Ethanol effect as premixed fuel in dual-fuel CI engines: Experimental and numerical investigations

Fraioli, Valentina; Mancaruso, Ezio; Migliaccio, Marianna; Vaglieco, Bianca Maria

doi:10.1016/j.apenergy.2014.01.008

Cited by 37 publications

(15 citation statements)

References 25 publications

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“…The use of post injections is thought to have influence on both soot oxidation and soot formation processes [28,29]. Thus, the different theories suggested by the authors attribute the reduction of engine-out soot emissions to different reasons such as the extra energy for mixing introduced in the chamber by the post injection pulse [30], the high temperature in the chamber prompted by the post injection reactions [31] and the lower soot produced by the main pulse due to the lower fuel mass injected [32]. In any case, all the studies in literature conclude that the use of post injections is a very effective method to reduce engine-out soot emissions for a wide variety of engine sizes and range of operating conditions.…”

Section: In-cylinder Strategies For Soot Emissions Controlmentioning

confidence: 99%

“…Finally, it is interesting to remark that the designed geometry resulted in 5.7% reduced piston surface versus the stock piston, which will contribute to minimize the total heat transfer. The second geometry was named as "bathtub" as it follows some of the design guidelines provided in [29,30]. Using detailed CFD modeling, the cited works demonstrated that, for fixed compression ratio, the gross indicated efficiency of RCCI increases as the piston bowl radius increases and the piston bowl depth decreases.…”

Section: Description Of the Piston Bowl Geometries Studiedmentioning

confidence: 99%

“…Requires two side injectors with high number of nozzle holes (x16) of very low diameter (80 µm). The compression ratio of the engine was 16.5:1. Premixed compression ignition (PCI) [30]. The use of an impinged-spray nozzle realizes low penetration, high-dispersion and high injection rates.…”

Section: Fuel Stratification Using Direct Injectionmentioning

confidence: 99%

“…The use of these PRF as surrogate fuels to represent the combustion characteristics of diesel and gasoline, respectively, is widely used in literature [30,31,41].…”

Section: Main Submodelsmentioning

confidence: 99%

“…The reduction in the calculation domain with a cyclic boundary conditions 2 imposed at its both sides allows reducing considerably the calculation time while maintaining a high precision [30,31].…”

Section: Hypothesesmentioning

confidence: 99%

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Dual-fuel compression ignition: towards clean, highly efficient combustion

Monsalve¹

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The more and more stringent emissions regulations, together with the greater fuel economy demanded by vehicle users, impose a clear objective to researchers and engine manufacturers: look for the maximum efficiency with the minimum pollutant emissions levels.The conventional diesel combustion is a highly efficient process, but also leads to high levels of NOx and soot emissions that require using aftertreatment systems to reduce the final levels released to the environment. Since these systems incur in higher costs of acquisition and operation of the engine, the scientific community is working on developing alternative strategies to reduce the generation of these pollutants during the combustion process itself.The literature shows that the new combustion modes based on promoting low temperatures during this process, offer high efficiency and very low NOx and soot levels simultaneously. However, after years of investigation, it can be concluded that these techniques cannot be applied in the whole engine operating range due to, among others, factors like the low control of the combustion process. In recent years, it has been demonstrated that the dual-fuel combustion technique allows to overcome this limitation thanks to the additional degree of freedom provided by the capacity of modulating the fuel reactivity depending on the engine operating conditions. This characteristic, together with the near-zero NOx and soot levels obtained with this technique, has encouraged the scientific community to deeply investigate the dual-fuel combustion. In this sense, former works confirm the advantages previously described, concluding that still exist some limitations to be tackled, as well as some margin for improving the potential of this combustion concept.The general objective of the present doctoral thesis is to contribute to the understanding of the dual-fuel combustion mode, with the particular aim of exploring different ways to improve its efficiency. For this purpose, it has been experimentally evaluated different options such as the modification of the engine operating parameters, specific designs of the piston geometry or the use of alternative fuels.With the aim of answering some of the questions found in the literature, the first part of each study has been dedicated to perform a detailed analysis of the influence of each particular strategy on the dual-fuel operation at low load. Later, it has been checked the ability of each option to extend the dual-fuel operating range towards higher engine loads. It is interesting to note that the analysis of some results has been supported by CFD calculations, which have allowed to understand some local phenomena occurring during the dual-fuel combustion process, which cannot be confirmed only from the experimental point of view.Finally, taking into account the knowledge acquired during the different studies performed, the last chapter of results has been devoted to evaluate the ability of the dual-fuel concept to operate over the whole engine map, as well as to iden...

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Section: In-cylinder Strategies For Soot Emissions Controlmentioning

confidence: 99%

Section: Description Of the Piston Bowl Geometries Studiedmentioning

confidence: 99%

Section: Fuel Stratification Using Direct Injectionmentioning

confidence: 99%

“…The use of these PRF as surrogate fuels to represent the combustion characteristics of diesel and gasoline, respectively, is widely used in literature [30,31,41].…”

Section: Main Submodelsmentioning

confidence: 99%

Section: Hypothesesmentioning

confidence: 99%

See 3 more Smart Citations