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- Gjirja, Savo, 1945, et al.
(författare)
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Fischer- Tropsch-Synthesis Fuels as Diesel Engine Fuel-Fuel of the Future
- 2000
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The Fischer-Tropsch (F-T) catalytic conversion process can be used to synthesize diesel fuels from a variety of feed-stocks, including coal, natural gas and biomass. Synthetic diesel fuels can have very low sulfur and aromatic content, and excellent autoignition characteristics. Moreover, Fischer-Tropsch diesel fuels may also be economically competitive with regular diesel fuel if produced in large volumes.The aim of this investigation is to reveal and analyze the effects of F- T fuels on a research diesel engine performance. Previous engine laboratory tests indicate that F-T fuels are promising alternative fuels because they can be used in unmodified diesel engines, and substantial quantitative exhaust emission reductions can be reached. Also substantial qualitative reductions, e.g. reduction of the number of hazardous chemicals and reduction of the concentration of hazardous chemicals in the exhausts may be realized. Since the engine performance is close1y related to in-cylinder processes, a detailed thermodynamic analysis has been performed revealing the real thermo-chemistry history. The experimental results have shown that F-T fuels have a beneficial effect not only on the emissions levels, but also on other energetic parameters of the engine. Heat release analysis has shown that ignition delay, cylinder peak pressure, heat release gradient and indicated efficiency are affected as well.Two different mixtures of FT-fuels with variation in carbon chain branching and, to a certain extent variation in chain 1ength were tested and their results were compared with those obtained from conventional fuel (MK 1). The selected optimized F-T fuels mixture were further tested according to the 13 mode ECE R49 test cycle and were found as good competitive alternative diesel fuels.
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- Diaz, Isael, et al.
(författare)
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A New Digital Front-End for Flexible Reception in Software Defined Radio
- 2015
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Ingår i: Microprocessors and Microsystems. - : Elsevier BV. - 0141-9331. ; 39:8, s. 889-900
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Tidskriftsartikel (refereegranskat)abstract
- Future mobile terminals are expected to support an ever increasing number of Radio Access Technologies (RAT) concurrently. This imposes a challenge to terminal designers already today. Software Defined Radio (SDR) solutions are a compelling alternative to address this issue in the digital baseband, given its high flexibility and low Non-Recurring Engineering (NRE) cost. However, the challenge still remains in the Digital Front-End (DFE), where many operations are too complex or energy hungry to be implemented as software instructions. Thus, new architectures are needed to feed the SDR digital baseband while keeping complexity and energy consumption at bay. In this article the architecture of a Digital Front-End Receiver (DFE-Rx) for the next-generation mobile terminals is presented. The flexibility needed for multi-standard support is demonstrated by detecting, synchronizing and reporting carrier-frequency offset, of multiple concurrent radio standards. Moreover, the proposed architecture has been fabricated in a 65 nm CMOS low power high-VT cell technology in a die size of 5 mm2. The core module of the DFE-Rx, the synchronization engine, has been measured at 1.2 V and reports an average power consumption of 1.9 mW during Wireless Local Area Network (WLAN) reception and 1.6 mW during configuration, while running at 10 MHz.
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- Hermann, Fredrik, et al.
(författare)
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Chemical analysis of combustion products from a high-pressure gas turbine combustor rig fueled by jet A1 fuel and a Fischer-Tropsch-based fuel
- 2006
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Ingår i: Proceedings of the ASME Turbo Expo. - 0791842363 ; 1, s. 523-532
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Konferensbidrag (refereegranskat)abstract
- A comparative experimental investigation has been performed, comparing the emissions from a synthetic jet fuel and from Jet AI. In the investigation, the unburned hydrocarbons were analyzed chemically and the regulated emissions of NOX, CO and HC were measured. All combustion tests were performed under elevated pressures in a gas turbine combustor rig. A Swedish company, Oroboros AB, has developed a novel clean synthetic jet fuel, LeanJet [registered trademark] . The fuel is produced synthetically from synthesis gas by a Fischer-Tropsch process. Except for the density, the fuel conforms to the Standard Specification for Aviation Turbine Fuels. The low density is due to the lack of aromatics and polyaromatics. Organic emissions from the gas turbine combustor rig were collected by adsorption sampling and analyzed chemically. Both the fuels and the organic emissions were analyzed by gas chromatography/flame ionization (GC/FlD) complemented with gas chromatography/mass spectrometry (GC/MS). Under the operating conditions investigated, no significant differences were found for the regulated emissions, except for emission of CO from the synthetic fuel, which, at leaner conditions, was one-quarter of that measured for Jet Al. Detailed analysis of the organic compounds showed that the emissions from both fuels were dominated by fuel alkanes and a significant amount of naphthalene. It was also found that Jet Al produced a much higher amount of benzene than the synthetic fuel. Copyright
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8. |
- Hermann, Fredrik, et al.
(författare)
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Chemical analysis of combustion products from a high-pressure gas turbine combustor rig fueled by jet A1 fuel and a flscher-tropsch-based fuel
- 2006
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Ingår i: Proceedings of the ASME Turbo Expo 2006 - Power for Land, Sea, and Air. - 0791842363 - 9780791842362 - 0791837742 ; 1, s. 523-532
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Konferensbidrag (refereegranskat)abstract
- A comparative experimental investigation has been performed, comparing the emissions from a synthetic jet fuel and from Jet AI. In the investigation, the unburned hydrocarbons were analyzed chemically and the regulated emissions of NOX, CO and HC were measured. All combustion tests were performed under elevated pressures in a gas turbine combustor rig. A Swedish company, Oroboros AB, has developed a novel clean synthetic jet fuel, LeanJet®. The fuel is produced synthetically from synthesis gas by a Fischer-Tropsch process. Except for the density, the fuel conforms to the Standard Specification for Aviation Turbine Fuels. The low density is due to the lack of aromatics and polyaromatics. Organic emissions from the gas turbine combustor rig were collected by adsorption sampling and analyzed chemically. Both the fuels and the organic emissions were analyzed by gas chromatography/flame ionization (GC/FlD) complemented with gas chromatography/mass spectrometry (GC/MS). Under the operating conditions investigated, no significant differences were found for the regulated emissions, except for emission of CO from the synthetic fuel, which, at leaner conditions, was one-quarter of that measured for Jet Al. Detailed analysis of the organic compounds showed that the emissions from both fuels were dominated by fuel alkanes and a significant amount of naphthalene. It was also found that Jet Al produced a much higher amount of benzene than the synthetic fuel.
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