Experimental and Simulative Evaluation of Temperature Increase During Fast Filling of CGH2 Tanks

To facilitate the adoption of hydrogen-based applications in the mobility sector, a reduction of the filling time is needed. However, faster filling times of compressed gaseous hydrogen (CGH2) tanks lead to a rapid temperature increase, whereby exceeding 85°C poses a safety risk due to the possibility of material failure. To prevent this, various filling protocols were developed by the SAE (e.g., J2601–5). To optimize the filling speed, infrared communication of the tank temperature between the vehicle and filling station is proposed, with the temperature measurement most likely taking place at the on-tank valve. Our experiments and simulations with filling Type III and IV tanks in the 60–320 liter range indicate a strongly inhomogeneous temperature field. By calculating the average tank temperature based on the measured tank pressure and mass, it was observed that the temperature sensor at the on-tank valve greatly underpredicts the actual tank temperature. Furthermore, the location of the hot spots within the tank depends on tank size, geometry, as well as filling parameters. Consequently, sensor placement is key for reliable measurement of the tank temperature. Similarly, the reliable temperature measurement is needed for the validation or parameter fitting of model-based approaches for predicting the tank temperature.