Characteristics of vertical mantle heat exchangers for solar water heaters

The Row structure in vertical mantle heat exchangers was investigated using a full-scale tank designed to Facilitate now visualisation. The Row struct ure and velocities in the mantle were measured using a particle Image Veloc imetry (PIV) system. A CFD simulation model of vertical mantle heat exchang ers was also developed For detailed evaluation of the heat flux distributio n over the mantle surface. Both the experimental and simulation results ind icate that distribution of the flow around the mantle gap is governed by bu oyancy driven recirculation in the mantle. The operation of the mantle was evaluated for both high and low temperature input Rows. (C) 2000 Elsevier S cience Ltd. All rights reserved.