Study for identifying critical diameter that can stimulate particle activation of solid fuel

• Project/Area Number: 18K03993
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19020:Thermal engineering-related
• Research Institution: Aichi Institute of Technology
• Principal Investigator: MAKINO Atsushi 愛知工業大学, 工学部, 教授 (60165678)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000); Fiscal Year 2020: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: 固体粒子の燃焼 / 限界粒径 / 着火条件 / 燃焼活性化条件 / 消炎条件 / 燃焼完結条件

Outline of Final Research Achievements

Critical conditions relevant to the combustion of solid fuel particles have been examined not only experimentally but also theoretically/analytically, related to the effective utilization of energy. In experiment, use has been made of an atmospheric oxidizer flow at 1300 K or higher, in order for carbon particles to be introduced, for burning. It has been observed that only those particles bigger than 70μm can be activated to burn. In analysis, the critical particle temperature and/or diameter, at which particles are to be activated or not, have been examined. It has been found that particles can burn only in the restricted region, that only those particles bigger than 73μm are to be activated to burn in the experimental conditions described, and that particle combustion ceases to be maintained as the particle diameters are reduced to 17μm in the course of combustion.

Academic Significance and Societal Importance of the Research Achievements

固体燃料粒子の燃焼においては，粒子と酸化剤との接触面積（反応表面積）を増大させるため，燃料粒子の微細化が推奨されているが，伝熱工学的観点からすれば，粒子の表面積は熱が出入りする伝熱表面積に他ならず，その増大は熱損失の増大を引き起こし，ひいては燃焼維持すら困難にさせる可能性がある．過度の微細化は微細化費用のムダを引き起こすばかりか，粒子自体の燃焼維持をも妨げる要因であることを学術的に示すとともに，限界の粒径がいかなる要因（雰囲気温度，酸化剤濃度，圧力など）に依存しているのかを，実験・解析の両面から明らかにしている．

Research Products

• [Journal Article] Critical condition relevant to the extinction of a carbon particle in the course of combustion. (2020)
  • Author(s): Makino, A. and Sano, H.
  • Journal Title: Proc. Combust. Inst. Volume: 38 Issue: 3 Pages: 4291-4299
  • DOI: 10.1016/j.proci.2020.06.339
  • Peer Reviewed
• [Journal Article] Critical Condition for the Mass Burning Rate Constant of a Carbon Particle Activated; Comparisons with Experimental Results (2020)
  • Author(s): Makino, A.
  • Journal Title: SCIREA J. Energy Volume: 5 Pages: 32-59
  • Peer Reviewed / Open Access
• [Presentation] Critical condition relevant to the extinction of a carbon particle in the course of combustion (2021)
  • Author(s): Makino, A. and Sano, H.
  • Organizer: The 38th International Symposium on Combustion
  • Int'l Joint Research
• [Presentation] Critical condition relevant to the extinction of a carbon particle in the course of combustion. (2021)
  • Author(s): Makino, A. and Sano, H.
  • Organizer: The 38th Symposium (International) on Combustion
  • Int'l Joint Research
• [Presentation] 固体燃料の燃焼に及ぼす粒径の影響ーOxy-fuel燃焼における限界粒径ー (2020)
  • Author(s): 牧野 敦
  • Organizer: 第58回燃焼シンポジウム
• [Presentation] 燃焼する炭素粒子の消炎に関する限界粒径－Oxy-fuel 燃焼への拡張 (2020)
  • Author(s): 佐野颯飛，牧野 敦
  • Organizer: 日本機械学会東海支部第69期総会・講演会
• [Presentation] 固体燃料の燃焼に及ぼす粒径の影響－ふく射加熱時における限界条件－ (2019)
  • Author(s): 牧野 敦
  • Organizer: 第57回燃焼シンポジウム
• [Presentation] 燃焼する炭素粒子の消炎に関する限界粒径 (2019)
  • Author(s): 佐野颯飛，牧野 敦
  • Organizer: 第57回燃焼シンポジウム
• [Presentation] 固体燃料の燃焼に及ぼす粒径の影響ー質量燃焼速度定数に関する限界条件ー (2018)
  • Author(s): 牧野 敦
  • Organizer: 第56回燃焼シンポジウム