With the impending ban on new gasoline and diesel cars and heavy-duty vehicles, construction machinery maker and accomplished innovator JCB believes the writing is on the wall for diesel in factory machinery as well.
There is a common misconception that the impending sales bans apply globally to the internal combustion engine, but this is not the case. That is why JCB is convinced that the switch to hydrogen engines is the way forward for its machines over five tonnes.
The British company’s philosophy is simple: the easiest way to achieve zero carbon is to have no carbon in the fuel. Engineers have reached a stage where they are convinced that zero tailpipe emissions are achievable, so no CO2, no HC and no NOx, just electricity, water and heat. One of the biggest challenges they face, in fact, is figuring out what to do with water emissions.
Why hydrogen? JCB makes award-winning smaller electric machines, but for larger machines it has unequivocally established that batteries will not work due to cost, weight and charging time, whereas construction machines often have to work in continuous to earn a living. It also developed a fully operational 20-ton fuel cell excavator, demonstrating that in addition to being expensive, fuel cell powertrains are not yet rugged enough for the rigors of a construction environment. .
The latest supercharging, direct injection and spark ignition technologies make hydrogen so efficient in combustion engines today that the spectrum of NOx can become insignificant. Prototypes of hydrogen engines are based on the JCB 448, a 4.8-liter four-cylinder that is new from the cylinder head. The direct hydrogen injectors are mounted in the center and there is a new fuel rail that carries compressed hydrogen to them and a larger variable geometry turbocharger. Hydrogen can run much leaner than gasoline or diesel, and it burns reliably at a 100: 1 air / fuel ratio. In contrast, gasoline engines struggle when the mixture leans, to the point of failing the ignition.
Why is this important? NOx is produced at high temperatures, so the leaner the hydrogen is in combustion, the cooler the combustion and the lower the NOx. The combustion chamber hot spots are generators of NOx with any fuel, and JCB is working with experts from the Technical University of Aachen to perfect the mixing of hydrogen and gas. air, drawing on their skills in computational fluid dynamics (CFD).
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This notice was published: 2021-08-15 23:01:24