升华干燥过程的损失分析  

Exergy Loss Analysis on Freeze-drying

作　　者：刘永忠[1] 陈三强[1] 冯霄[1] 

机构地区：[1]西安交通大学环境与化学工程学院,陕西西安710049

出　　处：《高校化学工程学报》2003年第6期637-642,共6页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金资助项目(20206026);西安交通大学科学研究基金资助项目。

摘　　要：通过对物料在升华干燥过程中的损失分析, 建立了升华干燥过程的损失分析模型。结合升华干燥动力学模型和损失分析模型,以牛肉为冷冻干燥过程的模型物料,计算了物料表面加热温度、干燥室压力和物料厚度等操作条件的变化对升华干燥过程损失的影响。计算结果表明:随着干燥室压力的增大,物料的损失减小;随着物料表面加热温度的降低,损失减小;随着物料厚度的减小,损失逐渐减小;在冷冻干燥过程中,损失主要集中在升华干燥阶段,在解析干燥阶段,物料表面加热温度的升高不会引起损失的大幅度增加。In order to interpret energy degrading during freeze-drying, exergy balance analysis on the differential control volume in dried layer was conducted, and a mathematical model of exergy loss for the primary drying was proposed. Taken bovine muscle for example, the influence of operation conditions, such as surface temperature of the material being dried, chamber pressure and thickness of slab, was analyzed based on the drying dynamic model and the exergy loss model. The results indicate that the exergy loss reduces with the chamber pressure rising during the primary drying period; the exergy loss reduces when the surface temperature decreases or when the thickness of slab is reduced. The exergy loss in the primary drying period plays important part in quantity during the whole freeze-drying period. In addition, the exergy loss in the secondary drying period will not increase sharply while the surface temperature arises. For shortening drying time period and reducing exergy loss during drying, an optimal surface temperature in different drying periods is obtained respectively.

关 键 词：升华干燥 YONG损失 数学模型 操作条件 

分 类 号：TQ028.63[化学工程] TQ026.6