Increased efficiency

[Doug]

I can only think of one way to increase efficiency and thats to slow the Lister down at lighter loads soits always running at the point where maximum fuel efficency meets demand.

I still think that a DI listeroid is a perfect match for the Imbert gassifier in dual fuel mode.
Does the time to prepare wood blocks and service the gassifier justify the fuel displaced and do you have a free source of hardwood at least 20 pounds a day?

 rough guesses
 Fuel oil $12.00 Mbtu ( more depending on tax )
 wood blocks $4.00 Mbtu ( depending on the level of processing )

 cylinder wear based on 1000h inspections
( Norstron with Volvo, test series done for the Swedish department of ecconomic defence 1957-1962 )

 fuel oil .015mm - .035mmm
 producer gas .007mm - .019mm

 labour:
 tough call how dirty are you willing to get your hands every day aprox 1 - 2h of daily service preperation and fueling from log to the ash bin.

I realy see no other reasonable way to co-gen unless you have free fuel from some other place.
That and realy the cleanest most efficient combustion from a diesel is going to be fuel oil pillot ignition of gas fuel. H2, C0, CH4, < 500ppm of heavier synthetic HC with a hi level of inert nitrogen results in very low emisions.

Doug

[mobile_bob]

i am left to wonder why you need to run 16 hrs per day with a battery bank?
not chiding you, just wondering?

for instance my plan:

1100 amp hr capacity battery bank.

running the batteries from 50 - 80% capacity or roughly 30% of the 1100 amp hours or 330 amp/hrs per day, this will
run all my projected needs for battery/inverter loads, ie. compact florescent lights, tv, intemittent microwave, refrigeration (small)

this would allow me to run the gen set one hour in the morning and one hour in the evening, to charge batteries from the 50-80% and...
drive an ST genhead to provide 60hz 120/240 for scheduled loads, washer, dryer, dishwasher and other heavier loads, albeit not all at once, some in the am run, some in the pm run.
the byproduct, waste heat can be recovered for domestic hot water production and space heat.

under this scheme the engine can be run near its rated load, up to rated temp, and at it maximum thermal and volumetric efficiency,,, thus get the most out of the fuel.

once a week i will run a much smaller unit as long as it takes to top off the batteries, and then once ever two weeks top off and equalize as needed.

unless you have a real need for 16 hours of continuous high power output, and can recover the waste heat, i don't see how you are going to get by much cheaper.  but if that is what you need then

look into alternative fuels, veggie, waste oil, blended or straight.....

look into (i will catch hell for this one) tuned intake and exhaust runners to improve the volumetric efficiency of the engine,
in a diesel this will help a bit, usually used to increase power because of getting more air into the engine thus the ability to burn more fuel. but in theory it might pick up a few percent,,,, i stress might!
getting a thermostat on the engine and keeping the engine up to around 190 degrees will make it more efficient, or certainly higher in efficiency than at 160 degrees

your biggest efficiencies are going to come from careful load management, battery charging, scheduling, and most of all
conservation.

far easier/cheaper  to conserve a kwatt of power, than to generate, store and deliver it

bob g

[dkwflight]

Hi  Nobody suggested the running temps of your engine.
My suggestion is to use a fairly small capacity cooling system and thermostats to get the engine up to operating temps quickly. A water to oil heat exchanger to get the lube oil hot and keep it hot while running. The oil should be at water jacket temp to boil off condensation in the oil. Hot oil will go through the oil filter better too.

From what I've been reading I would not go too light  on the oil. Straight 30 probably is best altho I am using 10-40 diesel oil. There was a thread recently about abnormal wear in the bearings possibly from light viscosity oil.
Good luck
Dennis
PS my engine has very few hours on it due to job hours.

[mobile_bob]

"Hi  Nobody suggested the running temps of your engine."

excuse me? 

your points on getting the oil temp up is are good ones, tho

i would also expect the life expectancy of these engines will increase as well at higher temperatures
they sure do with all other diesel engines

bob g

[Twinscrew]

Slowspeed is asking how to increase efficiency of his engine with regard to fuel consumption, otherwise known as Brake Specific Fuel Consumption (BSFC). So far everyone seems to be focusing on the secondary energy conversion (rotational to electric) while overlooking the primary conversion (fuel oil to rotational). Losses are compounded at each conversion. The greater the energy at the primary conversion, the greater the energy after the final conversion. So, how can he decrease BSFC ? By increasing the Volumetric Efficiency (VE) of his engine. The engine is an air pump that happens to enjoy it's own production of power. As in any pump there are losses called, quite appropriately, pumping losses. In order to avoid a lengthy dissertation as to why and how, suffice it to say that with regard to air; the easier in and the easier out the higher the VE. The higher the VE the lower the BSFC. As in just about every other internal combustion engine on the planet, some amount of improvement can be made by smoothing or even polishing the intake and exhaust ports. How much improvement depends on many parameters and variables. However, the valve seat to port transition in MOST engines is horrific. Flow at the valve is critical to this transition. Improvements of up to 20% VE are typical in an engine that has been ported and polished. A 20% improvement of VE can result in a like amount reduction in BSFC. That's a whole lot of beans and rice where Slowspeed comes from.

