Tube-CHF database compilation and assessment

This paper describes the methodology of compiling, examining and screening the water CHF database, obtained in uniformly heated vertical tubes. This database has been used as the basis for deriving the CHF look-up table. In addition to the water CHF database, a large number of non-aqueous CHF data have been compiled. These CHF values can be transformed into water-equivalent values by means of fiuid-to-fluid modelling relationships. The non-aqueous data can confirm the reliability of the water data and are therefore used to augment the water database at conditions where water data are scarce or unavailable. Several methods of screening the data to identify outliers or duplicate data may be used. One promising method, used in the present study, is the "Slice Method" where the available data are divided into a large number of slices covering a limited range of pressure, mass flux or quality, for further inspection. Reasons why some CHF data or data sets are considered outliers or duplicates are discussed. These questionable data are not rejected but are labeled separately such that they will not be used as primary data for updating the CHF look-up table. Significant gaps in the database remain present and further work targeted towards certain conditions is still required. An international cooperative effort is underway to fill these gaps. The ultimate objective is to establish an agreed-upon database that can be used for extending the CHF look-up table to conditions where currently data are scarce or unavailable.