In order to use a Periodically operating Two-Phase Thermosyphons (PTPT) in microelectronic equipment cooling, the possibility of a drastic reduction in the scale of the evaporator is considered. In previous studies a miniature PTPT was realised with an internal volume of 352x10-6 m3 and an evaporator volume of 238x10-6 m3. It has shown thermal resistance similar to other unsteady wickless two phase devices as PHPs. The present paper reports an experimental study on the minimum volume of working fluid, which is necessary to obtain a stable operating mode. Our experiments, carried out with FC-72 as working fluid, have shown that the PTPT works in a stable heat transport regime even when the working fluid transported volume is about 3x10-6 m3. The maximum wall temperature stays below 100 °C till a heat flux of 16.2x104 W/m2 is reached. Nevertheless, by keeping the heat flux constant and decreasing the volume of working fluid transported, an increase in total thermal resistance is obtained. This increase rate is, however, small — lower than 25% if the volume of working fluid transported is reduced from 64 to 3x10-6 m3.
On the Possibility of Evaporator Drastic Scale Reduction in a Periodically Operating Two-Phase Thermosyphon
FILIPPESCHI, SAURO;LATROFA, ENRICO MARIA;SALVADORI, GIACOMO
2004-01-01
Abstract
In order to use a Periodically operating Two-Phase Thermosyphons (PTPT) in microelectronic equipment cooling, the possibility of a drastic reduction in the scale of the evaporator is considered. In previous studies a miniature PTPT was realised with an internal volume of 352x10-6 m3 and an evaporator volume of 238x10-6 m3. It has shown thermal resistance similar to other unsteady wickless two phase devices as PHPs. The present paper reports an experimental study on the minimum volume of working fluid, which is necessary to obtain a stable operating mode. Our experiments, carried out with FC-72 as working fluid, have shown that the PTPT works in a stable heat transport regime even when the working fluid transported volume is about 3x10-6 m3. The maximum wall temperature stays below 100 °C till a heat flux of 16.2x104 W/m2 is reached. Nevertheless, by keeping the heat flux constant and decreasing the volume of working fluid transported, an increase in total thermal resistance is obtained. This increase rate is, however, small — lower than 25% if the volume of working fluid transported is reduced from 64 to 3x10-6 m3.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
