JP2016090127A - Power generation plant and operation method of power generation plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generation plant and an operation method of the power generation plant that can reduce the amount of seawater components mixed into spray water even if a seawater leak occurs in a condenser.SOLUTION: A power generation plant 1 according to the present invention comprises: a boiler 11 that generates steam S; superheaters 15, 16, and 17 that superheat the steam supplied from the boiler 11; a low-pressure turbine 14 to which the steam S superheated by the superheaters 15, 16, and 17 is supplied; a condenser 18 that cools the steam supplied from the low-pressure turbine 14 to generate condensate W; a spray water supply line Lthat supplies the condensate Was spray water Wto the steam S of the low-pressure turbine 14; a pure water production part 26 that supplies pure water Wto the spray water W; and a chemical agent supply part 28 that supplies a hydrazine based chemical agent 28a to the spray water W.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power plant and a method for operating the power plant, for example, a power plant for supplying spray water to a steam turbine and a method for operating the power plant.

  Conventionally, a method of operating a power plant that manages water quality such as condensate of a land-based thermal power plant has been proposed (see, for example, Patent Document 1). In this power plant operation method, when the quality of the sample water such as a condenser becomes an abnormal value, the emergency treatment procedure is different from the normal procedure. It becomes possible to detect more reliably than before.

JP 2013-170992 A

  By the way, in a land thermal power plant, there is a case where condensate is supplied as spray water to the steam turbine to adjust the temperature of the steam in the steam turbine. In this case, when seawater leaks in the condenser and seawater is mixed into the condensate, the spray water is mixed with seawater components such as salinity and dissolved oxygen in the seawater, and the spray water is mixed with seawater components and dissolved oxygen. Is sometimes supplied to the steam system and the turbine to cause the corrosion of the steam system and the turbine to be accelerated.

  The present invention has been made in view of such circumstances, and even when seawater leaks occur in a condenser, a power plant that can reduce the amount of seawater components and dissolved oxygen mixed in spray water, and It aims at providing the operating method of a power plant.

  The power plant according to the present invention includes a boiler that generates steam, a superheater that superheats the steam supplied from the boiler, a steam turbine that is supplied with steam that is superheated from the superheater, and a steam turbine that is supplied from the steam turbine. A condenser for cooling the steam to be condensed, a first spray water supply line for supplying the condensed water as the first spray water to the steam of the steam turbine, and supplying pure water to the first spray water And a drug supply unit that supplies a hydrazine-based drug to the first spray water.

  According to this power plant, pure water and hydrazine chemicals can be supplied to the condensate supplied to the steam turbine as the first spray water, so that the condenser leaks seawater and seawater components can be mixed into the condensate. Even so, it is possible to supply pure water into the condensate used as the first spray water, or to use pure water as the first spray water instead of the condensate. Thereby, even if it is a case where seawater leak arises with a condenser, a power generation plant can reduce the amount of seawater components, dissolved oxygen, etc. in the 1st spray water. Therefore, corrosion of the steam turbine due to intrusion of seawater components into the steam turbine due to seawater leak of the condenser can be prevented.

  In the power plant of the present invention, the superheater includes a second spray water supply line that supplies the condensed water as the second spray water, and the pure water supply unit supplies the pure water to the second spray water. The drug supply unit preferably supplies the hydrazine-based drug to the second spray water. With this configuration, the power plant can supply pure water and hydrazine chemicals to the condensate supplied to the superheater as the second spray water, so that the condenser leaks seawater and seawater components can be mixed into the condensate. Even in this case, it is possible to supply pure water to the condensate used as the second spray water, or to use pure water as the second spray water instead of the condensate. As a result, the power plant can reduce the amount of seawater components and dissolved oxygen mixed into the second spray water even when seawater leaks in the condenser. Corrosion of the superheater due to the intrusion of seawater components into the steam turbine can be prevented.

  In the power plant of the present invention, the superheater comprises: a first superheater that superheats the steam supplied from the boiler; and a second superheater that further superheats the steam superheated by the first superheater. Preferably, the second spray water is supplied to the steam heated by the first superheater. With this configuration, the power plant can reduce the amount of seawater components and dissolved oxygen mixed in the second spray water even when seawater leaks in the condenser. Corrosion of the second superheater due to intrusion of seawater components into the steam turbine due to leakage can be prevented.

  In the power plant of the present invention, the superheater includes a resuperheater that reheats the steam supplied from the steam turbine, and the second spray water is supplied from the steam turbine to the resuperheater. It is preferably supplied to the steam. With this configuration, the power plant can reduce the amount of seawater components and dissolved oxygen mixed in the second spray water even when seawater leaks in the condenser. Corrosion of the reheater due to intrusion of seawater components into the steam turbine due to leakage can be prevented.

  In the power plant of the present invention, a chloride ion measuring device for measuring the chloride ion concentration in the condensate, and the first spray water based on the chloride ion concentration measured by the chloride ion measuring device. And a control unit that controls the supply amount of pure water and the hydrazine-based drug. With this configuration, the power plant can control the supply amount of pure water and hydrazine chemicals according to the chloride ion concentration in the condensate, thus efficiently reducing the amount of seawater components and dissolved oxygen mixed in the first spray water. It becomes possible to do.

  In the power plant of the present invention, a chloride ion measuring device for measuring the chloride ion concentration in the condensate, and the second spray water based on the chloride ion concentration measured by the chloride ion measuring device. And a control unit that controls the supply amount of pure water and the hydrazine-based drug. With this configuration, the power plant can control the supply amount of pure water and hydrazine chemicals according to the chloride ion concentration in the condensate, thus effectively reducing the amount of seawater components and dissolved oxygen mixed in the second spray water It becomes possible to do.

