Investigations on temperature variation within a type III cylinder during the hydrogen gas cycling test

In order to evaluate the expected on-road performance of the compressed hydrogen gas (CHG) cylinder, the cycling test with hydrogen gas has been considered as an effective method. During the gas cycling test, the gas temperature in the cylinder changed in a wide range, which was restricted in relevant standards such as GTR-HFCV, ISO/DIS 15869. Therefore, it is necessary to investigate the temperature change in the cylinder during the cycling test. In this paper, gas discharging experiment was conducted and a model was presented for simulating and describing the thermal behavior during the cycling test. The effects of ambient temperature, refueling gas temperature, starting mode, refueling time and discharging flow rate on the temperature variation were analyzed and discussed in detail to catch the key influencing factors of the temperature variation. Finally, we find the temperature will be stable after several cycles and the refueling gas temperature has a significant effect on the stable temperature. This study is useful for understanding the gas thermal behavior during the gas cycling test and can be used to determine the optimal experimental conditions.