JP3109754B2 - Hydrazine injection abnormality monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrazine injection abnormality monitoring apparatus for a thermal power plant.

[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.

[0008] Such water quality management items are obtained by displaying data obtained by detectors and the like arranged at various points in the water circulation system on an instrument provided on a wall surface of a centralized monitoring device or the like and recording the data on a recording device. I was The observer discovered abnormal data from various types of detected data displayed on the instrument, comprehensively judged the various types of abnormal data, detected the cause of the abnormality, the location where the abnormality occurred, and took action. However, in such a monitoring method that relies on the experience of a supervisor, even if an abnormal state can be detected, it takes time to detect the location of the abnormality and to investigate the cause of the abnormality or to study the countermeasures. However, there is a problem that one has to rely on a skilled guard.

Incidentally, such a thermal power plant is provided with a hydrazine injection monitoring system to assist in monitoring the amount of dissolved oxygen in the circulating water. An outline of a conventional hydrazine injection monitoring system will be described below. A conventional hydrazine injection monitoring system includes an injection pump as a hydrazine injection device for injecting hydrazine into a piping system, a hydrazine tank for storing hydrazine to be injected, and a hydrazine meter for measuring the concentration of hydrazine injected by the injection pump. And an injection control means for controlling the injection amount of hydrazine by the injection pump based on the measurement value of the hydrazine meter.

[0010]

In such a conventional system, an abnormality may occur in the infusion pump, or the concentration of the hydrazine tank may become higher or lower than a steady value. If there is an abnormality in the infusion pump, the hydrazine meter continues to measure a certain measured value even if the stroke length of the plunger is 0% or 100%, and the infusion control means continues the control operation.
However, the hydrazine concentration of water in the main pipe of the piping system does not become an appropriate value.

On the other hand, for example, if the concentration of hydrazine becomes much higher than the steady value for some reason, the injection control means makes the stroke length of the plunger smaller, and as a result, the measured value of the hydrazine meter becomes smaller. turn into. Since the injection control means controls the plunger to increase the stroke length, the measured value of the hydrazine meter increases again. That is, the hydrazine concentration in the water in the main pipe changes with time. Accordingly, an object of the present invention is to provide a hydrazine injection abnormality monitoring device capable of constantly monitoring the concentration of hydrazine injected into a piping system in a thermal power plant so as to be an appropriate value.

[0012]

[MEANS FOR SOLVING THE PROBLEMS]
The present invention is applied to a piping system in a thermal power plant.
Concentration of hydrazine injected by hydrazine injection means
A hydrazine injection abnormality monitoring device for monitoring
Hydrazine meter connected to piping systemMeasured data by
Determined by collecting past data on drazine concentration
Concentration monitoring unit that monitors whether the value is within the set value range
Hydrazine injection means by the hydrazine injection means
Injection state detecting means for detecting the stateData measured by
Settings determined by aggregating past data on the input status
Pump monitoring unit that monitors whether the value is within the rangeWhen,Hi
Based on the measured data of the drazine meter,
A control monitoring unit that monitors whether the control of the stage is abnormal;
If an abnormality is found in the degree monitoring unit or pump monitoring unit,
The monitoring unit determines whether the hydrazine injection state is abnormal.
Hydrazine injection control is defective
Hydrazine injection means.
After switching and switching, the concentration monitoring unit and pump monitoring unit
If it is determined to be normal, the hydrazine injection means will determine that it is abnormal,
After switching, the concentration monitor and pump monitor are judged to be abnormal.
The hydrazine injection means is normal and the hydrazine tank
Determining means for determining switching,Judgment by this judgment means
Display means for visually displaying the result.Features
Hydrazine injection monitoring in thermal power plant
Vision deviceIt is.

[0013]

The operation of the above hydrazine injection abnormality monitoring device will be described below. The hydrazine meter connected to the piping system measures the concentration of hydrazine injected by hydrazine injection means into the piping system in the thermal power plant. The injection state detecting means detects an injection state of hydrazine by the hydrazine injection means, and sends out a detection result. The concentration monitoring unit includes a hydrazine connected to the piping system.
Data from hydrazine concentration
Data is within the set value range determined by integrating the data
Monitor whether it is. The pump monitoring unit includes the hydrazine
Injection state to detect the injection state of hydrazine by injection means
The measurement data by the condition detection means
Data is within the set value range determined by integrating the data
Monitor whether it is. The control and monitoring unit measures the hydrazine
Whether the control of the hydrazine injection means is abnormal based on the data.
Watch out.