[GuyFawkes]

people are confusing many things.

volumetric efficiency is the ability of the engine to breathe, important if you're after high power, important if you are running a stoichiometric engine, eg petrol.

Lister is a diesel, provided you aren't getting black exhaust it is running very very lean, plenty of unburnt oxygen in the exhaust, so no benefit in getting more air in.

polishing a gas flowing ports will save you precisely the amount of energy lost to turbulence in the ports, eg bugger all proportionally speaking.

The OP doesn't run a Lister, but he is trying to make one run more economically, cart, horse, etc.

You would save more converting TRB mains to plains, but again first you have to own and run a lister.

[cujet]

Due to the slow speed of this engine, Guy thinks the VE is quite good. I will make an attempt at measuring it someday.

Certainly, there are a large number of factors involved in extracting maximum energy out of the fuel. A cast iron piston is a good start.

I think thermal coatings may assist in this also. Running the engine at a high temperature will help. As will things like modern low friction piston rings.

Here are some ideas if your are interested in changing the nature of the Listeroid.

1) Tuned airflow (intake and exhaust tuned runners) Low restriction filter and muffler.
2) Actual flow bench work on head
3) Increase compression ratio (probably your best gains here)
4) Reduce combustion heat losses. (important in slow speed engines)(theramal barrier coatings?)
5) Reduce piston ring drag (modern, thinnerm, TiN rings? fewer rings)
6) Reduce piston friction (DLC, diamond like carbon coatings) are a favorite now and seem to work well.
7) Camshaft tuning. There may be some advances in cam timing theory you could explore.
Valve train losses. Roller rockers have somewhat less friction. I'm considering this for other reasons.
9) Oil pump losses. Some here feel an oil pump is not necessary.
10) Oil windage. Some effort can be made to reduce oil splash to the minimum required.
11) RPM control. Lower RPM has lower frictional losses. Load dependent?
12) Reduce crankcase pressure. (the reed valve is not so good on most listeroids) Try a better reed valve.
13) Turbocharging (good turbosystems make more intake pressure than exhaust pressure, assisting efficiency)
14) Injector spray pattern and pressure. (higher pressures and better atomization result in more complete combustion)


Note: The Listeroid BSFC is very average. Some of the Changfa engines exceed and many modern diesels far exceed the Listeroid BSFC. The best numbers come from turbocharged diesels. I think there may not be much you can do within the limitations the Listeroid has. I truly think the better options would be to find a source of cheap fuel.

Like many others here, I was led to believe the Listeroids were efficient. That is truly not the case. They are not at all efficient by modern standards. The low consumption is simply a matter of low output.

For what it is worth, some modern air cooled GASOLINE fueled aircraft engines have equal or better BSFC numbers than the Listeroids. Better even than any modern automotive gasoline engines made today. The numbers are as follows. The best gasoline aircraft engines today regularly achieve 0.38 pounds fuel per HP/HR.

The Listeroids are 275 grams per KW/HR. That is more than 1/2 pound fuel per KW/HR produced at the flywheel! Or as compared to the aircraft engine example, 0.451 Lb/HP/HR. (Edited to correct stupid math mistake. I should have known the number was way off, even 2 strokes are not that bad, sorry)

Edit: 0.451 is about what current top shelf 4 stroke automotive gasoline engines achieve. Most gas engines today are about .5 pounds fuel per hour per HP. The best diesels are in the .31 range.

[rocket]

you got you numbers backwards... kw/gal is more than hp/gal ..  it is kw *.746/gal to compare

[GuyFawkes]

Like many others here, I was led to believe the Listeroids were efficient. That is truly not the case. They are not at all efficient by modern standards. The low consumption is simply a matter of low output.

Only because everyone keeps bullshitting about what BHP is, when all it is is a damn good indicator of rate of fuel consumption and rate of heat production in your given heat engine.

Torque, nothing else matters. Except perhaps low exhaust gas temps which do give an indication of efficiency.

Measuring electrical output of an alternator is not very far removed at all from a brake dyno, which measures BHP, which (TA_DAAAAA!) is another way of measuring fuel use rates....

Put a belt driven compressor or water pump on a lister, measure weight / volume of water lifted (and intake and outlet temps) and head and time, and compare that to fuel used in the same time period, and it will beat any other method and EVERY method using electricity, whether AC or DC, by margins you won't believe.

