Here's how a diesel engine works
The diesel engine uses the working principle of the law of Charles, that is, when the air is compressed then the temperature will increase. Air is sucked into the combustion chamber of the diesel engine and compressed by a piston which is docked with a compression ratio between 15: 1 and 22: 1 resulting in a pressure of 40 bar (4.0 MPa; 580 psi), compared with a gasoline engine that only 8 to 14 bar ( 0.80 to 1:40 MPa; 120 to 200 psi).This high pressure will raise the air temperature up to 550 ° C (1,022 ° F). Some time before the piston enters the compression process, diesel fuel is injected directly into the combustion chamber under high pressure through a nozzle and injector that mixes with high-pressure hot air. Ensure that the fuel injectors are split into small granules and spread evenly.
Fuel vapor and then remains high due to the compressed air in the combustion chamber. These early fuel evaporation causes a timeout while the lighting, the sound of detonation appears in diesel engines is when steam reaches the temperature of the flame and cause a rise in pressure above the piston abruptly.
Therefore, spraying fuel into the combustion chamber when the piston approaches began (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 space that relates directly to the main combustion chamber in which the piston is called indirect injection (indirect injection).
This covered explosion causes the gas in the combustion chamber quickly expands, pushing the piston down and produce a linear force. The connecting rod (connecting rod) to channel this movement to the crankshaft and the crankshaft linear power was converted into rotary energy.
The high compression causes the combustion can occur without being required to separate ignition system (gasoline engines use spark plugs), so that a high compression ratio increases engine efficiency. Elevating the compression ratio in gasoline engines is limited to prevent damage to the pre-ignition.
The original engine Diesel inject fuel with the help of compressed air, which mengatomisasi fuel and forcing fuel into the combustion chamber through the nozzle (using the same principles as aerosol sprays). Nozzle openings closed by valves controlled by the camshaft to initiate fuel injection before top dead point / top dead center. Using 3 compressor stage is laborious, but the efficiency and clean power output generated above other combustion engine at that time.
Menggunakaan diesel engine is currently very high pressure with mechanical pumps and presses fuel injector without compressed air. With diesel direct injection, fuel injector will spray through a small orifice at noselnya 4-12. Early-generation injection diesel engine always has the initial burning without a drastic increase in pressure when burning. Currently research is being conducted to use again some form of air injection Rudolf Diesel's original design to reduce nitrogen oxide pollution. In all diesel engines, modern diesel engines always refer to the original design of Rudolf Diesel, in which fuel is lit by high compression.
For the application of an electric generator, an important component of the diesel engine is the governor, which controls the fuel supply so that the engine rotation is always at the desired rotation. If the engine turns down too much power quality issued will decrease the electrical equipment can not work properly, while if the engine rev too high, it can lead to over voltage that can damage electrical equipment. Modern diesel engines use advanced electronic controls to achieve this goal through an electronic control module (ECM) or electronic control unit (ECU) - which is a "computer" in the machine. ECM / ECU receives the engine speed signal through sensors and algorithms and search for calibration tables stored in the ECM / ECU, he controls the amount of fuel and time through the electronic or hydraulic actuators to adjust the engine speed.
Most diesel engine now has a turbocharger and some are a combination of turbo and supercharger. Because fuel in a diesel engine is not in the cylinder before combustion starts, then the air pressure of 1 bar (100 kPa) can be inserted into the cylinder without pre-combustion. Turbocharged engine can produce power much larger than ordinary machines with the same configuration, as more air is incorporated means more fuel can be burned so that a greater power. General mechanical supercharger driven by the engine crankshaft, while the exhaust gas turbocharger is driven by the engine, does not require any mechanical power. Turbochargers can reduce fuel consumption in diesel engines by taking waste heat from the exhaust gases.
Because the engine with a turbocharger and a supercharger to produce more power with the same capacity, then more attention should be considered in the design of mechanical components, lubrication and cooling. Piston generally cooled with lubricating oil which is sprayed on the bottom of the piston. Large machines that can use water, sea water or oil through a pipe attached to the crosshead teleskopi.
To improve the ability of the diesel engine, are generally added intercooler to cool the air will enter the combustion chamber. Hot air volume will inflate and vice versa, then the cooled air that aims to occupy the combustion chamber can be more.
There are two classes of diesel engines, two-stroke and four-stroke.
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 engine most produced in the medium-duty engines to heavy-duty, although the V8 and 4 line also produced.
The diesel engine works with compressed air which is quite high, so in large diesel engines need to add some more air. Then used a supercharger or turbocharger in the intake manifold, with the aim of meeting the needs of compressed air.
Source: https://id.wikipedia.org/wiki/Motor_bakar_diesel