Technical debate on diesel engines

[Did67]

Can we not imagine that the diesel manufacturers are working on exhaust pipes making the diesel less harmful?

It exists, it is the famous FAP (Particulate Filter).

We are well into the subject on Diesel.

Does anyone know the level of filtration reached? or the residual emissions after FAP, compared to a petrol engine of comparable power (which also emits a little - pass a finger in a muffler! or look at the color of the drain oil!) ???

It would be an interesting element of debate.

[it is true that the criticism that we make of Diesel - emission of particles - concerns above all and above all the old generation before direct injection and before FAP ...]

[Gaston]

The FAP stops the largest particles (those which make black smoke) and which represent the majority of the emissions measured in mass, but it lets pass almost all the very fine particles.

The FAP is a bit like the Canada Dry of pollution control: we remove 99% of the particles, but we leave 100% of the most dangerous.

[Did67]

YES.

But the petrol engine is not nickel either !!!

I would like to have a "comparison".

[the petrol engine powered by LPG is infinitely cleaner; my oil is not yet black after 30 km; she still took a little of color, let's be honest ...]

[Gaston]

I would like to have a "comparison".

There are this ADEME study (which dates a little).

For conventional engines with indirect fuel injection
The particles emitted are smaller than Diesel particles. These are almost exclusively nanoparticles with a diameter of less than 50 nm. Some studies also present
particle distributions with a peak centered on 50 to 60 nm, but also particles larger than 100 nm. Their number is two orders of magnitude lower than that of particles
Diesel, when measured at low speed or on standard cycles. Their number can increase sharply depending on wealth, especially at high speed on the highway. Under certain conditions, positive-ignition engines can emit as many particles as diesel engines.
When we study over time the size distribution of the particles emitted by spark-ignition engines, we observe the appearance of very strong concentration peaks, while
this distribution does not change over time for diesel engines. This tends to prove that their mode of formation as well as their composition are different. Also note that, for
with spark-ignition engines, the particle distribution sometimes deviates greatly from the log-normal distribution. The definition of the median diameter then loses its meaning because, in this case,
it is no longer representative of the diameter for which the particles are most numerous in the aerosol.
If we compare the different data in the literature, we find that Diesel vehicles emit on average between 2,4 x 10 ^ 14 and 8 x 10 ^ 13 particles / km, while vehicles with ignition
ordered would be between 1,2 x 10 ^ 14 and 3 x 10 ^ 10 particles / km.

For conventional direct injection petrol engines
The new petrol direct injection engines emit approximately 1 x 10 ^ 5 particles / cm3 at low load and 1 x 10 ^ 7 particles / cm3 at high load. Indeed, the direct injection engines currently envisaged develop two injection strategies: at low load, injection is carried out during the compression phase resulting in very stratified combustion. At higher load, we inject during admission, combustion is therefore more homogeneous. At low load, direct injection engines behave like Diesel engines and particle emissions can reach values ​​identical to those recorded on Diesel vehicles 2,8 x 10 ^ 8 particles / cm3. In addition, their composition approximates the composition of Diesel particles. Their size distribution is centered on 100 nm. These particles are believed to contain a non-
negligible carbon.

[chatelot16]

thank you Gaston for this interesting document

I see there an interesting method of measurement with a kind of electrostatic filter which selects the size of the particles to measure them.

we also see there an electrostatic filter of recycl'air brand: it seems to me a good solution, alas it seems that this company has fallen into oblivion
http://www.lesechos.fr/09/03/2001/LesEc ... a-ales.htm
it must be said that in the document of the ademe they measure an efficiency almost zero recycl'air

[pedrodelavega]

The cars that will make 400 000 km no longer exist on current production lines ...

????? You think ?

I remind : http://www.largus.fr/actualite-automobi ... 62370.html

Hello,

I also allow myself to recall:

Mitsubishi ASX guaranteed 10 years

Kia strikes hard: the 7-year warranty now applies to ALL of its range!

Fiat extends warranty to 8 years

Mazda GarantiePlus: 6 years, unlimited mileage

Hyundai, 5 year warranty for the whole range

Renault Clio 4: 5-year or 100.000 km warranty!

4 year warranty for Alfa Romeo in September

By cons, from memory, I do not remember how long was guaranteed the 2CV, R5, R19, Ford Escort etc ...
I know that at the time, the legal obligation was 1 year.

[Did67]

Do we agree that the majority of "gasoline" engines have indirect gasoline injection (except therefore the TwinAir from FIat or the TSI from VW in particular)?

And so that they are not "that spectacularly better" than the Diesel if I understand correctly ????

The Ademe study does not say if it compares to Diesels with FAP!

For me: draw, center ball, and the same tax for everyone!

[chatelot16]

precisely, indirect injection gasoline is the best to avoid particles, exactly like carburetor but more precise ... it is direct injection gasoline which make particles by imitating diesel

gasoline indirect injection: the gasoline is i njected into the intake pipe, so has time to mix well with the air before burning, exactly as with a fuel ... direct injection, the injector injects into the cylinder like a diesel ... it doesn't leave time to mix ... the increase in pressure in the cylinder is opposed to the vaporization of petrol

we also see in this ADEME report that conventional indirect injection diesel engines can be fine particles: they are not ridiculous at all compared to the much more complicated HDI

I think that the complicated mufflers are not the right solution: an ultra light car with a very small engine will have a positive result just by its low power without breaking the bank in unnecessary complication, and saving a lot of fuel

[Did67]

we also see in this ADEME report that conventional indirect injection diesel engines can be fine particles: they are not ridiculous at all compared to the much more complicated HDI

Diesel ???

The debate seemed to go in the direction "Diesel much worse than gasoline" ... so we must tax.

I discovered that the gasoline engine is not that "clean"! Even if it is more.

But this remains very vague, this report!

[Macro]

Frankly in piloted ignition engine ... LPG probably remains the means to have very simply an engine with less pollution ... CNG for all would be a huge step ... without FAP, without catalyst and other fuel eater ...

As far as diesel is concerned, their performance and driving pleasure have increased so much compared to current (European) petrol engines that many (me first) will be reluctant to part with it to take up a petrol chasm. .