The
National Composites Centre (NCC) in Bristol, an independent, open-access technology centre delivering world-class research and development of composites, has announced that it has successfully tested a range of composite cryogenic storage tanks with liquid hydrogen that it has designed and manufactured in the UK. This forms part of the centre’s journey in developing expertise in this area, to support the UK’s transition to the hydrogen economy.
Composites design expertise is critical to achieving long life cryogenic storage tanks and to overcome some of the potential limitations of composite material formulations. Commercial hydrogen aircraft will need fuel tanks to be as light as possible, filled and emptied numerous times (high cycle), and to last for several decades.
Undertaken with
Filton Systems Engineering Ltd (FSE), the tank-testing programme used a liquid hydrogen vacuum test chamber and cryo-rated testing instrumentation. Tank performance was closely monitored throughout the testing to compare performance against models, with the tanks successfully maintaining full integrity.
Two tanks were tested using liquid hydrogen — one of a single piece construction and one of a split piece design, to assess viability for the design and manufacture of large tanks. The tanks were 30 litres in capacity, designed for a pressure of 8bar, and manufactured using automated fibre placement on-site at the NCC. The tanks comprised only a single skin to contain the liquid hydrogen, and were mounted within a vacuum chamber at FSE’s test facility to provide insulation.
The one-piece tank was subject to 10 thermal cycles of being emptied and re-filled with liquid hydrogen, up to a pressure of 1bar, followed by a single pressure cycle up to 7bar. The two-piece tank underwent 10 pressure cycles from 0 to 7bar at LH2 (-253°C) temperature. The results have enabled model validation, with further cycling scheduled at FSE to test alternative end boss designs using the same composite tank.
Marcus Walls-Bruck, head of hydrogen technologies at the NCC, said: “Our results and novel methods developed will enable rapid advancement within the UK, building fundamental understanding of the challenges in designing and manufacturing cryogenic tanks. This is a significant step forward in the UK goal to develop capability in designing and manufacturing hydrogen powered aircraft of the future.”
The NCC is also developing a ‘state of the art’ manufacturing and test facility for hydrogen transportation and storage, for pressure vessels and pipes, which will underpin its design, test and manufacturing capabilities. With a pressure test system already in place, a Filament Winder and Thermoplastic Pipe Winder will be installed at the facility by the end of 2023.
The NCC Composite Cryogenic Hydrogen Storage Tank has been shortlisted for the ‘Innovation in Design’ category, at the
2023 Composites UK Awards, and will be showcased at
Advanced Engineering (stand T120), being held at the NEC, Birmingham, 1 and 2 November.