Does this help?:
The Self Ignition Temperature of Diesel is 210°C and that of Petrol varies from 247°C to 280°C.
Carbon monoxide
Autoignition temperature 609 °C (1,128 °F; 882 K)
the autoignition temperature of hydrogen is 585°C
8 Likes
Pete; Good to know. Thank you TomC
2 Likes
Hi, Tom!
21.2.2020
Now, after Pete’s table I hope you can see the difference between a one-point controlled ignition and an allover detonation.
With spark or fuel injection (in a diesel) you have a controlled flame-front spreading out from ONE POINT to the periphery of the combustion chamber.
If a fuel distribution happens in a diesel allover the cylinder before the compression temperature for ignition is reached, then you will have destructive detonations.
That’s the same as (glowing)soot preignition in a gasoline motor = DETONATION!
Max
5 Likes
TomC,
Controlled IC engine combustion is a traveling flame front from one point ACROSS. This builds up a pressure rise pulse “timed” to the increasing volume of the moving down piston, and the more favorable rod/crank angle.
Just letting the fuel/air mix spontaneously random combust depending on the variable walls temp, the current air temp, engine loading temp WILL cause multiple points of combustion. The wave front from these will collide spiking huge pressures. And these explosive pressure wave will be at bad piston/rod/crank angles.
And this is why every single mainline engine manufacturer supping their engine to any use gasious fuels rips off the diesel injector and retrofits with an industrial spark ignition.
Finite controllablity.
Smart DYI wood gasers do this too.
Johan Leddel on his diesel three cylinder David Brown tractor. Converted to a six cylinder Volvo car IG distributor pinned every other terminal pin.
After years of fighting diesel pilot ignited engine problems the India CGPL folks went to supplied spark converter engines.
Remember. The Swedish experiment were for emergency no-oil make-work retrofitting.
Spelled F.E.M.A. as temperay use.
In real condition WWII Sweden they ran out of actual diesel by the 2, 3 year.
The India folks finally conceded that spark plugs, wires, ect would be much cheaper than having to supply pilot diesel fuel.
The currnet best-use LPG, methane, and hydrogen IC engine no longer use intake blending/mixing.
They controlled variable time/volume inject these fuels.
Gets rid of the detonation problems. Gives wider range of use flexibly.
S.U.
3 Likes
What is HCCI?
An HCCI engine is a mix of both conventional spark-ignition and diesel compression ignition technology. The blending of these two designs offers diesel-like high efficiency without the difficult—and expensive—to deal with NOx and particulate matter emissions. In its most basic form, it simply means that fuel (gasoline or E85) is homogeneously (thoroughly and completely) mixed with air in the combustion chamber (very similar to a regular spark-ignited gasoline engine), but with a very high proportion of air to fuel (lean mixture). As the engine’s piston reaches its highest point (top dead center) on the compression stroke, the air/fuel mixture auto-ignites (spontaneously and completely combusts with no spark plug assist) from compression heat, much like a diesel engine.
3 Likes
How is ignition timing accomplished? This comes out of crazytown.
Rindert
P.S. I can point you to a whole bunch of crazies if that’s what interests you.
Hi,Tom!
22.2.2020
You could aswell describe the “antique” glow-tube igniter!
Used often in agricultural mashines!
MaX
3 Likes
Right, or maybe a glow plug as used with 1970s model aircraft.
Rindert
2 Likes
High, Rindert!
22.2.2020
Yes, I flied them.
Max
2 Likes
Me too. For a long time.
2 Likes
I must be crazy. I don’t know why I feel I have to correct people when they make statements I don’t agree with. I will try one more time to make my point.
First Rindert; This is an engine manufactured by Mazda and used in automobiles. I feel they fell on their face with the rotary engine, so I don’t know if this will be a world beater—but it is not a theory or pipe dream.
Now to my point. I am saying that an atomized fuel will self ignite when put into the cylinder of an engine and compresses by the movement of the piston. One example I presented was at an injector rebuild plant, they screw an injector into a container with a glass window and pump fuel through the injector to watch the spray pattern. No combustion occurs. Then they put that injector into a diesel engine and crank the engine over, the diesel fuel will combust if sprayed at the proper time. The heat of combustion and the pressure cause a diesel engine to fire.
You are correct that the injector has to spray the fuel at just the right moment, the same as the spark has to occur at just the right moment to get best performance out of an engine.
In a gasoline engine you can have the same situation, if you have low octane gas, high compression, and late spark timing. Because the timing is not in play, this is not good for a gasoline engine. TomC
2 Likes
Too bad I bought me a Lister 30 hp engine and then found out that sparkignition is needed. Is that really or can the engine idle and run on woodgas?
1 Like
I have never worked with a diesel on woodgas but Mr. Wayne has. Hope he chimes in. TomC
2 Likes
Ha! Ha!
Well me too TomC.
I have ponder much how/why many will fixate on just the H,C&O’s of the fuel combustion process in isolation to the mechanism and CONDITIONS it is put to actually making work happen.
Damn. A nail is just a nail until you put it to actually working. MANY different kinds and types of nails for different conditions. Cost as one of the first considerations.
Dr Mukunda chose and insisted on the research laboratory as being names Combustion Gasification and Propulsion for the important reasons as these are all essentially the same.
It is the Application-To-Use that is the greater difference than the “fuel” or the other factors.
Yeah, yeah. Vaporizing of s-o-m-e fuel mixing in to the intake air stream works. Obviously.
WITH conditions use limitations!
Want the working machine to actually do work from sub-zero to the highest possible desert sun conditions? Safely. Reliably. The early 20th century Arctic and Antarctic explorers found only spec grades gasoline could do this with then know mechanical systems.
