作　　者： ; ; ; ;

机构地区： 华南理工大学轻工与食品学院

出　　处： 《现代食品科技》 2010年第9期917-920,共4页

摘　　要： 针对食品浸渍冷冻技术中载冷剂选择问题,对以乙醇、丙二醇、氯化钠与水构成四元载冷剂不同组成的粘度与热扩散系数进行分析,计算普朗特(Pr)数,根据Pr数评价不同载冷剂的传热特性。结果表明溶液的组成和温度对热扩散系数和Pr数影响很大。当乙醇、丙二醇与氯化钠的含量增加,热扩散系数先减小后增加,且随着温度的下降而减小。当浸渍冻结工作温度为-20、-30与-40℃时,普朗特数最小的溶液为:乙醇20%,丙二醇14%,氯化钠4%的水溶液、乙醇20%,丙二醇21%,氯化钠4%的水溶液与乙醇20%,丙二醇30%,氯化钠4%的水溶液。 A multicomponent refrigerant liquid was made of ethanol,propylene glycol,sodium chloride and water in immersion chilling and freezing（ICF）.The viscosity and thermal diffusion coefficient of refrigerant liquid with different composition were studied,and its heat transfer properties were evaluated by the Prandtl number（Pr）.Results indicated that the solution composition and temperature had significant influences on thermal diffusion coefficient and Pr.Thermal diffusion coefficient increased at first and then decreased with the increase of contents of ethanol,propylene glycol,or sodium chloride,while it decreased with the temperature decreasing.The proportion of three components（ethanol-propylene glycol-sodium chloride） of refrigerant liquid with the smallest Pr for ICF at-20,-30,and-40 ℃ were 20/14/4,20/21/4,and 20/30/4,respectively.

关 键 词： 浸渍冷冻 多元载冷剂 热扩散系数 普朗特数 传热

领　　域： [一般工业技术]