Chemical Aspects of Deposition/Corrosion From Coal-Water Fuels Under Gas Turbine Conditions

1989 ◽  
Author(s):  
Richard A. Wenglarz ◽  
Ralph G. Fox
Keyword(s):  
Gas Turbine ◽  
Coating Thickness ◽  
Coal Ash ◽  
Rotor Blades ◽  
Nox Emissions ◽  
Protection Measures ◽  
Temperature Conditions ◽  
Higher Temperature ◽  
Lower Temperature

A staged, subscale turbine combustor based on a promising rich-quench-lean combustor approach to reduce NOX emissions was used to evaluate deposition, erosion, and corrosion (DEC) from coal-water fuels (CWF). This combustor was operated with three CWF at conditions of a recuperated turbine. Specimens were exposed in two test sections at temperature conditions of the first stator vanes and first rotor blades of the recuperated turbine. Resulting deposits were chemically analyzed. Deposit covered segments of specimens were placed in a furnace to extend their exposure to the potentially corrosive deposits. The deposits produced at higher temperature first stator conditions differed significantly from those produced at lower temperature first rotor conditions. The rates of formation of the higher temperature deposits were high and the deposit chemistries were similar to the coal ash chemistry. The rates of formation of the lower temperature deposits were one to two orders of magnitude less and deposit chemistries were not the same as the coal ash chemistry. Some corrosion of a CoCrAlY coating was detected after a few hours of exposure in the DEC tests. Corrosion penetration up to one-half of the coating thickness was observed after an additional 460 hr furnace exposure. Much more testing is needed to explore whether the deposition and corrosion produced by the fuels evaluated are typical of this fuel form and to assess benefits of alternate turbine protection measures.

Chemical Aspects of Deposition/Corrosion From Coal-Water Fuels Under Gas Turbine Conditions

1990 ◽  
Vol 112 (1) ◽  
pp. 1-8 ◽  
Author(s):  
R. A. Wenglarz ◽  
R. G. Fox
Keyword(s):  
Gas Turbine ◽  
Coating Thickness ◽  
Coal Ash ◽  
Rotor Blades ◽  
Nox Emissions ◽  
Protection Measures ◽  
Temperature Conditions ◽  
Lean Combustion ◽  
Higher Temperature ◽  
Lower Temperature

A staged, subscale turbine combustor based on a promising rich-quench-lean combustion approach to reduce NOx emissions was used to evaluate deposition, erosion, and corrosion (DEC) from coal-water fuels (CWF). This combustor was operated with three CWF at conditions of a recuperated turbine. Specimens were exposed in two test sections at temperature conditions of the first stator vanes and first rotor blades of the recuperated turbine. The resulting deposits were chemically analyzed. Deposit-covered segments of specimens were placed in a furnace to extend their exposure to the potentially corrosive deposits. The deposits produced at higher temperature first stator conditions differed significantly from those produced at lower temperature first rotor conditions. The rates of formation of the higher temperature deposits were high and the deposit chemistries were similar to the coal ash chemistry. The rates of formation of the lower temperature deposits were one to two orders of magnitude less and deposit chemistries were not the same as the coal ash chemistry. Some corrosion of a CoCrAlY coating was detected after a few hours of exposure in the DEC tests. Corrosion penetration up to one-half of the coating thickness was observed after an additional 460 h furnace exposure. Much more testing is needed to explore whether the deposition and corrosion produced by the fuels evaluated are typical of this fuel form and to assess benefits of alternate turbine protection measures.

A Numerical Analysis of Gas Turbine Disks Incorporating Rotating Heat Pipes

2000 ◽  
Author(s):  
Y. Cao ◽  
J. Ling ◽  
R. Rivir ◽  
C. MacArthur
Keyword(s):  
Heat Pipe ◽  
Gas Turbine ◽  
Heat Pipes ◽  
High Heat ◽  
Thermal Dissipation ◽  
High Heat Flux ◽  
Heating And Cooling ◽  
Turbine Disks ◽  
Higher Temperature ◽  
Lower Temperature

Abstract Radially rotating heat pipes have been proposed for cooling gas turbine disks working at high temperatures. A disk incorporating the heat pipe would have an enhanced thermal dissipation capacity and a much lower temperature at the disk rim and dovetail surface. In this paper, extensive numerical simulations have been made for heat-pipe-cooled disks. Thermal performances are compared for the disks with and without incorporating the heat pipe at different heating and cooling conditions. The numerical results presented in this paper indicate that radially rotating heat pipes can significantly reduce the maximum and average temperatures at the disk rim and dovetail surface under a high heat flux working condition. In general, the maximum and average temperatures at the disk rim and dovetail surface could be reduced by above 250 and 150 degrees, respectively, compared to those of the disk without the heat pipe. As a result, a disk incorporating radially rotating heat pipes could alleviate temperature-related problems and allow a gas turbine to work at a much higher temperature.