From below sea level to wheeled and tracked usage up to 15,000 feet? Tough, tough with gasoline mechanical/carburated systems. Until you go with actual gasoline fuel injection. Diesel as fuel injected - piece of cake.
Prior to the extreme dictated needs of minimizing exhaust emissions the four stroked connecting rod crankshaft engines won out over all other comers for use with mechanical mixed into the intake spray-able, valpor-izable and gasious fuels in all mobile/portable uses where fuel economy (as it should be) was a factor.
Yeah, yeah. Pumpable heavy oils fuels and add in the big 2-strokes too.
Only engine power uses restricted to “the best using” conditions like those model airplanes, and even the old vaporization agricultural engines can be stupid simple. And stupid simple will be virtually unusable in the really, really cold. Travel too altitude swings, etc.
My gasoline-mix Stihl power euipment and the modern out board engines are amazing as able to do these wide of use ranges too. Far, far from stupid simple. 100+ years in continuous developments refinements. Motor cycles the same.
Fellows on all of this; work backwards.
The NEED to be satisfied.
The actual available’s to you to possibly get this done. Internet interest links runs nothing.
HCCI; hydrogen engine fuels; non-crankshaft engines; all of this can be done if you are able to throw enough thousands of development hours and literally millions of dollars equivalents at it.
Sometimes the big corporation solutions will go mainstream.
Some of the current Mazda engines in production vehicles mixing Miller-cycling with HCCI. The Honda’s and Toyota’s select use of electronically variable camshaft/valve timing&lift Atkinson’s Cycle emulated degrees lengthen four stroke power cycles.
And sometime even the big corporation will pursue&promote will-NOT-satisfy world around all use needs “solutions”. VooVoo sexy just around the corner some-day’s actually sells their current products. No sales Today means no Tomorrow for them to be there. Bankruptcy.
The Wankel’s can/could never match piston engine fuel economy, durability and lowest emissions. GM finally realized this in 1974/75. Pivot shifted their development dollars into the exhuast catalysts. Not just the tech. The patent locks. The rare metals mines.
Gas-turbines? Fuel use economy. Cost of manufacturing and high skill maintenance needed.
Ha! Pick your own know failures to launch examples.
The easiest idea filter? Accept that Idealism’s are Enthusiasms. And these DO NOT make things go around and around with working purposes for the everyday persons practical uses.
JoepK,
I went out and bought a Lister clone 12/1 diesel injected engine to “Ideally” woodgas with. My biggest woodgas mistake. Lost half selling it to an engine collector.
Yes big, old slow, fewest cylinders diesel engines can be made to woodgas start, idle and low constant load run.
Poor. Poor. Modern day Choice. Many better engine choices will give much better work-use flexibly.
Woodgas in an IC engine works easiest operated at 1200-2800 Loaded RPM in my experiences. And since gasious mixed into the intake before the intake valve - engines with an all-use controllable spark ignition.
Now the gasifier to make the woodgas works best being sucked by at least a three cylinder IC engine. Better with four cylinders or more. For the steady intake suction.
Today. And yesterday, were the first times I was training the now 5 yo and 6 yo girls in peddle/ride standard bicycles.
You really wanna’ “hurts” understand crankshaft angles and how to variable apply the pushing power for best go-fast on a crankshaft system? Use a bicycle.
Grunt pushing on the peddles before a rolling crossover the top point angle HURTS! Ha! Coaster hub brakes stops the motions and Grunt/stand/push, leg hurts even more.
Grunt all you want. The power delivery timing just has to be right.
Ha! Once the balance-safe training wheels come off THEN can I advance them to better power delivery.
After just makes-go, come stopping. Then steering/turning. Then balance. ALL control points.
Better power comes last. Everything else has to be workable/right first.
S.U.
6 Likes
Thanks Mr Steve. Mine is a 30 hp, 2200 rpm 2 cyl with direct injection . Did you try running that cs? Anyway, here is 1000 gallons of veggie that definite has to make room. That alone is enough for two years, so I have time to find me another engine.
And indeed it is like learn riding a bike and no one likes to fall. But you have to or you can’t learn.
2 Likes
That 2 cycle worryes me. Obviously the woodgas needs to be super clean and dry.
1 Like
KristijanL his engine is a four stoke two cylinder inline.
JoepK, after over-the-shoulder looking at two different CS 6/1’s being woodgased; no I never did woodgas my larger 12/1. Pointless. Fight the more severe engine hopping. Fight the voltage/frequency flickering electrical generating single phase 60 cycles at these 600-1000 rpm’s. Just too many winds to be spitting against.
Sold it as I said.
Worked a bunch of different small four stoke single cylinder aircooled engines woodgased. Finicky.
A couple of aircooled V-twins. 999cc and 672?cc. Good results.
A few inline watercooled Kutota 3 cylinder factory converted propane engines. Flywheel triggered spark ignition. Easy, pleasie. Just $$$$.
And various old large generator powering 4 and 6 cylinder spark ignition watercooled. Easy to woodgas. Hard to frequency/voltage stabilize under loads-on and loads-off with the old worn mechanical governors. Needed fast response $$$ electronic governor/controllers retofitted as a start. Engines rebuilt to restore compressions. Full gasious fuel made up intake manifolds. Etc.
My personal use electrical gneration I now go with variable speed Honda&Yamaha engine driven inverter generators. Super easy. Let the factory electronics do ALL of the engine controling work.
S.U.
4 Likes
can I buy pellet power an engine ?
2 Likes
Thanks Mr Steve. I will give it a go anyways, the engine is here. But now I know already in which corner my bike will fall. Thanks.
2 Likes
Oh sorry, l read 2 ciycle. Quite a few old 2 stroke diesels were used here decades ago.
3 Likes