  In the power plant of this invention, it is preferable to provide the blow water supply line which supplies the blow water from the said boiler to the said 1st spray water. With this configuration, the power plant can supply blow water to the condensate supplied to the steam turbine as the first spray water, so that the condenser leaks seawater and seawater components can be mixed into the condensate. However, it is possible to supply blow water to the condensate used as the first spray water, or to use pure water as the first spray water instead of the blow water. Thereby, even if it is a case where seawater leak arises with a condenser, the power generation plant can reduce the amount of seawater components and dissolved oxygen mixed in the first spray water.

  In the power plant of this invention, it is preferable to provide the blow water supply line which supplies the blow water from the said boiler to the said 2nd spray water. With this configuration, the power plant can supply blow water to the condensate supplied to the superheater as the second spray water, so that the condenser leaks seawater and seawater components can be mixed into the condensate. However, it is possible to supply blow water into the condensate used as the second spray water, or to use pure water as the second spray water instead of the blow water. Thereby, even if it is a case where seawater leak arises with a condenser, the power plant can reduce the amount of seawater components and dissolved oxygen mixed in the second spray water.

  The method for operating a power plant according to the present invention includes a step of measuring a chloride ion concentration of steam condensate of steam of a steam turbine in which steam superheated sequentially by a first superheater and a second superheater is supplied from a boiler; Supplying pure water and a hydrazine chemical to the condensate supplied as spray water to steam of a steam turbine based on the chloride ion concentration of the condensate.

  According to the operation method of this power plant, the supply amount of pure water and hydrazine chemicals can be controlled according to the chloride ion concentration in the condensate, so the amount of seawater components and dissolved oxygen mixed into the spray water can be reduced efficiently. It becomes possible to do. Thereby, the operation method of a power plant can reduce the amount of seawater components and dissolved oxygen mixed in the spray water even when seawater leaks in the condenser.

  The method for operating a power plant according to the present invention includes a step of measuring a chloride ion concentration of steam condensate of steam of a steam turbine in which steam superheated sequentially by a first superheater and a second superheater is supplied from a boiler; Supplying pure water and a hydrazine chemical to the condensate supplied as spray water to steam heated by a superheater based on the chloride ion concentration of the condensate.

  According to the operation method of this power plant, the supply amount of pure water and hydrazine chemicals can be controlled according to the chloride ion concentration in the condensate, so the amount of seawater components and dissolved oxygen mixed into the spray water can be reduced efficiently. It becomes possible to do. Thereby, the operation method of a power plant can reduce the amount of seawater components and dissolved oxygen mixed in the spray water even when seawater leaks in the condenser.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where seawater leak arises with a condenser, the operating method of a power plant and a power plant which can reduce the mixing amount of the seawater component and dissolved oxygen to spray water is realizable.

FIG. 1 is a schematic diagram of a power plant according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of a power plant according to the second embodiment of the present invention. FIG. 3 is a schematic diagram of a power plant according to the third embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, it is not limited to each following embodiment, It can implement by changing suitably. Also, the following embodiments can be implemented in combination as appropriate. Moreover, the same code | symbol is attached | subjected to the component which is common in each embodiment, and duplication of description is avoided.

(First embodiment)
FIG. 1 is a schematic diagram of a power plant 1 according to a first embodiment of the present invention. As shown in FIG. 1, the power plant 1 according to the present embodiment sequentially uses, for example, steam S generated from a natural circulation boiler 11 to a high-pressure turbine 12, an intermediate-pressure turbine 13, and a low-pressure turbine (steam turbine) 14. The power is supplied to drive a generator (not shown) to generate power. The boiler 11 is connected to a furnace (not shown) that generates steam by heating water supplied from a water drum (not shown), a steam drum 111 that stores the generated steam, and a steam drum 111. A water wall 112 that supplies water stored in 111 to the water drum, a salt meter 113 that detects the chloride ion concentration of boiler water in the water wall 112, and the like are provided.

The power plant 1 includes a primary superheater 15, a secondary superheater 16, a high pressure turbine 12, a resuperheater 17, and an intermediate pressure turbine that are provided from the upstream side to the downstream side in the flow direction of the steam S from the steam drum 111. 13. A low-pressure turbine 14 and a condenser 18 are provided. Further, the power plant 1, the ground which is provided from the upstream side toward the downstream side in the condensate W ₁ in the flow direction from the condenser 18 to condense the steam S from the steam drum 111 and condensed water W ₁ A steam condenser 19, a low-pressure heater 20, a deaerator 21, a high-pressure heater 22, and a economizer 23 are provided.

  The steam drum 111 supplies the steam S generated by heating from the furnace to the primary superheater 15. The primary superheater 15 superheats the steam S supplied from the steam drum 111 and supplies it to the secondary superheater 16. The secondary superheater 16 further superheats the steam S heated by the primary superheater 15 (for example, 500 ° C. or more and 650 ° C. or less) and supplies it to the high-pressure turbine 12. The high-pressure turbine 12 is driven by high-temperature and high-pressure steam S supplied from the secondary superheater 16 to drive a generator (not shown). Further, the high-pressure turbine 12 supplies the steam S whose temperature has been lowered by driving the generator to the resuperheater 17.

  The resuperheater 17 again superheats the steam S supplied from the high pressure turbine 12 and supplies the superheated steam to the intermediate pressure turbine 13. The intermediate pressure turbine 13 is driven by the steam S supplied from the resuperheater 17 to drive a generator (not shown). Further, the intermediate pressure turbine 13 supplies the low pressure turbine 14 with the steam S whose temperature has been lowered by driving the generator. The low-pressure turbine 14 is driven by the supplied steam S to drive a generator (not shown). Further, the low pressure turbine 14 supplies the condenser 18 with the steam S whose temperature has been lowered by driving the generator.

