JPS61128007A - Removing device for iron oxide in electric power plant feedwater system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention uses a magnet to remove iron oxides mixed into the water supply system of steam power engines in thermal power plants and other power plants. The present invention relates to an apparatus for removing iron oxides in a water supply system of a power plant, which is suitable for controlling the amount of water and implementing the above-mentioned water supply management.

[Background of the invention]

In general, most of the steam power equipment in power plants is made of steel, so iron oxides are likely to be mixed into the water supply.

Contaminated iron oxides can cause water pipes to burn out.

Conventionally, anti-corrosion chemicals were added to the water supply to suppress the generation of iron oxides, as this could lead to various malfunctions such as a reduction in motor output and damage to the water pump due to overload9. Efforts have been made to remove iron oxides from the water supply.

As an iron oxide removal device using the above magnetic force, there is an electromagnetic filter (Japanese Patent Application No. 47-49482) in which an electromagnetic wire ring is provided around the outer periphery of a container containing particles made of ferromagnetic material. However, the above-mentioned electromagnetic filter requires a large current to be passed through the electromagnetic coil to excite the particles in the container, so it consumes a lot of power, and it generates heat, so it has to be equipped with a cooling means. That's uneconomical. Additionally, a Kudo water dispenser using permanent magnets has been developed, but this type of water dispenser is not widely used because it is difficult to clean when it becomes clogged. In addition, sintered metal filters and resins have been developed to remove impurities from water, but these filters have problems such as increased flow resistance due to clogging, and resins decompose at high temperatures. Ta.

Figure 1 shows the water supply system of a thermal power plant.

Condensate from the turbine 1 is supplied to a condenser 2, a condensate hot fer 3, a condensate pipe 4, a condensate pump 5, a condensate desalination system gL6, a condensate boost pump 7, low pressure feed water heaters 8a, 8b, 8c, deaerator deaerator chamber 9 and deaerator water storage tank 10 of deaerator 90
, delivery piping 11, boiler feed water pump 12, and high pressure feed water heater 13a.

13b and 13C, enters the boiler 14, becomes steam, flows into the turbine 1 via the main steam pipe 15, performs work, and returns to the condenser 2. 16a.

16b, 16c are low pressure feed water heater drain pipes, 17a,
17b and 17c are high-pressure water supply fA machine tray 7 pipes, 18 is a drain pump, and 19a, 19b to 19f are extraction pipes from the turbine 1.

FIG. 2 shows the internal structure of the deaerator 90. The deaerator 90 is composed of a deaerator chamber 9 and a deaerator water storage tank 10.

The deaerator deaeration chamber 9 is installed above the deaerator water storage tank 10, and has a tray chamber 21 in the center, a spray valve 22 in the upper part, a heating steam port 23 and a high pressure feed water heater drain inlet 24 in the side.
are provided for each.

Further, a downcomer pipe 25 and a distribution pipe 27 are interposed and communicated between the deaerator deaeration chamber 9 and the deaerator water storage tank 10. 26 is a pressure equalizing pipe for equalizing pressure.

Feed water that flows into the deaerator deaeration chamber 9 from the spray valve 22 and is heated and deaerated with heated steam, and drain that flows into the deaerator deaeration chamber 9 from the high pressure feed water heater drain inlet 24. Water supply means that the entire amount flows down in the downpipe 25 and is transferred to the distribution pipe 27.
The water is divided into streams, enters the deaerator water storage tank 10, and flows out from the water supply outlet 28.

As mentioned above, iron oxide removal equipment mixed into the water supply system has been adopted in the prior art, but it has the above-mentioned problems and is difficult to control and maintain the removal equipment. There are also not enough shortcomings.

[Purpose of the invention]

The present invention was devised to solve the above-mentioned problems, and its purpose is to find the most effective location for removing iron oxides, to economically remove the iron oxides, and to
An object of the present invention is to provide an apparatus for removing iron oxides in a water supply system of a power generation plant, which manages water supply and maintains and manages the amount of attached iron oxides below a predetermined value.

