制冷学报2017，Vol.38Issue(2)：76-81,6.DOI:10.3969/j.issn.0253-4339.2017.02.076
降压过程对过冷水成核影响的理论和实验研究
Theoretical and Experimental Study on the Effects of Depressurization Process on the Ice Nucleation of Supercooled Water
摘要
Abstract
The control of ice nucleation temperature during the freezing stage has significant influences on quality uniformity of freeze dried products and drying rate of later stages.For active depressurization to induce ice nucleation of supercooled water in vials,the effects of depressurization rate,final pressure level and supercooling degree on the nucleation phenomenon were studied experimentally and theoretically here.The following results were obtained:under atmospheric pressure the range of releasing supercooling degree(RSD) was 9-17 ℃,while during depressurization the range of RSD became 8-11 ℃;in the range of 5-20 kPa/s the depressurization rate had little effect on the nucleation of supercooled water;in the range of 100-400 Pa,lower final pressure led to lower RSD.Through numerical calculation and analysis it was indicated that the lowest temperature of surface water during depressurization maybe the key factor influencing ice nucleation.关键词
冷冻干燥/预冻/成核/降压/过冷水Key words
freeze drying/pre-freezing/nucleation/depressurization/supercooled water分类
通用工业技术引用本文复制引用
黄根生,陈光明,张绍志,蒋青..降压过程对过冷水成核影响的理论和实验研究[J].制冷学报,2017,38(2):76-81,6.基金项目
本文受浙江省文物局文物保护科技项目(2013007)资助.(The project was supported by Archaeological Artifact Protection Technology Project of Zhejiang Province(No.2013007).) （2013007）
