JP2013076520A - Method of eliminating iron component in heater drain water in power generating plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of eliminating an iron component in heater drain water in a power generating plant, the method being capable of reducing iron concentration in water supply fed to a boiler to a reference value or below.SOLUTION: If iron ion concentration in heater drain water 117 discharged from a heater drain tank 116 is higher than a predetermined value, the heater drain water 117 is discharged from the system, if iron ion concentration in the heater drain water 117 discharged from the heater drain tank 116 is the predetermined value or below, the heater drain water 117 is supplied to a filtration device 15, or if previously set predetermined time has not elapsed, the heater drain water 117 is discharged outside the system, and if the previously set predetermined time has elapsed, the heater drain water 117 is supplied to the filtration device 15.

Description

  The present invention relates to a method for removing iron components in heater drain water in a power plant, by filtering iron components in heater drain water fed from a feed water heater, and making the heater drain water recoverable in a water supply pipe at all times. .

  Conventionally, in a thermal power plant, generated high-temperature and high-pressure steam is supplied to a turbine, and the turbine is driven by this steam to generate power. The steam after driving the turbine is cooled by the condenser and returned to the water state, then heated again, supplied to the boiler, and reused.

  By the way, the feed water to the boiler contains impurities mainly composed of iron oxide, and these impurities gradually adhere to the inner surface of the heat transfer tube of the boiler, and this deposit may increase the differential pressure of the boiler. In other words, there is a risk of damage to boilers and piping. For this reason, it is practiced to remove impurities mainly composed of iron oxide by installing an iron removal filter in the flow path through which the water supply of the water supply system flows (Patent Document 1).

Various filters such as cartridges, hollow fibers, and electromagnetic filters have been proposed as a method for removing iron components. However, since the iron oxide particles are extremely fine, the impurity removal performance of these filters is unstable. However, it has not been put into practical use (Patent Document 2).
Furthermore, the JIS standard specifies that the iron concentration in the feed water at the boiler inlet is 5 μg / l (ppb) or less, preferably 2 μg / l (ppb) or less (Non-patent Document 1).

JP 2001-17983 A Japanese Patent Laid-Open No. 11-57416

JIS B 8223 (Boiler water supply and boiler water quality), issued on October 20, 2006

However, heater drain water containing a large amount of iron or the like exceeding the reference value must be discharged outside the system, and cannot be returned to the water supply system for reuse. Therefore, as a result of operating the power generation output at about 60 to 80% in order to supply new feed water to the boiler, a large amount of water (pure water) is required and the power generation output of the turbine equipment is increased to 100%. It takes 3 days to complete.
In addition, there is a problem that wastewater treatment equipment for treating a large amount of wastewater discharged outside the system and a pure water production facility for producing a large amount of water (pure water) are required, resulting in an increase in equipment costs. It was.

  The present invention has been made to solve the above-described problems, and provides a method for removing iron components in heater drain water in a power plant, which can reduce the iron concentration in feed water supplied to a boiler to a reference value or less. The purpose is to do.

The present invention employs the following means in order to solve the above problems.
A method for removing iron components in heater drain water in a power plant according to the present invention includes a boiler that generates steam by heat from a heat source, a steam turbine that operates with steam from the boiler, and condensates exhaust from the steam turbine. A condenser, a feed water system that feeds the condensed water condensed in the condenser to the boiler side as feed water, and a feed pipe of the feed water system, and is fed from the steam turbine to the reheater A part of the exhaust gas to be extracted is extracted and a water heater is used to heat the water supply, a heater drain tank to store heater drain water discharged from the water heater, and a filtration device for filtering iron particles in the heater drain water A method for removing iron components from heater drain water in a power plant, wherein oxygen treatment is performed by injecting oxygen into the water supply. When the iron ion concentration in the heater drain water discharged from the tadrain tank is higher than a predetermined value, the heater drain water is discharged out of the system, and the iron ion concentration in the heater drain water discharged from the heater drain tank Is less than or equal to a predetermined value, the heater drain water is supplied to the filtration device, or when the preset predetermined time has not elapsed, the heater drain water is discharged out of the system. The heater drain water is supplied to the filtration device when a predetermined time set in advance elapses.

