The influence of thermal conductivity on fire resistance of compressed hydrogen storage systems (CHSS)
The basic research issue in the presented study is to present the influence of thermal conductivity on fire resistance of compressed hydrogen storage systems. Fire resistance testing of hydrogen tanks is performed based on procedures and requirements formulated in the ECE R134 regulation. The fire test consists in exposing tanks or complete systems intended for hydrogen storage in vehicles to an open flame. The essence of this type of research focuses on minimizing the risk of a tank explosion during, for example, a vehicle fire. The main risk factors in this case are high pressure and flammability of the stored gaseous fuel, which is hydrogen. Current CHSS are characterized by a nominal working pressure in the range of 35-70 MPa. Based on the results of the conducted tests, connections were observed between the type of tank, which results from the type of construction materials, and the effects of open flame. One of the key parameters is the thermal conductivity of the tank walls. Its level translates directly into the increase in internal pressure. In composite tanks (Type III and IV), a significant problem is also the degradation of the composite at high temperature, which leads to a weakening of the mechanical strength of the entire structure. Based on the test results, the transfer of thermal energy in the tested tanks was determined. The analyses performed allowed to determine the thermal conductivity and its effect on the rate of pressure increase in the tank and the resistance of its structure to open fire. The summary also explains the importance of these parameters in relation to the arrangement and activation of tank protection elements. In modern CHSS, the basic protection is thermally activated devices (TPRD).
Topic: Sustainability and global trends in powertrain technology
Author: Grzegorz Kubica
Co-authors: Paweł Marzec
