An all-composite CNG tank consists of a one-liner wrapped in the hoop and longitudinal direction with structural carbon filaments. To allow labeling and to offer better protection of the external surface, a protective layer with glass fiber reinforcing is added. In this particular project, a thermoset matrix was used. The use of an all-composite tank reduces the weight of tanks from 400 kg (steel tanks) to 40 kg but also requires regular inspection.
Aim of monitoring:
The ZEM project addresses the development of a monitoring system to verify the integrity of composite high-pressure tanks for natural gas or hydrogen. Stationary and mobile applications are considered and a demonstrator related to vehicle propulsion will be developed. Currently, proposed inspection techniques for composite vessels involve off-vehicle visual inspection and pressure testing which is labor-intensive and requires expensive equipment. The proposed approach, based on fiber optic sensors, facilitates a simple but detailed evaluation of the structural integrity, monitored online during tank refueling. The aims are to eliminate the requirement for periodical inspection through different levels of monitoring on-board, at the refilling station, and in the garage. The project focuses on particular fiber optic sensors and their embedding in the material, composite tank manufacturing, signature recognition algorithms, and interrogation methods. The sensors are embedded between the last carbon layer and protection layer, and the SOFO system was used.
|INSTALLATION PERIOD||TYPE OF SENSORS|
|2001 – 2004||SOFO|
Current status: Sensor based on SOFO technology, embeddable in composite material successfully developed, applied, and tested. Sensor topologies for damage detection were successfully developed and tested. Algorithms for damage assessment were successfully developed and tested.