リーン/リッチのλ振動による三元触媒のメタン浄化性能向上に関する研究（第2報）

津田　豊史・三浦　和也・伊藤　裕也・横尾　正太・木俣　文和（スズキ）

メタンは自動車排ガスに含まれ，その温室効果はCO₂の約25倍と高い．メタンは化学的に安定であるため三元触媒による浄化が困難であるが，例外的にリッチ/リーンとλが振動するときメタン浄化率が向上する．本研究ではλ振動を与えたときのメタン浄化率向上に，排ガス中のCO，NO，H2Oが関与していることを明らかにした．

Air Path and Exhaust Aftertreatment Optimization for Medium-Duty Hydrogen Engines

Martin Weber･Thomas Spannaus･Hubertus Ulmer･Thaddaeus Delebinski (IAV)

For reaching the climate goals to slow down the global warming, an urgent decarbonization of the transport sector must be accomplished. Since hydrogen combustion engines emit pollutants like nitrogen oxides and unburnt hydrogen, emission aftertreatment systems will have to be implemented for future emission legislations like EU VII and Tier 5.
The proposed paper will present different exhaust aftertreatment technologies with focus on the impact of especially NOx and hydrogen slip. Investigations were carried-out with a holistic model-based simulation approach, using validated GT-Suite models as well as test bench results.

尿素SCRシステムにおける加熱尿素水噴霧の特性解析

稲崎　健太朗・菊川　友太・西村　佳那子（同志社大学大学院）・松村　恵理子（同志社大学）

低温排ガス条件下の尿素SCRシステムでは，尿素が分解されないことによるNOx浄化率の低下が課題である．本研究では，尿素水噴霧の微粒化，蒸発，化学反応の促進を目的とし，尿素水の加熱制御を行った．本報では，尿素水加熱度が噴霧の微粒化特性および相変化特性に与える影響を光学撮影により解析した結果を報告する．

尿素SCRシステムにおけるN₂O生成要因の解析とシステム設計指針の提案

米山　香澄・藤井　謙治・大堀　鉄平・小澤　恒・石川　直也（いすゞ中央研究所）・阿野田　洋（いすゞ自動車）

尿素SCRシステムにおいて，NOx浄化に伴う亜酸化窒素（N2O）の副生成が課題である．本研究では，尿素SCRシステムのプラントモデルに含まれる5因子の組合せによる感度解析を実施する．N2O生成要因を解明することで，NOx浄化率向上とN2O生成抑制を両立可能な尿素SCRシステムの設計指針を提案する．

Development of GPF Based on Capillary GPF Model for Euro7 Regulation

Sungmu Choi･Jiho Cho･Sangmin Lee (Hyundai Motor)

To predict PN(Particulate Number) filteration efficiency and pressure drop of GPF, capillary models of two on-wall coated GPFs and one membrane GPF were developed. The microstructure of the GPF was taken into account by several capillaries that can represent pore size distribution and porosity in GPF.
Capillary models of on-wall coated GPF and membrane GPF were calibrated based on engine bench tests. Membrane GPF showed higher PN filtration efficiency and lower pressure drop compared to the on-wall coated GPF. Maximizing PN filteration efficiency of on-wall coated GPF based on its capillary model was investigated by removing cracks on coating layer. The effect of engine-out PN and PM(Particulate Mass) on GPF-out PN by its capillary model was investigated to meet Euro7 regulation. It was found that larger particle was more effective in reducing GPF-out PN than smaller one under the same engine-out PN conditions.

量子化学計算により排ガス浄化触媒の活性を予測する技術の開発

三浦　和也（スズキ）・草場　裕貴・三好　智也（熊本大学）・芳田　嘉志（金沢大学）・土崎　浩幸（スズキ）・町田　正人（熊本大学）

排ガス触媒上の詳細化学反応の活性化エネルギーを第一原理計算で求め，その値を化学反応速度論のCAEソフト（exothermia-suiteなど）に入力することで，触媒活性を予測する技術を開発した．CO-NO-O2反応に対するRh（111）面の浄化率曲線を予測して提案手法の妥当性を評価した．

Study on PN Characteristics by Type of Damaged DPF for Diesel Vehicles Operating in the IDLE Condition

Jaeun Yoo･Giyoung Park･Sujeong Jang･Seangwock Lee (Kookmin University)

Road traffic is one of the biggest cause of urban air pollution, and particulate matter(PM) emitted from diesel vehicles is harmful to respiratory health. In some countries, there is a trend to regulate PM emissions from diesel vehicles during periodic technical inspections. A project to attach an exhaust gas reduction device was carried out in Republic of Korea, but the Retro-fit DPF is known to be less efficient in reducing pollutants in the exhaust gas due to poor management. In this experiment, the damaged DPF was installed on the test vehicle and the PN characteristics emitted were compared and analyzed.