Study On Effective Thermal Conductivity Of Two-Phase Granular Porous Materials

Industry more than 50% of the products and intermediate products are granular, but solid–gas of two-phase granular porous materials as the main among them. There were few research reports concerning the analysis and verification of various prediction models based on experimental data for solid-gas two-phase materials. From the theoretical analysis and experimental study to research on effective thermal conductivity of two-phase granular which on the basis of domestic and foreign thermal conductivity of porous materials research, It mainly includes the following elements:1,The use of density method to measure porosity of typical two-phase granular porous materials, and determine the gas phase, solid-phase pure thermal conductivity;2,Introduction effective thermal conductivity of testing methods of porous materials, and theory of hot wire and cut-out hot wire, the cut-out hot wire method was used to measure effective thermal conductivity of quartz sand, silicon carbide, sand and coal dust in this paper. The results indicated that: the effective thermal conductivity decreases as the material porosity within porosity in the test;3,Analysis and calculate uncertainty for the experimental equipment. The results showed that: the maximum uncertainty of±0.0070W/(m·K), the minimum of±0.0030W/(m·K), it has a high measuring accuracy;4,Introduction seven mathematical models which regularly predicted effective thermal conductivity of granular porous materials are summed up in this paper, and test results were compared with prediction model values. The results indicated that, Kunii and Smith model is the best fit with the experimental test results and the error is smallest;5,Using least square method to curve fitting with data which were the measured effective thermal conductivity of materials, a new prediction model with considering the impact of porosity is established by amending Kunii and Smith mode with test data in this paper;6,The accuracy of correction model is verified by comparing with the measured effective thermal conductivity given by foreign.