An experimental study on edge-affected frosting characteristics on a vertical cold plate at different surface temperatures

•Edge effect on droplet condensation and frosting characteristics are presented.•Frosting process on vertical cold plate is studied under forced convection.•Size and distribution of droplets are greatly affected by surface temperature.•Frost layer thickness is significantly affected by surface temperature. Frosting has received significant attention in various fields due to its potential threat. To accurately predict and control the frosting process on vertical cold plate surface considering the edge effect, the frosting characteristics with surface temperature between -15.0 °C and -5.0 °C are experimentally studied under forced convection. The results show that as the cold plate temperature decreases, the durations of droplet solidification stage in the edge-affected region decreases slowly. Meanwhile, the area-average equivalent contact diameter and the coverage area ratio of edge-affected droplets both increases. And the density difference of droplet distribution between the edge-affected and unaffected regions increases from 1.02 × 107 to 3.58 × 108 per m2. The average frost layer thickness reaches 7.41 × 10-4 m for -7.5 °C at 2,400 s, and it increases by 21.20%, 38.40%, and 82.08% when the temperature decreases to -10.0 °C, -12.5 °C, and -15.0 °C, respectively. Results of this study are expected to be meaningful for the optimization of frost detection and defrosting technologies.