High power density two-phase cooling in microchannel heat exchangers

Author:

Kwon, Beomjin  Maniscalco, Nicholas I.  Jacobi, Anthony M.  King, William P.  

Journal:

APPLIED THERMAL ENGINEERING

Issue Date:

2019

Abstract(summary):

This paper reports two-phase cooling in compact cross-flow microchannel heat exchangers with high power density up to 180 W/cm(3). The performance is enabled by high-speed air flow through microchannels and two-phase condensation of refrigerant R245fa. The heat exchangers were realized in 1 cm(3) blocks of copper alloy, using micro-electrical-discharging machining. Two heat exchanger designs were analyzed, fabricated, and tested. The first device has 150 air-side channels of diameter 520 mu m, and the second device has 300 air-side channels of diameter 355 mu m. In both cases the refrigerant channels are 2.0 x 0.5 mm(2). The heat exchangers were operated with Reynolds number between 7500 and 20,500 for the air flow and with mass flux between 330 and 750 kg/m(2) s for the refrigerant flow. The refrigerant temperature at the channel entrance was 80 degrees C, which is near the maximum operating temperature for some electronic devices. For comparison purposes, the devices were also tested with single-phase refrigerant flows. This work demonstrates the potential of high power density heat exchangers that leverage advanced manufacturing technologies to fabricate miniature channels.

Page:

1271---1277