气流上升式密集烤房温湿度场分布及其对烟叶质量的影响

Temperature and humidity distributions and their influences on tobacco leaf quality in air ascending bulk curing barn

为明确烟叶烘烤过程烤房的温湿度场分布差异及其对烟叶质量的影响,通过在烤房内均匀放置温湿度传感器采集烘烤过程的环境温湿度数据,从垂直和水平角度分析气流上升式烤房的温湿度分布规律,并研究了烤房不同区位烟叶的烘烤质量差异。结果表明:(1)烤房垂直和水平方向的温湿度均存在显著差异,变黄前期至变黄中期差异较小,变黄后期至定色前期差异增大,定色中期至干筋后期差异减小,且烤房垂直方向的温湿度差异大于水平方向。(2)对烤房烘烤过程的温湿度时序数据进行聚类分析,可将烤房18个区位较好地分为3类,即高温低湿区域、中温中湿区域和低温高湿区域。(3)在鲜烟素质一致的条件下,烤后烟叶样品烘烤损失、上等烟比例、主要化学成分和外观评价得分整体上均没有显著性差异。(4)总糖、还原糖和淀粉含量在垂直方向有上层<中层<下层的趋势,水平方向有前端>中端>后端的趋势,两糖比值分布规律与之相反;垂直方向下层烟叶存在颜色纯正度、柔软度和油润感得分较高的趋势,水平方向中端烟叶存在颜色纯正度、光泽度、柔软度和油润感得分较高的趋势。基于烤房温湿度分布规律研究,有助于为烤房合理分类装烟和烘烤工艺仿真提供数据支撑。

In order to clarify the distributions of temperature and humidity fields during flue-curing in curing barns and its influence on the quality of tobacco leaves,temperature and humidity sensors were uniformly placed in a curing barn to collect the ambient temperature and humidity data during the curing process.The distribution patterns of temperature and humidity in the air ascending curing barn from vertical and horizontal directions were analyzed,and the curing quality difference of tobacco leaves at different locations of the curing barn was studied.The results showed that:1)There were significant differences in temperature and humidity in both vertical and horizontal directions,the difference was small from early yellowing stage to middle yellowing stage;it then increased from late yellowing stage to early color fixing stage and decreased from middle color fixing stage to late stem drying stage.The difference was greater in vertical direction than in horizontal direction.2)According to the cluster analysis of the temperature and humidity time series data of the curing process,18 locations in the barn could be divided into three categories:high temperature and low humidity area,medium temperature and medium humidity area,and low temperature and high humidity area.3)When the quality of the fresh tobacco was the same,there was no significant difference in the total curing loss,percentage of high-grade tobacco leaves,main chemical components,and appearance evaluation score of the cured tobacco samples.4)The contents of total sugar,reducing sugar and starch showed the trend of upper<middle<lower layers in the vertical direction,and the trend of front>middle>back parts in the horizontal direction,however the trends of reducing sugar and total sugar ratio were opposite.The leaves in the lower layer in the vertical direction had higher scores for color purity,softness,and oiliness,while the leaves in the middle part in the horizontal direction had higher scores for color purity,glossiness,softness,and oiliness.The study of temperature and humidity distribution in curing barns provides data to support for proper tobacco leaf classification and loading,as well as simulation of flue curing technology in curing barns.