Technological and economical consideration for turbine blade tip restoration through metal deposition technologies

2019 ◽  
pp. 095440621988824
Author(s):  
A Ciappi ◽  
A Giorgetti ◽  
F Ceccanti ◽  
G Canegallo
Keyword(s):  
Gas Turbines ◽  
Failure Modes ◽  
Turbine Blades ◽  
Oil And Gas Industry ◽  
Technology Selection ◽  
Cold Metal Transfer ◽  
Original Equipment Manufacturer ◽  
Equipment Manufacturer ◽  
Blade Tip ◽  
Economical Consideration

In the oil and gas industry, repair activities are critical to keep the maintenance costs of turbomachinery equipment down. Several repair technologies can be applied to various components of turbomachines. When dealing with gas turbines, the repair of turbine rotor blades has always been a very sensitive topic, given their critical application and their impact in terms of cost on the whole turbine lifecycle. Specifically, cracking and wearing of blade tips are some of the most common failure modes. Thus, the repair of these failure modes is of paramount importance, both for the original manufacturer as well as its aftermarket competitors. The present paper describes blade tip repair technologies from an original equipment manufacturer standpoint. Three different approaches are introduced and described for tip restoration. Laser cladding is presented first, since it is one of the most common technologies for this application, and then original equipment manufacturer which is currently being applied is presented. Then, cold metal transfer and direct metal laser melting technologies are investigated. A technologic and financial assessment is made to drive the technology selection for the turbine blades restoration.

A New Analytical Model for Interpreting the Wear Mechanisms of Abradable Seal Systems and Verification by Testing

1989 ◽  
Author(s):  
J. Soehngen
Keyword(s):  
Heat Flux ◽  
High Temperature ◽  
Analytical Model ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Ceramic Materials ◽  
Analytical Prediction ◽  
Material Loss ◽  
Blade Tip ◽  
Engine Components

In order to minimize the specific fuel consumption of gas turbines it is necessary to increase the gas temperatures and pressure ratios. Therefore, new high-temperature resistant abradable seal systems must be developed, especially for the hot section. Since the required operating temperatures are above 1050°C, the use of metallic materials as abradables is out of the question. A problem commonly encountered in the selection of new (ceramic) materials for seal systems is that of insufficient knowledge of the tribological process occurring when turbine blades rub against an abradable seal. The purpose of the investigation was to find a simplified analytical model to describe the tribological process occurring in the rubbing of the blades against the seal, in order to help in the preselection of materials for abradable seals. The model was verified by testing high-temperature resistant abradable seals under simulated engine conditions, followed by metallurgical examination. The results of the examination of two abradable seals on run engine components confirmed the analytical prediction and laboratory tests. The differences in material loss from the blade and the abradable seal can be correlated to the heat flux distribution in the sliding parts. Using different materials on the blade tip and stationary seal (e.g. ceramic blade tip and ceramic or metallic abradable seal), the heat flux can be directed in such a way that the wear takes place largely on the static part of the engine. By calculating their relative abradability, material combinations with optimum performance for each seal application can be found.

Turbine Tip Clearance Measurement System Evaluation on an Industrial Gas Turbine

1997 ◽  
Author(s):  
S. J. Gill ◽  
M. D. Ingallinera ◽  
A. G. Sheard
Keyword(s):  
Gas Turbine ◽  
Measurement System ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Tip Clearance ◽  
Real Time Measurement ◽  
Gap Measurement ◽  
Industrial Gas Turbines ◽  
Blade Tip ◽  
Industrial Gas Turbine

The continuing development of industrial gas turbines is resulting in machines of increasing power and efficiency. The need to continue this trend is focusing attention on minimizing all loss mechanisms within the machine, including those associated with turbine blade tip clearance. In order to study tip clearance in the turbine, real time measurement is required of clearance between turbine blades and the casing in which they run. This measurement is not routinely performed, due to the harsh nature of the turbine environment. On those occasions when turbine tip clearance is measured, it is typically in development vehicles, often using cooled probes that are somewhat unsuitable for use in production gas turbines. In this paper a program of work is reported that was undertaken with the purpose of identifying a promising turbine tip clearance measurement system that used the capacitive gap measurement technique. Issues surrounding the application of three systems to the turbine section of a GE MS6001FA gas turbine are identified and reported. Performance of the three evaluated systems is analyzed.

