Development of High Quality Grin Drying Method using Solar Battery Ventilation and Solar Desiccant System

本研究的目的是设计一种新的太阳能干燥剂干燥方法，以节省粮食干燥过程中的能源，并利用常温低湿空气进行高质量粮食干燥。我们开发了一种太阳能干燥剂干燥系统，它通过干燥干燥剂来储存太阳能，并将储存的能量用于夜间或阴天或雨天的粮食干燥。在一栋温室里安装了一台用于干燥稻谷和干燥剂的固定式床干燥机。温室附近安装了4块129W*4=516W的太阳能电池板。所产生的电能用于驱动通风风扇和交替改变气流方向的烘干鼓风机。测量太阳辐射、温度和湿度，并传输到计算机。通过计算和比较温室内外的平衡含水率来控制通风风扇，以保持室内空气的低湿度。我们在1995年和1996年秋季对太阳能干燥系统进行了测试。晴天收获高水分粮食，白天利用太阳热能将其干燥到水分水平进行短期储存，晚上或下一个阴天用干燥剂干燥成长期储存的谷物。在阴天，收获的粮食通过干燥剂和太阳热干燥到水分水平，以便短期储存。实验证明，即使在阴雨天，用与粮食和天然能源相同的沸石用量的太阳能干燥剂干燥系统，也能将收获的稻谷干燥到短期或长期储藏的含水率水平。

The object of this study is to devise a new solar desiccant drying method for energy savings in grain drying process and high quality grain drying using method using low humid air at ordinary temperature. We developed a solar desiccant drying system, which stores solar energy by drying the desiccant and uses the stored energy for grain drying at night or cloudy or rainy day. A stationary bed dryer for drying paddy and desiccant was installed in a green house. Artificial zeolite which is made from coal ash waste is used for desiccant, and four solar cell plates (129w*4=516W) were installed near the green house. The generated electric power is used for driving ventilation fans and a drying blower which changes the air flow direction alternately. Solar radiation, temperature and humidity were measured and transferred to computer. The ventilation fans were controlled by calculating and comparing both the equilibrium moisture content of inside and outside the green house to maintain the inside air at low humidity.We tested the solar drying system in autumn 1995 and 1996. On sunny day, harvested high moisture grain dried into the moisture level for short term storage by solar heat in the daytime, and dried into that for long term storage by desiccant at night or next cloudy day. On cloudy day, the harvested grain dried into the moisture level for short term storage by both desiccant and solar heat. It was proved that the harvested paddy can be dried into the moisture level for the short or long term storage even on a cloudy or rainy day by the solar desiccant drying system using the same amount of zeolite as that of grain and natural energy.