Everyone knows，Many models are allocated now are direct -injected gasoline engines in the cylinder。Some people will ask:Gasoline engine can spray gasoline directly in the cylinder，Why can't you directly burn it like a diesel engine? Why use a spark plug to ignite?

seabet app

This must first introduce a physical chemical term- "flash point"。flash point，It is under the specified test conditions，The minimum temperature that uses a certain ignition source to cause liquid vaporization and fire。

The flashing point of gasoline can be less than 28 ° C，and light diesel flash point at 45-120 ℃，Oil products below 61 ° C in flash point are flammable products。

It is difficult to ignite it when it is close to the diesel，Because the temperature is 20 ° C is far lower than the flash point of diesel，At this time, diesel is still very stable，No volatile，So it is difficult to ignite。

Diesel is not as easy to volatilize as gas as gasoline，Only the surface is on the surface of the air，and gasoline is easy to volatilize to produce more hybrids that are sufficiently generated by gasoline steam and air，This is seabet mylike the difference between wood and wood shavings。

The spontaneous combustion point refers to the temperature of the independent combustion of combustion the combustion in the conditions of oxygen，Diesel's self -burning point is only 220 ℃，That is to say, just mix with the air，You can burn yourself at 220 ° C。

The spontaneous combustion point of the gasoline is 427 ℃，The high temperature generated by the piston compressed air can reach the spontaneous combustion point of diesel but cannot reach the spontaneous combustion point of gasoline，So the diesel engine can use the pressure method，and gasoline engine can only be lit by spark plugs。

Spark plugs are introduced in the gasoline engine ignition system to introduce the high -voltage current into the cylinder to produce electric sparks，，Mainly from the wiring nut、Insulation、Wiring screw、Central electrode、side electrode and shell composition，Side electrode welding on the shell。

Spark plugs are arc discharge，No bright fire will be produced，So it can only ignite the gaseous combustion material mixed with oxygen，The gasoline we usually see is finally evaporated and vaporized in the cylinder，Only in this way can it form sufficient gaseous combustible mixture。

But the density of the diesel itself is large，and more stable in nature than gasoline，This kind of fuel is difficult to volatilize after being sprayed into the cylinder，Most of them are small diesel particles，It cannot form enough flammable and combustible mixture，So the spark plug cannot ignite diesel。

There is great differences in the combustion characteristics

gasoline engine is the use of "seabet appprefabricated mixed gas" fuel，That is to say, the mixture that needs to be burned during the work of doing work is already ready，Just wait for the time to ignite the spark plug to ignite it。

Because the time of ignition, basically happened near the Pistons arrive near the above stop point，At this time, the Pistons will have a directional action，Therefore, you can see that the burning space at this time is a short time，Mixed gas quickly completes the combustion and expansion at this moment，This is the Orto cycle of "fixed heating"。

and the diesel engine is to start in the cylinder when the piston is close to its spontaneous combustion point when the piston is close to its spontaneous combustion point.，Moistor mix with the air after entering the cylinder after entering the cylinder，Because the temperature reaches the spontaneous combustion point，Diesel starts burning，Due to the slow burning speed of diesel，So diesel that needs to be burned at a time will not spray instantly，Instead, it will continue to spray in the cylinder，As a result, it is continuous fuel injection while burning in the cylinder，The sprayed oil continues to mix with the air and be burned，The swelling air continues to promote the piston，This is the Disciel cycle of fixed pressure heating，Diesel engine in English is called Disiel Engine。

Someone asked: Why can't the compression ratio of the gasoline engine be higher，Also like a diesel engine at the compression, spray fuel in compression? This is mainly because the burning speed of gasoline is too fast，The combustion process is uncontrollable，It is difficult to make the engine smoothly、soft。

The physical characteristics of oil products determine that they are "distinguished"。(The content of the article seabet mycomes from the Internet，If you involve the copyright, please contact delete)