Abstract
The present paper addresses an experimental study on the development of a microchannel based heat sink to cool photovoltaic panels, mainly focusing on the flow instabilities and on the potential effect of surface microstructuring in heat transfer enhancement and in controlling two-phase flow instabilities in a single microchannel. The results include pressure drop and heat flux maps, obtained combining pressure sensors with high-speed imaging and time resolved thermography. After identifying the flow boiling regimes, the observed phenomena are qualitatively and quantitatively described. Results show that surface cavities per se do not promote active nucleation sites. However, a regular pattern of microcavities enhances heat transfer and promotes the occurrence of a more stable flow in the microchannels.
