大米和大豆CAE方程及平衡绝对曲线图研究

Study on CAE Model and the Curve Graphs of Equilibrium Absolute Humidity of Rice and Soybean

在RH 11%～96%和不同温度(10、20、25、30和35℃)下采用静态称重法测定了11个大米品种和10个大豆品种的水分吸着等温线,并采用CAE方程进行拟合。对大米样品,决定系数(R2)>0.991 1,平均相对百分率误差(MRE)<5.048%;对大豆样品R2>0.977 7,MRE<10.778%。CAE方程参数在大米品种之间或大豆品种之间差异不明显。吸附方程参数与解吸方程参数之间差异大,表明存在吸着滞后现象。推导的大米和大豆CAE解吸、吸附方程用于绘制平衡绝对湿度曲线图。应根据不同粮食种类,通风操作中使用不同CAE方程,但不必考虑同一种类粮食的不同品种的影响;根据不同通风目的分开使用解吸CAE方程和吸附CAE方程。通过曲线图或软件查阅粮堆和大气的平衡绝对湿度值和露点温度,可以快速确定储粮是否应该进行通风操作。

The moisture sorption isotherms of milled rice and soybean respectively from eleven and ten varieties were determined under RH 11%-96% and different temperature （10,20,25,30 and 35 ℃ ） conditions and were fitted by CAE equation. For milled rice ,the determination coefficient （RE） 〉 0. 991 1, and mean relative percentage error （MRE） 〈 5. 048 %. For soybean, R2 〉 0. 977 7, MRE 〈 10.778%. As well as for soybean, the parameters in CAE model for both milled rice desorption and adsorption isotherms showed appreciable difference, consistent with a hysteresis between desorption and adsorption behavior at lower ERH. The deduced CAE models for both desorption and adsorption of milled rice or soybean were respectively used to make curve graphs for searching equilibrium absolute humidity of the grain with particular moisture at certain temperature. To the purpose of decreasing grain temperature or moisture content, or increasing grain moisture content, one can choose the curve graph for equilibrium absolute humidity of the desorption or adsorption, and quickly make decision on grain aeration operation in a depot after referring to the absolute humidity of atmosphere at that particular RH and temperature.