scholarly journals Gas Turbine Rotor Disc Repair-Case History

1998 ◽  
Author(s):  
Zdzislaw Mazur ◽  
Janusz Kubiak
Keyword(s):  
Gas Turbine ◽  
Stress Relief ◽  
Repair Process ◽  
Turbine Rotor ◽  
Second Stage ◽  
Welding Technology ◽  
Disc Repair ◽  
Stage 1 ◽  
In Situ Repair

The 20.65 MW gas turbine experienced catastrophic damage. The failure occurred at the first stage buckets and resulted in damage of the all buckets of this stage. Five rotor disc grooves were also seriously damaged. Additionally, all second stage buckets, first and second stage nozzles, shroud segments, the No 2 bearing casing (turbine side), compressor moving blades, and other elements were damaged. Due to urgent power generation needs, it was decided to repair a seriously damaged stage 1 rotor disc in-situ, and replace all the other damaged parts. The development of a propietary welding technology for the in-situ repair of the five damaged disc grooves without disc disassembly, and of in-situ disc grooves’ mechanized machining is fully described. The repair process included the removal of damaged grooves, method of groove restoration by welding deposition, stress relief and groove machining to recover their original geometry. After rotor disc repair and assembly, the rotor was put back into service. The approach to the repair of the rotor disc damage has been successful. It enabled significant reductions in expenditure on replacement parts and a reduction of outage time to be achived.

scholarly journals Repairability analysis of the energy gas turbine rotor blade second stage shroud by high-temperature brazing

2021 ◽  
Vol 93 (2) ◽  
pp. 23-31
Author(s):  
Piotr Klimczuk
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Gas Turbine ◽  
Rotor Blade ◽  
Repair Process ◽  
Turbine Rotor ◽  
Turbine Rotor Blade ◽  
Second Stage ◽  
Honeycomb Seals ◽  
Scanning Electron

The article considers the repair of the energy gas turbine rotor blade second stage shroud. The paper presents an analysis of the possibility of the repair consisting of the replacement of both labyrinth and honeycomb seals by the high-temperature brazing process. All the steps of the repair process were discussed and the results of microscopic metallographic evaluation using a light microscope and a scanning electron microscope were presented. Several advantages related to the use of this technology were indicated.

How well do voice-hearing assessment measures capture the positive experiences of individuals?

2019 ◽  
Author(s):  
Lucy Armstrong ◽  
Lorna Hogg ◽  
Pamela Charlotte Jacobsen
Keyword(s):  
Systematic Review ◽  
Lived Experience ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Hearing Assessment ◽  
Positive Experiences ◽  
Assessment Measures ◽  
Stage 1 ◽  
The Voice

The first stage of this project aims to identify assessment measures which include items on voice-hearing by way of a systematic review. The second stage is the development of a brief framework of categories of positive experiences of voice hearing, using a triangulated approach, drawing on views from both professionals and people with lived experience. The third stage will involve using the framework to identify any positve aspects of voice-hearing included in the voice hearing assessments identified in stage 1.

In-Situ Study of Ti/TiN Stability under Nitrogen Anneal

1999 ◽  
Vol 564 ◽  
Author(s):  
P. W. DeHaven ◽  
K. P. Rodbell ◽  
L. Gignac
Keyword(s):  
Annealing Temperature ◽  
Time Range ◽  
Second Phase ◽  
Transformation Rate ◽  
Transformation Mechanism ◽  
Second Stage ◽  
Transmission Electron ◽  
Reaction Proceeds ◽  
Two Stages

AbstractThe effectiveness of a TiN capping layer to prevent the conversion of α-titantium to titanium nitride when annealed in a nitrogen ambient has been studied over the temperature range 300–700°C using in-situ high temperature diffraction and transmission electron microscopy. Over the time range of interest (four hours), no evidence of Ti reaction was observed at 300°C. At 450°C. nitrogen was found to diffuse into the Ti to form a Ti(N) solid solution. Above 500°C the titanium is transformed to a second phase: however this reaction follows two different kinetic paths, depending on the annealing temperature. Below 600°C. the reaction proceeds in two stages, with the first stage consisting of Ti(N) formation, and the second stage consisting of the conversion of the Ti(N) with a transformation mechanism characteristic of short range diffusion (grain edge nucleation). Above 600°C, a simple linear transformation rate is observed.