The condenser 18 includes a heat exchanger (not shown) that exchanges heat between the steam S supplied from the low-pressure turbine 14 and seawater. The condenser 18 supplies the condensate W ₁ generated from the steam S by the heat exchanger to the ground steam condenser 19 via the condensate pump P ₁ . Ground Steam condenser 19, to condense by the leakage steam S Grand condensate W ₁ and is heat exchanged. The ground steam condenser 19 supplies the condensate W ₁ condensed with the leaked steam S to the low-pressure heater 20.

A salinometer (chloride ion concentration measuring device) 24 is provided at the outlet of the condensate pump P ₁ between the condenser 18 and the ground steam condenser 19 in the condensate line L ₁ . The salt meter 24 detects the chloride ion concentration in the condensate W ₁ between the condenser 18 and the ground steam condenser 19 in the condensate line L ₁ . As a result, the power plant 1 can detect seawater leaks occurring in the condenser 18 by detecting an increase in the chloride ion concentration in the condensate W ₁ with the salt meter 24. The salt analyzer 24 transmits the measured chloride ion concentration to the control unit 25.

  The control unit 25 is, for example, a computer, a CPU, a ROM (Read Only Memory) for storing a program executed by the CPU, a RAM (Random Access Memory) functioning as a work area when executing each program, a large capacity It includes a hard disk drive (HDD) as a storage device, a communication interface for connecting to a communication network, and an access unit to which an external storage device is mounted. These units are connected via a bus. Furthermore, the control unit 25 may be connected to an input unit such as a keyboard and a mouse and a display unit including a liquid crystal display device that displays data.

The low-pressure heater 20 heats the condensate W ₁ supplied from the ground steam condenser 19 and supplies the heated condensate W ₁ to the deaerator 21. Deaerator 21 by contacting the condensate W ₁ which is heated and spray spraying to high-purity nitrogen gas, dissolved oxygen was degassed dissolved oxygen gas contained in the condensate W ₁ that is heated The concentration is reduced to a predetermined reference value or less (for example, 0.5 ppb or less). Thereby, corrosion of the steam system of the power plant 1 can be prevented. Further, the deaerator 21 sends the condensate W ₁ deaerated through the liquid feed pump P ₂ to the high-pressure heater 22.

High pressure heater 22 supplies condensate W ₁ which is degassed warmed condensate W ₁ was heated to economizer 23. The economizer 23 further heats the condensate W ₁ using the residual heat of the combustion gas of the boiler 11 and supplies it to the steam drum 111.

Between the condensate line L ₁ of the condenser 18 and the ground steam condenser 19 between the low-pressure turbine 14, spray water supplied to the low-pressure turbine 14 as a spray water W ₂ condensate W _{1 (first} spray water) supply line (first spray water supply line) L ₂ is provided. The spray water supply line L ₂ is provided with a control valve V ₁ for controlling the flow rate of the spray water W ₂ flowing through the spray water supply line L ₂ . Thus, by providing the spray water supply line L ₂ and supplying the spray water W ₂ to the low-pressure turbine 14, the temperature of the steam S of the low-pressure turbine 14 can be adjusted.

Further, between the deaerator 21 and the high-pressure heater 22 in the condensate line L ₁ and between the high-pressure turbine 12 and the resuperheater 17 in the steam system, the condensate W ₁ is sprayed with the spray water W ₃ (second spray water). ) Is provided as a spray water supply line (second spray water supply line) L ₃ for supplying the steam S supplied to the resuperheater 17. The spray water supply line L ₃ is provided with a control valve V ₂ that controls the flow rate of the spray water W ₃ flowing through the spray water supply line L ₃ . By providing the spray water supply line L ₃ in this way and supplying the spray water W ₃ to the steam S supplied to the resuperheater 17, the temperature of the steam S supplied to the resuperheater 17 can be adjusted. it can.

Further, between the high-pressure heater 22 and the economizer 23 of the condensate line L ₁ and between the primary superheater 15 and the secondary superheater 16, the condensate W ₁ is spray water W ₄ (second spray water). primary in superheater 15 heated steam S to supply the spray water supply line (second spray water supply line) L ₄ is provided as. The spray water supply line L ₄ is provided with a control valve V ₃ for controlling the flow rate of the spray water W ₄ flowing through the spray water supply line L ₄ . In this way, the temperature of the steam S supplied to the secondary superheater 16 is adjusted by providing the spray water supply line L ₄ and supplying the spray water W ₄ to the steam S heated by the primary superheater 15. Can do.

Further, power plant 1 according to the present embodiment, pure water production unit for producing pure water W ₅ supplies the spray water supply line L ₂ ~L ₄ and (pure water supply unit) 26, the pure water production unit 26 in a pure water tank 27 for storing the pure water W ₅ produced, a drug supply unit 28 for supplying a hydrazine agent 28a in pure water W ₅ supplies the spray water supply line L ₂ ~L _4, spray water supply and a pure water supply line _{L 5} which are respectively connected to the line _L 2 ~L _4. Between the pure water supply line L ₅ and the spray water supply line L _2, the control valve V ₄ for controlling the supply amount of the pure water W ₅ to the spray water supply line L ₂ it is provided. Between the pure water supply line L ₅ and the spray water supply line L _3, the control valve V ₅ for controlling the supply amount of the pure water W ₅ to the spray water supply line L ₃ is provided. Furthermore, between the pure water supply line L ₅ and the spray water supply line L _4, the control valve V ₆ for controlling the supply amount of the pure water W ₅ to the spray water supply line L ₄ it is provided.

