Re: GAS-L: Internal Combustion with Producer Gas

[Peter Singfield <snkm@btl.net>]

High Tom R.

Diesels do much better at stop and go jobs -- ergo "city" buses running
diesels are much more economic than gasoline engines. (and then there is
retrofitting those with flywheel devices!!)

But if both engines are running at constant optimal conditions -- the
difference decreases dramatically. The diesel will still come out more
efficient though -- due to the higher compression ratio.

Pumping losses are theoretically nil -- just like pushing and releasing a
spring. Though in real time -- there must be a small mechanical loss -- I
would not lose any sleep over it!

On the other hand -- if you take the pedal off the metal on a diesel -- it
certainly slows down a lot faster than if you threw it into neutral.

And then there is the Jacob's Brake -- which is a diesel engine compression
device to save on friction braking -- your brake pads live longer.

So I guess intake and exhaust restrictions are responsible?? Valve timing??
Water cooling the jackets??

But certainly -- a reciprocating compressing and releasing uses no energy
beyond small mechanical losses. Oh -- make that an "insulated" cylinder!

Tricky question Tom --

I was just looking over some huge diesels -- they get 46% over all
efficiencies now!! Incredible!! (that burning crude oil!!)

Peter

At 10:20 AM 5/5/00 EDT, you wrote:
>Dear Peter, Prof. Parikh et al:
>
>My head is spinning from all this interesting discussion of diesel options.  
>I don't set myself up as a diesel expert, just a learning observer, so I bow 
>to Prof. Parikh's overall expertise and Peter's practical experience (GMC 
>"Jimmys" indeed).
>
>I commented on the "throttle losses " of the spark engine favoring diesel 
>efficiency over spark.  Now I wonder about "pumping losses" of all that
extra 
>air at part load being pushed out the diesel exhaust.  Does that favor spark 
>ignition?  
>
>Just asking....
>
>TOM REED
>
>In a message dated 5/3/00 7:23:38 AM Pacific Daylight Time, snkm@btl.net 
>writes:
>
><< 
> Agreed Tom -- but for "practical" applications where standard diesel motors
> will actually be used for running diesel/producer gas -- would this not be
> around 16 to 18:1?? 
> 
> Now -- here is another question -- of great importance!
> 
> What about two stroke diesels! They normally use pressurized (like in turbo
> or super charging) air to scavenge the cylinder. It has always been my
> impression -- having operated many GMC diesels -- that a great surplus of
> that air is blown out the exhaust.
> 
> This is not going to be good for producer gas enriched air intake systems
> -- efficiencies will drop with all the producer gas going through and not
> being combusted.
> 
> Comments?? 
> 
> I have one such application at hand now. Am thinking I can probably burn
> the exhaust to produce further heat.
> 
> This is OK -- as it is a rice producing facility and they need the heat for
> drying.
> 
> But they are running GMC diesels for power generation -- and the expense to
> change those motors kills the deal.
> 
> Geez -- I hope I am not getting to far ahead of this list again!!! Like in
> nobody being able to grasp the compression thingy. So important -- yet so
> "ignored"!!
> 
> Now Tom -- seems to me you are in the business of selling gasifiers for
> applications just as I am presently involved in. 
> 
> I was hoping for a broader understanding of the principles involved. 
> 
> In this application -- they would like to go 100% producer gas. But again
> -- tearing down diesels to alter compression ratios kills the deal.
> 
> Can you understand any of this?? We are talking real projects in real time
> now --
> 
> And yes -- can you gasify rice husks to do this??
> 
> They are presently spending $10,000 US per month for diesel fuel.
> 
> I have a number of such prospects. Here in Belize alone!
> 
> Now if this gasifier business works -- I need answers -- not stone walling!
> 
> It also has to be just as reliable -- and save money -- not cost more.
> 
> Ergo -- my sudden interest in the producer gas to engine subject!
> 
> Your "pining" away on the wrong details is not constructive at all. I know
> all about "smoke-screening". That simply hides facts that show the device
> in a bad light -- and does not lead to any solutions of the problems.
> 
> Which I believe have been very clearly stated.
> 
> We are not dealing with 25:1 -- or 14:1 but with standard diesel power
> plant diesel engines! and we can't tell the customer to change them for
> something "special" in order for the gasifier to work! Not in this "real"
> world -- where there is not funding or subsidizing. If it don't work the
> buyer goes broke!
> 
> My job is to make sure it works!
> 
> Peter
>  >>
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