| 61. |
- Cao, Z., et al.
(författare)
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Comparison study of the development of ethanol fuels in China
- 2010
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Ingår i: 6th Advanced Forum on Transportation of China (AFTC 2010). - : IET. - 9781849193160 ; , s. 150-154
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Konferensbidrag (refereegranskat)abstract
- Based on the analysis of the producing principles of ethanol fuels for the vehicles and their development in the world,in the article the ethanol fuels is compared with conventional fuels in eight indicators covering economic, environment and producing technology by AHP model. The main objective of this research work is to study the difficulties and arising obstacles of promoting the ethanol fuel in Chinese market based on the calculation results, and finally propose appropriate solutions and new ideas to ease the energy crisis and traffic pollutions in China.
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| 62. |
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| 63. |
- Cardozo Rocabado, Evelyn, et al.
(författare)
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Combustion of agricultural residues : An experimental study for small-scale applications
- 2014
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Ingår i: Fuel. - : Elsevier. - 0016-2361 .- 1873-7153. ; 115, s. 778-787
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Tidskriftsartikel (refereegranskat)abstract
- Energy services could be greatly improved by using of residues from local food industries in small-scale combustion units. Wood pellets are a reliant and proven fuel to be used in small-scale combustion units. However, these units should preferably be able to use different types of biomass depending what it is locally available. Therefore, studies have been focused on exploring the suitability of using agricultural residues for small-scale heat and power generation using direct combustion. This study targets to compare the combustion of different agricultural residues in a single unit designed for wood pellets. The different biomass fuels used are circle divide 6 mm and circle divide 8 mmwood pellets, circle divide 6 mmbagasse pellets, circle divide 6 mmsunflower husk (SFH) pellets and Brazil nut (BN) shells. The results reveal a decrease in the fuel power input, higher oxygen levels in the flue gases and shorter cycles for ash removal when using the agricultural residues. The excess air ratio was calculated based on a mass balance and compared with a standard equation showing a good agreement. CO and NO emission levels as well as the relative conversion of fuel-C to CO were higher for the BN shells and SFH pellets in comparison to the other biomass types. SO2 emission was estimated based on the analysis of unburned sulfur in ash and mass balances; the higher estimated levels corresponded to the BN shells and SFH pellets. All the biomass sorts presented over 95% relative conversion of fuel-C to CO2. Wood pellets and BN shells presented the highest amount of unburned carbon in ash relative to the fuel-C. The relative conversion of fuel-N to NO and fuel-S to SO2 were higher for wood pellets. Bagasse pellets showed similar emission levels and relative conversion efficiency to wood pellets.
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| 64. |
- Cardozo Rocabado, Evelyn, et al.
(författare)
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Comparison of the thermal power availability of different agricultural residues using a residential boiler
- 2016
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Ingår i: BIOMASS CONVERSION AND BIOREFINERY. - : Springer. - 2190-6815 .- 2190-6823. ; 6:4, s. 435-447
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Tidskriftsartikel (refereegranskat)abstract
- This study presents a comparison of combustion performance, losses, and efficiency at steady-state and transient conditions for different biomass types in a residential boiler. The types of biomass used were 6 and 8 mm wood pellets, 6 mm sugarcane bagasse pellets, 6 mm sunflower husk pellets, and Brazil nut shells. The comparison in the development of the temperature in the combustion chamber during the start-up revealed that the 6 mm wood pellets ignite and propagate faster than the rest of the biomass fuels due to their smaller size compared with 8 mm wood pellets and lower ash content compared with the rest of the biomass sorts. Thermal power output and efficiencies under steady-state and transient conditions were calculated by the direct method, i.e., by measuring the heat recovery by the water boiler, and the indirect method, i.e., by measuring the heat losses. By using the indirect method, the availability of the flue gas thermal power during the start-up was seen more in detail than when the other method was applied. When comparing both methods as tools for boiler efficiency evaluation for different fuel types, the discrepancy of the resulting efficiencies between is larger when there are higher amounts of chemical losses in the boiler. Therefore, this method shows good agreement also for bagasse pellets but is, without modification, proposed not to be valid for fuels emitting higher amount of carbon monoxide (CO). Boiler efficiencies reached class 3 boilers according to EN 303-5 (> 74.8 %) for all biomass sorts.
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| 65. |
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| 66. |
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| 67. |
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| 68. |
- Chernysheva, Olga V., et al.
(författare)
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Influence of a vibration amplitude distribution on the aerodynamic stability of a low-pressure turbine sectored vane
- 2006
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Ingår i: Unsteady Aerodynamics, Aeroacoustics and Aeroelasticity of Turbomachines. - Dordrecht : Kluwer Academic Publishers. - 1402042671 ; , s. 17-29
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Konferensbidrag (refereegranskat)abstract
- A parametrical analysis summarizing the effect of the reduced frequency and sector mode shape is carried out for a low-pressure sectored vane cascade for different vibration amplitude distributions between the airfoils in sector as well as the numbers of the airfoils in sector. Critical reduced frequency maps are provided for torsion- and bending-dominated sector mode shapes. Despite the different absolute values of the average aerodynamic work between four-, five- and six-airfoil sectors a high risk for instability still exists in the neighborhood of realistic reduced frequencies of modern low-pressure turbine. Based on the cases studied it is observed that a sectored vane mode shape with the edge airfoils in the sector dominant provides the most unstable critical reduced frequency map.
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| 69. |
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| 70. |
- Dahlqvist, Johan, 1987-, et al.
(författare)
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TEST TURBINE INSTRUMENTATION FOR CAVITY PURGE INVESTIGATIONS
- 2014
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Ingår i: The XXII Symposium on Measuring Techniques in Turbomachinery, Lyon, 4-5 September 2014.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The upstream wheelspace of the KTH Test Turbine has been instrumented with the aim of investigating cavity flow phenomena, as well as cavity-main annulus interaction. Measurements include static pressure, unsteady pressure and temperature.The stage used is of high pressure steam turbine design. The trials include investigating the design point and also a high pressure, high speed operating point, assimilating gas turbine operation. At each point, varying amounts of purge flow are superposed and the influences on the measurements studied.Initial results show considerable dependence of both operating
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