Pure water manufacturing unit 26 is, for example, to produce distilled distilled water and demineralized water and treated water filtered by the reverse osmosis membrane filtration device seawater as pure water W _5. Further, pure water production unit 26 stores by feeding pure water W ₅ prepared in pure water tank 27. A pure water tank 27 supplies the pure water W ₅ of pure water supply line L ₅ without passing through the or liquid feed pump P ₃ via the liquid feed pump P _3. Drug supply unit 28, the addition of hydrazine agents 28a to remove dissolved oxygen in the pure water W ₅ via a liquid feed pump P _4. By thus adding a hydrazine-based agent 28a in the pure water W _5, dissolved dissolved oxygen in the pure water W _5, by atmospheric contamination from the shaft seal part of the dissolved oxygen and low pressure turbine 14 in the condenser 18 oxygen is removed, it is possible to remove dissolved oxygen in the sprayed water W ₂ to _W-4, it is possible to prevent corrosion of the low-pressure turbine 14, reheater 17 and the secondary superheater 16.

The hydrazine agents 28a, particularly limited as long as it can remove the dissolved oxygen in the pure water _{W 5} is not, for example, hydrazine _{(N 2 H 2),} hydrazine hydrate, hydrazine carbonate _{((N 2 H 2) 2} / H ₂ CO ₃ ) and various amines. Further, the addition amount of hydrazine agent 28a, the dissolved oxygen in the pure water _{W 5} from the viewpoint of efficiently removing, preferably more than 5ppm in a concentration of hydrazine agents 28a in the pure water _{W 5,} more is more 10ppm Preferably, 20 ppm or more is more preferable, 350 ppm or less is preferable, 300 ppm or less is more preferable, and 150 ppm or less is still more preferable. In view of the above, the addition amount of hydrazine agents 28a, preferably 5ppm or more 350ppm or less at a concentration of hydrazine agents 28a in the pure water _{W 5,} more preferably at least 300ppm or less 10 ppm, more preferably 20ppm or more 150ppm or less .

When the concentration of chloride ions in the condensate W ₁ at the outlet of the condensate pump P ₁ measured by the salt meter 24 exceeds a predetermined threshold, the control unit 25 closes the control valve V _1. reducing the supply amount of supplying condensate W ₁ to spray water supply line L _2. The control unit 25 supplies the pure water W ₅ where a predetermined amount of hydrazine-based drug 28a is supplied through the liquid feed pump P _3, P ₄ by opening the control valve V ₄ to the spray water supply line L _2. Thus, the power plant 1, even when seawater leakage is chloride ion concentration of condensed water W in ₁ caused rose to condenser 18, increased seawater ingredients and dissolved oxygen to the low pressure turbine 14 it is possible to prevent the supply of condensate W ₁ as spray water W _2. Control unit 25, if the chloride ion concentration in the condensate water W in _one of the outlet portion of the condensate pump P ₁ measured by Kenshiokei 24 is equal to or less than a predetermined threshold, opening the control valve V ₁ increasing the supply amount of supplying condensate W ₁ to spray water supply line L ₂ Te to. The control unit 25 stops the supply of closing the control valve V ₄ to the spray water supply line L ₂ of the pure water W ₅ where a predetermined amount of hydrazine-based drug 28a is supplied.

Control unit 25, condensate W ₁ of water wall 112 which is measured by the condensed water W chloride ion concentration and Kenshio meter 113 in ₁ has been outlet portion of the condensate pump P ₁ measured by Kenshiokei 24 When the chloride ion concentration inside exceeds a predetermined threshold value, the supply amount of the condensate W ₁ supplied to the spray water supply line L ₃ is reduced by closing the control valve V ₂ . The control unit 25 supplies the pure water W ₅ where a predetermined amount of hydrazine-based drug 28a is supplied through the liquid feed pump P _3, P ₄ by opening the control valve V ₅ to the spray water supply line L _3. Thus, the power plant 1, even when seawater leakage condenser 18 is the chloride ion concentration in the condensate water W in ₁ occurs increases, seawater ingredients and dissolved oxygen to the reheater 17 it is possible to prevent the supply of condensate W ₁ as spray water W ₃ were increased. When the chloride ion concentration in the condensate W ₁ measured by the salt meter 24 and the salt meter 113 is equal to or lower than a predetermined threshold, the control unit 25 opens the control valve V ₂ and supplies spray water. The supply amount of the condensate W ₁ supplied to the line L ₃ is increased. The control unit 25, a predetermined amount of hydrazine-based drugs 28a closes the control valve V ₅ stops the supply of the spray water supply line L ₃ of the pure water W ₅ supplied.

Control unit 25, condensate W ₁ of water wall 112 which is measured by the condensed water W chloride ion concentration and Kenshio meter 113 in ₁ has been outlet portion of the condensate pump P ₁ measured by Kenshiokei 24 When the chloride ion concentration inside exceeds a predetermined threshold value, the supply amount of the condensate W ₁ supplied to the spray water supply line L ₄ is reduced by closing the control valve V ₃ . The control unit 25 supplies the pure water W ₅ where a predetermined amount of hydrazine-based drug 28a is supplied through the control valve V ₆ is opened the liquid feed pump P _3, P ₄ to the spray water supply line L _4. Thus, the power plant 1, even when seawater leakage condenser 18 is the chloride ion concentration in the condensate water W in ₁ occurs increases, seawater ingredients and dissolved oxygen to the secondary superheater 16 The supply of the condensate W ₁ as the spray water W ₄ having increased can be prevented. When the chloride ion concentration in the condensate W ₁ measured by the salt analyzer 24 and the salt analyzer 113 becomes equal to or lower than a predetermined threshold, the control unit 25 opens the control valve V ₃ and supplies spray water. increasing the supply amount of supplying condensate _{W 1} to the line _{L 4.} The control unit 25, a predetermined amount of hydrazine-based drugs 28a closes the control valve V ₆ stops the supply of the spray water supply line L ₄ of the pure water W ₅ supplied.

