Particulate Filters for Gasoline Direct Injection Engines?

[jus2shy]

One of the proposed approaches of handling particulate matter from a GDI motor: SAE Article on GDI.

Some interesting notes.

• Looks like Audi will join the ranks of Toyota in implementing a port and direct injection setup to help aid in reducing soot emissions (probably with the added side effect of washing the backs of the intake valves as well).
  
• Particulate filters are also noted as a possible way to curb soot emissions.
  
• Also seems like they're looking to higher injection pressures and increasing fuel atomization, getting the injection scheme closer to that of diesels. I have to wonder how that will work with a fuel that has even less lubricating properties than Diesel. Hopefully they don't use the CP4 as a springboard for designing a new injection system 😉

The 2017-2022 time period will be interesting in the world of the Internal Combustion Engine (gasoline specifically).

[DirtyOil]

GDICI is also in the works and beyond the proof of concept stages

Another potential is vaporizing the gasoline just before DI, but the pressures
involved 'almost' phase changes it back into a liquid...that is where tons of
patents *WILL* be

My bet is in pre-chambers. Either or for both liquid gasoline and vaporized gas

Current prototypes of GDICI has exhaust particulates and NOx in the same realm
of diesel

Think this poster meant GDCI not GDICI, nice idea, but like GMs HCCI cold weather/temperature will most likely send it back to the drawing board.

Currently, the Fed's have grants for sewage treatment plants in the Continental USA
for flare off gases to be converted into LNG for automotive use. I'm not a fan
of that, yet. My work in solid state compressors beats all of the piston compressors
both in efficiency and longevity. My city's PW's has an approx $2.5M grant just
for that, but am skeptical of how many gallons per day, vs the city fleet and
the ROI of such a venture

for a moment thought you were talking stereo equipment... we went from talking Direct Injection to Music... but then figured you were talking about FRICK Screw Compressors and their patented "Solid State Compressor - control system" (patented in 1978). Screw compressors used in the oil/gas industry are used as "booster compressors" pulling field pressure down to close to a vacuum and supplying a higher suction pressure for reciprocating gas compressors. Depending on how sets up are done, screw compressor can be very efficient or be power hogs. Hardly a "new" development as screw compressors have been used for years. As for Frick's Solid State Compressor - control systems, there are much cheaper systems that can be programmed to suit any end users process.

[DirtyOil]

double post ...oops!

[NinerBikes]

Larger displacement will also deal with more parasitic friction losses. Can't have it any other way. More pistons = more displacement = less stress per bore and also added friction per bore.

Higher stress motors will work, with added work and engineeering in tribology/oils and their additives, and with better, newer materials/alloys and metallurgy to handle additional loads. But it's going to take time, failures, and lots and lots of beta tester miles before the bugs all get worked out, me thinks. Will reference fuel be an issue again in fuel pump designs? 😉

Bosch has backed off on the pressures the CP4 series of HPFP's operate at, letting exhaust treatment do the additional clean up. They have also, in some cases, gone to a smaller bore and a longer stroke to make the fuel volume per injection cycle on their CP4 series pump, effective in 2012 in the VW passat CKRA motor, also went with less expensive solenoid injectors, versus ceramic piezo injectors, that can crack and contaminate the fuel, like in when bleeding fuel lines on the high pressure side. Another reason to not run your diesel with HPFP out of fuel or get down less than 1/4 tank of fuel in the tank, taking on air and cavitating is bad bad juju for these pumps.

All of this translates to the V6 TDI motors in VW Touaregs, Audi Q7's and Porsche Cayennes series of tow vehicles in diesel, as well as the European V8 4.2 TDI not seen state side, or the monster V-12 they shoehorned into an Audi Q7 out of their 24 hr LeMans/ 12 hrs Sebring racing series motor. So the technology does flow down from racing.

[BenK]

The most efficient ICE is a 2 cycle diesel at 40%. Meaning that 60%
is lost/wasted through heat rejection...which also says there is that
much more that 'might' be gained with technology yet to be discovered
for both gasoline and diesel. This then means gasoline is even less
efficient with more potential to capture that goes down the tail pipe
or radiated

SMOG for diesels was coming, but the very large increase in the numbers
buying helped accelerate the SMOG'ing of diesels

As for the particulate issue with GDI...it has to do with the zones of
extremely rich...to stoichiometric...to ultra lean. Propagating from
the nozzle. Same thing for diesel's

It is in the extremely rich zone that most of the particulates form and
the work is in ever smaller droplets. Why say it is moving towards vapor
and HOW2 turn liquid into vapor at that point.

The extremely high PSI's is to get the GPH through these tiny, tiny
nozzles...at the cycle rates needed for an ICE

There is also work with multi squirts. Initial very small to ever larger
The issue is cycle rates of the nozzles and the ability to meter small
enough of a squirt

The whole fuel system is now going to be tested on its longevity and
IMHO, tens to hundreds of millions of miles needed to get a proper
picture. Solid state injectors has a shock from closing and am looking
for info on that topic

Microwave has been tried and the images of the magnetron is HUGE
for each nozzle and think a central with distribution, but that brings
up more issues than it solves. Didn't work that well in the lab either

Lasers kinda sorta works, but the optics become a maintenance nightmare

Back to the secondary port injector and the denotation issues. Any
port injector has to squirt just before and during the intake valve
opening.

