The Effect of Inspection on Maintenance Planning for Fossil Fuel Fired Power Plant

2014 ◽  
Author(s):  
Jun Takahashi ◽  
Shinsuke Sakai
Keyword(s):  
Standard Deviation ◽  
Sample Size ◽  
Power Plants ◽  
Fossil Fuel ◽  
Probability Of Failure ◽  
Stable Operation ◽  
Maintenance Planning ◽  
Boiler Tubes ◽  
The One ◽  
Inspection Data

Periodical inspection is necessary for stable operation of the plant. But usually, inspection cost and inspection period are limited, and it is difficult to inspect all of the objective location of the plant in allowed cost and period. Therefore, for maintenance planning, probability of failure is presumes by the obtained sample size inspection data. In that case, presumed probability of failure includes uncertainty, and the one-side tolerance limit of the probability is changed by the sample size of the inspection. For maintenance on boiler tubes of fossil fuel fired power plants, only limited sample size inspection data can be used for maintenance planning. On the other hand, the conditions of the tubes for maintenance are different because environmental conditions of the tubes like actual temperature are different. Then the inspection results don’t demand enough information to presume probability of failure because the standard deviation is not known. But usually to presume probability of failure for maintenance, the standard deviation is not considered only the average is used. Therefore, considering mainly uncertainties depend on sample size of the inspection data, presumed probability of failure is related to rational maintenance planning.

scholarly journals THE THEORY OF THE INTERNALLY STUDENTIZED RANGE DISTRIBUTION REVISITED

2018 ◽  
Vol 36 (4) ◽  
pp. 802
Author(s):  
Daniel Furtado FERREIRA ◽  
Lucas Monteiro CHAVES ◽  
Devanil Jaques de SOUZA
Keyword(s):  
Quality Control ◽  
Standard Deviation ◽  
Sample Size ◽  
Sample Standard Deviation ◽  
Normal Case ◽  
Detailed Proof ◽  
Range Distribution ◽  
Studentized Range ◽  
Uniform Case ◽  
The One

The present paper intends to revisit the distribution of the ratio of the range to the sample standard deviation, known as the distribution of the internally studentized range, in the normal case. This distribution has its importance recognized in several areas, as quality control and inference, for testing the lack of homogeneity of the data or kurtosis. An alternative distribution to the one presented by David et al. (1954), based on the distribution of the maximum, is proposed. We exhibit a detailed proof for the distribution of the internally studentized range in the normal case and sample size 3. We also provide a new result: the distribution for the uniform case with sample of size 3.

An Approach for Analysing Boiler Tubes Ultrasonic Inspection Data to Support Decision Making

2005 ◽  
Author(s):  
Soudabeh A. Noori ◽  
John W. H. Price
Keyword(s):  
Ultrasonic Inspection ◽  
Point Of View ◽  
Economic Life ◽  
Maintenance Planning ◽  
Power Station ◽  
Practical Point ◽  
Boiler Tubes ◽  
Critical Components ◽  
Inspection Data ◽  
Support Decision Making

There is now much interest in the development of risk based strategies for maintenance planning including assessing appropriate inspection strategies and making economic life estimates of critical components. This study examines this problem from a practical point of view by studying a significant body of tube thickness inspection data collected in a power station. This data naturally has all sorts of difficulties. For example there are issues related to the accuracy and correctness of the measurements. Then there is the issue of how to use the data to determine deterioration rates and life expectancy. This paper examines this data using: • a method developed by the authors: a procedure based on a “warning level” approach, and • a suggested interpretation of the American Petroleum Institute’s technique of “risk based inspection”.

