Three-phase Heat Transfer

Phase-change heat transfer involves the exchange of thermal energy when a substance transitions between different phases, such as solid to liquid (melting), liquid to vapor (boiling), or vice versa. During phase-change, energy is absorbed or released without a change in temperature. In particular, boiling is highly efficient due to the large latent heat of vaporization, allowing for dissipative heat fluxes on the order of q′′ ∼ 10–100 W/cm². However, during boiling, once the temperature exceeds a critical threshold, a vapor film forms between the heated surface and the liquid, suppressing effective nucleate boiling which reduces heat transfer efficiency so that q′′ ∼ 1 W/cm². This critical temperature limitation prompted our exploration of three-phase heat transfer. In three-phase heat transfer, energy is transferred between the solid, liquid, and vapor phases; all of which coexist simultaneously. In this study, we define and investigate three-phase heat transfer by examining ice on a superheated substrate. We explore the use of ice as a quenchant and our findings indicate that dissipative heat fluxes for our three-phase system are an order of magnitude larger than for classical boiling (q′′ ∼ 1,000 W/cm²). This is due to the inherent 100 °C temperature differential across the meltwater film, which dissipates q′′ ∼ 100 W/cm² via conduction (and subsequent ice melting) and an additional q′′ ∼ 100 W/cm² for sensible heating of the meltwater. We propose experiments to measure the dissipative heat flux of a tall and pressurized ice column during three-phase heat transfer. Furthermore, we discuss potential avenues for future research of three-phase heat transfer at high superheats.