Low Environmental Impact Combustion Method for Marine Diesel Engine Using Two Stage Combustion

• Project/Area Number: 16K06914
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Naval and maritime engineering
• Research Institution: Tokai University
• Principal Investigator: AZETSU AKIHIKO 東海大学, 工学部, 教授 (80184175)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000); Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2017: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2016: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
• Keywords: 舶用機関・燃料 / ディーゼル燃焼 / 噴霧燃焼 / 舶用機関 / すす / 空気過剰率 / 火炎温度 / 低環境負荷

Outline of Final Research Achievements

In order to realize two stage clean diesel combustion utilizing high temperature and low oxygen concentration ambient produced by HCCI combustion, this study was aimed to obtain the fundamental data experimentally. The experiments were mainly conducted to measure the soot distributions in the spray flame by using the two color method. It is confirmed that the soot distribution in flame can be subdivided into two regions, i.e., the head vortex region and the cone shaped flame region. The soot formation and oxidation in the cone shaped flame region can be treated as quasi-steady, i.e., those of steady jet flame. 1D integrated KL factor distribution and the estimated excess air ratio will be very useful tools for the study of soot formation and oxidation inside the spray flame.

Academic Significance and Societal Importance of the Research Achievements

ディーゼル燃焼の基本形態である非定常噴霧燃焼において，火炎の先端到達距離と火炎内のすす分布最大位置を，準定常理論による推定空気過剰率で統一的に予測できる可能性が得られたことは，学術的・技術的に大きな成果と考えている．隣接火炎との衝突あるいは壁面との衝突を，すす分布最大位置以降に配置することが，燃焼の悪化，すす排出の低減に重要であることを本研究の中の小型容器を用いた実験で明らかにしているが，その位置を高温低酸素場でも予測できれば2段階燃焼法の燃焼室設計に有用な指標になりうるものと考えている．

Research Products

• [Presentation] A study on soot formation and oxidation characteristics of diesel jet flame and the dominant factor affecting the length of diesel jet flame (2019)
  • Author(s): Akihiko AZETSU and Tatsuya OCHIAI
  • Organizer: 29th CIMAC World Congress 2019 in Vancouver
  • Int'l Joint Research
• [Presentation] 雰囲気酸素濃度と燃料噴射期間が小型燃焼容器中の噴霧火炎におよぼす影響 (2018)
  • Author(s): 斎藤 湧太，畔津 昭彦
  • Organizer: 第29回内燃機関シンポジウム
• [Presentation] A Visualization Study of Soot Production and Oxidation Characteristics under Diesel Engine like Conditions (2017)
  • Author(s): Huynh Thanh Cong, Takahiro Kashima, Daisuke Komasaki, Yuta Saito, Akihiko Azetsu
  • Organizer: Small Engine Technology Conference 2017 (SETC 2017), Jakarta, Indonesia
  • Int'l Joint Research
• [Presentation] Effect of Fuel Injection Duration and Ambient Condition on Combustion Characteristics and Soot Formation in Diesel Spray (2017)
  • Author(s): Tatsuya Ochiai, Yuho Nishiyama, Akihiko Azetsu, Takahiro Sako
  • Organizer: International Symposium on Marine Engineering (ISME) 2017, Tokyo
  • Int'l Joint Research
• [Presentation] 雰囲気酸素濃度と雰囲気密度が小型定容燃焼容器中の噴霧火炎に与える影響 (2017)
  • Author(s): 齋藤湧太，鹿島隆寛，駒崎大将，畔津昭彦
  • Organizer: 日本機械学会2017年度年次大会
• [Presentation] 燃料噴射圧力と雰囲気条件が小型定容燃焼容器中の噴霧火炎に与える影響 (2017)
  • Author(s): 齋藤湧太，畔津昭彦
  • Organizer: 第28回内燃機関シンポジウム