TOYOTA Australia has introduced its place as a key participant within the growth of scorching hydrogen – or hydrogen inner combustion – expertise for a future vary of bigger SUVs, four-wheel drives and utility autos, starting with the HiAce Commuter bus.
Below Toyota’s said multi-pronged technique to decrease CO2 emissions throughout its fleet, the Japanese large is investing in a variety of driveline applied sciences together with gas cell hydrogen, hydrogen inner combustion, battery electrical, hybrid, and cleaner-burning inner combustion engines with and with out gentle hybrid help.
However it’s the advantages to not solely the planet, but additionally Toyota’s backside line, that kind an fascinating a part of the recent hydrogen push.
Improvement and tooling prices related to hydrogen inner combustion engines are just about nil, the changeover from petrol to hydrogen being comparatively simple and relevant to each naturally aspirated and compelled induction engines with little modification.
As well as, the thermal effectivity of a spark ignition scorching hydrogen engine is just like that of a compression ignition diesel unit.
Scorching hydrogen might be utilized in a hybridised association to leverage current electrification expertise, a bonus for Toyota because the world’s largest producer of hybrid drivetrains.
The absence of carbon means nearly no CO2 (carbon dioxide), CO (carbon monoxide) or HC (hydrocarbon) emissions are produced from a scorching hydrogen engine.
Nonetheless, dangerous oxides of nitrogen (NOx) emissions might be excessive when scorching hydrogen engines are tuned to ship equal efficiency to the petrol models on which they’re primarily based.
As soon as NOx emissions are addressed – Toyota is engaged on this – scorching hydrogen can yield intensive provide chain, analysis and growth, and manufacturing value benefits.
These are along with the environmental advantages related to hydrogen combustion – supplied ample portions of this gas might be sustainably produced and not using a carbon footprint or inflicting different ecological hurt.
Understanding the expertise
Toyota has intensive expertise in hydrogen gas cell electrical automobile (FCEV) expertise, with memorable previous examples together with the RAV4 (1996), Kluger (2001), High quality collection ideas (2003-05), and FCV-R (2011) and FCV ideas, which finally turned the Mirai FCEV now obtainable in its second era in chosen markets.
There may be even a HiLux hydrogen FCEV prototype doing the rounds within the UK, operating on a modified model of the Mirai’s powertrain.
However you will need to perceive the variations between FCEV expertise, the place a gas cell makes use of hydrogen electrochemically to supply electrical energy (chilly hydrogen), and inner combustion (scorching hydrogen) expertise as demonstrated within the HiAce Commuter H2.
Scorching hydrogen makes use of an inner combustion (spark ignition) engine transformed to run on hydrogen as an alternative of petrol. It’s a surprisingly previous expertise that has been tried by a number of producers again so far as 1806 and one which improves the thermal effectivity of a spark ignition petrol engine to ranges approaching that of a compression ignition diesel engine.
Based on Toyota Powertrain and Business Car chief engineer Takaaki Nakazono, Toyota is working to attain related outputs from the HiAce Commuter’s hydrogen combustion engine as these developed by the 305kW/650Nm V35A-series petrol on which it’s primarily based.
Mr Nakazono was one of many lead engineers tasked with growth of the three.5-litre V35A-FTS engine – discovered beneath the bonnet of the LandCruiser 300 Collection and others in abroad markets – and is at present creating hydrogen combustion expertise to be used on this utility, and others.
He defined that these days, the H2-ICE association permits an output of solely 120kW and 354Nm whereas assembly emissions requirements.
Nonetheless, Mr Nakazono says exhaust expertise at present beneath growth will permit a richer gas/air combination to extract energy and torque figures nearer to these of the twin-turbocharged petrol – a further 185kW and 296Nm – within the very close to future, all whereas sustaining the hydrogen unit’s superior thermal effectivity statistics.
“The thermal effectivity ranges of the combustion hydrogen engine are similar to these of a diesel engine,” Mr Nakazono informed GoAuto.
“If we examine a Mirai FCEV and the HiAce hydrogen engine and contemplating the scale of the FCEV models and the scale of the combustion engine, when producing round 90 kilowatts or extra of vitality, the thermal effectivity between the FCEV and the hydrogen combustion engine will swap.”
Mr Nakazono’s Australian colleague and senior supervisor of car evaluations and laws for Toyota Australia, Ray Munday, stated it was vital to notice that effectivity beneath load was a important advantage of H2-ICE expertise, underlining the significance in delivering diesel-like drivability from the HiAce Commuter H2 prototype.
