# Analysis of Hydrogen Filling of 175 Liter Tank for Large-Sized Hydrogen Vehicle
###### Abstract  
Due to the low density of hydrogen gas under ambient temperature and atmospheric pressure conditions, the high-pressure gaseous hydrogen storage method is widely employed. With high-pressure characteristics of hydrogen storage, rigorous safety precautions are required, such as filling of compressed gas in a hydrogen tank to achieve reliable operational solutions. Especially for the large-sized tanks (above 150 L), safety operation of hydrogen storage should be considered. In the present study, the compressed hydrogen gas behavior in a large hydrogen tank of 175 L is investigated for its filling. To validate the numerical approach used in this study, numerical models for the adaptation of the gas and turbulence models are examined. Numerical parametric studies on hydrogen filling for the large hydrogen tank of 175 L are conducted to estimate the hydrogen gas behavior in the hydrogen tank under various conditions of state of charge of pressure and ambient temperature. From the parametric studies, the relationship between the initial SOC pressure condition and the maximum temperature rise of hydrogen gas was shown. That is, the maximum temperature rise increases as the ambient temperature decreases, and the rise increases as the SOC decreases. s 2022 20220220220220220220220220220220220220220222022022202220222022220  
researchers have conducted studies on the prediction of the compressed hydrogen gas (CGH\({}_{2}\)) behavior for its filling and fueling in a hydrogen tank for hydrogen vehicles. With these trends, Chung et al. [8] conducted a feasibility study applying the boiling model to analyze the multiphase-thermal flow in the pipe considering the phase change. Johnson et al. [9] developed thermal models for the filling of high-pressure hydrogen tanks with experimental validation using two models. They conducted numerical studies using the validated numerical model. Zhao et al. [10] investigated a CFD model, including modified standard k-epsilon turbulence and real gas model to predict the fast filling process of a type III (with metal liner) hydrogen vehicle cylinder with 74 L. Thermodynamic responses of fast filling under different pressure-rise patterns and filling times have been analyzed. From the above study, it is worth considering what happens to the tank in the case of fast filling in terms of heat and fluid flow. Suryan et al. [11] conducted a numerical simulation of the filling process of hydrogen tanks considering real gas effects. The effect of changes in ambient temperature and initial and inlet gas temperatures is studied. However, a large-capacity hydrogen tank is required for long-distance transportation, such as that involving trains and ships. Additionally, the increasing demand for long-distance transportation and hydrogen vehicles using CGH\({}_{2}\) has been increased considering the system operations and controls. Therefore, research on large-capacity hydrogen storage tanks is required, especially for its charging phenomenon considering hydrogen gas temperature and pressure variations. Jun Liu et al. [12] examined the fast filling (3, 5 min) and 10 min holding process of 150 L on-bus type III and type IV gaseous hydrogen storage cylinder using a two-dimensional (2D) axisymmetric model. T. Bourgeois et al. [13,14] studied hydrogen vehicle refueling requirements for the temperature limits to the tank, specification of the average delivery temperature. They developed new models of various types for predicting both the gas and material temperatures inside a vessel during filling and defueling. Li et al. [15] studied the effect of hydrogen temperature rise in 120 L type IV hydrogen cylinder to predict the influence on temperature with different ratios of length to diameter, different inlet diameters of cylinders, and different types of mass flow rate. Numerical studies should be based on the validated gas and turbulence model.