appropriately changed and added.

The control device 5 diagnoses the degree of water quality abnormality using the measurement results of the electrical conductivity measurement unit 3 and the pH measurement unit 4.

The control device 5 includes, for example, a CPU (central processing unit) (not shown), a memory such as a random access memory (RAM), and a computer readable recording medium. The process of a series of processes for realizing various functions to be described later is recorded in the form of a program on a recording medium or the like, and the CPU reads this program to a RAM or the like to execute information processing and arithmetic processing. Thus, various functions described later are realized.

FIG. 2 is a functional block diagram showing the functions of the control device 5. As shown in FIG. 2, the control device 5 includes a storage unit 21, a rank determination unit 22, and a general determination unit 23.

The storage unit 21 respectively corresponds to a plurality of predetermined ranks indicating the degree of water quality abnormality in the water circulation system 1, a reference value based on the correlation between the pH value and the electric conductivity in the water circulation system 1, and a plurality of ranks. The deviation range from the reference value is stored. An example of the information stored in the storage unit 21 in the present embodiment is shown in FIG. In the present embodiment, the case where the rank is divided into, for example, five stages (ranks a to e) according to the difference range from the reference value in consideration of the measurement error of each measurement value will be described. Can be changed as appropriate.

The rank is a preset class for representing the degree of water quality abnormality, and is, for example, divided into rank a to rank e as shown in FIG. 3, and is determined for each measurement value. In the present embodiment, the rank a is the rank at which the degree of water quality abnormality is the lowest, and as shown in FIG. 3, indicates that the current operating state can be maintained without problems, for example, within the measurement error range. . Rank b is the second lowest rank in the degree of water quality abnormality and indicates that although it is within the standard, some outliers may be recognized. Rank c indicates that the degree of water quality abnormality is middle rank, and some abnormal values may be recognized, and it is necessary to check periodically. For example, public standards such as JIS standards Within the value, the upper limit level is acceptable. Rank d is the second highest rank of the degree of water quality abnormality, and indicates that serious outliers are recognized. Rank e is the rank where the degree of water quality abnormality is the highest, shows that many serious outliers are recognized, and it is necessary to take early measures, for example, a level that requires measures after unit shutdown It becomes. That is, when the diagnosis result of the water quality in the water circulation system 1 is a rank with high degree of water quality abnormality (especially, rank e), it indicates that an early response is necessary.

The reference value is calculated from the correlation between the pH value and the electrical conductivity based on the ammonia concentration that is added and managed for water treatment (to prevent corrosion) in the water circulation system 1. The correlation between pH value and conductivity can be expressed by the following approximate expression.

[Equation 1]
pH = 0.43 × ln (SC) +9.6 (1)

SC in Formula (1) has shown electrical conductivity [mS / m]. In equation (1), it is possible to calculate a pH value (theoretical value) with ammonia having the same concentration as the ammonia concentration estimated in a certain electric conductivity [mS / m]. The approximate line (reference value) of the correlation of pH value and electrical conductivity represented by Formula (1) is shown as a solid line in FIG. For example, in the formula (1), when the electric conductivity is 1 [mS / m], 9.6 is calculated as the pH value (theoretical value). This indicates that the ammonia concentration estimated from the electric conductivity of 1 [mS / m] and the ammonia concentration estimated from the pH 9.6 have the same value. That is, when the measurement result of the pH value and the electric conductivity is on the approximation line (reference value) represented by the equation (1) or in the vicinity of the measurement error range, the water in the water circulation system 1 is for water treatment It is estimated that there is very little contamination of impurities other than ammonia added to and there is no abnormality in the water quality. On the other hand, if the measurement results of the pH value and the electrical conductivity are largely separated from the approximate line (reference value) represented by the equation (1), some influence other than the ammonia added for water treatment , Indicates that the water quality is deteriorating. Some effects include, for example, seawater leakage (seawater mixing), organic matter mixing, and the like.

