JP4993568B2 - Water treatment method and apparatus for stopping / starting a power plant - Google Patents

Description

  The present invention relates to a water treatment method and apparatus for stopping and starting a power plant.

  The power plant supplies water to the boiler, and maintains water quality by injecting chemicals such as ammonia and hydrazine into the feed water to maintain the quality of the feed water that is circulated and used in the boiler, steam-driven turbine and condenser. Means. This water treatment means performs water treatment while monitoring measurement indexes such as the electric conductivity, dissolved oxygen concentration, pH, hydrazine concentration, and iron ion concentration of the feed water. There is also known a water quality monitoring method for detecting the oxidation-reduction potential of the feed water and the corrosion potential of the boiler water pipe constituent material and monitoring the feed water quality in a unified and direct manner (see, for example, Patent Document 1). .

JP 2003-254503 A

  When shutting down a power plant by inspection or operation adjustment, the water quality is likely to deteriorate because the water supply is stagnant for a long time in the system. Is maintained. However, in the conventional water treatment method, since the amount of chemical injection at the time of stoppage cannot be monitored, the quality of the water supply during the stop period cannot be maintained if the amount of chemical injection into the water supply is small. On the other hand, if the amount of chemicals injected into the water supply is large, the concentration of the chemicals is high when the power plant is started up, resulting in a problem that the blow time of the water supply becomes long.

Also, the conventional water treatment method has a problem that it takes time for each process of the water treatment at the start-up because the water supply in the system is sampled at the start-up of the power plant and the water treatment is performed while actually measuring the water quality. It was.
Therefore, the present invention provides a water treatment method and apparatus for stopping and starting a power plant that can shorten the water treatment process at the time of starting and stopping the water treatment at the time of stopping and starting the power plant. is there.

  In order to solve the above problems, the present invention predicts a stop period when a power plant is stopped in a method for treating water supplied to a boiler of a power plant and circulated and used in a boiler, a steam-driven turbine, and a condenser. The present invention provides a water treatment method at the time of stopping / starting a power plant that injects a predetermined amount of chemicals corresponding to the predicted stop period into the feed water.

  Further, according to the present invention, a water treatment procedure at the time of starting the power plant is determined in advance corresponding to a stop period of the power plant, and the water treatment of the feed water is performed based on the water treatment procedure at the time of starting the power plant. The water treatment method at the time of stop and start of the power plant according to claim 1 is provided.

  Further, the present invention provides a water treatment apparatus for feed water that is fed to a boiler of a power plant and is circulated and used in a boiler, a steam driven turbine, and a condenser. Storage means stored corresponding to the stop period, stop period input means for inputting the predicted stop period of the power plant, and chemical injection means for injecting a chemical amount corresponding to the stop period input when the power plant is stopped into the feed water The water treatment apparatus at the time of the stop and starting of the power plant which consists of is provided.

  Further, according to the present invention, the storage means stores a water treatment procedure at the time of starting the power plant corresponding to the stop period of the power plant, and performs the water treatment of the feed water based on the water treatment procedure at the time of starting the power plant. The water treatment apparatus at the time of the stop and starting of the power plant according to claim 3 provided with water treatment means is provided.

  According to the water treatment method at the time of stopping and starting a power plant according to the present invention, in the water treatment method for feed water supplied to the boiler of the power plant and circulated and used in the boiler, the steam driven turbine and the condenser, the power plant An appropriate amount of chemicals corresponding to the stop period when the power plant is stopped by having a configuration in which a stop period is predicted at the time of stoppage and a predetermined amount of chemical is injected into the water supply corresponding to the predicted stop period. Can be injected into the feed water, and the quality of the feed water during the stop period can be reliably maintained, and the blow time at the start of the power plant can be shortened to shorten the start-up time.

  Further, according to the present invention, a water treatment procedure at the time of starting the power plant is determined in advance corresponding to a stop period of the power plant, and the water treatment of the feed water is performed based on the water treatment procedure when the power plant is started. By having the configuration according to claim 1, the power plant can maintain the quality of the feed water by the water treatment procedure corresponding to the stop period without sampling the water in the feed water system and measuring the water quality when starting the power plant. Can be activated and the activation time can be further shortened.

