Jet array impingement boiling in compact space for high heat flux cooling

To achieve high heat flux cooling, a distributed confined jet array impingement boiling device was designed and tested by using HFE-7100 as working fluid. The experimental study on the heat transfer characteristics was conducted on smooth silicon surface and micro-pin-firmed surfaces with mass flux ranging from 760 similar to 3040 kg/m(2).s under atmospheric pressure and an inlet subcooling of 40 K. The results indicated that with the increase of the jet velocity, nucleate boiling was suppressed, and the forced convection heat transfer was enhanced. The heat transfer was greatly intensified on micro-pin-finned surfaces with a maximum increase of the heat transfer coefficient of 220 % due to the increase in specific surface area and the number of nucleation sites. Moreover, the critical heat flux (CHF) can reach 280 W/cm(2). The mechanism of CHF improvement was analyzed. The twophase flow structure within the confinement space and capillary wicking effect of the micro-pin-finned surface are superimposed, resulting in two distinct CHF mechanisms. A new correlation with a mean absolute error of 3.5 % for predicting the heat transfer coefficient of the jet impingement boiling was proposed by considering the effect of micro-pin-fin structure on heat transfer.