玉米干储一体仓气流场仿真分析与优化

为提高玉米干储一体仓中气流场均匀性,采用计算流体力学和正交试验相结合的方法对玉米干储一体仓内部气流场分布进行数值仿真和参数优化。通过单因素试验,研究水平进风管位置、竖向通风笼直径、单位通风量3个因素对玉米干储一体仓通风均匀性的影响规律,并通过系列数值仿真及正交试验对干储一体仓通风结构及参数进行优化设计。结果表明：干储一体仓内气流的平均速度,受不同水平进风管位置的影响不明显,随着竖向通风笼直径的增加呈逐渐降低趋势,而随着单位通风量的增加持续增长。速度不均匀系数随水平进风管位置从上到下变动、竖向通风笼直径增加和单位通风量增加分别呈现先减小后增大、先急剧后缓慢降低和整体增加的趋势。其中,竖向通风笼直径对干储一体仓内部流场均匀性的影响最为显著,其次是水平进风管位置和单位通风量。优化后的干储一体仓通风结构及参数的组合为水平进风管位置-0.34m、竖向通风笼直径400mm、单位通风量20m3/(h·t),此方案下干储一体仓内部流场速度不均匀系数综合加权评分值与初始方案相比提高了77.4%,表明了优化方案的可行性。

Simulation Analysis and Optimization of Airflow Field in Integrated Silo for Corn Drying and Storage

In order to improve the uniformity of airflow field in integrated silo for corn drying and storage, the computational fluid dynamics and orthogonal test method was used in numerical simulation and parameter optimization of airflow field distribution in integrated silo for corn drying and storage. By single factor experiment design, the influence of three factors, including the position of horizontal air inlet pipe, the diameter of vertical ventilation cage, and the unit ventilation volume on the ventilation uniformity of the integrated silo for corn drying and storage was studied. And through a series of numerical simulations and orthogonal experiments, the ventilation structure and parameters of the integrated silo for corn drying and storage were optimized and designed. Based on the analysis and comparison of the data and velocity cloud images obtained from the single factor experiment, it was found that the average velocity of air flow in the integrated silo for corn drying and storage was not obviously affected by the position of air inlet pipe at different levels, which was decreased gradually with the increase of diameter of ventilation cage and increased with the increase of unit ventilation volume. And the velocity non-uniformity coefficient was decreased first and then increased with the position of air inlet pipe from top to bottom, and first sharply and then slowly decreased with the increase of ventilation cage diameter, however, the overall trend of it was increased with the increase of unit ventilation volume. According to the results of single factor experiment, it was preliminarily determined that the position range of air inlet pipe was -0.34~0.34mm,the diameter range of ventilation cage was 200~400mm, and the range of unit ventilation volume was 20~40m3/(h·t). Then the orthogonal experiment of L9 (34) was designed and carried out to analyze and optimize the parameters affecting the flow field uniformity of integrated silo for corn drying and storage. Based on the comparison of the comprehensive weighted score of airflow velocity non uniformity coefficient and velocity cloud image as well as the range analysis under different combinations of the orthogonal experiment, it was concluded that the diameter of ventilation cage was the most significant influence factor on the airflow field uniformity of integrated silo for corn drying and storage, followed by the position of horizontal air inlet pipe and the unit ventilation volume. The optimized ventilation structure and parameters of the integrated silo for corn drying and storage were as follows: the position of horizontal air inlet pipe was -0.34m, the diameter of vertical ventilation cage was 400mm, and the unit ventilation volume was 20m3/(h·t). Under this scheme, the comprehensive weighted score of velocity non-uniformity coefficient of the integrated silo for corn drying and storage was 77.4% higher than that of the initial plan, indicating the feasibility and practical application value of the optimized scheme. The research results can provide theoretical guidance and technical support for the ventilation structure and parameter optimization design of the integrated silo for corn drying and storage.