Calculation of transient phase change heat transfer through building envelopes: An improved enthalpy model and error analysis

Abstract

It is important to accurately predict the transient heat transfer process through building envelopes that have been enhanced with phase change materials (PCMs). An improved two-dimensional (2D) model, based on the enthalpy method, is presented in this paper. The proposed model handles, among other features, PCM’s thermo-physical parameters, various melting and solidification temperature ranges, and multiple temperature turning points during phase change, more precisely than existing models (Zhang et al., 2011; Sharma et al., 2006; Sadasivam et al. 2011) [1–3]. The model was verified against experimental data from measurements in a concrete masonry units (CMUs) wall outfitted with PCMs. The results from the model verification indicated that the deviations of the proposed model were less than 0.40 °C for standard deviation and 0.80 °C for maximum deviation under the studied conditions. The corresponding relative errors were less than 2.9% for standard deviation and 5.7% for maximum deviation. The proposed model is necessary for the accurate calculation of and prediction of transient heat transfer through wall in the presence of PCMs.