Ionut Gheorghe Anghel

Study of Post Dryout Heat Transfer in Annulus With Flow Obstacles

The purpose of this paper is to present the experimental setup, experimental method and results of the recent post-dryout heat transfer investigations in an annulus with pin spacers. The experiments were performed in the thermal-hydraulic laboratory at the Royal Institute of Technology (KTH), Stockholm, Sweden. The experimental facility has an annular test section which consists of two double-heated concentric tubes manufactured of Inconel 600. Five levels of pin spacers were installed along the test section to keep the rod and the tube equidistant during experiments. The experimental matrix includes measurements of wall temperature distributions for single phase and two-phase flows, for both convective boiling and post-dryout heat transfer regimes. The influence of variations in mass flux (500–1500) kg/(m2 s) and inlet subcooling 10 and 40 K at system pressure of 7 MPa were investigated. The experimental results indicate that post dryout heat transfer is influenced by the pin spacers. In particular it has been observed that the dry patch appearing in the test section can be quenched downstream of the pins-spacer. The current results provide additional experimental database which can be used for validation of post-dryout heat transfer models including the flow obstacle effects.Copyright

Experimental Investigation of the Influence of Flow Obstacles on Post-Dryout Heat Transfer in an Annulus

This paper describes the experimental setup, instrumentation and procedures which have been developed in the thermal-hydraulic laboratory at the Royal Institute of Technology (KTH), Stockholm, Swed ...

Validation of the TRACE Code Against Post-Dryout Experiments in Tubes and Annuli

The present paper presents results of the TRACE code assessment against post dryout experimental data obtained in tubes and annuli. The investigations have been focused on the experiments carried out at 70 bar pressure, 10 K inlet subcooling and the mass flux variation between 500–2000 kg/(m2 s). Various axial power distributions (uniform, inlet peaked, middle peaked, and outlet peaked) have been used in the tube geometry. Uniform power distributions, with various ratios between the inner and the outer power have been used in the annulus geometry. The validation results indicated that the discrepancies between measured and calculated data are in a range of ±20%. In addition a sensitivity study has been performed in which the influence of several parameters (including cell size and boundary conditions) on computational results have been investigated.Copyright