That then has fuel in the manifold and potential for denotation inside
the CC. Therefore, the compression ratio can NOT be as high as only DI

That then leads to the bottom line for power...PSI on the piston top

Higher compression ratio allows higher potential PSI's. Forced fed
allows for higher PSI's. Timing advance allows for higher PSI's

All of that is dependent on managing denotation and that depends on
the CC's condition before you want the burn event...not detonation...

Larger displacement can have lower PSI's and still have the over all
power. Made up by more square inches of the piston top. This is why I
prefer variable displacement of a larger displacement ICE...which can
always be forced fed

{edit}...Also less stressed than a smaller displacement producing the
same levels of power. The level of stress can be increased for ever
more power on the larger displacement ICE

In a highly stressed ICE...those higher stresses can be addressed much
of what Ford has done with their EcoBoost ICE. Time will tell if they
got all of them controlled. The real test to me...is when the public's
general abuse of their vehicles rears its head and that is down the
road...

[old_guy]

our wonderful all intelligent government at work folks.

[jus2shy]

Fish, have any links to how the 2-stroke system works? Did a quick search, but couldn't find anything too authorative and would rather read something with more technical information on it.

Benk, Interesting comments. In my eyes, I've been thinking super-critical (basically phase change before injection) fuel injection would be the next generation to get rid of the need of a particulate filter (still would need a NOx trap for diesels though. Didn't think about the application towards gas, but that would negate the need for particulate filtering there as well. Also agree the port+GDI approach seems brutish.

2003Silverado and ib, I was surprised to even see the idea of particulate filters for gas engines make it to the stage it's at now. I always thought they would just work with injector nozzles and raise pressures to get closer to diesel injection pressures for better atomization. At least the gas motors would remain a little simpler since I don't think they would need a NOx catalyst. But I'll be watching how these future regulations unfold.

[ib516]

2003silverado wrote:

I, and I think others on this forum have sacrificed the power of the diesels for the simplicity and lower cost of repair of the gas engines. Not trying to start a fight because I know a lot of people with the newer diesels like them better than the trucks of a decade ago, but I don't know anyone that wouldn't rather have the engines today without the emission systems.

I'm in that group.

[2003silverado]

Looks like they are going to make the gas engines too complicated for their own good along with the diesels. Up until 2007 diesels used to be considered the pillars of reliability due to their relative simplicity, mainly due to the lack of an ignition system. Since 2007 diesels have been made more complicated in the name of reduced emissions, and it seems most of the problems with the diesels is due to the emissions systems, or the injection systems that are also designed to reduce emissions.

I, and I think others on this forum have sacrificed the power of the diesels for the simplicity and lower cost of repair of the gas engines. Not trying to start a fight because I know a lot of people with the newer diesels like them better than the trucks of a decade ago, but I don't know anyone that wouldn't rather have the engines today without the emission systems.

[FishOnOne]

jus2shy wrote:
One of the proposed approaches of handling particulate matter from a GDI motor: SAE Article on GDI.

Some interesting notes.

• Looks like Audi will join the ranks of Toyota in implementing a port and direct injection setup to help aid in reducing soot emissions (probably with the added side effect of washing the backs of the intake valves as well).
  
• Particulate filters are also noted as a possible way to curb soot emissions.
  
• Also seems like they're looking to higher injection pressures and increasing fuel atomization, getting the injection scheme closer to that of diesels. I have to wonder how that will work with a fuel that has even less lubricating properties than Diesel. Hopefully they don't use the CP4 as a springboard for designing a new injection system 😉

The 2017-2022 time period will be interesting in the world of the Internal Combustion Engine (gasoline specifically).

Do some research on the direct injected 2 stroke outboard motors if you want some examples of how gasoline can be injected at higher pressures.

[BenK]

GDICI is also in the works and beyond the proof of concept stages

Another potential is vaporizing the gasoline just before DI, but the pressures
involved 'almost' phase changes it back into a liquid...that is where tons of
patents *WILL* be

My bet is in pre-chambers. Either or for both liquid gasoline and vaporized gas

Current prototypes of GDICI has exhaust particulates and NOx in the same realm
of diesel

Currently, the Fed's have grants for sewage treatment plants in the Continental USA
for flare off gases to be converted into LNG for automotive use. I'm not a fan
of that, yet. My work in solid state compressors beats all of the piston compressors
both in efficiency and longevity. My city's PW's has an approx $2.5M grant just
for that, but am skeptical of how many gallons per day, vs the city fleet and
the ROI of such a venture

When was still considering moving to diesel...research found that the next gen
(now the current gen) would have very, very onerous smog controls. Within that,
the discussion of after burners, etc does do the trick on particulates, but the
gases formed were not easily controlled...back to particulate filters, etc

The CP4 has nothing nifty anymore and it's 'main' weakness if that the piston
rod is NOT captured on the cam (crank), nor piston bottom. Another, but not the
only other, weakness is that they used the diesel as the cam/follower/etc lube & coolant

So another piston like pump with a captured piston to rod to crank would be less
likely to have similar issues. A caged desmodromic setup would be way better

Going back to a supplemental port injector kinda sorta defeats one of the key
benefits of GDI and that is no fuel in the manifold...therefore higher
advance without detonation.

All of he papers read up till now, says GDICI works and am hopeful they will
do some work on larger displacement ICE's

Too many look to reduce displacement as the main means of increasing MPG with
a highly stressed, small displacement ICE. I like larger displacement
variable displacement and think the patents have been keeping others
away to stay with the small displacement, but highly stressed

There is yet, another particulate filter, but can't say anything more on that
till they announce. That will work for both gasser and diesel. Of course after
they file and have OEMs lined up for proto's