Quasi-steady nucleate boiling on a horizontal cylinder in liquid He I caused by large stepwise heat input, whose height was far beyond the value corresponding to the steady critical heat flux, was investigated. It was confirmed that quasi-steady nucleate boiling exists with a certain life at the sta
Comparison of transient heat transfer characteristics for large stepwise heat input in He I and He II
โ Scribed by M. Shiotsu; K. Hata; A. Sakurai
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- English
- Weight
- 539 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0011-2275
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โฆ Synopsis
The characteristics of transient heat transfer on horizontal cylinders in He I and He II caused by various large stepwise heat inputs are described for wide ranges of system pressure and liquid head. Characteristics such as the quasi-steady nucleate boiling with a lifetime for He I, and the quasi-steady Kapitza conductance with a lifetime for He II for ideal step inputs, are compared. Steady-state critical heat flux for He II increases with increased subcooling and becomes much higher than that for He I. In steady-state heat transfer for highly subcooled He II, the surface temperature jump at the critical heat flux is negligibly small. He II has good stability characteristics for large local thermal disturbances, and these become significantly better with increased subcooling.
๐ SIMILAR VOLUMES
Kapitza conductance in steady and transient boiling heat transfer on a horizontal 0.2mm diameter test wire was estimated based on the measured Kapitza conductance value for the same surface in He II. The He II experiments performed are for liquid temperatures ranging from 1.8 to 2.1 K under atmosphe