Local heat flux measurement in an ice thermal storage capsule pack using magnetic resonance imaging
Anew method to measure local heat flux distribution at capsule surfaces in an ice thermal storage capsule pack using magnetic resonance imaging (MRI) was developed to investigate the effect of non-uniform flow on the heat transfer in the storage vessel. In this method, local heat flux distribution at a capsule was calculated from the time-evolution of water-ice interface positions in the capsule when water enclosed the capsule was frozen by coolant. The mean heat flux at the single capsule surface under uniform flow obtained by this method agrees with
one by the conventional method. By applying this method to a pack of spherical ice capsules, local heat flux
distributions on capsule surfaces were measured, and axial velocity distribution of coolant through the pack were
obtained by the phase method in MRI techniques. Based on these results, the heat exchange effectiveness depends on channel flow of coolant as the effect of non-uniform flow on the heat transfer in the pack was discussed.