JP2971213B2 - Abnormality detector for pH meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting an abnormality in a pH meter, and more particularly, to a pH meter for measuring the pH of water circulating in a piping system in a thermal power plant. Related to an abnormality detection device.

[0002]

2. Description of the Related Art Conventionally, in a thermal power plant, steam is ejected from a turbine connected to a generator to rotate the turbine, and the steam that has completed the work of rotating the turbine is cooled, returned to water, and returned. The dewatered water is passed through an ion exchange resin to remove ionic substances and degassed.Clean water from which ionic substances and dissolved oxygen have been removed is heated again by a boiler to produce steam, and this steam is ejected to a turbine again. , Has a water circulation system. Here, the cooling of the steam is usually performed with seawater.

What is important in the water circulation system in such a thermal power plant is the management of the circulating water quality. That is, if the quality of the circulating water is poor, corrosion of the boiler, turbine, piping, and the like occurs, which causes a disadvantage that the life of the water circulation system is shortened.

In order to control the quality of water in a water circulating system in a conventional power plant, first, conductivity of water, pH of water, dissolved oxygen concentration in water, hydrazine concentration, dissolved hydrogen concentration in water, and total iron concentration in water. ,
Control of water turbidity, chlorine concentration in water, and sodium ion concentration in water can be mentioned.

[0005] Such water quality control is particularly necessary not only during operation of the thermal power plant, but also when the thermal power plant is once stopped and then restarted.
During the operation of the thermal power plant, if it is discovered that the quality of the circulating water has deteriorated, it is necessary to quickly pursue the cause of the quality deterioration of the circulating water in order to quickly prevent corrosion of piping and boilers, etc. When restarting the operation of the thermal power plant that was stopped, the water circulation system was replaced with normal circulating water, and the circulating system that may have been generated by the stagnant water remaining in the circulation system during the stoppage of the operation was considered. This is because it is necessary to quickly find the faulty part inside and repair it.

[0006] The conductivity of the water is managed to satisfy such a need, for example, to monitor the possibility of seawater used for cooling the steam entering the water circulation system. If seawater enters the circulating water, the concentration of ionic substances such as chloride ions should increase, and if the concentration of the ionic substances increases, the conductivity of the circulating water should increase. In addition, the pH of water described below
This is because ammonium ions can be detected in conjunction with the monitoring of.

The pH of the water is monitored by measuring the pH of the circulating water.
Monitoring the dissolved oxygen concentration in water is to prevent corrosion of piping, boilers or turbines, etc. The monitoring may be to monitor the presence of dissolved oxygen in the circulating water, such as by checking the degree of consumption of hydrazine added for deoxygenation from the circulating water. Monitoring the concentration of dissolved hydrogen in water can be used to diagnose abnormal conditions such as the occurrence of corrosion in turbines. Monitoring the total iron concentration in the water and the turbidity of the water can detect the presence or absence of scale. Monitoring of chlorine concentration in water and sodium ion concentration in water can check for contamination of seawater.

Means for monitoring the pH of water among the above-mentioned monitoring items is to periodically check a large number of pH meters installed in a condensing system or a water supply system of a conventional piping system, and to periodically check the pH. Monitoring of the pH of water and judging the presence or absence of an abnormality in each pH meter are performed from the collected data.

[0009]

However, it is not possible to judge whether the indicated value of each pH meter accurately indicates the actual pH value of the water flowing through the piping system based on the above-mentioned collected data. It is difficult to do so, and in the prior art, a pH value check by manual analysis using a standard solution is actually used together.

It is also extremely important to properly maintain the pH values of the condensing system and the water supply system of the thermal power plant from the viewpoint of preventing corrosion of the piping system of the thermal power plant. If a thermal power plant is operated for a long time by believing in an incorrect pH value due to the above, there is a problem that the corrosion of the piping system proceeds and a serious accident is caused.

The present invention has been completed based on the above circumstances. That is, an object of the present invention is to provide a pH meter abnormality detection device capable of always and automatically diagnosing abnormality of a pH meter installed in a piping system in a thermal power plant. It is.

[0012]

The present invention for solving the above-mentioned problems comprises a pH meter for measuring the pH value of water circulating in a piping system in a thermal power plant,
A conductivity meter for measuring the conductivity of water at the same measurement position as the meter, a pH conversion means for obtaining a converted pH value at the measurement position based on the conductivity measured by the conductivity meter, The calculated converted pH value and the pH measured by the pH meter
An abnormality detecting device for a pH meter, comprising: an abnormality determining unit that compares a value with an abnormality to determine whether the pH meter has an abnormality; and a display unit that displays a determination result of the abnormality determining unit.

[0013]

The operation of the above-described pH abnormality detection device will be described below.

The pH meter in the pH meter abnormality detecting device measures the pH value of water circulating in a piping system in a thermal power plant, for example, and sends out the measurement result. The conductivity meter measures the conductivity of water at the same measurement position as the pH meter, and sends out the measurement result.

