Increase of passenger car engine efficiency with low engine-out emissions using hydrogen–natural gas mixtures: A thermodynamic analysis

Dimopoulos, P.; Rechsteiner, Carl E.; Soltic, Patrik; Laemmle, C.; Boulouchos, Konstantinos

doi:10.1016/j.ijhydene.2006.12.026

Cited by 80 publications

(29 citation statements)

References 12 publications

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“…[38], as the equivalence ratio is increased approaching stoichiometry, the combustion efficiency is increased as well. In other words, as the combustion duration decreases and the process approaches the "ideal" constant volume combustion close to TDC, the combustion efficiency increases as also reported in [12].…”

Section: Investigation Of Combustion Efficiencysupporting

confidence: 62%

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A combined experimental and numerical study of thermal processes, performance and nitric oxide emissions in a hydrogen-fueled spark-ignition engine

Rakopoulos

Kosmadakis

Demuynck

et al. 2011

International Journal of Hydrogen Energy

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A COMBINED EXPERIMENTAL AND NUMERICAL STUDY OF THERMAL PROCESSES, PERFORMANCE AND NITRIC OXIDE EMISSIONS IN A HYDROGEN-FUELED SPARK-IGNITION ENGINE ABSTRACTThis work concerns the study of a spark-ignition engine fueled with hydrogen, using both measured and numerical data at various conditions, focusing on the combustion efficiency, the heat transfer phenomena and heat loss to the cylinder walls, the performance, as well as the nitric oxide (NO) emissions formed, when the fuel/air and compression ratio are varied. For the investigation of the heat transfer mechanism, the local wall temperatures and heat flux rates were measured at three locations of the cylinder liner in a CFR engine. These fluxes can provide a reliable estimation of the total heat loss through the cylinder walls and of the hydrogen flame arrival at specific locations. Together with the experimental analysis, the numerical results obtained from a validated in-house CFD code were utilized for gaining a more complete view of the heat transfer mechanism and the hydrogen combustion efficiency for the various cases examined. The performance of the CFR engine is then identified, since the calculated cylinder pressures are compared with the measured ones, from which performance and heat release rates are calculated and discussed. Further, NO emission studies have been accomplished, with the calculated results not only being compared with the measured exhaust NO ones, but also further processed for conducting an in-depth investigation of the dependence of NO production on the spatial distribution of in-cylinder gas temperature. It is revealed that for lower fuel/air ratio the burned gas temperature is held at low level and the heat loss ratio is quite low. As the load increases and stoichiometric mixtures are used, the wall and in-cylinder gas temperatures increase substantially, together with the heat loss and the NO emissions, owing to the high hydrogen combustion velocity and the consequent high rate of temperature rise. The combustion efficiency is slightly increased, but the indicated efficiency is decreased due to higher heat loss.Keywords: hydrogen; spark-ignition engine; combustion efficiency; heat transfer; NO emissions.

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Section: Investigation Of Combustion Efficiencysupporting

confidence: 62%

“…Apart from the experimental investigations of hydrogen-fueled spark-ignition engines, numerical tools are also developed [7,[10][11][12][13] in order to constitute an additional weapon in the detailed investigation of the various processes on those kind of engines.…”

Section: Introductionmentioning

confidence: 99%

A combined experimental and numerical study of thermal processes, performance and nitric oxide emissions in a hydrogen-fueled spark-ignition engine

Rakopoulos

Kosmadakis

Demuynck

et al. 2011

International Journal of Hydrogen Energy

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“…Apart from these experimental studies, there exist many simulation works focusing mainly on the engine performance parameters (Aliramezani, et al 2013) and to some extent to the nitric oxide (NO) emissions, using the thermal NO production path (Dimopoulos et al 2007), widely known as the "three-equation Zeldovich mechanism".…”

Section: Introductionmentioning

confidence: 99%

Spark-Ignition Engine Fueled with Methane-Hydrogen Blends

Kosmadakis

Moreno

Arroyo

et al. 2016

Energy, Transportation and Global Warming

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“…Apart from these experimental investigations, numerical tools are also developed [8,[13][14][15][16], which can further assist in the understanding of the various processes taking place in those engines. Especially, the results obtained from computational fluid dynamics (CFD) codes [8,16], which describe in a more fundamental way the in-cylinder processes [17,18], can identify at a local level the coupling of the relevant transport phenomena.…”

Section: Introductionmentioning

confidence: 99%

CFD modeling and experimental study of combustion and nitric oxide emissions in hydrogen-fueled spark-ignition engine operating in a very wide range of EGR rates

Kosmadakis

Rakopoulos

Demuynck

et al. 2012

International Journal of Hydrogen Energy

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CFD modeling and experimental study of combustion and nitric oxide emissions in hydrogenfueled spark-ignition engine operating in a very wide range of EGR rates To refer to or to cite this work, please use the citation to the published version:Kosmadakis, G.D., Rakopoulos, C.D., Demuynck, J., De Paepe, M. & Verhelst, S. (2012). CFD modeling and experimental study of combustion and nitric oxide emissions in hydrogen-fueled spark-ignition engine operating in a very wide range of EGR rates. INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, 37(14) ABSTRACTIn the current work, the variation of EGR rates is investigated in a hydrogen-fueled, sparkignition engine. This technique is followed in order to control the engine load and decrease the exhaust nitrogen oxides emissions. The external EGR is varied in the very wide range of 12% up to 47% (by mass), where in each test case the in-cylinder mixture is stoichiometric, diluted with the appropriate EGR rate. The operation of this engine is explored using measured data with the aid of a validated CFD code. Moreover, a new residual gas term existing in the expression of the hydrogen laminar flame speed, which has been derived from a one-dimensional chemical kinetics code, is tested in a real application for appraising its capabilities. The investigation conducted provides insight on the performance and indicated efficiency of the engine, the combustion processes, and the emissions of nitrogen oxides. More precisely, an experimental study has been deployed with the aim to identify the characteristics of such a technique, using very high EGR rates, focusing on the combustion phenomena. At the same time, the CFD results are compared with the corresponding measured ones, in order to evaluate the CFD code under such non-conventional operating conditions and to test a recent expression for the residual gas term included in the hydrogen laminar flame speed expression. It is revealed that the combustion takes place in few degrees of crank angle, especially at high engine loads (low EGR rates), whereas the exhaust nitrogen oxides emissions are significantly decreased in comparison to the use of lean mixtures for controlling the engine load. Additionally, the recent expression of the residual gas term, which has been tested and incorporated in the CFD code, seems to be adequate for the calculation of combustion phenomena in highly diluted, with EGR, hydrogen-fueled spark-ignition engines, as for every EGR rate tested (even for the higher ones) the computational results are compared in good terms with the measured data.

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Increase of passenger car engine efficiency with low engine-out emissions using hydrogen–natural gas mixtures: A thermodynamic analysis

Cited by 80 publications

References 12 publications

A combined experimental and numerical study of thermal processes, performance and nitric oxide emissions in a hydrogen-fueled spark-ignition engine

A combined experimental and numerical study of thermal processes, performance and nitric oxide emissions in a hydrogen-fueled spark-ignition engine

Spark-Ignition Engine Fueled with Methane-Hydrogen Blends

CFD modeling and experimental study of combustion and nitric oxide emissions in hydrogen-fueled spark-ignition engine operating in a very wide range of EGR rates

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