JP4814077B2 - Turbine equipment, exhaust heat recovery boiler device, and operation method of turbine equipment - Google Patents

Description

  The present invention relates to a turbine facility capable of long-term continuous operation, an exhaust heat recovery boiler device, and a method for operating the turbine facility.

  From the viewpoint of effective use of energy resources and economic efficiency, various efficiency improvements have been made in power generation facilities (power generation plants). For example, a turbine power plant (combined power plant) combining a gas turbine and a steam turbine is one of them. In a combined power plant, high-temperature exhaust gas from a gas turbine is sent to an exhaust heat recovery boiler device, steam is generated in the exhaust heat recovery boiler device via a heating unit, and the generated steam is sent to a steam turbine to generate steam. I'm starting to work on a turbine. The heating unit has a economizer, superheater, boiler (drum and evaporator), etc. In order to improve the heat recovery rate of the boiler, multiple stages (for example, high pressure, medium pressure, low pressure) Is provided. Each of the high pressure, medium pressure, and low pressure heating units is provided with a superheater, a drum, and the like.

In the exhaust heat recovery boiler apparatus, multiple heating units are provided for each pressure, a number of pipes through which water, steam, etc. are sent between the units, and a pipe through which steam is sent between the steam turbines are provided. ing. These pipes are subjected to phosphate treatment or alkali treatment (water treatment) to prevent erosion / corrosion. Specifically, sodium phosphate or caustic soda is injected into the drum of the heating unit to perform phosphate treatment or alkali treatment to prevent erosion / corrosion in the piping.
In the water treatment in the conventional exhaust heat recovery boiler device, erosion and corrosion in the piping is prevented by phosphate treatment and alkali treatment, but in the exhaust heat recovery boiler device in which the heating unit is provided in multiple according to pressure, There has been a problem that the injected sodium phosphate and alkali are concentrated particularly in the high-pressure boiler section to cause alkali corrosion. In recent years, the regulation of phosphorus emitted from environmental problems has become a problem.

In view of the above problems, the present inventors have proposed that high pH operation be attempted (Patent Document 1).
An overall system diagram of the turbine equipment provided with the exhaust heat recovery boiler apparatus according to this proposal is shown in FIG. As shown in FIG. 9, the exhaust gas from the gas turbine 1 is sent to the exhaust heat recovery boiler 2, and the exhaust heat recovery boiler 2 includes a high pressure heating unit 3, an intermediate pressure heating unit 4, and a low pressure heating unit. 5 is provided. In the exhaust heat recovery boiler 2, steam is generated via the high-pressure heating unit 3, the intermediate-pressure heating unit 4, and the low-pressure heating unit 5, and the generated steam is sent to the steam turbine 6 to work on the steam turbine 6. ing. Exhaust gas from the steam turbine 6 is condensed and condensed by a condenser 8 and introduced into the exhaust heat recovery boiler 2 by a condensate pump 9. The exhaust heat recovery boiler device is configured by a water supply line 7 (a water supply system) from the exhaust heat recovery boiler 2 and the condensate pump 9.

  The high pressure heating unit 3 includes a high pressure superheater 11, a high pressure drum 12, a high pressure evaporator 13, and a high pressure economizer 14. Water in the high-pressure drum 12 is superheated and circulated in a high-pressure evaporator 13 disposed in the exhaust heat recovery boiler 2 to generate high-pressure steam in the high-pressure drum 12. The high-pressure steam generated in the high-pressure drum 12 is heated by the high-pressure superheater 11 disposed in the exhaust heat recovery boiler 2 and introduced into the steam turbine 6.

  The intermediate pressure heating unit 4 includes an intermediate pressure superheater 21, an intermediate pressure drum 22, an intermediate pressure evaporator 23, and an intermediate pressure economizer 24. Water in the intermediate pressure drum 22 is superheated and circulated in an intermediate pressure evaporator 23 disposed in the exhaust heat recovery boiler 2 to generate intermediate pressure steam in the intermediate pressure drum 22. The medium pressure steam generated in the medium pressure drum 22 is introduced into the reheater 25 through the medium pressure superheater 21, reheated by the reheater 25, and introduced into the steam turbine 6. The steam from the intermediate pressure superheater 21 is introduced to the gas turbine 1 side for cooling the high temperature portion (combustor, blades, etc.) of the gas turbine 1.