The pH conversion means calculates a converted pH value at the measurement position based on the conductivity measured by the conductivity meter,
The converted pH value is sent out. The abnormality determining means compares the converted pH value obtained by the pH converting means with the pH value measured by the pH meter, determines whether or not the pH meter is abnormal, and sends the determination result to a display means. Thus, the presence or absence of an abnormality in the pH meter installed in the piping system can always be automatically and accurately determined.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a thermal power plant including an apparatus according to an embodiment of the present invention will be described in detail.

FIG. 1 shows an outline of the thermal power plant.

(A) Water Circulation System in Thermal Power Plant-Configuration of Water Circulation System- As shown in FIG. 1, the condensing system condenses the steam having completed its work in a cooling pipe ST that conducts seawater to form a liquid. Water was conveyed by a steam condenser C for converting water, a condensed water storage tank HW for storing condensed water, a condensate pump CP for supplying water discharged from the condensed water storage tank HW, and a condensate pump CP. A condensate demineralizer DEMI for removing ionic substances in water with an ion exchange resin, a condensate booster pump CBP for supplying water (desalinated water) from which ionic substances have been removed, and a low pressure for heating the supplied water. It has a heater LPHTR, a deaerator DEA for removing oxygen from the heated water heated by the low-pressure heater LPHTR, and a pipe connecting these in series. Note that distilled water is supplied to the condensed water storage tank HW from the makeup water tank T through a pipe.

[0019] In this condensate system, first a valve V ₁ to the branch pipe branched from the pipe connecting the condensate pump CP and condensate demineralizer DEMI, condensate pump CP and condensate desalination A second valve V ₂ is provided on a side pipe that bypasses the condensate demineralization apparatus DEMI from a pipe connecting the apparatus DEMI, and a condensate booster pump CBP and a low-pressure heater LP.
Third valve V ₃ is provided on the side pipe back to the condensate storage tank HW from the pipe coupling the HTR, fourth valve V ₄ is provided in the pipe branched from the degasser DEA, degasser DE
Fifth valve V ₅ is provided on the side pipe returning from the pipe coupling the A and the high-pressure heater HPHTR to condensed water reservoir HW.

An ammonia injection pipe (not shown) for injecting ammonia into the water circulation system and a hydrazine injection for injecting hydrazine into the water circulation system are connected to a pipe connecting the condensate demineralizer DEMI and the condensate booster pump CBP. A tube (not shown) is connected. The water supply system includes a high-pressure water supply pump BFP that produces high-pressure water by sending water discharged from the deaeration device DEA to a pipe whose diameter is reduced, and a high-pressure water that is supplied from the high-pressure water supply pump BFP. High-pressure heater HPHTR, high-pressure water preheated by the high-pressure heater HPHTR, a economizer ECO that preheats the hot water to a higher temperature, and high-pressure high-temperature water preheated to a higher temperature by the economizer ECO to high-pressure steam And a water separator WS that separates high-pressure steam converted into steam by the water wall WW and high-pressure high-temperature water not converted into steam.

In this water supply system, a condensed water storage tank HW is connected to a pipe connecting the economizer ECO and the high-pressure heater HPTTR.
A sixth valve V ₆ is attached to the side pipe returning to
Seventh valve V ₇ is attached to the branch pipe branched from a pipe connecting the valve V ₆ and the high-pressure heater HPHTR, eighth valve V ₈ is attached to the side tube back to the condensate storage tank HW from Wota over separator WS, the branch pipe that branches from the eighth pipe connecting the valve V ₈ and Wota over wall WW 9
Valve V ₉ is provided.

The steam system includes a super heater S for further increasing the temperature of the high-pressure steam converted by the water wall WW.
P, a high-pressure turbine HP for injecting high-pressure steam raised to a high temperature by the super heater SP to drive the generator, and a reheater R for reheating the steam passing through the high-pressure turbine HP.
H, an intermediate-pressure turbine IP that ejects high-pressure steam reheated by the reheater RH to drive the generator, and an intermediate-pressure turbine I
And a low-pressure turbine LP that ejects high-pressure steam via the P to drive the generator.

-Movement of Water During Plant Operation in Water Circulation System-In the water circulation system configured as described above, water circulates during operation of the thermal power plant as follows.

That is, the steam that has completed the work in the low-pressure turbine LP is supplied to the steam condenser C, where the steam is cooled by the cooling pipe ST, condensed and converted into water as a liquid. The condensed water obtained by converting the steam into water is temporarily stored in the condensed water storage tank HW, and is condensed from the condensed water storage tank HW by the condensate pump CP to the condensate desalination unit DEMI.
Water is sent to The condensed water is ion-exchanged by the condensing demineralizer DEMI, and the purified water from which the ionic substances have been removed is sent to the low-pressure heater LPHTR by the condensing booster pump CBP. The purified water is preheated by the low pressure heater LPHTR and sent to the deaerator DEA. In the deaerator DEA, purified water is deaerated, and mainly oxygen gas is removed.

