The National Composites Centre has announced that it has successfully tested a range of composite cryogenic storage tanks with liquid hydrogen that it has designed and manufactured. Considered one of the first composite cryogenic hydrogen storage tanks that has been designed, built and tested in the UK, this forms part of the company’s journey in developing expertise in this area, to support the UK’s transition to the hydrogen economy.
The results build on previous announcements about NCC’s UK-based composite cryogenic storage tank testing programme, and concepting tools. Composites design expertise is critical to achieving long life cryogenic storage tanks, 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 (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 8 bar, and manufactured using automated fibre placement on-site at the National Composites Centre. 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 1 bar, followed by a single pressure cycle up to 7 bar. The two-piece tank underwent 10 pressure cycles from 0 to 7 bar 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, 1st – 2nd November at the NEC, Birmingham.