The Microstructure and Mechanical Properties of Ni-Based Superalloy after Service Exposure in Gas Turbine

2010 ◽  
Vol 654-656 ◽  
pp. 2523-2526 ◽  
Author(s):  
Keun Bong Yoo ◽  
Han Sang Lee
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Mechanical Tests ◽  
Time Dependent ◽  
Second Stage ◽  
Degradation Analysis ◽  
Check Points ◽  
Tcp Phase ◽  
Service Exposure ◽  
High Temperature Tensile

Many investigations about superalloys and coatings have been done in the laboratory, but evaluating the degradation condition of hot section components during service is still important not only for repair and reuse but also for outage prevention. Time dependent degradation for second stage blades of gas turbine was investigated. The degradation analysis for used blades was divided into microstructure changes by position of the blade and mechanical tests of high temperature tensile test. In the microstructure analysis, the rafting and coarsening of γ', MC decomposition and TCP phase formation occurred and progressed with increasing service time, and especially the leading and trailing edge of top layer should be a check points for used blade. High temperature tensile results of 25,000 and 52,000 hrs used blades were also compared with serviced time and position in each blade.

scholarly journals Outcomes of In Situ Repair for Treatment of Arteriovenous Fistula Aneurysm

2021 ◽  
Vol 74 (3) ◽  
pp. e201-e202
Author(s):  
Hunter M. Ray ◽  
Yuki Ikeno ◽  
Jacob Siahaan ◽  
Kristofer Charlton-Ouw
Keyword(s):  
Arteriovenous Fistula ◽  
In Situ Repair

Fast in-situ repair technology-a novel SPS process for the waste refractory W–10Ti targets

Vacuum ◽  
2021 ◽  
pp. 110406
Author(s):  
Lei Huang ◽  
Yafei Pan ◽  
Jiuxing Zhang ◽  
Yong Du ◽  
Yuhui Zhang ◽  
...  
Keyword(s):  
Repair Technology ◽  
In Situ Repair

In-situ Repair of Marine Coatings by a Fe3O4 Nanoparticle-Modified Epoxy Resin under Seawater

2021 ◽  
pp. 132827
Author(s):  
Zhenliang Feng ◽  
Rongjian Wan ◽  
Shiming Chen ◽  
Xiao Tang ◽  
Hong Ju ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Fe3o4 Nanoparticle ◽  
Marine Coatings ◽  
Modified Epoxy ◽  
In Situ Repair

Comparison of 3D Unsteady Transient Conjugate Heat Transfer Analysis on a High Pressure Cooled Turbine Stage With Experimental Data

2017 ◽  
Author(s):  
Jong-Shang Liu ◽  
Mark C. Morris ◽  
Malak F. Malak ◽  
Randall M. Mathison ◽  
Michael G. Dunn
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Flux ◽  
High Pressure ◽  
High Temperature ◽  
Gas Turbine ◽  
Conjugate Heat Transfer ◽  
Turbine Rotor ◽  
Turbine Stage ◽  
Cooling Flow

In order to have higher power to weight ratio and higher efficiency gas turbine engines, turbine inlet temperatures continue to rise. State-of-the-art turbine inlet temperatures now exceed the turbine rotor material capability. Accordingly, one of the best methods to protect turbine airfoil surfaces is to use film cooling on the airfoil external surfaces. In general, sizable amounts of expensive cooling flow delivered from the core compressor are used to cool the high temperature surfaces. That sizable cooling flow, on the order of 20% of the compressor core flow, adversely impacts the overall engine performance and hence the engine power density. With better understanding of the cooling flow and accurate prediction of the heat transfer distribution on airfoil surfaces, heat transfer designers can have a more efficient design to reduce the cooling flow needed for high temperature components and improve turbine efficiency. This in turn lowers the overall specific fuel consumption (SFC) for the engine. Accurate prediction of rotor metal temperature is also critical for calculations of cyclic thermal stress, oxidation, and component life. The utilization of three-dimensional computational fluid dynamics (3D CFD) codes for turbomachinery aerodynamic design and analysis is now a routine practice in the gas turbine industry. The accurate heat-transfer and metal-temperature prediction capability of any CFD code, however, remains challenging. This difficulty is primarily due to the complex flow environment of the high-pressure turbine, which features high speed rotating flow, coupling of internal and external unsteady flows, and film-cooled, heat transfer enhancement schemes. In this study, conjugate heat transfer (CHT) simulations are performed on a high-pressure cooled turbine stage, and the heat flux results at mid span are compared to experimental data obtained at The Ohio State University Gas Turbine Laboratory (OSUGTL). Due to the large difference in time scales between fluid and solid, the fluid domain is simulated as steady state while the solid domain is simulated as transient in CHT simulation. This paper compares the unsteady and transient results of the heat flux on a high-pressure cooled turbine rotor with measurements obtained at OSUGTL.

In situ repair technique of infill masonry walls in steel frames damaged after an earthquake

2019 ◽  
Vol 178 ◽  
pp. 665-679 ◽  
Author(s):  
Mohammad Soheil Ghobadi ◽  
Roohollah Ahmady Jazany ◽  
Hamidreza Farshchi
Keyword(s):  
Steel Frames ◽  
Masonry Walls ◽  
Repair Technique ◽  
Infill Masonry ◽  
In Situ Repair
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