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Is a diesel engine's maximum rpm limited by the diesel burn rate?
Wiki User
∙ 13y ago
Burning techniques are totally different when comparing Diesel and Gasoline. In Gasoline engines, air and fuel mixture is injected into the cylinder (in a non direct fuel injection system) this mixture is then compressed and thus temperature of the mixture increases, but not to the ignition temperature, this is why we need a spark plug in gasoline engines to start this small fire. After reaching the top dead level of the cylinder (or sometimes even before that ) spark plug releases its charge and start a very small explosion inside the cylinder head. This small fire ball propagates as far as there is enough fuel and oxygen. While this explosion propagates, the piston is being pushed down and turning the flywheel through the crankshaft. As you can see, you don't need to compress this air and fuel mixture till ignition temperature and you don't want to do it!!! This is why it is possible to design gasoline engines with short strokes. Short strokes means short reciprocating movements, which means faster rotational speed.
In diesel engines, there is no spark plug, because ( and I'm not 100% sure about that ) Diesel is not a good fuel in propagating a controlled fireball. It just doesn't work very well in diesel. Because of that, Only air is being compressed inside a diesel engine during the compression cycle. Somewhere during compression stage, diesel is being injected inside the cylinder and starts to spread homogenously inside the cylinder, compression continues and the mixture is mixed and heated up till it reaches ignition temperature. Once ignition temperature is reached, the whole mixture explodes at the same moment. As you can see, there is no flame propagation in diesel engines, the whole mixture just explodes in a single moment. And in order to reach ignition temperature you need a long enough stroke to be able to compress air till it reaches ignition temperature of the fuel. Longer stroke means slower cycle, but higher torque. This is why Diesel engines have more torque but less speed than their gasoline counterparts.
Hope this answers your question.
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Okay...
The Diesel engine (named after Rudolf Diesel, who invented it) was designed to burn any flammable liquid you put in it--Herr Diesel originally intended to run it on vegetable oil. OTOH, a spark ignition engine requires fuel with a minimum amount of volatility, so gasoline has to be a very highly refined product.
The Diesel cycle compresses air inside the cylinder until it's hot enough to ignite the fuel. At that point, the injection system squirts a premeasured dose of fuel into a combustion chamber in the cylinder head. It ignites instantly. Because the flame front is confined to the little chamber the fuel's being injected into, there has to be a LOT of excess air in there. To get it, the engine is "oversquare"--the stroke is longer than the bore. (A Detroit Diesel DD15 is 5.47" bore, 6.43" stroke. It's an inline 6 engine that displaces 14.7 liters.
Now here's where it gets fun: The DD15 comes in eight different horsepower ratings, and the only difference between the eight engines is the fuel injector system--the more power your engine has, the more fuel the injector holds. (There's also a different program in the computer, but that's another issue.) Before the EPA got all antsy about diesel emissions you could take your truck to Pittsburgh Power, have them install higher-flow injectors and have a much more powerful truck for relatively little money. (You can't do that now; the current electronic fuel injection systems on big rigs keep you from doing that.)
Wiki User
∙ 13y ago
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Why petrol csnnot be used in diese engine?
The diesel engine is designed to use diesel, which reaches combustion at high (relatively to petrol) pressure and temperature. If petrol is injected into a diesel engine, then combustion will take place in a, very different than it was designed, way, which will eventually destroy the engine. But there are engines that have been designed to burn diesel or petrol. They call them bifuel engines. Old farmer tractors used to have this kind of engines.
Why petrol engines are faster than diesel engines?
Petrol engines are widely considered to be the most efficient of engines, because they are more refined than diesel. Since diesel is not completely refined, it cannot completely combust and so does not (in theory) produce as much energy per litre of fuel as a petrol engine. However, some diesel engines can be made to be much more efficient than petrol engines because they have a different type of fuel, and burn it in a different way. Petrol engines are widely considered to be the most efficient of engines, because they are more refined than diesel. Since diesel is not completely refined, it cannot completely combust and so does not (in theory) produce as much energy per litre of fuel as a petrol engine. However, some diesel engines can be made to be much more efficient than petrol engines because they have a different type of fuel, and burn it in a different way.
How much fuel does a large diesel cargo ship burn at cruising speed with a full load of container and what would that cruising speed be?
The Wartsila-Sulzer RTA96-C turbocharged 14 cylinder two-stroke diesel engine is the most powerful and most efficient prime-mover in the world today. The Aioi Works of Japan's Diesel United, Ltd built the first engines. At maximum economy the engine exceeds 50% thermal efficiency. Even at its most efficient power setting, the big 14 consumes 1,660 gallons of heavy fuel oil per hour.
