矩形肋槽烘缸的导热模型

A Heat Conduction Model of a Rectangular Ribbed Dryer

关键词:  肋槽烘缸  导热模型  传热特性

Key Words:ribbed dryer  heat conduction model  heat transfer characteristics

摘要:对矩形肋槽烘缸壁壳内的传热作了分析,考虑肋壁各处传热系数的不同,采用有限差分法建立了导热模型,通过对不同工况的计算,对肋槽尺寸对烘缸传热特性的影响进行了探讨。结果表明,增大肋宽有利于提高传热速率；在肋壁表面上的传热系数较低时,增大肋高可以提高传热速率；传热系数较高时,增大肋高,有可能使肋壁表面上的对流热阻的减小慢于导热热阻的增大,反而降低传热速率；肋效率和外壁面的温度均匀性也呈现出类似的表现。

Abstract:The heat transfer process of a rectangular ribbed dryer was investigated. Considering the different heat transfer coefficients on surfaces of the rib wall and bottom duct, a heat conduction model was presented based on definite difference method. With calculation results about a series of working conditions, the effect of geometry scale of the rib on the dryer heat transfer characteristics was analyzed. It was shown that a wider rib might increase the heat transfer rate of the dryer. Increment of rib height might result in a higher heat transfer rate of the dryer at smaller heat transfer coefficient on the rib surfaces, but a lower heat transfer rate of the dryer at higher heat transfer coefficient on the rib surfaces, it probably due to the decrease of convention heat resistance slower than the increase of heat conduction resistance on the rib surface. The rib efficiency and temperature uniformity of the outer surface of the dryer also had the similar characteristics.