[Summary of the invention]

In order to achieve the above object, the present invention researched the elution location of iron oxides in the circulating water system of the steam engine of a power plant, and determined that the interior of the deaerator was the location where iron oxides could be most effectively removed. At the same time, a magnetic adsorption means is provided for adsorbing iron oxides in the deaerator water storage tank of the deaerator, and
Water level detection means for detecting the water level difference between the upstream and downstream sides of the magnetic adsorption means in the deaerator water storage tank; iron oxidation means for detecting iron oxides in the feed water introduced into or sent out from the deaerator; An object detection means is provided, and an alarm generation means is provided to notify that the adsorption capacity of the magnetic adsorption means is at the limit Vc6 based on these detection signals, and the amount of attached iron oxide is maintained below a predetermined value. Further, the present invention is characterized by an iron oxide removal device in a water supply system of a power generation plant, in which the maintenance timing of the magnetic attraction means can be accurately determined.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings.

First, an outline of this embodiment will be explained.

The iron oxides in the water supply system of a thermal power plant are mainly ferromagnetic materials Fe3O4 and 7"-Fe203r. As will be described later, these iron oxides are most effectively removed by the deaerator 90. It turned out to be true.

As shown in FIG. 5, the deaerator water storage tank 10 of the deaerator 90
A plurality of magnetic adsorption means 30 are disposed inside to adsorb and remove iron oxides in the water supply. The water level in the deaerator water storage tank 10 differs depending on the position before and after the water supply contacts the magnetic attraction means, and in order to detect this water level, a next level detection means 400 is provided in engagement with the deaerator water storage tank 1G. ing. The water level detection means is formed by detectors 42, 43, level oscillators 40, 41, etc. connected thereto. Also, condensate piping 50,
The delivery piping 11 that sends feed water from the deaerator water storage tank 10 to the boiler feed water pump 12 and the high-pressure feed water heater drain piping 17c are provided with an iron oxide detection means serving as an iron oxide detection means for detecting the respective iron oxides. 60, 61, and 62 are engaged. Further, the level oscillator 4 of the water level detection means 400
0.41 and the detection signals from the ferric acid 1 arsenic detection means 60, 61.62 are sent to the arithmetic unit 100 of the alarm generation means 300.
is input. The alarm generating means 300 is composed of the arithmetic unit 100 and the alarm device 201. Condensate piping 50. There are valves 5 in each of the high pressure water heater drain pipes 17c and 17d.
5.56 is provided.

With the above configuration, iron oxides are removed in the deaerator water storage tank 10, and the amount of iron oxides collected by the magnetic attraction means 30 is detected by the detection means, and iron oxides in the water supply system are removed. In addition to managing the amount of magnetic attraction means 30, the maintenance timing of the magnetic attraction means 30 is accurately grasped and maintained, thereby achieving the above object.

This example will be explained in more detail below.

In order to elucidate the source of iron oxides in the water supply system, power generation waste input (power generation output 250 MW) and power station B (power generation output 350 MW) were conducted.
W), Power Plant C (350 MW), Power Plant D (4 s
OMW), and Power Plant E (5 of 100,100O)
A comprehensive water quality test was carried out at a thermal power plant and the results were published in the 3rd edition.
As shown in the figure.

Figure 3 shows the locations where water supply temples were collected on the horizontal axis).
The vertical axis shows the iron oxide content in terms of iron concentration. The X mark indicates the discharged waste, the 0 mark indicates the same B, the Δ mark indicates the same 010 mark indicates the same DXψ
The mark represents the measured value at E.

As can be understood from this figure, iron in the system water decreases at the outlet of the condensate desalination device 6, hardly increases at the inlet of the deaerator chamber 90, but increases at the outlet of the deaerator water storage tank 10. However, at the inlet of the boiler 14, it decreases again. Therefore,
When the iron content of the high-pressure feed water heater drain water entering the deaerator deaeration chamber 9 was analyzed, a large amount of iron content was detected in this drain water.