The deviation range from the reference value corresponding to each of the plurality of ranks is defined in accordance with the deviation state from the reference value of the correlation between the pH value and the electrical conductivity represented by the formula (1). For example, as shown in FIG. 3 and FIG. 4, the divergence range of rank a is set within the reference value ± 0.05. The divergence range of rank b is set within the reference value ± 0.1 (above the reference value ± 0.05). The divergence range of rank c is set within the reference value ± 0.15 (above the reference value ± 0.1). The divergence range of rank d is set within the reference value ± 0.2 (above the reference value ± 0.15). The divergence range of rank e is set to the reference value ± 0.2 or more. Thus, the measurement result of pH value and electrical conductivity can be uniformly associated with the degree of water quality abnormality by dividing and defining the range of deviation from the reference value in rank. The divergence range is not limited to the above, and can be changed as appropriate.

In FIG. 4, for example, a period from regular maintenance is divided into a period T1 (for example, 0 to 1.5 years), a period T2 (for example, 1.5 to 2.5 years), a period T3 (for example, 2.5 years) The graph shows an example of plotting the measurement results of the pH value and the conductivity obtained in each of the following periods. Although the measurement results of the pH value and the electrical conductivity in the period T1 are somewhat dispersed, there is no measurement result that is determined to be the rank e. However, as the aging progresses, the variation range of the pH value does not change so much, and the electrical conductivity significantly decreases. In period T2, the measurement result that is determined to be rank e increases, and in period T3, it is determined to be rank e Measurement results account for about half. In other words, the variation range of the pH value does not change much with the secular change, so the water quality abnormality that was overlooked only in the measurement of the pH value grasps the deviation state of the conductivity from the reference value. It can be confirmed that the water quality deviates from the reference value as it changes from T1 to T2 and T3. That is, in the example of FIG. 4, it is indicated that there is a possibility that an impurity that does not affect the pH value but affects only the electric conductivity may be mixed in the abnormality of the pH meter or the water circulation system. . As described above, by focusing on the deviation from the reference value of the correlation between the pH value and the electrical conductivity, it is possible to accurately determine the water quality abnormality which was difficult to grasp from the pH value.

As in the example of FIG. 4, even if the electrical conductivity is lowered, the pH value is also lowered, and if it is a separated state within the measurement error without much deviating from the reference value, ammonia added for water treatment The intentional operation of the added amount is that the amount of impurities other than ammonia is extremely small, and there is no problem with the water quality, or an abnormality in the ammonia addition equipment can be considered. For this reason, it is not possible to accurately grasp the water quality abnormality only by separately analyzing only the pH value or the electrical conductivity separately, and it is important to perform water quality diagnosis on the basis of the correlation between the pH value and the electrical conductivity. is there.

The rank determination unit 22 determines the rank of the measurement result based on the measurement result by the electrical conductivity measurement unit 3 and the pH measurement unit 4 and the divergence range stored in the storage unit 21. Specifically, the rank determination unit 22 acquires measurement results from the conductivity measurement unit 3 and the pH measurement unit 4 at predetermined intervals (for example, every hour), and stores the measurement results and the storage unit 21. Check against the range of divergence. Then, the rank corresponding to the divergence range in which the measurement result is included is determined. As described above, the degree of water quality abnormality is uniformly determined by making the degree of water quality abnormality correspond to the rank according to the deviation range with respect to the reference value indicating that the water quality is normal for each measurement result. be able to.

As the rank determination unit 22 acquires the measurement result by the electrical conductivity measurement unit 3 and the pH measurement unit 4 when the operation state is in the steady state so that the measurement result is not affected by the operation state of the power generation plant. It is also good. The steady state is, for example, a state in which a rated output with a plant output of 90% or more is performed. As described above, by defining the operating state of the power generation plant and using the measurement result in the steady state, the variation in the measurement result can be suppressed.

