ENEA activities in fuel-cell-powered vehicles: Pressure vessels testing

Among the research and development subjects of ENEA (Italian National Agency for New Technology, Energy and Environment) an important theme is the study of innovative vehicles with high energy efficiency and low emissions. Our programs are aimed at designing and setting up innovative vehicles with electric propulsion. These vehicles will be of two main types: battery-powered (pure- electric) and hybrid (fuel cell/battery and diesel/battery). At the moment, the fuel-cell technology applied to engines for vehicular applications displays broad margins of convenience over any known alternative engine for what concerns the compliance with any present and foreseeable environmental and energy saving regulations. On the other hand, the use of hydrogen, produced on board from fuels or stored as a liquid or a gas, raises new problems from the point of view of safety regulations and standards both in the design and use of vehicles and in the fuel production and distribution. The paper describes the regulations and standards holding in the field of on-board pressure equipment and reports the ongoing ENEA''s experimental activities in the field of fiber-reinforced pressure vessels for on-board hydrogen storage. A working program was financed in April 1997 by Ministry of Industry and a working group, composed by ENEA, Istituto Italiano della Saldatura and Italian Department of Transport, was established with the aim of to keep the technical aspects of testing and to get licensing of these components. Non-destructive and destructive testing have been completed on a batch of 8 all-composite ANSI/AGA NGV2-4 tanks, comprising ultrasonic and radiographic test, ambient temperature cycling, helium permeation test, etc.