Impact of Passive Tip-Injection on the Performance of Partially Shrouded Turbines: Basic Concept and Preliminary Results

2013 ◽  
Author(s):  
Pouya Ghaffari ◽  
Reinhard Willinger
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Tip Leakage Flow ◽  
Tip Leakage ◽  
Blade Tip ◽  
Tip Injection ◽  
The Impact

In terms of efficiency improvement many methods for reducing the blade tip-leakage mass flow rate have been proposed. Some of these methods are based on increasing the flow resistance with aid of geometrical modifications of the blade tip (squealers, winglets, shrouded blades, etc.) whereas other methods take advantage of aerodynamical resistance with passive tip-injection as an example. The objective of this paper is a combination of both methods in order to achieve higher reduction in tip-leakage mass flow rate. In the first part of this work necessary characteristic parameters of modern low pressure turbine blades in aircraft gas turbines are estimated. These parameters are taken into consideration to calculate the range of physical quantities influencing tip-leakage flow. Subsequently a two dimensional flow model is obtained with the so called discharge coefficient as the ratio of the actual tip gap mass flow rate to its highest possible value. The investigations are based on dimensionless calculations. In the end the results obtained from dimensionless 2D CFD-simulations are presented and compared with the analytical results. This leads to conclusions regarding the impact of various parameters on the effectiveness of the passive tip-injection.

Improving Efficiency in Robot Assisted Belt Grinding of High Performance Materials

2014 ◽  
Vol 907 ◽  
pp. 139-149 ◽  
Author(s):  
Eckart Uhlmann ◽  
Florian Heitmüller
Keyword(s):  
Gas Turbines ◽  
High Performance ◽  
Scale Effects ◽  
Turbine Blades ◽  
Repair Process ◽  
Industrial Robots ◽  
Robot Assisted ◽  
Belt Grinding ◽  
Economy Of Scale ◽  
The Individual

In gas turbines and turbo jet engines, high performance materials such as nickel-based alloys are widely used for blades and vanes. In the case of repair, finishing of complex turbine blades made of high performance materials is carried out predominantly manually. The repair process is therefore quite time consuming. And the costs of presently available repair strategies, especially for integrated parts, are high, due to the individual process planning and great amount of manually performed work steps. Moreover, there are severe risks of partial damage during manually conducted repair. All that leads to the fact that economy of scale effects remain widely unused for repair tasks, although the piece number of components to be repaired is increasing significantly. In the future, a persistent automation of the repair process chain should be achieved by developing adaptive robot assisted finishing strategies. The goal of this research is to use the automation potential for repair tasks by developing a technology that enables industrial robots to re-contour turbine blades via force controlled belt grinding.

scholarly journals A Novel Evaluation Method For Particle Deposition Measurement

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 927-934
Author(s):  
Tao Song ◽  
Chao Liu ◽  
Hengxuan Zhu ◽  
Min Zeng ◽  
Jin Wang
Keyword(s):  
Layer Thickness ◽  
Dielectric Layer ◽  
Gas Turbines ◽  
Particle Deposition ◽  
Optimization Design ◽  
Turbine Blades ◽  
Simulation Software ◽  
Circuit Board ◽  
Normal Operation ◽  
Mass Detection

Abstract Normal operation of gas turbines will be affected by deposition on turbine blades from particles mixed in fuels. This research shows that it is difficult to monitor the mass of the particles deposition on the wall surface in real time. With development of electronic technology, the antenna made of printed circuit board (PCB) has been widely used in many industrial fields. Microstrip antenna is first proposed for monitoring particles deposition to analyse the deposition law of the particles accumulated on the wall. The simulation software Computer Simulation Technology Microwave Studio (CST MWS) 2015 is used to conduct the optimization design of the PCB substrate antenna. It is found that the S11 of vivaldi antenna with arc gradient groove exhibits a monotonous increase with the increase of dielectric layer thickness, and this antenna is highly sensitive to the dielectric layer thickness. Moreover, a cold-state test is carried out by using atomized wax to simulate the deposition of pollutants. A relationship as a four number of times function is found between the capacitance and the deposited mass. These results provide an important reference for the mass detection of the particle deposition on the wall, and this method is suitable for other related engineering fields.

