tier 4 locomotive

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tier 4 locomotive
Posted by dh28473 on Sunday, September 17, 2017 9:29 AM

I just want to know what are these locomotives are they very fuel and emission efficent? thanks.

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Posted by NorthWest on Sunday, September 17, 2017 10:29 AM

They are very emissions-efficient but less fuel efficient than the Tier III models.

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Posted by Firelock76 on Sunday, September 17, 2017 12:59 PM

NorthWest

They are very emissions-efficient but less fuel efficient than the Tier III models.

 

Sounds like Tier IV has hit the level of diminishing returns, i.e. less emissions but at the price of lower fuel efficiency. 

Can't have it all, even if some people think you can.

Or, you CAN have it all, you just can't have it all at once.

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Posted by BaltACD on Sunday, September 17, 2017 2:19 PM

Firelock76
 
NorthWest

They are very emissions-efficient but less fuel efficient than the Tier III models. 

Sounds like Tier IV has hit the level of diminishing returns, i.e. less emissions but at the price of lower fuel efficiency. 

Can't have it all, even if some people think you can.

Or, you CAN have it all, you just can't have it all at once.

Recall back in the 70's when emissions first became the issue with automobiles - the engines sucked, sucked down fuel and didn't produce HP.  In the 40 years since understanding and utilization of various technologies have smaller engines with more power and better economy than was ever though possible in the 70's.

I am certain GE & EMD are still working to improve their packages - and I fully expect they will.

         

Never too old to have a happy childhood!

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Posted by Firelock76 on Sunday, September 17, 2017 4:26 PM

Oh, I remember the 70's quite well.  What kind of gas mileage you got depended on the car.  For example, we had a '71 Mercury that was quite economical, around 30 miles per gallon.  A real plus was when you hit the gas the transmission made a sound like like Scotty putting the Starship Enterprise into Warp 9 overdrive!

And, I had a VW Bug, a good 30-plus miles per gallon on that one.

Like my father, I didn't want to put one more cent down the gas tank than I had to, even though in the early '70s gasolene averaged around 23 cents a gallon, pre-oil crisis, mind you.

Muscle cars were a whole 'nother category.  Those things, start the engine and a whirlpool formed in the gas tank! 

Also, keep in mind one of the reasons for better gas mileage in todays cars is the reduction in weight by using more and more plastics and thinner glass.  Ever wonder why windshield replacement seems to be a growing industry?  They're not as thick as they used to be.   

So, it all depends.  Maybe GE and EMD (now Caterpillar) can squeeze a bit more performance out of what they have, but that remains to be seen.

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Posted by Paul of Covington on Sunday, September 17, 2017 5:49 PM

   Ah, Firelock, the early '70's were OK.   Balt is thinking about the later '70's when you had a giant V-8 engine with an air pump to inject air into the catalytic muffler, EGR, and I don't know what else, and got about 8 MPG and would barely move when you floored it.

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Posted by Firelock76 on Sunday, September 17, 2017 6:33 PM

Ah, I see. No wonder the Japanese imports started to make inroads at about the same time.

I never had one of those things you describe.  The first new car Lady F. and myself purchased was a 1980 Chevy Chevette, which was very economical to operate and quite a good car if you took care of it, no matter what you may have heard.  Next was an '84 Cavalier.  We never cared for big cars and always went for the compacts. 

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Posted by Dmacleo on Monday, September 18, 2017 5:42 PM
bingo, prior to thermactor pumps and miles of vacuum hoses and vacuum controlled egr (or the dreaded ford variable venturi carb that worked GREAT for a bit then died...) the large v8 engines could run a high gear (due to torque) and the 3 speed automatics would still get around 20-22mpg. my 2010 marquis with overdrive, lockup converter, and 2.73 rear gears with small (compared to yesteryear) v8 gets 22mpg average.
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Posted by Overmod on Friday, September 22, 2017 1:07 PM

Here's a little additional (until entropy and perhaps some others with distinctive competence add details):

EGR on a locomotive is supposed to do the same thing FGR does for external combustion: displace some of the nitrogen in the charge air with 'spent gas' (largely CO2 and hot water vapor*) so that (1) there is less nitrogen per cycle to react to form NO, etc.  Theoretically, at least, it is still possible (with proper turbocharging) to assure enough oxygen in the intake charge air to give full combustion, in the required time, to the physical fuel charge injected even under full-load conditions when the additional spent gas is added.

Theoretically EGR could provide some measure of performance gains for a different reason (also theoretically associated with multistage turbocharging): some of the waste heat post-turbo in the exhaust can be returned to the combustion cycle and hence 'that much less' fuel needs to be used to get the temperature and thence pressure rise on the power stroke.  In practice, however, there are reasons this is usually "inadequate" (and in the '70s, of course, when turbos were still exotic and highly expensive, adding hot spent gas to a carbureted charge was a formula for bog-slow response and severe limits on developed hp (which of course comes at elevated rpm in most engines, separate from torque peak).

