靜置式厚層玉米種子干燥之模糊控制

Fixed Deep-Bed Drying of Seed Corn Using Fuzzy Control

邱士益(Shih-I Chiou) ； 方煒(Wei Fang)

《農業機械學刊》 5卷3期 (1996/09) Pp. 1-16

https://doi.org/10.30062/JAM.199609.0001

摘要

本省每年在台中種苗改良繁殖場之玉米種子乾燥作業量可達到千噸之多，玉米穗或粒以靜置式厚層方式堆積在大型的水泥乾燥倉中，乾燥方式爲由下向上的單向熱風乾燥，控制方式採人工設定熱風之上限溫度。現階段此乾燥系統作業中有待改善之部分包括：(1)、乾燥不均勻，尤其是熱風入口之底層榖物常有過乾現象，不利於榖物之品質，影響種子發芽率。(2)、熱風溫度僅以人爲方式設定上限，未能因應大氣及榖物狀況作適當調整，是以既費工且耗油，能源利用效率低，使得作業成本居高不下。
本研究嘗試將模糊控制技術與傳統的限溫乾燥方式結合，於民國83年7月至民國84年3月，使用台中種苗改良繁殖場整廠之大型靜置式乾燥倉，進行實驗以驗證模糊控制乾燥之可行性。分析試驗之結果可得到以下幾項結論：(1)、模糊多段控制可應用於大型之靜置式厚層乾燥倉，在乾燥過程中可隨大所氣及榖物狀況而自動調整熱風溫度，達到自動控制之日的。(2)、在玉米穗乾燥方面，每倉在3~5日的乾燥作業下平均耗油量約爲1000公昇使用模糊多段控制在夏季時約可節省燃油70公昇，耗油成本降低7%；冬季時約可節省120公昇燃油，耗成本可降低12%。(3)、模糊控制乾燥對榖物之乾燥品質有較好之影響。由種子檢查報告可知，使用模糊多段控制策略乾燥之玉米種子其發芽率爲95~98%，比使用傳統單段限溫乾燥方式乾燥之玉米種子發芽率(91~97%)爲高，且各倉間之差異也較小（前者3%，後者6%）。

關鍵字

靜置式厚層干燥 ； 玉米 ； 模糊控制

並列摘要

More than a thousand tons of corn seeds need to be dried in Taiwan Seed Service, annually. The drying process is conducted in a large cement building with 33 stationary compartments. Ear or shelled corns are stacked in each compartment to form a deep-bed and blown with heated air from the bottom of the bed. The only mean in controlling the temperature of the heated air is to set the upper limit manually. The drying system described above has many drawbacks, such as: (1) uniformity of the moisture content of the corns is difficult to keep. Corns at the bottom layer of the bed are normally too dry which reduce the quality of the corn seeds. (2) the control of the heated air temperature is by setting its upper bound alone, which neglects the influence of the environmental conditions and the current status of the moisture content of the corn. The consequences are high fuel consumption and low thermal efficiency, which lead to high operating cost.
This study combines the fuzzy control technique with the conventional heated-air-temperature-limiting drying method to improve the drying efficiency and the quality of the dried seeds. The experiments were conducted in Taiwan Seed Service during the period from July, 1994 to March, 1995. The results are: (1) fuzzy control can be applied to improve the conventional drying control. The limiting-heated-air-temperature can be set automatically by the fuzzy control rules in response to the variations of the changing environment and grain conditions. (2) in ear-corn drying, the fuel consumption of a drying compartment in a 3 to 5 day drying period is about 1000 liters. With the help of the fuzzy control, the saving of the fuel can be as high as 70 liters (7%) in summer and an average of 120 liters (12%) in winter throughout experiments. (3) the fuzzy control provides better quality of the dried seeds. The germinant rate of the fuzzy controlled dried seeds are ranged between 95 to 98% which is better than 91 to 97%, the germinant rate of the seeds dried using conventional method. The variations of the quality among drying compartments using fuzzy control is also smaller than the conventional method (3% vs. 6%).

並列關鍵字

Fixed deep-bed drying ； Corn ； Fuzzy control