Performance Evaluation of Occupant Classification Systems

2004 ◽  
Author(s):  
Glen Lichtenberg ◽  
Kirsten Carr
Keyword(s):  
Standard Deviation ◽  
Sample Size ◽  
Continuous Variable ◽  
Classification Performance ◽  
Classification Systems ◽  
Test Case ◽  
Tolerance Interval ◽  
Noise Sources ◽  
Interval Method ◽  
The One

The new FMVSS 208 Federal Regulation requires restraint systems to focus on occupants other than the 50th percentile male. The new focus includes small adults and children. As a result, restraint systems may need to perform differently for several occupant classes, thereby creating a need for occupant classification systems (OCS). A typical regulation compliance strategy is to suppress the restraint system when a child occupies the front passenger seat and to enable the restraints when an adult occupies the seat. The regulation provides specific weight and height ranges to define these classes of seat occupants. The evolution of OCS technologies produced a need for test methodologies and objective metrics to measure classification system capability. The application of the statistical one-sided tolerance interval to OCS systems has proven invaluable in measuring classification performance and driving system improvements. The one-sided tolerance method is based on a single continuous variable, such as weight. A single common threshold, or tolerance limit, is used to compare two competing populations, such as 6-year-old versus 5th percentile female populations. Output of the method produces graphics demonstrating reliability as a function of potential threshold that objectively characterizes a system’s classification performance level. This paper also discusses the importance of applying the one-sided tolerance interval method to performance data that captures the noise sources that impact system performance. For occupant classification systems, noise sources include differences in test subjects’ sizes, how they sit in the seat, and how the seat is set-up. This paper also discusses the importance of sample size selection. Two methods of determining a sample size are presented. The first method uses the one-sided tolerance interval method equation directly. The second method simulates a noise source and selects a sample size where the noise standard deviation converges to its population variance. Once the mean, standard deviation, and sample size for each test case is known, the proposed method computes the reliability of each test case evaluated for a range of potential thresholds. A review of the resulting reliability curves characterizes classification performance. If an acceptable range of thresholds exists, the resulting range is referred to as a “threshold window.” System improvements can be directed toward those test cases that constrain the “threshold window.” This paper proposes a statistical method that can provide a solid measure of the robust capability of an OCS that classifies based on a single continuous variable (such as weight) to distinguish between occupant classes. This statistical method enables the careful balance necessary in setting thresholds.

Alkohol im Tank – Bio-Kraftstoffe und die Grenzen moderner Mobilität

2004 ◽  
Vol 34 (136) ◽  
pp. 455-468
Author(s):  
Hartwig Berger
Keyword(s):  
Third World ◽  
Fossil Fuel ◽  
Energy Resources ◽  
The Third ◽  
Political Conflicts ◽  
The Future ◽  
Long Time ◽  
Food Market ◽  
The One ◽  
The Third World

The article discusses the future of mobility in the light of energy resources. Fossil fuel will not be available for a long time - not to mention its growing environmental and political conflicts. In analysing the potential of biofuel it is argued that the high demands of modern mobility can hardly be fulfilled in the future. Furthermore, the change into using biofuel will probably lead to increasing conflicts between the fuel market and the food market, as well as to conflicts with regional agricultural networks in the third world. Petrol imperialism might be replaced by bio imperialism. Therefore, mobility on a solar base pursues a double strategy of raising efficiency on the one hand and strongly reducing mobility itself on the other.

Capturing CO2 in flue gas from fossil fuel-fired power plants using dry regenerable alkali metal-based sorbent

2013 ◽  
Vol 39 (6) ◽  
pp. 515-534 ◽  
Author(s):  
Chuanwen Zhao ◽  
Xiaoping Chen ◽  
Edward J. Anthony ◽  
Xi Jiang ◽  
Lunbo Duan ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Flue Gas ◽  
Power Plants ◽  
Fossil Fuel

scholarly journals Sustainable Energy-Related Infrastructure Development in the Mekong Subregion: Key Drivers and Policy Implications

2021 ◽  
Vol 13 (10) ◽  
pp. 5720
Author(s):  
Han Phoumin ◽  
Sopheak Meas ◽  
Hatda Pich An
Keyword(s):  
Carbon Dioxide Emissions ◽  
Energy Demand ◽  
Power Plants ◽  
Policy Implications ◽  
Infrastructure Investment ◽  
Infrastructure Development ◽  
Low Carbon ◽  
Energy Access ◽  
Low Carbon Economy ◽  
The One

