Ceramic Vanes for a Model 501-K Industrial Turbine Demonstration

2000 ◽  
Author(s):  
Richard A. Wenglarz ◽  
Ken Kouns
Keyword(s):  
Second Phase ◽  
Processing Plant ◽  
Successful Operation ◽  
Barrier Coatings ◽  
Environmental Barrier Coatings ◽  
Gas Processing ◽  
Oxidation Rates ◽  
Commercial Operation ◽  
Full Power ◽  
And Performance

First-stage ceramic vanes and their metallic mounts have been designed and fabricated for retrofit into Rolls-Royce Allison Model 501-K turbines. Thermal shock tests of the AS 800 ceramic vanes were conducted using a combustor rig. The ceramic vanes and mounts were then successfully operated in a Model 501-KB5 turbine during engine proof tests for a total of 22 hr. After inspection of the ceramic vane assembly, the turbine was reassembled and shipped to an Exxon natural gas processing plant near Mobile, AL, for the first phase of a field demonstration. The Model 501-KB5 turbine experienced the rigors of commercial operation, including an emergency shutdown (unrelated to the ceramic vane assembly) and a full power water wash. No forced shutdowns associated with the ceramic vanes were experienced. Successful operation for 815 hr (793 hr at Exxon and 22 hr engine proof test) was achieved for the Model 501-KB5 turbine with first-stage ceramic vanes during which the engine sustained power and performance. Analyses of the vanes revealed ceramic oxidation rates that are excessive for industrial turbine applications. A second phase of the ceramic vane demonstration is planned to evaluate environmental barrier coatings (EBCs) to inhibit ceramic oxidation rates.

Development and Evaluation of Environmental Barrier Coatings for Si-Based Ceramics

2004 ◽  
Author(s):  
Tania Bhatia ◽  
Venkat Vedula ◽  
Harry Eaton ◽  
Ellen Sun ◽  
John Holowczak ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Silicon Nitride ◽  
Field Tests ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Barrier Coatings ◽  
Environmental Barrier Coatings ◽  
Environmental Barrier ◽  
And Performance ◽  
Combustor Liner

Environmental barrier coatings (EBCs) are being developed for silicon carbide (SiC) based composites and monolithic silicon nitride (Si3N4) to protect against the accelerated oxidation and subsequent silica volatilization in high temperature, high-pressure steam environments encountered in gas turbine engines. While EBCs for silicon carbide (EBCSiC) have been demonstrated in combustor liner applications, efforts are ongoing in the development of EBC systems for silicon nitride (EBCSiN). The challenges of adapting EBCSiC to monolithic Si3N4 are discussed in this paper. Progress in the area of EBCSiN including development and performance during field tests and tests simulating engine conditions are reviewed.

Features and Performance Data of Cooper-Bessemer Coal-Fueled Six-Cylinder LSB Engine

1992 ◽  
Vol 114 (3) ◽  
pp. 509-514 ◽  
Author(s):  
A. K. Rao ◽  
E. N. Balles ◽  
R. P. Wilson
Keyword(s):  
Preliminary Test ◽  
Injection System ◽  
Exhaust Emission ◽  
Successful Operation ◽  
Single Cylinder ◽  
System A ◽  
Full Power ◽  
Emission Control System ◽  
And Performance ◽  
Engine Components

The six-cylinder Cooper-Bessemer LSB engine has been converted to operate with one cylinder on coal-water slurry (CWS) fuel and with five cylinders operating on diesel fuel. This development followed the successful operation of the single-cylinder JS engine on CWS for over 600 hours to date. The CWS injection system was scaled up about a factor of two in fuel volume from the JS system. A new cam box drive was fabricated for the LSB single-cylinder operation. The engine was operated and full power output was achieved from the CWS cylinder. Preliminary test results indicate good operate efficiency. An exhaust emission control system is in place for the proposed operation of all the six cylinders on CWS and major engine components are on hand. These results mark a significant milestone in the progress toward commercial readiness of the coal-fueled diesel engine system.

scholarly journals Environmental Barrier Coatings Having a YSZ Top Coat

2002 ◽  
Author(s):  
Kang N. Lee
Keyword(s):  
Atmospheric Pressure ◽  
Atmospheric Pressure Plasma ◽  
Second Phase ◽  
Stabilized Zirconia ◽  
Barrier Coatings ◽  
Environmental Barrier Coatings ◽  
Environmental Barrier ◽  
Cte Mismatch ◽  
Low Modulus ◽  
Mismatch Stress