  The low pressure heating unit 5 includes a low pressure superheater 31, a low pressure drum 32, a low pressure evaporator 33, and a low pressure economizer 34. Water in the low-pressure drum 32 is superheated and circulated by a low-pressure evaporator 33 disposed in the exhaust heat recovery boiler 2, and low-pressure steam is generated in the low-pressure drum 32. The low pressure steam generated in the low pressure drum 32 is introduced into the steam turbine 6 through the low pressure superheater 31.

  Condensate 50 from the condenser 8 is supplied to the low pressure drum 32 via the deaerator 10 and the low pressure economizer 34. A water supply line 41 connected to the high pressure drum 12 and the intermediate pressure drum 22 is provided in the flow path on the outlet side of the low pressure economizer 34, and water is supplied from the water supply line 41 to the high pressure drum 12 via the high pressure water supply pump 42. The intermediate pressure drum 22 is supplied with water through the intermediate pressure water supply pump 43. That is, water is supplied to the low-pressure drum 32, the intermediate-pressure drum 22 and the high-pressure drum 12 in parallel. The low-pressure drum 32 is a low-pressure unit drum, and the intermediate-pressure drum 22 and the high-pressure drum 12 are the high-pressure side. It is considered as a unit drum. Reference numeral 44 denotes a circulation pump that circulates water supplied from the low-pressure economizer 34.

  A part of the condensate 50 is returned to the condenser 8 on the inlet side of the deaerator 10, and a part of water is returned to the deaerator 10 side by branching from the water supply line 41. . The arrangement of each device in the exhaust heat recovery boiler 2 is an example, and the number and arrangement of the economizers and superheaters are appropriately changed depending on the performance of the gas turbine 1 and the like.

  A water supply line 7 serving as a water supply system is provided with a chemical injection means 45 for injecting a chemical 46 of ammonia as a pH adjusting agent and hydrazine as a deoxidizing agent. A predetermined amount of ammonia is injected into the water supply for adjusting the pH from the chemical injection means 45 so that the pH of the water supply in the low-pressure drum 32 is 9.0 or higher and the ammonia concentration is 0.5 ppm or higher.

Generally, when the pH of the feed water is less than 9.0, there is a concern that erosion / corrosion (corrosion / erosion) due to flow occurs. For this reason, the pH of the feed water in the low-pressure drum 32 is set to 9.0 or more. The pressure of the feed water in the low-pressure drum 32 is lower than the pressure of the feed water in the high-pressure drum 12 and the intermediate-pressure drum 22, and ammonia is more likely to evaporate. Since the distribution ratio between the gas phase and the liquid phase is high, the pH of the feed water in the low-pressure drum 32 is set to 9.0 or more so that the pH of the feed water in the high-pressure drum 12 and the intermediate pressure drum 22 is 9.0. Can also be high. Moreover, as the chemical | medical agent 47 of the high pressure drum 12, the intermediate pressure drum 22, and the low pressure drum 32, since ammonia tends to volatilize, sodium phosphate is used from the point of preventing pH fall.
In addition, the standard of pH of water supply and boiler water is defined in JIS (nonpatent literature 1).

JP 2002-180804 A JP-A-5-264492) JIS B8223-1999

By the way, in recent years, high-temperature high-pressure water supply to high-pressure drums has been performed due to the improvement of operation efficiency. As a result, the flow rate of water supply is large and the pressure is high. What has a wide control range of a water supply control valve (not shown) is required.
Therefore, as the high-pressure water supply control valve for controlling the high-temperature and high-pressure water supply, for example, a perforated plate single-stage water supply control valve 100A having a single-stage perforated plate for adjusting the amount of feed water shown in FIG. A multi-stage perforated plate multi-stage water supply control valve 100B or the like is used. However, when continuously operating, the differential pressure becomes high, and the iron component dissolved in the high-temperature high-pressure water supply 101 is the valve. There are cases where it adheres to the hole and as a result exceeds 90% of the valve opening.