The degassed purified water from which oxygen gas has been mainly removed is sent to the high-pressure heater HPHTR as high-pressure water by the high-pressure water pump BFP. In the high-pressure heater HPHTR, the deaerated purified water is preheated. The preheated degassed purified water is preheated to a higher temperature in the economizer ECO.
The preheated high-pressure degassed purified water is converted into high-temperature and high-pressure steam in the water wall WW.

The high-temperature and high-pressure steam converted by the water wall WW is further heated to a high temperature by the super heater SP, and the obtained high-temperature and high-pressure steam is jetted to the high-pressure turbine HP, passes through the high-pressure turbine HP, and has a low temperature. The lowered high-pressure steam is heated again to a high temperature by the reheater RH, and thereafter supplied to the intermediate-pressure turbine IP to drive the intermediate-pressure turbine IP. The steam having passed through the intermediate pressure turbine IP is supplied to the low pressure turbine LP. The generator is driven by these high-pressure turbine HP, medium-pressure turbine IP, and low-pressure turbine LP, and outputs electric power. The steam that has passed through the low-pressure turbine LP is returned to the steam condenser C, and repeats the same cycle as described above.

-Water movement at start-up of thermal power plant-Thermal power plant performs periodic inspections,
When an abnormal condition occurs, the operation is stopped. While the operation is stopped, much circulating water still remains in the main piping of the water circulation system. The quality of the residual water deteriorates in accordance with the length of the shutdown period of the thermal power plant. Alternatively, dirt is generated in the piping. Therefore, when restarting the operation of the thermal power plant, it is necessary to clean the water circulation system.

The washing operation is performed as follows. That is, the addition to releasing the first valve V ₁ 2
The valve V ₂ and the inlet of the condensate demineralizer DEMI are closed, and make-up water is supplied from the make-up water tank T into the steam condenser C. The makeup water is stored from the steam condenser C in the condensed water storage tank HW. Then, by driving the condensate pump CP, discharged outside the makeup water from the first valve V _1. The makeup water supplied from the makeup water tank T is passed through the steam condenser C, the condensation water storage tank HW, and the condensate pump CP to the first
By discharged from valve V ₁ to the outside of the system, so that the steam condenser C, the condensed water storage tank HW, is a condensate pump CP and the piping connecting them are cleaned with make-up water.

After performing the washing operation for a certain period of time,
The thereby releasing the valve V ₂ and the third valve V ₃ 1
Closing the inlet valve V ₁ and the low-pressure heater LPHTR, condensed water reservoir HW, condensate pump CP, the second valve V
Side tube having a _2, a circulating system formed by the side tube having a condensate booster pump CBP and the third valve V _3, circulating water. After going over circulation predetermined time, the second closes the valve V ₂ with opening the inlet of the condensate demineralizer DEMI, condensed water reservoir HW, condensate pump CP, condensate demineralizer DEMI, condensate Water booster pump CBP and 3rd
Circulating the circulation system formed by the side tube having a valve V _3. At this time, the water circulated by the condensate demineralizer DEMI becomes desalinated water and is washed.

Thereafter, by repeating the same operation,
Low pressure heater LPHTR, deaerator DEA, high pressure heater H
The PHTR, the economizer ECO, the water wall WW, the water separator WS, and the piping connecting them are cleaned.

(B) Water Quality Monitoring System The water quality in the water circulation system described above is monitored by a water quality monitoring system described below. Then, the monitoring result is displayed in real time.

-Configuration of Water Quality Monitoring System- FIG. 2 shows a configuration of a water quality monitoring system.