  Further, the power plant according to the present invention includes a boiler that generates steam by heat from a heat source, a steam turbine that operates by steam of the boiler, a condenser that condenses exhaust gas from the steam turbine, and the condenser. A water supply system that feeds the condensed water condensed in the water supply to the boiler side as supply water, and a part of the exhaust gas that is interposed in the water supply pipe of the water supply system and that is supplied from the steam turbine to the reheater is extracted. And a water heater that heats the water supply using this, a heater drain tank that stores heater drain water discharged from the water heater, and a filtration device that filters iron particles in the heater drain water, and A power plant that performs oxygen treatment by injecting oxygen into feed water, wherein the iron ion concentration in the heater drain water discharged from the heater drain tank is higher than a predetermined value. The heater drain water is discharged outside the system, and when the iron ion concentration in the heater drain water discharged from the heater drain tank is below a predetermined value, the heater drain water is supplied to the filtration device. Alternatively, when the preset predetermined time has not elapsed, the heater drain water is discharged out of the system, and when the preset predetermined time has elapsed, the heater drain water is supplied to the filtration device. Is done.

According to the method for removing iron components from heater drain water in the power plant according to the present invention and the power plant according to the present invention, when the iron ion concentration in the heater drain water discharged from the heater drain tank is higher than a predetermined value, the heater drain When water is discharged out of the system and the iron ion concentration in the heater drain water discharged from the heater drain tank is below a predetermined value, the heater drain water is supplied to the filtration device, or a preset predetermined time has elapsed. If not, the heater drain water is discharged out of the system, and when a predetermined time has elapsed in advance, the heater drain water is supplied to the filtration device.
Here, the “predetermined value” is 10% of the boiler recovery rate of the power plant (the ratio of heater drain water out of the feed water flowing into the boiler), and the iron concentration in the feed water at the boiler inlet is in accordance with the JIS standard described above. When it is less than the strictest standard value (2 μg / l) specified, it becomes 20 (= 2 ÷ 0.1) μg / l.
Further, the “predetermined time” is a time (for example, 4 hours) required for the iron ion concentration in the heater drain water discharged from the heater drain tank to be a predetermined value or less, which is actually measured in the power plant. .
Thereby, the iron density | concentration in the feed water supplied to a boiler can be made below into the reference value prescribed | regulated to JIS specification.

  In the method for removing iron components in the heater drain water in the power plant, when the difference between the pressure at the inlet of the filtration device and the pressure at the outlet of the filtration device is equal to or higher than a predetermined pressure, bypass for bypassing the filtration device More preferably, the heater drain water is guided to the water heater through a pipe.

According to the method for removing the iron component in the heater drain water in such a power plant, when the differential pressure of the filtration device becomes a predetermined pressure (for example, 110 kPa) or more, the heater drain water is passed through a bypass pipe that bypasses the filtration device. It will be guided to the water heater.
Thereby, the amount of water supplied to the boiler can be secured.

  In the method for removing the iron component in the heater drain water in the power plant, when the heater drain water is guided to the feed water heater via a bypass pipe that bypasses the filtration device, the heater drain water is allowed to flow through the filtration device at a minimum flow rate. Further preferred.

According to the method for removing the iron component in the heater drain water in such a power plant, when the differential pressure of the filtration device becomes equal to or higher than a predetermined pressure (for example, 110 kPa), the heater drain water having the minimum flow rate is caused to flow through the filtration device. become.
Thereby, sticking of the iron particle collected by the filtration apparatus can be prevented.

  In the method for removing an iron component in heater drain water in the power plant, the heater drain water is passed through only the surface layer portion of the filter element constituting the filtration device to replace the water inside the container containing the filter element. It is more preferable to do so.

