空气流动方式影响种子热泵干燥均匀性的研究

Effect of Airflow Types on Moisture Uniformity of Seed Heat Pump Drying

干燥不均匀性研究对于热泵干燥装置的设计与应用具有重要的意义.本文以白菜种子热泵干燥为研究对象,采用数值模拟和统计分析方法,分析了干燥空气从干燥托盘左上角流入右上角流出、中间上部流入下部流出、左上角流入右下角流出、左侧流入右侧流出等4种流动方式对热泵干燥不均匀性的影响.结果表明,干燥空气中间上部流入下部流出方式的干燥速率较低,干燥后种子的不均匀性最明显,而干燥空气左上角流入右下角流出方式的干燥速率较高,干燥后种子的均匀性最好,在热泵干燥装置设计中应优先采用该种流动方式.

The moisture uniformity of dried products is important for design and application of heat pump dryers.The cabbage seeds drying by heat pump drying are investigated. The simulation method and statistic analysis are used to study the effect of airflow types on the moisture uniformity of heat pump drying. Four types of airflows,including the top left inflow and top right outflow,the top middle inflow and bottom middle outflow,the top left inflow and lower right outflow,and the left inflow and right outflow,are put forward. The results show that,among the four airflow types,the airflow of top middle inflow and bottom middle outflow has the lowest drying rate and poorest moisture uniformity,while the airflow of top left inflow and bottom right outflow has high drying rate and good moisture uniformity. Therefore,the airflow of top left inflow and bottom right outflow should be preferentially adopted in the design of heat pump dryers.