1,721,030 research outputs found
Impact of biodiesel bulk modulus on injection pressure and injection timing. The effect of residual pressure
No full textAs the demand for energy rises fossil fuel reserves are depleted daily, increasing the interest in alternative fuels. Biodiesel is one of the best candidates in this class and its use is expected to expand rapidly throughout the world. Numerous researchers have been investigating how biodiesel affects combustion, pollutant formation and exhaust aftertreatment. There is general agreement that its combustion characteristics are similar to those of standard diesel fuel, except for a shorter ignition delay, a higher ignition temperature, and greater ignition pressure and peak heat release. Engine power output is similar with both fuels. As regards emissions, reductions in particulate matter (PM) and carbon monoxide (CO) and increases in nitrogen oxides (NOx) are described with most biodiesel blends. The latter is referred to as the 'biodiesel NOx effect'. The vast majority of researchers who explored the effect of biodiesel did so in mechanical injection engines. They found that the primary mechanism by which biodiesel increases NOx emissions is by an inadvertent advance in the start of injection timing, caused by a higher modulus and viscosity. However, more recent studies show that NOx emissions also increase in biodiesel-fuelled common rail engines, and that in some cases they actually decrease in engines with mechanically controlled fuel injection systems. This cannot be explained solely by differences in compressibility and remains an open question. The present study provides a contribution to the discussion in this field by describing a new method to evaluate the injection advance in engines with mechanically controlled pumps. The experimental data show that the advances in the start of injection timing, using biodiesel rather than mineral diesel, are smaller than those calculated with standard methods and may even not occur at all, depending on injection system design. In addition, they demonstrate that, contrary to common belief, injection pressure does not always increase when using biodiesel. These data may help explain why some researchers have found similar or even reduced NOx emission also with mechanical injection systems
Graphic Method for Stirling Engine Preliminary Design
No full textProceedings of the sixth International Stirling Engine Conference and Exhibition - Eindhoven, The Netherlands, May 26-28 199
Caratterizzazione geometrica dei compressori a viti
No full textCondizionamento dell'Aria Riscaldamento e Refrigerazione, Anno 35 n.3, Marzo 199
Mathematical model for the prediction of screw compressor performance
No full textVol III, Proceedings of the XVIIIth International Congress of Refrigeration - New Challenges in Refrigeration, Montreal, August 10-17, 1991, p.1239-124
A Prototype of a Stirling Engine for Auxiliary Employements Aboard
No full textProceedings of the 7th International Conference on Stirling Cycle Machines, Tokyo, Japan, november 5-8, 199
A New Small Stirling Engine Prototype for Auxiliary Employments Aboard
No full textIECEC paper n.SC-38 - In: Proceedings of 30th Intersociety Energy Conversion Engineering Conference, Volume III, Orlando, Florida, July 30 - August 4, 199
Performance Evaluation of a Stirling Engine Prototype for Small Power Units
No full textProceedings of the 9th International Stirling Engine Conference - Pilanesburg, Republic of South Africa, 2-4 June 199
Sviluppo e Sperimentazione di un Sistema di Iniezione Diretta a Bassa Pressione per Motore a Due Tempi
No full textVolume secondo degli atti del 2° Convegno Nazionale del Piano Finalizzato Trasporti 2 -Genova, 29-31 maggio 199
Motore a 2T ad accensione comandata alimentato mediante impianto di iniezione diretta a colpo d’ariete
No full textAtti del convegno Progetto Finalizzato Trasporti 2 ”Conclusioni e prospettive future"/1999
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