抄録
Due to the considerably reduced boiling point, organic fluids such as ethanol provide an attractive alternative to water as the working fluid in two-phase thermal management systems for high-heat-flux applications. The state-of-the-art enhancement methods for ethanol boiling normally involve surface structure engineering. Here we report, for the first time, enhancement of nucleate boiling of ethanol using wettability-patterned surfaces. By depositing onto a polished copper surface an array of circular spots of superamphiphobic coating of modified halloysite nanotubes (HNT) with fluoropolymer, which was shown to repel low-surface-tension fluids, we managed to create a meaningful biphilic pattern of alternating hydrophobicity (with ethanol contact angle exceeding 100°) and hydrophilicity (with contact angle close to 0°) on the surface. Boiling heat transfer was found to be improved dramatically on the coated surface. Specifically, the onset of nucleate boiling was found to drop by more than 35%. Moreover, at 20 K surface superheat (above the boiling point), a maximum heat transfer enhancement over 300% compared with a plain copper surface occurred on the surface with a pitch-to-spot ratio close to 2.5. The significantly increased heat transfer rate of the biphilic surfaces could be attributed to facilitated bubble nucleation and stronger agitation effect.
| 元の言語 | 英語 |
|---|---|
| ページ（範囲） | 325-331 |
| ページ数 | 7 |
| ジャーナル | Applied Thermal Engineering |
| 巻 | 149 |
| DOI | |
| 出版物ステータス | 出版済み - 2 25 2019 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Energy Engineering and Power Technology
- Industrial and Manufacturing Engineering
これを引用
Enhanced pool boiling of ethanol on wettability-patterned surfaces. / Shen, Biao; Hamazaki, Takeshi; Ma, Wei; Iwata, Naoki; Hidaka, Sumitomo; Takahara, Atsushi; Takahashi, Koji; Takata, Yasuyuki.
：: Applied Thermal Engineering, 巻 149, 25.02.2019, p. 325-331.研究成果: ジャーナルへの寄稿 › 記事
}
TY - JOUR
T1 - Enhanced pool boiling of ethanol on wettability-patterned surfaces
AU - Shen, Biao
AU - Hamazaki, Takeshi
AU - Ma, Wei
AU - Iwata, Naoki
AU - Hidaka, Sumitomo
AU - Takahara, Atsushi
AU - Takahashi, Koji
AU - Takata, Yasuyuki
PY - 2019/2/25
Y1 - 2019/2/25
N2 - Due to the considerably reduced boiling point, organic fluids such as ethanol provide an attractive alternative to water as the working fluid in two-phase thermal management systems for high-heat-flux applications. The state-of-the-art enhancement methods for ethanol boiling normally involve surface structure engineering. Here we report, for the first time, enhancement of nucleate boiling of ethanol using wettability-patterned surfaces. By depositing onto a polished copper surface an array of circular spots of superamphiphobic coating of modified halloysite nanotubes (HNT) with fluoropolymer, which was shown to repel low-surface-tension fluids, we managed to create a meaningful biphilic pattern of alternating hydrophobicity (with ethanol contact angle exceeding 100°) and hydrophilicity (with contact angle close to 0°) on the surface. Boiling heat transfer was found to be improved dramatically on the coated surface. Specifically, the onset of nucleate boiling was found to drop by more than 35%. Moreover, at 20 K surface superheat (above the boiling point), a maximum heat transfer enhancement over 300% compared with a plain copper surface occurred on the surface with a pitch-to-spot ratio close to 2.5. The significantly increased heat transfer rate of the biphilic surfaces could be attributed to facilitated bubble nucleation and stronger agitation effect.
AB - Due to the considerably reduced boiling point, organic fluids such as ethanol provide an attractive alternative to water as the working fluid in two-phase thermal management systems for high-heat-flux applications. The state-of-the-art enhancement methods for ethanol boiling normally involve surface structure engineering. Here we report, for the first time, enhancement of nucleate boiling of ethanol using wettability-patterned surfaces. By depositing onto a polished copper surface an array of circular spots of superamphiphobic coating of modified halloysite nanotubes (HNT) with fluoropolymer, which was shown to repel low-surface-tension fluids, we managed to create a meaningful biphilic pattern of alternating hydrophobicity (with ethanol contact angle exceeding 100°) and hydrophilicity (with contact angle close to 0°) on the surface. Boiling heat transfer was found to be improved dramatically on the coated surface. Specifically, the onset of nucleate boiling was found to drop by more than 35%. Moreover, at 20 K surface superheat (above the boiling point), a maximum heat transfer enhancement over 300% compared with a plain copper surface occurred on the surface with a pitch-to-spot ratio close to 2.5. The significantly increased heat transfer rate of the biphilic surfaces could be attributed to facilitated bubble nucleation and stronger agitation effect.
UR - http://www.scopus.com/inward/record.url?scp=85058370822&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85058370822&partnerID=8YFLogxK
U2 - 10.1016/j.applthermaleng.2018.12.049
DO - 10.1016/j.applthermaleng.2018.12.049
M3 - Article
AN - SCOPUS:85058370822
VL - 149
SP - 325
EP - 331
JO - Applied Thermal Engineering
JF - Applied Thermal Engineering
SN - 1359-4311
ER -