Prevention and mitigation of accidents with hydrogen-powered vehicles in tunnels

The specific hazards and associated risks of hydrogen vehicles use in tunnels are largely unknown and thus prevention and mitigation strategies are not developed or validated. Previous activities were mainly focused on the fire scenarios with fossil fuels and did not address the hydrogen specific hazards, like pressure and thermal effects during accidents related with high pressure hydrogen storage. Therefore, Regulations, Codes and Standards (RCS) require a scientifically sound basis for the understanding of relevant safety aspects, validated engineering models and tools for reliable prediction of an accident dynamics in confined space, and development of innovative prevention and mitigation strategies and engineering solutions. The main unresolved safety concerns include but are not limited to: what are requirements to hydrogen-powered vehicles entering confined structures such as tunnels, what are appropriate venting strategies for confined and congested space, what are hydrogen specific prevention and mitigation concepts to efficiently tackle hydrogen dispersion and combustion, would hydrogen pressure and thermal effects impact the integrity of tunnel structures, e.g. concrete spalling, how may an initiating event lead to devastating consequences through the domino effect, and how to prevent catastrophic rupture of a high-pressure hydrogen tank in a fire to eradicate any possibility of devastating blast waves and fireballs in these confined traffic infrastructures, which are generally perceived as hazardous sceneries per se. These knowledge gaps and technological bottlenecks in hydrogen safety hamper the further inherently safer deployment of hydrogen-powered vehicles, and the public acceptance of the technology. The scope of this doctoral study could include: identification and prioritisation of relevant knowledge gaps; performing analytical and numerical studies to close identified knowledge gaps; development of innovative safety strategies and engineering solutions to prevent and mitigate accidents with hydrogen powered vehicles in confined infrastructure, e.g. due to pressure peaking phenomenon in garage-like enclosures; determination of specific hazard and risk relevant parameters; development and validation of novel engineering tools, required for the hazard and associated risk assessment; evaluation of effectiveness of conventional and innovative prevention and mitigation techniques and accident management strategies with respect to the specific hazards implied with hydrogen use in the confined infrastructure, etc. The expected impact of the study could include but is not limited to: validated contemporary models and tools for hydrogen safety engineering and use of hydrogen transport systems in confined environment; deeper knowledge of the underlying physical phenomena; innovative prevention and mitigation strategies; guidelines for inherently safer design and use of hydrogen systems in confined infrastructures; elimination of the possibility of a "spectacular", high consequences tunnel catastrophic accident with serious impact on the public acceptance of hydrogen technologies (the "show stopper"). The study will focus on computational fluid dynamics (CFD) modelling, use of the relevant software (FLUENT, OpenFOAM, etc.), multi-processor Linux-based hardware, etc. The results of this doctoral research will be used in HySAFER's externally funded projects and should be reported at international conferences. Publication of results in peer reviewed journals is expected.

The RI self-assessment of an individual's research projects will mean that the cohort have a high degree of understanding of the potential beneficial impact from their research on the economy, society and the environment. This then places the cohort as the best ambassadors for the CDT, hence most pathways to impact are through the students, facilitated by the CDT.

Industrial impact of this CDT is in working closely together with key industry players across the hydrogen sector, including through co-supervision, mentoring of doctoral students and industry involvement in CDT events. Our industrial stakeholders include those working on hydrogen production (ITM Power, Hydrogen Green Power, Pure Energy) and distribution (Northern Gas, Cadent), storage (Luxfer, Haydale, Far UK), safety (HSL, Shell, ITM Power), low carbon transport (Ulemco, Arcola Energy), heat and power (Bosch, Northern Gas).

Policy impact of the CDT research and other activities will occur through cohort interactions with local authorities (Nottingham City Council) and LEPs (LLEP, D2N2) through the CDT workshops and conference. A CDT in Parliament day will be facilitated by UKHFCA (who have experience in lobbying the government on behalf of their members) and enable the cohort to visit the Parliamentary Office for Science and Technology (POST), BEIS and to meet with local MPs. Through understanding the importance of evidence gathering by Government Departments and the role this has in informing policy, the cohort will be encouraged to take the initiative in submitting evidence to any relevant requests for evidence from POST.

Public impact will be achieved through developing knowledge-supported interest of public in renewable energy in particular the role of hydrogen systems and infrastructure. Special attention will be paid to demonstration of safety solutions to prove that hydrogen is not more or less dangerous compared to other fuels when it is dealt with professionally and systems are engineered properly. The public, who are ultimate beneficiaries of hydrogen technologies, will be engaged through different communication channels and the CDT activities to be aware of our work. We will communicate important conclusions of the CDT research at regional, national, and international events as appropriate.

Socio-economic impact. There are significant socio-economic opportunities, including employment, for hydrogen technologies as the UK moves to low carbon transport, heat and power supply. For the UK to have the opportunity to take an international lead in hydrogen sector we need future innovation leaders. The CDT supported by partners we will create conditions for and exploit the opportunities to maximise socio-economic impact.

Students will be expected in years 3 and 4 to undertake a research visit to an industry partner and/or to undertake a knowledge transfer secondment. It is expected these visits (supported by the CDT) will be a significant benefit to the student's research project through access to industry expertise, exploring the potential impact of their research and will also be a valuable networking experience.