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ISSN Online: 2379-1748

ISBN Flash Drive: 978-1-56700-483-0

ISBN Online: 978-1-56700-482-3

4th Thermal and Fluids Engineering Conference
April, 14–17, 2019 , Las Vegas, NV, USA

A NEW HYBRID HEAT STORAGE FIXED BED: PROOF OF CONCEPT

Get access (open in a dialog) pages 1735-1739
DOI: 10.1615/TFEC2019.tes.027960

Abstract

This work is devoted to the numerical studies of a new heat storage fixed bed reactor consisting two sort of particles: metal spherical particles and metal spheres containing a phase change material (PCM, paraffin). The main advantage of combination of both sorts of particles is more flexible control of the overall time for the heat charge and discharge of the whole fixed bed. In particular, the advantage of metal particles is that they conduct and absorb heat quickly, which helps to control/regulate the overall heat transfer rate and response time. The metal selected is aluminum, which is a great conductor, a relatively good heat capacitor, corrosion resistant, lightweight, and reasonably cheap. Water is used as the medium that carries thermal energy from the heat source to the PCM. A new interparticle discrete-element-method model, which takes into account the interparticle, particle-liquid heat transfer and phase change processes inside each PCM-capsule, was developed and validated against experimental data published in the literature. The simulations were conducted for two sets of comparisons. One compares the performance of heat storage units with different volume fractions of aluminum particles, but identical apparent size, while the other set compares the performance of heat storage units with different volume fractions of aluminum particles but identical number of encapsulated PCM particles. Numerical simulations using our new model show that the increase in heat transfer is achieved by changing volume fraction of aluminum particles in the fixed bed. To reduce the charging/discharging time by 10%, the heat capacity per volume should be reduced by 20%.