Weichai Power Unveils World’s First Diesel Engine with 53.09% Thermal Efficiency
 

Weichai Power Unveils World’s First Diesel Engine with 53.09% Thermal Efficiency:

"....upgrading from a thermal efficiency level of 45-46% to 53% could enhance diesel engine economy by approximately 14% ... For a heavy-duty tractor traveling 250,000 kilometers annually, this improvement could save roughly 12,000 liters of diesel fuel each year...

...Weichai Power’s research team embarked on a focused effort spanning over 500 days to refine four critical systems: combustion, air intake, fuel delivery, and friction reduction..."
https://baudouin.com/weichai-power-s...ciency-record/

https://en.weichaipower.com/media_ce...20_104523.html

Anyone wondering why I bolded friction reduction. and air intake? :)

Looking at the pictures of the engine in the links I wonder why it has the cooling fan mounted directly on the engine, and not on the radiator?

Unless it so efficient that it can do away with the water-based cooling system?

' 53% BTE '
 

A BSFC map would be instructive, as we could 'see' where the 'island' of lowest fuel consumption occurs, and the rpm bandwidth in which it resides.
For ground transport, road loads are transient, requiring the transmission to keep the engine at the 'sweet-spot,' if operating at 53% BTE is to ever be realized with OTR transport.

So, unless CVTs become a thing on big rigs (some agricultural tractors already resort to it), you think the 53% thermal efficiency claim is only halfway truth?

' CVTs '
 

* According to Ricardo Engineering, a 12-speed transmission has the same mechanical efficiency as a CVT, so that would require a 'doubling' of what is commonly in use.
* The 'formerly most efficient' 'diesel' engines were as the Hitachi units, used for cargo ships. They were 46% BTE, as big as some mobile homes, pistons as tall as an adult male, and operated at a constant 130-rpm, on 'bunker fuel.'
* And presently, Daimler-Benz' Freightliner, diesel-electric hybrid tractor-semitrailer, has a BTE-e of 55%, adding regen into the mix.
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Weichai may have 'achieved' 53% on an engine test-stand, under some arbitrary load constraints, in a laboratory setting.
They need to provide bona fides 'where the rubber meets the road.'
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The engine may have to be made of 'ceramics', with its tribology based upon vapor-phase- lubrication technology, rather than conventional hydrodynamic lubrication, as is the global industry standard.

12 speed? Thats a 4 speed with a 3 ratio brownie behind it. Not all that efficient unless you spend a bunch of time figuring out gearing so that the shift drop puts you into the beginning of the torque curve of that particular engine. Gonna need at least three engine specific transmissions in America.

In Poland, rode a russian made bus that had an 8 forward geared auto. Up to their freeway speeds, all it did was hunt the gears until the bus went steady state on that freeway. 1200rpm climb to 1600, shift, repeat at least 5 more times in the first mile, you're now at 35-40 mph, hard to read the speedo from the first right side seat. 1200 is a bit high for max torque, 1600 is a bit low for max hp. Driver tromps the go pedal, downshifts twice, but not that often because like all pro drivers, the go.pedal has 2conditions: full on, full off. Nicest thing about that russian trans was it didn't shift when you got off the throttle, either up or down.

I'm wondering what the limiting factors are with engineering a Prius-like planetary gear set capable of handling trucking needs? It solves the problem of having too many gears, and the problem of conventional CVT fragility.

Toyota did something like it for some of its hybrid Hino trucks, yet serial hybrid designs have been supposed to be better suited to trucks and buses.


Considering how Toyota matched a scaled-up HSD to an automated-manual transmission for some of its hybrid trucks, most likely trucks would still have more gears than light-duty vehicles.

' torque curve '
 

That's the whole point of the 12-speed.
It's close-ratios, with minimum BSFC 'island-hopping' between gears, allows the engine to remain in it's optimum rpm range of efficiency.
The engines are at, or exceed 1,800-pound-feet of torque, exceeding the capabilities of CVTs when Ricardo did the reporting, hence, the 'conventional' transmission.
Telsa's Semi does an end-run around the issue. It's BSFC-e of 0.135 lbs/ bhp-hr-e, gasoline-e , and 95% BTE-e 'slays' ALL the 'Diesels', hands down. A 'two-fer.'
Also, for dedicated clients, like Frito Lay, where their semi-trailers are only hauling lightweight potato chip-like products, they could operate with dedicated, ' light-weighted' semi-trailers of 'half' the mass, with 'all' the strength necessary, allowing even greater pack capacity, and range, with no weight penalty. ( there's no reason to operate a 'trailer' engineered to carry 'bowling balls', when carrying ' cotton balls'). Adam Smith would 'pity the fool'!