ANALYSIS ON HYSTERESIS IN NUCLEATE POOL BOILING HEAT-TRANSFER

Many experiments reported for nucleate pool boiling heat transfer from microelectronic assemblies or porous surfaces in dielectric fluids have shown the existence of hysteresis phenomenon, which is known as a temperature overshoot (TOS) in boiling incipience and constrains engineering applications. Here, theoretical analysis has been carried out. It confirms that hysteresis may occur during both the boiling incipience and the boiling development. Hence, a new type of hysteresis, termed Temperature Deviation (TD), is described. Using thermodynamic nucleation, the physical mechanisms for both TOS and TD are analyzed in detail. Three parameters for quantitatively understanding the hysteresis phenomenon and possible measures for remedying it are proposed and discussed.