5-9 September 2016
Prague Congress Centre
Europe/Prague timezone

P1.140 Three-dimensional condensation regime of steam injected into water at sub-atmospheric conditions

5 Sep 2016, 14:20
1h 40m
Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Foyer 2A (2nd floor), 3A (3rd floor)

Prague Congress Centre

5. května 65, Prague, Czech Republic
Board: 140
Poster G. Vessel/In-Vessel Engineering and Remote Handling P1 Poster session

Speaker

D. Mazed (Department of Civil and Industrial Engineering (DICI))

Description

Important challenges for fusion technology deal with the design of safety systems designed to protect the Vacuum Vessel (VV) in the case of pressurizing accidents like the LOCA (Loss Of Coolant Accident). This accident is caused by the failure of a number of elements of the Tokamak Water Cooling System and may result in relevant consequences for the integrity of the reactor. To prevent or to mitigate structural damages, the solution proposed is a safety system able to quick condense the released steam feeding it into water at sub-atmospheric conditions. This system, connecting the VV to an auxiliary Pressure Suppression Water Tank through a relief line, is equipped with a rupture disc allowing to discharge the released steam. In this framework, an important role is played by the Direct Contact Condensation of steam in water, which is the investigated process to be used to lower the sudden overpressure within the VV. The DCC of steam at atmospheric pressure has been extensively analyzed and experimentally investigated in the past decades for BWR design optimization purposes. Nevertheless, up to date there are no explicit experimental data available for sub-atmospheric pressure conditions. The originality of this study relies on the experimental work that has been done at the DICI of the University of Pisa to provide extended experimental data, necessary to allow a better assessment of DCC of steam phenomena. To analyze the steam condensation regime, the pressure was ranged between 4.2 and 120 kPa while the water pool temperature from 10 up to 85°C. About 300 condensation tests were performed allowing investigation of the combined influence of steam mass flux, water temperature and pool pressure on the steam condensation phenomenon. Procedures adopted and results are duly presented and discussed, focusing upon the efficiency of the steam condensation for all examined conditions.

Co-authors

D. Aquaro (Department of Civil and Industrial Engineering (DICI), University of Pisa, Largo Lucio Lazzarino, 2-56126, Pisa, (PI), Italy) D. Del Serra (Department of Civil and Industrial Engineering (DICI), University of Pisa, Largo Lucio Lazzarino, 2-56126, Pisa, (PI), Italy) D. Mazed (Department of Civil and Industrial Engineering (DICI), University of Pisa, Largo Lucio Lazzarino, 2-56126, Pisa, (PI), Italy) R. Lo Frano (Department of Civil and Industrial Engineering (DICI), University of Pisa, Largo Lucio Lazzarino, 2-56126, Pisa, (PI), Italy)

Presentation Materials

There are no materials yet.