Thermodynamic consideration of the Miller cycle on the basis of simulation and measurements

Schutting, Eberhard; Dumböck, Ortwin; Kraxner, Thomas; Eichlseder, Helmut

doi:10.1007/978-3-658-12918-7_19

Cited by 5 publications

(2 citation statements)

References 2 publications

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“…Considering mechanical issues such as friction [14] and mass balancing [15] it may nevertheless turn out to be more convenient to use Miller cycle process in short-term series solution [16] accepting some disadvantages in peak efficiency.…”

Section: Discussionmentioning

confidence: 99%

Extended expansion linkage engine: a concept to increase the efficiency

Dumböck

Schutting

Eichlseder

2018

Automot. Engine Technol.

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In a broad-based survey, the reciprocating piston engine with extended expansion stroke was found to have the highest efficiency potential for passenger car propulsion. To confirm the predicted efficiency, three different prototype engines were built and measured on testbed. Measurements were complemented with thermodynamic simulations. Investigations focused on naturally aspirated and supercharged SI engines. It could be shown that a naturally aspirated SI engine with an expansion ratio of 2 gains an efficiency improvement of 7 percentage points compared to a conventional crank train engine. It was also found that the extended expansion has no inherent effect to combustion, emission formation and wall heat transfer. Major effort was made to assess the Miller cycle as a thermodynamic alternative to the crank train with extended expansion. Measurements and simulations revealed that Miller suffers in a way from higher wall heat and gas exchange losses cutting a substantial share of the efficiency potential of an equivalent crank train solution. Keywords Extended expansion • Atkinson cycle • Miller cycle Abbreviations atm Atmospheric AFR Air to fuel ratio BDC Bottom dead centre BP Boost pressure CA Crank angle c Compression COMP Compressor Volume ratio Ex Expansion EE Extended expansion EGBP Exhaust gas back pressure c Compression ratio

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Section: Discussionmentioning

confidence: 99%

Extended expansion linkage engine: a concept to increase the efficiency

Dumböck

Schutting

Eichlseder

2018

Automot. Engine Technol.

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“…Detailed descriptions of the RCD + method can be found in Ku¨hberger 14 and Schutting. 15 The cycles were performed at 23°C ambient temperature and without external heating or cooling of the coolant. By conditioning the system in the described manner, it was possible to start each cycle with the same initial parameters as a 'cold' cycle.…”

Section: Raw Exhaust Gas Emissions Of Different Driving Cyclesmentioning

confidence: 99%

Emission behaviour and aftertreatment of stationary and transient operated hydrogen engines

Roiser,

Christoforetti,

Schutting

et al. 2023

International Journal of Engine Research

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As society moves towards climate neutrality, hydrogen fuelled internal combustion engines (H2 ICEs) should be considered as a prime technology. These engines are valued for their robustness, superior lifetimes, manufacturing techniques and characteristics, which are already known from diesel or gasoline engines. Since an H2 ICE is run on hydrogen (H2), carbon-based emissions are only released on a very low level from the lube oil. Nitrogen oxides (NOx) emissions are de facto the only gaseous pollutant that must be processed by the exhaust aftertreatment system (EAS) of such engines. This paper provides an overview of the raw exhaust gas emission behaviour of a 2 l four-cylinder passenger car engine that is run solely on hydrogen. As already mentioned, the main challenge faced by the EAS is to reduce NOx. Thus, the inspected EAS includes a selective catalytic reduction (SCR) catalyst with ammonia (NH3) as a reductant. The species of NOx was reduced under stationary operation conditions at all of the considered engine load points at an efficiency of at least 98%. Strategies that could be applied to conduct a load change of an H2 ICE were experimentally investigated. To perform a load change under high performance conditions, H2 ICEs needed to be run on a richer air-fuel mixture than under stationary operation conditions in order to provide enough exhaust enthalpy for the turbocharger. If a richer air-fuel mixture was used, higher NOx emissions were detected, increasing the necessity of an EAS containing an SCR catalyst for H2 ICEs. A WLTC and two RDE cycles were investigated to determine their raw and tailpipe exhaust gas emissions. By applying a simple AdBlue® dosing strategy, the raw NOx exhaust gas emissions from the WLTC could be reduced from 79.9 mg/km to as low as 7.3 mg/km. Carbon-based and secondary emissions such as NH3 and nitrous oxides (N2O) were measured at levels well below 5 mg/km.

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Kurbeltriebs- und Ventiltriebs-Variabilitäten zur Effizienz- und Leistungssteigerung von Dieselmotoren

Kellermayr

Kraxner

2017

Proceedings

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Thermodynamic consideration of the Miller cycle on the basis of simulation and measurements

Cited by 5 publications

References 2 publications

Extended expansion linkage engine: a concept to increase the efficiency

Extended expansion linkage engine: a concept to increase the efficiency

Emission behaviour and aftertreatment of stationary and transient operated hydrogen engines

Kurbeltriebs- und Ventiltriebs-Variabilitäten zur Effizienz- und Leistungssteigerung von Dieselmotoren

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