DERIVATIONS OF CORRELATION AND MODEL OF TRANSITION BOILING HEAT TRANSFER (LIQUID-SOLID CONTACT MODEL FOR TRANSITION BOILING HEAT TRANSFER IN HIGH WALL SUPERHEAT)

摘要

The transition boiling heat transfer was examined through derivations of correlation and model. The correlation of liquidsolid contact fraction in transition boiling was derived by focusing on the dimensionless wall temperature, Θ= (T_w-T_(CHF)) / (T_(MHF)-T_(CHF)); the following correlation was obtained from experimental results for water, R-113 and LN_2: Γ=1.000-0.9120Θ-0.1343Θ~2, where q_(tb)=q_(CHF)Γ+q_(MHF)(1-Γ). In the present model, considering a pseudo liquid-solid contact right after detachment of a bubble from liquid-vapor interface resulted from Rayleigh-Taylor instability, transient heat conduction was analyzed in it three dimensionally. Liquid-solid contact time and área were given by the present correlation of the fractions of liquid-solid contact: τ_(contact) = 0.3Γ_t, A_(wet)=15 x 15 Γ_a, Γ = Γ_tΓ_a = 1.000-0.9120Θ-0.1343Θ~2,where Θ = (T_w -T_(CHF))/(T_(MHF)-T_(CHF))- The prediction by the present model was in agreement with the present experimental data for water.