Next, the overall operation of the power plant 1 according to the present embodiment will be described. The steam S generated in the steam drum 111 of the boiler 11 is successively superheated by the primary superheater 15 and the secondary superheater 16 to adjust the temperature (for example, 500 ° C. or more and 650 ° C. or less). Here, in the present embodiment, the condensate W ₁ is supplied to the steam S as the spray water W ₄ via the spray water supply line L ₄ , so that the temperature of the steam S can be easily adjusted. . When the chloride ion concentration in the condensate W ₁ detected by the salt meter 113 and the salt meter 24 exceeds a predetermined threshold, the control unit 25 controls the control valves V ₃ and V ₆ supplying pure water _{W 5} where a predetermined amount of hydrazine-based drug 28a is supplied through the liquid pump _P 3, _{P 4} as a spray water _{W 4.} Thus, the power plant 1, even when the seawater ingredients and dissolved oxygen in the condensate W ₁ by seawater leakage condenser 18 is mixed, the mixing of seawater ingredients and dissolved oxygen to steam system This makes it possible to prevent corrosion of the steam system.

The steam S heated by the secondary superheater 16 is heated again by the resuperheater 17 via the high-pressure turbine 12 (for example, 500 ° C. or more and 650 ° C. or less). Here, in the present embodiment, the condensate W ₁ is supplied to the steam S as the spray water W ₃ via the spray water supply line L ₃ , so that the temperature of the steam S supplied to the resuperheater 17 can be easily set. Can be prepared. When the chloride ion concentration in the condensate W ₁ detected by the salt meter 113 and the salt meter 24 exceeds a predetermined threshold, the control unit 25 controls the control valves V ₂ and V ₅ supplying pure water _{W 5} where a predetermined amount of hydrazine-based drug 28a is supplied through the liquid pump _P 3, _{P 4} as a spray water _{W 3.} Thus, the power plant 1, even when the seawater ingredients and dissolved oxygen in the condensate W ₁ by seawater leakage condenser 18 is mixed, the mixing of seawater ingredients and dissolved oxygen to steam system This makes it possible to prevent corrosion of the steam system.

The steam S superheated by the resuperheater 17 is supplied to the low pressure turbine 14 via the intermediate pressure turbine 13. Here, in the present embodiment, the condensate W ₁ is supplied as the spray water W _{2 to} the steam S in the low-pressure turbine 14 via the spray water supply line L _2, and therefore the temperature of the steam S in the low-pressure turbine 14. Can be easily prepared. When the chloride ion concentration in the condensate W ₁ detected by the salt analyzer 24 exceeds a predetermined threshold, the control unit 25 controls the control valves V ₁ and V ₄ and the liquid feed. supplying pure water _{W 5} where a predetermined amount of hydrazine-based drug 28a is supplied via a pump _P 3, _{P 4} as a spray water _{W 2.} Thus, the power plant 1, even when the seawater ingredients and dissolved oxygen in the condensate W ₁ by sea water leakage such as condenser 18 is mixed, seawater ingredients and dissolved oxygen into the low-pressure turbine 14 Since mixing can be prevented, corrosion of the low-pressure turbine 14 can be prevented.

The steam S discharged from the low-pressure turbine 14 becomes the condensate W ₁ through the heat exchanger in the condenser 18. The condensate W ₁ has a chloride ion concentration detected by a salt meter 24. As a result, it is possible to quickly detect the mixing of seawater components due to seawater leaks in the condenser 18. Here, in addition to the chloride ion concentration, the electrical conductivity of the condensate W ₁ may be measured to detect seawater components due to seawater leaks. Condensate W ₁ discharged from the condenser 18 is supplied to the steam drum 111 of the boiler 11 via the ground steam condenser 19, the low pressure heater 20, the deaerator 21, the high pressure heater 22, and the economizer 23.

As described above, according to the power plant 1 according to the present embodiment, the steam S heated by the primary superheater 15 as the spray water W _{2 to} W ₄ , the steam S supplied to the resuperheater 17, and the low pressure since condensate W ₁ supplied to the turbine 14 can be supplied to the pure water W ₅ containing a predetermined amount of hydrazine based agent 28a, the condenser 18 is seawater ingredients may be incorporated seawater leaked to the condensate W ₁ even if, pure water _{W 5} is fed into the condensate _{W 1} to be used as sprays water _W 2 to _W-4, or condensate _W pure water _{W 5} sprays water _W 2 to _W-4 to place the ₁ Can be used. Thus, the power plant 1, even when the seawater leakage occurs in the condenser 18, sea component and the dissolved oxygen by reducing contamination of seawater components and dissolved oxygen in the sprayed water W ₂ to _W-4 Management values (for example, 2 ppb to 20 ppb) can be maintained. Therefore, corrosion of the low-pressure turbine 14 due to intrusion of seawater components into the low-pressure turbine 14 or the like due to seawater leak of the condenser 18 can be prevented.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the following, differences from the first embodiment described above will be mainly described to avoid duplication of description.