  According to the method for removing the iron component in the heater drain water in such a power plant, water is not passed through the filter element and iron is not collected, so that the filter element necessary for flowing the minimum flow rate (for example, 5t / H × Fe: 20 ppb (mg / t) × 24H × 365day = 876 g-filter element necessary to collect 876 g-Fe) can be eliminated.

  According to the method for removing iron components from heater drain water in the power plant according to the present invention, the iron concentration in the feed water supplied to the boiler can be reduced to a reference value or less.

It is a schematic structure figure of a power plant concerning one embodiment of the present invention. It is a systematic diagram which shows the principal part of the power plant concerning one Embodiment of this invention in detail. It is a figure which shows the outline of the filtration apparatus which concerns on one Embodiment of this invention, Comprising: (a) is a longitudinal cross-sectional view, (b) is a perspective view of a filter element. It is a figure which shows the outline of the filtration apparatus which concerns on other embodiment of this invention, Comprising: (a) is a longitudinal cross-sectional view, (b) is a top view of a filter element. It is a figure which shows the outline of the filtration apparatus which concerns on another embodiment of this invention, Comprising: (a) is a longitudinal cross-sectional view, (b) is a top view of a filter element. It is a figure which shows the outline of the filtration apparatus which concerns on another embodiment of this invention, Comprising: (a) is a longitudinal cross-sectional view, (b) is a perspective view of a filter element.

Hereinafter, a method for removing an iron component in heater drain water in a power plant according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 is a schematic configuration diagram of a power plant according to the present embodiment, and FIG. 2 is a system diagram showing in detail a main part of the power plant according to the present embodiment.
In addition, this invention is not limited by this embodiment. In addition, constituent elements in the present embodiment include those that can be easily assumed by those skilled in the art or that are substantially the same.

  As shown in FIG. 1, a power plant 10 according to this embodiment includes a boiler 118 that generates steam 11 by heat from a heat source, a steam turbine 12 that operates with the steam 11 of the boiler 118, and the steam turbine 12. A condenser 106 for condensing the exhaust gas of the boiler, a water supply system A for supplying the condensate condensed in the condenser 106 to the boiler 118 side as water supply 107, and a water supply pipe 13 of the water supply system A. A low-pressure feed water heater 109 that extracts a part of the exhaust gas fed from the steam turbine 12 to the reheater 115 as the extraction air 14 and heats the feed water 107 using this, and the low-pressure feed water heater 109, a low pressure heater drain tank 116 for storing the heater drain water 117 discharged from 109, and a filtration device 15 for filtering iron in the heater drain water 117; The iron ion concentration in the heater drain water 117 provided between the low pressure heater drain tank 116 and the filtration device 15 and discharged from the low pressure heater drain tank 116 is a predetermined value (20 μg / l in this embodiment). If it is higher, the heater drain water 117 is discharged out of the system, and when the iron ion concentration in the heater drain water 117 is below a predetermined value, the flow path is switched to supply to the filtration device 15 ( A second) flow path switching unit 16B.

  The predetermined value of the iron ion concentration in the heater drain water 117 is set to 20 μg / l because the boiler drain rate of the power plant 10 according to this embodiment (the heater drain of the feed water 107 flowing into the boiler 118 is This is because the ratio of water 117 is 10%. That is, in order to make the iron concentration in the feed water at the boiler inlet equal to or less than the strictest standard value (2 μg / l) defined in the above-mentioned JIS standard, the predetermined value of the iron ion concentration in the heater drain water 117 is 20 ( = 2 ÷ 0.1) μg / l. Therefore, when the boiler recovery rate of the power plant 10 is 5%, the predetermined value of the iron ion concentration in the heater drain water 117 is 40 μg / l.

In this embodiment, the iron ion concentration in the heater drain water 117 is calculated as follows. Here, the iron ion refers to fine iron that cannot be collected by the filtration device 15, and has a particle diameter of 0.1 μm or less, for example.
First, the same amount of sample water I for analysis of total iron (iron particles + iron ions) and sample water II for analysis of iron particles are collected from the low-pressure heater drain tank 116.
Next, the total iron amount contained in the sample water I for total iron analysis is measured using an absorptiometry or the like.
Subsequently, sample water II for iron particle analysis is passed through a filter having a pore diameter of 0.1 μm, and the amount of iron particles collected on the filter is measured using an absorptiometry or the like.
Then, the amount of iron ions is obtained by subtracting the amount of iron particles from the total amount of iron.
The iron ion concentration in the heater drain water 117 is calculated by dividing the mass of iron ions by the volume of the sample water.

