The New Mercedes-Benz Medium Duty Commercial Natural Gas Engine

Hoffmann, Kai; Benz, Michael; Weirich, Marko; Herrmann, Hans-Otto

doi:10.1007/s38313-014-0251-4

Cited by 9 publications

(4 citation statements)

References 3 publications

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“…In the case of stoichiometric operation, a three-way catalytic (TWC) converter can provide fairly simple exhaust gas aftertreatment with low nitrogen oxide (NO x ) emissions. 2 Throttle losses in part load and a low compression ratio due to knocking have, however, proved a drawback. This leads to lower efficiency compared with diesel engines, and only a portion of the CO 2 reduction potential of the natural gas fuel can be used.…”

Section: Introductionmentioning

confidence: 99%

Numerical and optical analysis of heterogeneous gas combustion with diesel pilot ignition in a commercial vehicle engine

Hatzipanagiotou

Marko

Koenig

et al. 2017

International Journal of Engine Research

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A new optical measurement technology and a simulation methodology for supporting the combustion system development of a high-pressure gas-diesel combustion system are presented for the first time. With this combustion system, natural gas is directly injected with high pressure into the combustion chamber near top dead center. The simulation methodology is being validated by comparison with a commercial vehicle single-cylinder metal engine and combustion imaging on a commercial vehicle optical engine with full optical access to the combustion chamber through a contoured piston window. For the optical analysis of the gas-diesel combustion system, a measurement setup for the combined two-dimensional imaging of the OH* chemiluminescence and the soot luminescence is being developed. These images allow the ignition characterization and the cyclic stability of combustion to be analyzed. With the support of the simulation methodology, the nozzle-bowl configuration can be designed with regard to optimum mixture formation and low emissions. A thermodynamic validation of the simulation results shows good agreement of the ignition timing and the following combustion phases with heat release rate data obtained from measurements. Furthermore, the end of engine soot concentrations are captured quantitatively well. A local comparison of optical images and simulation data demonstrates that the simulation is able to capture the gas ignition zones well. The combustion intensity and thus the local soot formation are slightly underpredicted in the center of the gas jets. However, the mixture formation and the overall regions of soot formation are in good agreement with the optical images.

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Section: Introductionmentioning

confidence: 99%

Numerical and optical analysis of heterogeneous gas combustion with diesel pilot ignition in a commercial vehicle engine

Hatzipanagiotou

Marko

Koenig

et al. 2017

International Journal of Engine Research

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“…This single cylinder engine has recently been used to conduct baseline investigations for the combustion development of a modern natural gas fuelled commercial vehicle engine [12] in another study. The experimental setup and the procedure used for the present study are depicted in the following.…”

Section: Measurements Of the In-cylinder Pressure Trace In A Single Cmentioning

confidence: 99%

Validation of turbulent flame speed models for methane–air-mixtures at high pressure gas engine conditions

Ratzke

Schöffler

Kuppa

et al. 2015

Combustion and Flame

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“…3 The ATST turbo was applied in Daimler's heavyduty engines of OM470, OM471, OM472, and OM473. [4][5][6][7] According to Mu¨ller et al 8 from Daimler, the turbine driven by small scroll (i.e. small scroll turbine) ran at significantly low efficiency and a low turbine reaction degree; thus achieving sufficiently high EGR drive capability.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, an ATST generally takes one wastegate connected to the large scroll to avoid over-boost pressure. 5 However, a novel ATST with a balance valve, linked to the small scroll and large scroll, effectively achieves noticeable fuel economy. 32 The balance valve design is capable of down-regulating pump loss, increasing air fuel ratio, and enhancing fuel economy at middle and high engine speed ranges with turbine efficiency improvement.…”

Section: Introductionmentioning

confidence: 99%

Effect of balance valve on exhaust pulse energy of a heavy-duty diesel engine equipped an asymmetric twin-scroll turbine

Jin

Pan

Cao

2022

Proceedings of the Institution of Mechanical Engineers, Part D:

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The exhaust pulse energy of engine is capable of driving the asymmetric twin-scroll turbine to run complicatedly in a wider flow range, which significantly causes more difficulty of an asymmetric twin-scroll turbine to match a diesel engine. In the present study, It was initially analyzed that an engine exhaust pulse energy of an asymmetric twin-scroll turbine with a balance valve. First, a pulsating flow model of asymmetric twin-scroll turbine was built to decouple the operation states of the small and large scroll turbines. Second, the experiments of asymmetric twin-scroll turbine were performed on a turbine test rig and an engine performance stand to determine the operation rules of turbine flow parameter, turbine efficiency, blade speed ratio, as well as turbine available energy. Asthe balance valve opens, the flow parameter of twin-scroll would perform more broadly around the swallow capacity curves of equal admission. Moreover, the fully-opened balance valve would make the exhaust pulse strength at the small and large scroll inlets sharply degrade by about 25% and 21%, the cycle turbine efficiency enhance by nearly 3%, the turbine available energy and BSFC degrade by about 8.15% and 2.9% at 800 rpm full load engine condition; At 1100 rpm full load engine condition, the exhaust pulse strength at the small and large scroll inlets only degraded by about 7.2% and 5.8%, the cycle turbine efficiency enhanced by about 4%, the turbine available energy and BSFC improved by about 3.7% and 2.1%. Lastly, this study delved into the distributions of the balance valve opening rate and the pulse strength at the small and large scroll inlets at full engine map.

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The New Mercedes-Benz Medium Duty Commercial Natural Gas Engine

Cited by 9 publications

References 3 publications

Numerical and optical analysis of heterogeneous gas combustion with diesel pilot ignition in a commercial vehicle engine

Numerical and optical analysis of heterogeneous gas combustion with diesel pilot ignition in a commercial vehicle engine

Validation of turbulent flame speed models for methane–air-mixtures at high pressure gas engine conditions

Effect of balance valve on exhaust pulse energy of a heavy-duty diesel engine equipped an asymmetric twin-scroll turbine

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