A Fractal Model for VOCs Diffusive Transport in Dry Porous Building Materials

摘要：

In order to study the effect of microscopic structure characteristics on the VOCs diffusive transport in building materials, a fractal model is developed and analyzed to investigate the mass transfer characteristics of VOCs diffusive transport in dry porous building materials. The classical Ficks diffusion law is extended to a fractal diffusion model in this work. Using the method of separation variables, the theoretical solution of VOCs fractal diffusion model in a porous structure is obtained. Combined with the microscopic structure characteristics, the VOCs diffusion process in dry porous building materials is simulated by using different surface fractal dimensions and fracton spectral dimensions. The simulated results show that the surface fractal dimensions and fracton spectral dimensions exhibit different effects on the VOCs migration process in dry porous building materials. The increase of the surface fractal dimension demonstrates the increase of specific surface area. The fracton spectral dimension affects the VOCs diffusive transport remarkably in the early stage, but the distinction between different hysteresis effects caused by different fracton spectral dimensions is becoming increasingly small with respect to the diffusion time. Both the surface fractal dimensions and fracton spectral dimensions reflect the influence of fractal structures on VOCs diffusive transport. Combining the surface fractal dimensions with fracton spectral dimensions provides a farther interpretation for the VOCs diffusion process in dry porous building materials.

关键词： Porous building materials Mass transfer Fractal model

作者: Xiaozhong Shen Zhenqian Chen Changhai Peng Min Li

作者单位: School of Energy and Environment,Southeast University,Nanjing,China Department of Electric Engineeri School of Energy and Environment,Southeast University,Nanjing,China ISSUE,Southeast University,Nanji ISSUE,Southeast University,Nanjing,China School of Architecture,Southeast University,Nanjing,China ISSUE,Southeast University,Nanjing,China School of Material Science and Engineering,Southeast Univer

会议类型: 国际会议

会议名称: The 6th International Symposium on Heating,Ventilating and Air Conditioning(第六届国际暖通空调学术会议)

会议地点: 南京

会议语种:英文

页码: 1192-1198

在线出版日期: 2009-11-06（万方平台首次上网日期，不代表论文的发表时间）