  Here, in the power plant 10 according to the present embodiment, condensate is obtained by the condenser 106 disposed on the downstream side of the steam turbine 12, and makeup water 105 from a makeup water tank 104 provided outside is obtained. Is mixed with the condensate as necessary and supplied to the feed water system A as feed water 107 for circulation.

  In the water supply system A according to the present embodiment, the condensate pump 18, the electromagnetic filter 19, the pure water device 20, and the condensate booster pump 21 are disposed between the condenser 106 and the low-pressure feed water heater 109. A deaerator 110, a storage tank 111, and a boiler feed pump 22 are interposed in the water supply pipe 13 between the low pressure water heater 109 and the high pressure water heater 112. .

  Further, the feed water 107 heated in the low-pressure feed water heater 109 is further heated in the high-pressure feed water heater 112 using high temperature / high pressure bleed air (not shown). The water supply 107 heated through the high-pressure water heater 112 is supplied to the boiler 118.

  Here, in the present embodiment, the heater drain water 117 discharged from the low-pressure feed water heater 109 that heats the feed water 107 is stored in the low-pressure heater drain tank 116, and the low-pressure heater drain pump 23 performs the low-pressure heater drain tank 23. 116 is discharged to the filtration device 15.

  Then, based on the measurement result of the iron ion concentration in the heater drain water 117 calculated from the sample waters I and II, it is determined whether or not the iron ion concentration is a predetermined value or less. As a result of the determination, when the iron ion concentration in the heater drain water 117 is higher than a predetermined value, the flow path switching unit 16B switches the flow path, discharges the heater drain water 117 out of the system, and the predetermined value. In the following cases, the iron particles in the heater drain water 117 are removed by supplying to the filtration device 15.

  In this embodiment, when the iron ion concentration in the heater drain water 117 is equal to or lower than a predetermined value, the flow path switching unit 16A switches the flow path, and supplies the heater drain water 117 to the condenser 106. You may make it circulate through the inside of the water supply system A. FIG.

  Here, in this embodiment, when the iron ion concentration in the said heater drain water 117 is below a predetermined value, an iron particle is filtered by the said filtration apparatus 15, and it supplies to the said water supply pipe | tube 13 side of the said water supply system A. The heater drain water 117 to be mixed is drain filtered water 117A, and the heater drain water 117 supplied as recycled water to the condenser 106 side is drain feed water 117B.

In this embodiment, when the predetermined value of the iron ion concentration in the heater drain water 117 is 20 μg / l or less, the drain water supply 117B is supplied to the condenser 106 to circulate in the water supply system A. Like that. This is because, for example, when the drain water supply 117B is supplied to the condenser 106 as reused water, the device provided in the water supply system A is not contaminated by iron particles or the like in the heater drain water 117. It is to do.
Further, when the drain water 117B is supplied to the condenser 106, iron is further removed by a condensate treatment device (filter and condensate demineralizer) (not shown) installed on the downstream side thereof to the system. Since it is collected, water can be saved.

In the present embodiment, the predetermined value of the iron ion concentration in the heater drain water 117 is set to 20 μg / l. However, the present invention is not limited to this, and the loosest standard defined in the JIS standard described above. When the value (5 μg / l) or less is set, the predetermined value of the iron ion concentration in the heater drain water 117 may be 50 μg / l.
Moreover, the code | symbol 114 in FIG. 1 is a superheater.