BHP is bullshit, so, by extension, so is watts.

[slowspeed1953]

Twinscrew,

Thanks for giving me some ideas to help add to my bean and rice stores

Chris,

Thanks for putting the efficiency of the lister's in perspective. Ive noted that a 6/1 is around 1500cc if it were an 8 cylinder engine it would be a 12 litre engine making 48 horsepower?

Best wishes

[mobile_bob]

"Thanks for putting the efficiency of the lister's in perspective. Ive noted that a 6/1 is around 1500cc if it were an 8 cylinder engine it would be a 12 litre engine making 48 horsepower?"

yes and that don't seem like much until you consider that is at 650 rpm!


the guys have given you alot to think about, but remember the following

it is always cheaper to conserve than to generate and/or store power.

when  you are considering efficiency as it relates to how much fuel per month you will be burning, it is very narrow sighted to only look at the listeroid to make the improvements

you should really be looking at overall system efficiency, and what it would take to improve each segment, and do a cost/benfit analysis. not just cost in money, but time, longevity and dependability of the whole system

my thinking is, i would bet i could design a system that using your parts, that would provide you with all the power you need, get everything done in the way of work, and do it with at least 1/3 less fuel per month, and perhaps 1/2 the fuel with some load scheduling

all without going to any trouble trying to increase the efficiency of the engine, which in my opinion will be quite difficult to get any real mearsureable increases in efficiency or show any less fuel burned per month. at least not anything substantial.

short of having a lab, and all sorts of instrumentation, and a very well thought out approach, raising the efficiency more than 3 or 4 % is going to be a very costly and time consuming task,, save in one area,,, that is the inclusion of a thermostat.

and lastly, after you have carefully considered the overall system efficiency, look seriously into co or trigeneration, the use of the waste heat to either heat with in the cooler months, or make domestic hot water, is something that if used can significantly raise the overall efficiency of your system. Trigeneration or refrigeration, can also be implimented and will also be something to consider.

the bottom line is you don't want to be just building another home depot type of genset, that you want to drag out in the back yard, crank up and run 24/7 , using the listeroid instead of a briggs and stratton. unless that is all you are after, if so then economics of operation really has no place in the discussion.

so think about it and let us know how you turn out

bob g

[xyzer]

four hours per gallon pedal to the metal, eleven or twelve hours to the gallon at lighter loads, small reductions in fuel consumption won't be noticeable, big ones impossible.

efficiency is where it's at, generate DC to charge DC accumulators.

Guy from your number of posts you must really now lister/listeroids really well.

I was just thinking if I was using a 6/1 as my only source of power it could be run as much as 16+/- hours per day that figures out (thanks for the data) to 120+/- gal/month of diesel, in my neck of the woods approaching $3.50/Gal thats $420+/- a month in fuel costs certainly not chump change (at least not to my pocket book.

Is there is no way to reduce fuel consumption at all? Just 10% less consumption would save $42/ month $504/year

Thats a whole lot of beans and rice where I come from.

Best wishes

Slowspeed....I can't help you much in the decimal points on efficinacy but in the bean area I like guys 1/2 WVO then add 1/2 RED Farm fuel.....If your $3.50/gal is farm fuel well...you are in the sticks!.....I'm not sure what the tax is in your area but here farm fuel is 10-15% less.....I think?! A big savings in the bean area. Then add some WVO, Oil from changes even. It won't help the consumption but it will take fewer beans to get almost the same output or whatever you want to call it. Work maybe?
Dave

[cujet]

You are right I got my numbers backwards. But I did not say anything about KwHr/Gal.

746 watts per HP.

So, if a Listeroid burns 275 grams of fuel per hour per KW/HR. It should be 275 times .746 which equals 205g/HP hour, Sorry for the confusion.

[slowspeed1953]

@.25gal/hr and 6 horsepower equals 44% thermal efficiency pretty fuckin good baseline.

Best wishes

[fattywagonman]

44% is excellent efficiency... I always thought the DI listeroid should be aleast 35% efficient..  complete combustion... low rpm.. high compression... and DI all  improve efficieny... IDI.. high RPM (because of pumping losses) and low compression (because of lower expansion) all reduce efficiency...  most DI engines with good combustion and a comp ratio in the 17 to 1 range are about 40% efficient. Cummins just announced a 45% efficiency for the ISB engine.. if the DI lister really is 44% then you're right there... Ellsbett also claimed a 44% efficiency with their oil cooled LHR design... so far the most efficient diesel is the big uniflow 2 strokes.. sulzer claims 56%.. GE recently broke the 60% barrier with a combined cycle gas / steam turbine... I'm  working on a 6 stroke combined diesel / rankine cycle engine that may prove to have an efficiency in the low 50's...