This paper presents an experimental study of ﬂow boiling heat transfer in a microchannel heat sink. The dielectric Molecular weight (g/mol). ﬂuid Fluorinert FC-77 is used as the boiling liquid after it is fully degassed. The experiments were performed at three ﬂow rates ranging from 30–50 ml/min. The heat transfer coefﬁcients, as well as the critical heat ﬂux (CHF), were found to increase with ﬂow rate. Wall temperature measurements at three locations (near the inlet, near the exit, and in the middle of heat sink) reveal that wall dryout ﬁrst occurs near the exit of the microchannels. The ratio of heat transfer rate under CHF conditions to the limiting evaporation rate was found to decrease with increasing ﬂow rate, asymptotically approaching unity. Predictions from a number of correlations for nucleate boiling heat transfer in the literature are compared against the experimental results to identify those that provide a good match. The results of this work provide guidelines for the thermal design of microchannel heat sinks in two-phase ﬂow.
Critical heat flux (CHF), electronics cooling, flow boiling heat transfer, microchannel heat sink.
Date of this Version
T. Chen and S. V. Garimella, “Flow Boiling Heat Transfer to a Dielectric Coolant in a Microchannel Heat Sink,” IEEE Transactions on Components and Packaging Technologies Vol. 30, pp. 24-31, 2007.