As shown in FIGS. 1 and 2, the heater drain water 117 discharged from the low-pressure feed water heater 109 is guided to the low-pressure heater drain tank 116 via a (low-pressure feed water) drain main pipe 31.
When the iron ion concentration in the heater drain water 117 is equal to or lower than a predetermined value, the heater drain water 117 discharged from the low pressure heater drain tank 116 is guided to the filtration device 15 via the drain main pipe 31 and the filtration device. The drain filtered water 117 A, in which the iron particles are filtered by 15, is fed to the feed water pipe 13 side of the feed water system A through the drain main pipe 31 and mixed with the feed water 107 flowing through the feed water pipe 13.

Further, when the iron ion concentration in the heater drain water 117 is a predetermined value or less, the heater drain water 117 discharged from the low pressure heater drain tank 116 is branched at the flow path switching unit 16A (low pressure water heater) drain. It is also possible to use the drain water supply 117B that is led to the condenser 106 through the branch pipe 32 and supplied to the condenser 106 side as recycled water.
On the other hand, when the iron ion concentration in the heater drain water 117 is higher than a predetermined value, the heater drain water 117 discharged from the low-pressure heater drain tank 116 is discharged outside the system through the system blow pipe 33.

As shown in FIG. 2, in the power plant 10 according to the present embodiment, the drain main pipe 31 positioned between the flow path switching unit 16 </ b> B and the filtration device 15, the filtration device 15, and the low-pressure water supply A bypass pipe 34 communicating with the drain main pipe 31 located between the heater 109 is provided.
In addition, a drain main pipe 31 located between the flow path switching unit 16B and the filtration device 15 is provided with a minimum flow supply pipe 35, and between the filtration device 15 and the low-pressure feed water heater 109. And a minimum flow return pipe 36 that communicates with the drain main pipe 31 located between the low-pressure heater drain tank 116 and the flow path switching portion 16A.

Note that one end (upstream end) of the bypass pipe 34 is connected to a drain main pipe 31 located upstream from one end (upstream end) of the minimum flow supply pipe 35.
Further, when the heater drain water 117 discharged from the low-pressure heater drain tank 116 is guided to the filtration device 15 via the drain main pipe 31, it is between the flow path switching unit 16A and the flow path switching unit 16B. , The valve 41 provided between the flow path switching unit 16B and the filtration device 15, and the downstream side of the filtration device 15 and the other end (downstream end) of the bypass pipe 34. The valve 43 provided in the middle of the drain main pipe 31 located upstream from the joining portion (location) to which the pipe is connected is fully opened, and the valve 44 provided in the middle of the drain branch pipe 32 is provided. The valve 45 provided in the middle of the extra-system blow pipe 33, the valve 46 provided in the middle of the bypass pipe 34, and the valve 4 provided in the middle of the minimum flow supply pipe 35 , And a valve 48 provided in the middle of the minimum flow return pipe 36 each of which is fully closed.

  When the heater drain water 117 discharged from the low-pressure heater drain tank 116 is guided to the filtration device 15 via the drain main pipe 31, the pressure at the inlet of the filtration device 15 and the filtration device 15 When the difference from the pressure at the outlet (differential pressure of the filtration device 15) becomes a predetermined pressure (for example, 110 kPa) or more, or the iron ion concentration in the heater drain water 117 is 20 μg / l or less, and When the amount of iron particles at the outlet of the filtration device 15 becomes 0 μg / l, the valve 43 is switched from fully open to fully closed, the valve 46 is switched from fully closed to fully open, and the valves 47 and 48 are opened. Thus, the amount of water supplied to the boiler 118 is ensured and the heater drain water 117 flows into the filtration device 15 at a minimum flow rate. A large amount will be flown. Here, the minimum flow rate is based on the minimum value that can be measured with a flow meter, and is, for example, about 2% of the water flow rate to the filter.

  Here, the filtration device 15 used in the present embodiment needs to be usable for water conditions during normal operation of the low-pressure water heater 109. Therefore, as the filtration device 15 used in the present embodiment, for example, a pleated filter element having a pore diameter of 0.1 μm made of polysulfonic acid, polyvinylidene fluoride (PVDF), Kevlar (registered trademark), metal porous filter, or the like is used. However, the present invention is not limited to this.

