Simulation and optimization research of double energy storage floor based on heat transfer characteristic of phase change materials

According to statistics, the construction industry accounts for more than 40% of the global energy consumption, and the form of building energy conservation is urgent and has great potential. The application of phase change energy storage technology in radiant floor is considered as an effective way to realize building energy efficiency. In this paper, a novel model of double-layer phase-change radiant floor for energy storage was established considering the phase change characteristics of PCM in the process of energy storage and release. Based on the model, the effect of PCM material phase transition temperature zone and its width on the heat transfer performance of floor was simulated and analyzed. Then, the influence mechanism of physical parameters such as tube pitch, tube diameter and tube position on energy storage and discharge process was further studied. Considering the natural convection in the PCM phase transformation process, aiming at the shortest energy storage time, the longitudinal position of the pipeline was optimized by dichotomy method. Compared with the initial setting model, the energy storage time in winter and summer could be shortened by 5 h and 2.5 h respectively, thus further reducing the heating heat consumption of the building. •Based on the characteristics of PCM, a new model of two-layer phase change energy storage floor was established.•Considering the effect of natural convection, the reasonable position of capillary was determined by dichotomy method.•Compared with the conventional physical model, the optimized model has obvious energy-saving effect.