Cyclic behaviour of 12% Cr ferritic-martensitic steel upon long-term on-site service in power plants

Small-diameter tubes that are widely used in petroleum industries and power plants experience corrosion during long-term services. In this paper, a compact inserted guided-wave EMAT with a pulsed electromagnet is proposed for small-diameter tube inspection. The proposed transducer is noncontact, compact with high signal-to-noise ratio and unattractive to ferromagnetic tubes. The proposed EMAT is designed with coils-only configuration, which consists of a pulsed electromagnet and a meander pulser/receiver coil. Both the numerical simulation and experimental results validate its feasibility on generating and receiving L(0,2) mode guided wave. The parameters for driving the proposed EMAT are optimized by performance testing. Finally, feasibility on quantification evaluation for corrosion defects was verified by experiments.

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A Combined Approach for Model-Based PV Power Plant Failure Detection and Diagnostic

Energies ◽

10.3390/en14051261 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1261

Author(s):

Christopher Gradwohl ◽

Vesna Dimitrievska ◽

Federico Pittino ◽

Wolfgang Muehleisen ◽

András Montvay ◽

...

Keyword(s):

Power Plants ◽

Large Scale ◽

Failure Detection ◽

Energy Yield ◽

Combined Approach ◽

Levelized Cost Of Electricity ◽

Term Operation ◽

Model Based

Photovoltaic (PV) technology allows large-scale investments in a renewable power-generating system at a competitive levelized cost of electricity (LCOE) and with a low environmental impact. Large-scale PV installations operate in a highly competitive market environment where even small performance losses have a high impact on profit margins. Therefore, operation at maximum performance is the key for long-term profitability. This can be achieved by advanced performance monitoring and instant or gradual failure detection methodologies. We present in this paper a combined approach on model-based fault detection by means of physical and statistical models and failure diagnosis based on physics of failure. Both approaches contribute to optimized PV plant operation and maintenance based on typically available supervisory control and data acquisition (SCADA) data. The failure detection and diagnosis capabilities were demonstrated in a case study based on six years of SCADA data from a PV plant in Slovenia. In this case study, underperforming values of the inverters of the PV plant were reliably detected and possible root causes were identified. Our work has led us to conclude that the combined approach can contribute to an efficient and long-term operation of photovoltaic power plants with a maximum energy yield and can be applied to the monitoring of photovoltaic plants.

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Quantification of PV Power and Economic Losses Due to Soiling in Qatar

Sustainability ◽

10.3390/su13063364 ◽

2021 ◽

Vol 13 (6) ◽

pp. 3364

Author(s):

Amr Zeedan ◽

Abdulaziz Barakeh ◽

Khaled Al-Fakhroo ◽

Farid Touati ◽

Antonio S. P. Gonzales

Keyword(s):

Output Power ◽

Power Plants ◽

Economic Loss ◽

Economic Losses ◽

Energy Yield ◽

Solar Pv ◽

Financial Loss ◽

Grid Systems ◽

Dust Density

Soiling losses of photovoltaic (PV) panels due to dust lead to a significant decrease in solar energy yield and result in economic losses; this hence poses critical challenges to the viability of PV in smart grid systems. In this paper, these losses are quantified under Qatar’s harsh environment. This quantification is based on experimental data from long-term measurements of various climatic parameters and the output power of PV panels located in Qatar University’s Solar facility in Doha, Qatar, using a customized measurement and monitoring setup. A data processing algorithm was deliberately developed and applied, which aimed to correlate output power to ambient dust density in the vicinity of PV panels. It was found that, without cleaning, soiling reduced the output power by 43% after six months of exposure to an average ambient dust density of 0.7 mg/m3. The power and economic loss that would result from this power reduction for Qatar’s ongoing solar PV projects has also been estimated. For example, for the Al-Kharasaah project power plant, similar soiling loss would result in about a 10% power decrease after six months for typical ranges of dust density in Qatar’s environment; this, in turn, would result in an 11,000 QAR/h financial loss. This would pose a pressing need to mitigate soiling effects in PV power plants.

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Simulation of MASPn Experiments in MISTRA Test Facility with COCOSYS Code

Science and Technology of Nuclear Installations ◽

10.1155/2008/896406 ◽

2008 ◽

Vol 2008 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Mantas Povilaitis ◽

Egidijus Urbonavičius

Keyword(s):

Boundary Conditions ◽

Nuclear Power ◽

Power Plants ◽

Volume Fraction ◽

Characteristic Length ◽

Initial Conditions ◽

Test Facility ◽

Work Package ◽

Acceptable Agreement

An issue of the stratified atmospheres in the containments of nuclear power plants is still unresolved; different experiments are performed in the test facilities like TOSQAN and MISTRA. MASPn experiments belong to the spray benchmark, initiated in the containment atmosphere mixing work package of the SARNET network. The benchmark consisted of MASP0, MASP1 and MASP2 experiments. Only the measured depressurisation rates during MASPn were available for the comparison with calculations. When the analysis was performed, the boundary conditions were not clearly defined therefore most of the attention was concentrated on MASP0 simulation in order to develop the nodalisation scheme and define the initial and boundary conditions. After achieving acceptable agreement with measured depressurisation rate, simulations of MASP1 and MASP2 experiments were performed to check the influence of sprays. The paper presents developed nodalisation scheme of MISTRA for the COCOSYS code and the results of analyses. In the performed analyses, several parameters were considered: initial conditions, loss coefficient of the junctions, initial gradients of temperature and steam volume fraction, and characteristic length of structures. Parametric analysis shows that in the simulation the heat losses through the external walls behind the lower condenser installed in the MISTRA facility determine the long-term depressurisation rate.

