A number of OEMs have publicly dedicated to hydrogen combustion engines for future mid-size and heavy gear. However are they market-ready and is the market prepared for them?
Whereas battery expertise and electrification are making market progress as sensible different energy choices for compact development and agriculture autos, the vast majority of producers would seem satisfied hydrogen-fuelled variations of typical engine bases provide the perfect mix of attributes for heavier machines and better energy calls for. However though current years have seen loads of prototype unveilings at commerce exhibitions and press occasions, full market availability and broad business adoption of such energy expertise would seem nonetheless a way off.
Whereas the framework has lengthy been in place to provide, retailer and dispense liquid fuels and electrical energy, growth of the mandatory expertise and infrastructure to do the identical with hydrogen is probably an excellent few steps behind that of the machines that may use the gas. It’s this that will look like what the market must spark demand for hydrogen-fuelled farm and development gear. However is it that easy? What stage are producers at with their machines?
Refuelling growth
Whereas initially trialling hydrogen gas cell expertise to energy a prototype 360-degree excavator, JCB latterly shifted its hydrogen focus to much less advanced and extra responsive hydrogen-fuelled inner combustion engines, with the added advantages of much less cooling demand and much-reduced weight over a battery-based hydrogen gas cell unit. Nicely-established in its dedication to hydrogen engine energy for its bigger autos, having publicly demonstrated backhoe loader and construction-spec telehandler working prototypes, JCB has gone some option to additionally develop the mandatory expertise to help hydrogen-engined autos.
“Our hydrogen engine growth shouldn’t be a conversion, however new combustion expertise,” says Ryan Ballard, engineering director for powertrain at JCB, talking in regards to the firm’s four-cylinder engine that options in these working prototypes, and which was given its standalone world debut ultimately yr’s ConExpo.
“Due to the completely different traits of a fuel gas in comparison with a liquid one, it requires a very completely different low-pressure, low-temperature combustion course of. We’ve developed a particular oil and additive pack that, at low preliminary engine temperatures, traps the water produced as a combustion by-product. Because the engine warms to working temperature, that water then dissipates.
“We’ve additionally developed a high-efficiency turbocharger that forces way more air into the engine than
a regular unit, serving to maximise hydrogen combustion effectivity.”
However whereas the precept of the engine has now been established for a while, the infrastructure required to help it and others prefer it – and the practicalities of fuelling a machine powered by the unit – are one thing JCB has solely addressed extra not too long ago, with the disclosing of its cell hydrogen refueller.
Based mostly on the stretched platform of one in every of its Fastrac 4000-series tractors, the refueller is designed to switch hydrogen gas between on-site bulk storage and hydrogen-powered machines. It options commonplace nozzle expertise for hydrogen gas supply from refueller to machine, and refuelling time is comparable with that required for refilling with diesel, while the unit’s capability provides it the flexibility to offer as much as 16 refills earlier than the unit itself wants replenishing. The corporate suggests this technique will go well with most customers in that it mirrors how they already handle the refuelling necessities of diesel-powered machines.
Manitou prototypes
Amongst different dealing with gear makers, Manitou Group says that, by 2030, low-emissions merchandise – electrical plus hydrogen – will symbolize 43% of its product line. The agency has opened devoted services for hydrogen-powered machine growth and has a hydrogen-powered prototype telehandler – based mostly on an present 18m-reach development machine – in growth, with exams ongoing to ensure vary and reliability in real-life situations, plus element sturdiness. Whereas this preliminary prototype makes use of gas cell expertise, Manitou says it would in the end choose the hydrogen energy system greatest suited to its prospects’ wants.
“We’re finding out all of the hydrogen-related applied sciences based mostly on what customers want,” says Michel Denis, president and CEO of Manitou. “This present prototype is barely step one – a second rotating telehandler prototype can be developed within the coming months.”
To develop an answer suited to full industrialisation, help from public authorities to develop an rising ecosystem is important, emphasises Julien Waechter, Manitou Group vice-president of R&D. “The inexperienced hydrogen sector is steadily turning into extra established with the entry of extra gamers,” he says. “The entire help mechanisms proposed by the completely different governments will encourage the transition to hydrogen, and can velocity up the event of the distribution community and in the end the discount within the utilization prices of our machines utilizing this vitality. Our purpose is to have a 100% hydrogen-powered telehandler available on the market by 2026.”
Whereas JCB has arguably taken a sector lead in hydrogen-engined off-highway car growth, different multinational OEMs are additionally committing severe R&D cash to hydrogen engine autos. Elsewhere within the development sector, Liebherr continues to work on its H964 four-cylinder and H966 six-cylinder engines, the latter having been developed along side the agency’s R 9XX H2 excavator. Sequence manufacturing of its hydrogen engines is anticipated to start in 2025.
