Measurement and augmentation of effective thermal conductivity of La0.8Ce0.2Ni5 hydride bed

Measurement and the improvement of effective thermal conductivity for a metal hydride bed – a review

“…The heat source was provided by a miniature sheath heater in the center of the chamber, indium was coated on the heater and thermocouples to reduce the contact thermal resistance. In 2017, Madaria et al 33 designed a thermal conductivity test cell using the radial absolute method to measure the effective thermal conductivity of different forms of La 0.8 Ce 0.2 Ni 5 beds, as shown in Fig. 4 .…”

“…However, Ishido et al 7 found that the effective thermal conductivity of Mg and Mg/10 wt% Ni hydride powder increased with increasing temperature. Madaria et al 33 found that the effective thermal conductivity of La 0.8 Ce 0.2 Ni 5 powder and the compact with graphite flakes were hardly affected by temperature at 5 MPa hydrogen pressure, but when the hydrogen pressure was reduced to 1 MPa, the effective thermal conductivity decreased slightly with increasing temperature. Popilevsky et al 34 determined that the effective thermal conductivity of MgH 2 containing 8–9.5 vol% Mg decreased from 23 to 13 W (m −1 K −1 ) when the temperature increased from 300 to 525 K. Wang et al 35 measured that the effective thermal conductivity of YbH 1.88 decreased from 6.2 to 3.9 W (m −1 K −1 ) when the temperature increased from 298 K to 413 K. They believed that it might due to the increase of dislocation density in the specimen after hydrogen absorption.…”

State of the Art in Development of Heat Exchanger Geometry Optimization and Different Storage Bed Designs of a Metal Hydride Reactor

“…Madaria Y. and Kumar E. A. [ 68 ] showed that the maximum values of effective thermal conductivity increased to 4.7 W/(mK) for a compact with graphite flakes and up to 6.8 W/(mK) for a compact with graphite and copper wire, which is four to six times higher than for a loosely packed La 0.8 Ce 0.2 Ni 5 powder (1.3 W/(mK). Delhomme B. et al [ 69 ] proposed a method for improving heat transfer in large Mg/MgH 2 storage metal hydride reactors by creating metal hydride/ENG compacts.…”