Requirements on Feed Water, Boiler Water and Steam for Steam Generators

1992 ◽  
pp. 147-153
Author(s):  
◽  
Keyword(s):  
Feed Water ◽  
Steam Generators ◽  
Boiler Water

scholarly journals Treatment Method Assessment of the Impact on the Corrosivity and Aggressiveness for the Boiler Feed Water

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1965 ◽  
Author(s):  
Skoczko ◽  
Szatyłowicz
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Saturation Index ◽  
Treatment Plant ◽  
High Water ◽  
Feed Water ◽  
Exchange Cation ◽  
Boiler Water ◽  
The Impact ◽  
Boiler Feed Water

The aim of the study was the assessment of corrosivity and aggressiveness for boiler feed water. The negative effects of water corrosivity and aggressiveness may include silting up of the steel water supply system and the destruction of boiler equipment touched or washed by such water. They may cause the whole industrial production system to fail or be destroyed. That is why it was important to reach a high water purification level, including the calculation of water aggressiveness and corrosivity indicators. The carried out test showed that the simple system used before the modernization of the industrial water treatment plant is not sufficient to reach clean and stable water. The authors proposed modernization, including additional processes to improve boiler water quality, and designed new devices for water treatment. As a result of the new idea, groundwater taken as raw water was treated in individual and complex processes, such as pre-aeration, filtration, ion exchange (cation and anion exchange resigns), extra aeration, and extra degassing. The conducted research included chemical analyses of raw and treated water. In the conducted studies, the indirect method of water aggressiveness and corrosivity assessment was applied using mathematical calculation of the Langelier Saturation Index (LSI), the Ryznar Stability Index (RI), the Larson–Skold Index (LI), and the Singley Index (SI). The results proved that the new proposed processes for the boiler feed water treatment station allow reaching a high water quality and low level of water aggressiveness and corrosion.

The Care of Modern Steam-Generating Plant from the Water Side

1935 ◽  
Vol 129 (1) ◽  
pp. 7-70 ◽  
Author(s):  
R. J. Glinn
Keyword(s):  
High Pressures ◽  
Feed Water ◽  
Working Pressure ◽  
Correct Treatment ◽  
Boiler Water ◽  
Satisfactory Condition ◽  
Water Side ◽  
Rate Of Evaporation ◽  
Additional Reference ◽  
And Control

The condition of the metal of the boiler units of the modern steam-generating plant is affected by the condition of the water which is used as feed. Compared with typical figures of a few years ago, the working pressure and the degree of superheat of the steam have increased, in addition to the rate of evaporation resulting from improved methods of firing and combustion. These factors influence the effect of the water on the metal parts. An examination is made of various feed water circuits and of the methods of treating and controlling the quality of the feed and boiler water. Various examples are given of the difficulties which can occur, due to incorrect treatment and control, both in respect of scale and corrosion troubles. The causes of such troubles and the means for overcoming them are also considered. Instances of failures of economizer, boiler, and superheater tubes are given, and additional reference is made to the causes and effect of caustic embrittlement of the metal of the boiler. By careful attention to definite rules for the correct treatment and control of feed and boiler water conditions, steam-generating plants will keep in satisfactory condition under the exacting influence of the high pressures, high superheats, and high ratings of the present day.

Effect of Boiler Feedwater Inlet Locations on the Water Circulation Characteristics in a Firetube Boiler With the Non-Symmetrically Arranged Tube Passes 3 and 4

2002 ◽  
Author(s):  
Hyunjae Park ◽  
Anthony Bowman ◽  
Tod Stansfield ◽  
Brian Huibregtse ◽  
Steve Wilkinson ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Pressure Vessel ◽  
Water Circulation ◽  
Feed Water ◽  
Boiler Furnace ◽  
Boiler Water ◽  
Furnace Section ◽  
Circulation Patterns ◽  
Boiler Feedwater ◽  
Circulation Characteristics

Since the furnace section of a boiler is the primary heat transfer surface for the production of vapor, the overall water circulation patterns in the boiler will be significantly influenced by the circulation patterns near the furnace area. Boiler water circulation characteristics for a newly designed 4-pass firetube boiler with the non-symmetric arrangement of tube passes 3 and 4 were investigated in the previous work [1], in which the attraction forces between 28 different temperature nodes on the furnace wall were evaluated to predict the characteristics of water circulation near the boiler furnace. It was found that various non-symmetric water circulation patterns would occur for different firing conditions. As a consequence, in this paper, the analysis methods developed in the authors’ previous work are explicitly employed to predict and improve the water circulation in a firetube boiler when 6 different boiler feedwater inlet locations (3 on the right-hand side and 3 on the left-hand side of the boiler vessel shell) are used. Each side has 3 different feedwater inlet locations below the centerline of the boiler pressure vessel along its length. Investigation of the analysis results reveals that non-symmetric water circulation patterns are not unavoidable, but improvements in the water circulation and potentially the heat transfer rate can be achieved when the boiler feed water inlet is located near the front head of the boiler pressure vessel.