The comprehensive determination unit 23 uses the determination result by the rank determination unit 22 corresponding to each of the plurality of measurement results, and according to the frequency distribution state corresponding to the plurality of ranks in the determination result, the degree of water quality abnormality in the water circulation system 1 Make an overall decision. Specifically, the comprehensive determination unit 23 determines the rank determined for each measurement result by the electrical conductivity measurement unit 3 and the pH measurement unit 4 measured within a predetermined period (for example, one month from a predetermined date) A result is acquired, and a frequency distribution state is calculated for a plurality of acquired ranks (for example, rank a to rank e). As shown in FIG. 5, comprehensive judgments A to E are set in advance according to the frequency distribution criteria for a plurality of ranks (for example, rank a to rank e), and the degree of water quality abnormality is It can be comprehensively judged based on the state of the designated period. The frequency distribution reference of the rank in the comprehensive judgment A in this embodiment is, for example, that the rank a is 90% or more, and the ranks d and e are 0%, so that the current driving state can be maintained without problems. Is shown. For example, rank a and b are 80% or more, and ranks d and e are 0%, so that operation continuation is possible but some outliers are recognized. Indicates that they may be The frequency distribution reference of the rank in the comprehensive judgment D is, for example, a state in which the ranks a and b are 0%, the ranks d and e are 80% or more, and the rank e is less than 20%. The degree of abnormality is the second highest, and serious outliers may be observed, which requires preparation for maintenance. The rank frequency distribution standard in the comprehensive judgment E is, for example, that the rank e is 20% or more, the degree of water quality abnormality is the highest, many serious outliers are recognized, and early maintenance measures are necessary. Is shown. The comprehensive judgment C is a case other than the comprehensive judgments A, B, D, and E, and the degree of water quality abnormality is an intermediate rank, and some abnormal values may be recognized, and it is necessary to check periodically. It is shown that. The number of classes of integrated judgment and the frequency distribution reference in the integrated judgment unit 23 are not limited to the above described classes (A to E) and the frequency distribution reference, and can be changed as appropriate.

Next, the rank determination process by the above-described rank determination unit 22 will be described with reference to FIG. The flow shown in FIG. 6 is repeatedly executed in a predetermined control cycle (for example, every hour), and a rank result (for example, rank a ...) determined for each measurement result in units of one month from a predetermined date, for example. Rank e) is identified by the measurement date and time and stored.

First, the rank determination unit 22 acquires measurement results by the electrical conductivity measurement unit 3 and the pH measurement unit 4 (S101). Then, it is determined whether or not the acquired measurement result is within the divergence range of the rank a (within the reference value ± 0.05) (S102). If the acquired measurement result is within the divergence range of rank a (YES in S102), the measurement result is determined to be rank a (S103).

If the acquired measurement result is not within the divergence range of rank a (NO determination in S102), it is determined whether or not the acquired measurement result is within the divergence range of rank b (within reference value ± 0.1) (S104). If the acquired measurement result is within the divergence range of rank b (YES in S104), the measurement result is determined to be rank b (S105).

If the acquired measurement result is not within the divergence range of rank b (NO determination in S104), it is determined whether the acquired measurement result is within the divergence range of rank c (within reference value ± 0.15) (S106). If the acquired measurement result is within the divergence range of rank c (YES in S106), the measurement result is determined to be rank c (S107).

If the acquired measurement result is not within the divergence range of rank c (NO determination in S106), it is determined whether or not the acquired measurement result is within the divergence range of rank d (within reference value ± 0.2) (S108). If the acquired measurement result is within the divergence range of rank d (YES in S108), the measurement result is determined to be rank d (S109).

If the acquired measurement result is not within the divergence range of rank d (NO in S108), the measurement result is determined to be rank e (S110), and the process is ended. The above control is repeatedly performed in a predetermined control cycle, and a plurality of ranks (rank a to rank e) corresponding to the measurement result are identified by the measurement date and time and stored in the storage unit 21.