From the above investigation results, (a) the iron content in the feed water is removed by the condensate demineralizer 6, but (b) the drains of the high-pressure feed water heaters 13a, 13b, and 13c, which have a high iron content, are removed by the deaerator (deaerator). The iron concentration in the feed water increases because it flows into the deaerator chamber 9 and the deaerator water storage tank 10), and (c) some of the iron content is transferred to the high-pressure feed water heaters 13a, 13b, 13C
(b) The remainder flows into the boiler 14 and a part of it is deposited in the boiler water pipe, and (e) The iron that has passed through the boiler 14 flows into the turbine 1 with steam and is deposited inside the turbine 1. It is determined that the

Due to the behavior of iron in the system water as described above, the source of iron oxides is the high-pressure feed water heaters 13a and 13b.

It became clear that the drain piping system 17C, 17b, and 17a of 13C was corroded.

As explained above, iron oxides that precipitate and accumulate in various parts of the steam engine of a thermal power plant are contained in the drain of the high-pressure feed water heater and flow into the deaerator 90. It has become clear that removing iron oxides in 1990 is the most rational and effective method.

In addition, the entire amount of feed water treated in the deaerator degassing chamber 9 passes through the down pipe 25 and the distribution pipe 27 to the deaerator water storage tank 10.
The water flows down into the water tank 10, flows through the water storage tank 10, and reaches the water supply outlet 2.
8, this channel system is suitable for installing the magnetic attraction means 30, and in particular, inside the deaerator water storage tank 10, which has a large channel cross-sectional area, is most suitable.

As shown in FIG. 4, the distribution pipe 2 in the deaerator water storage tank 10
A plurality of magnetic attraction means 30 are provided at appropriate intervals at positions facing the center side from the outlet 7. The magnetic attraction means 30 is composed of a permanent magnet 32 and a column supporting the permanent magnet 32, and iron oxides in the water supply are collected on the surface of the permanent magnet 32.

The feed water flowing out from the distribution pipe 27 into the deaerator water storage tank 10 is sent out from the water supply outlet 28 after passing between the magnetic attraction means 30, but due to the flow resistance flowing between the magnetic attraction means 30, the water supply The liquid level of the supplied water differs before and after it contacts the magnetic attraction means 30. Detectors 42 and 43 for detecting the different liquid levels are provided as shown.

Next, as shown in FIG.
A level oscillator 40°41 input to 00 is connected.

Further, a condensate pipe 50 connects the low pressure feed water heater 8C and the deaerator 90, a delivery pipe 11 connects the outlet of the deaerator water storage tank 10 and the high pressure feed water heater 13a via the water pump 12, and The high-pressure feed water heater drain pipe 17C has an iron oxide detection means for detecting iron oxides in the feed water flowing through these pipes.
Valves 55 and 56 are respectively interposed in the high-pressure feed water heater drain pipe 17d that connects the high-pressure feed water heater 3a and the low-pressure feed water heater 8C. Further, the water level signal from the level oscillator 40.41 and the iron oxide detection signal from each iron oxide concentration sensor 60, 61.62 are input to the arithmetic unit 100 of the alarm generating means 300, and the water level difference Δh and the iron oxide concentration difference ΔFe are calculated, and a comparison calculation with a set value inputted in advance is performed. The percentage alarm generating means 300 is attached with an alarm device 201 that issues an alarm when the above-mentioned calculated value exceeds a set value.

Next, FIG. 6 shows the flow rate (m/3) of the feed water flowing between the magnetic attraction means 30 in the deaerator water storage tank 10 (shown on the horizontal axis) and the amount of iron oxide adsorbed by the magnetic attraction means 30. The relationship with the iron oxide shedding rate (chi) (shown on the vertical axis) is shown. When the flow velocity exceeds about 0.05 m/s, the iron oxide shedding rate starts to rise and increases along a quadratic curve. Permanent magnet 3
2, as the iron oxides are collected, the flow rate of the feed water flowing between them increases, the water level difference Δh increases, and when it exceeds the above 0.05 m/s, part of the collected iron oxides increases. This results in an increase in the amount of iron oxide in the feed water sent to the intermediate pressure feed water heater 13a side. Based on the above, the water level difference Δh, the concentration of iron ra oxide, and the concentration difference Δ
By detecting pe and comparing it with a predetermined value Δhay ΔFe, the condition of the water supply system can be managed, and the usage limit of the magnetic force absorption hand R30, that is, the maintenance period can be grasped.

