Clarification of extinction mechanisms of premixed flames by high-concentration water mist

• Project/Area Number: 17K06202
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Thermal engineering
• Research Institution: Akita Prefectural University
• Principal Investigator: Ogami Yasuhiro 秋田県立大学, システム科学技術学部, 准教授 (00375122)
• Co-Investigator(Kenkyū-buntansha): 杉本 尚哉 秋田県立大学, システム科学技術学部, 教授 (20291784) ; 鶴田 俊 秋田県立大学, システム科学技術学部, 教授 (90197773)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000); Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000); Fiscal Year 2017: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
• Keywords: 水ミスト / 予混合火炎 / 平均粒径 / 燃焼速度 / 粒径分布 / 層流予混合火炎 / ふく射 / 熱工学 / 火災

Outline of Final Research Achievements

Effects of the mean droplet diameter of water mist on the burning velocities were investigated experimentally.
The burning velocities of water-mist-added CH4/air premixed flames were obtained by the angle method for various conditions of the water mist mass fraction. The mean droplet diameters were controlled by changing the mixture-gas flow rate. The experimental results of burning velocities were compared between each condition of the mean droplet diameter. It was found that the burning velocities with the large mean droplet diameter of water mist became faster than those for the small mean droplet diameter, and the experimental data of burning velocities had the similar trends to previous analytical results for the mono-disperse water mist.

Academic Significance and Societal Importance of the Research Achievements

水ミストの粒径の違いが予混合火炎の抑制，消炎に及ぼす影響については，単一粒径水ミストに関して解析的および数値計算的な研究がいくつかおこなわれてきた．しかしながら，解析結果を裏付ける実験結果については，十分であるとは言えない状況である．本研究では，限定的ではあるが粒径を変化させた実験を行うことができたが，これは解析解や数値計算結果を検証する上で極めて有意義なデータである．

Research Products

• [Presentation] 粒径分布がメタン/空気/水ミスト予混合火炎に及ぼす影響 (2019)
  • Author(s): 中村 聖，須知 成光，大上 泰寛
  • Organizer: 第57回燃焼シンポジウム
• [Presentation] Impact of Water Mist on Chemical Reaction of Methane/air/water-mist Premixed Flames (2017)
  • Author(s): Seiya Nakanishi, Yasuhiro Ogami, Masahiro Ito and Takashi Tsuruda
  • Organizer: 26th International Colloquium of the Dynamics of Explosion and Reactive Systems
  • Int'l Joint Research
• [Presentation] 高濃度の水ミスト添加がメタン/空気予混合火炎の化学反応機構に及ぼす影響 (2017)
  • Author(s): 中西 聖也，伊藤 雅太，大上 泰寛，鶴田 俊
  • Organizer: 平成29年度日本火災学会研究発表会
• [Presentation] ふく射熱損失がメタン/空気/水ミスト予混合火炎に及ぼす影響 (2017)
  • Author(s): 中西 聖也，中村 聖，大上 泰寛，鶴田 俊
  • Organizer: 第55回燃焼シンポジウム