Then, the comprehensive determination unit 23 determines the rank (for example, rank a to rank e) determined for each measurement result by the electrical conductivity measurement unit 3 and the pH measurement unit 4 measured within a predetermined period (for example, one month). Is obtained from the storage unit 21 and comprehensive judgments (for example, A to E) are performed according to the frequency distribution state for the plurality of acquired ranks. The result of the comprehensive determination is displayed on a display or the like included in the power generation plant and notified to the operation of the power generation plant.

As described above, according to the water quality diagnosis system, the power generation plant, and the water quality diagnosis method according to the present embodiment, each measurement result by the electric conductivity measurement unit 3 and the pH measurement unit 4 is divided into pH value and electric conductivity. Since the degree of water quality abnormality is determined based on the deviation range from the reference value based on the correlation, water quality abnormality that could not be accurately determined only by the pH value or the electrical conductivity alone is effectively judged. be able to. Since the measurement results by the conductivity measuring unit 3 and the pH measuring unit 4 are divided into a plurality of ranks (for example, rank a to rank e) indicating the degree of water quality abnormality, accurate and accurate without depending on the skill of the measurer It becomes possible to judge the water quality abnormality uniformly. Since the water quality abnormality can be accurately determined, the influence of the water quality deterioration on the entire power generation plant (for example, boiler evaporation tube leakage, turbine performance deterioration, etc.) can be effectively prevented.

Since the degree of water quality abnormality is comprehensively judged (for example, A to E) according to the frequency distribution state for a plurality of ranks (for example, rank a to rank e), comprehensively based on the state of the designated period The presence or absence of an abnormality can be determined with high accuracy. For example, each rank result for each measurement result of the electrical conductivity measuring unit 3 and the pH measuring unit 4 determined in a predetermined period is, for example, the difference in electric resistivity by the concentration difference of water flowing in the water circulation system 1 (for example, ammonia concentration difference) Even if the measurement results vary, if the frequency distribution of rank a to rank e indicates that the frequency of rank a is high, comprehensive judgment is made that there is no problem and no serious abnormality. That is, it is possible to perform comprehensive judgment with high accuracy based on the frequency of each rank determined for each measurement value.

Second Embodiment
Next, a water quality diagnosis system, a power plant, and a water quality diagnosis method according to a second embodiment of the present invention will be described. The control device 5 in the first embodiment diagnoses the degree of water quality abnormality using the measurement results of the electrical conductivity measurement unit 3 and the pH measurement unit 4, but in the present embodiment, the control device 5 In addition to the process of the first embodiment, the cause of the water quality abnormality is estimated. Hereinafter, points of the water quality diagnosis system according to the present embodiment which are different from the first embodiment will be mainly described.

In the water quality diagnosis system according to the present embodiment, as shown in FIG. 7, the pH values of acid conductivity measuring unit 17 and boiler 6 water are measured as another measuring unit separately from the measuring unit of the first embodiment. A boiler water pH measurement unit 18, a chlorine concentration measurement unit 19, and a sodium concentration measurement unit 20 are provided. The control unit in the present embodiment is provided with a cause estimation unit 24 as shown in FIG.

The storage unit 21 stores the calibration history of the pH measurement unit 4, the cause of the estimated water quality abnormality, and a confirmation item for confirming the cause of the estimation. The calibration history of the pH measurement unit 4 is a calibration date and time when the pH measurement unit 4 was calibrated. In the present embodiment, for example, a part of the presumed cause of the water quality abnormality and the confirmation item for confirming the presumed cause are typically represented by a table as shown in FIG. In the present embodiment, it is assumed that the storage unit 21 stores, for example, causes and the like that are estimated in the case of comprehensive judgments D and E in which a comprehensive judgment is made that there is an abnormality in water quality.

