abstract
The performances of well-known porous metal/metalloid oxide adsorbents (zeolite 13X, zeolite 4A and silica gel) and less explored Engelhard titanosilicate ETS-10 for water adsorption heating systems (AHSs) were compared with the aid of computational modelling and simulations. The developed model contemplated adsorption equilibrium, one-dimensional heat and mass transfer in the bed, external heat transfer limitations, and intraparticle mass transport. The pair zeolite 13X/water seemed most promising for the AHS partly due to a higher amount of heat generated per cycle, and favourable water-adsorption isotherm features. Based on sensitivity studies, for zeolite particle diameters in the range 0.2-0.6 mm, the coefficient of performance was 1.48 and the specific heating power was in the range 1141-1254 W Kg(s)(-1) Aiming at inferior computational and numerical efforts, the impact of considering some simplified postulations (e.g. constant thermal conductivity of the adsorbent; constant isosteric heat of adsorption; constant linear driving force coefficient), while ensuring comparable predictions of the performances of the AHSs, was successfully investigated. (C) 2016 Elsevier Ltd. All rights reserved.
keywords
THERMAL-ENERGY STORAGE; MASS-TRANSFER; WORKING-CONDITIONS; PACKED-BEDS; SILICA-GEL; ZEOLITE; PUMP; CONDUCTIVITY; ISOTHERMS; DIFFUSION
subject category
Thermodynamics; Energy & Fuels; Engineering; Mechanics
authors
Pinheiro, JM; Salustio, S; Rocha, J; Valente, AA; Silva, CM
our authors
Anabela Tavares Aguiar Valente
Principal Researcher
Carlos Manuel Silva
Associate Professor
Joana Marcelino Pinheiro
PhD Student
João Rocha
Full Professoracknowledgements
The authors are grateful to Doctoral Program EngIQ, Fundacao para a Ciencia e Tecnologia (FCT) and Bosch Thermotechnology for a PhD grant (PD/BDE/113538/2015) to Joana M. Pinheiro. This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement.