谷物湿热平衡新模型及热力学特性的研究

Heat and Moisture Balance New Model and Thermodynamic Properties of Grain

建立谷物平衡水分与相对湿度在不同温度下的关系模型,并利用小麦、玉米、水稻、大米的静态平衡试验数据进行拟合。结果表明,该方程适合描述小麦、玉米、水稻、大米的等温线,可直接求解出谷物的平衡水分。另外,根据所建立的模型,预测了不同温度条件下的安全储藏水分,并对谷物的热力学性能进行了分析:吸着等热值随着平衡水分值的减小而增加,解吸等热值增加更为显著;解吸和吸附过程中吸着等热值均高于水汽化潜热;平衡水分大于25%后,吸着等热值趋于稳定,与汽化潜热值接近;根据分析所得数据,拟合了小麦、稻谷、玉米解吸与吸附过程的吸着等热曲线回归方程,为以能量化的观念实施粮仓作业管理,实现高效、合理、节能储粮提供了有利依据。

The equilibrium moisture content and equilibrium relative humidity models of grain are established under different temperatures. The static equilibrium test data of wheat,corn,rough rice and rice are fitted. The fitting results indicate that the model has high precision to describe the isotherm equations of grain and could calculate the equilibrium moisture content directly. In addition,the established model predicates the safe moistures under different temperatures and analyzes the thermodynamic properties of grains,which indicates that the isosteric of sorption heat increases with the decrease of grain equilibrium moisture,especially the increase of isosteric of desorption heat;isosteric of sorption heat is higher than latent heat of vaporization during desorption and sorption heat process; After the equilibrium moisture content reached 25%（ w. b.）,the isosteric of sorption heat regression equations is to be stable and approaches latent heat of vaporization. Based on the data analysis,sorption isosteric heat curvilinear regression regression equations of wheat,rice and maize are fitted,providing an available basis for the granary energy job management and the efficient reasonable energy- saving ventilation.