基于分布参数模型的多通道烘缸传热模拟

Prediction of the heat transfer performance of multi-channel cylinder dryer based on a distributed parameter model

建立了多通道烘缸通道内蒸汽冷凝换热的分布参数模型,分析了不同结构参数对多通道烘缸传热和流动特性的影响。通过对某一纸机的性能进行模拟分析,考察了通道数量及高宽比等参数对蒸汽冷凝换热和流动特性的影响。结果表明:在1个给定的高宽比下,通道数量有一最优值,在该通道数量下,蒸汽恰好完全冷凝成水,且通道中释放的热量与纸张蒸发所需的热量一致;同时,高宽比太小会导致通道设计的精确性增大,而高宽比太大则会使得沿程阻力增加,因此,选择高宽比在1/3~1/6较为合理,所建模型可作为多通道烘缸通道设计的理论依据。

A distributed parameter model is developed for steam condensing in the multi-channel cylinder dryer.The heat transfer performance and flow characteristic under various structural parameters are analyzed.The model is applied to predicting the performance of one paper machine,and the influences of the number of channels and aspect ratio on the heat transfer performance and flow characteristic are studied.The results show that the number of channels has an optimal value under a given aspect ratio,with the optimal channel number,the steam is completely condensed and the steam heat is fully released.Meanwhile,it is reasonable for chosen the aspect ratio between 1/3-1/6,small aspect ratio may increase the accuracy of design and large one can increase the frictional resistance.The results show that the present model can be used to analyze and design the multi-channel cylinder dryer.