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

A Case Study in Cellular Cofferdam Life Extension Design

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

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.

Upgrade and Life Extension of 4 × 110 MW Units: A Case Study

2004 ◽  
Author(s):  
Nynar Ayodhi ◽  
Y. Radhakrishnamurthy
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Heat Rate ◽  
Life Extension ◽  
Load Factor ◽  
Fuel Quality ◽  
Gas Temperature ◽  
Increasing Trend ◽  
Key Issues

Achieving rated capacity and economical operation of existing thermal power plants are vital issues for utilities. Plants nearing their design life are likely to show declining trend in availability as well as increasing trend in operation and maintenance costs due to ageing. Constraints in system adequacy, decreasing trend in efficiency and poor reliability are key issues to be addressed while planning life extension. 4×110 MW power plant located in southern part of India has been taken up for renovation and modernization. Pressure parts failures mainly accounted for the reduced availability of the units. The exit gas temperature in boiler was on the higher side leading to operation of the units with reduced efficiency. Change in fuel quality over the years as compared to what has been considered during design was a constraint in achieving rated capacity. The poor heat rate of turbine necessitated incorporation of the state-of-art design to achieve better heat rate. Improvements required in control and instrumentation system were also addressed in the renovation and modernization. Improvements in plant load factor, availability and unit heat rate could be achieved in the two units where renovation and modernization has been completed. The details of the renovation and modernization of these units are discussed in this paper.

Fatigue Reassessment to Modern Standards for Life Extension of Offshore Pressure Vessels

2015 ◽  
Author(s):  
Emily Hutchison ◽  
John Wintle ◽  
Alison O’Connor ◽  
Emilie Buennagel ◽  
Clement Buhr
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Pressure Vessels ◽  
Life Extension ◽  
Offshore Platforms ◽  
Design Standards ◽  
Element Analysis ◽  
Gas Industry ◽  
Lack Of Information

Life extension of ageing assets is becoming increasingly important for the offshore oil and gas industry. Many pressure vessels in service have reached or are about to reach the end of their design lives, but their continued operation is required until the economic field life is exhausted. Many vessels in-service were designed over 30 years ago, when fatigue assessment was not required by the design standards. Therefore, fatigue reassessment is a critical part of the life extension process. This paper presents reassessment of a benchmark vessel as a case study for life extension of other similar vessels. Life extension assessments are costly and time consuming, often hindered by a lack of information and a lack of access to the vessels. By determining the commonality between a vessel and the benchmark vessel, it may be possible with suitable on-going in-service inspection to justify life extension of the vessel without the need for a full fatigue life extension reassessment in every case. The case study considered in this paper is a condensate flash separator vessel constructed in the early 70s which was in operation for 25 years; and is similar to many pressure vessels still in service on offshore platforms. The fatigue lives of key features of the vessel have been calculated and compared using different modern pressure vessel design codes, supported by finite element analysis.

Improving Component Life Prediction Accuracy and Reliability Through Physics Based Prognosis: A Probabilistic Turbine Blade Case Study

2008 ◽  
Author(s):  
Ashok K. Koul ◽  
Saurabh Bhanot ◽  
Ajay Tiku ◽  
Brent Junkin
Keyword(s):  
Life Prediction ◽  
Residual Life ◽  
Turbine Blades ◽  
Operating Conditions ◽  
Life Extension ◽  
Inlet Temperature ◽  
Damage Analysis ◽  
Creep Life ◽  
Critical Locations

The paper presents the results of a probabilistic creep life study on RRA 501 KB turbine blades and demonstrates the importance of using physics based probabilistic damage modeling techniques to deal with life prediction uncertainty in cast equiaxed components. It is shown that physics based damage analysis yields accurate results and considerably less mechanical properties data is needed for life prediction of cast components. In physics based damage analysis, it is also easy to quickly assess the life limiting damage modes and to establish fracture critical locations in components. In physics based modeling, the influence of individual microstructural or thermal-mechanical loading factors on metallurgical crack nucleation can also be studied with relative ease. Residual life of service exposed parts and effectiveness of life extension techniques can also be predicted because the state of microstructure due to prior service and repair can be taken into account. In this study, Life Prediction Technologies Inc.’s (LPTi’s) prognosis tool known as XactLIFE™ was successfully used to establish the fracture critical location of RRA 501KB first stage gas turbine blades under steady state loads. Deterministic analysis was first used to compute the lower bound airfoil nodal creep life of the various finite element nodes and this was followed by probabilistic creep life analysis to take into account the variability of microstructure from one blade to another. The analysis used typical engine operating data from the field in terms of engine speed and average turbine inlet temperature (TIT). The primary objectives of the case study are to show how prognosis can allow a user to predict component fracture critical locations, establish inspection intervals to avoid failures and establish fleet reliability for engine specific operating conditions.

scholarly journals Life Extension of Electronic Products: A Case Study of Smartphones

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 144726-144739
Author(s):  
Dylan A. Hazelwood ◽  
Michael G. Pecht
Keyword(s):  
Life Extension ◽  
Electronic Products

Structural Integrity Assessment of Aging Fixed Steel Offshore Jacket Platforms: A Persian Gulf Case Study

2013 ◽  
Author(s):  
Hamid Golpour ◽  
Mostafa Zeinoddini ◽  
Hadi Khalili ◽  
Ali Golbaz ◽  
Yashar Yaghubi ◽  
...  
Keyword(s):  
Persian Gulf ◽  
Structural Model ◽  
Structural Integrity ◽  
Global Analysis ◽  
Life Extension ◽  
Offshore Platforms ◽  
Perspective View ◽  
Integrity Assessment ◽  
Fit For Purpose

The existing knowledge on the structural integrity assessment of offshore platforms may benefit from case studies on the life extension evaluations of aging structures. This paper presents a case study for the structural integrity assessment of an existing 8 legged aging drilling platform located in the Persian Gulf. The platform is now 42 years old and the objective of the study is to check its fit for purpose for a life extension of 25 years beyond 2012. The structural model is based on the best estimates of the existing conditions of the platform. A number of analysis approach such as i) assessment based on the previous exposures, ii) linear (elastic), iii) equivalent linear (or the linear global analysis with local overload considerations), and iv) non-linear analysis methods have been used to estimate the structural integrity of the platform. The paper provides further background, clarifications and proposed updates to API-RP 2A-Section 17. The paper is divided into three parts. Section 1 is a discussion on the background of the previous assessment study and perspective view on why the case study platform needs to be assessed. Section 2 and Section 3 include the finding of the code-noncompliance points of the platform based on the recommendations of API RP 2A-2007. Section 4 presents the remedy actions recommended for the fit for purpose of the platform.

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