Analysis of thermal storage performance in low-temperature heating floor based on phase-change paraffin wax

ZHENG Huifan; GAO Huiyao; TIAN Guoji; ZHAO Menghao; TIAN Yibo; ZHANG Xinyu; WANG Jiabin

doi:10.3969/j.issn.1671-6906.2025.04.012

Abstract：To evaluate the heat transfer characteristics of a phase-change thermal storage floor under low-temperature heating conditions,a physical model of a thermal storage floor containing phase-change paraffin wax was established in this study.Numerical simulations were conducted to analyze variations in the liquid phase rate of the phase-change layer,the temperature of the phase-change lay-er,and the surface temperature of the floor.The results show that when the heating supply tempera-ture was 32℃,the paraffin with a phase-change temperature of 23℃ completely melted at 3002?s,while the paraffin with a phase-change temperature of 28℃ reached a liquid phase rate of 0.428 by the end of the charging process.When the heating temperature was reduced to 28℃,the paraffin com-pletely melted at 9165 s.Under a heating temperature of 26℃,the liquid phase rate of the paraffin was 0.532 at the end of charging.It was determined that under low-temperature heating conditions,the optimal phase-change temperature of the paraffin is 23℃,corresponding to a minimum heating supply temperature of 28℃ for the floor.Higher heating temperatures resulted in closer melting times of the paraffin.After the paraffin was completely melted,the rate of temperature increase at the floor surface slowed down and gradually stabilized.The average surface temperature of the floor re-mained above 23 ℃,meeting the required heating temperature conditions.This study confirms the feasibility of using phase-change thermal storage floors in low-temperature heating systems and pro-vides a basis for selecting the phase-change temperature of the material.