Condensation inside tubes in the presence of high non-condensable concentrations and in transient conditions

The general aim of the separate-effects test program COTINCO is to investigate basic physical phenomena involved in nuclear power plant containment thermal-hydraulics. The main objectives of the COTINCO experiment are: • to investigate physical phenomena involved in condensation of steam inside tubes; • to study the possibility of improving condensation heat transfer even with high concentration of non-condensable (the whole range of gas concentration, from 0 to 100 %, will be examined); • to study the influence of geometry (namely, the tube axis slope) on the heat transfer rate, in presence of high concentration of non-condensable; • to study the effectiveness of devices for venting the condensation tubes; • to develop models and heat transfer correlations for the given conditions; • to produce a data base for modelling condensation with high percentage of non-condensable. The COTINCO test facility consists of a single tube test section with a variable lay-out, crossed internally by steam and air and in communication with external atmosphere, and externally cooled by water. In the paper, the main characteristics of the experimental facility are described, and the experimental test matrix is discussed.