Originally posted by antmnte
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Originally posted by joebogey View Post
Finally, the urea (35% in deionized water) reacts with the NOx in the exhaust to cause a chemical reaction to produce Nitrogen and and H2O. Saying it's cow piss in the tank is like saying you wrap your sandwich in crude oil because you use plastic wrap.
A bit of Diesel education. Compared to an Otto-cycle engine, Diesels make little unburned HC and not much CO and they can be eliminated with a fairly conventional catalyst. The particulate matter can be cleaned up easily with a Diesel particulate filter (DPF) - these have been in use for many years and you've seen them at an indoor tractor pull on the tractor that pulls back the sled (otherwise the arena gets filled with smoke). The cat and the DPF can easily be combined and in fact they work better when they are.
NoX is made in large quantities in a Diesel and it's the hard one to reduce. NoX is generated as a result of high combustion chamber temps, pressure, and time. Diesels have lots of temp and pressure and relatively lots of time given the slow engine RPMs so they make lots of NoX. EGR helps, especially when it's cooled. But to get it to "safe" levels (always an argument about what's "safe") requires some sort of aftertreatment. Diesel NoX does not catalyze (that is, convert to benign substances when exposed to certain noble metals - I don't know why Otto cycle NoX does and Diesel NoX doesn't) so the best way to handle it (given current technology) is to hold it and regenerate the holding medium. The best technology available today is the adsorber - an aBsorber holds the controlled substance in the pores of the substrate while and aDsorber holds it on the surface. Anyhow, it has to be cleaned off with catalytic action and that can be triggered with either Diesel fuel or urea.
There - wasn't that simple!? I spent WAY too many years of my life messing with this stuff.
DanLast edited by DanStokes; April 2, 2013, 06:16 AM.
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Originally posted by DanStokes View PostJoe's got it. The urea goes thru the NoX adsorber and causes a catalytic reaction so what leaves the adsorber has nothing to do with the urea (or Diesel fuel) that went in. The whole point of the NoX regeneration is to turn whatever is on the surface of the adsorber into benign components (N2 and H2O). This clears off the surface of the adsorber so it can grab whatever comes down the pipe next.
A bit of Diesel education. Compared to an Otto-cycle engine, Diesels make little unburned HC and not much CO and they can be eliminated with a fairly conventional catalyst. The particulate matter can be cleaned up easily with a Diesel particulate filter (DPF) - these have been in use for many years and you've seen them at an indoor tractor pull on the tractor that pulls back the sled (otherwise the arena gets filled with smoke). The cat and the DPF can easily be combined and in fact they work better when they are.
NoX is made in large quantities in a Diesel and it's the hard one to reduce. NoX is generated as a result of high combustion chamber temps, pressure, and time. Diesels have lots of temp and pressure and relatively lots of time given the slow engine RPMs so they make lots of NoX. EGR helps, especially when it's cooled. But to get it to "safe" levels (always an argument about what's "safe") requires some sort of aftertreatment. Diesel NoX does not catalyze (that is, convert to benign substances when exposed to certain noble metals - I don't know why Otto cycle NoX does and Diesel NoX doesn't) so the best way to handle it (given current technology) is to hold it and regenerate the holding medium. The best technology available today is the adsorber - an aBsorber holds the controlled substance in the pores of the substrate while and aDsorber holds it on the surface. Anyhow, it has to be cleaned off with catalytic action and that can be triggered with either Diesel fuel or urea.
There - wasn't that simple!? I spent WAY too many years of my life messing with this stuff.
Dan
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Originally posted by SpiderGearsMan View Postif I was just a customer ...I would buy a d max ....but they are more trouble than gas engines and everything costs a lot more
thanks to the nanny state ...there are no gas big blocksLast edited by TC; April 2, 2013, 07:36 AM.
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Originally posted by TC View PostDan can you explain what Opacity is??, that is what the Emissions people here test Diesel for........Escaped on a technicality.
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Originally posted by TheSilverBuick View PostIt's a measure of the particulates (black stuff) that are coming out of the tail pipe. Even when you can't see it a calibrated light or laser can measure the particulates and check the opacity of the exhaust. With the new'ish NOx controls, it won't be long before places like CA start measuring NOx on diesels like they do cars, if they don't already.
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I'm somewhat impressed by the new TDI engine, too bad the car around it and their dealerships here Suck it. I didn't care for the ergo in a VW. The dealers ... we won't go there.
I might check into the Cruz if it's not too $$$.Flying south, with a flock of bird dogs.
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Originally posted by TC View PostSpraying piss into the exhaust system in order to clean up emissions is a waste of time...... Just more crap to break down......
So yeah, wrong, the DEF fluid systems are a LOT less complicated than the DPF systems that are on their way out. That's why the manufacturers are all moving to the fluid instead of the systems that are dry or use diesel.
And it's not "piss" - it's got Uric Acid in it, and piss has "Urea" in it, but they are not the same.
I have been getting massive doses of Diesel, Gasoline, and Gaseous Fuel emissions regulations and tuning lately, as I am working for a company who makes (among other things) stationary engines some of which must comply with the rules. The bottom line in this country is, the powers that be do NOT want us moving to Diesel like Europe did, so they're making it very cost prohibitive to use anything that runs on diesel fuel.www.realtuners.com - catch the RealTuners Radio Podcast on Youtube, Facebook, iTunes, and anywhere else podcasts are distributed!
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Originally posted by milner351 View PostJim - GM killed the 8.1? I thought you could still get that in the over 8500gvw stuff?
The Ford V10 lives on - but only in the Econoline heavies.www.realtuners.com - catch the RealTuners Radio Podcast on Youtube, Facebook, iTunes, and anywhere else podcasts are distributed!
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I am into diesels, but learned more facts on the net than real world. it all changed very fast in trucking from the 80s to today..
did you know diesel is 14.5 to 1 to be exact stoich, gas is 14.7..
and diesel spits black when you have it "correct".
the hog is gasoline.
as soon as the black hits the air, it does go away. I believe a sequential turbo setup like in the modern 550 cat is plenty smart enough. Never see stuff flying.
the dpf and piss stuff is insanely retarded.. they are not thinking enough of the natural process to make it invisible.Previously boxer3main
the death rate and fairy tales cannot kill the nature left behind.
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