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Enhancing Smart Grid Resiliency
Published in Clark W. Gellings, Smart Grid Planning and Implementation, 2020
Fossil plants experience most of the damage from HILF events due to flooding and interruptions in fuel supplies, steep ramp rates, fast starts and shutdowns, and extended periods of shutdown. This is simply based on cycling from cold to hot metal in a short time period. The mechanisms of damage they experience are:High-temperature, high-cycle creep fatigue.Vibrations—increases in valve body and small-bore pipe cracking.Stress corrosion cracking (SCC) due to steam quality changes and chemistry (turbine balding).Flow-accelerated corrosion due to changes in mass flow rates.Wear and tear on pumps and motors due to non-optimal operating points and changing loads.
A new technique for in-plant high mass transfer rate ECP monitoring
Published in Stefan Ritter, Anders Molander, Corrosion monitoring in nuclear systems: research and applications, 2017
The advantages of the new technique are summarised as follows: The sensor can be installed without penetration of the pressure boundaries of the system. Existing sampling lines can be used.The sensor comprises well-known parts that have been used for in-plant measurements in several reactors over many years.Local water chemistry and corrosion conditions can be accurately monitored and measurements can also be applied to flow-accelerated corrosion related studies.
Advanced Fossil Fuel Power Systems
Published in D. Yogi Goswami, Frank Kreith, Energy Conversion, 2017
In all-volatile treatment (AVT), boiler feedwater quality is controlled by adding non-solid chemicals such as ammonia (to control pH to prevent corrosion) and hydrazine (to scavenge oxygen). When the latter is used, the process is referred to as AVT-R. Oxygenated treatment (OT) or AVT-O with no hydrazine addition is based on the theory that slightly soluble oxides, such as Fe3+ oxide, forming on the boiler tube surface act as a protector against flow accelerated corrosion (FAC). There are two types of OT, neutral water treatment (NWT), in which dissolved oxygen is allowed to coexist in neutral water, and combined water treatment (CWT), in which dissolved oxygen is allowed to coexist in weak alkaline water adjusted to a pH range of 8.0–9.3 by ammonia.
Probabilistic analysis of electromagnetic acoustic resonance signals for the detection of pipe wall thinning
Published in Nondestructive Testing and Evaluation, 2021
Noritaka Yusa, Haicheng Song, Daiki Iwata, Tetsuya Uchimoto, Toshiyuki Takagi, Makoto Moroi
Pipe wall thinning caused by flow-accelerated corrosion (FAC) is a major form of degradation in various industries. Pipe wall thinning can lead to a serious accident, especially if it appears in a pipe carrying high pressure or hazardous fluids like those used in power or chemical plants [1], and thus many studies have been performed to quantitatively reveal the factors affecting wall-thinning rate. However, it is still challenging to predict the remaining service life of a pipe subjected to FAC accurately. Consequently, performing periodic non-destructive inspections is indispensable when evaluating pipe wall thickness so that proper maintenance actions can be taken to prevent accidents.