[0014] The determining means may include the concentration monitor or the pump monitor.
If an abnormality is found in the viewing unit, the control monitoring unit
Judge whether the drazine injection state is abnormal or not.
Hydrazine injection control is judged to be defective and normal
Switch the hydrazine injection means, and after switching
If the concentration monitor and pump monitor determine that
Determine that the azine injection means is abnormal and switch
If the visual inspection unit and the pump monitoring unit determine that there is an error,
The input means is normal and the hydrazine tank switching is determined. This determination result is visually displayed by the display unit. With the above operation, the cause of the presence or absence of the abnormality in the concentration of hydrazine can be constantly monitored.

[0015]

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. The outline of this thermal power plant is shown in FIG. (A) Water Circulation System in Thermal Power Plant-Structure of Water Circulation System-As shown in Figs. 1 and 2, the condensing system condenses the work-completed steam in a cooling pipe ST that conducts seawater to form a liquid. The 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, and a condensate booster pump CBP for feeding water (demineralized water) from which ionic substances have been removed
And a low pressure heater LPHTR for heating the supplied water,
It has 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.

[0016] 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 provided in a pipe connecting the condensate demineralizer DEMI and the condensate booster pump CBP. An infusion pump P as means is connected, and hydrazine is supplied to the infusion pump P by a hydrazine tank HDT.

The injection pump P has a stroke sensor SS and a rotation sensor KS as injection state detecting means. The stroke sensor SS measures the stroke of the plunger in the infusion pump P and sends out measurement data. The rotation sensor KS is
The number of rotations of the infusion pump P is measured, and measurement data is transmitted.

A hydrazine meter HD for measuring hydrazine concentration is connected to a branch pipe branched from an inlet of an economizer ECO described later. The hydrazine meter HD sends measured data, and controls the plunger stroke length of the injection pump P by the injection control means HDC.

The water supply system includes a high-pressure water supply pump BFP for producing high-pressure water by sending water discharged from the deaerator DEA to a pipe narrowed to a small diameter, and a high-pressure water pump BFP sent from the high-pressure water supply pump BFP. -Pressure heater HPHTR for pre-heating water, and economizer ECO for pre-heating high-pressure water pre-heated by the high-pressure heater HPHTR to a higher temperature
And a water wall WW for converting high-pressure high-temperature water preheated to a high temperature in the economizer ECO to high-pressure steam, and high-pressure high-temperature water converted to steam and high-pressure high-temperature water not converted to steam by the water wall WW. And a water separator WS for separation.

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. 3 shows a configuration of a water quality monitoring system. As shown in FIG. 3, the water quality monitoring system includes a process signal generating means 1 in the water circulation system, an AD converter 2 for converting a voltage signal output from the process signal generating means 1 into a digital signal, A water quality detection means 3 installed in the system and detecting the quality of water and outputting the same as voltage value data; an AD converter 2 for converting voltage value data output from the water quality detection means 3 into a digital value; A
A data recording unit 4 for converting data from the water quality detecting means 3 and the process signal generating means 1 via the D converter 2 into engineering value data; a process signal generating means 1, the water quality detecting means 3 and an abnormal alarm generating means to be described later 7, the water circulation system is graphically displayed based on the data output from the control unit 7, the water quality data and the 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. The 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 displayed in a time-sequential graph with respect to the designated water quality item in a time-series manner. Data output from the trend diagram creating means 6 to be processed, the process signal generating means 1 and the water quality detecting means 3 are input. An abnormal alarm generating means 7 for processing data so as to display the item of the abnormal water quality, the location of the abnormal water quality, the date and time of occurrence, the content of the abnormality, etc., the process signal generating means 1, and the water quality detection. The data output from the means 3 is input, and the past water quality data is input from the first storage means 9 to be described later to diagnose the diagnostic information for supporting the operation of the thermal power plant and the cause of the abnormal water quality. Diagnostic processing means 8 for processing data so as to display the contents thereof; first storage means 9 for storing real-time data and past data output from process signal generating means 1 and water quality detecting means 3; When,
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, a display driving means 11 for reading out image data from the second storage means and outputting it to the display means 12, and inputting image data outputted from the display driving means 11 and outputting from the process state diagram creating means 5 Based on the data, the water supply system in the thermal power plant,
The water quality in each part of the circulation system is based on the process state diagram for displaying the water quality information on the current water quality in each part of the water circulation system circulating through the steam system and the condensing system, and the data output from the trend diagram creating means 6. Diagram displaying water quality history information on the history of the alarm, abnormal alarm generating means 7
Based on the data output from the system, the driving support information on the water quality and the cause of the abnormal state based on the data output from the diagnosis processing means 8 are diagnosed, and the water quality information on the water quality management is displayed in four areas on the screen. Display means 12 for independently displaying the information, and control calculation means 1 for controlling and calculating the respective means.
3 and input means 14 for instructing the control operation means 13 to operate or inputting predetermined data.

