Comparative study on thermal and mechanical performances of liquid lead thermocline heat storage tank with different solid filling material layouts

The main novelty of this paper is the influence evaluation of different layouts of three solid filling materials (SFMs) on the operation and mechanical performances of liquid lead thermocline sensible energy storage (TSES) tank, which are alumina ceramic, high-temperature concrete and copper foam. By using simulation method, charging, discharging and mechanical performances of the TSES tank using six different layout cases are analyzed and compared. The results show that when copper foam is arranged as the first SFM layer, discharging performance of the TSES tank can be improved. When the upper, middle and lower SFM layers are copper foam, alumina ceramic and high-temperature concrete, the TSES tank has the best discharging performance, with the highest effective discharging quantity (1.224 × 10 10 J), average discharging power (6.73 × 10 5 W) and discharging efficiency (98.1 %). When alumina ceramic, high-temperature concrete and copper foam are arranged as the upper, middle and lower SFM layers, the steel wall of the TSES tank has the lowest peak maximum mechanical stress (92.9 MPa), showing the best mechanical performance. This paper will provide certain reference for optimizing both the thermal and mechanical performances of TSES tanks.