Dry ice sublimation spray cooling technology provides significant advantages for thermal management and efficient heat dissipation in high-power electronic chips because of its high latent heat of sublimation, high heat flow density, and rapid cooling speed. A ribbed structure of the surface increases the overall effective area that may be used for convective heat transfer. Such a structure can be used for the heat dissipation of electronic components, as it simultaneously lowers the thermal resistance. This study uses ribbed structures and dry ice sublimation spray cooling to examine the effect of ribbed heat sources on heat transfer. A two-phase flow theoretical model is built on the basis of the dry ice sublimation spray cooling heat transfer process for ribbed surfaces with high heat sources. Heat source copper blocks with a smooth surface, a straight-rib surface, and a cylindrical-rib surface are designed and processed accordingly. For the different influencing factors of the cooling process, the effect of these three heat source copper blocks on the heat transfer characteristics of dry ice sublimation spray cooling was investigated. Our research demonstrates that identical parameter settings, a heat source with a ribbed surface shows better heat transmission performance than the heat source without a ribbed surface. Additionally, the cylindrical-rib surface shows better heat transfer effectiveness than the straight-rib surface. The cooling efficacy of dry ice spray on ribbed surfaces may be improved by increasing the mass flow rate of carbon dioxide and decreasing the continuous heating power while keeping all other parameters constant. As a result, the heat transfer coefficient and flux both increase. The cylindrical-rib surface requires the shortest amount of time (60 s) to reach equilibrium from the initial temperature of 345 K for the spray height, mass flow rate of dry ice spray, and the constant heating power of 5 cm, 17 g/s, and 30 W, respectively. The ideal average temperature of heat source surface upon attaining equilibrium is 275.3 K, and the heat flow and heat transfer coefficients are 860,406 W/m2 and 8653.6 W/(m2·K), respectively.