scholarly journals Effect of in-service burnout effect on the transonic leakage flows over cavity tip model

2021 ◽  
pp. 095765092110121
Author(s):  
Zainab J Saleh ◽  
Eldad J Avital ◽  
Theodosios Korakianitis
Keyword(s):  
Turbine Blades ◽  
High Heat ◽  
Navier Stokes ◽  
Gas Temperature ◽  
Flow Measurements ◽  
Tip Leakage ◽  
Leakage Flows ◽  
Operational Life ◽  
Flow Interactions ◽  
Blade Tip

Increasing the gas temperature at the inlet to the high pressure turbine of gas turbine engines is known as a proven method to increase the efficiency of these engines. However, this will expose the blades’ surface to very high heat load and thermal damages. In the case of the un-shrouded turbine blades, the blade tip will be exposed to a significant thermal load due to the developed leakage flows in the tip gap, this leads to in-service burnout which degrades the blade tip and shortens its operational life. This paper studies the in-service burnout effect of the transonic tip flows over a cavity tip which is a configuration commonly used to reduce the tip leakage flows. This investigation is carried out experimentally within a transonic wind tunnel and computationally using steady and unsteady Reynolds Averaged Navier Stokes approaches. Various flow measurements are established and different flow behaviour including separation bubbles, shockwave development and distinct flow interactions are captured and discussed. It is found that when the tip is exposed to the in-service burnout, leakage flow behaves in a significantly different way. In addition, the effective tip gap becomes much larger and allows higher leakage mass flow rate in comparison to the sharp-edge tip (i.e. a tip at the beginning of its operational life). The tip leakage losses are found much higher for the round-edge cavity tip (i.e. a tip exposed to burn-out effect). Experimental and computational flow visualisations, surface pressure measurements and discharge coefficient variation are given and analysed for several pressure ratios across the tip gap.

Criticality Analysis for Maintenance Purposes of Platform Supply Vessels in Remote Areas

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
A. Marhaug ◽  
A. Barabadi ◽  
E. Stagrum ◽  
K. Karlsen ◽  
A. Olsen ◽  
...  
Keyword(s):  
Failure Modes ◽  
Oil And Gas Industry ◽  
Spare Parts ◽  
Acceptable Level ◽  
Component Level ◽  
Screening Process ◽  
Essential Information ◽  
Remote Areas ◽  
Critical Components ◽  
Criticality Analysis

The oil and gas industry is pushing toward new unexplored remote areas, potentially rich in resources but with limited industry presence, infrastructure, and emergency preparedness. Maintenance support is very important and challenging in such remote areas. A platform supply vessel (PSV) is an essential part of maintenance support. Hence, the acceptable level of its availability performance is high. Identification of critical components of the PSV provides essential information for optimizing maintenance management, defining a spare parts strategy, estimating competence needs for PSV operation, and achieving the acceptable level of availability performance. Currently, there are no standards or guidelines for the criticality analysis of PSVs for maintenance purposes. In this paper, a methodology for the identification of the critical components of PSVs has been developed, based on the available standard. It is a systematic screening process. The method considers functional redundancy and the consequences of loss of function as criticality criteria at the main and subfunction levels. Furthermore, at the component level, risk tools such as failure modes, effects and criticality analysis (FMECA), and fault tree analysis (FTA) will be applied in order to identify the most critical components. Moreover, the application of the proposed approach will be illustrated by a real case study.

Mechanical Qualification of Dynamic Deep Water Power Cable

2011 ◽  
Author(s):  
Roger Slora ◽  
Stian Karlsen ◽  
Per Arne Osborg
Keyword(s):  
Water Depth ◽  
Deep Water ◽  
Failure Modes ◽  
Electrical Power ◽  
Oil And Gas Industry ◽  
Electrical Heating ◽  
Power Cable ◽  
Water Power ◽  
System Integrity ◽  
Water Depths