  The multistage structure of the perforated plate constituting the perforated plate multistage water supply control valve 100B will be described with reference to FIGS. As shown in FIG. 11 to FIG. 13, the multi-stage structure of the perforated plate is formed by multi-layered segment plates 111 having a plurality of holes 110 opened, and a plug 112 is inserted into the central portion thereof to control the flow rate of fluid. It is adjusted. FIG. 13 schematically shows the configuration of the segment plate 111 and shows how the high-temperature and high-pressure water supply 101 passes through the plurality of holes 110.

A phenomenon in which the dissolved iron component is precipitated is shown in FIG. As shown in FIG. 14, in the pipe 102 through which the high-temperature high-pressure water supply 101 supplied from the high-pressure economizer 14 flows, iron ions dissolved in the economizer 14 provided on the upstream side exist. However, since the iron ions are in an unstable state, a sudden pressure drop occurs in the orifice portion 103 of the hole such as a perforated plate, and the dissolved ions (Fe ^{n +} ) dissolved in the high-temperature high-pressure feed water 101 Iron oxide crystals (Fe ₃ O ₄ ) 104 are deposited as a barrier. The deposited crystal 104 becomes a scale and closes the hole. As a result, the flow rate is lowered, so that the opening of the valve is opened according to the degree of adhesion of the scale.

  In particular, as shown in the relationship diagram between the flow path and pressure of the perforated plate multi-stage water supply control valve in FIG. 15, in the perforated plate multi-stage water supply control valve 100B, the pressure drop on the upstream (inlet) side is large and the scale easily adheres. It becomes. When the upstream side is closed, the flow rate region is reached, and the valve opening is gradually increased, so that the scale adhesion of the downstream side porous plate also proceeds.

As shown in FIG. 16 showing the relationship between water temperature and iron solubility at pH 9.3, the solubility of iron reaches its maximum when the temperature of the high-temperature high-pressure feed water is 200 ° C. It becomes a dissolved state by supersaturation. In this case, in the equilibrium theory, there is a possibility of scale deposits, in the case of the flow rate is slow (~3m / s) state of the pipe having a larger diameter as shown in Figure 14, collapsed its equilibrium state There is almost no generation of scale. However, the valve orifice portion 103 locally has a high flow velocity, a sudden pressure drop occurs, and crystal precipitation occurs due to kinetic factors.

  As shown in FIG. 16, when the temperature is about 220 ° C., when 1.7 ppb of iron is dissolved in the high-temperature water supply becomes 350 ° C. or higher at the outlet of the high-pressure economizer 14, Since only 3 ppb can be dissolved, the difference of 1.4 ppb is in a supersaturated state and there is a possibility of scale precipitation in equilibrium.

  For this reason, as shown in FIG. 17, when a scale adheres to the hole of the valve, maintenance is required when the feed water control valve opening reaches 90%, but maintenance costs increase, so the number of maintenance is reduced. There is a request to do. In particular, if maintenance is performed at the same time as periodic inspections of power generation facilities (power generation plants), inspections and inspections can be performed at the same time, which improves the plant operating rate, which is preferable but not yet realized. It is.

  In particular, in order to cope with the prolonged operation of the combined cycle plant, the appearance of a technique for reducing the scale adhesion rate in the high-pressure feed water control valve is eagerly desired.

  In view of the above problems, an object of the present invention is to provide a turbine equipment, an exhaust heat recovery boiler apparatus, and a method for operating the turbine equipment that can significantly reduce the scale adhesion rate of the high-pressure feed water control valve.

A first invention of the present invention for solving the above-mentioned problems includes a steam turbine that is operated by steam generated through a plurality of stages of different pressure units, a condenser that condenses the exhaust of the steam turbine, and In a turbine facility comprising a water supply system for supplying condensate condensed in the condenser to the exhaust heat recovery boiler side, the high-temperature high-pressure water supplied to the high-pressure drum of the high-pressure heating unit is controlled in the heating unit A chemical injection means for supplying ammonia and hydrazine to the supply water supplied to the high pressure water supply control valve, and an ammonia injection portion for injecting ammonia between the high pressure economizer and the high pressure water supply control valve of the high pressure heating unit in the heating unit And the medicine injection means injects ammonia and hydrazine into the water supply to set the pH of the water supply to 9.8 or higher and the hydride in the water supply. The Rajin concentration to be not more than 1 ppb, further wherein ammonia is injected from the ammonia injection section, is the iron ions that are dissolved in the water supply to the turbine equipment, characterized in that to precipitate as crystal particles of iron oxide.

