CONDENSATION CORRELATION FOR A VERTICAL PASSIVE CONDENSER SYSTEM

A condensation correlation was developed for vapor and air mixture condensation in a vertical tube based on experimental data and a mechanistic model based on heat and mass analogy model. Parametric computations were performed using a heat and mass analogy model for various operating parameters of the passive condenser system. The parameters investigated were noncondensable gas mass fraction W_bulk, mixture gas Reynolds number Re_G, and Jacob number Ja_G. An alternating conditional expectation (ACE) regression algorithm was used to develop the condensation heat transfer correlation for the passive condenser. A total of 102 600 dat apoints was used as input to the ACE. Local condensation heat transfer cor-relations in terms of Nusselt number (Nu_cond) obtained were: Nu_cond = 0.08 _bulk-0.9Re_G^1.1·exp(-42.5Ja _G) for turbulent flow and Nu_cond = 160W _bulk^-0.9·exp(-42.5Ja_G)for laminar flow. The correlations are valid for 0≤ W_bulk ≤ 0.5, 0 ≤ Re_G ≤4 ×10⁴, 0.002 ≤ Ja_G ≤ 0.05. The prediction of the developed correlation agreed well with the available experimental data. The correlations are useful in predicting the heat transfer characteristics of a passive containment cooling system (PCCS) in an economic simplified boiling water reactor. These correlations apply to the three modes of PCCS operation, namely through-flow mode, complete condensation mode, and cyclic condensation and venting mode.