There is an increasing demand for subsea electrical power transmission in the oil- and gas industry. Electrical power is mainly required for subsea pumps, compressors and for direct electrical heating of pipelines. The majority of subsea processing equipment is installed at water depths less than 1000 meters. However, projects located offshore Africa, Brazil and in the Gulf of Mexico are reported to be in water depths down to 3000 meters. Hence, Nexans initiated a development programme to qualify a dynamic deep water power cable. The qualification programme was based on DNV-RP-A203. An overall project plan, consisting of feasibility study, concept selection and pre-engineering was outlined as defined in DNV-OSS-401. An armoured three-phase power cable concept assumed suspended from a semi-submersible vessel at 3000 m water depth was selected as qualification basis. As proven cable technology was selected, the overall qualification scope is classified as class 2 according to DNV-RP-A203. Presumed high conductor stress at 3000 m water depth made basis for the identified failure modes. An optimised prototype cable, with the aim of reducing the failure mode risks, was designed based on extensive testing and analyses of various test cables. Analyses confirmed that the prototype cable will withstand the extreme loads and fatigue damage during a service life of 30 years with good margins. The system integrity, consisting of prototype cable and end terminations, was verified by means of tension tests. The electrical integrity was intact after tensioning to 2040 kN, which corresponds to 13 000 m static water depth. A full scale flex test of the prototype cable verified the extreme and fatigue analyses. Hence, the prototype cable is qualified for 3000 m water depth.

Development and Fabrication of Silicon Nitride Components for Ceramic Gas Turbine

1997 ◽  
Author(s):  
Keisuke Makino ◽  
Ken-Ichi Mizuno ◽  
Toru Shimamori
Keyword(s):  
High Temperature ◽  
Silicon Nitride ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Blades ◽  
High Strength ◽  
Inlet Temperature ◽  
Turbine Inlet Temperature ◽  
Spark Plug ◽  
Power Turbine

NGK Spark Plug Co., Ltd. has been developing various silicon nitride materials, and the technology for fabricating components for ceramic gas turbines (CGT) using theses materials. We are supplying silicon nitride material components for the project to develop 300 kW class CGT for co-generation in Japan. EC-152 was developed for components that require high strength at high temperature, such as turbine blades and turbine nozzles. In order to adapt the increasing of the turbine inlet temperature (TIT) up to 1,350 °C in accordance with the project goals, we developed two silicon nitride materials with further unproved properties: ST-1 and ST-2. ST-1 has a higher strength than EC-152 and is suitable for first stage turbine blades and power turbine blades. ST-2 has higher oxidation resistance than EC-152 and is suitable for power turbine nozzles. In this paper, we report on the properties of these materials, and present the results of evaluations of these materials when they are actually used for CGT components such as first stage turbine blades and power turbine nozzles.

Aerothermal Effect of Cavity Welding Beads on a Transonic Squealer Tip

2020 ◽  
Author(s):  
Joao Vieira ◽  
John Coull ◽  
Peter Ireland ◽  
Eduardo Romero
Keyword(s):  
High Pressure ◽  
Film Cooling ◽  
Turbine Blades ◽  
Reynolds Numbers ◽  
High Pressure Turbine ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Aerodynamic Loss ◽  
Blade Tip ◽  
Mass Flow Rates

Abstract High pressure turbine blade tips are critical for gas turbine performance and are sensitive to small geometric variations. For this reason, it is increasingly important for experiments and simulations to consider real geometry features. One commonly absent detail is the presence of welding beads on the cavity of the blade tip, which are an inherent by-product of the blade manufacturing process. This paper therefore investigates how such welds affect the Nusselt number, film cooling effectiveness and aerodynamic performance. Measurements are performed on a linear cascade of high pressure turbine blades at engine realistic Mach and Reynolds numbers. Two cooled blade tip geometries were tested: a baseline squealer geometry without welding beads, and a case with representative welding beads added to the tip cavity. Combinations of two tip gaps and several coolant mass flow rates were analysed. Pressure sensitive paint was used to measure the adiabatic film cooling effectiveness on the tip, which is supplemented by heat transfer coefficient measurements obtained via infrared thermography. Drawing from all of this data, it is shown that the weld beads have a generally detrimental impact on thermal performance, but with local variations. Aerodynamic loss measured downstream of the cascade is shown to be largely insensitive to the weld beads.

Sign in / Sign up

Export Citation Format

Share Document