Integrated safety strategies for onboard hydrogen storage systems

29889634-fb32-4b3b-9df3-fba931b78f47

Closed

EPSRC
EPSRC
EPSRC
EPSRC
EPSRC

£4,852,565

Oct. 14, 2013

Oct. 14, 2018

This proposal is focused at the main unresolved technological safety issues for hydrogen-powered vehicles, i.e. the fire resistance of onboard hydrogen storage. There are about 15,500 accidental car fires in Great Britain annually (Fire statistics. Great Britain, 2010-2011). The most widespread for car use Type 4 tanks are made of carbon-fibre reinforced polymer (CFRP) and can stand in fire up to 6.5 minutes before catastrophic failure.
To "prevent" catastrophic failure of tank in a fire it is equipped by temperature-activated pressure relief device (TPRD) with currently typical orifice diameter of about 5 mm. A release from 70 MPa storage tank from such TPRD produces a flame of up to 15 m long and separation distance to "no harm" criteria of 70 C of about 50 m. Moreover, due to so-called pressure-peaking effect a typical garage will be destroyed by such a release (about 300-400 g/s) in 1-2 seconds. Use of such onboard storage excludes evacuation of people from the car or safeguarding of people from the car by first responders. To reduce mass flow rate through TPRD and reduce flame jet length would require increased level of fire resistance of Type 4 tanks from today's 1-7 minutes to about or more than 30 minutes.

The project aims to develop novel safety strategies and engineering solutions for onboard storage of hydrogen. This aim will be achieved through realisation of the following objectives (work packages, leading partner is indicated):
- Hazard identification study and risk assessment (Kingston University (KU))
- Critical analysis of current safety strategies and engineering solutions (University of Ulster (UU))
- Numerical parametric study of potential fire attacks from adjacent vehicles (including gasoline vehicles) on road or in car parks (KU).
- Numerical parametric study of conjugate heat transfer from fire to storage tanks of different design and extent of fire protection by CFD technique, including IP of the University of Ulster in the field (UU)
- Parametric finite element analysis to simulate response of tanks of different design to external fire (KU)
- Experimental study of prototype designs to increase fire resistance of onboard storage without and with PRD (UU)
- Numerical simulations to evaluate the reduction in mass flow rate achievable with the proposed increase of cylinder fire resistance (KU).
- Novel storage and safety solutions, including materials for a liner (University of Bath)
- Development of engineering criteria of tank failure to formulate requirements to testing protocol (UU)
- Effect of safety strategies and novel engineering solutions on socio-economical aspects of hydrogen economy (UU).

The research will start with hazard identification study to assess the potential risks involved. Numerical simulations (fire dynamics CFD and structural analysis FEM) will be conducted on the basis of the proposed enhancement of cylinder fire resistance to evaluate the achievable reduction in mass flow rate. Experimental testing will be undertaken for validation of numerical simulations. Based on numerical and experimental studies the testing protocol for fire resistance of onboard storage tanks will be developed. The research will also include the use of materials efficient for hydrogen storage as a tank liner. Socio-economical study will crown the project outputs, translating the engineering safety strategies and solutions, such as higher fire resistance, lower mass flow rate through TPRD, shorter separation distance, provisions of life safety and property protection, into economical equivalents, e.g. cost of land use, insurance cost, etc. The output of this multi-disciplinary project will aim to inform wider public to underpin acceptance of HFC technologies. The project is complimentary to the EPSRC SUPERGEN Hydrogen and Fuel Cells Hub. Collaborators on this project include leading in the field experts and organisations from all over the globe: UK, USA, France, China, Korea.

Potential Impact:
Hydrogen-powered cars and buses are hitting the roads and the full-scale commercialisation is announced for 2015. Safety is a paramount for public acceptance of hydrogen and fuel cell systems. The main unresolved safety issue is low fire resistance of onboard hydrogen storage of only 3.5-6.5 min. This project is focused on the development of safety strategies and engineering solutions for increased fire resistance of storage tanks. The ultimate goal is to provide at least the same level of risk as compared to fossil fuel vehicles. The project outcomes will have economical and societal impact as follows.

- Public will benefit by availability of safer hydrogen-powered transport with risk at least at the same level as fossil fuel vehicles, provisions of life safety and property protection. Inherently safer hydrogen-powered vehicles with increased fire resistance will provide conditions for self-evacuation of a driver and passengers from a burning vehicle, allow rescue operations by first responders, prevent collapse of civil structures like garages in case of hydrogen releases, etc. The project will demonstrate to the public that hydrogen is not more or less dangerous when dealt with professionally.

- Hydrogen industry will benefit by experimentally tested innovative engineering solutions able to improve fire resistance of onboard hydrogen storage drastically with little increase of manufacturing cost. The project results will be commercialised by tank manufacturers, including partners Lincoln Composites (USA) and CEA (France). The European Commission through its Joint Research Centre (Netherlands), overseas partners Zhejiang University (China) and Yonsei University (South Korea) will provide links to other tank manufacturers thus spreading the UK excellence in this field throughout the globe. The impact will be expanded far beyond the project partnership by channelling information on storage systems with improved fire resistance to various networks, including the Industrial Committee of the International Association for Hydrogen Safety, focusing on Daimler, BMW, Hyundai, Toyota, Honda, Kawasaki, Air Products, Air Liquide, ITM Power, Linder Group, Parker Domnick Hunter Ltd, AREVA, etc., industrial members of the UK Hydrogen and Fuel Cell Association, Advisory Board of the EPSRC SUPERGEN Hydrogen and Fuel Cells Hub, etc. The research outcomes will be applicable to CNG/LPG vehicles industry.

- Regulators and standard developing organisations (SDO) will benefit from experimentally validated increased level of fire resistance that can be included into the regulations, developed and tested procedures of bonfire and TPRD testing protocols. This will ultimately benefit public safety and quality of life both in the UK and overseas.

- Academia will benefit from advancing multi-disciplinary research bringing together experts from safety science, computational fluid dynamics, heat and mass transfer, combustion, material science, and economics. Bonfire performance of thermally protected high-pressure tanks with TPRD, including that made of dual-purpose materials, has never been attempted before numerically with the use of finite element and CFD techniques. Experimental program alone will generate a wealth of data and basis for model validations and further research development. The developed and validated state-of-the-art models will be used then as contemporary tools for safety engineering design of competitive hydrogen storage tanks. Outreach activities within European projects with partners involvement, i.e. H2FC European Infrastructure, HyIndoor, HyFacts, HyResponse, will be used to bring together academia and other stakeholders.

The research findings will make a valuable contribution to research-led educational and training programs, e.g. MSc in Hydrogen Safety Engineering and International Short Course and Advanced Research Workshop series "Progress in Hydrogen Safety" at Ulster.