Reporting Items for Flow-Boiling Critical Heat Flux Experiments in Water: A Proposal Open to Revision

Critical heat flux (CHF) data from different laboratories disagree by more than their stated uncertainties, and the 2006 look-up table and most correlations cannot say why, because the papers behind them often leave out how the experiment was done. This record proposes eleven items that a flow-boiling CHF experiment in water should report: wall thickness, wall material, heating method, detection method and its exact criterion, the approach to CHF, the measured test-section pressure, loop stability, water condition, coolant, uncertainty with repeats, and tabulated data. Each item comes with the evidence behind it and a statement of how that evidence was read (in full, abstract only, or software-agent extraction). The evidence is strongest for loop stability (a compressible volume upstream cut burnout by as much as 80%) and wall thickness (6 to 58% in same-rig tests, with the direction not settled), and thin for heating method, dissolved gas and coolant, which are under test in the version 8 pre-registration. An analysis of the NRC CHF data file finds five laboratories reporting a single pressure for every row near atmospheric, and notes that the 2006 table stops at 100 kPa. Bundle laboratories that shared conditions, procedure and one detection criterion agreed within about 1%, which supports the point that controlled and reported conditions bring laboratories into agreement. The list is version 1.0 and is open to revision: it will be updated as new versions of this record when the version 8 test is scored, when new evidence appears, and when readers point out missing, redundant or impractical items. Comments are invited. Archive SHA-256: bc7a64890b53c58581feb6cf804018cf15509713e9bcf1d27d22dedf1e09293c