Author Topic: Lister w/ DI and Nat Gas fuel  (Read 7258 times)

dkmc

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Lister w/ DI and Nat Gas fuel
« on: November 24, 2006, 03:58:28 AM »
Has anyone here experimented with using propane or Nat Gas as a primary fuel in a Listeroid?
I have seen it done with a VW Diesel in a lab. The Diesel injection is used to ignite the Nat Gas, but the engine runs mainly on Nat Gas, or somewhere upwards of 60% Gaseous fuel with 40% Diesel used for ignition and upper cylinder lubrication. 
Increased power with little or no additional noise, and some increased  temperature.

In my application, for the winter months, Natural Gas is most likely the lowest cost fuel I could use. (WVO is not free, and depending on what your time is worth, maybe not even cost effective).  My application would be to use Nat Gas to turn a generator before scavenging the heat for building heating. With no demand charges on Nat Gas (YET!) it makes sense to use the energy to turn a generator instead of sending it directly to a furnace.
I am in need of any information members might have regarding Gaseous fuel injection into a Listeroid engine.
The increased temperature might well be a plus for heat scavenging.

Any thoughts?   :-\

Dan K

dkwflight

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Re: Lister w/ DI and Nat Gas fuel
« Reply #1 on: November 24, 2006, 04:37:29 AM »
Hi In my opinion propane could be injected in a diesel through the inj pump, But!

1. a diesel injecter pump would leak. Probably. Probably would have to be a custom made item.
The nozzle would have to be designed to not leak under pressure untill the pressure rose enough to inject( higher than the saturated pressure of propane.)

2. Lubricant would have to be added continuously. I think it would settle out of the propane in the tank.

Much better to add the propane through a gas carb linked to the governor rack.

Dennis
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

dkmc

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Re: Lister w/ DI and Nat Gas fuel
« Reply #2 on: November 24, 2006, 04:42:48 AM »
' Much better to add the propane through a gas carb linked to the governor rack.'

Agreed. Mostly....
Running anything other than liquid fuel oil, WVO, etc thru the injection pump is not an option.
Will not work, and not required anyway.
There is little if any lubricant in propane, and nothing to settle out of it in the tank.
Nat Gas has NO lubricating qualities, and thats harder on any engine, which raises life expectancy questions.
How to get the gaseous fuel in the engine is not an issue.
How the engine (Listeroid) behaves on said fuel is the question.

dk
« Last Edit: November 24, 2006, 04:48:21 AM by dkmc »

dkwflight

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Re: Lister w/ DI and Nat Gas fuel
« Reply #3 on: November 24, 2006, 05:02:30 AM »
Hi
Natural gas and propane engines generally last much longer due to clean burn.
I thought the injecters would need lube. Thats why i suggested extra lube in the fuel.

Other posts in the recent past have suggested gas fumigation is viable.
Somebody has to try it.

One story I read about a pickup truck with manual propane control worked well. I think under a steady load manual control through a regulater should work fine.

Just do it
Dennis
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

biobill

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Re: Lister w/ DI and Nat Gas fuel
« Reply #4 on: November 24, 2006, 05:14:07 AM »
How would one govern such a thing? If the injector  is just acting as an igniter, wouldn't that turn it into a hit or miss engine if you relied on the stock governing system?

                                                        Bill
Off grid since 1990
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Needs diesel lawnmower & chainsaw

dkwflight

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Re: Lister w/ DI and Nat Gas fuel
« Reply #5 on: November 24, 2006, 11:21:33 AM »
Hi  As I understand the process, the rack is still governed by the speed Just like the load was reduced. The gas takes part of the load.
In a NA diesel you won't be able to add much gas before you get missfiring.
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

Jim Mc

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Re: Lister w/ DI and Nat Gas fuel
« Reply #6 on: November 24, 2006, 03:24:24 PM »
Why wouldn't you fix the rack position at a low level - just enough to keep the engine running at a very slow idle.  Then rig the governor lingage to somehow control the gas flow? 

dkmc

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Re: Lister w/ DI and Nat Gas fuel
« Reply #7 on: November 24, 2006, 03:59:06 PM »


I think thats a good idea Jim.
Perhaps a separate governor for the gas carb would be best.
I suppose modern electronics could be employed to govern engine speed also.
Then there is the question of actually adding a spark plug and ignition coil to
make the engine true spark ignition......dual fuel perhaps.
But I like the  DI approach the best.

Just wondering of any ill effects from increased heat and firing pressure on the Lister design, although the massive bearing area
and general robustness of the castings may make it a moot point. Valves and guides may suffer from the effects of Nat Gas the most.
I need an engine to experiment with!!

dk

Firebrick

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Re: Lister w/ DI and Nat Gas fuel
« Reply #8 on: November 25, 2006, 05:16:32 PM »
You dont want to use a carb, just a  nozzle with a regulator and valve to vary the amount that injects it into the intake stream.  The carb would limit the oxygen pulled in and therefore cause problems with the diesel burning(Ie to rich).  Natural gas and propane injected in this manner would not cause any problems with increased heat or pressure.  In a spark engine they limit the oxygen to burn it lean to decrease emmisions and that can cause problems.  In a diesel there is no problems with this as there is no restrictions in the intake stream.  All hydrocarbon fuels have close to the same energy "per pound"  and as a result there is no issues of gaseous fuels having increased heat or higher firing pressure than diesel fuel. 

With a regulator/valve setup you just increase the gas fuel when the engine is running at its lowest load.  As you increase the amount of  gas the diesel injection rack will start to close.  Increase the gas until the point that the engine starts to run rough and then back off the gas a little so it runs smooth.  Leave the gas at that point and the governor/injection pump will self adjust to increasing load. 

