预测平房仓中小麦的密度分布与储藏质量模型

采用LHT-1粮食回弹模量仪测定小麦堆在不同压应力下的压缩密度,实验结果表明：当小麦(众麦1号,含水率为11.70.-18.18 %w.b.)的竖直压应力增大(0.631-221.060 kPa)压缩密度增大(740.50-853.85 kg/m₃),两者可拟合出二次关系方程。建立平房仓中小麦的密度、应力与粮层深度关系的微分方程组,用数值方法计算平房仓中小麦密度与粮层深度关系,由积分法计算出平房仓中小麦的储藏重量。模型计算结果表明：平房仓中小麦密度随着粮层深度的增加而增大,随着深度增加,密度增加率减小；在一个20米宽,40米长的平房仓中,小麦密度从表层的800 kg/m₃增加到10米深处的833.5 kg/m₃,密度增加了4.1%。在同一深处,密度随平房仓长、宽的尺寸增大而增大,增大值很小。在平房仓中同一深处,密度随含水率的增大而增大,增大值很小。小麦的摩擦角、小麦与仓壁摩擦系数几乎不影响平房仓中的密度。本模型计算了5个实仓中的小麦储藏重量,计算值与粮重实际账面数几乎一致,最大误差为2.63%。

A Prediction Model of Density Distribution and Storage Weight of

The LHT-1 rebound modulus tester was used to determine the compression density of wheat under different top pressures. The results of experiment show that as the average vertical stress of wheat, Zhongmai No. 1, increased from 0.631 to 221.060 kPa, the compression density of wheat increased from 740.50 to 853.85 kg/m₃ in the moisture range of 11.70.-18.18 %w.b. The compression densities of wheat heap exhibited a quadratic relationship with average vertical stress. A differential equation group of relationship of density, pressure and depth in a horziontal warehouse was derived. Numerical method was used to obtain the relationship of density, pressure and depth in a horziontal warehouse and then the storage weight of wheat was calculated by integration. The results of calculation of this model show that density of wheat in a horziontal warehouse increased with the wheat depth, and rate of increase of density of wheat decreased with the depth. In a 20 meter wide, 40 meter long horziontal warehouse, as depth of wheat increase from 0 to10 m, density of wheat decreased from 800 to 833.5 kg/m₃, density increased by 4.1%. At the same depth, the density increases with the size of the length and the width of the horziontal warehouse, and the increase is very small. At the same depth, the density increases with the increase of moisture, and the increase is small. The friction angle of wheat and the friction coefficient of the wheat and wall are almost no influence on the density of wheat in the horziontal warehouse. This model calculated the storage weight of wheat in 5 horziontal warehouse, and the calculated value was almost the same as the actual book number weight of wheat, and the maximum error was 2.63%.