Hydrogen Jet Ignition - a pragmatic approach to zero engine out emissions in future heavy duty vehicles
Lead Research Organisation:
University of Nottingham
Department Name: Faculty of Engineering
Abstract
Traditional heavy duty IC engines utilise liquid or gaseous hydrocarbon fuels, with only c.35% of the energy in the fuel converted in to useful work. The by-products of combustion include soot and NOx, both harmful to health. Significant attention is now being paid to zero tailpipe emission electric vehicles. However, recent life cycle analysis has shown it can take up to 10 years to break even in terms of equivalent CO2 to a modern diesel engine in a family sized passenger car (with considerable CO2 associated with battery production). The IC engine costs approximately 10% the capital cost of an electric powertrain for such a passenger car. In trucks the outlook is staggering, with battery costs of several hundreds of thousands of US dollars in the Tesla Semi. Fuel cells provide an alternative but cannot yet sustain the required degree of transient operation.
We propose a radical new solution that involves the use of a new type of IC engine combustion system fuelled with hydrogen and capable of converting over 50% of the energy in the fuel in to useful work. The combustion system is based upon an insulated turbulent pre-chamber independently fuelled with hydrogen. When fuelled with fast burning hydrogen (fast even under ultra lean conditions) this system can result in zero tailpipe emissions of NOx and soot under all conditions. An illustration of the combustion system is shown. The reaction jets enable increased flame area and hence rapid combustion under ultra lean fuel conditions. The hydrogen can either be stored directly on-board or reformed from hydrogen-rich carriers, e.g. liquefied synthetic-fuels or ammonia, with the 'cold energy' of the liquefied fuel recaptured to further improve engine cycle thermal efficiency. Compared to fuel cell electric vehicles the system can be operated under more transient driving conditions (one of the remaining stumbling blocks to fuel cells). Simpler pre-chambers are currently used in Formula 1 without a separate fuel injector in the pre-chamber (meaning the fuelling rates in the pre and main chambers cannot be independently optimised, which is key to ultra lean and high efficiency operation). When coupled to exhaust heat recovery we believe an overall powertrain efficiency of 55-60% will be feasible, which is competitive with fuel cell efficiency for significantly lower cost.
We propose a radical new solution that involves the use of a new type of IC engine combustion system fuelled with hydrogen and capable of converting over 50% of the energy in the fuel in to useful work. The combustion system is based upon an insulated turbulent pre-chamber independently fuelled with hydrogen. When fuelled with fast burning hydrogen (fast even under ultra lean conditions) this system can result in zero tailpipe emissions of NOx and soot under all conditions. An illustration of the combustion system is shown. The reaction jets enable increased flame area and hence rapid combustion under ultra lean fuel conditions. The hydrogen can either be stored directly on-board or reformed from hydrogen-rich carriers, e.g. liquefied synthetic-fuels or ammonia, with the 'cold energy' of the liquefied fuel recaptured to further improve engine cycle thermal efficiency. Compared to fuel cell electric vehicles the system can be operated under more transient driving conditions (one of the remaining stumbling blocks to fuel cells). Simpler pre-chambers are currently used in Formula 1 without a separate fuel injector in the pre-chamber (meaning the fuelling rates in the pre and main chambers cannot be independently optimised, which is key to ultra lean and high efficiency operation). When coupled to exhaust heat recovery we believe an overall powertrain efficiency of 55-60% will be feasible, which is competitive with fuel cell efficiency for significantly lower cost.
Planned Impact
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.
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.
