摘要
粮层内部通风阻力特性是影响干燥均匀性和能量损耗的关键因素之一。针对传统的经验公式存在精度偏低、未考虑粮层多孔介质的复杂变化因素和非线性的不确定性问题，基于传统的Ergun模型进行了压力损失因素分析；在通风阻力试验平台测定试验数据，通过探索性分析方法对风速进行分段，引入误差影响因子A，导出了一种新的基于多孔介质Ergun的稻谷变层压力场模型；给出了优化阻力特性曲线，构建了变层阻力与层厚的数学关系。试验结果证实，风速小于0．2m／s时，A取值为1；风速在0．2～0．4m／s范围内时，A取值为0．89；风速在0．4～0．6m／s范围内时，λ取值为0．79。
Ventilation resistance characteristic of grain layer is the key influence factor to the drying uniformity and energy consumption, is also the theoretical＇ foundation parameter for layer design and fan selection. The traditional empirical formulas of ventilation resistance of grain layer are low precision and ignore the complicated changes and nonlinear uncertainty problems of grain layer porous media. The pressure loss factors were discussed based on the traditional Ergun model. By testing the airflow resistance on test platform, dividing the air velocity into subsections by the exploratory analysis method, and introducing an error influence factor A, a new pressure field model of variable layer was derived based on the Ergun model. The optimal resistance characteristic curve was given, and the relationship between the ventilation resistance and layer thickness was built. The results show that when the air velocity is less than 0.2 m/s, the λ is 1 ; when the velocity is between 0.2 m/s and 0.4 m/s, the λ is 0. 89 ; and when the velocity is between 0.4 m/s and 0.6 m/s, the λ is 0.79.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2014年第7期216-221,208,共7页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金资助项目(31371871
31071583)
高等学校博士学科点专项科研基金资助项目(20114404110021
20060564003)
