Heat transfer simulation in a thermochemical solar reactor based on a volumetric porous receiver

Abstract

A 1 kW thermochemical solar reactor/receiver fitted with a porous ceramic foam structure is studied numerically to predict the thermal transfers inside the volumetric solar receiver. This reactor is devoted to the production of hydrogen from two-step thermochemical cycles based on mixed metal oxides, and it features a porous media coated with the reactive ferrite material

Effects of key factors on solar aided methane steam reforming in porous medium thermochemical reactor

“…Their prevalence over porous medium reactors for solar driven methane reforming was sought to higher porosity to allow CSI to penetrate deeper in the volume of porous medium. During the following decades, ETH [18], CNRS-PROMES laboratory [19] and CETRH/CPERI laboratory [20] had manufactured many types of porous medium solar thermochemical reactors coated with catalyst to absorb CSI to maintain the operational temperature for methane reforming reaction. Gokon et al had adopted metallic porous media reactor coated with Ru/g-Al 2 O 3 catalyst for solar methane reforming reaction [21].…”

Modelling of solar thermochemical reaction systems

“…The p 1 approximation does not require significantly more computational expense-a Helmholz equation must be solved everywhere in space-but can handle media that are more optically thin than the RD (Modest, 2013). The p 1 approximation has been used to study several STRS designs based on porous materials (Bala Chandran et al, 2015b;Villafán-Vidales et al, 2011;Wang et al, 2014a,b).…”

“…Thus, one energy conservation equation (15) is solved for each phase. The use of local thermal non-equilibrium (LTNE) appears widely in the literature when using homogenisation Belghit, 2011a, 2011b;Groehn et al, 2016;Kenarsari and Zheng, 2014;Villafán-Vidales et al, 2011;Wang et al, 2014a;Wang et al, 2014b;Zedtwitz et al, 2007;Zedtwitz and Steinfeld, 2005) or when the phases are resolved individually (Abanades et al, 2007;Oles and Jackson, 2015), though there are examples of high solid fraction studies in fixed beds where the single temperature-or local thermal equilibrium (LTE)-assumption is made (Lapp et al, 2013;Lapp and Lipiń ski, 2014;Lu et al, 2016;Martinek et al, 2014). The approximation of LTE is valid when any local temperature differences between a fluid and a solid are much smaller than the temperature differences that appear in the whole system.…”

“…(6) to account for momentum losses in the porous material as seen in (Bader et al, 2015;Bala Chandran et al, 2015a;Bala Chandran et al, 2015b;Lu et al, 2016;Villafán-Vidales et al, 2011;Wang et al, 2014a,b). The use of the Darcy term in Eq.…”

“…Enthalpy of formation may also appear as a source term in the energy balance equation when considering a single-phase equation only. Enthalpy of reaction can be available experimentally or estimated by thermodynamic database software as demonstrated in (Villafán-Vidales et al, 2011). The temperature dependence of reaction rates is generally handled by assuming an Arrhenius-type law (see Section 3.2): Lipiń ski, 2012, 2011;Haussener et al, 2009;Lipiń ski and Steinfeld, 2004;Müller et al, 2008;Oles and Jackson, 2015;Schunk et al, 2009b;2009a;Villafán-Vidales et al, 2015;Yue and Lipiń ski, 2015a,b,c;Zedtwitz et al, 2007;Zedtwitz and Steinfeld, 2005).…”