横向与竖向通风玉米粮层阻力研究

Research on Influence of Horizontal and Vertical Ventilation on the Grain Resistance of Corns

利用180 t模拟试验仓测试了横向、下行吸出式、上行压入式竖向通风的玉米粮堆的粮层阻力。结果表明:在0.021~0.06 m^3/(s·m^2)的单位面积通风量之间,横向通风单位粮层阻力为9.74~28.95 Pa/m,两者关系模型为Y=528x1.032 2(R2=0.998 2),或,Y=-954.15x2+561.78x-1.648(R2=0.999 2)。在0.004 5~0.089 5 m3/(s·m^2)的单位面积通风量之间,下行吸出式竖向通风单位粮层阻力为4.0~85.0 Pa/m;上行压入式竖向通风单位粮层阻力为3.8~70 Pa/m,两者关系模型与横向相近,但系数远大于横向。比较发现:横向通风玉米单位粮层阻力最小,比竖向通风小一倍左右,表明由玉米粮粒组成的多孔介质堆具有各向异性的特点;下行吸出式竖向通风的粮层阻力稍大于上行压入式的粮层阻力;研究结果进一步完善了储粮通风理论,储粮通风系统工程设计和建设方面具有实际应用价值。

The resistance of grain layer was measured for the corn mass in vertical ventilation （VV） with hori- zontal ventilation （HV）, downward suction （DS） and upward pressing （UP）. The results indicated that the unit grain layer resistance （UGLR） in the horizontal ventilation was 9.74 - 28.95 Pa/m between 0.021 to 0.06 m3/（ s·m^2 ） of air flow sensor （AFS）. And UGLR and AFS had the relationship models of Y = 528x1.0322 （R^2 = 0. 998 2） or Y = -954.15x^2 ＋561.78x -1.648 （R^2 =0.999 2）. In HV. UGLR of DS and UP of VV were 4.0-85.0 Pa/m and 3.8-70 Pa/m between 0. 004 5 and 0. 089 5 m3/（ S·m^2） of AFS, respectively. The relationship models of UGLR and AFS in DS and UP of VV were similar to the horizontal model, but the coefficient of them was more than the hori- zontal model. By comparing, UGLR of HV was the minimum one, which was less one time than UGLR of VV. The porous media mass of corn composed by grains had a characteristic of anisotropy; UGLR of DS was slightly higher than that of UP. The results further perfected the theory of ventilation for stored grains which had practical applications in design and building of ventilation system for stored grains.