A Cycle Analysis of Flow and Thermal Parameters in the Hydrogen Charging System at the Pressure of 50 MPa

Abstract

In the currently developed hydrogen compression cycle system, hydrogen is compressed through a compressor and stored in a tank at high pressure. In the filling process from A (tube trailer) to B (high-pressure tank), thermal stress in the B arises due to the temperature rise of hydrogen together with the internal pressure increase in the tank. In the study, in order to achieve safe filling, it is necessary to investigate the flow and thermal parameters of the system. Based on the principles of thermodynamics, a thermodynamic prediction model for the temperature change during the hydrogen cycle was established by comprehensively considering the real state of gas, convective heat transfer between hydrogen and the inner wall, heat conduction through the tank wall, and natural convection of the outer wall. Prediction values of temperature, hydrogen charge amountm and heat transfer to the outside were calculated. Additionally, by investigating the performance of the hydrogen refueling station heat exchanger, the heat of the heat exchanger needed to keep the hydrogen temperature within a safe range was calculated. Due to the Joule–Thomson effect, the hydrogen temperature passing through the pressure reducing valve changed, and the changed value in the hydrogen charging cycle was predicted and calculated by calculating the temperature change value at this time. This study provides a theoretical research basis for high-pressure hydrogen energy storage and hydrogenation technology.

Keywords

• compressed hydrogen storage
• heat and mass transfer
• thermo-mechanical
• heat exchanger
• pressure reducing valve