Development of Thermal Barrier Coating using Low Thermal Conductivity Material for Piston

Ryoko Yamanoi･Kazuki Ogiwara･Teppei Tano (Art Metal Mfg.)･Shohei Hosoo (NT&I)･Yasushi Murakami (Shinshu University)

For thermal efficiency improvement of engine, thermal barrier coating on the piston top surface is a remarkable technology. However, implementation of the coating with following capability of combustion gas temperature and durability is still a challenge.
In this study, the results of coating design using material with porous filler to achieve unprecedent low thermal conductivity are reported.

Study of HC Trap System to Reduce HC Emissions during Engine Cold-Start

Hiroki Takeori･Koji Nemoto･Yuki Oku･Ryohei Ikutomo･Takeshi Mori (Honda R&D)･Keita Nakao･Toyohiro Usui･Ryo Mitsuhashi･Naoto Nakazawa (TOSOH)･Yuichi Matsuo (Honda R&D)

A new HC trap system for reducing emissions was developed. As a result of the development of two zeolite materials, one zeolite can be trapped at a higher temperature than conventional materials, and another zeolite that can adsorb small HC, enhancement of adsorption performance and desorption suppression has been realized. In addition, the adsorption and purification performance has been improved by optimizing the arrangement of TWC and HC traps. These factors make it possible to reduce HC emissions at engine startup by 50% compared to TWCs only.

Mechanism Validation of Random PN Emission Occurrence without Depending on Engine Control

Hiroya Okada･Yoshirou Shiina･Tomohiro Nakayama･Takafumi Tado･Natsuki Takahata･Kenta Kimoto･Masao Onoue･Kunihiko Suganuma (SUBARU)

Random PN emission without depending on engine control was confirmed. To determine the mechanism elucidation, we performed visualization and used various engine specifications tests. As a result, it revealed that there is a high possibility that the PN is derived from the oil remained on the surface of combustion chamber wall, since piston top ring end-gap cannot catch liner-oil which will be a cause of partial rich burn.

Improvement of Thermal Efficiency for K-car Engine Applying Specification Exploration with Quality Engineering Tool

Norifumi Mizushima (AIST)･Kyohei Yamaguchi (Kokushikan University)･Youichi Iiyama･Yuji Kado (JAXA)

For improving thermal efficiency of K-car engine under usual operating conditions, the authors explored the optimized engine parameters applying quality engineering tool for 0D engine cycle simulation model. In this simulation study, the potential for improving thermal efficiency was clarified by exploring various engine geometrical parameters such as bore and stroke, compression ratio, connecting rod length and intake valve timing, etc. regardless of the engine displacement standard for K-cars. The results indicated that expanding the displacement beyond 660 cm3 and increasing the expansion ratio by using Miller cycle significantly improved the thermal efficiency for K-car engines.

Hydrogen Combustion Engine Hybridization: Challenges and Solutions Towards Optimal Efficiency and Lowest Emissions

Joel Op De Beeck･Badr-Din Lahmoumi･Jezer Costa･Krzysztof Potaczek･Marcos Carvalho-Barreto･Nissrine Harbil･Toshihiko Minami･Maungu Sandra (Plastic Omnium)

In coming years, European countries will set more stringent CO₂ and NOx emission limits as seen as the EURO7 regulations.
To face those challenges, CO₂-free low emission powertrain solutions will be needed,
and the feasibility of hydrogen ICE has been studied and proven.
Next steps are to optimize energy efficiency, whilst meeting the upcoming NOx emission standards.
This study analyses the optimal sizing of hybridization, enabling to use the engine at its full potential with low electrification cost.
In parallel, the effect of hybridization on engine-out emissions is studied to Optimize tailpipe emissions to be kept at the lowest level.