FIG. 2 is a schematic diagram of the power plant 2 according to the second embodiment of the present invention. Power plant 2 according to the present embodiment, as shown in FIG. 2, instead of the pure water production unit 26 and a pure water tank 27 shown in FIG. 1, the blow toward the water wall 112 in the pure water supply line L ₅ water W ₆ flash tank 29 provided from the upstream side toward the downstream side in the flow direction of the blow water W ₆ of the blow water supply line L ₆ supplies, cooler 30, a filter 31 and a storage tank 32,. The blow water supply line L ₆ is provided with a control valve V ₇ and a liquid feed pump P ₅ that control the supply amount of the blow water W ₆ supplied from the blow water supply line L ₆ to the pure water supply line L ₆ . .

The flash tank 29 temporarily stores the high-temperature and high-pressure blow water W ₆ discharged from the water wall 112 and performs gas-liquid separation. Further, the flash tank 29 supplies the vapor separated from the gas and liquid to the cooler 30. The cooler 30 cools the steam supplied from the flash tank 29 and supplies it to the storage tank 32 through the filter 31 as the cooled blow water W ₆ . Filter 31 is constituted of, for example, a silver filter to remove the seawater component based on such as HCl contained in blow water W _6. The storage tank 32 temporarily stores the blow water W ₆ supplied to the pure water supply line L ₅ .

When the concentration of chloride ions in the condensate W ₁ at the outlet of the condensate pump P ₁ measured by the salt meter 24 exceeds a predetermined threshold, the control unit 25 closes the control valve V _1. reducing the supply amount of supplying condensate W ₁ to spray water supply line L _2. The control unit 25 opens the control valves V ₄ and V _7, and blow water W ₆ to which a predetermined amount of the hydrazine-based chemical 28 a is supplied by the liquid feed pumps P ₄ and P ₅ through the pure water supply line L _5. and supplies to spray water supply line L _2. Thus, power plant 2, even when seawater leakage condenser 18 is the chloride ion concentration in the condensate water W in ₁ occurs increases, increased seawater ingredients and dissolved oxygen to the low pressure turbine 14 it is possible to prevent the supply of condensate W ₁ as spray water W _2. Control unit 25, if the chloride ion concentration in the condensate water W in _one of the outlet portion of the condensate pump P ₁ measured by Kenshiokei 24 is equal to or less than a predetermined threshold, opening the control valve V ₁ increasing the supply amount of supplying condensate W ₁ to spray water supply line L ₂ Te to. Further, the control unit 25 closes the control valves V ₄ and V ₇ and stops the liquid feeding pumps P ₄ and P ₅ to stop the supply of the blow water _{6 to} the spray water supply line L ₂ .

Further, the control unit 25 controls the concentration of chloride ions in the condensate W ₁ at the outlet portion of the condensate pump P ₁ measured by the salt analyzer 24 and the condensate in the water wall 112 measured by the salt analyzer 113. If the chloride ion concentration in the W ₁ exceeds a predetermined threshold, reducing the supply amount of supplying condensate W ₁ a control valve V ₂ to the spray water supply line L ₃ is closed. Further, the control unit 25 opens the control valves V _{5 and} V ₇ and supplies blow water W ₆ supplied with a predetermined amount of the hydrazine-based chemical 28a to the spray water supply line L ₃ via the liquid feed pump P ₄ . Thus, power plant 2, even when seawater leakage condenser 18 is the chloride ion concentration in the condensate water W in ₁ occurs increases, seawater ingredients and dissolved oxygen to the reheater 17 it is possible to prevent the supply of condensate W ₁ as spray water W ₃ were increased. When the chloride ion concentration in the condensate W ₁ measured by the salt meter 24 and the salt meter 113 is equal to or lower than a predetermined threshold, the control unit 25 opens the control valve V ₂ and supplies spray water. The supply amount of the condensate W ₁ supplied to the line L ₃ is increased. Further, the control unit 25 closes the control valves V ₅ and V ₇ and stops the liquid feeding pumps P ₄ and P ₅ to supply the spray water supply line L of the blow water W ₆ to which a predetermined amount of the hydrazine-based chemical 28 a is supplied. The supply to ₃ is stopped.

Further, the control unit 25 determines the chloride ion concentration in the condensate W ₁ at the outlet portion of the condensate pump P ₁ measured by the salt meter 24 and the condensate in the water wall 112 measured by the salt meter 113. If the chloride ion concentration in the W ₁ exceeds a predetermined threshold, reducing the supply amount of supplying condensate W ₁ a control valve V ₃ to the spray water supply line L ₄ is closed. Further, the control unit 25 opens the control valves V ₆ and V ₇ and supplies blow water W ₆ supplied with a predetermined amount of the hydrazine-based chemical 28 a to the spray water supply line L ₄ via the liquid feed pump P ₄ . Accordingly, power plant 2, even when seawater leakage condenser 18 is the chloride ion concentration in the condensate water W in ₁ occurs increases, seawater ingredients and dissolved oxygen to the secondary superheater 16 The supply of the condensate W ₁ as the spray water W ₄ having increased can be prevented. When the chloride ion concentration in the condensate W ₁ measured by the salt analyzer 24 and the salt analyzer 113 becomes equal to or lower than a predetermined threshold, the control unit 25 opens the control valve V ₃ and supplies spray water. increasing the supply amount of supplying condensate _{W 1} to the line _{L 4.} The control unit 25 closes the control valves V ₆ and V ₇ and stops the liquid feed pumps P ₄ and P ₅ to supply a spray water supply line L for the blow water W ₆ to which a predetermined amount of the hydrazine-based chemical 28 a is supplied. The supply to ₄ is stopped. Since other configurations are the same as those of the power plant 1 according to the first embodiment described above, description thereof is omitted.

