偏高水分稻谷储藏过程中湿热转移规律及结露临界参数  

The law of heat and moisture transfer and critical parameters of condensation during storage of paddy with higher water content

作　　者：张瑞迪 王若兰[1] 渠琛玲[1] 耿宪洲 ZHANG Ruidi;WANG Ruolan;QU Chenling;GENG Xianzhou(College of Food Science and Technology,Henan University of Technology,Zhengzhou 450001,China)

机构地区：[1]河南工业大学粮油食品学院,河南郑州450001

出　　处：《河南工业大学学报（自然科学版）》2020年第4期94-99,共6页Journal of Henan University of Technology：Natural Science Edition

基　　金：“十三五”国家重点研发计划课题“稻谷玉米淀粉代谢及黄变机制”(2016YFD0400104)。

摘　　要：稻谷在储藏过程中因季节交替引起结露现象而发生板结、霉变和虫害,为减少稻谷的质量损失,将水分含量为14.35%±0.48%的偏高水分稻谷置于立方体模拟仓中,设置模拟仓的两个中空仓壁温度分别为0、40℃,模拟季节交替时稻谷储藏所处环境,研究偏高水分稻谷在季节交替时期粮堆内部温度变化规律、水分迁移特点,确定稻谷粮堆结露发生的位置、时间。运用Matlab模拟软件重现了稻谷粮堆温度场分布变化规律。结果表明:偏高水分稻谷在模拟仓内储存期间,粮堆内部和外部之间存在温度差,使得稻谷粮堆内部形成了冷热微气流循环以及倾斜的冷热峰面,粮堆内部的水分随着热气流向低温部位移动,水分集聚于模拟仓低温部位,最终导致粮堆结露现象的发生;偏高水分稻谷在粮堆环境温差40℃储藏48 h后,在粮堆低温部位即模拟仓近冷壁面上层(D’面第1层)发生结露现象,稻谷粮堆结露温度为7℃。研究发现粮食种类、水分含量以及粮堆内外温差等不同,结露临界参数也不同。In the actual storage process of rice,the grain loss resulting from hardening,mildew and insect pest caused by the condensation due to the alternations of seasons occurs frequently.To reduce the grain loss,this experiment was carried out in a cube simulation warehouse,and the higher moisture rice with moisture content of 14.35%±0.48%was put into the cube simulation warehouse.The temperatures of the two hollow wall surfaces in the simulation warehouse were set to 0℃and 40℃respectively,to simulate the environment where the rice was stored during the alternate seasons,so as to study the temperature change and moisture migration characteristics of higher moisture rice,and determine the location and time of dew condensation in rice grains.The Matlab simulation software was used to reproduce the variation law of the temperature field of the grain pile.The experimental results showed that during the storage of the higher moisture rice in the simulation warehouse,there was a temperature difference between the inside and outside of the rice grain pile,the cold and hot micro-air circulation and sloped cold and hot peaks were formed inside the grain pile.Water molecules moved to the low temperature part with the hot air flow,and water gathered in the low temperature part of the simulation bin,which eventually bed to condensation.After the higher moisture rice was stored for 48 hours under the ambient temperature difference of 40℃,the dew condensation occurred at the low temperature part of the grain pile,that is,the upper layer of the cold wall of the simulation warehouse(the first layer of D′surface),and the dew condensation temperature of the rice grain heap was 7℃.The critical parameters of condensation were different because of different grain types,moisture cotent,temperature difference between inside and outside grain pile.

关 键 词：稻谷 结露 湿热转移 临界参数 

分 类 号：TS210.1[轻工技术与工程—粮食、油脂及植物蛋白工程]