Bureau of Mines Progress in Developing the Coal-Burning Gas Turbine Power Plant

1965 ◽  
Vol 87 (2) ◽  
pp. 215-222 ◽  
Author(s):  
W. M. Nabors ◽  
D. C. Strimbeck ◽  
R. W. Cargill ◽  
J. Smith
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Coal Ash ◽  
Rotor Blades ◽  
Ash Deposition ◽  
Coal Burning ◽  
Efficient Combustion ◽  
Burning Coal ◽  
Gas Turbine Power Plant

The Bureau of Mines is developing a turbine driven by hot gases from burning coal. Primary emphasis so far has been to develop and test new blades designed to resist coal-ash erosion, the major problem confronting earlier developers of a coal-burning turbine. Improved coal preparation and feeding equipment and more efficient combustion and ash separation systems also are being developed. Overall objective of the Bureau is to build and operate a machine to demonstrate the technical feasibility of an open-cycle coal-burning gas turbine power plant. In the early phases of the Bureau turbine program, tests were conducted with a machine initially built by the Locomotive Development Committee of Bituminous Coal Research, Inc. Blade erosion had been revealed as the major problem in the LDC work, so prior to initial operations a gas turbine manufacturer was asked to review the results of the previous tests and recommend a new blade design. Several important changes were recommended, and a set of blades incorporating the new features was designed, fabricated, and installed in the turbine in 1963. The initial test of the turbine was conducted late in 1963. In 878 cumulative hr of operation the blades suffered little from erosion. The rotor blades appear capable of an additional operating period of up to 10,000 hr, and the stator blades (slightly notched at the bases on the last three rows) for at least 5000 hr. The test results indicated that with further research and development blades capable of the 50,000 to 100,000 hr regarded as minimum for commercial power plants are a definite possibility. The major difficulty in the 878-hr test was ash deposition on the blades, especially the first-stage stator blades. Means of preventing or controlling ash deposition are being sought during a second 1000-hr test of the new blades in the summer and fall of 1964. Certain modifications were made in the coal-combustion, ash-separation, and coal-feeding systems prior to this test to improve operability of the turbine plant.

Rainbow Field Test of Coatings for Hot Corrosion Protection of Gas Turbine Blades and Vanes: I — Blade Coatings

1989 ◽  
Author(s):  
Mark Van Roode ◽  
Jose Aurrecoechea
Keyword(s):  
Gas Turbine ◽  
Field Test ◽  
Coating Thickness ◽  
Hot Corrosion ◽  
Turbine Blades ◽  
Rotor Blades ◽  
Lower Grade ◽  
Corrosion Morphology ◽  
Metallographic Examination ◽  
Gas Turbine Blades

A rainbow field test sponsored by the Electric Power Research Institute (EPRI) under contract RP2465-1 was performed to evaluate the comparative hot corrosion resistance of commercially available coatings for gas turbine blades and vanes. The 10,307-hr field test was carried out on a Solar Turbines Incorporated Centaur T-4000 gas turbine operating on a lower grade liquid fuel at the Favianca site of the Owens-Illinois, Inc. glass manufacturing facility in Valera, Venezuela. This paper reviews the results of an evaluation of the performance of three modified aluminides, three MCrAlY overlays, and one duplex NiCoCrAlY/ZrO2-2OY2O3 overlay applied as coatings to the first-stage MAR-M421 and IN-738LC rotor blades, Visual and metallographic examination and remnant coating thickness measurements established that the MCrAlY overlay coatings were generally more effective than a Cr-aluminide and two Pt-aluminides protecting the first-stage blades. Individual differences between the various coatings were established. A remnant coating thickness index (RCTI) was defined to express coating survival and protectiveness quantitatively. The results of blade airfoil temperature estimates were correlated with the hot corrosion morphology.

Crystalline Phases and Particle Characteristics of the Combustion-Synthesized TiO2 Nanoparticles

2007 ◽  
Vol 544-545 ◽  
pp. 39-42 ◽  
Author(s):  
Gyo Woo Lee ◽  
Shang Min Choi
Keyword(s):  
Tio2 Nanoparticles ◽  
Hydrogen Diffusion ◽  
Anatase Phase ◽  
Flame Temperature ◽  
Crystalline Phases ◽  
Crystalline Structures ◽  
Temperature Conditions ◽  
Particle Characteristics ◽  
Higher Temperature ◽  
Lower Temperature

TiO2 nanoparticles were synthesized with using N2-diluted and O2-enriched coflow hydrogen diffusion flames. We investigated the effects of the flame temperature on the crystalline phases and particle characteristics of the TiO2 nanoparticles that were formed. For the higher temperature conditions, the maximum centerline temperatures that were measured were greater than approximately 1,600K, and TiO2 nanoparticles, which had spherical shapes with diameters of approximately 60nm, were synthesized. For the lower temperature conditions, the maximum centerline temperatures that were measured were less than approximately 1,600K, and the diameters of the nanoparticles that were formed had unclear boundaries that ranged from 35 to 50nm. From the XRD analyses, it was believed that the crystalline structures of the nanoparticles that were formed were divided into two types. For the higher temperature cases, the fractions of the TiO2 nanoparticles that were synthesized, which had anatase-phase crystalline structures, increased with the increase of the flame temperatures. On the contrary, for the lower temperature cases, the fraction of anatase-phase nanoparticles increased with the decrease of the flame temperatures.

