环形通风地槽对实际温度场特征的适应性研究

Adaptability of Loop-Duct Mechanical Aeration to Actual Temperature Pattern In Grain Storage

通风地槽的形式对粮仓机械通风的效率和均匀性等设计指标具有重要作用。常规通风地槽是以沿风道均匀出风作为设计思想,但在实践中难以有效解决通风死角的问题。实际粮温的分布受仓房热传导特性和粮食自然发热特性的影响。机械通风的效果与地槽形式密切相关,应当成为地槽设计形式的重要考虑因素。因此设计了一种环形回流通风地槽形式,对实际粮温特征具有良好的适应性,提供更加合理的压力分布和风量分布,有效降低了通风阻力、消除了通风死角并提高了通风效率。采用了计算机仿真模拟、模型试验测量和实仓试验三结合的方法。

The pattern of aeration duct plays an important role in the efficiency and uniformity of mechanical aeration utilization for grain storage. In theory, the dead - zones found in the practical operations of mechanical aeration result from the design concept of uniform air supply along the ducts. The temperature pattern of grain storage is greatly influenced by thermal characteristics of buildings and natural heating of stored grains. From the viewpoint of fluid mechanics, the pattem of duct design determines the effect of aeration, and the thermal environment as an initial condition should be considered in the facility design. A loop- shaped duct has been developed in this work. The methodology of computer simulation integrated with model test and storehouse practice was used. It is demonstrated that the developed loop duct has good adaptability to the actual temperature patterns, provides more reasonable pressure/flow distribution, reduces drag, eliminates the dead-zone and enhances aeration efficiency.