A passive technique for cooling heat-dissipating integrated circuits involves submerging the ICs in a low boiling point dielectric fluid. Vapor generated in cooling the circuits is condensed on vertical plates suspended in the vapor cavity above the liquid. The temperature of the plates is maintained below the saturation temperature and during steady-state operation a balance is established between the rate of heat transfer to the condenser plates and the rate of heat dissipation by the ICs.

Consider conditions for which the 25-mm² surface area of each IC is submerged in a fluorocarbon liquid for which T_sat = 50°C, p₁ = 1700 kg/m³, c_p.1 = 1005 J/kg ∙ K, μ₁ = 6.80 x 10^-4 kg/s ∙ m, k, = 0.062 W/m ∙ K, Pr₁ = 11.0. σ = 0.013 kg/s², h_fg = 1.05 x 10⁵ J/kg, C_s.f = 0.004 and n = 1.7. If the integrated circuits are operated at a surface temperature of Ts = 75°C, what is the rate at which heat is dissipated by each circuit? If the condenser plates are of height H = 50 mm and are maintained at a temperature of Tc = 15°C by an internal coolant, how much condenser surface area must be provided to balance the heat generated by 500 integrated circuits?

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Condenser plates, T. Vapor cavity- Integrated circuit (IC), T, Dielectric liquid