ISSN Online: 2688-7231
ISBN Online: 978-1-56700-478-6
Proceedings of the 24th National and 2nd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2017)
NUMERICAL INVESTIGATION OF CONDENSATION INDUCED WATER HAMMER TRANSIENTS
Abstract
Direct Contact Condensation (DCC) of steam with cold water occurs during the functioning of various safety systems in water-cooled nuclear reactors. In the Indian PHWRs, the
actuation of Emergency Core Cooling System (ECCS) following a Loss of Coolant Accident causes the injection of sub-cooled water from accumulator tanks into flowing steam/steam water mixture in the reactor inlet and outlet headers. Rapid energy transfer between steam and water causes violent condensation leading to local pressure oscillations. The steam condensation process is generally unstable and several patterns of pressure and fluid oscillations occur, depending upon a number of flow and geometrical parameters. A particular form of DCC is the
Condensation Induced Water Hammer (CIWH) phenomenon that occurs in horizontally oriented pipes. In this paper, a numerical study of CIWH phenomena is presented. The investigations are carried out using system thermal hydraulics code RELAP5/Mod3.4. Parametric studies are conducted with respect to operating and geometrical variables such as the upstream pressure of steam, diameter of the pipe etc. The influence of various parameters on CIWH phenomenon is presented and discussed in this paper.