Injection challenges
With increased injection strain and the publicity to combustion pressures and temperatures elevating necessities on injector tightness and sturdiness, Liebherr continues to check its H2 gas injectors and full injection techniques for secure and correct direct injection operation. Utilizing a system-oriented method to hydrogen injection, the purpose is to match the efficiency of an H2 DI engine to that of a diesel engine, requiring any system to be able to guaranteeing excessive circulate charges.
As a result of low density of hydrogen fuel, an injector wants massive valve cross-sections. To allow exact management of small portions, the system strain should be regulated with pinpoint accuracy, factors out Liebherr. Within the agency’s hydrogen injection system, that is achieved by way of a fuel quantity management valve, working alongside different pressure- and flow-regulating parts to create a system-oriented method to hydrogen injection. Along with its direct injection actions, Liebherr says it’s working in parallel on consumption manifold injection parts to fulfill completely different engine necessities.
The corporate has been working with Mahle Powertrain to include the latter’s prechamber jet ignition system (MJI), with engine exams displaying that its use can combust the hydrogen/air combine at a excessive compression ratio, maximising the method’s stability and effectivity and enhancing inexperienced hydrogen’s suitability for heavy-duty and off-road purposes.
“The problem is to cease engine knocking and untimely ignition with out lowering the compression ratio and thus effectivity and efficiency yield,” says Mike Bunce, head of analysis for Mahle Powertrain US. “With a purpose to obtain secure operation with a excessive compression ratio while avoiding engine knock and pre-ignition, hydrogen engines should be operated with a considerable amount of air. The vitality from a standard spark plug is inadequate to ignite such a mix. Our Jet Ignition solves the issue by burning a small quantity of an ignitable combination in a prechamber. The ensuing fuel plasma is handed by means of small openings into the primary combustion chamber and, resulting from its excessive vitality content material, quickly and evenly ignites the primary fuel combination. Assessments with Liebherr’s H966 and H964 engines have delivered glorious outcomes when it comes to combustion velocity, efficiency and emissions.”
Indian push
When it comes to agricultural autos, Indian tractor large TAFE used Agritechnica 2023 to mark its broader push into the total western European farm tractor market by unveiling to attendees each battery- and hydrogen-powered developments.
Ravindran Vijayakumar, the corporate’s chief engineer, has revealed that the modified Simpson engine within the tractor produces 55hp/41kW from its three cylinders, however has additionally said that little additional info can be accessible till additional growth had been carried out.
“It is a fully-working prototype, and we all know we are able to carry ample gas for lengthy working durations, with our design engineers having included appreciable gas storage functionality into the tractor by means of purpose-designed tanks behind the operator’s seat and beneath the platform flooring,” says Vijayakumar. “That can be one of the vital essential elements of machine acceptance. A tractor with this gas kind could be focused initially at markets with the infrastructure to help it, which is why we’re making a concerted push into western Europe.”
When it comes to companies centered solely on manufacturing engines for OEMs, Antonio Leitao, vice-president of off-highway engine enterprise at Cummins, additionally used Agritechnica to underline the corporate’s dedication to hydrogen as a gas for the event of future sustainable drivetrains. By creating options aligned with present car designs, the corporate is ready to minimise complexity for OEMs and end-users, whereas utilizing a foundation of present parts the place potential offers the maker with economies of scale potentialities and prospects with reliability and sturdiness equal to diesel.
“Hydrogen-fuelled inner combustion engines can meet the calls for of essentially the most difficult purposes, offering the robustness corresponding to a diesel engine to fulfill agriculture’s excessive working and environmental situations,” says Leitao. “The first distinction is within the machine’s on-board gas storage. Via our three way partnership with NPROXX, a specialist in excessive strain hydrogen storage for each stationary and cell purposes, we’re working to help OEMs with the event of storage tanks offering as much as 700-bar strain functionality to maximise capability.”
Solely ag
With a most energy score of 290hp (216kW) and 1,200Nm peak, Cummins says its B6.7H hydrogen engine is aimed squarely on the calls for of agricultural tractors and different machines. Based mostly on a next-generation Stage VI/Tier 5 platform, the engine’s base is unchanged from the six-cylinder block on the agency’s commonplace B6.7. Cummins calls the engine’s design ‘agnostic’, that means it permits constant mounting/area declare for clear diesel, pure fuel or hydrogen fuelling infrastructure, and it’s the cylinder head and gas system which are chief variations.
“We consider hydrogen gas cells can provide an environment friendly energy resolution for heavy-duty purposes with excessive utilisation and vitality calls for, whereas assembly zero-emission wants, working alongside battery expertise – ultra-capacitors, lithium-ion, or lead-acid – in a parallel hybrid set-up to ship instantaneous response,” says Leitao. “We see hydrogen engines and gas cells as complementary energy sources providing completely different choices to prospects relying on the place they’re on their path to zero carbon. Introducing hydrogen engines out there can even speed up the expansion of hydrogen infrastructure to help the widespread adoption of gas cell powertrains.”
This text first appeared within the June version of iVT Worldwide – https://ivt.mydigitalpublication.co.uk/june-july-2024