As shown in FIG. 2, the water quality monitoring system comprises a process signal generating means 1 in the water circulation system,
An AD converter 2 for converting a voltage value signal output from the process signal generating means 1 into a digital signal; and a water quality detecting means installed in a water circulation system for detecting water quality and outputting the same as voltage value data. And AD converting the voltage value data output from the water quality detecting means 3 into a digital value.
A converter 2, a data recording unit 4 for converting data from the water quality detecting means 3 and the process signal generating means 1 through the AD converter 2 into engineering value data, a process signal generating means 1, a water quality detecting means 3, and Abnormal alarm generating means 7
In addition to displaying the water circulation system graphically based on the data output from, the water quality data and process data at each water quality detection site are collectively displayed, and the data is processed so that the water circulation site in the water circulation system is displayed in, for example, light blue. Data output from the process state diagram creating means 5, the process signal generating means 1, and the water quality detecting means 3 are input, and the data is processed so that the change of the designated water quality item is graphically displayed in time sequence. The data output from the trend diagram creating means 6, the process signal generating means 1, and the water quality detecting means 3 are input, and regarding the abnormal water quality, the item of the abnormal water quality, its occurrence location, date and time of occurrence, and the content of the abnormality And the like, an abnormal alarm generating means 7 for processing data, a process signal generating means 1, and a water quality detecting means 3 And outputs the past water quality data from the first storage means 9 to be described later, diagnoses the diagnostic information for supporting the operation of the thermal power plant and diagnoses the cause of the abnormal water quality. Diagnostic processing means 8 for processing data so as to display the contents; first storage means 9 for storing real-time data and past data output from the process signal generating means 1 and the water quality detecting means 3; Second storage for storing each data output from the process state diagram creating unit 5, the trend diagram creating unit 6, the abnormal alarm generating unit 7 and the diagnostic processing unit 8 at addresses corresponding to each pixel of the display screen divided into four. Means 10;
The image data is read from the second storage means and displayed on the display means 12.
And the image data output from the display driving means 11 and the water supply system, the steam system and the condensate system in the thermal power plant based on the data output from the process state diagram creating means 5. Water quality history relating to the history of water quality in each part of the circulatory system based on the process state diagram for displaying the water quality information on the current water quality in each part in the circulating system of the water and the data output from the trend diagram creating means 6 Based on a trend chart displaying information and data output from the abnormality alarm generating means 7, diagnose the cause of an abnormal state based on driving support information on water quality and data output from the diagnostic processing means 8,
A display means 12 for independently displaying water quality information on water quality management in four areas on the screen, a control operation means 13 for controlling and calculating each of the above means, an operation command to the control operation means 13 or a predetermined operation Input means 1 for inputting data
4 is provided.

In this embodiment, the display means 1
2, a CRT screen is adopted, a process state is displayed in a substantially upper half area on the left side of the CRT screen, a trend diagram as water quality history information is displayed in a substantially upper half on the right side of the CRT screen, and a left side of the CRT screen is displayed. The diagnostic content as driving support information is displayed in a substantially lower half area, and the diagnostic content as water quality information is displayed in a substantially lower half area on the right side of the CRT screen.

-Each means in the water quality monitoring system-Each of the above means will be described in more detail.

(A) Process signal generating means 1 The process signal generating means 1 includes a condensing system flow rate measuring device for measuring a water flow rate at an inlet of a condensing booster pump CBP in a water circulating system, and a water flow rate at an ECO inlet of a economizer. And a water supply flow rate measuring device for measuring the flow rate. The water flow rate measured by the condensing system flow measuring device and the water supply system flow measuring device is output to the AD converter as voltage value data.

(B) Water quality detection means 3 The detection items by the water quality detection means 3 include water conductivity, water pH, dissolved oxygen concentration in water, hydrazine concentration, dissolved hydrogen concentration in water, and total iron concentration in water. Turbidity, chlorine concentration in water, and sodium ion concentration in water.

The water quality detecting means 3 for measuring the conductivity of water is
It is a conductivity meter. By monitoring this conductivity, it is possible to check whether seawater, which is cooling water, has entered the circulation system, and to monitor the ammonia concentration in the water in the circulation system. In the water circulation system shown in FIG. 1, the electric conductivity is determined by the condensate pump CP
Outlet, condensate desalination unit DEMI outlet, low pressure heater LP
Inside the HTR, DEA inlet and DEA
It is measured by a conductivity meter, which is one of the water quality detecting means 3 provided through a branch pipe from the inside of the high pressure heater HPTTR, the inside of the economizer ECO, the outlet of the water separator WS, and the like. In FIG. 1, voltage value data on water conductivity measured by a conductivity meter representatively showing only a conductivity meter 21 provided through a branch pipe at the outlet of the condensate booster pump CBP is AD converted. Output to the container 2. In the CRT screen of the display means 12, M
Displayed as S or KMS.

The water quality detecting means 3 for measuring the pH of the water is p
It is an H meter. By monitoring this pH, the corrosion of iron can be monitored. This pH is determined by the outlet of the condensate pump CP, the outlet of the condensate booster pump CBP, the economizer EC
It is measured by a pH meter provided from an O inlet or the like via a branch pipe. In FIG. 1, the condensate booster pump C
Representatively, only the pH meter 22 provided at the outlet of the BP via a branch pipe is shown. The value of the pH of water measured with a pH meter is
The data is output to the AD converter 2 as voltage value data. The pH value is indicated by PH on the CRT screen of the display unit 12.

Here, the abnormality detecting device of the pH meter of the present embodiment included in the water quality monitoring system will be described with reference to FIG.

