Spray Cooling

Spray Cooling

Thermal management of electronic components has always been a challenging task since the advent of the micro-packaging technology. Nano-sized transistors have successfully reduced the size of the microprocessor chips. However, the miniaturization has also increased the power density within the electronic chip tremendously. High power density directly relates to high heat flux generated by the electronic chips. Novel cooling techniques are required for the effective removal of excess heat which is critical for the reliable operation of the electronic device. State-of-the-art direct cooling technologies include: pool boiling thermosyphons, evaporative cooling, jet impingement and spray cooling. Amongst all the available technologies, spray cooling has an inherent advantage of maintaining uniform surface temperature while using a low fluid inventory.

The present state of knowledge identifies four possible heat transfer regimes in spray cooling: (a) flooded (b) thin film (c) partial dryout (d) dryout. While it is safe to operate in the first three regimes, transitioning from partial dryout to dryout regime would force the chip to attain the peak heat flux (commonly, known as critical heat flux (CHF)). This, in turn, could possibly burn out the chip and possibly pose a threat to the whole electronic system. Our objective is to investigate the effect of micro- and nano- structured surfaces on the heat transfer mechanisms of spray cooling. A counter-flow nozzle will be used to generate liquid sprays and temperature measurements from a T-type thermocouple will be used to study the heat transfer characteristics.