On the Pattern of Water Penetration into a Hot Particle Bed

Pressure drop and average void fraction measurements for two-phase flow through highly permeable porous media

“…Several experimental investigations have been carried out to help modeling. Dry-out experiments (Hardee and Nilson, 1977;Dhir and Catton, 1977;Lipinski, 1984;Decossin, 1999) and reflood tests (top flooding: (Cho et al, 1984;Ginsberg et al, 1982;Tutu et al, 1984a;Tung and Dhir, 1988); bottom flooding: (Hall and Hall, 1981;Tutu et al, 1984c;Tung and Dhir, 1986)) have been performed, providing global parameters: outlet steam flow rate, quench front velocity, etc. The instrumentation was scarce so that only 0D/1D models have been developed, based on the counter current flow limitation (CCFL) and on correlations for the friction laws (Lipinski, 1982;Reed, 1982;Hu and Theofanous, 1991;Tung and Dhir, 1988;Schulenberg and Müller, 1987).…”

The impact of thermal non-equilibrium and large-scale 2D/3D effects on debris bed reflooding and coolability

“…First, the liquid slowly penetrates into the bed leaving behind the quench front channels and pockets of dry particles (filmboiling). Armstrong et al (1981Armstrong et al ( , 1982 and Cho et al (1984) have observed, in similar experiments, that the water preferentially penetrates the center part of the debris bed and leaves the outer part dry. The velocity of the downward quench front is constant although it varies with particle diameters and initial bed temperature.…”

“…On the other hand, the reflooding of hot debris beds has received less attention. Some experimental studies are available (Armstrong et al, 1982(Armstrong et al, , 1981Cho et al, 1984;Ginsberg, 1982Ginsberg, , 1985Ginsberg et al, 1986;Tutu et al, 1984;Konovalikhin et al, 2000) and a few models have been proposed (Petit et al, 1999;Sozen and Vafai, 1990). The existence of temperature differences between the solid particles, the water and the steam makes modeling and experimental measurements more difficult.…”

Modeling of inertial multi-phase flows through high permeability porous media: Friction closure laws

“…Interfacial friction term in generalized Ergun models (Pa/m) F ββ Inertial correction tensor for the β-phase Integral 0D/1D models for steam-water boiling flows in porous media, involving averaged conservation equations -mass, energy, momentum-and closure laws -for the energy and momentum equations-, have been developed and extended afterwards to 2D/3D situations, assuming homogeneity and isotropy conditions for the debris bed ( Fichot et al, 2006 ). Their validation is based on predictions of global parameters (steam production, bed temperature) measured in integral experiments of debris bed cooling: dryout heat flux, in dry-out experiments ( Decossin, 1999;Dhir and Catton, 1977;Hardee and Nilson, 1977;Lipinski, 1984 ), or quench front progression velocity, in reflood experiments -top flooding ( Cho et al, 1984;Ginsberg et al, 1982;Tung and Dhir, 1988;Tutu et al, 1984b ) or bottom flooding ( Hall and Hall, 1981;Tung and Dhir, 1986;Tutu et al, 1984a ), and global steam production. The available models are based on the use of macro-scale equations for energy or momentum balances based on separate closures, e.g.…”