Measurement of Wall Temperature Fluctuations during Thermal Mixing of Non-isothermal Water Streams
2015 (English)In: Proceedings of the 16th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-16), American Nuclear Society, 2015Conference paper (Refereed)
This paper is dealing with measurement of temperature fluctuations during mixing of two water streams in an annular test section at BWR operational conditions. The experiments are simulating conditions existing in a guide tube of BWR control rods, where relatively cold water at about 333 K is mixing with hot water at ~550 K. It is shown that the mixing is causing high amplitude temperature fluctuations in the solid walls of the control rod extender. Using new movable multi-sensors it became possible to obtain a large experimental database, containing wall temperature measurements at 8 azimuthal and 5 axial positions, with 13 thermocouples at each position. In total 520 temperature readings were performed, each lasting about 2 minutes and recording transient temperature with frequency of at least 100 samples per second and with estimated non-calibrated uncertainty less than 3.9 K. The present experimental results can be used to analyze the governing phenomena during thermal mixing and also to validate CFD conjugate heat transfer models of thermal mixing applied to actual reactor geometries.
Place, publisher, year, edition, pages
American Nuclear Society, 2015.
Thermal mixing, thermal fatigue, temperature oscillations
IdentifiersURN: urn:nbn:se:kth:diva-186295ScopusID: 2-s2.0-84962764476OAI: oai:DiVA.org:kth-186295DiVA: diva2:926780
16th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2015; Chicago; United States
FunderSwedish Radiation Safety Authority, 47385
QC 201605122016-05-092016-05-092016-05-12Bibliographically approved