There is also the happy world of 'exhaust recirculation' of things other than spent gas, which Shadow's owner has enlightened us about.  Remains to be seen how troublesome those aspects prove to be ... or how progressive their deleterious effects on performance and thence required throttle setting and fuel burn become.

I do not know if locomotive-sized DPFs have to be regenerated en route or can be serviced by swapping them out, etc.  If the former, expect at least 4-6% of the actual fuel consumption to be "wasted" in regenerating the filter.  Pointlessly, truth be told, because no practicable DPF to date captures the nanoparticulates that are the actual biologically dangerous component of diesel exhaust.

I don't think there is a consequence to 'diesel exhaust fluid' use (other than some trivial pumping power) as it goes in entirely after the engine is done with the exhaust, and if anything slightly reduces any back pressure on the exhaust valves.  On the other hand, to the extent that catalytic operation permits hotter exhaust and higher compression ratio (as, for example, it should in locomotives using the C170 or QSK90) it's entirely possible that far more desirable combustion conditions can be used while still meeting very low political nitrogen-oxide emissions.  (Will the fuel savings and other efficiences make up for the handling and product costs for DPF?  Probably not directly ... but if DPF is mandated for other reasons, quite a bit of the other NOx-reduction technology or performance-degrading configuration can be removed or relieved, and that may involve very meaningful criteria.)

 

 

*Note that I want to reserve "steam" for hot water vapor that is to be used expansively for power generation, or by contact for reheat, in a Rankine cycle, rather than dilute the sense by using it in this context.

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Posted by Firelock76 on Saturday, September 23, 2017 8:19 PM

Wunderbar!  Er ist wieder da!

Welcome back Overmod!  Missed ya, buddy!

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Posted by Shadow the Cats owner on Sunday, September 24, 2017 4:51 PM

The current generation of DPF filters requirements are a full regeneration at every 40 hours the engine is run regardless if it is at idle or full throttle. For safety reasons the truck makers only allow regeneration to happen at speeds over 20 mph to prevent fires on the pavement catching fire and just from the sheer heat of the process. 

 

Now we still are running EGR on our engines and now also have the added maintenance required to maintain the SCR systems also. They are not 100 percent reliable. We have had injector failures tank heater failures and the funniest one for one of our drivers was the one that blew the pump apart and sprayed basically urine onto an 1800 degree filter housing.  He wasn't happy let alone the tech that had to replace everything. 

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Posted by Firelock76 on Sunday, September 24, 2017 5:43 PM

You know, calling that additive "urea" had me wondering if maybe, just maybe, it was fairly close to the other stuff I won't mention.

I just read the post to Lady Firestorm, who's having hysterics even as we speak!

I'm sure it wasn't a "whiz" for that poor mechanic to clean up either.

Sorry, couldn't resist.  Mea culpa, mea maxima culpa!

Hey, here's an idea!  Maybe the folks that make the urea additive should get together with JT's "Mega-Steam," the folks that manke smoke fluid for model trains.  They have all sorts of scents like "Cinnimon Bun,"  "Bacon and Eggs," "Granpa's Pipe Smoke," "Original Lionel Smoke Pellet," you get the picture.  Mix it with the urea and in case of a mishap everything will smell nice and not nasty.

I happen to use the "Coffee" scent.  It really does smell like coffee!

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Posted by Shadow the Cats owner on Sunday, September 24, 2017 7:29 PM

DEF was at first synthased from hog urine. Then they came up with a fake version of the needed nitrogen rich feedstock requirements to make it from.  The fake crap stinks worse than the real stuff.  The worst part is the stuff crystallizes and freezes faster than the real feedstock stuff. 

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Posted by tdmidget on Sunday, September 24, 2017 9:48 PM

Hmmm, I thought MY memory was bad, but not as bad as a few here. Let's set the record straight. Air injection into the exhaust gases was the first exhaust emission control, required in 1966 for domestic cars and 1968 for imports. Mileage dropped immediately with a Chevrolet 350 CID V8 getting 13 MPG on a good day and stayed there until Catalytic converters were introduced in 1975. The two were not used together.

Then we have Shadow's rampage on urea. It's not ignorance as I have corrected him before. Therefore it's stupidity or just a lie. Once again, urea is a colorless, odorless solid and is  not produced from hog farms or cattle and  is produced by the reformation of natural gas in oil refineries. I have personal knowledge of this, having worked on the equipment that does it.

Remember "Always at war with those that think OTR trucking is EASY." Time to  stop these rants.