I would be afraid of locking the injection pump into one position and adusting the gas flow.  If the engine for some reason started to run away and you had to fumble with the injection pump lock to shut it down it might be too late.  If the injection pump is closed all the way even if the gas fuel is still flowing the engine will shut down as there is no form of ignition. 

cujet

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Re: Lister w/ DI and Nat Gas fuel
« Reply #9 on: November 25, 2006, 09:39:11 PM »
I believe there are some experimental airport shuttle buses with diesel/propane fueling. The diesel is just for ign and the propane is for the actual power produced. It results in a very clean diesel engine.

I think the above post is correct. The diesel inj pump remains at or around the idle setting. The propane is injected into the intake manifold in varying quantities to adjust power and rpm.

However, with nat gas furnaces around 80++% efficient, I think your best money is still to use nat gas as heat only. You will have to do some quality engineering to achieve that level of overall efficiency.

Honda builds or built a conbined cycle unit with 90% efficiency. It runs on nat gas, generates electrical power and makes heat. If they can do it on a production basis, you can do it on a one off basis.

Chris
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Geno

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Re: Lister w/ DI and Nat Gas fuel
« Reply #10 on: November 26, 2006, 12:33:06 AM »
This is all off the cuff, guesstimate, feels about right, experimentation. Do NOT try this at home.

I had all the parts, so just for the hell of it I rigged up a little propane tank to my engine yesterday. Maybe I'll refine it, maybe not, maybe I won't have a need to use it at all.
I adjust it by opening the valve a little bit to the point that if I remove the hose the engine reacts like I applied a 500 or so watt load. If I attach a fitting to the hose at that adjustment and light it I get a 4 or 5" yellow flame. The valve is barely open. Just like I've heard the rack closes as gas is increased.
After about 5 hours of running  (4.5 on WVO) my IDI chamber had less carbon than when I started and was for the most part carbon free. It had a very light layer of carbon that was more like soot when I started. If I go with this I'll just use a 1 lb. bottle every few hundred hours (to be adjusted as needed) to get rid of the carbon. I want to burn as much WVO as possible and I don't want to clean the head if I can avoid it. The engine sounds the same with the propane on or off.



http://www.genedevera.com/listeroid/#engineroom

Thanks, Geno

dkmc

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Re: Lister w/ DI and Nat Gas fuel
« Reply #11 on: November 26, 2006, 10:08:07 PM »
Well, it would be nice if I actually got email notification of responses on this thread, but most of these forum sites aren't very good about that.
Just checked back here and am amazed at these responses!

BIG big thanks to Geno for the experimentation and report !
Makes sense that the rack would close down with the added gaseous fuel.....and how handy that it 'regulates itself' in that way!
Geno, I wonder if there would be -any- sign of increased heating under full load conditions...? 

Firebrick is absolutely correct, no throttle plates allowed in the intake on a diesel.
I wonder if a venturi would help mix the gas for even distribution.......maybe at least a spray bar with a series of small holes to assure
even mixing of gas/air....??  I admit I like electronics for engine monitoring/ control, so the idea of an electronic governor and fuel 'injection'
system seems interesting to me.

Cujet: I think your best money is still to use nat gas as heat only. You will have to do some quality engineering to achieve that level of overall efficiency.

Here is the punchline to my proposal......

Here in Upstate New York, at my shop, 3 phase electric is very expensive.
When I divide my monthly electric charges by killowatt hours, it comes out to around .22-.24 cents -per- KWH....!
We are taxed to death on utilities, and the demand charges are a form of legal highway robbery...
Although my shop is small, and there are no demand charges if I am below 5KW, it always works out that the bill reads 5.2 or 5.3KW demand minimum. Go figure....
With electric rates in these ranges, I think it is well worth considering the generation of power on site, with waste heat as a 'free' by product....
The full payback on the project may only be 3 or 4 years.....?
If I'm mistaken, please tell me why.....
 
thanks for your info guys!

dan k

dkwflight

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Re: Lister w/ DI and Nat Gas fuel
« Reply #12 on: November 26, 2006, 10:27:49 PM »
Hi With 3ph charges the way they are I would certainly get 3ph gen head.
Just to run the shop equipment. A plus would be to run your house loads.
Dennis
28/2 powersolutions JKSon -20k gen head
Still in devlopment for 24/7 operation, 77 hours running time

Stan

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Re: Lister w/ DI and Nat Gas fuel
« Reply #13 on: November 26, 2006, 10:47:04 PM »
Water injection would increase power and clean the carbon deposits also.
Stan

mobile_bob

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Re: Lister w/ DI and Nat Gas fuel
« Reply #14 on: November 26, 2006, 11:29:20 PM »
water injection will clean the engine quite well, but won't increase power.

water injection usually can increase power in spark engines by allowing advanced timing

something to keep in mind is water vapor displaces oxygen which cuts power output in most cases, but not by much

i suppose it is like everything, a comprimise, you give up a touch of power to have a clean engine. not a bad trade off in my opinion for the vast
majority of folks

a diesel running in dual fuel mode (diesel pilot and gaseous primary fuel) will exhibit a reduction in power output, how much of a reduction depends on the ratio of gaseous to diesel and maintain a stable running engine (probably in the neighborhood of 75/25). the engine will not run hotter under load because of the decrease in the overall btu average of the two fuels being lower than that of running on straight diesel.

i know if i was you, i would be looking to find an ST 3 phase head, and would have it setup to power the shop for at least the 3 phase loads

bob g


otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info