Research On Technological Parameters Of High Pressure System In Hydrogen Refueling Station

Due to the pressing problem of energy sources crisis and environment pollution, it has become an urgent need to exploit new clean and efficient power. Hydrogen has long been considered as an important secondary energy source of the 21st century by the merits of its high combustion efficiency, clean products and the capacity to be regenerated. Along with the booming development and industrialization of hydrogen fuel cell and electric automobile, the development of hydrogen refueling station has been paid more and more attention all over the world.Nowadays, the construction of hydrogen refueling station is still at its pilot period yet. This thesis, sponsored by 863 Hi-Tech Research and Development Program of China on the topic of Technique and Equipment of High-pressure Hydrogen Storage (NO. 2006AA05Z143), takes deep insight into a set of technologic parameters of high-pressure system in hydrogen refueling station, and makes specific efforts from the perspectives as followed:(1) Flow and velocity of hydrogen. Based on the Real State Equation of Hydrogen and basic theories of gas kinetics, a calculation method of flow and velocity of hydrogen has been proposed, which provided a technical support for evaluating the fast filling capacity of hydrogen refueling stations. According to the analysis of hydrogen velocity characteristic of hydrogen refueling station, the author found out the restrictions on hydrogen flow velocity of present standard are too rigid, and thereby suggested to appropriately broadened that restrictions in engineering design.(2) Filling rate. The author has built a theoretical model regarding temperature increase during the process of fast filling the on-board hydrogen storage vessel, and used data from foreign experiments to modify that model to make it more applicable. As a result, it has been approved that the maximum permissible filling rate is influenced by filling pressure of on-board vessel, gross volume, initial pressure, source pressure of hydrogen refueling station, and ambient temperature etc.(3) Utilization ratio of hydrogen. The author has also brought forward amethod to calculate the hydrogen utilization ratio of hydrogen refueling station both in single-step and multi-step refueling. It can be found that the multi-step refueling is obviously better than the single-step refueling in terms of hydrogen utilization ratio, therefore the former is suggested to be used in hydrogen refueling stations. Moreover, hydrogen utilization ratio is also influenced by the capacity ratio of different vessel groups, and the optimal vessel capacity ratio between the latter group and the former group in hydrogen refueling stations is about 1:2.