DYNAMICS OF THE FLOWS IN MICRO-CHANNELS OF A CAPILLARY PUMPED LOOP (CPL) EVAPORATOR

摘要

Cooling of electronic components is often limited by space availability and power consumption. Capillary-pumped loops (CPL) are utilized to achieve a coolant circulation via self-activated capillarity (Faghri, 1995). However, CPL is extremely unstable due to a nonlinear feedback among capillarity, viscous force, and heat transfer. Conventional refrigeration theories, which usually allow a larger pressure jump due to an external pumping, failed to explain the CPL cycle. The dynamics of a flow through a CPL cooling cycle is investigated with a particular attention to the flow in the micro-channels. Full numerical approaches, by which multi-component multi-phase flows are solved, tend to obscure the engineers from identifying outstanding design parameters. Instead, one here adopts several simplified semi-analyitic approaches, namely, models based on single-phase flows with discrete zones of heating and cooling. The analytical and numerical results could explain some general tendencies in the dynamical features like dry-out and flooding. However, the problem still requires closer and more realistic modeling.