If the water quality abnormality (overall judgment D or E) is determined and the average value of the measurement results by the pH measurement unit 4 is lower than the reference value, the pH measurement unit 4 is maintained as abnormal or weakly alkaline It shows that the water quality had deteriorated (it changed to acid tendency). For this reason, in the storage unit 21, there are respective causes (incorrect calibration of the pH measuring unit 4, seawater leakage, organic matter mixing, chlorine leakage) which are estimated as the causes of the abnormality of the pH measuring unit 4 or the water quality shifting to the acid tendency. It is stored. When the water quality abnormality (overall judgment D or E) is judged, and the average value of the measurement results by the pH measurement unit 4 is higher than the reference value, the pH measurement unit 4 is maintained as abnormal or weakly alkaline. It indicates that the water quality had deteriorated (further changed to an alkaline tendency). For this reason, the storage unit 21 stores the causes (incorrect calibration of the pH measuring unit 4 and sodium leakage) which are estimated as the causes of the abnormality of the pH measuring unit 4 or the water quality further shifting to the alkaline tendency. Among the above causes, the storage unit 21 stores confirmation items (C1 to C6) for estimating the more likely causes with respect to the respective causes.

The acid conductivity measuring unit 17 is installed at at least one of the outlet of the condenser 8, the inlet of the boiler 6, and the inlet of the turbine 7. The acid conductivity is passed through a strongly acidic cation exchange resin layer converted to the hydrogen ion type to remove volatile substances such as ammonium ions from the water flowing through the water circulation system 1, and the conductivity of the water after removal is calculated. I am measuring.
The boiler water pH measurement unit 18 is installed in the boiler 6 and measures the pH value of the boiler 6 water. In the case of a drum type boiler as an example of the boiler 6, the pH value of the boiler 6 water in the drum is measured.

At least one chlorine concentration measurement unit 19 is provided on the upstream side of the condensate demineralizer 10 in the condensate system and in the water supply system. The chlorine concentration measurement unit 19 measures the chlorine concentration of water supplied from the outside such as a pure water device (not shown) and flowing to the water circulation system 1.
At least one sodium concentration measurement unit 20 is provided on the upstream side of the condensate demineralizer 10 in the condensate system and in the water supply system. The sodium concentration measuring unit 20 measures the sodium concentration of the water flowing to the water circulation system 1 supplied from the outside such as a pure water device (not shown).

The cause estimation unit 24 automatically determines whether or not the condition different from the value used for the comprehensive determination result is satisfied in accordance with the comprehensive determination result by the comprehensive determination unit 23 and whether the condition is set in advance. Estimate the cause of the overall judgment result. Specifically, the cause estimation unit 24 reads the confirmation item for each cause of the water quality abnormality stored in the storage unit 21 and determines whether the condition described in the confirmation item is satisfied or not. The cause corresponding to the confirmation item is output as an estimation result.

Next, a specific example of the cause estimation process by the above-described cause estimation unit 24 will be described with reference to FIG. The cause and confirmation item shown in FIG. 9 are an example of a part, and the cause and confirmation item can be set as appropriate.
Although the specific process performed by the cause estimation unit 24 will be described below for each confirmation item, each cause estimation process is executed by sequential processing or parallel processing.

The average value of the measurement results by the pH measurement unit 4 measured within the predetermined period (for example, one month from the predetermined date) when the water quality abnormality (general judgment D or E) is judged and the comprehensive judgment is made is higher than the reference value When it is low, the cause estimation unit 24 reads out each of the confirmation items C1 to C4 from the storage unit 21 in order to estimate the cause of the water quality abnormality. Then, it is determined whether the condition described in each confirmation item is satisfied for a value different from the value used for the comprehensive determination result, and the cause is estimated.

When reading the confirmation item C1 from the storage unit 21, the cause estimation unit 24 refers to the calibration history of the pH measurement unit 4 and determines whether or not the calibration has been performed within a predetermined period (for example, one month). . Then, if it is determined that the calibration has not been performed within a predetermined period, the cause of the water quality abnormality when the deterioration state of the pH measurement unit 4 is confirmed by comparing the value with the hand analysis, etc. As, the cause of the calibration failure of the pH measurement unit 4 is estimated.