According to the method for removing the iron component in the heater drain water in the power plant 10 according to the present embodiment, when the iron ion concentration in the heater drain water discharged from the heater drain tank 116 is higher than 20 μg / l, the heater drain water is a system. When the iron ion concentration in the heater drain water discharged to the outside and discharged from the heater drain tank 116 is 20 μg / l or less, the heater drain water is supplied to the filtration device 15.
Here, the “predetermined value” is 10% of the boiler recovery rate of the power plant (the ratio of heater drain water out of the feed water flowing into the boiler), and the iron concentration in the feed water at the boiler inlet is in accordance with the JIS standard described above. When it is less than the strictest standard value (2 μg / l) specified, it becomes 20 (= 2 ÷ 0.1) μg / l.
Thereby, the iron density | concentration in the feed water supplied to the boiler 118 can be made below into the strictest reference value prescribed | regulated by JIS specification.

Moreover, according to the removal method of the iron component in heater drain water in the power plant 10 which concerns on this embodiment, when the differential pressure | voltage of the filtration apparatus 15 becomes more than predetermined | prescribed pressure (for example, 110 kPa), the bypass which bypasses the filtration apparatus 15 The heater drain water 117 is guided to the low-pressure feed water heater 109 through the pipe 34.
Thereby, the amount of water supplied to the boiler 118 can be secured.

Furthermore, according to the method for removing the iron component from the heater drain water in the power plant 10 according to the present embodiment, when the differential pressure of the filtration device 15 becomes a predetermined pressure (for example, 110 kPa) or more, the heater drain water 117 having the minimum flow rate is obtained. Is passed through the filtration device 15.
Thereby, sticking of the iron particle collected by the filtration apparatus 15 can be prevented.

In addition, this invention is not limited to embodiment mentioned above, It can also implement by changing and changing suitably as needed.
For example, in the above-described embodiment, the heater drain water is passed through the filtration device 15 after the iron ion concentration in the heater drain water discharged from the heater drain tank 116 becomes 20 μg / l (predetermined value) or less.
However, the present invention is not limited to this, and the heater drain water may be passed through the filtration device 15 after a predetermined time has elapsed.
Here, the “predetermined time” is a time required for the iron ion concentration in the heater drain water discharged from the heater drain tank to be less than or equal to a predetermined value, which is actually measured in the power plant. For example, in the case of a plant with an output of 1000 MW, it takes about 2 hours from the generation of drain until the iron ion concentration becomes 20 μg / l (predetermined value) or less. Therefore, after 2 hours have passed, water flow to the filtration device 15 is started. Thus, the work efficiency can be improved by determining the water passage start time to the filtration device 15 from the actual value corresponding to the plant output in advance.

Moreover, in embodiment mentioned above, when the heater drain water 117 of the minimum flow is poured into the filtration apparatus 15, as shown to Fig.3 (a) and FIG.3 (b), it is made to continue the water flow to the filter element 15a. I have to.
However, the present invention is not limited to this, and as shown in FIGS. 4 (a) and 4 (b), water is passed only to the surface layer portion of the filter element 15a, and water is passed to the filter element 15a. And the water inside the container 15b of the filtration device 15 may be replaced.
In this case, since water is not passed through the filter element 15a and iron is not collected, the filter element 15a necessary for flowing the minimum flow rate (for example, 5t / H × Fe: 20 ppb (mg / t) × The filter element 15a) necessary for collecting 24H × 365day = 876 g-Fe can be eliminated.
In this case, a discharge pipe 15c that guides the heater drain water 117 that has been guided into the container 15b and passed through only the surface layer of the filter element 15a to the outside of the container 15b is required.

Further, in the embodiment shown in FIGS. 4 (a) and 4 (b), water is passed only to the surface layer portion of the filter element 15a, the water flow to the filter element 15a is interrupted, and the container 15b of the filtration device 15 is suspended. When replacing the water in the interior, as shown in FIGS. 5 (a) and 5 (b), an iron cleaning solution (citric acid, EDTA, etc.) is passed through the container 15b, and the filtration device 15 More preferably, the water inside the container 15b is replaced.
In this case, part of the iron oxide adhering to the surface layer portion of the filter element 15a is dissolved and removed from the surface layer portion of the filter element 15a by the iron cleaning liquid, thereby extending the life of the filter element 15a. Can be made.

