Optimization of Injectors for Improving Thermal Efficiency and Reducing Smoke in the Combustion of Liquid Synthetic Fuels and OME

Zijian Jiang･Shusuke Tanaka･Hiroya Yamamoto･Gen Shibata･Hideyuki Ogawa (Hokkaido University)

The lower heating value of OME is lower than that of GTL, which increases the injection quantity under the same load and reduces thermal efficiency. In this study, injectors for OME and GTL were selected to supply the same amount of heat within the same injection duration, with nozzle diameter and the number of nozzles as parameters. Using a constant-volume combustion chamber, the smoke generated in the spray interference area was quantified, and thermal efficiency and emission performance were evaluated through engine testing.

Influence of the oil formulation on the oil consumption mechanisms and the emission behavior of hydrogen combustion engines

Marcus Gohl･Robert Wulff･Mathias Braun (APL Automobil-Prueftechnik Landau GmbH)･Pierre Chapelot･Peter Scholl (TotalEnergies Lubrifiants SA)･Michael Guenthner･Thorsten Fuchs･Philipp Emanuel Jung (Rheinland-Pfaelzische Technische Universitaet)

Decarbonizing transport is a key goal for governments and industry, driving innovation in powertrain technologies. Hydrogen combustion engines have emerged as a promising solution for applications ranging from heavy-duty vehicles to two-wheelers. However, hydrogens unique properties pose challenges for engine lubrication, requiring tailored formulations to address pre-ignition, particulate emissions, water contamination, and wear protection. This study explores the impact of base oil types and additives on oil consumption mechanisms and particulate emissions. Results from medium-duty truck engine tests highlight key strategies to optimize lubricants and support hydrogen engine development.

The experimental study on the effect of diesel fuel composition and distillation properties on PM production

Kohei Katori･Tsutomu Hasegawa･Masahiro Seo･Ko Takahashi (Idemitsu Kosan)

In recent years, there has been a growing demand to produce the diesel fuel with the aim of expanding the use of cracked diesel fuels. Since the cracked diesel fuels have a high aromatic content which increases the amount of PM produced, it is necessary to take countermeasures such as lightening. Hence the amount of PM produced was determined by bench tests, using fuels varying aromatic hydrocarbon species and distillation characteristics, to identify the impacts on PM production quantitatively.

Alcohol Diffusive Combustion Technique as an Alternative Diesel Combustion (First Report)
-Survey of ignition assisting method and minimum condition of pilot flame-

Takayuki Fuyuto･Kenji Fukui･Yoshiyuki Mandokoro･Reiko Ueda･Kazuaki Nishikawa･Teruaki Kondo･Yoshifumi Wakisaka (Toyota Central R&D Labs.)

Alcohol fuels, methanol and ethanol, can be promising alternative fuel for diffusive combustion in heavy-duty diesel engines. In this study, we surveyed various ignition method of methanol fuel in literatures, and found that the diesel pilot ignition is the most robust ignition technique, although which cannot be recognized to be carbon neutral combustion. The minimum condition of pilot flame area and location formed by diesel pilot injection was evaluated by in-cylinder visualization. A new injection and ignition strategy for pilot spark-ignition main diffusive combustion which uses methanol as mono-fuel was proposed. This strategy is demonstrated in the next report.

Alcohol Diffusive Combustion Technique as an Alternative Diesel Combustion (Second Report)
-Methanol-monofuel pilot spark-ignition and main diffusive combustion-

Kenji Fukui･Yoshiyuki Mandokoro･Reiko Ueda･Kazuaki Nishikawa･Teruaki Kondo･Yoshifumi Wakisaka･Takayuki Fuyuto (Toyota Central R&D Labs.)

In order to develop a methanol-monofuel diffusive combustion technology, a new combustion concept composed of spark-ignited pilot spray and the main spray diffusive combustion, which was proposed in the first report was demonstrated using an optical engine. After spark-ignition of pilot spray, the pilot flame is formed and propagates in the swirl direction while it forms flame holding behind the electrode. Then, main sprays are cascadely ignited in the swirl direction. By adding pilot spray after spark ignition the pilot flame can be extended toward the nozzle, which can ignite all main sprays during injection period.

Gasoline Component Specific Study Affecting Intake Valve Deposits

Shouta Tobe (SUBARU)･Henry Du (Lubrizol Management)

The effect of intake valve deposits (IVD) has been studied during multi-port injection (MPI), but the effect of fuel blowback on the intake system has also been confirmed in direct injection (DI). The impact on IVD may be an issue when gasoline produced by different methods, such as carbon-neutral fuel (CNF), is used. Since confirming the adverse effects requires an enormous amount of man-hours, a method that simulates the engine environment to confirm these effects is attracting attention .
In this study, we utilized a "simulated deposit test device for intake valves in L2 type gasoline engines(L2-simulator) " set according to the Chinese GB standard(GB 19592-2004). to identify gasoline components that affect IVD. The results of this investigation are hereby presented.