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Long-term corrosion behavior of martensitic steel welds in static molten Pb–17Li alloy at 550°C

Corrosion Science ◽

10.1016/j.corsci.2015.04.001 ◽

2015 ◽

Vol 96 ◽

pp. 178-185 ◽

Cited By ~ 18

Author(s):

Xizhang Chen ◽

Qibing Yuan ◽

Bruce Madigan ◽

Wei Xue

Keyword(s):

Corrosion Behavior ◽

Martensitic Steel ◽

Steel Welds

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The PLC Research in the Program Control System of Thermal Power Coal Handling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.548.812 ◽

2012 ◽

Vol 548 ◽

pp. 812-816

Author(s):

Xiao Min Chen ◽

Xi Yan Liu

Keyword(s):

Power Plants ◽

Rapid Development ◽

Thermal Power ◽

Chinese Economy ◽

Power Requirement ◽

Handling System ◽

Human Power ◽

Material Resources ◽

Electricity System

With the rapid development of Chinese economy, the thermal power requirement is increasing not only in industry but also for the civil use in recent years. In China, the main fuel of thermal power is coal. Coal handling system places the consequence in the whole generate electricity system and has significant meaning to the power plant operation. The coal handling system of the thermal power plants has many types of equipment. The environment is vile with complicated control. If we control this system through manual mode, there will appear the imponderable questions. This article through the research of the coal handling system by the management of PLC can determine the long-term safe operation and reduce a mass of human power and material resources. It has the fundamental practical meaning and research value.

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Tackling Complexity of the Just Transition in the EU: Evidence from Romania

Energies ◽

10.3390/en14051509 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1509

Author(s):

Roxana Voicu-Dorobanțu ◽

Clara Volintiru ◽

Maria-Floriana Popescu ◽

Vlad Nerău ◽

George Ștefan

Keyword(s):

Environmental Sustainability ◽

Power Plants ◽

Point Of View ◽

Major Power ◽

Complex Issue ◽

Energy Mix ◽

Carbon Neutrality ◽

Vulnerable Consumers ◽

The Eu

The process of reaching carbon neutrality by 2050 and cutting CO2 emissions by 2030 by 55% compared to 1990 as per the EU Green Deal is highly complex. The energy mix must be changed to ensure long-term environmental sustainability, mainly by closing down coal sites, while preserving the energy-intensive short-term economic growth, ensuring social equity, and opening opportunities for regions diminishing in population and potential. Romania is currently in the position of deciding the optimal way forward in this challenging societal shift while morphing to evidence-based policy-making and anticipatory governance, mainly in its two coal-mining regions. This article provides possible future scenarios for tackling this complex issue in Romania through a three-pronged, staggered, methodology: (1) clustering Romania with other similar countries from the point of view of the Just Transition efforts (i.e., the energy mix and the socio-economic parameters), (2) analyzing Romania’s potential evolution of the energy mix from the point of the thermal efficiency of two major power plants (CEH and CEO) and the systemic energy losses, and (3) providing insights on the socio-economic context (economic development and labor market transformations, including the component on the effects on vulnerable consumers) of the central coal regions in Romania.

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Estimating Long Term Major Maintenance and Capital Spending Requirements of Trinidad’s Aging Power Plants

ASME 2006 Power Conference ◽

10.1115/power2006-88144 ◽

2006 ◽

Author(s):

Robert R. Richwine ◽

Michael Joseph ◽

Charles Huguenard ◽

Hafeez Baksh ◽

Mike Elenbass

Keyword(s):

Power Plants ◽

Probabilistic Approach ◽

Risk Profile ◽

Periodic Review ◽

Total Cost ◽

Financial Decisions ◽

Capital Spending ◽

Generation Company ◽

Insight Into

This paper describes the process used by the Power Generation Company of Trinidad and Tobago (PowerGen) to estimate the range of major (expenditures greater than US$50,000) recurring and non-recurring costs that can be expected to be incurred from 2006–2025 by PowerGen’s three existing generating facilities: Port of Spain, Point Lisas and Penal. Since many of these Capital and O&M costs are not 100% certain, a probabilistic approach was used that incorporates a Monte Carlo methodology. The results of this approach allowed PowerGen to better understand the range of possible major capital and O&M expenditures that would likely be required over the next 20 years along with a quantification of the risk profile of those ranges. By adding these costs to the routine O&M costs, a total cost cash flow timeline was able to be developed that more realistically forecast the actual financial requirements of PowerGen’s power plants. Periodic review and updates of the data will also provide PowerGen with a continuing sound basis for long term technical and financial decisions. Additionally, a benchmarking analysis was performed that compared the reliability trends of similar but older technologies to those plants in PowerGen’s fleet in order to gain an insight into the reliability expectations for PowerGen plants over the next twenty years.

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