scholarly journals Sprouting of Sorghum (Sorghum bicolor [L.] Moench): Effect of Drying Treatment on Protein and Starch Features

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 407 ◽  
Author(s):  
Mia Marchini ◽  
Alessandra Marti ◽  
Claudia Folli ◽  
Barbara Prandi ◽  
Tommaso Ganino ◽  
...  
Keyword(s):  
Food Production ◽  
Cost Effective ◽  
High Exposure ◽  
Effective Technology ◽  
Drying Treatment ◽  
Higher Temperature ◽  
Lower Temperature ◽  
The One ◽  
Drying Conditions ◽  
Sorghum Bicolor L

The nutritional and physicochemical properties of sorghum proteins and starch make the use of this cereal for food production challenging. Sprouting is a cost-effective technology to improve the nutritional and functional profile of grains. Two drying treatments were used after sorghum sprouting to investigate whether the drying phase could improve the protein and starch functionalities. Results showed that the drying treatment at lower temperature/longer time (40 °C for 12 h) extended the enzymatic activity that started during sprouting compared to the one performed at higher temperature/shorter time (50 °C for 6 h). An increased protein hydrolysis and water- and oil-holding capacity were found in the flour obtained by the former treatment. Higher protein matrix hydrolysis caused high exposure of starch to enzymes, thus increasing its digestibility, while worsening the technological functionality. Overall, modulating drying conditions could represent a further way, in addition to sprouting, to improve sorghum flour’s nutritional profile.

MICROSTRUCTURAL EVOLUTION OF Al-Cu-Mg-Ag ALLOY WITH TRACE Zr ADDITION DURING TWO-STEP HOMOGENIZATION

2009 ◽  
Vol 23 (06n07) ◽  
pp. 855-862 ◽  
Author(s):  
FEIYUE MA ◽  
ZHIYI LIU
Keyword(s):  
Melting Point ◽  
Grain Boundaries ◽  
Microstructural Evolution ◽  
Cast Alloy ◽  
Scanning Calorimetry ◽  
Zr Addition ◽  
Homogenization Time ◽  
The Matrix ◽  
Higher Temperature ◽  
Lower Temperature

The microstructural evolution in an Al - Cu - Mg - Ag alloy with trace Zr addition during homogenization treatment was characterized by Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray Spectroscopy (EDS). It was shown that the low-melting-point phase segregating toward grain boundaries is Al 2 Cu , with a melting point of 523.52°C. A two-step homogenization process was employed to optimize the microstructure of the as-cast alloy, during which the alloy was first homogenized at a lower temperature, then at a higher temperature. After homogenized at 420°C for 6 h, Al 3 Zr particles were finely formed in the matrix. After that, when the alloy was homogenized at an elevated temperature for a longer time, i.e., 515°C for 24 h, most of the precipates at the grain boundaries were removed. Furthermore, the dispersive Al 3 Zr precipitates were retained, without coarsening greatly in the final homogenization step. A kinetics model is employed to predict the optimal homogenization time at a given temperature theoretically, and it confirms the result in present study, which is 420°C/6h+515°C/24h.

Field Conversion of a Low-Firing Frame 7B Gas Turbine Power Plant to Ultra-Low Emission Combustion

2015 ◽  
Author(s):  
Nicolas Demougeot ◽  
Jeffrey A. Benoit
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Energy Demand ◽  
Water Injection ◽  
Cost Benefit ◽  
High Energy ◽  
Nox Emissions ◽  
Environmental Controls ◽  
Low Emission ◽  
Technical Discussion

The search for power plant sustainability options continues as regulating agencies exert more stringent industrial gas turbine emission requirements on operators. Purchasing power for resale, de-commissioning current capabilities altogether and repowering by replacing or converting existing equipment to comply with emissions standards are economic-driven options contemplated by many mature gas turbine operators. NRG’s Gilbert power plant based in Milford, NJ began commercial operation in 1974 and is fitted with four (4) natural gas fired GE’s 7B gas turbine generators with two each exhausting to HRSG’s feeding one (1) steam turbine generator. The gas turbine units, originally configured with diffusion flame combustion systems with water injection, were each emitting 35 ppm NOx with the New Jersey High Energy Demand Day (HEED) regulatory mandate to reduce NOx emissions to sub 10 ppm by May 1st, 2015. Studies were conducted by the operator to evaluate the economic viability & installation of environmental controls to reduce NOx emissions. It was determined that installation of post-combustion environmental controls at the facility was both cost prohibitive and technically challenging, and would require a fundamental reconfiguration of the facility. Based on this economic analysis, the ultra-low emission combustion system conversion package was selected as the best cost-benefit solution. This technical paper will focus on the ultra low emissions technology and key features employed to achieve these low emissions, a description of the design challenges and solution to those, a summary of the customer considerations in down selecting options and an overview of the conversion scope. Finally, a technical discussion of the low emissions operational flexibility will be provided including performance results of the converted units.

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