A European Regulatory Perspective towards a Euro 7 Proposal

Samaras, Zissis; Kontses, Anastasios; Dimaratos, Athanasios; Kontses, Dimitrios; Balazs, Andreas; Hausberger, Stefan; Ntziachristos, Leónidas; Andersson, Jon; Ligterink, N.E.; Aakko-Saksa, Päivi; Dilara, Panagiota

doi:10.4271/2022-37-0032

Cited by 38 publications

(18 citation statements)

References 21 publications

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“…The downstream emissions were measured at 10 ppm NH 3 slip to maximize the NO x conversion rates and to limit the NH 3 emissions, since these will be restricted by the planned Euro 7 exhaust gas emission standard. 12 Unburned hydrogen was detected in the exhaust gases of H 2 ICEs due to the incomplete combustion of the air-fuel mixture. The hydrogen is oxidized by an OC, as described in section 3.1.…”

Section: Catalysts To Reduce Raw Emissions In H 2 Ices Under Steady-s...mentioning

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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Section: Catalysts To Reduce Raw Emissions In H 2 Ices Under Steady-s...mentioning

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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“…The aim to achieve higher indicated efficiencies and lower pollutant emissions with internal combustion engines is driven by current and especially future legislations [1]. Incylinder thermal coatings offer the possibility to reduce the heat losses of the engine towards the combustion chamber walls by increased surface temperatures during the combustion, see Figure 1 [2].…”

Section: Introductionmentioning

confidence: 99%

Influence of Yttria-Stabilized Zirconium Oxide Thermal Swing Coating on the Flame-Wall Interaction in Spark Ignition Engines

Fischer

Nolte

et al. 2023

Energies

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Future vehicle powertrain systems with internal combustion engines must achieve higher efficiencies and further reduced pollutant emissions. This will require the application of new advanced technologies. Against this background, this paper presents a holistic approach to reduce temporally the wall heat losses, and hydrocarbon and carbon monoxide emissions with thermal coatings on the combustion chamber walls. For this purpose, an yttria-stabilized zirconia (YSZ) coating is applied and evaluated by different methods. The thin layer in combination with the low thermal effusivity of the material allows the wall temperature to follow the gas temperature and perform a so-called thermal swing. The interaction between an uncoated and a YSZ-coated wall with the flame front as well as partially burned gas was investigated. First, in terms of the coating’s potential to reduce the flame quenching distance using an optical method in a constant volume combustion chamber. Second, regarding its influence on the near-wall gas composition, which was analyzed with in-situ diffuse reflectance infrared Fourier transform spectroscopy measurements and a fast gas sampling technique on a single-cylinder engine. From this, it could be derived that the quenching distance can be reduced by 10% at ambient conditions and by 5% at an elevated temperature of 200 °C by using the coating. These findings also support the results that have been obtained by the near-wall gas composition measurements, where a reduced total hydrocarbon emission was found with the applied coating.

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“…12 Therefore, the achievement of the light-off temperatures is challenging without additional measures. 13 One approach to reduce THC raw emissions is to apply coatings to the combustion chamber walls, 14 which allow a reduction of the quenching distance 15 or a post and or pre-oxidation of unburned hydrocarbons. 16 To understand the effects of such coatings the gas composition near the combustion chamber walls must be analyzed.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the near-wall gas composition in SI-engines using fast gas sampling

Fischer

Lehrheuer

Pischinger

2023

International Journal of Engine Research

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Future internal combustion engines using novel fuels and combustion systems have the potential to achieve ultra-high efficiency and lowest pollutant emissions to comply with future regulatory requirements. Realizing indicated efficiencies over 50% with ultra-lean low temperature combustion face new challenges. To meet this goal, hydrocarbon (HC) and carbon monoxide (CO) emissions need to be reduced significantly further. To do this, knowledge must be gained about how the operation regime of the engine affects the HC and CO emissions. Since these emissions partly originate from areas where flame quenching occurs, an investigation of the gases near the wall is of interest. To this end a fast gas sampling method is being developed to extract and analyze the gas from the combustion chamber. The used fast gas sampling valve from Kistler enables sampling durations of less than 1 ms. Fourier-transform-infrared spectroscopy and a fast mass spectroscopy allow the determination of the sample composition. The valve is positioned inside the cylinder head of a single cylinder engine between intake and exhaust valves. In order to assess the effects of engine operating conditions on the formation of HC and CO at the cylinder walls, the measurement uncertainty of the setup must be evaluated. Since the combustion process is subject to cyclic variations, the evaluation of only a few individual measurements is not meaningful. Therefore, mean values are determined from the evaluation of several measurements not performed consecutively. By examining the mean and standard deviation of these measurements for each species, one can determine a measurement error. In comparison, lean operation with RON95E10 fuel at an IMEP = 12 bar and an engine speed of n = 2000 1/min shows a significant reduction in intermediate hydrocarbon species such as acetylene and a significant increase in fuel species such as ethanol compared to stoichiometric operation.

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A European Regulatory Perspective towards a Euro 7 Proposal

Cited by 38 publications

References 21 publications

Emission behaviour and aftertreatment of stationary and transient operated hydrogen engines

Emission behaviour and aftertreatment of stationary and transient operated hydrogen engines

Influence of Yttria-Stabilized Zirconium Oxide Thermal Swing Coating on the Flame-Wall Interaction in Spark Ignition Engines

Evaluation of the near-wall gas composition in SI-engines using fast gas sampling

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