Ultrasonic Creep Damage Detection by Frequency Analysis for Boiler Piping

2006 ◽  
Vol 129 (4) ◽  
pp. 713-718 ◽  
Author(s):  
Hiroaki Hatanaka ◽  
Nobukazu Ido ◽  
Takuya Ito ◽  
Ryota Uemichi ◽  
Minoru Tagami ◽  
...  
Keyword(s):  
Power Generation ◽  
High Temperature ◽  
Damage Detection ◽  
Fossil Fuel ◽  
Creep Damage ◽  
High Energy ◽  
Assessment Method ◽  
Nondestructive Method ◽  
Fuel Combustion ◽  
Fossil Fuel Combustion

Boiler piping of fossil-fuel combustion power generation plants are exposed to high-temperature and high-pressure environments, and failure of high-energy piping due to creep damage has been a concern. Therefore, a precise creep damage assessment method is needed. This paper proposes a nondestructive method for creep damage detection of piping in fossil-fuel combustion power generation plants by ultrasonic testing. Ultrasonic signals are transformed to signals in a frequency domain by Fourier transform, and a specific frequency band is chosen. To determine the creep damage, the spectrum intensities are calculated. Calculated intensities have a good correlation to life consumption of the weld joints, and this method is able to predict the remaining life of high-temperature piping, which has been already installed.

Making deep reductions in CO2 emissions from coal-fired power plant using capture and storage of CO2

2003 ◽  
Vol 217 (1) ◽  
pp. 1-7 ◽  
Author(s):  
P Freund
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Fossil Fuel ◽  
Fuel Combustion ◽  
Fossil Fuel Combustion ◽  
Energy Technologies ◽  
Potential Capacity ◽  
Barriers To Implementation ◽  
Reduce Emissions ◽  
And Storage

Concerns about potentially dangerous changes in climate as a result of rising levels of greenhouse gases in the atmosphere are leading to restrictions on emissions of carbon dioxide (CO2), the principal anthropogenic greenhouse gas. The main source of CO2 emissions is fossil fuel combustion; power generation is the single largest contributor. Coal is widely used for power generation, but it releases approximately twice as much CO2 compared with the use of natural gas for each unit of electricity sent out. Emission reduction could be achieved by increasing the efficiency with which coal is burnt, or by switching to another fuel. These measures can achieve significant reductions in emissions, but, for deep reductions, more substantial changes would be required in the power plant. The technology for capture and storage of CO2 has been recognized in recent years as providing a means of cutting emissions from fossil fuel combustion by at least 80 per cent. Capture and storage is based on technology already in use for other purposes, so there is limited need for development, and the risk of application will be less than is typical for novel energy technologies. Hence, this seems to be a technology that could be deployed relatively rapidly to reduce emissions from fossil fuel fired plant. In this paper, the technology for capture and storage of CO2 will be reviewed, especially the costs and potential capacity for reducing emissions. Some barriers to implementation are identified, and work necessary to overcome them is discussed.

Response : Sulfur Mobilization as a Result of Fossil Fuel Combustion

Science ◽  
1972 ◽  
Vol 175 (4027) ◽  
pp. 1279-1279
Author(s):  
K. K. Bertine ◽  
Edward D. Goldberg
Keyword(s):  
Fossil Fuel ◽  
Fuel Combustion ◽  
Fossil Fuel Combustion

scholarly journals Seasonal changes in Fe species and soluble Fe concentration in the atmosphere in the Northwest Pacific region based on the analysis of aerosols collected in Tsukuba, Japan

2013 ◽  
Vol 13 (15) ◽  
pp. 7695-7710 ◽  
Author(s):  
Y. Takahashi ◽  
T. Furukawa ◽  
Y. Kanai ◽  
M. Uematsu ◽  
G. Zheng ◽  
...  
Keyword(s):  
Fossil Fuel ◽  
Fuel Combustion ◽  
Anthropogenic Sources ◽  
Anthropogenic Activity ◽  
Northwest Pacific ◽  
Pacific Region ◽  
Fossil Fuel Combustion ◽  
Factors Affecting ◽  
X Ray ◽  
Fe Species

