A Comparative Study On Lumped Parameter Models For Hydrogen Refueling Simulation

With the development of the global automotive industry,energy shortage and environmental pollution have become two major problems for the sustainable development of the automotive industry.Hydrogen energy has some advantages such as environmentally friendly and high energy density,it is an idea alternative energy for fossil fuels.The fuel cell vehicle uses hydrogen to supply energy,and the hydrogen storage is realized by the on-board compressed hydrogen storage tank.Due to the thermal effect of the refueling process,the hydrogen temperature and pressure in the compressed hydrogen storage tank rise rapidly in a short time.In order to ensure the safety and efficiency of hydrogen refueling process of fuel cell vehicles,it is important to establish an effective model to predict the parameters such as hydrogen temperature and pressure during the refueling process.In order to solving above problem,the theoretical model of hydrogen refueling is used in this paper.Firstly,the energy conservation equation for single-zone(gas zone)model and the dual-zone(gas zone,wall zone)model under fixed charge/discharge temperature,variable charge/discharge temperature,dormancy process and analytical solution of hydrogen temperature of MC(composite mass and heat capacity)method are derived.Secondly,the above energy conservation equation is transformed into a differential equation about hydrogen temperature and tank wall temperature.The differential equation is solved by analytical method and numerical method.By comparing the solutions,the effectivenss of solutions is verified and the chargedischarge cycles of Type III 25 L and Type IV 99 L compressed hydrogen tank are simulated by using single-zone model.Then,the dual-zone model is used to simulate the hydrogen refueling process of MC default refueling,the simulated data and experimental data are compared to verify the effectiveness of the dual-zone model under real fueling conditions.Finally,the refueling process of Type III 25 L and Type IV 174 L compressed hydrogen storage tanks under different fueling parameters(ambient temperature,hydrogen mass inflow rate,initial pressure)are simulated by using dual-zone model,the relationship between the parameters and final hydrogen temperature can be obtained by parameter fitting method.The results show that the temperature calculation of the single-zone model and the dual-zone model can be transformed into differential equations.The analytical and numerical methods can solve the hydrogen temperature during the charge-discharge cycles under different charging conditions and the results are consistent.The comparison of MC method refueling experimental data and dual-zone model simulated data indicates dual-zone model is valid.The ambient temperature,the hydrogen mass inflow rate and the initial pressure have impact on the hydrogen filling process.The higher the ambient temperature,the higher the final hydrogen temperature and the slower the temperature rise.The higher the hydrogen hydrogen mass inflow rate,the higher the rate of hydrogen temperature rise during the pre-charging period.The higher initial pressure,the lower the rate of hydrogen temperature rise in the pre-charging period,the higher the rate of temperature rise in the end stage of refueling.The parametric study shows that during the refueling process,the selection of reasonable refueling parameters can control the temperature rise effectively during the and improve the safety of the hydrogen filling process.