Paper Conference

Proceedings of Building Simulation 2009: 11th Conference of IBPSA

     

APPROXIMATE ANALYTICAL SOLUTION FOR THE HEAT TRANSFER IN PACKED BEDS FOR SOLAR THERMAL STORAGE IN BUILDING SIMULATORS

F. R. Villatoro, J. Pérez, F. Domínguez-Muñoz, J. M. Cejudo-López

DOI: https://doi.org/10.26868/25222708.2009.0709-715
Abstract: Schumann solution for the heating (cooling) of onedimensional packed beds by the passage of a hot (cool) fluid is extended by the incorporation of a small solid thermal conductivity by means of using perturbation methods based on the Laplace transform and a Picard iteration for the Green’s functions for the heat transfer of both phases. The new solution shows smooth heat front propagation through the medium during either the heating or the cooling (depending on its initial temperature) and can be easily incorporated into solar thermal storage simulators currently using Schumann solution, but with increased thermal accuracy. NOMENCLATURE x axial position along the packed bed y nondimensional axial position L length of the solid medium t time coordinate τ nondimensional time coordinate Τf , Τs temperature of fluid and solid, resp. χ nondimensional temperature of the solid ε nondimensional temperature of the fluid ρf , ρs density of fluid and solid, resp. cs specific heat of the solid cf fluid specific heat at constant pressure vf fluid flow velocity h fluid-solid heat transfer coefficient hb fluid-solid boundary heat transfer coefficient γ nondimensional boundary heat transfer ratio λs solid thermal conductivity β2 nondimensional solid thermal conductance p “effective” porosity Tₐ ambient temperature Tf₀ initial temperature of the packed bed n fluid to solid heat capacity ratio
Pages: 709 - 715
Paper:
bs2009_0709_715