梯牧草草捆压缩蠕变特性的影响因素分析

Effective factors on timothy hay creep properties when compressed to high density

蠕变是决定纤维状生物质压缩的一个重要特性,不同的蠕变特性影响压缩过程的能耗.为分析出最佳原料匹配参数,达到降低压缩能耗的目的,采用Burger模型,分析了在不同含水率和切段处理条件下梯牧草的压缩蠕变特性.非线性回归分析显示,Burger模型适用于梯牧草草捆的压缩蠕变过程;试验结果表明含水率对蠕变特性产生较大影响,切段在一定程度上影响蠕变;通过统计学中的主成分分析,将影响蠕变特性的因子分为弹性因子和粘性因子,这两个因子包含了蠕变特性中86.45%的信息;较高含水率条件下不论是否切段,梯牧草的弹性和粘性均较弱.由此得出,在较高含水率条件下时,梯牧草压缩所需能耗应较低.

Creep property has significant effect on fibrous biomass compress processing.Different creep properties influence the energy consumption during compacting.In order to investigate the proper parameters for compression process,four elements Burger′s model was introduced and the creep properties of timothy hay bales were analyzed under different moisture contents and lengths.The results show that this model fits the data well and those two conditions influence the creep properties especially the moisture content.It was found that two factors had significant effects on the creep： elastic factor and viscous factor.These two factors contained around 86.45% of creep information.Timothy hay bales show lower values of elasticity and viscosity under high moisture content than those under low moisture content.Meanwhile,the length of timothy grass has no effects on these values when the grass has high moisture content.Therefore,it is concluded that it will consume less energy when timothy hay is compressed to hay bale under high moisture content than those under other conditions.