| Project/Area Number |
18K03967
|
|---|
| 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 | University of Tsukuba |
|---|
Principal Investigator |
|
|---|
| Project Period (FY) |
2018-04-01 – 2021-03-31
|
| Project Status |
Completed (Fiscal Year 2020)
|
| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2020: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2018: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
|
|---|
| Keywords | 超希薄燃焼 / 予混合燃焼 / 旋回火炎 / 再循環領域 / 炭化水素燃料 / 拡散熱的不均衡 / アサガオ状火炎 / 正ヘプタン / 希薄燃焼 / 正ブタン火炎 / DRG / 自然対流熱伝達 / 旋回流 |
|---|
| Outline of Final Research Achievements |
In a former study, it was found that ultra-lean combustion of methane-air and hydrogen air can be realized by using a swirl burner that forms a flame with a large recirculation zone of burned gas. In this study, it was investigated whether ultra-lean combustion is possible or not for propane, n-butane, and n-heptane. As a result, it was found that these fuels can be burned as premixed flames under respective ultra-lean conditions, and that their flame surface shapes are rather flat and like morning glory flowers whose peripheries are accompanied with strong combustion reactions. In this region, each flame surface is concave to the downstream, which enhances the flame surface by the mechanism of thermal-diffusive imbalance for a negatively stretched flame.
|
| Academic Significance and Societal Importance of the Research Achievements |
希薄予混合燃焼は内燃機関の熱効率の向上および窒素酸化物の低減に有効である．しかし予混合火炎には希薄可燃限界が厳然と存在し，それ以下の当量比では通常の方法では全く燃焼せず，また可燃範囲内であってもこの限界に近い条件では消炎が頻発して実機の作動に適さない．本研究の方法で安定な超希薄燃焼が可能になれば，超希薄でなくとも，少なくとも可燃限界に近い希薄条件での作動が現実的になる．本研究の旋回流バーナがそのまま実機に利用できるか否かは明確でないが，分子量が比較的大きな燃料においては火炎の外周部で拡散熱的不均衡により火炎が強化されるという知見は, 実機の開発に重要なヒントを与えると考えられる．
|