As described above, according to the power plant 2 according to the present embodiment, the steam S heated by the primary superheater 15 as the spray water W _{2 to} W ₄ , the steam S supplied to the resuperheater 17, and the low pressure Since the blow water W ₆ containing a predetermined amount of the hydrazine-based chemical 28 a can be supplied to the condensate W ₁ supplied to the turbine 14, the condenser 18 leaks seawater and seawater components can be mixed into the condensate W _1. Even in this case, the blow water W ₆ is supplied into the condensate W ₁ used as the spray water W _{2 to} W ₄ , or the blow water W ₆ is used instead of the condensate W ₁ as the spray water W _{2 to} W _4. Can be used. Thus, power plant 2, even if the sea water leakage occurs in the condenser 18, sea component and the dissolved oxygen by reducing contamination of seawater components and dissolved oxygen in the sprayed water W ₂ to _W-4 Management values (for example, 2 ppb to 20 ppb) can be maintained. Therefore, corrosion of the low-pressure turbine 14 due to intrusion of seawater components into the low-pressure turbine 14 or the like due to seawater leak of the condenser 18 can be prevented.

(Third embodiment)
Next, a third embodiment of the present invention will be described. In the following, differences from the first embodiment described above will be mainly described to avoid duplication of description.

FIG. 3 is a schematic diagram of a power plant 3 according to the third embodiment of the present invention. As shown in FIG. 3, the power plant 3 according to the present embodiment is obtained by adding the configuration of the power plant 2 according to the second embodiment to the configuration of the power plant 1 according to the first embodiment described above. It is. That is, the power plant 3, when the sea component and the dissolved oxygen is mixed into the seawater leakage, etc. is caused condensed water W ₁ of the condenser 18, the pure water W ₅ and the blow water W as a spray water W ₂ to _{W-4 6} is used.

When the concentration of chloride ions in the condensate W ₁ at the outlet of the condensate pump P ₁ measured by the salt meter 24 exceeds a predetermined threshold, the control unit 25 closes the control valve V _1. reducing the supply amount of supplying condensate W ₁ to spray water supply line L _2. The control unit 25, the control valve opens the _V 4, _{V 7,} pure water supply line _{L 5} feed through the pump _P 4, _{P 5} the pure water _W a predetermined amount of hydrazine-based drug 28a is supplied by the ₅ And at least one of the blow water W ₆ is supplied to the spray water supply line L ₂ . Accordingly, power plant 3, even when seawater leakage condenser 18 is the chloride ion concentration in the condensate water W in ₁ occurs increases, increased seawater ingredients and dissolved oxygen to the low pressure turbine 14 it is possible to prevent the supply of condensate W ₁ as spray water W _2. Control unit 25, if the chloride ion concentration in the condensate water W in _one of the outlet portion of the condensate pump P ₁ measured by Kenshiokei 24 is equal to or less than a predetermined threshold, opening the control valve V ₁ increasing the supply amount of supplying condensate W ₁ to spray water supply line L ₂ Te to. Further, the control unit 25 closes the control valves V ₄ and V ₇ and stops the liquid feed pumps P ₃ , P ₄ and P ₅ to stop at least one of the pure water W ₅ and the blow water W _6. The supply to ₂ is stopped.

Further, the control unit 25 controls the concentration of chloride ions in the condensate W ₁ at the outlet portion of the condensate pump P ₁ measured by the salt analyzer 24 and the condensate in the water wall 112 measured by the salt analyzer 113. If the chloride ion concentration in the W ₁ exceeds a predetermined threshold, reducing the supply amount of supplying condensate W ₁ a control valve V ₂ to the spray water supply line L ₃ is closed. The control unit 25, the control valve V _5, sprayed water at least one of V ₇ by opening the liquid feed pump pure water W P ₄ via a predetermined amount of hydrazine-based drugs 28a supplied ₅ and blow water W ₆ It is supplied to the supply line _{L 3.} Thus, the power plant 3, even when seawater leakage condenser 18 is the chloride ion concentration in the condensate water W in ₁ occurs increases, seawater ingredients and dissolved oxygen to the reheater 17 it is possible to prevent the supply of condensate W ₁ as spray water W ₃ were increased. When the chloride ion concentration in the condensate W ₁ measured by the salt meter 24 and the salt meter 113 is equal to or lower than a predetermined threshold, the control unit 25 opens the control valve V ₂ and supplies spray water. The supply amount of the condensate W ₁ supplied to the line L ₃ is increased. Further, the control unit 25 closes the control valves V ₅ and V ₇ and stops the liquid feed pumps P ₃ , P ₄ and P ₅ and supplies pure water W ₅ and blow water supplied with a predetermined amount of hydrazine-based chemical 28a. stopping the supply of at least one of the spray water supply line L ₃ of W _6.

Further, the control unit 25 determines the chloride ion concentration in the condensate W ₁ at the outlet portion of the condensate pump P ₁ measured by the salt meter 24 and the condensate in the water wall 112 measured by the salt meter 113. If the chloride ion concentration in the W ₁ exceeds a predetermined threshold, reducing the supply amount of supplying condensate W ₁ a control valve V ₃ to the spray water supply line L ₄ is closed. The control unit 25 opens the control valves V ₆ and V ₇ and sprays at least one of pure water W ₅ and blow water W ₆ supplied with a predetermined amount of the hydrazine-based chemical 28a via the liquid feed pump P ₄ as spray water. It is supplied to the supply line _{L 4.} Accordingly, power plant 3, even when seawater leakage condenser 18 is the chloride ion concentration in the condensate water W in ₁ occurs increases, seawater ingredients and dissolved oxygen to the secondary superheater 16 The supply of the condensate W ₁ as the spray water W ₄ having increased can be prevented. When the chloride ion concentration in the condensate W ₁ measured by the salt analyzer 24 and the salt analyzer 113 becomes equal to or lower than a predetermined threshold, the control unit 25 opens the control valve V ₃ and supplies spray water. increasing the supply amount of supplying condensate _{W 1} to the line _{L 4.} Further, the control unit 25 closes the control valves V ₆ and V ₇ and stops the liquid feed pumps P ₃ , P ₄ and P ₅ and supplies pure water W ₅ and blow water supplied with a predetermined amount of hydrazine chemical 28a. stopping the supply of at least one of the spray water supply line L ₄ of W _6. Since other configurations are the same as those of the power plant 1 according to the first embodiment described above, description thereof is omitted.

