南亚热带地区稻谷立筒仓智能化降温通风试验

在广州市南沙区于2018年1月16日～2月7日期间,对装粮高度11 m的稻谷立筒仓(约650 t)采用自然冷空气进行智能化降温通风,分别采用5.5 kW和2.2 kW的离心风机上行式通风,风机运转条件是粮堆与大气温度之差≥3℃,粮堆平衡绝对湿度(EAHg)≦大气平衡绝对湿度(AHa)。结果表明,风机自动化运行时间主要在夜间,采用5.5 kW风机的301号仓粮堆平均温度由19.2℃降到13.8℃,风机运转了72.9h,单位能耗是0.087 kW·h t~(-1)℃~(-1);采用2.2 kW风机的501号仓粮堆平均温度由20.9℃降到12.4℃,风机运转了148.6 h,单位能耗是0.047 kW h t~(-1)℃~(-1),与当地人工控制的吸出式下行降温通风单位能耗比较,显著节约电能54%～75%。两个智能化降温通风仓通风结束后粮堆水分保持不变。与对照仓比较,采用低功率离心风机进行智能化降温通风后的稻谷出米率和加工品质有提高的趋势。这说明稻谷立筒仓智能化通风期间整个粮堆湿热分布均匀,不发生水分迁移。

Lowering Paddy Temperature in a Steel-concrete Silo with Intellectualized Mechanical Aeration Guided by the CAE Equation

Combined the intelligent detection technology with ventilation window control model, the ventilation window region for lowering grain temperature was constructed according to the principle of controlling aeration by paddy CAE equation,the absolute humidity adsorption equilibrium curve of paddy and atmospheric saturated humidity curve. The ventilator was turned on when the air status point within the window region, turned off when outside. During January 11th to Feburary 7th, 2018, the system was used for two steel-concrete silos of 650 t paddy in Guangzhou Lingnan Spike Grain Cereals Co. Ltd. The ventilators was mostly turned on at night time.The one silos was decreased grain temperature of 5.4°C within the accumulated 72.9 h of ventilator running and unit energy consumption of 0.087 kW h t-1°C -1 with one 5.5 kW-power centrifugal blower. The other silo was decreased grain temperature of 8.5°C within the accumulated 148.6 h of ventilator running and unit energy consumption of 0.047 kW h t-1°C -1 with one 2.2 kW-power centrifugal blower. These unit energy consumption was much lower 54%~75% than that (0.127 kW h t-1°C -1) of the local general temperature-decreasing aeration with the manual controlling downward suction ventilation. The control silo was decreased grain temperature of 2.1°C within the accumulated 40 h of ventilator running and unit energy consumption of 0.351 kW h t-1°C -1with one 15 kW-power centrifugal blower and manual controlling upward forced ventilation. Compared to the paddy in the control silo, the total milled rice yield and grain quality in steel-concrete silos was slightly improved by the intellectualized mechanical aeration and lower power centrifugal blower, and the moisture content of paddy remained unchanged. These results suggest that the humidity and heat in paddy bulk of steel-concrete silos was well evenly distributed during intellectualized aeration.