## 4 Results
### Comparison: Reference vs. Alternative Concept  
The exemplarily shown simulation results serves as basis for calculating the systemic storage densities, heat losses and thermal cooling powers as well as for evaluation of the alternative concept in comparison to the reference. For this purpose, Figure 8 illustrates the systemic storage densities resulting from the wide simulation studies as a function of the thermal cooling power. The reference concept without active cooling (\(\dot{Q}_{F,c}=0\)) reaches a volumetric and gravimetric systemic storage density of 169.2 Wh/kg and 56.3 kWh/m\({}^{3}\) at the maximum permitted surface temperature of 60 \({}^{\circ}\)C, whereas the alternative concept achieves storage densities of up to 284.9 Wh/kg and 311.3 kWh/m\({}^{3}\). These improvements are based on the integrated bypass and the associated active thermal cooling powers (\(\dot{Q}_{F,c}\)). At the limit case--minimal active cooling powers depending on the gravimetric systemic storage densities (black curve)--thermal cooling powers from 123.4 W to 600 W are needed within the scope of the investigated gap and thermal insulation thicknesses. Due to additional considered storage medium dimensions within the systemic storage densities, the minima in the thermal insulation masses as shown in Figure 7 are only weakly visible here. In addition to the systemic storage densities and thermal cooling powers, the resulting heat losses serve as a further value for comparison and evaluation of the alternative concept (Figure 9). Figure 8: Systemic storage densities of the reference and the alternative concept as a function of the resulting thermal cooling powers (\(\dot{Q}_{F,c}\)). As already described in Section 4.2.2, the results show that increased cooling powers (\(\dot{Q}_{F,c}\)) are associated with reductions in storage dimensions and thus in heat losses (\(\dot{Q}_{loss}\)). In relation to the limit case--minimal active cooling powers depending on the gravimetric systemic storage densities (black curve). This results in a decrease in heat loss from 155.3 W for the reference concept to up to 38 W for the alternative concept. The presented results point to significant improvements in systemic storage densities with minor thermal cooling powers through the integration of the bypass path inside the thermal insulation. For the limit cases--illustrated by the black curves--the associated insulation and gap thicknesses are shown in Figure 10.  
The context between decreasing gap thicknesses (\(\Delta s_{F}\)) and increasing systemic storage densities (coloured dots) due to the associated improved cooling efficiency becomes visible, as already described previously. In addition, the results show that the inner insulation (\(\Delta s_{1}\)) dominates and makes the essential contribution to total thermal insulation. This effect is caused by significantly decreasing heat transports via radiation with increasing inner insulation thickness and leads--together with the convective cooling--to small required outer thermal insulation dimensions. Even by very small fluid gaps and thus high convective cooling rates, the inner thermal insulation thickness dominates with over 90%  
Figure 10: Ratio of outer to inner thermal insulation thickness (\(\Delta s_{2}/\Delta s_{1}\)) and gravimetric systemic storage densities (\(Q/m_{tot}\)) for the limit case as a function of the cooling fluid gap (\(\Delta s_{F}\)). Figure 9: Heat losses (\(\dot{Q}_{loss}\)) and volumetric systemic storage densities of the reference and the alternative concept as a function of the resulting thermal cooling powers (\(\dot{Q}_{F,c}\))  
Based on these first results and contexts presented here, the systemic advantages of the alternative concept become obvious. Compared to the specified thermal discharge power of 5000 W, only low active cooling rates of less than 600 W are required even at design solutions with high systemic storage densities of up to 284.9 Wh/kg and 311.3 kWh/m\({}^{3}\).