A second invention is the turbine equipment according to the first invention, wherein the temperature of the high-temperature high-pressure feed water supplied to the high-pressure drum is 250 ° C. or higher.

A third invention is the turbine equipment according to the first or second invention, wherein the high-pressure feed water control valve is a perforated plate multi-stage feed water control valve.

A fourth invention is the turbine equipment according to any one of the first to third inventions, wherein the heat from the heat source is a combined plant that is exhaust gas gas.

According to a fifth aspect of the present invention, there is provided an exhaust heat recovery boiler that includes a high-pressure side unit that generates high-pressure side steam and a low-pressure side unit that generates low-pressure side steam and recovers heat from a heat source to generate high-pressure side steam and low-pressure side steam. In the exhaust heat recovery boiler apparatus comprising: a water supply system for supplying water to the exhaust heat recovery boiler; ammonia and hydrazine are supplied to the supply water supplied to the high pressure water supply control valve for controlling the high temperature and high pressure water supply supplied to the high pressure drum of the high pressure side unit. A medicine injection means for supplying, and an ammonia injection section for injecting ammonia between the high-pressure economizer and the high-pressure water supply control valve of the high-pressure side unit, and the medicine injection means includes ammonia and hydrazine in the water supply. The pH of the feed water is adjusted to 9.8 or more, the hydrazine concentration in the feed water is set to 1 ppb or less, and Ammonia was injected from the pneumoniae injection unit, there iron ions are dissolved in said water in exhaust heat recovery boiler and wherein the precipitating as crystal particles of iron oxide.

A sixth invention is the exhaust heat recovery boiler apparatus according to the fifth invention, wherein the temperature of the high-temperature high-pressure feed water supplied to the high-pressure drum is 250 ° C. or higher.

A seventh invention is the exhaust heat recovery boiler apparatus according to the fifth or sixth invention, wherein the high-pressure feed water control valve is a perforated plate multi-stage feed water control valve.

An eighth invention is the exhaust heat recovery boiler apparatus according to any one of the fifth to seventh inventions, wherein the heat from the heat source is a combined plant that is exhaust of a gas turbine.

A ninth aspect of the present invention relates to a steam turbine that is operated by steam generated through a plurality of stages of different pressure units, a condenser that condenses exhaust from the steam turbine, and condensate condensed in the condenser. In the operation method of the turbine equipment comprising a water supply system that supplies to the exhaust heat recovery boiler side, water supply that is supplied to a high-pressure water supply control valve that controls high-temperature high-pressure water supply that is supplied to the high-pressure drum of the high-pressure heating unit in the heating unit A chemical injection step of supplying ammonia and hydrazine to the gas, and an ammonia injection step of injecting ammonia between a high pressure economizer and a high pressure water supply control valve of the high pressure heating unit in the heating unit, The injecting step injects ammonia and hydrazine into the water supply to adjust the pH of the water supply to 9.8 or higher and the hydrazine concentration in the water supply to 1 ppb or lower. To so that the ammonia injection step is further the water supply ammonia was injected, the operation of the turbine iron ions are dissolved in the water, characterized in that driving while precipitated as crystal particles of iron oxide facility Is in the way.

  According to the present invention, by increasing the ammonia concentration to a pH of 9.8 or higher, scale adhesion on the high-pressure water supply control valve is reduced, and the number of maintenance can be reduced.

  In addition, by setting the hydrazine concentration to 1 ppb or less, generation of hydrogen can be suppressed, solubility of iron oxide by hydrogen can be suppressed, adhesion of scale in the high-pressure water supply control valve can be reduced, and the number of maintenance can be reduced. .

