Experimental Study of Boiling in Porous Media

Following a long-lasting failure in the cooling system of a pressurized water reactor (PWR), the superheated core can be efficiently cooled down by reflooding. The macroscopic model used at the French Institute of Radioprotection and Nuclear Safety (IRSN) to simulate this process is based on strong assumptions on the microscopic flow patterns. This paper describes the experimental setup designed for the study of boiling in porous media with the emphasis on various pore-scale boiling regimes. The final experimental setup is a two-dimensional porous medium made of 392 cylinders randomly placed between two ceramic plates. Each heating cylinder is a RTD probe (Resistance Temperature Detector), that can give thermal measurements in every point of the test section as well as heat generation. This paper presents preliminary results: pool boiling is characterized for a single cylinder mounted in the test section and reflooding of a line of 9 cylinders is observed.