As described above, according to the power plant 3 according to the present embodiment, the steam S heated by the primary superheater 15 as the spray water W _{2 to} W ₄ , the steam S supplied to the resuperheater 17, and the low pressure Since at least one of pure water W ₅ and blow water W ₆ containing a predetermined amount of hydrazine chemical 28a can be supplied to the condensate W ₁ supplied to the turbine 14, the condenser 18 leaks seawater and condensate W even when the sea water components can be mixed in _1, to supply at least one of pure water W ₅ and the blow water W ₆ in condensate W ₁ to be used as sprays water W ₂ to _W-4, or condensate W Instead of ₁ , at least one of pure water W ₅ and blow water W ₆ can be used as spray water W _{2 to} W ₄ . Thus, the power plant 3, even when the seawater leakage occurs in the condenser 18, sea component and the dissolved oxygen by reducing contamination of seawater components and dissolved oxygen in the sprayed water W ₂ to _W-4 Management values (for example, 2 ppb to 20 ppb) can be maintained. Therefore, corrosion of the low-pressure turbine 14 due to intrusion of seawater components into the low-pressure turbine 14 or the like due to seawater leak of the condenser 18 can be prevented.

1, 2, 3 Power plant 11 Boiler 111 Steam drum 112 Water wall 113 Salt meter 12 High pressure turbine 13 Medium pressure turbine 14 Low pressure turbine (steam turbine)
DESCRIPTION OF SYMBOLS 15 Primary superheater 16 Secondary superheater 17 Resuperheater 18 Condenser 19 Grand steam condenser 20 Low-pressure heater 21 Deaerator 22 High-pressure heater 23 Carbon-saving device 24 Salt analyzer (chloride ion concentration measuring device)
25 Control unit 26 Pure water production unit (pure water supply unit)
27 Pure water tank 28 Chemical supply section 28a Hydrazine-based chemical 29 Flash tank 30 Cooler 31 Filter 32 Storage tank L ₁ Condensate line L ₂ Spray water supply line (first spray water supply line)
L ₃ , L ₄ spray water supply line (second spray water supply line)
L ₅ Pure water supply line L ₆ Blow water supply line S Above P ₁ condensate pump P ₂ -P ₅ liquid feed pump V ₁ -V ₇ control valve W ₁ condensate W ₂ spray water (first spray water)
W ₃ , W ₄ spray water (second spray water)
W ₅ pure water W ₆ blow water

Claims (10)

A boiler that generates steam;
A superheater that superheats steam supplied from the boiler;
A steam turbine to which superheated steam is supplied from the superheater;
A condenser for cooling the steam supplied from the steam turbine to condensate;
A first spray water supply line for supplying the condensate to the steam of the steam turbine as a first spray water;
A pure water supply unit for supplying pure water to the first spray water;
A power plant comprising: a medicine supply unit that supplies a hydrazine-based medicine to the first spray water. A second spray water supply line for supplying the condensed water as the second spray water to the superheater;
The pure water supply unit supplies the pure water to the second spray water,
The power plant according to claim 1, wherein the medicine supply unit supplies the hydrazine-based medicine to the second spray water. The superheater is a first superheater that superheats steam supplied from the boiler;
A second superheater that further superheats the steam superheated by the first superheater,
The power plant according to claim 2, wherein the second spray water is supplied to steam superheated by the first superheater.   The superheater includes a resuperheater that reheats steam supplied from the steam turbine, and the second spray water is supplied to steam supplied from the steam turbine to the resuperheater. A power plant according to claim 2 or claim 3. A chloride ion measuring device for measuring a chloride ion concentration in the condensate;
The control part which controls supply_amount | feed_rate of the said pure water and the said hydrazine type | system | group chemical | medical agent to the said 1st spray water based on the chloride ion density | concentration measured with the said chloride ion measuring apparatus was provided. Item 5. The power plant according to any one of Items 4. A chloride ion measuring device for measuring a chloride ion concentration in the condensate;
The control part which controls supply_amount | feed_rate of the said pure water and the said hydrazine type | system | group chemical | medical agent to the said 2nd spray water based on the chloride ion concentration measured with the said chloride ion measuring apparatus was provided. Item 5. The power plant according to any one of Items 4.   The power plant according to any one of claims 2 to 5, further comprising a blow water supply line that supplies blow water from the boiler to the first spray water.   The power plant according to any one of claims 2 to 5, further comprising a blow water supply line for supplying blow water from the boiler to the second spray water. Measuring the chloride ion concentration of steam condensate of steam of a steam turbine in which steam sequentially heated by the first superheater and the second superheater is supplied from a boiler;
Supplying pure water and hydrazine chemicals to the condensate supplied as spray water to steam of a steam turbine based on the measured chloride ion concentration of the condensate. how to drive. Measuring the chloride ion concentration of steam condensate of steam of a steam turbine in which steam sequentially heated by the first superheater and the second superheater is supplied from a boiler;
Supplying pure water and a hydrazine chemical to the condensate supplied as spray water to steam heated by a superheater based on the measured chloride ion concentration of the condensate, How to operate the power plant.

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