Study On Flow Characteristics Of High Pressure And Low Temperature Hydrogen

In the contemporary society,the demand for energy consumption is great and the pursuit of environmental protection is being pursued,while the traditional non-renewable energy sources such as petroleum,natural gas and other fossil fuels are depleted day by day,so the search for a clean,controllable and safe new energy has become a growing demand.Hydrogen energy has become one of the main concerns in the new energy industry because of its high energy density,clean and environmental protection,especially in the field of transportation.Hydrogen fuel cell vehicles have also emerged as the times require.With the development of the hydrogen fuel cell automobile industry,higher requirements are put forward for the construction of hydrogen energy infrastructure,the matching of parameters and the control strategy of hydrogen charging rate in the hydrogenation process of hydrogenation station.Based on the 70 MPa liquid hydrogen storage and hydrogenation project built by Beijing institute of Aerospace Test Technology,this paper redevelops the fitting state equation of real gas suitable for describing hydrogen flow in hydrogenation station by means of user-defined gas model UDRGM,aiming at the real gas effect in the process of medium-high pressure and low-temperature hydrogen flow in hydrogenation station,and establishes the CFD calculation of high-pressure and low-temperature hydrogen gas.The real gas model,which can be directly invoked,is compared with the existing real gas model based on semi-empirical equation(R-K equation,MBWR equation).Finally,it is determined that the real gas model described by fitting equation can be used as the basis of CFD calculation to improve the simulation accuracy and reduce the amount of calculation.The throttle expansion process of hydrogen flow through the pressure relief valve in hydrogenation plant is simulated and analyzed.The influencing factors of Joule-Thomson effect and the temperature-pressure change rule before and after the pressure relief valve are obtained within the range of commonly used process parameters in hydrogenation station.The simulation conclusion that 12-37℃ is produced after the pressure relief valve in hydrogenation station is put forward to throttle the hydrogenation machine.The parameter setting of the process provides a certain basis.The high pressure hydrogen cylinder charging and discharging system with orifice plate group as throttling element was used to carry out 90 MPa pressure level cylinder charging and discharging experiments.The accuracy of the calculation model of hydrogen throttling expansion process was verified by comparing the simulation results with the experimental data.According to the latest hydrogenation standard SAE-J2601-201612 R,the system-level simulation software AMESim is used to simulate the hydrogenation module in the hydrogenation station in detail.The control strategy of the temperature rise of the hydrogen storage cylinder and the filling rate of hydrogen gas is put forward.Considering the throttling effect in the hydrogenation system,the basis of the temperature of the gas source is given.A hydrogenation mode with variable average pressure change rate is proposed,which can shorten the hydrogenation time and save the cooling capacity for the gas source temperature pre-cooling device,and optimize the parameter matching settings of the hydrogenation station system.