JIA Xueying, LIANG Kunfeng, LI Yingying, et al. Crystallization simulation of scraped surface freezer based on coupling model of population balance and multiphase flow[J]. CIESC Journal, 2016, (S2): 128-135.
DOI:
JIA Xueying, LIANG Kunfeng, LI Yingying, et al. Crystallization simulation of scraped surface freezer based on coupling model of population balance and multiphase flow[J]. CIESC Journal, 2016, (S2): 128-135.DOI: 10.11949/j.issn.0438-1157.20161399.
Crystallization simulation of scraped surface freezer based on coupling model of population balance and multiphase flow
By discretizing the population equation into different size groups
a method was established for solving the population balance equation coupled with multiphase flow field.A computational fluid dynamics simulation with population balance model was performed for the scraped surface freezer.The algorithm considering nucleation rate
growth rate
crystal aggregation and breakage was used for describing the water dynamic ice-making crystallization process.By using this model
the key role of crystal aggregation and breakage was reappraised
and the ice crystals number density distributions were obtained in the scraped surface freezer.Then the influence of temperature
scraping speed and the crystallization time on the dynamic crystallization process of the water was studied.The results show that the crystal size distribution would be more centralized and uniform with the crystals aggregation and breakage; if the supercold temperature difference is less than 20℃ and the scraping speed is not more than 10 r·s-1
the crystallization process would be accelerated by reducing the wall temperature or increasing the scraping speed.