When the confirmation item C2 is read from the storage unit 21, the cause estimation unit 24 acquires the measurement result of the acid conductivity measurement unit 17 and determines whether the measurement result is within a preset threshold. If it is determined that the measurement result of the acid conductivity measuring unit 17 is not within the preset threshold value, it is assumed that seawater infiltrates and a trace amount of hydrogen chloride (HCl) is generated. Seawater leakage is estimated as the cause. The threshold value in the confirmation item C2 is set as the acid conductivity in which the salt concentration allowed for water flowing in the water circulation system 1 is considered. In order to confirm the occurrence location of seawater leakage, it is preferable that the acid conductivity measuring unit 17 be installed at the outlet of the condenser 8, near the inlet of the boiler 6, and near the inlet of the turbine 7 and compare the measurement results.

When reading the confirmation item C3 from the storage unit 21, the cause estimation unit 24 acquires the measurement results of the pH measurement unit 4 and the boiler water pH measurement unit 18, and the measurement result of the pH measurement unit 4 and the boiler water pH measurement unit It is determined whether or not the difference from the 18 measurement results is within a preset threshold value. Then, when it is determined that the difference between the measurement result of the pH measurement unit 4 and the measurement result of the boiler water pH measurement unit 18 is not within the preset threshold, organic substance contamination is estimated as the cause of the water quality abnormality. In the water circulation system 1, when organic matter is mixed from industrial water or the like supplied from the outside, there is a high possibility that the organic matter is decomposed due to temperature rise and a trace amount of acid is generated. For this reason, for example, due to the mixing of organic substances by comparing local differences using the pH values of the pH measuring unit 4 provided on the upstream side of the boiler 6 and the boiler water pH measuring unit 18 provided in the boiler 6 Acid generation can be detected. The threshold value in the confirmation item C3 is set as a pH value corresponding to the amount of generated acid when it is assumed that an acid is generated from an organic substance due to a temperature rise.

When the confirmation item C4 is read from the storage unit 21, the cause estimation unit 24 acquires the measurement result of the chlorine concentration measurement unit 19, and determines whether the measurement result of the chlorine concentration measurement unit 19 is within a preset threshold. judge. Then, when it is determined that the measurement result of the chlorine concentration measurement unit 19 is not within the preset threshold value, a slight amount of chlorine leakage from a pure water device (not shown) or the like is estimated as the cause of the water quality abnormality. . Confirm the trace chlorine concentration from ion chromatography etc. and determine the cause. The threshold value in the confirmation item C3 is set as the concentration of chlorine that is allowed for the water flowing through the water circulation system 1.

On the other hand, the average value of the measurement results by the pH measurement unit 4 measured within the predetermined period (for example, one month from the predetermined date) in which the water quality abnormality (general judgment D or E) was judged and the comprehensive judgment was made When it is higher than the value, the cause estimation unit 24 reads out each confirmation item C5-C6 from the storage unit 21 in order to estimate the cause of the water quality abnormality. Then, it is determined whether or not the condition described in each confirmation item is satisfied, and the cause is estimated.

When reading the confirmation item C5 from the storage unit 21, the cause estimation unit 24 refers to the calibration history of the pH measurement unit 4 and determines whether or not the calibration has been performed within a predetermined period (for example, one month). Then, if it is determined that the calibration has not been performed within a predetermined period, the cause of the water quality abnormality when the deterioration state of the pH measurement unit 4 is confirmed by comparing the value with the hand analysis, etc. As, the calibration failure of the pH measurement unit 4 and the cause are estimated. The confirmation item C5 is the same as the confirmation item C1.

