Study on performance enhancement and heat transfer regulation simulation of phosphogypsum-based phase change cementitious material

Abstract

Phosphogypsum-based building materials hold great promise as a key method for managing solid waste. However, their limited thermal storage capacity restricts their widespread application in engineering. In this study, microcapsule phase change materials (MPCMs) were introduced to enhance heat storage capacity, while anhydrous calcium sulfate acicular crystals (ACSW) and quicklime were added to compensate for the composite's strength deficiencies. A performance-enhanced phosphogypsum-based phase-change cementitious material (PPCCM) was prepared, and its temperature controlling and energy-saving benefits were investigated through numerical simulations. Results indicate that the optimum strengthening effect occurs when the ACSW content is 3.5% and the quicklime content is 6%. Simulation results validate that PPCCM offers excellent thermal regulation and energy-saving benefits. Taking summer operating conditions as an example, the daily temperature variation on the inner surface of the two PPCCMs with different phase-change temperatures can be reduced to 1.74°C and 0.40°C, respectively, achieving energy savings rates of 6.93% and 6.69%. When extended to cover a wide range of seasonal conditions, the temperature control of the PPCCM exhibits strong seasonal sensitivity, while its energy-saving benefits show weaker sensitivity. This study proposes a new method for enhancing the performance of PPCCM and reveals the temperature regulation and energy-saving characteristics of this material when used as interior wall plaster. It provides new insights and practical examples to promote the application of phosphogypsum-based building materials.