Thermocline energy storage systems can be adapted to store energy in a tank where the hot fluid is pumped in during a charging cycle and cold fluid during a discharging cycle, substituting the need for two storage tanks. Here, a numerical investigation of a hot air flow transferring thermal energy to a solid porous bed is performed to evaluate the influence of the thermal conductivity and capacity ratios on the efficiency of a charging cycle of a thermocline storage tank. The numerical model considers the mixed convection turbulent flow (k- ε model) through clear and porous media using the Local Thermal Non-Equilibrium approach to provide solutions for the solid and fluid phases separately. Macroscopic equations are obtained by the method of volume averaging and numerically processed by finite volume method. The system was modelled as a vented axisymmetric cavity, partially filled with a porous medium, with hot fluid inflow from the top and outflow at the bottom. The investigation included changing Reynolds number (Re_t from 8.3x10³ to 5x10⁴), thermal conductivity ratios ($k_s/k_f$ from 3.5 to 1062) and thermal capacity ratio (${\rho }_s{c}_{\mathit{ps}}/{\rho }_f{c}_{\mathit{pf}}$ from 1483 to 7415). It was found that lower $k_s/k_f$ ratios decrease the heat loss throughout the charging cycle which allow for higher temperatures in the later stages of the cycle and thus improve charging efficiency. However, this effect decreases in importance as the system undergoes higher Re_t number flows. On the other hand, increasing the ${\rho }_s{c}_{\mathit{ps}}/{\rho }_f{c}_{\mathit{pf}}$ ratio affects the entire cycle, increasing the temperature difference between phases, lowering the velocity in which the solid raises its temperature but storing heat more efficiently. Finally, a design consideration is highlighted as the importance of the $k_s/k_f$ ratio on the thermal efficiency is predominant at lower Re_t flows, whereas as Re_t increases, ${\rho }_s{c}_{\mathit{ps}}/{\rho }_f{c}_{\mathit{pf}}$ becomes the dominant parameter providing efficiency gains.

温跃层能量存储系统可适合于在储罐中存储能量，在储罐中，在充电周期中泵入热流体，而在排放周期中泵入冷流体，从而代替了两个储罐。在此，对将热能传递到固体多孔床的热气流进行了数值研究，以评估热导率和容量比对温跃层储罐的充电循环效率的影响。数值模型使用局部热非平衡方法考虑通过透明和多孔介质的混合对流湍流（k-ε模型），以分别提供固相和液相的解决方案。通过体积平均法得到宏观方程，并通过有限体积法对其进行数值处理。该系统被建模为一个通风的轴对称腔，部分填充有多孔介质，热流体从顶部流入，在底部流出。调查包括更改雷诺数（重新_吨从8.3×10 ³至5×10 ⁴），热导率比（${ķ}_s/{ķ}_F$ 从3.5到1062）和热容比（${\rho }_s{C}_{\mathit{ps}}/{\rho }_F{C}_{\mathit{pf}}$从1483到7415）。发现较低${ķ}_s/{ķ}_F$这些比率降低了整个充电循环中的热损失，这允许在循环的后期阶段中具有更高的温度，从而提高了充电效率。然而，这种效果在作为系统经受更高的重要性降低再_吨数流动。另一方面，增加${\rho }_s{C}_{\mathit{ps}}/{\rho }_F{C}_{\mathit{pf}}$比率会影响整个循环，增加相之间的温度差，降低固体升温的速度，但会更有效地存储热量。最后，强调设计的重点是${ķ}_s/{ķ}_F$上的热效率比在较低的主要重新_吨流动，而作为再_吨增加，${\rho }_s{C}_{\mathit{ps}}/{\rho }_F{C}_{\mathit{pf}}$ 成为提高效率的主要参数。