Characteristics of Multiple-Pass Heat Exchanger with Melting of Falling Snow

The structure of a multiple-pass heat exchanger composed of pipes and plate fins is similar to that of heat exchangers used for melting snow. In this study, we investigated the characteristics of a multiple-pass heat exchanger having two types, a regular pitch type and an irregular one, focusing on the brine pipe pitch of the multiple-pass heat exchanger. The perfect melting condition and the melting efficiency were related to the dimensionless parameters of the heat exchanger and its operating conditions. The calculated results for the perfect melting condition and the melting efficiency agreed with the results obtained from field tests on melting of falling snow. Applying the irregular pitch extends the critical condition for perfect melting when the flow rate of brine is low or the area for melting of falling snow is large. Also, the melting efficiency of the irregular pitch is higher than that of the regular pitch.