Day 2, 3rd March 2022
On Day 2 of the Future Propulsion Conference 2022, the Heavy Duty theme continued in the seminar programme, with speakers from Cummins, Ricardo, FEV & Dolphin N2 all taking part in the ‘Hydrogen Combustion’ seminar chaired by Alan Tolley, Advanced Powertrain Technologies Ltd.
Duncan Engham of Cummins opened proceedings with a common theme, that of the inherent challenges posed by the heavy duty/off-highway sector in reducing emissions. One of his questions left a resonance in the air when he questioned what would happen to “legacy fleets after 2050” & questioned if they could they be upgraded or would they simply be retired, adding to the global gathered remnants of former technologies?
Duncan focussed on the need for a reduction in emissions for the heavy duty/off-highway sector, as a fully zero emission status for 40+ tonnes of truck, agriculture or marine would continue to face challenges to reach fully zero emissions immediately, without losing sight of energy efficiency & the wide variety of vehicles challenging the zero emissions targets set globally.
During the event it was discussed often about how the Government & Policy Makers in the UK need to get on the side of heavy duty/off-highway & as Duncan said “we need to get our fingers out of our ears over NOx, when we CAN get zero NOx out of tailpipes” further extolling the energy efficiency of a clean ICE & it’s continued relevance in the heavy duty/off-highway sector.
Nick Owen – Technical Director, Dolphin N2 addressed attendees with the question: “The Recuperated Split Cycle Engine: A Practical Hydrogen Solution for Heavy Duty?”
Nick explored some of the history of Dolphin N2, from it’s establishment in 2017 at Ricardo Plc to the spin-out in 2019 when Dolphin N2 were acquired by FPT Industrial, part of the Iveco Group. Since then, the Dolphin N2 team have grown to a 35 strong staff with sites at Millbrook, Shoreham & testing facilities at the University of Brighton.
Dolphin N2 have had a multi-cylinder prototype of the running engine since December 2020 & the data already looks promising with high thermal efficiency –55-60% BTE, low emissions – NOx at SULEV or below with standard SCR & fuel compatibility with Diesel, Methane & Hydrogen
Nick explained that the Dolphin N2 technology specifically targets heavy duty & the long-haul sectors where most commercial vehicle CO2 originates & alternatives are the most challenging.
The Basic Cycle of the Recuperated Spilt Cycle Engine is made up of: Dedicated Cold & Hot cylinders of unequal size, Insulation of hot cylinder, Recuperation of exhaust energy, Low-NOx Cool Combustion enabled by dense sonic intake air & Cooled Compression.
Although the Dolphin N2 engine & the technology built around it uses the efficiency of a diesel engine as it’s base model, the developments mean that the RSCE can also be run on methane & hydrogen.
Nick asked the rhetorical question, “Why hydrogen?”
Hydrogen is politically favoured as an “alternative to electricity” for an on-highway application as it is already readily produced from renewables, with zero “source to tank” & net GHG (which matters) Hydrogen also produces zero GHG at the tailpipe (politically popular), is fairly quick to refuel – the energy density is acceptable with compromise & it suits both Fuel Cell & ICE – creating critical mass of demand.
The benefits of a Hydrogen ICE are that a Hydrogen ICE works, is fast to adopt, uses the same supply chain as current manufacturers, has familiar servicing needs, NOx is entirely manageable via lean burn & in principle it suits a Recuperated Split Cycle. “Fast oxidation” combustion is fuel agnostic – violent mixing with red-hot sonic & supercritical air will burn many things & if Hydrogen can maintain BOTH high efficiency & low NOx, the advantages are clear.
So how are the low NOx emissions validated with the Split Cycle running on Diesel? Using engine-out emissions (no catalytic after-treatment) a typical modern Diesel truck engine produces 7-10g/kWh & the best Split Cycle results on Diesel were below 1g/kWh EO – SULEV with SCR
Therefore, how does Hydrogen compare? With the operation limited to 20 bar air pressure, to get enough hydrogen in & the energy input limited to 55% hydrogen to keep heat in the process; the same low NOx is readily achieved & no detonation or misfire seen.
Nick concluded his seminar participation by establishing that The Hydrogen ICE is a key enabler for Net Zero because the RSCE offers a step ahead in efficiency with:
Hydrogen ICE as an enabler
- Capable of being clean (local air quality) – including NOx
- Cheap, impurity tolerant, easy to make, integrate to vehicle, and service
Recuperated Split Cycle Engine as a step ahead
- Significant mechanical challenges of the base concept now being overcome
- Low NOx and efficient thermodynamics increasingly demonstrated
- Hypothesis that these can be achieved on any fuel validated with Hydrogen
- Potential to take on the Fuel Cell – or simply help it into the market by justifying fuel infrastructure
Nick Owen finished by sharing the progress thus far & what the next steps are for the Dolphin N2 RSCE. He concluded that in 2022 DolphinN2 would be seeing a Single cylinder testing of a spark-ignited system (limited load) & Testing of HPDI dual fuel (full load range) & by 2023 a full demonstration of the RSCE would be running in a vehicle.
The seminar was incredibly well received, with many more questions being posed about how the Dolphin N2 technology can support the drive towards zero tailpipe emissions for the heavy duty/off-highway & agriculture sectors.
The final keynote was delivered by Selin Tur – Vice President of Advanced Technologies & Innovations, CNH Industrial.
Selin reiterated the inherent challenges facing the reduction of emissions in the heavy duty/off-highway/agriculture & marine sectors. When speaking about the energy inefficiencies already faced by such agricultural machinery as a combine harvester with it only producing 24% efficiency at the powertrain; Selin concluded that diesel is still the most energy efficient form of fuel for these types of vehicles.
With future generations seeking to live in more dense urbanised cityscapes & an ever increasing global population needing an ever increasing amount of food to survive; Selin explored how the autonomous vehicle market was answering the call for work that new generations of workers do not want to undertake.
Selin then focussed on how the acceleration towards net zero could only be achieved along the path of the value chain, with operational costs sometimes outweighing the investment costs.
This is why CNH Industrial are primarily investing in alternative fuels such methane, hydrogen & natural compressed gas; not only for their negative emissions, but also for their ease of delivery in a fuelling infrastructure. With heavy duty agricultural machinery being in situ for days, sometimes weeks & running 24 hours a day, often in entirely remote locations with no access to amenities such as electricity; the fuelling opportunities must be available to move to the vehicle, not the other way around. With this in mind CNH will continue to look at the outcomes & opportunities offered by methane production, within a circular economy, building partnerships along the way to build a sustainable ecosystem.
From a heavy duty perspective, FPC2022 was a breath of fresh air.
With the UK Government focussing on the eradication of petrol & diesel passenger cars & light goods vehicles by 2030, the media mostly sideline the options for the heavy duty sectors, forgetting that it is this sector which still delivers their food & lifestyle necessities hundreds of thousands of miles for their consumption.
Therefore, it was refreshing to hear many attendees, even the electrification industry leaders, acknowledging the challenges facing the heavy duty sector & in particular how technologies such as the Dolphin N2 ThermoPower ™ Recuperated Split Cycle engine can support the transition to zero tailpipe emissions for HGV’s, agricultural machinery, off-highway & marine.
The Future Propulsion Conference was an incredible opportunity for academics, industry leaders & engineers to gather together for the first time in “3D” for what seems like an age & the overwhelming feedback from the event was how successful it was at bringing like minded teams of people together with one ultimate goal; a reduction of tailpipe emissions to reduce the impact of advancing climate change.
Written by Katy-Jane Mason for & on behalf of Dolphin N2