How do petrol and diesel engines work?
No. Diesel and petrol, while both petrochemicals, act quite differently. Petrol is ignited by a spark, and at a relatively low pressure. Diesel 'self ignites' when placed under sufficient pressure, therefore diesel engines do not use spark plugs, and require higher operating pressures to work. To allow for the different pressures, there are large differences between the designs of petrol and diesel engines, carburettors/fuel injectors and valve systems. The only way to convert a petrol car to a diesel (or vice versa) is a complete engine swap.
Can you make a diesel engine which works on the basic principle of petrol engine or you can say it uses diesel as a fuel but works on the principle of petrol engine?
No, a diesel is a compression firing engine and a petrol is a spark firing engine. Diesel fuel will not burn in a petrol engine with spark plugs.
Can we convert public buses from diesel engines to LPG engines?
No, a diesel engine will not burn LPG. It would destroy a diesel engine. A gasoline engine can, with some modifications, burn LPG.
How much air is required to burn 1 liter of diesel in diesel engines?
9 cubicmetre ofair
Why otto cycle used for petrol engine and diesel cycle for diesel engine?
A standard 20 to 1 otto cycle is used for the petrol and diesel cycles for diesel engines. It is higher than gasoline engines due to the way diesels burn and compress fuel.
What is the advantage of Diesel engines?
One of the main advantage of using a Diesel engine as opposed to a regular is that a Diesel engine tends to burn less fuel. They also have very high thermal efficiency.
Do Diesel truck engines get better mpg than gasoline truck engines?
Diesel engines get better fuel economy because they do not need to burn as much fuel as a gas engine to get the same power. By design a supercharged engine will produce more power whether it be gasoline or diesel. A diesel engine has more torque at lower rpm than gas engines and therefore uses less fuel. The correct answer is YES.
Why petrol csnnot be used in diese engine?
The diesel engine is designed to use diesel, which reaches combustion at high (relatively to petrol) pressure and temperature. If petrol is injected into a diesel engine, then combustion will take place in a, very different than it was designed, way, which will eventually destroy the engine. But there are engines that have been designed to burn diesel or petrol. They call them bifuel engines. Old farmer tractors used to have this kind of engines.
Why don't buses use gasoline?
Buses, like many large vehicles, burn diesel fuel. Deisel-burning engines are better suited for large vehicles than gasoline-burning engines.
Why diesel engines called constant volume engines?
They aren't.Gasoline engines are (sort-of) constant volume engines while Diesel engines are (sort of) constant pressure engines.In a gas engine, the combustion process is so fast compared to the travel rate of the piston that it all happens in the same volume, before the piston has had much time to move away.In a Diesel engine combustion is so much slower that the piston will actually have time to move away while fuel is still being burnt.As the volume of the combustion chamber increases during burn as the piston moves away, the pressure will remain pretty much the same throughout the burn.
Can you put petrol in with diesel?
Most internal combustion engines are designed to burn petrol (gasoline) or diesel fuel, but not both. Unless the engine manufacturer tells you otherwise, you should not mix the two types of fuel.
Why petrol engines are faster than diesel engines?
Petrol engines are widely considered to be the most efficient of engines, because they are more refined than diesel. Since diesel is not completely refined, it cannot completely combust and so does not (in theory) produce as much energy per litre of fuel as a petrol engine. However, some diesel engines can be made to be much more efficient than petrol engines because they have a different type of fuel, and burn it in a different way. Petrol engines are widely considered to be the most efficient of engines, because they are more refined than diesel. Since diesel is not completely refined, it cannot completely combust and so does not (in theory) produce as much energy per litre of fuel as a petrol engine. However, some diesel engines can be made to be much more efficient than petrol engines because they have a different type of fuel, and burn it in a different way.
Who would use a steam engine?
Someone who doesn't want to burn gasoline. A steam engine has the ability to use anything that will burn. Had the technology been applied to steam engines like it was to gasoline engines, we possibly would have some viable steam engine transportation today. Steam engines were less efficient than gasoline or diesel engines, that is why they are not used much today.
Why do marine diesel engines burn base oil?
The larger a diesel engine cylider is, the cruder the fuel can be and still work. Also, the larger the cylinder, the more efficient the engine. "Base" or bunker oil is a lot cheaper than refined highway diesel.
