Change search
ReferencesLink to record
Permanent link

Direct link
Experimental Study of the Onset of Dryout and Post Dryout Heat Transfer in a Bilaterally Heated Annulus with Flow Obstacles
KTH, School of Engineering Sciences (SCI), Physics, Reactor Technology.
KTH, School of Engineering Sciences (SCI), Physics, Reactor Technology.ORCID iD: 0000-0001-5595-1952
2011 (English)Conference paper (Other academic)
Abstract [en]

New experimental studies of the onset of dryout and post-dryout heat transfer have been performed in the High-pressure Water Test (HWAT) loop at the Nuclear Reactor Engineering division, KTH, Stockholm, Sweden. The experiments have been performed in a bilaterally heated annulus with dimensions 12.7x24.3x3650 mm and with various flow obstacles placed in the exit part of the channel. The objective of the study has been to obtain a new data set of high accuracy which can be used for validation of detailed computational models for prediction of the influence of flow obstacles on the occurrence of dryout and on the post-dryout heat transfer. To meet the objective, in total 88 K-type thermocouples have been installed in the test section, providing both lateral and axial distribution of the heated wall temperature. Several thermocouples have been placed within and in a direct vicinity of selected flow obstacles to obtain a high spatial resolution of the measured temperature field. A thorough analysis of the experimental uncertainties indicates that the accuracy of temperature measurements is better than +/-2 K.

The measurements have been performed at conditions relevant to nuclear reactor safety applications: system pressure in a range from 5 to 9 MPa, mass flux from 500 to 1500 kg/(m2.s) and inlet sub-cooling from 10 to 40 K. The heat flux applied in the test section was limited to not allow the wall temperature to exceed 900 K.

The experimental results indicate that flow obstacles can either remove a dry-patch completely, or reduce the wall temperature downstream of their location. It has been noted that this effect depends on operational conditions and also on the geometry and axial location of the obstacle. In general, stronger influence has been noted for high mass flow rates and for obstacles with a larger projected cross-section area.

Place, publisher, year, edition, pages
National Category
Energy Engineering
Research subject
SRA - Energy
URN: urn:nbn:se:kth:diva-80427OAI: diva2:496313
49th European Two-Phase Flow Group Meeting 2011. ISRAEL. 29th May – 2nd June 2011
QC 20120411Available from: 2012-02-09 Created: 2012-02-09 Last updated: 2012-04-11Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Anghel, IonutAnglart, Henryk
By organisation
Reactor Technology
Energy Engineering

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 41 hits
ReferencesLink to record
Permanent link

Direct link