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

A turbine facility provided with an exhaust heat recovery boiler apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a turbine facility including an exhaust heat recovery boiler apparatus according to an embodiment. In addition, about the structure same as the turbine equipment provided with the waste heat recovery boiler apparatus which concerns on the prior art shown in FIG. 9, the same code | symbol is attached | subjected and description is abbreviate | omitted.
As shown in FIG. 1, the turbine equipment provided with the exhaust heat recovery boiler apparatus according to the present embodiment generates steam through the high pressure heating unit 3, the intermediate pressure heating unit 4, and the low pressure heating unit 5 by heat from the heat source. An exhaust heat recovery boiler 2 to be operated, a steam turbine 6 operated by steam of the exhaust heat recovery boiler 2, a condenser 8 for condensing exhaust gas from the steam turbine 6, and a condensate 50 condensed in the condenser 8. In a turbine facility comprising a water supply system that feeds the waste water to the exhaust heat recovery boiler 2 side via the condensate line L ₀ , means for injecting ammonia as a medicine 46 a into the condensate line L ₀ that supplies the condensate 50 The pH of the feed water supplied from 45 and circulating through the feed water system is 9.8 or more.

  FIG. 2 shows a schematic diagram of a portion of the high-pressure heating unit 3 in FIG. As shown in FIG. 2, the high-temperature high-pressure feed water 101 supplied from the high-pressure feed water pump 42 becomes 350 ° C. or higher by passing through the high-pressure economizer 14 and is supplied to the high-pressure drum 12 through the high-pressure feed water control valve 51. The high-pressure water supply is adjusted.

In this embodiment, the injection amount of ammonia in the medicine 46a injected by the medicine injection means 45 is increased so that the pH becomes 9.8 or more.
The ammonia supplied from the ammonia feeder may be any of ammonia gas, ammonia stock solution, or ammonia dilution solution.

FIG. 3 shows the relationship between water and iron solubility when the ammonia concentration is changed from the current pH 9.3 to pH 9.8.
As shown in FIG. 3, when the pH is 9.8, the iron supersaturation in the feed water is relaxed as the pH is increased, and the precipitation of scale can be suppressed in an equilibrium manner.
As shown in FIG. 3 , when the temperature is about 220 ° C., at pH 9.3, 1.7 ppb of iron dissolved in the high temperature water supply is increased to pH 9.8. .6 ppb is dissolved, and when the solubility at the outlet of the high pressure economizer 14 is 350 ° C. or higher is 0.3 ppb, the difference becomes 0.4 ppb in a supersaturated state, resulting in a pH of 9. This is because only one third of 1.4 ppb of the difference of 3 is in a supersaturated state, so that the possibility of scale precipitation is small in equilibrium.
Thus, in the case where the temperature of the high-temperature high-pressure feed water is 250 ° C. or higher, and further 300 ° C. or higher, scale precipitation can be suppressed by increasing the pH concentration.

  Therefore, as shown in the relationship diagram between the plant operation time and the feed water control valve opening in FIG. 4, the increase in the valve opening can be suppressed, so that the operation time can be prolonged, It is possible to perform the valve maintenance at the same time. Thereby, the plant operating rate can be significantly improved.

In this way, by improving the ammonia concentration in the feed water and setting the pH from 9.3, which is the conventional JIS standard value, to 9.8 or more, the solubility of iron is reduced, and the high-pressure feed water control valve has a hole. The amount of iron oxide that adheres is reduced. This reduces the amount of scale adhesion in the holes of the high-pressure water supply control valve, prolongs the time when the water supply control valve opening is 90% when scale adheres to the valve holes, and reduces the frequency of maintenance . To reduce the maintenance cost.
The high-pressure water supply control valve according to the present invention is not particularly limited, but the high-pressure water supply control using the perforated plate single-stage water supply control valve and the perforated plate multi-stage water supply control valve shown in FIGS. It is particularly suitable for use as a countermeasure for valves.

FIG. 5 is a schematic diagram of the high-pressure heating unit portion shown in FIG. 1 according to the present embodiment. As shown in FIG. 5, the injection amount of hydrazine in the drug 46b injected by the drug injection means 45 is extremely reduced so that its concentration is 1 ppb or less.
Thus, by reducing the hydrazine concentration, the dissolved hydrogen is reduced, and as a result, the iron solubility is reduced.

