Cryogenic Tanks Recertification: Case Study for Operational-Life Extension

2015 ◽  
Vol 4 (04) ◽  
pp. 088-100
Author(s):  
Adib Soufiane Adamou
Keyword(s):  
Life Extension ◽  
Operational Life ◽  
Cryogenic Tanks

scholarly journals Life extension of UAVs: a case study of Indian UAVs

2019 ◽  
Vol 14 ◽  
pp. 184-190
Author(s):  
Manu Jain ◽  
S Rajashekar ◽  
R Vasantha ◽  
V Subramanian ◽  
V Maharajan ◽  
...  
Keyword(s):  
Life Extension

THE LIFE ASSESSMENT OF STEAM TURBINE ROTORS FOR FOSSIL POWER PLANTS

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4371-4376
Author(s):  
SUNGHO CHANG ◽  
GEEWOOK SONG ◽  
BUMSHIN KIM ◽  
JUNGSEB HYUN ◽  
JEONGSOO HA
Keyword(s):  
Power Plant ◽  
Steam Turbine ◽  
Rotational Speed ◽  
Power Plants ◽  
Thermal Power ◽  
Creep Damage ◽  
Life Assessment ◽  
Life Extension ◽  
Start Up ◽  
Operational Life

The operational mode of thermal power plants has been changed from base load to duty cycle. From the changeover, fossil power plants cannot avoid frequent thermal transient states, for example, start up and stop, which results in thermal fatigue damage at the heavy section components. The rotor is the highest capital cost component in a steam turbine and requires long outage for replacing with a new one. For an optimized power plant operational life, inspection management of the rotor is necessary. It is known in general that the start-up and shutdown operations greatly affect the steam turbine life. The start-up operational condition is especially severe because of the rapid temperature and rotational speed increase, which causes damage and reduction of life of the main components life of the steam turbine. The start-up stress of a rotor which is directly related to life is composed of thermal and rotational stresses. The thermal stress is due to the variation of steam flow temperature and rotational stress is due to the rotational speed of the turbine. In this paper, the analysis method for the start-up stress of a rotor is proposed, which considers simultaneously temperature and rotational speed transition, and includes a case study regarding a 500MW fossil power plant steam turbine rotor. Also, the method of quantitative damage estimation for fatigue-creep damage to operational conditions, is described. The method can be applied to find weak points for fatigue-creep damage. Using the method, total life consumption can be obtained, and can be also be used for determining future operational modes and life extension of old fossil power units.

A Case Study in Cellular Cofferdam Life Extension Design

Ports 2013 ◽  
2013 ◽  
Author(s):  
Jeffery R. Basford ◽  
Matthew A. McCarty
Keyword(s):  
Life Extension

Incorporating Environmental Impacts in Strategic Redesign of an Engineered System

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Steven R. Harper ◽  
Deborah L. Thurston
Keyword(s):  
Environmental Impacts ◽  
Early Retirement ◽  
Power Plants ◽  
Electrical Power ◽  
Decision Rules ◽  
Life Cycles ◽  
Life Extension ◽  
Electrical Power System ◽  
Term Operation ◽  
Operational Life

Large engineered systems do not often live out their life cycles as originally planned. Traditional design methods do not address redesign issues that arise during long term operation of these systems. The problem of how to consider the environmental impacts of stranded assets is especially problematic, particularly during system operational changes. This paper presents a method for analysis of a dynamically changing system that includes consideration of both economic and environmental impacts. A case study of an electrical power system illustrates the approach. Using a 100yr time period and using several decision rules (e.g., keep all plants operating until planned retirement age or retire all plants 10% early), the aggregated results were derived. The best sequence of decision or decision rule can now be determined by the highest multiattribute utility score. The best decision sequence is one that immediately retires and decommissions all fossil fueled electrical power plants, although early retirement without immediate decommissioning produces inferior utility values. There is little gained in utility when extending operational life of the plants, and as the 100yr period moves forward, all solutions collapse on the final system configuration. The results provide several insights that were gained through the ability to forecast the environmental impact caused by changes within the life cycle phases of a system, such as early retirement or operational life extension of facilities.

Case Study of Full-Length Tube Coating and Condenser Life Extension

2013 ◽  
Author(s):  
Keith Pearson ◽  
Larry Hill ◽  
Michael Horn ◽  
James Mitchell
Keyword(s):  
Natural Gas ◽  
Heat Rate ◽  
Full Length ◽  
Life Extension ◽  
Coating Process ◽  
Condenser Tube

In the Spring of 2012 a 1950’s vintage natural gas unit located on a lake in Texas encountered multiple condenser tube failures of its Admiralty Brass tubes. Due to time and cost restraints, the option of retubing was not chosen to prepare the unit for the summer run. Instead, the full-length of approximately 5,500 tubes were epoxy coated. This included 1,150 tubes which had been plugged as leakers, but were unplugged and coated using a special leak sealing method of applying the epoxy lining. The coating process was completed in 10 days and all but 55 tubes were sealed by the coating process. These tubes were plugged and the unit was put into service. The unit has been running successfully since the project was completed with no heat rate penalty. The circumstances leading up to this situation are discussed along with the details of the coating process.

scholarly journals Validation of a structural model of an aircraft cockpit panel: An industrial case study

2021 ◽  
pp. 030932472110590
Author(s):  
Eann A Patterson ◽  
Ioannis Diamantakos ◽  
Ksenija Dvurecenska ◽  
Richard J Greene ◽  
Erwin Hack ◽  
...  
Keyword(s):  
Laboratory Study ◽  
Real World ◽  
Computational Models ◽  
Structural Model ◽  
Complex Structure ◽  
Image Correlation ◽  
Validation Process ◽  
The Real ◽  
Operational Life

Computational models of structures are widely used to inform decisions about design, maintenance and operational life of engineering infrastructure, including airplanes. Confidence in the predictions from models is provided via validation processes that assess the extent to which predictions represent the real world, where the real world is often characterised by measurements made in experiments of varying sophistication dependent on the importance of the decision that the predictions will inform. There has been steady progress in developing validation processes that compare fields of predictions and measurements in a quantitative manner using the uncertainty in measurements as a basis for assessing the importance of differences between the fields of data. In this case study, three recent advances in a validation process, which was evaluated in an inter-laboratory study 5 years ago, are implemented using a ground-test on a fuselage at the aircraft manufacturer’s site for the first time. The results show that the advances successfully address the issues raised by the inter-laboratory study, that the enhanced validation process can be implemented in an industrial environment on a complex structure, and that the model was an excellent representation of the measurements made using digital image correlation.

STI Punch-through Degradation Related Standby Current Failure in HTOL Test – A Case Study

2007 ◽  
Author(s):  
Wen-Rong Chen ◽  
Wei-Chun Tseng ◽  
Yi-Ju Lee ◽  
Kuang-Wen Liu ◽  
Li-Kuang Kuo ◽  
...  
Keyword(s):  
High Temperature ◽  
Failure Mechanisms ◽  
Circuit Layout ◽  
Shallow Trench Isolation ◽  
Operational Life ◽  
Trench Isolation ◽  
Electrical Analysis ◽  
Stress Experiment

Abstract This report summarizes the analysis results of 0.13µm technology 256Mbits NBit HTOL (High Temperature Operational Life) induced standby current failures caused by STI (Shallow Trench Isolation) punch through induced leakage degradation. Electrical analysis, EMMI and stress experiment on test devices are employed to identify the failure mechanisms, root causes, and corrective solutions. From this study, improvements could be achieved by circuit layout modification.

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