Difference between diesel engine and gasoline engine
2016-12-21 10:41:08
Due to the bad weather in winter, Russia's commercial vehicles are mostly used gasoline engine, in contrast, in order to achieve great load, China's commercial vehicle is the majority of diesel engines. Then the diesel engine and gasoline engine in the end what is the difference? What if the gasoline is added to the diesel engine? On the contrary what will happen? Today we give you popular science about.
● The combustion method is different
Different from the gasoline engine, the ignition mode of the diesel engine is "compression ignition", so there is no spark plug. To understand the difference between gasoline and diesel engines, we must first know the difference between gasoline and diesel. The molecular weight of gasoline is relatively small, easy to volatile; diesel molecular weight, volatile much better than gasoline.
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In the combustion of the engine, the more volatile gasoline and air can be more efficient mixing, and then by the spark plugs issued by a throwing spark can make the mixture produce a smooth combustion, and thus promote the piston.
Diesel volatile bad, can not be mixed with the air smoothly, it can not be ignited with a spark plug. But when the atomization of diesel encounter high temperature and pressure of the air, they will ignite the "flame of love", which is the so-called "compression ignition."
This means that the gasoline engine (non-cylinder direct injection) inhalation, compression is pre-mixed fuel and air, and diesel inhalation, compression is only the air, only in the combustion stage fuel mixed with air, so the diesel engine is not spark plug , Diesel engine fuel injection nozzle instead of the spark plug "position."
● More fuel-efficient diesel engine?
Because inhalation, compression of the air, the diesel engine does not need to worry about the compression stroke of the knock problem, the stroke of the piston can be designed to achieve a high compression ratio. The higher the compression ratio, the higher the stroke efficiency, so the diesel is more fuel efficient.
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But the gasoline engine (non-cylinder direct injection) to die, inhalation, compression is the mixture, if the piston stroke is too long, the compression ratio is too high engine knock problems will occur, so the gasoline engine does not have high compression ratio of the diesel engine.
But also because the high-pressure pump and injector to spray diesel at high pressure, so the lubrication of diesel is very important, otherwise the high-pressure pump and the nozzle will be worn. The sulfur content of the five diesel to reduce many, but also lead to reduced fuel lubricity, which will accelerate the aging nozzle.
● high torque is not high
Gasoline and air mixture in the combustion cylinder is very smooth, very good energy transfer. Diesel combustion is an uncontrollable process, the combustion may occur in the power stroke of any stage, so the diesel engine vibration and noise than the gasoline engine.
Because the diesel engine needs to be more robust design, so its own quality will increase, piston, connecting rod, crankshaft and other components will become more bulky.
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The greater the mass, the greater the inertial force, plus the piston stroke of the diesel engine is longer, if the speed is high, the engine will bear great inertia, which may lead to engine damage. Therefore, compared to the speed of diesel engines to be lower than the gasoline engine.
Power is a function of speed and torque, because the speed is not high limit the output power of diesel engines, so the diesel engine "horsepower (power)" is not.
But the diesel engine piston stroke is long, and diesel engines are often "booster + direct injection" configuration, combustion efficiency is higher, so the diesel engine torque.
If the diesel engine is added to the engine, the engine can not start, because the diesel can not be mixed with the air, the spark plug can not ignite the mixture.
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Conversely, the addition of gasoline to the diesel engine, is equivalent to a high volatile fuel sprayed into the high compression ratio, high temperature combustion chamber, which will lead to serious engine knock, thereby damaging the engine.
● Editor:
Because the diesel engine with great torque, so more suitable for heavy truck with the same truck in the transport process for the speed requirements are not large, because the piston engine piston design can be very long, compared to the gasoline engine More fuel-efficient, all the advantages and the needs of the truck coincide, so the domestic heavy-duty trucks are basically with a diesel engine.
● The combustion method is different
Different from the gasoline engine, the ignition mode of the diesel engine is "compression ignition", so there is no spark plug. To understand the difference between gasoline and diesel engines, we must first know the difference between gasoline and diesel. The molecular weight of gasoline is relatively small, easy to volatile; diesel molecular weight, volatile much better than gasoline.
20160724094620832083.jpg
In the combustion of the engine, the more volatile gasoline and air can be more efficient mixing, and then by the spark plugs issued by a throwing spark can make the mixture produce a smooth combustion, and thus promote the piston.
Diesel volatile bad, can not be mixed with the air smoothly, it can not be ignited with a spark plug. But when the atomization of diesel encounter high temperature and pressure of the air, they will ignite the "flame of love", which is the so-called "compression ignition."
This means that the gasoline engine (non-cylinder direct injection) inhalation, compression is pre-mixed fuel and air, and diesel inhalation, compression is only the air, only in the combustion stage fuel mixed with air, so the diesel engine is not spark plug , Diesel engine fuel injection nozzle instead of the spark plug "position."
● More fuel-efficient diesel engine?
Because inhalation, compression of the air, the diesel engine does not need to worry about the compression stroke of the knock problem, the stroke of the piston can be designed to achieve a high compression ratio. The higher the compression ratio, the higher the stroke efficiency, so the diesel is more fuel efficient.
20160724094646144614.jpg
But the gasoline engine (non-cylinder direct injection) to die, inhalation, compression is the mixture, if the piston stroke is too long, the compression ratio is too high engine knock problems will occur, so the gasoline engine does not have high compression ratio of the diesel engine.
But also because the high-pressure pump and injector to spray diesel at high pressure, so the lubrication of diesel is very important, otherwise the high-pressure pump and the nozzle will be worn. The sulfur content of the five diesel to reduce many, but also lead to reduced fuel lubricity, which will accelerate the aging nozzle.
● high torque is not high
Gasoline and air mixture in the combustion cylinder is very smooth, very good energy transfer. Diesel combustion is an uncontrollable process, the combustion may occur in the power stroke of any stage, so the diesel engine vibration and noise than the gasoline engine.
Because the diesel engine needs to be more robust design, so its own quality will increase, piston, connecting rod, crankshaft and other components will become more bulky.
20160724094796479647.jpg
The greater the mass, the greater the inertial force, plus the piston stroke of the diesel engine is longer, if the speed is high, the engine will bear great inertia, which may lead to engine damage. Therefore, compared to the speed of diesel engines to be lower than the gasoline engine.
Power is a function of speed and torque, because the speed is not high limit the output power of diesel engines, so the diesel engine "horsepower (power)" is not.
But the diesel engine piston stroke is long, and diesel engines are often "booster + direct injection" configuration, combustion efficiency is higher, so the diesel engine torque.
If the diesel engine is added to the engine, the engine can not start, because the diesel can not be mixed with the air, the spark plug can not ignite the mixture.
201607240947005252.jpg
Conversely, the addition of gasoline to the diesel engine, is equivalent to a high volatile fuel sprayed into the high compression ratio, high temperature combustion chamber, which will lead to serious engine knock, thereby damaging the engine.
● Editor:
Because the diesel engine with great torque, so more suitable for heavy truck with the same truck in the transport process for the speed requirements are not large, because the piston engine piston design can be very long, compared to the gasoline engine More fuel-efficient, all the advantages and the needs of the truck coincide, so the domestic heavy-duty trucks are basically with a diesel engine.