Engines for Waste Oil use

[Crumpite]

I have a strong interest in running CHP units on waste oils or vegetable oils locally produced from crops.

Is anyone aware of research done on what types of Diesel engines are most suitable for waste oil use ?
I've heard of some practical work done in India, but nothing else.
I not aware of any fundamental research on the subject.

"common knowledge" says that IDI's are best, but some DI's seem to be in use also.
I'm not an engine mechanic or expert, so I'd like to see this considered as part of our research.

Thanks,
Crumpite

[cschuerm]

I, for one, don't know what aspects of a diesel design are important considerations for operation on non-diesel oils.  Maybe just starting with a known list would help identify engines that are more likely to be successful on waste oils.
Engine speed
IDI/DI
injection system pressure/design
compression ratio
combustion chamber design
cylinder/piston materials
??

Chris

[mobile_bob]

i would expect the most successful design would be an idi engine

and the pistons top ring would be of keystone design, and likely stainless steel allow

probably relatively high compression ratio would help, as would running at higher temperatures
like 205 or better degree F. which would require a pressurized system

bob g

[cschuerm]

Is there a difference in actual burn time/ dwell/ flame propagation in veggie vs diesel?  I've been really tempted to design a highly tunable electronic injection controller for the listeroid.  Would love to try out various combinations of injection timing as well as a multi-fire system like some of the modern diesels are doing to quiet them down.  I don't know what kind of flow range the modern automotive common rail systems have or even if it would be possible to tweak them down to listeroid ranges, but after trying to get the injectors to fire about about the same DBTDC on my twins, I bet I could at very least get the engine to run a lot smoother than those indian cam lobs could ever hope to.
Chris

[Crumpite]

i would expect the most successful design would be an idi engine

and the pistons top ring would be of keystone design, and likely stainless steel allow

probably relatively high compression ratio would help, as would running at higher temperatures
like 205 or better degree F. which would require a pressurized system

bob g

Ok, like I thought, IDI's are perhaps a better choice due to the swirl pattern burning.
I know that keystone rings are considered higher performance, but why stainless ?
Higher compression ratio equates to higher combustion temperatures and higher efficiency, but more pressure on the piston bearing surfaces, makes sense.

Does anyone how how to specify an existing engine thermostat for a certain temperature ?
Or will I have to install some complex control system to regulate the coolant flow and thus temperature ?

Good stuff so far...
Crumpite

[EBI-WPO]

The control of injection (electronically) would be easy on the common rail stuff. A crank trigger, some retrofitted ignition parts (think MSD or similar) or even some analog control would give serviceable timing adjustment for Electronic injection.
It is the hardware to support it that costs. A Cp3 pump and two electronic injectors in working condition would easily cost more than you paid for the Lister. Injectors are typically $400-600 a piece. And at that cost, few would want to gamble on other than clean #2 diesel.

Just my opinion,

Terry