The abnormality detecting device of the pH meter comprises a pH meter 22 and a conductivity meter 21 provided through a branch pipe at the outlet of the condensate booster pump CBP, and an A / D converter constituting the AD converter 2. 2a, 2b, the data recording unit 4,
PH conversion means 2 provided in the diagnostic processing means 8 for calculating the converted pH value based on the data from the conductivity meter 21 by the following formula: converted pH value = log (conductivity) +8.5656
3 and data from a pH meter 22 provided through a branch pipe at the outlet of the condensate booster pump CBP, and the pH value is compared with the converted pH value and a preset threshold value. Abnormality determination means 2 for determining the presence or absence of abnormality
5, the control operation means 13 for controlling the pH conversion means 23, the abnormality alarm generation means 7, the first storage means 9, the second storage means 10 and the like, and the display drive means 11 and the display means 12. Make up.

On the other hand, the water quality detecting means 3 for measuring the amount of dissolved oxygen in water is a dissolved oxygen meter. Monitoring the dissolved oxygen concentration can prevent corrosion in the circulation system. This is because the tendency of corrosion of iron to progress when the dissolved oxygen concentration increases is recognized. The dissolved oxygen concentration is determined by the outlet of the condensate pump CP, the inside of the low-pressure heater LPHTR, the deaerator DEA.
It is measured by a dissolved oxygen meter provided through a branch pipe from the inside and the deaerator DEA outlet, the high-pressure feed pump BFP outlet, the high-pressure heater HPHTR, the economizer ECO inlet, and the like. The dissolved oxygen concentration in the water measured by the dissolved oxygen meter is output to the AD converter 2 as voltage value data. In addition, on the CRT screen of the display means 12, the dissolved oxygen concentration is indicated by DO.

The water quality detecting means 3 for measuring the hydrazine concentration in water is a hydrazine concentration meter. Monitoring the concentration of hydrazine helps to monitor the dissolved oxygen concentration. Hydrazine is injected into the circulation to consume dissolved oxygen. This injection amount is determined so that a small amount of hydrazine remains in the economizer ECO. if,
If the amount of hydrazine injected is insufficient, the dissolved oxygen in the water cannot be completely removed, and if the dissolved oxygen is present as steam, for example, and injected into the turbine, the oxidation or corrosion of the turbine is promoted. This is because there is a disadvantage that the operable life of the power plant is shortened. Therefore, in a thermal power plant,
It is desirable to inject a predetermined amount of hydrazine into the pipe so that all of the hydrazine is consumed by dissolved oxygen before reaching the economizer ECO and a small amount of hydrazine remains in the economizer ECO. Therefore, the hydrazine concentration meter is provided via a branch pipe branched from an inlet of the deaerator DEA, an inlet of the economizer ECO, and the like. The hydrazine concentration measured by the hydrazine densitometer is output to the AD converter 2 as voltage value data. The hydrazine concentration on the CRT screen of the display means 12 is N2
Displayed in H4.

Water quality detecting means 3 for measuring the concentration of dissolved hydrogen
Is a dissolved hydrogen concentration meter. By monitoring the hydrogen concentration, the occurrence of an abnormal state in the turbine can be detected. The dissolved hydrogen concentration meter for measuring the concentration of dissolved hydrogen in water is provided in the reheater RH, the outlet of the intermediate pressure turbine IP, the economizer ECO, and the super heater SP. The concentration of dissolved hydrogen in the water measured by the dissolved hydrogen concentration meter is output to the AD converter 2 as voltage value data. The CRT on the display means 12
On the screen, the concentration of dissolved hydrogen is indicated by DH.

The water quality detecting means 3 for measuring the total iron concentration is a total iron analyzer. The measurement of the total iron concentration can monitor the generation of scale in the piping in combination with the turbidity of water described below. The total iron analyzer analyzes the iron ions in the water sampled from the condensate pump CP outlet, the inside of the low-pressure heater LPHTR, the economizer ECO, and the like in a batch process. For example, a total iron analyzer weighs sampled sample water in a sample measuring tank, guides this fixed amount of sample water to a heating tank, adds a thioglycolic acid solution, heats the solution, dissolves suspended iron, and prepares a second sample. After reducing the iron ions to ferrous ions, the solution was led to the reaction tank via a cooler. After adjusting the pH by adding an ammonium acetate buffer, the sample water colored by adding the TPTZ reagent was led to the measurement tank and the absorbance was measured. The measurement is performed, and the obtained measurement data is output to the AD converter 2 as voltage value data. The total iron concentration analyzed by the total iron analyzer is displayed in TFE on the CRT screen of the display means 12.

Incidentally, since the total iron concentration by the above-mentioned total iron analyzer is a batch process, the obtained data is discontinuous in time, and the data obtained by the above-mentioned turbidimeter is based on the principle of directly measuring the iron concentration. However, it is not possible to perform high-precision analysis because errors occur due to ionic iron present in water and variations in particle diameter.

In order to eliminate such inconveniences of the total iron analyzer and the turbidimeter, data of an arithmetic system described later is also adopted. That is, the data X from the turbidimeter is stored in the first storage means 9 continuously with time. The data output from the turbidity meter indicates the turbidity (transparency) of water in the water circulation system, and does not directly indicate the iron concentration. However, there is a correlation between the turbidity and the iron concentration obtained by manual analysis (manual analysis).

