The Influence of a Lower Heated Tube on Nucleate Pool Boiling from a Horizontal Tube
NAVAL POSTGRADUATE SCHOOL MONTEREY CA
Pagination or Media Count:
Nucleate pool boiling is an essential part of the vast cooling systems todays combatant ship combat systems are dependent upon. Understanding the mechanisms that influence heat transfer in tube bundles in a liquid pool is the stepping stone for improving these cooling systems. This thesis attempts to bridge the gap between single tube performance and bundle performance by studying the effect of a lower heated tube on the heat transfer from an upper tube in a simple two tube bundle. This study concludes that a nucleating lower tube regardless of the spacings tested between tubes has a significant positive i.e. improvement of heat transfer influence an upon upper tube. This is especially evident for a smooth tube where any hysteresis effects are completely eliminated when the lower tube nucleates at a heat flux of 10 kWIm2 or greater. Furthermore, the only influence for the pitch-to-diameter ratios tested was at the highest heat fluxes for the smooth tubes where a pd of 1.8 was found to give the maximum heat transfer. No such maximum was obtained for the enhanced tubes.
- Air Conditioning, Heating, Lighting and Ventilating
- Marine Engineering