That is, hydrazine injected as a pipe corrosion inhibitor generates hydrogen as shown below by thermal decomposition.
2N ₂ H ₄ → 2NH ₃ 2 + N ₂ + H ₂

Here, FIG. 6 and FIG. 7 show the relationship between the temperature of the high-temperature high-pressure feed water and the solubility of iron when the hydrogen concentration in the feed water is changed. FIG. 6 is a relationship diagram of temperature and iron solubility when the pH is changed in increments of 0.2 from pH 9.0 to pH 9.8 when the hydrogen concentration is 10 ppb. FIG. 7 is a graph showing the relationship between temperature and iron solubility when the pH is changed in increments of 0.2 from pH 9.0 to pH 9.8 when the hydrogen concentration is 1 ppb.
As is apparent from FIGS. 6 and 7, it was found that when the hydrogen concentration is reduced from 10 ppb to 1 ppb, the solubility of iron becomes extremely low.
Therefore, since the lower hydrogen in the feed water has the effect of lowering the solubility of iron, the concentration of hydrazine 43b is lowered to 1 pb or less.
Hydrazine is defined as a deoxygenating agent in JIS with a concentration of 10 ppb or more. This is to maintain dissolved oxygen in feed water at 7 ppb or less, but in recent years, leakage in plants has also occurred. In addition, since there is no mixing of dissolved oxygen, the operation is not hindered even when the hydrazine concentration is reduced.
Therefore, since the iron solubility is reduced by setting the hydrazine concentration to 1 ppb or less, the amount of iron generated attached to the high-pressure water supply control valve 51 can be reduced, and the amount of scale attached to the valve can be reduced.

Further, as shown in FIGS. 6 and 7, since the pH in the feed water is particularly reduction effect than 9.8 or higher, with a the pH 9.8 or more by an increase in ammonia concentration, hydrazine 43b Concentration Due to the synergistic effect of the combined use of 1 ppb or less, the amount of iron generated on the high-pressure water supply control valve 51 can be further reduced, and the amount of scale attached to the valve can be reduced.

  FIG. 8 shows a schematic diagram of the high-pressure heating unit portion shown in FIG. 1 according to the present embodiment. As shown in FIG. 8, in Example 3, further, ammonia as the medicine 43 a is further injected between the high-pressure economizer 14 and the high-pressure feed water control valve 51 by the chemical injection means 45, and the high-pressure economizer 14 With respect to the iron ions generated in, the particles are positively precipitated as particles by raising the pH. The deposited particles pass through the hole of the valve, so there is no problem of scale adhesion.

  That is, instead of causing the scale to adhere to the barrier through the plurality of holes of the valve, particles are positively made visible inside the pipe to prevent the scale from adhering due to the generation of the scale in the orifice portion.

The ammonia 46a to be supplied is preferably injected so that the pH is 9.5 or higher, preferably 9.8 or higher, which is higher than the current pH value of 9.3.
In order to actively precipitate iron oxide particles between the high pressure economizer 14 and the high pressure water supply control valve 51, the pH 9.5 is 1.5 ppm, the pH 9.6 is 2.2 ppm, and the pH 9. It is necessary to inject about 5.0 ppm at 8 and about 12 ppm at pH 10.
In the drainage discharged from the plant, the pH may be adjusted separately so as to meet the drainage standard.

As described above, the turbine equipment of the present invention includes a steam turbine that is operated by steam generated through a plurality of stages of different pressure units, a condenser that condenses the exhaust of the steam turbine, and a condenser. High pressure water supply control valve for controlling high-temperature high-pressure water supply to be supplied to the high-pressure drum of the high-pressure heating unit within the heating unit in a turbine facility comprising a water supply system for supplying the condensate condensed in step 1 to the exhaust heat recovery boiler side A chemical injection means for supplying ammonia and hydrazine to the feed water supplied to the water supply , and an ammonia injection section for injecting ammonia between the high pressure economizer of the high pressure heating unit and the high pressure water supply control valve in the heating unit. The medicine injection means injects ammonia and hydrazine into the water supply to set the pH of the water supply to 9.8 or higher, and the hydrazine in the water supply. The concentration be equal to or smaller than 1 ppb, further ammonia was injected from the ammonia injection section, because the precipitating iron ions are dissolved in the said water supply as a crystalline iron oxide particles, the adhesion of scale in the high pressure feed water control valve And the number of maintenance can be reduced.

  In addition, since the heat from the heat source is a combined plant that is the exhaust of the gas turbine, the combined plant that combines the gas turbine and the steam turbine eliminates the problem of scale adhesion of the high-pressure feedwater control valve and continues for a long period of time. Driving.

