Wednesday, February 27, 2013

The Diesel Engines

The Diesel Engines
The diesel engine is a type of internal combustion engine, more specifically, a trigger compression engine, where fuel is ignited by the high temperature of the compressed gas and not by means of energy (such as spark plugs).

This machine was found in 1892 by Rudolf Diesel, who received a patent on February 23, 1893. Diesel wants a machine to be used with a wide variety of fuels including coal dust. Present them at the Exposition Universelle He (World's Fair) in 1900 using peanut oil (see biodiesel). Subsequently improved and perfected by Charles F. Kettering.

How diesel engines work

Diagram of a thermodynamic cycle diesel engine ideal. Diesel engine working order sequence of numbers 1-4 in a clockwise direction. In cycle diesel engines, combustion occurs in constant pressure and discharge occurs in a fixed volume. Energy produced per cycle is the area within the line cycle.

Diesel engines that are in the museum

When air is compressed its temperature will increase (as stated by Charles Law), a diesel engine uses these properties to the combustion process. The air sucked into the combustion chamber diesel engine and compressed by a piston which docked, much higher compression ratio than gasoline engines. Some time before the piston at top dead point position (TMA) or BTDC (Before Top Dead Center), diesel fuel is injected into the combustion chamber under high pressure through a nozzle that mixes with pressurized hot air. The results of this mixing ignite and burn quickly. Spraying of fuel into the combustion chamber when the piston started approaching (very close) TMA to avoid detonation. Spraying fuel directly into the combustion chamber above the piston is called direct injection (direct injection) while spraying fuel into a special room that is directly related to the main combustion chamber where the piston is called indirect injection (indirect injection).

This caused the gas explosion in a sealed combustion chamber expands rapidly, pushing the piston down and produces linear force. Connecting rod (connecting rod) to channel the movement into the crankshaft and the crankshaft was converted into a linear force power play. Power play at the end of the crankshaft axis used for various purposes.

To improve the ability of diesel engines, are generally added components:
  • turbocharger or supercharger to increase the volume of air entering the combustion chamber because the air entering the combustion chamber is driven by a turbine in the turbo / supercharger.
  • Intercooler to cool air will enter the combustion chamber. Volume of hot air will expand and vice versa, then the cooled air that aims to occupy the combustion chamber can be more.
The diesel engine is hard to live on when the engine in cold conditions. Some engines use a little thing called electronic heater plugs light up (spark / glow plug) in the cylinder to heat the combustion chamber prior to ignition. Others use the heater "resistive grid" in the "intake manifold" to warm the incoming air until the engine reaches operating temperature. Once the engine is operating combustion of fuel in the cylinder to effectively heat the engine.

In very cold weather, diesel fuel thickens and increases the viscosity and forms wax crystals or a gel. This can affect the fuel system from the tank to the nozzle, making ignition engine in cold weather becomes difficult. How common is used to heat the fuel filter and fuel lines electronically.

For the application of an electric generator, an important component of the diesel engine is the governor, which controls the supply of fuel that the engine is always at the desired rotation. If the engine speed drops too much power quality issued will decrease so electrical equipment can not work properly, whereas if the engine speed is too high, it can lead to over-voltage that could damage electrical equipment. Modern diesel engines use advanced electronic control to achieve this goal through an electronic control module (ECM) or electronic control unit (ECU) - which is the "computer" in the machine. ECM / ECU receives engine speed signals through sensors and uses search algorithms and calibration tables stored in the ECM / ECU, he controls the amount of fuel and time through an electronic or hydraulic actuators to adjust the engine speed.

Type of diesel engine

Usually the number of cylinders in multiples of two, although any number of cylinders can be used for the crankshaft can be balanced to prevent excessive vibration. Inline 6 engines most widely produced in the medium-duty engines to heavy-duty, though the V8 and 4 line are also widely produced.

The diesel engine works with compressed air high enough so that the big diesel engines have added some more air. Then used a supercharger or turbocharger on the intake manifold, with the aim of meeting the needs of compressed air.


The advantages and disadvantages compared with spark-ignition engines

For the same power output, size of the larger diesel engines than gasoline engines because the construction is needed in order to withstand the high pressure combustion or ignition. With the construction of the huge fan is relatively easy and inexpensive modifications to increase power with the addition of a turbocharger without much thought to the resilience of the components of high takanan. Gasoline engines need a more accurate calculation for the modified power increase because in general the components in them is not able to withstand the high pressure, and makes diesel engines machine candidate for low cost modifications.

The addition of a turbocharger or supercharger to the engine aim to increase the amount of air entering the combustion chamber during compression so will result in a high pressure and at the time of ignition or combustion will generate great power. The addition of a turbocharger or supercharger on a diesel engine does not significantly affect the use of fuel because the fuel is injected directly into the combustion chamber during the combustion chamber in a state of highest compression ignition to occur to trigger the burning process. While the addition of a turbocharger or supercharger to the engine greatly affects gasoline fuel consumption because of air and fuel is mixed with the right composition before entering the combustion chamber, both for gasoline engines with carburetors or injection systems system.

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