Environmental barrier coatings (EBCs) with a Si bond coat, a yttria-stabilized zirconia (YSZ) top coat, and various intermediate coats were investigated. EBCs were processed by atmospheric pressure plasma spraying. The EBC durability was determined by thermal cycling tests in water vapor at 1300°C and 1400°C, and in air at 1400°C and 1500°C. EBCs with a mullite (3Al2O3·2SiO2)+BSAS (1-xBaO·xSrO·Al2O3·2SiO2) intermediate coat were more durable than EBCs with a mullite intermediate coat, while EBCs with a mullite/BSAS duplex intermediate coat resulted in inferior durability. The improvement with a mullite+BSAS intermediate coat was attributed to enhanced compliance of the intermediate coat due to the addition of a low modulus BSAS second phase. Mullite+BSAS/YSZ and BSAS/YSZ interfaces produced a low melting (<1400 °C) reaction product, which is expected to degrade the EBC performance by increasing the thermal conductivity. EBCs with a mullite+BSAS/graded mullite+YSZ intermediate coat showed the best durability among the EBCs investigated in this study. This improvement was attributed to diffused CTE mismatch stress and improved chemical stability due to the compositionally graded mullite+YSZ layer.

scholarly journals SWIPT in mMIMO system with non-linear energy-harvesting terminals: protocol design and performance optimization

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Kui Xu ◽  
Ming Zhang ◽  
Jie Liu ◽  
Nan Sha ◽  
Wei Xie ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Performance Optimization ◽  
Power Transmission ◽  
Base Station ◽  
Second Phase ◽  
Wireless Power ◽  
Half Duplex ◽  
Non Linear ◽  
Two Phases ◽  
And Performance

Abstract In this paper, we design the simultaneous wireless information and power transfer (SWIPT) protocol for massive multi-input multi-output (mMIMO) system with non-linear energy-harvesting (EH) terminals. In this system, the base station (BS) serves a set of uplink fixed half-duplex (HD) terminals with non-linear energy harvester. Considering the non-linearity of practical energy-harvesting circuits, we adopt the realistic non-linear EH model rather than the idealistic linear EH model. The proposed SWIPT protocol can be divided into two phases. The first phase is designed for terminals EH and downlink training. A beam domain energy beamforming method is employed for the wireless power transmission. In the second phase, the BS forms the two-layer receive beamformers for the reception of signals transmitted by terminals. In order to improve the spectral efficiency (SE) of the system, the BS transmit power- and time-switching ratios are optimized. Simulation results show the superiority of the proposed beam-domain SWIPT protocol on SE performance compared with the conventional mMIMO SWIPT protocols.

Computational investigation of foreign object damage sustained by environmental barrier coatings (EBCs) and SiC/SiC ceramic-matrix composites (CMCs)

2015 ◽  
Vol 11 (2) ◽  
pp. 238-272 ◽  
Author(s):  
Mica Grujicic ◽  
Jennifer Snipes ◽  
Ramin Yavari ◽  
S. Ramaswami ◽  
Rohan Galgalikar
Keyword(s):  
Gas Turbine ◽  
Ceramic Matrix ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Foreign Object ◽  
Barrier Coatings ◽  
Content Type ◽  
Environmental Barrier Coatings ◽  
Foreign Object Damage ◽  
Environmental Barrier

Purpose – The purpose of this paper is to prevent their recession caused through chemical reaction with high-temperature water vapor, SiC-fiber/SiC-matrix ceramic-matrix composite (CMC) components used in gas-turbine engines are commonly protected with so-called environmental barrier coatings (EBCs). EBCs typically consist of three layers: a top thermal and mechanical protection coat; an intermediate layer which provides environmental protection; and a bond coat which assures good EBC/CMC adhesion. The materials used in different layers and their thicknesses are selected in such a way that the coating performance is optimized for the gas-turbine component in question. Design/methodology/approach – Gas-turbine engines, while in service, often tend to ingest various foreign objects of different sizes. Such objects, entrained within the gas flow, can be accelerated to velocities as high as 600 m/s and, on impact, cause substantial damage to the EBC and SiC/SiC CMC substrate, compromising the component integrity and service life. The problem of foreign object damage (FOD) is addressed in the present work computationally using a series of transient non-linear dynamics finite-element analyses. Before such analyses could be conducted, a major effort had to be invested toward developing, parameterizing and validating the constitutive models for all attendant materials. Findings – The computed FOD results are compared with their experimental counterparts in order to validate the numerical methodology employed. Originality/value – To the authors’ knowledge, the present work is the first reported study dealing with the computational analysis of the FOD sustained by CMCs protected with EBCs.

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