Abstract. Atmospheric iron (Fe) can be a significant source of nutrition for phytoplankton inhabiting remote oceans, which in turn has a large influence on the Earth's climate. The bioavailability of Fe in aerosols depends mainly on the fraction of soluble Fe (= [FeSol]/[FeTotal], where [FeSol] and [FeTotal] are the atmospheric concentrations of soluble and total Fe, respectively). However, the numerous factors affecting the soluble Fe fraction have not been fully understood. In this study, the Fe species, chemical composition, and soluble Fe concentrations in aerosols collected in Tsukuba, Japan were investigated over a year (nine samples from December 2002 to October 2003) to identify the factors affecting the amount of soluble Fe supplied into the ocean. The soluble Fe concentration in aerosols is correlated with those of sulfate and oxalate originated from anthropogenic sources, suggesting that soluble Fe is mainly derived from anthropogenic sources. Moreover, the soluble Fe concentration is also correlated with the enrichment factors of vanadium and nickel emitted by fossil fuel combustion. These results suggest that the degree of Fe dissolution is influenced by the magnitude of anthropogenic activity, such as fossil fuel combustion. X-ray absorption fine structure (XAFS) spectroscopy was performed in order to identify the Fe species in aerosols. Fitting of XAFS spectra coupled with micro X-ray fluorescence analysis (μ-XRF) showed the main Fe species in aerosols in Tsukuba to be illite, ferrihydrite, hornblende, and Fe(III) sulfate. Moreover, the soluble Fe fraction in each sample measured by leaching experiments is closely correlated with the Fe(III) sulfate fraction determined by the XAFS spectrum fitting, suggesting that Fe(III) sulfate is the main soluble Fe in the ocean. Another possible factor that can control the amount of soluble Fe supplied into the ocean is the total Fe(III) concentration in the atmosphere, which was high in spring due to the high mineral dust concentrations during spring in East Asia. However, this factor does not contribute to the amount of soluble Fe to a larger degree than the effect of Fe speciation, or more strictly speaking the presence of Fe(III) sulfate. Therefore, based on these results, the most significant factor influencing the amount of soluble Fe in the North Pacific region is the concentration of anthropogenic Fe species such as Fe(III) sulfate that can be emitted from megacities in Eastern Asia.

scholarly journals Sources and formation of carbonaceous aerosols in Xi'an, China: primary emissions and secondary formation constrained by radiocarbon

2020 ◽  
Author(s):  
Haiyan Ni ◽  
Ru-Jin Huang ◽  
Ulrike Dusek
Keyword(s):  
Biomass Burning ◽  
Coal Combustion ◽  
Vehicle Emissions ◽  
Fossil Fuel ◽  
Fuel Combustion ◽  
Warm Period ◽  
Water Soluble ◽  
Formation Mechanisms ◽  
Carbonaceous Aerosols ◽  
Fossil Fuel Combustion

<p>To investigate the sources and formation mechanisms of carbonaceous aerosols, a major contributor to severe particulate air pollution, radiocarbon (<span><sup>14</sup>C</span>) measurements were conducted on aerosols sampled from November 2015 to November 2016 in Xi'an, China. Based on the <span><sup>14</sup>C</span> content in elemental carbon (EC), organic carbon (OC) and water-insoluble OC (WIOC), contributions of major sources to carbonaceous aerosols are estimated over a whole seasonal cycle: primary and secondary fossil sources, primary biomass burning, and other non-fossil carbon formed mainly from secondary processes. Primary fossil sources of EC were further sub-divided into coal and liquid fossil fuel combustion by complementing <span><sup>14</sup>C</span> data with stable carbon isotopic signatures.</p><p>The dominant EC source was liquid fossil fuel combustion (i.e., vehicle emissions), accounting for 64 % (median; 45 %–74 %, interquartile range) of EC in autumn, 60 % (41 %–72 %) in summer, 53 % (33 %–69 %) in spring and 46 % (29 %–59 %) in winter. An increased contribution from biomass burning to EC was observed in winter (<span>∼28</span> %) compared to other seasons (warm period; <span>∼15</span> %). In winter, coal combustion (<span>∼25</span> %) and biomass burning equally contributed to EC, whereas in the warm period, coal combustion accounted for a larger fraction of EC than biomass burning. The relative contribution of fossil sources to OC was consistently lower than that to EC, with an annual average of <span>47±4</span> %. Non-fossil OC of secondary origin was an important contributor to total OC (<span>35±4</span> %) and accounted for more than half of non-fossil OC (<span>67±6</span> %) throughout the year. Secondary fossil OC (SOC<span><sub>fossil</sub></span>) concentrations were higher than primary fossil OC (POC<span><sub>fossil</sub></span>) concentrations in winter but lower than POC<span><sub>fossil</sub></span> in the warm period.</p><p>Fossil WIOC and water-soluble OC (WSOC) have been widely used as proxies for POC<span><sub>fossil</sub></span> and SOC<span><sub>fossil</sub></span>, respectively. This assumption was evaluated by (1) comparing their mass concentrations with POC<span><sub>fossil</sub></span> and SOC<span><sub>fossil</sub></span> and (2) comparing ratios of fossil WIOC to fossil EC to typical primary OC-to-EC ratios from fossil sources including both coal combustion and vehicle emissions. The results suggest that fossil WIOC and fossil WSOC are probably a better approximation for primary and secondary fossil OC, respectively, than POC<span><sub>fossil</sub></span> and SOC<span><sub>fossil</sub></span> estimated using the EC tracer method.</p>

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