The first storage means 9 stores in advance a correlation function between the data of the turbidimeter and the data obtained by manual analysis of the iron concentration in water. This correlation function is, for example, the following linear regression line equation: Y = a + bX (where Y is data obtained by manual analysis [converted value of total iron concentration], X is data obtained by a turbidimeter, and a and b are water values in a power plant or the like). Is a coefficient that differs according to
According to this correlation function, the correlation between the output data from the turbidimeter and the data obtained by manual analysis of the iron concentration in water is at least about γ = 0.7. The data from the turbidimeter and the correlation function stored in the first storage means 9 are read out, and the control calculation means 13
This data is substituted into the correlation function to calculate the iron concentration conversion value L. The calculated iron concentration conversion value L is stored in the first storage means 9. The data Y output from the iron analyzer is also stored in the first storage means 9. This data Y indicates the iron concentration.

The control calculation means 13 synchronizes the output X of the turbidimeter continuously output with time and the output Y of the total iron analyzer. When both outputs are synchronized, the iron concentration conversion value L at the time of synchronization is read from the first storage means 9 and the iron concentration conversion value L is divided by the iron concentration conversion value Y obtained from the total iron analyzer to correct the iron concentration conversion value L. Calculate the factor Z. This correction factor Z is stored in the first storage means 9. This correction factor Z is stored in the first storage means 9 without being updated until the two outputs are next synchronized. In order to improve the accuracy of the corrected iron concentration, the correction factor Z calculated every time the two outputs are synchronized is stored in, for example, the first storage means 9 for three synchronizations, and the correction factor Z is corrected for three synchronizations. A weighted average or a weighted average of the factor Z is calculated by the control calculating means 13,
The obtained average correction factor Z may be stored in the first storage means 9. The control calculation means 13 reads the correction factor Z, multiplies the correction factor Z 'by the iron concentration conversion value L, and stores the iron concentration in the first storage means 9.

When the output data X from the turbidimeter and the output data Y from the total iron analyzer are not synchronized, the control operation means 13 immediately before the data stored in the first storage means 9 The correction factor Z 'or the average correction factor Z' obtained from the data at the time of synchronization is read out, and the correction factor Z 'is multiplied by the iron concentration conversion value L by the control calculation means 13 to obtain the obtained iron concentration. 1 storage means 9
To be stored.

The water quality detecting means 3 for measuring turbidity is a turbidity meter. By measuring the turbidity, the concentration of iron as a solid content in the circulating water can be measured, and the generation of scale in the piping can be monitored together with the total iron concentration. The turbidity meter is provided at the outlet of the condensate pump CP, the inside of the low-pressure heater LPHTR, and the branch pipe drawn from the economizer ECO or the like. As the turbidity meter, any of an absorption type and a scattered light type may be used. From this turbidity meter, the measurement data is output to the AD converter 2 as voltage value data. The turbidity analyzed by the turbidimeter is indicated by the display means 1
2 is displayed on the TV on the CRT screen.

Water quality detecting means 3 for measuring chlorine concentration in water
Is a chlorine concentration meter. By measuring the chlorine concentration, the contamination of seawater into the circulating water can be detected together with the detection of sodium ions described below. The chlorine concentration meter is provided at the end of the branch pipe drawn from the outlet of the condensate pump CP. The chlorine concentration in the water measured by the chlorine concentration meter is output to the AD converter 2 as voltage value data.

The water quality detecting means 3 for measuring the sodium concentration in the water is a sodium ion concentration meter. The measurement of the sodium ion concentration can be used together with the measurement of the chlorine concentration to detect seawater contamination in the circulating water.
The sodium ion concentration meter is provided at the end of the branch pipe drawn from the condensate demineralizer DEMI outlet. The sodium ion concentration in the water measured by the sodium ion concentration meter is output to the AD converter 2 as voltage value data.

(C) AD converter 2 The AD converter 2 converts the voltage value data which is the process signal output from the process signal generating means 1 into digital data, and outputs the voltage output from the water quality detecting means 3. It converts analog data on various water qualities as value data into digital data. The AD converter 2 outputs the converted digital data to the data recording unit 4.

(D) Data Recording Unit 4 The data recording unit 4 converts the digital data output from the AD converter 2 into engineering value data, transfers it to the first storage means 9 and stores it.

(E) Process state diagram creating means 5 Process state diagram creating means 5
The water circulation system is graphically displayed in a predetermined area of the RT screen, for example, an upper left half area of the CRT screen, and the various water quality data detected by the water quality detection means 3 and the water in the water circulation system detected by the process signal generation means 1 are displayed. The necessary data is read from the first storage means 9 so that the flow rate can be displayed at regular intervals, graphic data for displaying the water circulation system as a simple graphic, and color display of the water circulation part in the water circulation system. The color display signal, the process data indicating the water flow rate in the water circulation system, and the water quality data indicating the water quality in each part in the water circulation system are output to the second storage means 10. Further, the process state diagram creating means 5 inputs the data on the water quality in the abnormal state output from the abnormality alarm generating means 7 and displays the display data for displaying the water quality in the abnormal state in red on the CRT screen in the second color. Output to storage means 10.

