加压冷冻白条肉气体介质的热质传输特性分析

Analysis of heat and mass transfer characteristics of gases for pressure freezing carcass

加压冷冻法可以用来降低白条肉的干耗,对在加压冻结工艺下的两种冻结介质(氮气与空气)的热质传输过程进行分析,建立了白条肉加压冷冻过程的耦合传热传质模型,给出了表面传热系数、对流传质系数的计算关联式.研究发现,随着介质压力增大强制对流表面传热系数明显增大,但强制对流传质系数明显减小.在相同的压力条件下,氮气和空气的表面传热系数和对流传质系数相差不大.

Pressure freezing method can be used to reduce the weight loss of carcass.In this paper,the heat and mass transfer processes of two freezing media(nitrogen and air)were analyzed under pressure freezing process.A coupled heat and mass transfer model of pressure freezing process was established for carcass,and the calculation correlations of convective heat transfer coefficient and convective mass transfer coefficient were given.It was found that the forced convection heat transfer coefficient increases significantly with the increase of the medium pressure,but the forced convection mass transfer coefficient decreased significantly.The convective heat transfer coefficient and convective mass transfer coefficient of nitrogen and air had little difference under the same pressure.