When reading the confirmation item C6 from the storage unit 21, the cause estimation unit 24 acquires the measurement result of the sodium concentration measurement unit 20, and determines whether the measurement result of the sodium concentration measurement unit 20 is within a preset threshold. judge. Then, when it is determined that the measurement result of the sodium concentration measurement unit 20 is not within the preset threshold value, a slight amount of sodium leakage from a pure water device (not shown) or the like is estimated as the cause of the water quality abnormality. . Check the concentration of a small amount of sodium component from ion chromatography etc. and determine the cause. The threshold value in the confirmation item C6 is set as the concentration of sodium acceptable to the water flowing through the water circulation system 1.

Thus, in the cause estimating unit 24, when the integrated determination D or E indicating water quality abnormality is determined, a cause different from the value used for the integrated determination result is estimated from the storage unit 21 and The confirmation item is read out, and the probable cause is estimated based on the conditions described in each confirmation item. The estimated cause is displayed on a display or the like included in the power plant, and the operator of the power plant is notified. This makes it possible to estimate the cause accurately and quickly, so that plant abnormalities can be detected early.

When the operator of the power generation plant is notified of the comprehensive determination result and the cause thereof, for example, a map image as shown in FIG. 10 may be displayed on the display. In the map shown in FIG. 10, the horizontal axis indicates the comprehensive determination result, and the vertical axis indicates the acid conductivity. The upper right on the map indicates that the level of attention (impact) of each water quality anomaly is high. The cause of the water quality abnormality stored in the storage unit 21 is arranged on the map according to a preset threshold value. Then, according to the comprehensive judgment result and the cause estimation result, the visual attention level and the cause can be notified easily and quickly by indicating the current value of the measurement value corresponding to the cause of each water quality abnormality with a 印 mark or the like. it can. In the example of FIG. 10, the comprehensive determination E is determined, and the measurement value when seawater leakage is estimated as the cause is shown as the current value. Each cause, attention level, etc. can be changed suitably.

The comprehensive judgment result and the cause estimated for the general judgment result, the map shown in FIG. 10, the measurement result related to the water quality abnormality, the operation state of the power generation plant, etc. are for example by the communication device (not shown) via the Internet etc. It may be transmitted to a computer (simulation apparatus) installed at a remote control center or the like and displayed. The computer may be provided in a power plant. The measurement results related to the water quality abnormality are, for example, each measurement unit (electrical conductivity measurement unit 3, pH measurement unit 4, acid conductivity measurement unit 17, boiler water pH measurement unit 18, chlorine concentration measurement unit 19, sodium It is a measurement result obtained from the concentration measurement unit 20 or the like. In the computer, for example, a simulation model and / or data accumulated from the past according to the information acquired from the communication device (for example, the overall determination result, the cause estimated for the overall determination result, the operating state of the power plant, etc.) The leakage leak amount and the leak time may be calculated using (the measurement results of the electrical conductivity measuring unit 3 and the pH measuring unit 4) or the like, the seawater leakage contamination range in the power plant may be calculated, and the map may be displayed. The simulation model is a virtual model of a power generation plant, and it is possible to virtually operate the virtual model on a computer according to each parameter (for example, measurement results of the electrical conductivity measurement unit 3 and the like). The data accumulated from the past refers to each measurement data (data in which the measurement result of each measurement unit such as the electric conductivity measurement unit 3 and leakage leak etc. is associated) when leakage leak actually occurs in the power generation plant is there. A map of the seawater leakage contamination range in this power generation plant is transmitted to the control room of the power generation plant by a communication device (not shown) and the operator of the power generation plant is easily polluted by visualizing and showing the seawater leakage contamination range. The range can be recognized. In the power plant, for the occurrence of water quality abnormality, it is possible to promptly propose the plan of measures such as future additional investigation contents and treatment contents, schedule, etc., and to easily restore the soundness of the power plant promptly and appropriately Become.

As described above, according to the water quality diagnosis system, the power generation plant, and the water quality diagnosis method according to the present embodiment, it is possible to automatically estimate the cause that can be the comprehensive determination result determined by the comprehensive determination unit 23 Become. For this reason, in particular, even in the case where the comprehensive determination result indicates high water quality abnormality, it is possible to accurately and quickly estimate the cause. Since the cause of the water quality abnormality can be recognized quickly, it can be expected to take an early response.

