2016 Fiscal Year Final Research Report
Mechanism of critical heat flux enhancement in boiling of binary mixtures
| Project/Area Number |
25420141
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Thermal engineering
|
|---|
| Research Institution | Hokkaido University |
|---|
Principal Investigator |
|
|---|
| Project Period (FY) |
2013-04-01 – 2017-03-31
|
| Keywords | 沸騰 / 限界熱流束 / 二成分流体 / 濃度分布 / マランゴニ対流 |
|---|
| Outline of Final Research Achievements |
To examine the mechanism of CHF enhancement with binary mixtures, the local concentrations of 2-propanol was deduced based on the temperatures near the heating surface measured using a micro thermocouple in pool boiling on an upward-facing heating surface for 2-propanol/water mixtures. It was found that the concentration and surface tension vary strongly near the heating surface. The boiling behaviors of the 3mol% of 2-propanol/water mixture were observed using a transparent surface via a total reflection technique. It was clarified that drying behaviors of the surface were quite different between water and the mixture. This difference is probably due to a strong Marangoni convection induced by non-uniform surface tension distribution near the heating surface. It is suggested that the this Marangoni effect leads to promotion of primary bubble detachment, and therefore, formation of thicker macrolayer, resulting in the CHF enhancement of 2-propanol/water mixtures.
|
| Free Research Field |
工学
|