  Further, according to the water treatment device at the time of stopping and starting the power plant according to the present invention, in the water treatment device for feed water supplied to the boiler of the power plant and circulated and used in the boiler, the steam driven turbine and the condenser, Storage means for storing the amount of chemical injected into the water supply when the power plant is stopped corresponding to the power plant stop period, stop period input means for inputting the predicted power plant stop period, and the stop input when the power plant is stopped By comprising a chemical injection means for injecting a chemical amount corresponding to the period into the feed water, an appropriate chemical amount corresponding to the stop period can be injected into the feed water when the power plant is stopped. The water quality of the feed water can be reliably maintained, and the blow time at the start-up of the power plant can be shortened to shorten the start-up time.

  Further, according to the present invention, the storage means stores a water treatment procedure at the time of starting the power plant corresponding to the stop period of the power plant, and performs the water treatment of the feed water based on the water treatment procedure at the time of starting the power plant. By having the structure of Claim 3 provided with the water treatment means, the water quality of the feed water by the water treatment procedure corresponding to the stop period without sampling the water in the feed water system at the time of starting the power plant and measuring the water quality It is possible to start the power plant while maintaining the above, and to further shorten the startup time.

Embodiments of the present invention will be described based on examples shown in the drawings.
The water treatment device at the time of stopping / starting a power plant according to the present invention is configured so that water supplied to a boiler of a power plant can be treated with water used for circulation in a boiler, a steam driven turbine, and a condenser. Yes, storage means 1 that stores the amount of chemical injected into the water supply when the power plant is stopped corresponding to the power plant stop period, stop period input means 2 that inputs a predicted power plant stop period, and when the power plant stops It is comprised from the chemical | medical agent injection | pouring means 3 which inject | pours the chemical | medical agent quantity corresponding to the input stop period into the said water supply.

FIG. 2 shows a water treatment system diagram of the water supply. The feed water is circulated through a condensate system 10 that cools the steam with cooling water and returns it to the water, a feed water system 11 that boosts the condensate and feeds it to the boiler, and a steam system 12 that feeds steam generated in the boiler to the turbine. Have been used.
In FIG. 2, reference numeral 13 denotes a sampling point, which can collect water supply and measure water quality such as pH value, electrical conductivity, hydrazine concentration, and iron ion concentration. Reference numeral 14 denotes a chemical injection point, which is configured so as to maintain the quality of the boiler water by injecting chemicals such as hydrazine into the boiler water.

  In the embodiment shown in FIG. 1, the storage means 1 comprises a central control device 5 or a storage device such as a hard disk of a terminal connected to the central control device 5. The storage means 1 stores the chemical amount storage means for storing the chemical amount injected into the feed water when the power plant is stopped corresponding to the power plant stop period, and the water treatment procedure at the time of starting the power plant corresponding to the power plant stop period. Water treatment procedure storage means for storing is provided.

  As shown in FIG. 2, the chemical amount storage means sets the power plant stop period to DSS (daily start / stop), hot banking WSS (weekend start / stop), forced cooling WSS, LSS (long-term start / stop). Classified. The chemical amount storage means stores a chemical amount such as hydrazine or ammonia to be injected into the water supply in accordance with the classification of the stop period. In WSS, while the stop period is short (hot banking state), the pressure in the boiler is higher than the atmospheric pressure, and the boiler is sealed against the outside air, but when the stop period is long, the pressure in the boiler decreases. In order to facilitate the entry of oxygen, the chemical amount is managed by dividing the classification into a hot banking state and a forced cooling state.

  As shown in FIGS. 4 to 6, the water treatment procedure storage means stores a water treatment procedure at the time of starting the power plant corresponding to the stop period of the power plant. 4 shows the water treatment procedure at the time of startup from DSS, FIG. 5 shows the water treatment procedure at the time of startup from WSS (hot banking), and FIG. 6 shows the water treatment procedure at the time of startup from WSS (forced cooling). Yes. The water treatment procedure storage means stores the injection amount of chemicals such as hydrazine and ammonia into the water supply when the power plant is activated, and stores the water supply blow time corresponding to the stop period.