The exhaust heat recovery boiler apparatus of the present invention comprises a high-pressure side unit that generates high-pressure side steam and a low-pressure side unit that generates low-pressure side steam, and recovers heat from a heat source to generate high-pressure side steam and low-pressure side steam. a heat recovery boiler, a water supply system for supplying water to the exhaust heat recovery boiler, in the exhaust heat recovery boiler apparatus consisting, in water supplies to the high pressure feed water control valve for controlling the high-temperature high-pressure feed water supplied to the high-pressure drum of the high pressure side unit A chemical injection means for supplying ammonia and hydrazine; and an ammonia injection section for injecting ammonia between the high-pressure economizer and the high-pressure water supply control valve of the high-pressure side unit; Inject ammonia and hydrazine into the feed water so that the pH of the feed water is 9.8 or more and the hydrazine concentration in the feed water is 1 ppb or less. Further wherein the ammonia is injected from the ammonia injection section, because the precipitating iron ions are dissolved in the said water supply as a crystalline iron oxide particles, and deposition of scale reduction in the high-pressure feed water control valve, reducing the number of maintenance It becomes possible to do.

The water treatment method of the present invention includes a steam turbine that is operated by steam generated through a plurality of stages of different pressure units, a condenser that condenses the exhaust of the steam turbine, and a condenser that is condensed in the condenser. In a method for operating a turbine facility comprising a water supply system that supplies water to the exhaust heat recovery boiler side, supply to a high-pressure water supply control valve that controls high-temperature high-pressure water supply supplied to the high-pressure drum of the high-pressure heating unit in the heating unit A chemical injection step of supplying ammonia and hydrazine to the feed water , and an ammonia injection step of injecting ammonia between the high pressure economizer of the high pressure heating unit and the high pressure feed water control valve in the heating unit, In the chemical injection step, ammonia and hydrazine are injected into the water supply so that the pH of the water supply is 9.8 or higher, and the hydrazine concentration in the water supply is 1 pp. As the following, the ammonia injection step, since further ammonia was injected into the water supply is operated while precipitated iron ions are dissolved in the said water supply as a crystalline iron oxide particles, in the high-pressure feed water control valve Scale adhesion is reduced, and the number of maintenance can be reduced.

  As described above, according to the present invention, scale adhesion in the high-pressure feed water control valve is reduced, the number of maintenance can be reduced, and continuous operation of the turbine equipment becomes possible.

It is the schematic which shows the turbine installation provided with the waste heat recovery boiler apparatus which concerns on Example 1. FIG. FIG. 2 is a schematic diagram of a high-pressure heating unit portion in FIG. 1 according to Example 1. It is a related figure of water and iron solubility at the time of changing from pH9.3 to pH9.8. It is a related figure of plant operation time and feed water control valve opening. FIG. 3 is a schematic diagram of a high-pressure heating unit portion in FIG. 1 according to a second embodiment. It is a related figure of temperature and iron solubility when changing pH when hydrogen concentration is 10 ppb. It is a related figure of temperature and iron solubility when changing pH when hydrogen concentration is 1 ppb. It is a schematic diagram of the high-pressure heating unit part of FIG. It is a whole system schematic diagram of turbine equipment provided with a waste heat recovery boiler device. It is a schematic diagram of a perforated plate single-stage water supply control valve. It is a schematic diagram of a perforated plate multistage water supply control valve. It is a block diagram of the perforated plate which comprises a perforated plate multistage water supply control valve. FIG. 3 is a partially cutaway structural view of a perforated plate constituting a perforated plate multistage water supply control valve. It is a scale adhesion schematic diagram of a high-pressure water supply control valve. It is a related figure of the flow path and pressure of a perforated plate multistage water supply control valve. It is a related figure of water and iron solubility in pH9.3. It is a related figure of the plant operation time and feed water control valve opening degree in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Waste heat recovery boiler 3 High pressure heating unit 4 Medium pressure heating unit 5 Low pressure heating unit 6 Steam turbine 7 Water supply line 8 Condenser 9 Condensate pump 10 Deaerator 11 High pressure superheater 12 High pressure drum 13 High pressure evaporator 14 High pressure economizer 45 Chemical injection means 46 Chemical 46a Ammonia 46b Hydrazine 50 Condensate 51 High pressure water supply control valve 100A Perforated plate single stage water supply control valve 100B Perforated plate multistage water supply control valve 101 High temperature high pressure water supply 103 Orifice 104 Crystal (Fe ₃ O ₄ )

