Biomethane is produced by removing undesirable components such as water vapor, carbon dioxide and other pollutants in a biogas upgrading process. Frosting the water vapor contained in the biogas is one of the dehydration processes used in a biogas upgrading process. In order to simulate a frost layer on a cold plate, many models have been developed. These models are valid for a limited temperature range. In this study, heat and mass transfer equations were used in a numerical approach to model the frost growth and its densification on the external side of a fin-and-tube heat exchanger. The model used in this study is valid for low temperatures from 0[Formula: see text]C to [Formula: see text]C and lower. The evaporation process of temperature glide refrigerants is also modeled from [Formula: see text]C to [Formula: see text]C. The results show a decreased heat transfer rate during frost mass growth on fins and rows. During its growth, frost layer thermal conductivity is relatively low leading to decrease the heat exchanger performance. On the other hand, frost layer thickness increases the external surface blockage, leading to higher pressure drop on the external side. This model has been validated by comparing numerical and experimental results for the biogas outlet temperature.
2D Frost Growth and Densification Model in Counterflow
Heat Exchanger