Characteristics of CFRP Hydrogen Storage Vessel on Rising Temperature in the Filling Process

Abstract

Different types of materials are commonly used for constructing hydrogen pressure vessels. However, carbon fiber reinforced plastic (CFRP) materials are commercially used in hydrogen vessels now a day. Commercially used aluminium liner vessel is easy to construct and posses high thermal conductivity compared to other commercially available vessels. However, compared to CFRP liner vessel, it has low strength capacity and safety factors. Therefore, now a day, CFRP liner vessels are becoming more popular in modern hydrogen vehicle systems. Moreover, CFRP vessel has light weight advantage. CFRP, although, has many desirable properties in reducing the weight and in increasing the strength, it is also necessary to keep the material temperature below 85C for maintaining stringent safety requirements. Because while filling process occurs, the temperature can be exceeded due to the compression works of the gas flow. Therefore, it is very important to optimize the hydrogen filling system for avoiding temperature rise to cross the critical limit of damaging CFRP wall vessel. Computer simulation has been conducted to characterize the CFRP storage vessel in hydrogen filling to optimize the technique. Three hydrogen vessels with different volumes and with different filling pressure have been used to characterize the temperature rise of the wall materials in filling system. The wall materials have been considered as aluminum liner material and CFRP composite materials. Supply tanks have been played important roles in supplying hydrogen in different storage tanks with different supply pressures. Gas temperatures have been measured inside representative vessels in the supply reservoirs and at the inlet to the test tank during filling. In simulation, the geometry has been simplified to a cylinder for illustration purposes. The rise in temperature of the hydrogen and the tank wall during the filling of hydrogen into the actual tank with CFRP liner has been simulated with different filling conditions at Saga University and the results have been compared with JARI (Japan Automobile Research Institute) experimental data as well.