Abstract: Solid matrix structure, which has significant effect on its transfer properties, has not been systematically studied.In this paper, steam-exploded rice straw（SERS)and inoculum were used as the solid phase and liquid phase of substrates, the change of water retention, permeability and thermal conductivity of substrate with the variation of its three-phase structure was investigated within the particle size range（6.5—0.4 cm)and moisture content range（60%—85%)which was employed in industry.The results showed that liquid phase dominated the phase structure variation, therefore, a three-phase structural index（TPSI)was proposed based on weighted variation coefficient.Water evaporation rate of substrate showed exponential increase with the rise of TPSI, and obvious fluctuation was accompanied, indicating that there were some other factors influencing the water retention of substrate. The effect of particle size on substrates’ permeability weakened gradually with increase of water content, and its variation with TPSI accorded with Bidoseresp function（R2=0.9025).The thermal property of substrate, such as volumetric specific heat, thermal resistivity and thermal conductivity, varied with the increase of TPSI according to power exponent functions（R²=0.8991, 0.9135, 0.9053);small fluctuation indicated that the effect of water content was stronger than that of particle size.Statistical analysis also proved that the TPSI can reflect comprehensive influence of moisture content and particle size on substrates’ transfer properties.Therefore, the TPSI can be applied to effectively characterize the effect of substrate structure on its transfer properties.

Key words: moisture content, particle size, three-phase structural index, water retention, permeability, thermal conductivity

摘要： 以汽爆稻草和培养液分别作为基质的固、液相，讨论了工业发酵颗粒尺寸（6.5～0.4 cm）和含水量（60%～85%）范围内，基质的保水性、透气性及热导性随三相结构变化的规律。液相在三相结构变化中起主导作用，进而提出基于变异系数权重法的三相结构指数；基质水分蒸发速率随三相结构指数呈指数增加趋势，并伴有明显波动，表明基质保水性受三相组成外其他因素的影响；基质透气性与三相结构指数的关系符合Bidoseresp函数；基质的热性质（比热容、热阻、热导率）随三相结构指数的增加呈幂指函数变化趋势。统计分析同时佐证了三相结构指数能够反映基质含水量和颗粒度两因素对传递性质的综合影响。所建立的三相结构指数能够用于明确表征基质结构对其传递性质的影响，具有宏观指导意义。

关键词: 含水量, 颗粒尺寸, 广义三相结构指数, 保水性, 透气性, 热导性