Furthermore, in the embodiment shown in FIGS. 1 and 2, as shown in FIGS. 6 (a) and 6 (b), when the power plant 10 is in a standby state, pure water with the minimum flow rate is supplied to the filter element 15a. More preferably, the filter element 15a can be backwashed by passing water from the reverse direction.
In this case, the filter element 15a can be regenerated and the life of the filter element 15a can be extended.

DESCRIPTION OF SYMBOLS 10 Power plant 12 Steam turbine 13 Feed pipe 15 Filtration apparatus 15a Filter element 15b Container 34 Bypass pipe 106 Condenser 109 (Low pressure) Feed water heater 115 Reheater 116 Heater drain tank 117 Heater drain water 118 Boiler A Feed water system

Claims (5)

A boiler that generates steam by heat from a heat source;
A steam turbine operated by steam of the boiler;
A condenser for condensing exhaust from the steam turbine;
A water supply system that feeds the condensate condensed in the condenser as feed water to the boiler side;
A water heater that is interposed in a water supply pipe of the water supply system, bleeds a part of the exhaust gas that is supplied from the steam turbine to the reheater, and heats the water supply using this;
A heater drain tank for storing heater drain water discharged from the water heater;
A filtration device for filtering iron particles in the heater drain water;
And having
A method for removing iron components in heater drain water in a power plant, wherein oxygen treatment is performed by injecting oxygen into the feed water,
When the iron ion concentration in the heater drain water discharged from the heater drain tank is higher than a predetermined value, the heater drain water is discharged outside the system, and the heater drain water discharged from the heater drain tank When the iron ion concentration is below a predetermined value, the heater drain water is supplied to the filtration device,
Alternatively, when the preset predetermined time has not elapsed, the heater drain water is discharged out of the system, and when the preset predetermined time has elapsed, the heater drain water is supplied to the filtration device. A method for removing an iron component in heater drain water in a power plant, wherein the iron component is supplied to the power plant.   When the difference between the pressure at the inlet of the filtration device and the pressure at the outlet of the filtration device exceeds a predetermined pressure, the heater drain water is guided to the feed water heater via a bypass pipe that bypasses the filtration device. The method for removing an iron component from heater drain water in a power plant according to claim 1.   3. The power plant according to claim 2, wherein when the heater drain water is guided to the feed water heater via a bypass pipe that bypasses the filtration device, the heater drain water is allowed to flow through the filtration device at a minimum flow rate. A method for removing iron components from heater drain water.   4. The heater drain water is passed through only a surface layer portion of a filter element that constitutes the filtration device to replace water inside a container that accommodates the filter element. For removing iron components from heater drain water in Japanese power plants. A boiler that generates steam by heat from a heat source;
A steam turbine operated by steam of the boiler;
A condenser for condensing exhaust from the steam turbine;
A water supply system that feeds the condensate condensed in the condenser as feed water to the boiler side;
A water heater that is interposed in a water supply pipe of the water supply system, bleeds a part of the exhaust gas that is supplied from the steam turbine to the reheater, and heats the water supply using this;
A heater drain tank for storing heater drain water discharged from the water heater;
A filtration device for filtering iron particles in the heater drain water;
And having
A power plant that performs oxygen treatment by injecting oxygen into the water supply,
When the iron ion concentration in the heater drain water discharged from the heater drain tank is higher than a predetermined value, the heater drain water is discharged outside the system, and the heater drain water discharged from the heater drain tank When the iron ion concentration is below a predetermined value, the heater drain water is supplied to the filtration device,
Alternatively, when the preset predetermined time has not elapsed, the heater drain water is discharged out of the system, and when the preset predetermined time has elapsed, the heater drain water is supplied to the filtration device. A power plant characterized by being supplied to the plant.

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