You might have heard of some diesel truck or pickup truck whose engine "ran" and only stopped once the diesel was gone. It truly is no exaggeration, no mechanic story (the gearhead edition of fisherman's story, you know ...). That type of thing transpires. The engine commences to accelerate all of a sudden and will not stop any longer. The moment a Detroit Diesel engine becoming turned on right after thirty years stopped.
Scary, is not it? It can be as if it had been a monster that awakens furiously from its rest, ready to destroy individuals that dared to bother him.
The gasoline engine makes use of a throttle controlled throttle valve to control the volume of air and hence the volume of fuel to control the engine speed. In diesel engines the principle is somewhat distinctive: there is no butterfly valve, as well as engine speed is controlled through the variation of fuel injected into the cylinders. The diesel engine accelerator acts on an injection pump that regulates the volume of diesel to be sent to the engine.
Diesel will not use spark plugs for combustion - its ignition is by injecting the fuel in to the compressed air and heating the cylinders. Therefore, when the diesel commences for being injected into the cylinders with no pressure or volume regulation, the engine can accelerate uncontrollably. This involuntary and uncontrolled acceleration is called "diesel runaway", often known as "engine fired" in Brazil. But how does this come about? In lots of other ways, as we shall see below. For much more details visit curso de mecanica
In the initial case, in far more worn engines, where there exists clearance in between the pistons as well as the cylinder walls, the combustion gases can pass via the sides of the pistons and in to the crankcase and carry oil mist in to the inlet. Because the lubricating oil has combustion properties much like that of diesel, the engine accelerates with this more fuel injection. The larger the engine speed, the better the volume of oil mist forced by means of the crankcase breather, creating an engine electrical power cycle that will lead to the total consumption with the lubricating oil and consequent breakage - normally an explosion like this:
This cyclic lubricating oil feed can also come about when you put too a great deal lubricating oil from the engine - that is why the manuals are emphatic: hardly ever include extra oil than advised. It is because rather than steam or mist of oil, who can climb via the breather would be the lubricating oil itself, which will cause the identical "firing" with the engine.
Probably the most frequent condition, nevertheless, is what we see in the video above: a failure or misadjustment with the injection pump or the accelerator. Within the video situation, the man was apparently adjusting the injection pump point when a thing went incorrect plus the fuel flow was no longer controlled through the aspect, feeding the engine as though the throttle was completely depressed. Expanding the engine velocity triggers the oil to begin to rise by means of the vents, keeping the engine operating as in other situations. For much more details take a look at curso de mecanica
When realizing that his Detroit Diesel fired, the guy requires a brave as hazardous perspective. He picks up a piece of rubber or tarp and tries to regulate the sole issue that is within attain: the intake of engine air, resulting in the machine to drown. While in the approach he could have lost his fingers, but the good news is he just broke the blades in the turbine.
If you're wanting to know why he didn't get to the cockpit and turned off the engine, which is why diesel engines, as we have stated before, have no spark to ignite. The engine is shut down from the fuel shut-off. As the component responsible for cutting the fuel had broken in his hand, the sole answer was to drown the engine. Even so the method is hazardous: the engine can practically explode based on the velocity and quantity of fuel, and also you don't have to make use of your imagination to learn what takes place when an engine filled with oil and scorching iron explodes.
Nowadays, with electronically managed diesel engines this really is more difficult to come by, primarily considering that modern engines have security programs for closing the intake, which causes engine drowning. This also demonstrates the importance of executing the right maintenance procedures and checking the problem with the elements in advance of trying to commission them.
For extra information check out http://comoacabarcomansiedade.com/did-you-know-that-a-diesel-engine-can-shoot-3/
Nenhum comentário:
Postar um comentário