Steam Generator In-Service Inspections at Paks NPP

2008 ◽  
Author(s):  
Miklo´s Do´czi
Keyword(s):  
Heat Exchanger ◽  
Steam Generator ◽  
Eddy Current ◽  
Power Plants ◽  
Tube Bundle ◽  
Degradation Mechanism ◽  
Feed Water ◽  
Material Damage ◽  
Steam Generators ◽  
Service Inspection

Steam Generator is one of the most critical components in nuclear power plants. It has of overriding importance from point of view of safe and reliable operation of the whole plant. Variety of degradation mechanisms affecting SG tube bundle may cause different types of material damage. In Paks NPP eddy current in-service inspection have been performed since 1988. In the year 1997 higher number of defected tubes were found in case of Unit#2, compared to results of the previous years. A medium term SG inspection program had been performed in the time period between 1998–2004. Based on the results of eddy current inspections high number of heat exchanger tubes had been plugged. Chemical cleanings of all steam generators were performed aiming to reduce the magnetite, copper deposits and corrosion agents acting on the surface of the tubes. Replacement of the main condensers had been performed to stop the uncontrolled water income caused by the relatively frequent leakages of the condenser tubes. Several tube samples had been cut from the first row of the tube bundles of different steam generators to study the effectiveness of the cleaning process and to determine the composition of deposits on the tube outside surface. Also several tubes with eddy current indications had been pulled out from the steam generators to determine the acting degradation mechanism. Examination of removed tubes can provide opportunity to check the reliability of eddy current inspection using bobbin coil. Also there were tubes pulled out form SG with existing cracks. From the year 2005 new inspection program had been started. As the first results of the new inspection program shows, there is only a few new indications had been found and there is no measurable crack propagation in case of existing indications. During the recent years feed-water collectors were replaced in case of all units of the power plant, because of material damage (erosion corrosion). The paper summarizes the results of eddy current in-service inspection of heat exchanger tubes, results of examinations of removed tubes and also deals with results of visual examination of the feed-water distributor system.

Diagnosis for Water and Steam Quality Problem in Taishan Ultra-Supercritical Power Plant

2014 ◽  
Vol 1044-1045 ◽  
pp. 291-294
Author(s):  
Mao Dong Li ◽  
Chen Lin Dai ◽  
Jun Ming Zhao ◽  
Yu Hui Du ◽  
Lin Yang ◽  
...  
Keyword(s):  
Water Treatment ◽  
Power Plant ◽  
Dissolved Oxygen ◽  
Working Condition ◽  
Iron Deposit ◽  
Feed Water ◽  
Steam Quality ◽  
Control Effect ◽  
Boiler Water ◽  
Quality Problem

Water and steam quality during operation must be strictly controlled for ultra-supercritical unit. Changes of indicators in water and steam are supervised, water and steam quality and working condition of boiler water, as well as supervision of water and steam quality are reviewed in this paper. Risks of corrosion and scaling in Taishan power plant is assessed. As a result, control effect of TOC is remarkable in Taishan power plant, content of Cl- and SO42- can satisfy the control standard, that is , risk of corrosion and scaling is low. Dissolved oxygen is significantly exceeded in the condensate polishing desalination device , and there has risk of iron deposit. To convert the feed water treatment from AVT(All Volatile Treatment) to OT(Oxygenated Treatment) can solve the problems above .

scholarly journals Fouling Of Nuclear Steam Generators: Fundamental Studies, Operating Experience and Remedial Measures Using Chemical Additives

2013 ◽  
Vol 2 (1) ◽  
pp. 61-88 ◽  
Author(s):  
C.W. Turner
Keyword(s):  
Economic Performance ◽  
Nuclear Power ◽  
Power Plants ◽  
Tube Bundle ◽  
Operating Experience ◽  
Feed Water ◽  
Chemical Additives ◽  
Steam Generators ◽  
Primary Coolant ◽  
And Performance

Fouling remains a potentially serious issue that if left unchecked can lead to degradation of the safety and performance of nuclear steam generators (SGs). It has been demonstrated that the majority of the corrosion product transported with the feed water to the SGs accumulates in the SG on the tube-bundle. By increasing the risk of tube failure and acting as a barrier to heat transfer, deposit on the tube bundle has the potential to impair the ability of the SG to perform its two safety-critical roles: provision of a barrier to the release of radioactivity from the reactor coolant and removal of heat from the primary coolant during power operation and under certain post accident scenarios. Thus, it is imperative to develop improved ways to mitigate SG fouling for the long-term safe, reliable and economic performance of nuclear power plants (NPPs). This paper provides an overview of our current understanding of the mechanisms by which deposit accumulates on the secondary side of the SG, how this accumulation affects SG performance and how accumulation of deposit can be mitigated using chemical additives to the secondary heat-transport system. The paper concludes with some key questions that remain to be addressed to further advance our knowledge of deposit accumulation and how it can be controlled to maintain safe, economic performance of nuclear SGs.

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