“Effectivity beneath load is a important level. With electrical motors and different factors (inside the FCEV driveline) as you load them extra, their effectivity drops. That’s why with hydrogen combustion expertise, in heavy loading situations, there’s an effectivity benefit,” he said.
Based on an article printed by Australian-founded publication The Dialog, solely 38 per cent of the vitality used to supply inexperienced hydrogen finally ends up turning the wheels of an FCEV.
Conversely, 80 per cent of the vitality generated to cost a BEV finally ends up turning the wheels. Additional, petrol inner combustion engines are at greatest 38 per cent thermally environment friendly and diesel inner combustion engines 42 per cent.
The thermal effectivity of H2-ICE engines is way the identical as their diesel counterparts.
Detailing the rationale behind the decrease output figures of the early prototype, Mr Nakazono stated that exhaust controls, and never engine expertise, is the present sticking level of the expertise.
“There are two choices (to producing extra energy and torque). One is to easily make the displacement of the engine greater,” he continued.
“Presently, to adjust to emissions laws, the combustion is a lean burn. With a lean burn system, along with the SCR (exhaust) system that’s used for the diesel engine we will meet emissions laws. However to additional enhance output utilizing the present engine – and meet emissions requirements – a brand new type of emissions management would must be developed.
“We’re already creating such a system, and sooner or later, there’s the potential that we will produce a hydrogen combustion engine with related outputs to a petroleum combustion engine, and whereas sustaining emissions laws.”
However can H2-ICE expertise outpace FCEVs and BEVs?
As for competitor applied sciences, and particularly these being developed by Toyota and others within the battery electrical discipline, Mr Nakazono says the hydrogen choice is ready to nonetheless win out, not less than in sure purposes.
He believes that in regional areas of developed nations, in nations with out ample entry to renewable electrical energy and applicable charging infrastructure, and in bigger automobile purposes, hydrogen combustion expertise very a lot has its place.
“Even after we see renewable electrical energy grow to be way more ample than it’s right now, I imagine that in rural areas, and areas exterior of the metropolitan zones, hydrogen is an efficient choice,” he stated.
“And even when electrical energy is produced from renewables, there’s a sort of peak of when electrical energy might be generated, which implies it’s essential to retailer this vitality for different occasions. It’s right here we imagine hydrogen is an excellent choice.”
Concurring with Mr Nakazono, Toyota Australia’s Ray Munday informed GoAuto it was vital that electrical autos weren’t seen as the reply to the decarbonisation of car fleets in each state of affairs.
“This isn’t simply an Australian growth, however one that can attain world wide. We see that every nation is creating efficiencies (in renewable vitality manufacturing) at completely different charges. We additionally see a rising demand for quicker refill occasions, particularly in heavier utilization purposes. In each circumstances, hydrogen has a bonus (over grid-sourced electrical energy),” he defined.
“For a lot of these shoppers, that is the place we must be proper now. With present battery expertise, that’s a problem we will’t tackle. And naturally, that is altering, it’s altering on a regular basis.
“The price of hydrogen manufacturing is coming down, and clearly that’s a part of the Australian authorities’s nationwide hydrogen technique, it’s for us (Australia) to be a pacesetter on a world scale.”
Curiously, Toyota chief expertise officer, Hiroki Nakajima, informed journalists on the current Japan Mobility Present (Tokyo Motor Present) that one of many failings of the Mirai was that hydrogen refuelling stations are few and much between.
However as he sees it, the expertise has a brighter future in purposes such because the HiAce, and within the industrial sector extra broadly.
“We have now tried Mirai however haven’t been profitable. Hydrogen stations are only a few and tough to grasp (with out better assist for growth of the required infrastructure). This is the reason the Mirai sells solely in small volumes,” he stated.
“For mid-size vans, it’s simpler to ship a refuelling community because the autos are used primarily for A-to-B sort journeys. Big numbers of vans go from A-to-B, so you possibly can function stations with extra stability.
“Business autos are crucial space to attempt to proceed with hydrogen,” he emphasised.
Based on US publication Hydrogen Perception, Mr Nakajima stated Toyota would proceed to analysis and develop hydrogen gas cell expertise to be used in vehicles, however believed it was vital to additionally develop extra compact hydrogen gas tanks and gas cells that would slot in a wider vary of autos.