  In the embodiment shown in FIG. 1, the stop period input means 2 is composed of a terminal such as a personal computer connected to the central controller 5 and is configured to be able to input the predicted stop period of the power plant. The predicted stop period input from the stop period input means 2 is sent to the central controller 5.

  The chemical injection means 3 can call the chemical amount corresponding to the predicted stop period input from the stop period input means 2 from the storage means 1 and inject chemicals such as hydrazine and ammonia into the water supply based on the chemical amount. It is constituted as follows. In the embodiment, the amount of the chemical injected into the water supply can be adjusted by the concentration of the chemical, the stroke of the injection pump, the injection time, and the like.

  The water treatment means 4 is configured to call a water treatment procedure corresponding to the stop period from the storage means 1 when the power plant is started, and to perform water treatment of the feed water based on the water treatment procedure. Since the water treatment means 4 determines the water treatment procedure corresponding to the stop period, as shown in FIGS. 4 to 6, it is not necessary to measure the water quality in each chemical injection step and the blow step, and the water supply before ignition The water treatment can be performed only by confirming the electrical conductivity. Moreover, the water treatment means 4 can switch to chemical | medical agent injection | pouring automatically after confirmation of electrical conductivity, and can transfer to the water treatment process at the time of normal operation.

  The storage unit 1 includes a changing unit that can change the chemical amount and the water treatment procedure stored in the storage unit 1 so as to cope with a change in the chemical injection amount due to the equipment update of the power plant. Preferably it is.

The block diagram which shows one Example of the water treatment apparatus at the time of the stop of the power plant which concerns on this invention, and starting. The water treatment system figure of the water supply of the one Example. The figure explaining the relationship between the stop period of the one Example, and water treatment. The chart figure which shows an example of the water treatment at the time of the one Example. The chart figure which shows another example of the water treatment at the time of the one Example. The chart figure which shows another example of the water treatment at the time of the one Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Memory | storage means 2 Stop period input means 3 Chemical injection means 4 Water treatment means 5 Central controller 10 Condensate system 11 Water supply system 12 Steam system 13 Sampling point 14 Chemical injection point

Claims (2)

In a water treatment method for feed water that is supplied to a boiler of a power plant and circulated and used in a boiler, a steam-driven turbine, and a condenser,
A chemical amount storage means for storing a chemical amount to be injected into the water supply when the power plant is stopped corresponding to a power plant stop period, and a water process for storing a water treatment procedure at the time of power plant startup corresponding to the power plant stop period A procedure storage means,
A prediction process for predicting the outage period when the power plant is shut down;
A chemical injection step of injecting the chemical amount stored in the chemical amount storage means into the water supply corresponding to the predicted stop period ;
A water treatment step of performing water treatment of the feed water based on a water treatment procedure stored in the water treatment procedure storage means at the time of power plant startup,
The said water treatment process is the water treatment method at the time of the stop and starting of a power plant which made it transfer to the water treatment at the time of normal operation, after confirming the electrical conductivity of the said water supply . In a water treatment system for water supplied to a boiler of a power plant and circulated and used in a boiler, a steam driven turbine and a condenser,
A chemical amount storage unit storing a chemical amount to be injected into the water supply when the power plant is stopped corresponding to a power plant stop period, and water storing a water treatment procedure at the time of power plant start corresponding to the power plant stop period Storage means including a processing procedure storage unit ;
A stop period input means for inputting a predicted stop period of the power plant;
A chemical injection means for injecting into the feed water a chemical amount corresponding to the stop period input when the power plant is stopped ;
Water treatment means for performing water treatment of the feed water based on a water treatment procedure stored in the storage means at the time of power plant startup,
The said water treatment means is a water treatment apparatus at the time of the stop and start-up of a power plant which made it transfer to the water treatment at the time of normal operation, after confirming the electrical conductivity of the said water supply .

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