Next, the operation of this embodiment will be explained.

In FIG. 7, the horizontal axis shows time, and the 11th minor axis shows the iron oxide concentration (expressed as 4 degrees Fe) and the deaerator water storage tank level.

As time passes, the water level difference Δh gradually increases, and
Degassing! 1) The p4 degree difference Δpe between the 900 Å inlet and the outlet also increases, and these exceed the set value ΔhglΔF e s
/, Δp e /, an alarm is issued.

As described above, the magnetic attraction means 30 effectively adsorbs and removes iron oxides, and also easily limits its use.
By grasping this accurately and maintaining the magnetic attraction means 30, it is possible to continue the attraction and removal process again. In addition, the magnetic attraction means 30 removes iron oxide using the permanent magnet 32, and does not consume a large amount of power like the electromagnetic filter in the prior art, so the operating cost is low and there is no risk of generating heat. It is economical and requires no additional cooling means.

In addition, there is no risk of clogging as in conventional p-watertight iron oxide removal devices, and the iron oxides adhering to the surface of the permanent magnet 32 can be easily wiped off and cleaned, resulting in a hassle-free handling process. Maintenance and management are easy as no maintenance is required.

Furthermore, unlike conventional iron oxide removal devices using resin, there is no problem with heat resistance, and the device is excellent in durability.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, it is possible to economically remove iron oxides in water supply, and to maintain and manage the amount of iron oxides adhering to a predetermined value or less through water supply management. It can be raised.

[Brief explanation of the drawing]

Figure 1 is a water supply system diagram of a thermal power plant, Figure 2 is a sectional view of a deaerator in the system, Figure 3 is a line diagram showing the results of water quality tests in the system, and Figure 4 is an embodiment of the present invention. FIG. 5 is a sectional view showing the magnetic attraction means, and FIG. 5 is a system diagram explaining the configuration of this embodiment.
FIG. 6 is a diagram showing the relationship between the flow rate of water supply and the iron oxide shedding rate, and FIG. 7 is a diagram showing the operational characteristics of this embodiment. 1... Turbine, 2... Condenser, 8a, 8b, Qc
...Low pressure feed water heater, 9...Deaerator deaeration chamber, 10.
... Deaerator water storage tank, 11... Delivery piping, 13a,
13b. 13C...High pressure water heater, 14...Boiler, 17
a. 17b, 17c, 17d...High pressure water heater drain pipe, 27...Distribution pipe, 28...Water supply outlet, 30...
・Magnetic attraction means, 31... Strut, 32... Permanent magnet, 40° 41... Level oscillator, 42.43... Detector, 50... Condensate piping, 55, 56... valve, 60
, 61.62... Iron oxide detection sensor, 90... Deaerator, 100... Arithmetic device, 201... Alarm, 3
00...Alarm generation means, 400...Water level detection means.

Claims (1)

[Claims] 1. Deaerate the feed water sent from the upstream condenser via the low-pressure feed water heater and the feed water drained from the downstream high-pressure feed water heater, and transfer the degassed feed water to the deaerator water storage tank. In a power plant water supply system having a deaerator which supplies water to the high-pressure feed water heater while storing it in the water supply tank, a magnetic adsorption means for adsorbing iron oxides mixed in the feed water is provided in the deaerator water storage tank. In addition, the deaerator is provided with water level detection means for detecting a water level difference between the upstream side and the downstream side of the magnetic adsorption means in the deaerator water storage tank, and water supply introduced into the deaerator and the deaerator. Based on an iron oxide detection means for detecting the iron oxide in the water supply sent downstream from the water container, a water level difference signal from the water level detection means, and an iron oxide concentration difference signal from the iron oxide detection means, An apparatus for removing iron oxides in a water supply system of a power plant, characterized in that an alarm generating means for generating an alarm is provided.