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.

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.

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.

scholarly journals The Effect of Discrete Pilot Hydrogen Dopant Injection on the Lean Blowout Performance of a Model Gas Turbine Combustor

1999 ◽  
Author(s):  
Oanh Nguyen ◽  
Scott Samuelsen
Keyword(s):  
Gas Turbine ◽  
Atmospheric Pressure ◽  
Gas Turbines ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Lean Blowout ◽  
Lean Combustion ◽  
Attractive Option ◽  
Overall Performance ◽  
Model Gas Turbine Combustor

In view of increasingly stringent NOx emissions regulations on stationary gas turbines, lean combustion offers an attractive option to reduce reaction temperatures and thereby decrease NOx production. Under lean operation, however, the reaction is vulnerable to blowout. It is herein postulated that pilot hydrogen dopant injection, discretely located, can enhance the lean blowout performance without sacrificing overall performance. The present study addresses this hypothesis in a research combustor assembly, operated at atmospheric pressure, and fired on natural gas using rapid mixing injection, typical of commercial units. Five hydrogen injector scenarios are investigated. The results show that (1) pilot hydrogen dopant injection, discretely located, leads to improved lean blowout performance and (2) the location of discrete injection has a significant impact on the effectiveness of the doping strategy.

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.

Lean/Lean Staged Low NOx Combustion for Near Stoichiometric Gas Turbine Primary Zone Conditions

2001 ◽  
Author(s):  
M. C. Mkpadi ◽  
G. E. Andrews ◽  
I. Khan ◽  
M. N. Mohd Jaafar ◽  
M. Pourkashanian ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Atmospheric Pressure ◽  
Equivalence Ratio ◽  
Fuel Injection ◽  
Nox Emissions ◽  
Two Stage ◽  
Second Stage ◽  
Lean Combustion ◽  
Primary Zone ◽  
Low Nox Combustion

A two-stage lean/lean primary zone at simulated atmospheric pressure gas turbine combustion conditions was shown to give low NOx emissions at atmospheric pressure and 600K inlet temperature. All the combustion air was admitted to the first lean stage, where very lean <5ppm low NOx combustion occurred. A 40mm outlet diameter radial swirler with radial vane passage fuel injection was used in the first stage. After completion of this first stage lean combustion, second stage of fuel injection with no associated air occurred 320mm downstream of the primary swirler outlet, using 76mm radially inward wall injection. This was followed by a dump flow expansion to a 140mm diameter combustor. This provided an expansion shear layer and associated turbulence to mix the second stage fuel with the outlet products from the primary swirl combustion. The second stage fuel burned in the depleted oxygen (∼12%) from the first stage, but still remained a lean combustion zone overall. This design was intended to achieve engine power variation using the second stage fuel. The use of the second stage fuel was shown to reduce the NOx emissions by 50% compared with injecting all of the fuel into the first stage radial swirler. Emission levels of NOx at a first stage swirler equivalence ratio of 0.4 were below 5ppm and at an overall primary zone equivalence ratio of 0.8 with the two stage fuel injection, NOx emissions were about 20ppm. The second stage flame radial distribution of equivalence ratio and emissions was determined by gas analysis. The second stage NOx formation was predicted using CFD with flamelet modelling, with a flamelet strain library computed for 12% oxygen combustion. The mole fraction profile of NOx and combustion temperatures for a range of strain rates in the second stage were predicted. NOx emissions at 0.65 equivalence ratio overall was predicted to be 23ppm at 15% oxygen compared with 16ppm measured. Improved second stage fuel mixing is required to achieve lower NOx emissions and the use of wall turbulators is recommended.

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.

Sign in / Sign up

Export Citation Format

Share Document