基于绝对水势图的储粮通风作业管理初探  

The Moisture Migration of Heat and Humidity Grain Bulk and Granary Aeration Management

作　　者：吴文福[1] 陈思羽[1,2] 韩峰[1] 张亚秋[1] 张忠杰[3] 吴子丹 

机构地区：[1]吉林大学生物与农业工程学院,长春130022 [2]佳木斯大学机械工程学院,佳木斯154007 [3]国家粮食局科学研究院,北京100037

出　　处：《中国粮油学报》2017年第11期100-107,共8页Journal of the Chinese Cereals and Oils Association

基　　金："十三五"国家重点研发计划(2017YFD0401 003-01)

摘　　要：基于吉布斯自由能及热力学第一、二定律,深入分析粮食仓储过程中粮食籽粒及空气的水分迁移,建立了粮食籽粒和空气的绝对水势计算模型,解析基于能量场的湿热粮堆通风条件。以小麦为例,绘制初始温度为20℃,含水量为14.5%(w.b.)的小麦绝对水势图,建立了基于绝对水势能的小麦机械通风窗口,通过判断空气当前状态点处在小麦通风窗口的位置,快速准确的判断粮食是否需要进行调质、降温或降水通风作业。在小型储粮仓的通风试验中,试验开始时空气绝对湿度10.24 mm Hg,绝对水势能981.99 k J/kg,粮食绝对湿度14.44 mm Hg,绝对水势能1 040.56 k J/kg,系统判断并执行降水通风。通风结束后粮食的绝对水势能由最初1 040.56 k J/kg降到994.16 k J/kg,预测仓内平均降水0.5%,实际降水0.49%,满足实际要求。利用谷物与空气的绝对水势能进行通风判断和图形化管理机械通风作业,相比于原始低效的温、湿度处理方法,此图形化管理能时时反映粮食与空气的当前状态,快速准确的进行通风判断,减少无效和低效通风,降低了能耗,提高了工作效率。Aeration system was used to reduce the deterioration of stored grain by cooling the grain reached a safe temperature. Grain in storage was subject to moisture migration caused by differences in grain temperature. In order to explore the quality and heat transfer characteristics of grain and surrounding environment, moisture migration between grain and air was analyzed based on the Gibbs free energy and the first and second law of thermodynamics. The absolute water potential models of grain and air were built by the energy field analysis. Result showed that when the total energy was equal to the energy consumption of grain internal migration, the water content of grain and air kept each other in balance; when less than the energy consumption of grain internal migration, the grain internal binding energy decreased and the air moisture transferred to the surface of grain in the adsorption state; when more than the energy consumption of grain internal migration, the water molecules broke away from the bondage of locus by obtaining the energy through the environment and the water content of grain transferred to the air from the surface of grain in the desorption state. According to the grain aeration management standards, the absolute water potential diagram was adopted to improve the aeration management by the analysis of aeration condition based on the energy field, which provided theoretical foundation for the energy analysis of grain heat and humidity control. With wheat, for ex- ample, the cooling window, the precipitation window and the tempering window were built in the absolute water potential diagram and aeration system controlled the aeration operation after judging the current atmosphere position in the aeration window of absolute water potential diagram. In the decreasing water experiment, temperature and humidi- ty were received by the capture system and aeration system was managed by calculating and comparing the absolute water potential of air and grain. At the beginning of the experiment , the air abso

关 键 词：粮食仓储 通风 绝对水势 湿热调控 

分 类 号：S379[农业科学—农产品加工]