花椒烘干房温度场模拟及优化研究

Simulation and optimization of temperature field in pepper drying room

花椒是我国传统的调味品,其品质直接受干燥效果的影响,而干燥过程的温度场分布是主要影响因素。因此,在理论分析和实际工程调研的基础上,确定了适用于花椒烘干房温度场研究的物理模型、边界条件及烘干各阶段的送风参数,应用Fluent软件分别模拟了未优化方案(风口浮射出流)和优化方案(顶板加辐射)下房内温度场的分布情况,并对模拟结果进行了对比分析,结果表明:(1)未优化时,风流进入空间后,卷吸的冷空气量逐渐增多,射流温度发生变化,风口附近产生冷热不均现象。(2)优化后总体温度分布更加均匀,最高温度区域大多向风口两侧发展。气流扩大产生的卷吸作用更加强烈,使得温度分布均向风口侧发展的趋势更加明显。(3)优化后主流温度基本保持在初始温度附近变化,而后主流温度缓慢上升,当X=2.5m附近处时,各阶段主流温度上升的走势停滞,气流分层现象较明显。(4)优化后主流从热风出口几何中心的左右两侧逐渐向中心位置出现明显偏移,最大的偏移距离达0.8m。

Chinese prickly ash is a traditional condiment in China, and its quality is directly affected by the drying effect. Temperature field is the main influencing factor. On the basis of theoretical analysis and practical engineering investigation, the physical model, boundary conditions and air supply parameters suitable for the study of temperature field in Pepper drying room are determined. Fluent software was used to simulate the distribution of temperature field in the room under the non-optimized scheme (tuyere buoyant efflux) and the optimized scheme (roof plus radiation), and the simulation results were compared and analyzed. The results show that:(1) When the air flow enters the space, the amount of cold air entrained increases gradually, the jet temperature changes, and the uneven cold and heat phenomena occur near the tuyere.(2) After optimization, the overall temperature distribution is more uniform, and the maximum temperature area mostly develops to both sides of the tuyere. The entrainment effect caused by the enlargement of airflow is more intense, which makes the temperature distribution develop towards the tuyere side more obvious.(3) After optimization, the mainstream temperature basically keeps changing near the initial temperature, and then the mainstream temperature slowly rises. When X=2.5 m is near, the trend of the mainstream temperature rises stagnates, and the stratification phenomenon of airflow is obvious.(4) After optimization, the displacement of the mainstream from the left and right sides of the geometric center of the hot air outlet to the center gradually becomes obvious, and the maximum displacement distance reaches 0.8 m.