The present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. It is also possible to combine each embodiment.

1: Water circulation system 3: Electric conductivity measurement part 4: pH measurement part 5: Control device 6: Boiler 7: Turbine 8: Condenser 9: Condenser pump 10: Condensate water desalination apparatus 11: Grand steam condenser 12: low pressure heater 13: deaerator 14: feed water pump 15: high pressure heater 17: acid conductivity measuring unit 18: boiler water pH measuring unit 19: chlorine concentration measuring unit 20: sodium concentration measuring unit 21: storage unit 22: Rank determination unit 23: General determination unit 24: Cause estimation unit

Claims

An electric conductivity measurement unit provided in a water circulation system in a power plant and measuring electric conductivity of circulating water;
A pH measuring unit provided in the water circulation system and measuring a pH value of the circulating water;
A controller for diagnosing the degree of water quality abnormality;
Equipped with
The controller is
From the reference value based on the correlation between pH value and electric conductivity in the water circulation system, a plurality of preset ranks indicating the degree of water quality abnormality in the water circulation system, and the reference values respectively corresponding to the plurality of ranks A storage unit in which the divergence range of
A rank determination unit that determines a rank of the measurement result based on the measurement result by the electrical conductivity measurement unit and the pH measurement unit, and the divergence range stored in the storage unit;
Water quality diagnostic system equipped with
The control device uses the determination result by the rank determination unit corresponding to each of the plurality of measurement results, and the degree of water quality abnormality in the water circulation system according to the frequency distribution state of the plurality of ranks in the determination result The water quality diagnosis system according to claim 1, further comprising a comprehensive determination unit that determines comprehensively.
The control device satisfies a preset condition for a value different from the values of the electric conductivity measurement unit and the pH measurement unit used for the comprehensive determination according to the comprehensive determination result by the comprehensive determination unit. The water quality diagnosis system according to claim 2, further comprising: a cause estimation unit configured to estimate a cause of the comprehensive determination result by determining whether or not it is.
The water circulation system includes at least one acid electric conductivity measurement unit provided in the water circulation system and measuring acid electric conductivity of the circulating water,
The said cause estimation part determines whether the measurement result from the said acid electrical conductivity measurement part is more than the preset threshold value, when the said general determination result shows high water quality abnormality, It is affirmation determination The water quality diagnosis system according to claim 3, wherein seawater leakage is estimated as a cause of the comprehensive determination result.
The water quality diagnosis system according to claim 3, further comprising a display unit that displays the comprehensive determination result and a cause corresponding to the comprehensive determination result estimated by the cause estimation unit.
Equipped with simulation equipment,
The control device includes a communication unit that transmits, to the simulation device, a measurement result related to the cause and water quality abnormality estimated for the comprehensive determination result.
The simulation apparatus calculates a leakage leakage amount and a leakage time based on the information acquired from the communication unit and the simulation model and / or accumulated data in the past, and derives a leakage contamination range in the power generation plant. The water quality diagnosis system according to claim 4 or 5.
A boiler,
With a steam turbine,
With a condenser,
The water quality diagnosis system according to any one of claims 1 to 6,
Power plant equipped with.
Electric conductivity measurement unit and pH measurement unit provided in the water circulation system in the power generation plant, and a reference value based on the correlation between pH value and electric conductivity in the water circulation system, and a preset value indicating the degree of water quality abnormality in the water circulation system A control device having a storage unit in which the plurality of ranks and the deviation range from the reference value respectively corresponding to the plurality of ranks are stored;
An electrical conductivity measurement step of measuring the electrical conductivity of circulating water;
PH measurement process which measures pH value of circulating water,
A rank determination step of determining a rank of the measurement result based on the measurement result of the electric conductivity measurement step and the pH measurement step, and the deviation range stored in the storage unit;
Water quality diagnostic method with.