Theoretical investigation on inverse identification of spectral properties of paraffin phase change materials based on multi-thickness model

摘要

Paraffin as an organic phase change material with high latent heat and stable physical and chemical properties, is widely used as building filling materials to absorb and store solar energy. And the spectral properties of paraffin is crucial to study the phase change characteristics of paraffin materials in absorbing solar energy. Therefore, this work studies theoretically the inverse identification of spectral properties of paraffin phase change materials. A multi-thickness model is developed to determine the optical constants (spectral refractive index and absorption index) of paraffin materials in solid and liquid state based on transmittance data. This model overcomes ill-posed and multiple solution of inverse problems. An improved quantum particle swarm optimization algorithm is adopted to determine spectral refractive index and absorption index of paraffin materials with high accuracy. A serious of numerical experiments are implement to study retrieval problems thoroughly and results show that the inverse strategy we develop is a promising technique to obtain spectral properties of paraffin materials.