(F) Trend chart creating means 6 The trend chart creating means 6 uses the CRT
The specified area stored in the first storage means 9 is displayed in a predetermined area of the screen, for example, in the upper right half area, so that a change in the specified water quality over a certain period of time can be displayed on a graph with a vertical axis and a horizontal axis. The data regarding the water quality over a certain period is read out, the water quality is converted into graphic display data to be displayed in a graph figure, and this is output to the second storage means 10.

(G) Abnormal alarm generating means 7 This abnormal alarm generating means 7 is output from the water quality detecting means 3 and the process signal generating means 1 and is stored in the first storage means 9.
Is read in real time and compared with a preset threshold value for each data. If the data read from the first storage means 9 exceeds the threshold value, data (abnormal data) exceeding the threshold value is detected. The date and time when the error occurred, the water quality item indicated by the abnormal data, the name of the department where the abnormal data occurred, and alarm information display data indicating the details of the abnormality are stored as water quality information. Further, the abnormal data is output to the process state diagram creating means 5, and
As described above, on the CRT screen, the water quality in the abnormal state in the process state diagram is highlighted in red.

(H) Diagnosis processing means 8 This diagnosis processing means 8 is adapted to perform seawater leak diagnosis, start-up process water quality diagnosis, chemical injection-related diagnosis, air leak judgment auxiliary diagnosis, and the like. Next, the operation of the thermal power plant described above will be described mainly with reference to the operation of the abnormality detection device for the pH meter and also with reference to the flowchart shown in FIG.

After the water quality monitoring system is started, it is first determined whether or not 10 minutes or more have passed since the outlet of the condensate booster pump CBP was opened (ST1). On the screen of the display means 12 under the control of 13, “condensing the booster pump outlet sample is being adjusted” is displayed (ST2).

Next, when the conductivity cross-check diagnosis for judging abnormality of the conductivity meter is not executed (ST3 negative), or the conductivity cross-check diagnosis is executed (S3).
T3 is affirmative), and when it is determined that the conductivity meter 21 is normal (ST4), under the control of the control calculation means 13, the pH conversion means 23 is connected to the outlet of the condensate booster pump CBP. The measurement data of the conductivity meter 21 provided is taken in through the A / D converter 2a and the data recording unit 5 and converted into a pH value by the above-described formula (ST).
6). If it is determined in step 4 that the conductivity meter 21 is abnormal (NO in ST4), the process is restarted (ST5).

Next, under the control of the control operation means 13, the abnormality determination means 25 controls the condensate booster pump CBP.
The measurement data provided at the outlet of the above is taken in through the A / D converter 2b and the data recording unit 5, and the pH conversion means 23
Then, the converted pH value is compared with the pH value of the pH meter 22 and a preset threshold value (ST7). If the pH value of the pH meter 22 is larger than the set upper limit value in the threshold value (YES in ST7), the pH value at the outlet of the condensate booster pump CBP is controlled under the control of the control calculation means 13.
It is determined whether or not the value alarm output is issued by the abnormality alarm generating means 7 (ST8), and if not, the pH value alarm information is sent to the display means 12 via the display driving means 11. As a result, a message of "condensate booster pump outlet pH meter indicated value high" is displayed on the screen of the display means 12 (ST9). If a pH value alarm output has been issued in step 8, it is determined whether or not this has been output as a pH meter alarm at the outlet of the pre-recovery water booster pump (ST10). If this is the case, the screen of the display means 12 displays "Condensate booster pump outlet pH
The message "Total indication value high" is continuously displayed (ST9). If the pH meter alarm was not output the previous time (NO in ST10), a message of "condensing booster pump outlet pH meter output pH meter is being diagnosed" is displayed on the screen of display means 12 (ST11).

Next, at step 7, the pH of the pH meter 22
If the value is smaller than the set upper limit in the threshold, p
The pH value of the H meter 22 is compared with the set lower limit value of the threshold value (ST12), and when the pH value is smaller than the set lower limit value (ST12).
12 Affirmative), under the control of the control calculation means 13, it is determined whether or not the pH value alarm output at the outlet of the condensate booster pump CBP has already been output by the abnormality alarm generation means 7 (ST13). If not, the pH value alarm information is sent to the display means 12 via the display drive means 13. As a result, a message of "condensate booster pump outlet pH meter reading low" is displayed on the screen of display means 12 (ST14). If a pH value alarm output has been issued in step 13, it is determined whether or not this has been output as a pre-recovery water booster pump outlet pH meter alarm (ST13).
15) If the pH meter alarm was also output last time, display means 1
On the screen of No. 2, a message of "condensate booster pump outlet pH meter indicating value low" is continuously displayed (ST14).
If the pH meter alarm was not output last time (ST1)
5 No), a message of “diagnosis of condensate booster pump outlet pH meter output pH meter is being diagnosed” is displayed on the screen of display means 12 (ST16).

