2004 Fiscal Year Final Research Report Summary
Effect of surface condition on high heat flux boiling phenomena in various liquids
| Project/Area Number |
15560728
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Nuclear engineering
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| Research Institution | Kobe University (2004)
神戸商船大学 (2003) |
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Principal Investigator |
FUKUDA Katsuya Kobe University, Faculty of Maritime Sciences, Professor, 海事科学部, 教授 (10127417)
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| Co-Investigator(Kenkyū-buntansha) |
LIU Qiusheng Kobe University, Faculty of Maritime Sciences, Associate Professor, 海事科学部, 助教授 (80294263)
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| Project Period (FY) |
2003 – 2004
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| Keywords | surface condition / high wettability / rapid depressurization / heterogeneous spontaneous nucleation / critical heat flux / pool boiling / flow boiling |
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| Research Abstract |
1.Research on high heat flux boiling on horizontal test heater with various surface conditions in a pool of water
The subcooled pool boiling critical heat fluxes on the horizontal cylinders with mirror finished and rough surfaces in a pool of water at the pressures up to about 2 MPa for the subcoolings up to 60 K were measured. The results compared with corresponding data for the cylinder with commercial surface already obtained for the same experimental conditions. The CHF values for rough surface were good agreement with those obtained by the correlation corresponding to commercial surface based on hydrodynamic instability (HI) and heterogeneous spontaneous nucleation (HSN) curves.
2.Research on high heat flux boiling on horizontal test heater with various surface conditions in various wetting liquids
Steady-state and transient CHFs were measured by using a horizontal cylinder in a pool of water and highly wetting liquid such as Ethanol with various periods for wide ranges of subcooling
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and pressure. The steady-state CHFs were expressed by the correlation base on heterogeneous spontaneous nucleation at various pressures. The transient CHFs depending on the periods were divided into two principal groups. The CHFs increase with an increase in subcooling at pressures and they are independent of pressures at high subcoolings.
3.Research on transient boiling due to rapid depressurization on horizontal heater in a pool of wetting liquid
The characteristics of the transient boiling processes for the transitions from the initial heat fluxes in natural convection and nucleate boiling regimes to film boiling regime caused by the exponentially decreasing system pressures using measured heat transfer processes for ethanol including transient CHFs caused by the rapid depressurizations decreasing exponentially with the periods were clarified.
4.Research on subcooled flow boiling CHF with high heat flux enhancement.
In the relation of deep research, the subcooled water flow boiling CHFs versus outlet subcoolings for a flow velocity with outlet pressures as a parameter in the horizontal and vertical tubes with enhancement having flowing subcooled water were clarified using the existing databases expanding quite recently derived the correlations representing the subcooled water flow boiling CHF versus outlet subcooling in tubes with various tube inside diameter and length-to-diameter ratios for a flow velocity with outlet pressure as a parameter. Less
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