Journal: Applied Thermal Engineering, vol. 114, pp. 1053-1063, 2017.
Title: Micro-explosion and burning characteristics of a single droplet of pyrolytic oil from castor seed
Authors: Guna-Bang Chen*, Yueh-Heng Li, Ching-Hsien Lan, Hsien-Tsung Lin, Yei-Chin Chao**
Rank: 7.5% (10/134), SCI, MECHANICS, 2017.
Impact Factor: 3.771
Citation number: 39 (Web of Science)
FWCI: 1.47 (Scopus)
Abstract: 本研究以熱裂解法由蓖麻籽製得蓖麻裂解油，並利用熱重分析探討其裂解與氧化反應，進而評估點火溫度、燃盡溫度與燃燒特性指數等燃燒性質；另以懸浮液滴實驗系統，觀察不同環境溫度下的微爆現象與燃燒模式。蓖麻裂解油為多成分燃料，加熱過程複雜並發生微爆，造成液滴表面變形。依微爆發生時機與強度可分為三個階段：初期低強度、第二階段高強度、最後為中強度微爆。550°C下高強度微爆後釋出更多揮發蒸氣，點火後形成包覆液滴的火焰；燃燒期間微爆持續發生，液滴仍維持近似球形，粒徑變化大致符合d²定律，燃燒速率常數約為1.483 mm²/s。
Heating processes of a droplet at an ambient temperature of 550 C. At 550 C, low boiling components inside the droplet are heated rapidlyand volatilization and nucleation occur instantaneously. The pressure inside the droplet quickly increases, and the droplet begins to swell and burst with a strong micro-explosion at a temperature of about 200 C, accompanied by a certain amount of oil and gas release from the droplet interior. Volatile vapor is released in the previous stage and the flammable mixture is ignited to form a non-premixed flame wrapping around the droplet Combustion accelerates the heating rate of the droplet, and micro-explosion continues to occur because of the nucleation of volatile compounds inside the droplet. The droplet shape is dramatically distorted, and the release of oil and gas affect the appearance of the flame.
Highlights:
- ● 探討單顆蓖麻籽熱裂解油液滴的微爆與燃燒特性。
- ● 依強度辨識出低、高、中三個微爆階段。
- ● 液滴尺寸符合 d² 定律,燃燒速率常數約 1.483 mm²/s。