Next, at step 12, the pH of the pH meter 22
When it is determined that the value is larger than the set lower limit value in the threshold value, the abnormality determination means 25 determines that the pH meter 22 is normal, and under the control of the control calculation means 13, the condensate booster pump It is determined whether or not the pH value alarm output at the exit of the CBP has already been output (ST17). If not, the information indicating that the pH meter 22 is normal is given based on the determination result of the abnormality alarm generating means 7 if not. Is sent to the display means 12. Thereby, the screen of the display unit 12 includes
A message "Condensate booster pump outlet pH meter is normal" is displayed (ST18).

The abnormality determining means 25 includes the control calculating means 1
If it is determined that the pH value alarm output at the outlet of the condensate booster pump CBP has already been issued based on the control of the step 3, the screen of the display means 12 displays "Condensate booster pump outlet pH value". The message "Alarm output pH meter normal" is displayed (ST19).

The present invention can be variously modified within the scope of the gist, in addition to the above-described embodiment. For example, in the above-described embodiment, the case where the abnormality detecting device of the pH meter is configured using the conductivity meter 21 and the pH meter 22 provided at the outlet of the condensate booster pump CBP has been described. The present invention can be implemented by using the total 22 disposed at various places in the water quality monitoring system. In the above-described embodiment, the case where the present invention is applied to a thermal power plant is described. However, the present invention can be similarly applied to a nuclear power plant and the like by changing the conversion formula.

[0067]

According to the present invention described in detail above, since the above-described configuration is employed, the presence or absence of an abnormality in a pH meter installed in a piping system in a thermal power plant is always automatically determined by using an indicated value of a conductivity meter. It is possible to provide a pH meter diagnostic device capable of making accurate and accurate determination.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a thermal power plant including an apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a water quality monitoring system in a thermal power plant including the apparatus according to the embodiment of the present invention.

FIG. 3 is a block diagram of an apparatus according to an embodiment of the present invention.

FIG. 4 is a flowchart showing a diagnostic operation of the apparatus according to the embodiment of the present invention.

[Explanation of symbols]

ST condenser C steam condenser HW condensation water tank CP condensate pump DEMI condensate demineralizer CBP condensate booster pump LPHTR low pressurizer DEA deaerator V ₁ first valve V ₂ second valve V ₃ third valve V ₄ fourth valve V ₅ fifth valve BFP pressure pump HPHTR pressure heater ECO economiser WW water wall WS water separator V ₆ sixth valve V ₇ seventh valve V ₈ 8 valve SP superheater HP high pressure turbine RH reheater IP medium-pressure turbine LP low-pressure turbine 1 process signal generating means 2 AD converter 3 water quality detecting means 4 data recording unit 5 process state diagram creating means 6 trend chart creating means 7 abnormality alarm generating means 8 diagnostic processing means 9 first storage means 10 Second storage means 11 Display drive means 12 Display means 13 Control calculation means 14 Input means 21 Conductivity meter 22 pH meter 23 pH conversion means 25 Abnormality judgment means

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Minoru Okada 3-2-2, Nakanoshima, Kita-ku, Osaka City, Osaka Prefecture Inside Kansai Electric Power Company (72) Inventor Masanori Ota 3-chome, Nakanoshima, Kita-ku, Osaka, Osaka No.22 Kansai Electric Power Co., Inc. (72) Masahiko Kurashina, Inventor 3-43-2 Ebisu, Shibuya-ku, Tokyo Nikkiso Co., Ltd. (72) Kuma, Middle East 3-43-2, Ebisu, Shibuya-ku, Tokyo No. Japan Kiso Co., Ltd. (72) Inventor Toshiaki Aoki 3-43-2 Ebisu, Shibuya-ku, Tokyo Japan Kiso Co., Ltd. (56) References JP-A-53-147593 (JP, A) JP-A Sho 60-205345 (JP, A) JP-A-50-94303 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01N 27/416 G01N 27/06 G01N 27/26 391

Claims (1)

(57) [Claims] 1. A pH meter for measuring a pH value of water circulating in a piping system of a thermal power plant, a conductivity meter for measuring conductivity of water at the same measurement position as the pH meter, and a conductivity meter. PH conversion means for obtaining a converted pH value at the measurement position based on the measured conductivity, and comparing the converted pH value obtained by the pH conversion means with the pH value measured by the pH meter, An abnormality detection device for a pH meter, comprising: abnormality determination means for determining the presence or absence of an abnormality; and display means for displaying a determination result of the abnormality determination means.