 

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Posted by erikem on Sunday, September 24, 2017 10:53 PM

tdmidget

Hmmm, I thought MY memory was bad, but not as bad as a few here. Let's set the record straight. Air injection into the exhaust gases was the first exhaust emission control, required in 1966 for domestic cars and 1968 for imports.

Not quite...

California was requiring PCV on cars prior to 1966. Air injection was to cut down on the HC and CO, though I wonder how much of a problem is caused by CO in open air (confined spaces are a different story).

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Posted by tdmidget on Sunday, September 24, 2017 11:35 PM

erikem

 

 
tdmidget

Hmmm, I thought MY memory was bad, but not as bad as a few here. Let's set the record straight. Air injection into the exhaust gases was the first exhaust emission control, required in 1966 for domestic cars and 1968 for imports.

 

 

Not quite...

California was requiring PCV on cars prior to 1966. Air injection was to cut down on the HC and CO, though I wonder how much of a problem is caused by CO in open air (confined spaces are a different story).

 

PCV is a crankcase emission, not exhaust. It was , in fact, in place on most British cars already. It was relatively painless as if your crankcase emissions were that bad, you needed an overhaul anyway. As far as I know there were never any realistic complaints about PCV.

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Posted by Overmod on Monday, September 25, 2017 8:37 AM

tdmidget
As far as I know there were never any realistic complaints about PCV.

There were plenty! but usually involving what happened when the system either clogged or leaked.

One very good example involved BMW M73 twelve-cylinder engines.  In these, the PCV valves are built into the end-caps of the cast intake runners, and they have some kind of Viton diaphragm that was supposed to have long life, and probably would except not in a hot environment exposed to crankcase gases.  When, not if, the diaphragm failed, full manifold vacuum would pull not just vapor but actual oil from the valvetrain underneath the PCV port in the valve cover up into the intake runner... which slopes slightly backward as the engine sits in the car.  It was a crapshoot whether the dreaded lightning-bolt low-oil warning would come on before the ponded oil started to drool into the back cylinder(s).  And then you discovered that to replace these things, according to the BMW tech manual, involved pulling the engine up and forward to access the PCV valve's four Torx screws...

Is that enough of a complaint?  And it involves no blow-by issues into the crankcase, which was a primary reason for early PCV adoption (and likely the thing you mention as 'requiring overhaul')

  (As a peripheral issue, I have a car with the old 'road draft tube' system that was used for crankcase ventilation prior to PCV, complete with little wire-mesh catch bucket for the dribbles, and there were far more potential issues with water intrusion, nighttime condensation, etc. with the open tube than with vented return with proper regulating valve to the manifold.)

As a peripheral railroad note: there are documented cases of death from CO poisoning in early EMD locomotives operating in 'open air' -- the wind was unfortunately blowing with exactly the same speed and direction as the consist, with inversion holding the exhaust down.  Since CO poisoning is short-term irreversible binding to form methoxyhemoglobin, excessive standing CO concentrations in, say, LA traffic could easily cause quite a problem.

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Posted by Paul of Covington on Monday, September 25, 2017 9:46 AM

tdmidget
Hmmm, I thought MY memory was bad, but not as bad as a few here. Let's set the record straight. Air injection into the exhaust gases was the first exhaust emission control, required in 1966 for domestic cars and 1968 for imports.

   You may have been correct about your memory.   I owned '67, '69 and '74 vehicles, all without air pumps.   The '74 had Chrysler's "lean-burn" technology instead of air an pump which ran OK except that you had to warm it up about ten minutes before it would run.   Most other cars had the air pumps and catalytic converters by 1974.   As has been mentioned, you may be thinking about the PCV valve.

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Posted by erikem on Tuesday, September 26, 2017 11:59 AM

Overmod

As a peripheral railroad note: there are documented cases of death from CO poisoning in early EMD locomotives operating in 'open air' -- the wind was unfortunately blowing with exactly the same speed and direction as the consist, with inversion holding the exhaust down.  Since CO poisoning is short-term irreversible binding to form methoxyhemoglobin, excessive standing CO concentrations in, say, LA traffic could easily cause quite a problem.

 

I'd take it the tailwind and inversion was causing a fair amount of unintended EGR, leading to production of CO from the diesel engines. One big reason for using diesels vs gas (mixture) engines in submarines and mining was the much lower CO concentration in the exhaust of diesel engines.

My point about limits on CO in exhaust was directed more as whether any further reductions in CO are warranted as current limits seem to be adequate with respect to avoiding CO poisoning (people are having a harder time committing suicide with auto exhaust - unfortunately knew someone who used that for his suicide in 1975) and I haven't run across any reference to CO causing problems such as with NOx and HC. CO appears to be broken down by the soil.

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