Many players have supported infrastructure development in the Mekong Subregion, bridging the missing links in Southeast Asia. While the influx of energy-related infrastructure development investments to the region has improved the livelihoods of millions of people on the one hand, it has brought about a myriad of challenges to the wider region in guiding investments for quality infrastructure and for promoting a low-carbon economy, and energy access and affordability, on the other hand. Besides reviewing key regional initiatives for infrastructure investment and development, this paper examines energy demand and supply, and forecasts energy consumption in the subregion during 2017–2050 using energy modeling scenario analysis. The study found that to satisfy growing energy demand in the subregion, huge power generation infrastructure investment, estimated at around USD 190 billion–220 billion, is necessary between 2017 and 2050 and that such an investment will need to be guided by appropriate policy. We argue that without redesigning energy policy towards high-quality energy infrastructure, it is very likely that the increasing use of coal upon which the region greatly depends will lead to the widespread construction of coal-fired power plants, which could result in increased greenhouse gas and carbon dioxide emissions.

Boiler Implosion Control in Fossil Fuel Power Plants

1985 ◽  
Vol 107 (4) ◽  
pp. 267-269 ◽  
Author(s):  
S. Z. Wu ◽  
D. N. Wormley ◽  
D. Rowell ◽  
P. Griffith
Keyword(s):  
Power Plants ◽  
Fossil Fuel ◽  
Companion Paper ◽  
Simulation Techniques ◽  
Power Plant Boiler ◽  
Induced Draft Fan ◽  
Fossil Fuel Power Plants ◽  
Computer Simulation Techniques ◽  
Plant Boiler ◽  
Furnace Pressure

An evaluation of systems for control of fossil fuel power plant boiler and stack implosions has been performed using computer simulation techniques described in a companion paper. The simulations have shown that forced and induced draft fan control systems and induced draft fan bypass systems reduce the furnace pressure excursions significantly following a main fuel trip. The limitations of these systems are associated with actuator range and response time and stack pressure excursions during control actions. Preliminary study suggests that an alternative control solution may be achieved by discharging steam into the furnace after a fuel trip.

A Review of Crack Detection In-Line Inspection Case Studies

2010 ◽  
Author(s):  
Neil Bates ◽  
David Lee ◽  
Clifford Maier
Keyword(s):  
Crack Growth ◽  
Case Studies ◽  
Crack Detection ◽  
Growth Parameters ◽  
Probability Distributions ◽  
Low Frequency ◽  
Probability Of Failure ◽  
Probability Of Detection ◽  
Inspection Data

This paper describes case studies involving crack detection in-line inspections and fitness for service assessments that were performed based on the inspection data. The assessments were used to evaluate the immediate integrity of the pipeline based on the reported features and the long-term integrity of the pipeline based on excavation data and probabilistic SCC and fatigue crack growth simulations. Two different case studies are analyzed, which illustrate how the data from an ultrasonic crack tool inspection was used to assess threats such as low frequency electrical resistance weld seam defects and stress corrosion cracking. Specific issues, such as probability of detection/identification and the length/depth accuracy of the tool, were evaluated to determine the suitability of the tool to accurately classify and size different types of defects. The long term assessment is based on the Monte Carlo method [1], where the material properties, pipeline details, crack growth parameters, and feature dimensions are randomly selected from certain specified probability distributions to determine the probability of failure versus time for the pipeline segment. The distributions of unreported crack-related features from the excavation program are used to distribute unreported features along the pipeline. Simulated crack growth by fatigue, SCC, or a combination of the two is performed until failure by either leak or rupture is predicted. The probability of failure calculation is performed through a number of crack growth simulations for each of the reported and unreported features and tallying their respective remaining lives. The results of the probabilistic analysis were used to determine the most effective and economical means of remediation by identifying areas or crack mechanisms that contribute most to the probability of failure.

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