Here, a hydrazine injection abnormality monitoring apparatus according to an embodiment of the present invention will be described. As shown in FIG. 4, the hydrazine injection abnormality monitoring device includes the hydrazine meter HD, the stroke sensor SS, the rotation sensor KS, and three AD converters 2a and 2b constituting the AD converter 2. , 2c, the control calculation means 13, the abnormality alarm generation means 7, the diagnosis processing means 8, the first storage means 9, the second storage means 10, the display drive means 11 and the display means 12, I have it.

The diagnostic processing means 8 includes a control section 21 for controlling the whole apparatus and a concentration monitoring section 22 for monitoring measurement data of the hydrazine concentration measured by the hydrazine meter HD.
A pump monitoring unit 23 for monitoring the state of injection by the injection pump P, that is, a stroke length detected by the stroke sensor SS and measurement data of a rotation speed detected by a rotation speed sensor KS, and a hydrazine meter HD. Based on the measured data, a control monitoring unit 24 that monitors the control state of the injection control unit HDC that controls the stroke length of the injection pump P, and an abnormality detected by the concentration monitoring unit 22 and the pump monitoring unit 23 And a determination unit 25 for transmitting data to the control monitoring unit 24 or determining the cause of the abnormality.

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-mentioned 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 items detected by the water quality detection means 3 are 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 electric conductivity of water includes:
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.

The voltage value data on the water conductivity measured by the conductivity meter is output to the AD converter 2. The CRT screen on the display means 12 is displayed in MS 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. The pH value of the water measured by the pH meter 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.

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,
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 HD. 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 the injection amount of hydrazine is insufficient, the dissolved oxygen in the water cannot be completely removed.If the water with dissolved oxygen is turned into steam, for example, and injected into the turbine, the oxidation or corrosion of the turbine may occur. This is because of the disadvantage that the operable life of the power plant is shortened due to the promotion. Therefore, in a thermal power plant, a predetermined amount of hydrazine is injected into the pipe so that hydrazine is consumed by dissolved oxygen before reaching the economizer ECO, and hydrazine slightly remains in the economizer ECO. Is desirable.

As described above, the condensate booster pump C
Hydrazine is injected by the injection pump P through the branch pipe at the inlet of the BP, and the concentration of hydrazine is measured by a hydrazine meter HD connected to the branch pipe at the inlet of the economizer ECO.
The measured concentration is sent to the injection control means HDC, and the injection control means HDC compares the sent concentration with a preset concentration, commands the stroke length, and controls the hydrazine concentration. The hydrazine concentration is displayed in N2H4 on the CRT screen of the display unit 12.

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 total iron analyzer is a batch process, the data obtained is discontinuous in time, and the data by the turbidity meter 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 inconvenience of the total iron analyzer and the turbidity meter, 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 operation 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 is used. 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 the intrusion of seawater into 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 the engineering value data to the first storage unit 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 above-mentioned thermal power plant will be described mainly on the operation of the hydrazine meter injection abnormality monitoring device.

After the water quality diagnosis system is started, the measurement data of the hydrazine meter HD is digitized by the AD converter 2c, passes through the data recording unit 4, and is controlled by the control arithmetic unit 13 in the concentration monitoring unit 22 in the diagnosis processing unit 8. Sent to Concentration monitoring unit 22 at which the measurement data of the hydrazine meter HD is stored in the first storage unit 9, hydrazine
The control unit 21 monitors whether or not the data is within a set value determined by collecting past data relating to the concentration of the toner. The state of hydrazine injection by the hydrazine pump P, that is, the stroke length and rotation speed sensor KS of the injection pump P detected by the stroke sensor SS.
The measured data of the rotation speed of the infusion pump P detected by the A / D converter are digitized by the A / D converters 2a and 2b, and then sent to the pump monitoring unit 23 of the diagnosis processing unit 8 by the control calculation unit 13 via the data recording unit 4. Can be Pump monitoring unit 23, the stroke length and rotation speed data of the infusion pump P is where it was stored in the first storage unit 9, the pump
Past data on P stroke length and rotation speed data
The data is monitored to see if it is within the range of the set value determined collectively and sent to the control unit 21.

