| Summary: | 碩士 === 國立雲林科技大學 === 機械工程系碩士班 === 97 === A serial of systematic numerical simulations of the water in the small size of pool boiling is conducted to study the pressure and structure of heated surface effect on the heat flux, critical heat flux and boiling curve. The phenomena of nucleate, bubble formation and depart from surface is observed by measuring the vapor bubble diameter, nucleate and departure time in various environmental pressure and different structures.
The result is the heat flux will be increase with pressure, and superheat temperature of the critical heat flux will be changed too. Then, nucleate time will be delayed and the bubble depart diameter will be decreased. The structures of heated surface in paralel and cross fin types make boiling activities more rigorous results in the nucleate happens earlierly and the heat flux was increase 1.2 times.
Finally, the above basic research results and simulation approaches are applied on simulating the boiling inside of the evaporator, a major component of loop thermosyphon system. Three structure of heated surface are employed to calculate their heat flux and mass flow rate of the evaporator.
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