Claims (9)

A steam turbine that is activated by steam generated through heating units with different pressures in multiple stages, a condenser that condenses the exhaust of the steam turbine, and the condensate condensed in the condenser is placed on the exhaust heat recovery boiler side. In turbine equipment consisting of a feed water system
A chemical injection means for supplying ammonia and hydrazine to the feed water supplied to the high-pressure feed water control valve for controlling the high-temperature and high-pressure feed water supplied to the high-pressure drum of the high-pressure heating unit in the heating unit ;
An ammonia injection part for injecting ammonia between the high pressure economizer of the high pressure heating unit and the high pressure feed water control valve in the heating unit;
Have
The medicine injection means injects ammonia and hydrazine into the water supply so that the pH of the water supply is 9.8 or higher, the hydrazine concentration in the water supply is 1 ppb or lower, and further from the ammonia injection section. A turbine equipment characterized by injecting ammonia and precipitating iron ions dissolved in the feed water as iron oxide crystal particles . In claim 1 ,
Turbine equipment characterized in that the temperature of the high-temperature high-pressure feed water supplied to the high-pressure drum is 250 ° C. or higher. In claim 1 or 2 ,
The high-pressure water supply control valve is a perforated plate multi-stage water supply control valve. In any one of Claims 1 thru | or 3 ,
A turbine facility characterized in that the heat from the heat source is a combined plant that is exhaust of a gas turbine. Exhaust heat recovery boiler that consists of a high-pressure side unit that generates high-pressure side steam and a low-pressure side unit that generates low-pressure side steam to recover heat from the heat source and generate high-pressure side steam and low-pressure side steam, and an exhaust heat recovery boiler In an exhaust heat recovery boiler device comprising a water supply system for supplying water,
A chemical injection means for supplying ammonia and hydrazine to the feed water supplied to the high-pressure feed water control valve for controlling the high-temperature and high-pressure feed water supplied to the high-pressure drum of the high-pressure side unit ;
An ammonia injection part for injecting ammonia between the high-pressure economizer of the high-pressure side unit and the high-pressure feed water control valve;
Have
The medicine injection means injects ammonia and hydrazine into the water supply so that the pH of the water supply is 9.8 or higher, the hydrazine concentration in the water supply is 1 ppb or lower, and further from the ammonia injection section. An exhaust heat recovery boiler apparatus in which ammonia is injected and iron ions dissolved in the water supply are precipitated as iron oxide crystal particles . In claim 5 ,
The exhaust heat recovery boiler apparatus, wherein the temperature of the high-temperature high-pressure feed water supplied to the high-pressure drum is 250 ° C or higher. In claim 5 or 6 ,
The exhaust heat recovery boiler apparatus, wherein the high-pressure feed water control valve is a perforated plate multi-stage feed water control valve. In any one of Claims 5 thru | or 7 ,
An exhaust heat recovery boiler apparatus characterized in that the heat from the heat source is a combined plant that is exhaust of a gas turbine. A steam turbine that is activated by steam generated through heating units with different pressures in multiple stages, a condenser that condenses the exhaust of the steam turbine, and the condensate condensed in the condenser is placed on the exhaust heat recovery boiler side. In the operation method of the turbine equipment consisting of the water supply system to supply,
A chemical injection step of supplying ammonia and hydrazine to the feed water supplied to the high-pressure feed water control valve for controlling the high-temperature and high-pressure feed water supplied to the high-pressure drum of the high-pressure heating unit in the heating unit ;
An ammonia injection step of injecting ammonia between the high pressure economizer of the high pressure heating unit and the high pressure feed water control valve in the heating unit;
Have
In the chemical injection step, ammonia and hydrazine are injected into the water supply so that the pH of the water supply is 9.8 or more and the hydrazine concentration in the water supply is 1 ppb or less,
The method for operating a turbine facility, wherein the ammonia injection step is further performed by injecting ammonia into the feed water and depositing iron ions dissolved in the feed water as iron oxide crystal particles .

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