The control section 21 sends data to the determination section 25 when either the concentration monitoring section 22 or the pump monitoring section 23 has an abnormality. The determination unit 25 sends the measurement data of the hydrazine meter HD and the data of the stroke length of the infusion pump P to the control monitoring unit 24, and the control monitoring unit 24 monitors the tendency of the behavior of the stroke length with respect to the measurement data of hydrazine,
Whether the control is abnormal or not is sent to the determination unit 25 again. Judgment unit 25
When the determination of the control monitoring unit 24 is abnormal, the control unit 2
1, the control unit 21 displays a message of “hydrazine injection control failure” on the screen of the display unit 12 via the control calculation unit 13 and the display drive unit 11.

When the judgment by the control monitoring unit 24 is normal, the judgment unit 25 sends information to the control unit 21 and
Displays a message "switch hydrazine pump" on the screen of the display means 12 via the control operation means 13 and the display drive means 11. After switching the hydrazine pump HDP, the above-described concentration monitoring unit 22 and pump monitoring unit 23
If the abnormality determined in the step is improved, a "pump abnormality" message is output by the same operation as described above. Concentration monitoring unit 2
2 or if the abnormality determined by the pump monitoring unit 23 is not improved, a message of “pump normal, tank switching” is displayed by the same operation as described above, and thereafter, the determination unit 25 determines the cause of the abnormality by the same operation. .

By such an operation, it is possible to always automatically monitor whether or not the hydrazine injection state is abnormal. The present invention can be variously modified within the scope of the gist, in addition to the above-described embodiment.

[0064]

According to the present invention described in detail above, the hydrazine injection system capable of constantly and automatically monitoring the presence or absence of an abnormality in the injection state of hydrazine in the piping system of a thermal power plant because of the above-described configuration. An abnormality monitoring device can be provided.

[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 partial schematic configuration diagram of a thermal power plant including the apparatus according to the embodiment of the present invention.

FIG. 3 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. 4 is a block diagram of an apparatus according to an 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 Control unit 22 Concentration monitoring unit 23 Pump monitoring unit 24 Control monitoring unit 25 Judgment unit

Continued on the front page (72) Inventor Minoru Okada 3-2-2, Nakanoshima, Kita-ku, Osaka-shi, Osaka Inside Kansai Electric Power Company (72) Inventor Masanori Ota 3-2-2, Nakanoshima, Kita-ku, Osaka-shi, Osaka Inside Kansai Electric Power Co., Inc. (72) Inventor Masahiko Kurashina 3-43-2 Ebisu, Shibuya-ku, Tokyo Japan Machinery Co., Ltd. (72) Inventor Hisawazu Middle East 3-43-2 Ebisu, Shibuya-ku, Tokyo Japan Machine (72) Inventor Toshiaki Aoki 3-43-2 Ebisu, Shibuya-ku, Tokyo Nikkiso Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) C23F 11/14 C02F 1 / 00

Claims (1)

(57) [Claims] 1. A hydrazine injection abnormality monitoring device for monitoring the concentration of hydrazine injected into a piping system of a thermal power plant by hydrazine injection means, the measurement data being obtained by a hydrazine meter connected to the piping system.
Collects past data on hydrazine concentration
Concentration monitor to check whether the measured value is within the set value range.
A visual part, and measurement data obtained by an injection state detection means for detecting an injection state of hydrazine by the hydrazine injection means.
Is determined by aggregating past data on injection conditions
A pump monitoring unit <br/> for monitoring whether or not within the scope of the set value, based on the measurement data of the hydrazine meter, the hydrazine
A control monitoring unit that monitors whether control of the injection means is abnormal,
Abnormality is found in the concentration monitor or pump monitor
The hydrazine injection state is abnormal in the control monitoring unit
Hydrazine injection system
Hydrazine injection when control is judged to be defective and normal
Switching means, after switching, concentration monitoring unit and pump
If the monitoring unit judges that the hydrazine injection means is abnormal,
After the judgment and switching, the concentration monitoring unit and the pump monitoring unit
If it is determined to be abnormal, the hydrazine injection means is normal and the hydrazine
A hydrazine injection abnormality monitoring device for a thermal power plant , comprising: a determination unit for determining whether to switch the fuel tank ; and a display unit for visually displaying the determination result of the determination unit.