What is the difference between a diesel engine and a gasoline engine?

3.Comparison of the structure of diesel engine and gasoline engine.

Gasoline engine electronic ignition diesel engine is compression ignition, diesel engine is strong power, noisy, suitable for heavy duty, gasoline engine bath sound is small and fast.

The diesel engine vibrates and makes a lot of noise, but it is fuel-efficient and climbs greatly, while the gasoline engine has low noise and small vibration, and the speed is fast but fuel-efficient.

In terms of fuel: diesel is ignited by compression, gasoline is ignited by spark plugs, and the deflagration value is different! Diesel is a low-speed output high-power engine, which is mostly used for large-scale pulling and carrying goods! The gasoline engine is a high-speed engine, which is generally used in cars! Environmental protection: diesel is more environmentally friendly than gasoline engines!

The diesel engine is powerful, and the gasoline engine is more environmentally friendly.

One relies on electric sparks**. A pressure**. The diesel engine is efficient, but noisy, and it does not use electricity for ignition.

The differences between gasoline engine and diesel engine are as follows:

1. The gas mixing method is different. The general gasoline engine enters the cylinder after mixing with air outside the cylinder, while the diesel engine injects diesel directly into the cylinder and mixes with the air.

2. The ignition method is different。Diesel engines require spark plugs to ignite the gas mixture, while diesel engines are ignited by compression and spontaneous ignition.

3. Power and torque are different. If you compare the gasoline engine and the diesel engine with the same displacement, you will find that the power of the gasoline engine is greater, but the torque of the diesel engine is greater. This is mainly due to the large compression ratio of the diesel engine and the large piston stroke, so it can emit more torque.

The biggest advantage of diesel engine is that it can emit more torque at lower speeds, and the power is sufficient. However, due to the low speed, the power is not large, and the maximum hour of a gasoline car is generally faster than that of a diesel car.

Differences: 1. Gasoline engines generally inject gasoline into the intake pipe and mix it with air to form a combustible mixture, and then enter the cylinder, which is ignited by a spark plug and burned to expand to do work. It is often referred to as a ignition engine.

The diesel engine generally injects diesel directly into the engine cylinder through the fuel injection pump and fuel injection nozzle, and evenly mixes it with the compressed air in the cylinder, spontaneously ignites at high temperature and high pressure, and pushes the piston to do work. This type of engine is often referred to as a compression-ignition engine.

2. The characteristics of the traditional diesel engine: good thermal efficiency and economy, the diesel engine adopts the method of compressed air to increase the air temperature, so that the air temperature exceeds the spontaneous ignition point of the diesel, and then sprays diesel, diesel spray and air mixture at the same time ignition and combustion. As a result, the diesel engine does not require an ignition system.

At the same time, the fuel supply system of diesel engines is also relatively simple, so the reliability of diesel engines is better than that of gasoline engines.

3. The advantages of diesel engine are high torque and good economic performance. Each working cycle of a diesel engine also goes through four strokes: air intake, compression, work and exhaust. However, because the fuel used in diesel engine is diesel, its viscosity is greater than that of gasoline, it is not easy to evaporate, and its autoignition temperature is lower than that of gasoline, so the formation and ignition of combustible mixture are different from gasoline engines.

4. Due to the high working pressure of the diesel engine, the relevant parts are required to have high structural strength and rigidity, so the diesel engine is relatively bulky and large; The manufacturing accuracy of the fuel injection pump and nozzle of the diesel engine is high, so the cost is high; In addition, the diesel engine works roughly, and the vibration and noise are large; Diesel fuel is not easy to evaporate, and it is difficult to start when the car is cold in winter. Due to the above characteristics, diesel engines were generally used in large and medium-sized trucks in the past.

1) The intake air is different: gasoline engine.

It is a mixture of gasoline and air, and diesel engine is air.

2) The ignition is different: the gasoline engine is the ignition type, and the diesel engine is the pressure type.

3) The mixture forming device is different: the gasoline engine is a carburetor.

Diesel engine combustion chamber.

What is the difference between a gasoline engine and a diesel engine? Both of them belong to the flame-resistant engine, the difference is that the raw materials used are different, one uses gasoline and the other uses diesel.

First of all, their first difference is:

The gasoline engine has a spark plug.

Diesel engines have a fuel injector.

The second difference is:

The gasoline engine is ignited.

The diesel engine is compression-ignition.

The characteristics are different: The compression ratio of a diesel engine is large, while that of a gasoline engine is small.

When the vast majority of car owners buy a car, whether they have strong power is one of the important criteria. The engine is the source of the power of the car, and it is also the heart of the car, which determines the performance of the car, and the engine can be said to be the most important part of the car. Engines are divided into internal combustion engines, external combustion engines, electric motors, etc., among which gasoline engines and diesel engines belong to internal combustion engines.

Precautions for diesel engines.

Pay attention to the oil pressure: when the diesel engine is working, the lubricating oil is pressed to the friction surface of the parts by the oil pump and forms an oil film, so that the parts that rub against each other do not have direct contact, so as to reduce the friction.

The level of oil pressure indicates the technical state of the lubrication system, and the oil pressure should be paid attention to at any time during use. When the oil pressure is too low, it should be stopped immediately for inspection and maintenance. Too high oil pressure will also damage the oil film and aggravate wear, and the cause should also be identified and eliminated in time.

Diesel engines are compression-ignition.

The gasoline engine is ignited.

First of all, in terms of combustion mode, gasoline engines are ignited by spark plugs, while diesel engines are compression-ignited without spark plugs. Secondly, in terms of emissions, the main emissions of gasoline engines are carbon monoxide, hydrocarbons and nitrogen oxides, while the main substances emitted by diesel engines are particulate matter and nitrogen oxides.

The gasoline engine, also known as the ignition engine, is an engine that injects gasoline into the intake pipe and mixes it with air to become a combustible mixture and then enters the cylinder, ignites and expands through spark plug ignition, and uses gasoline as fuel to convert internal energy into kinetic energy. The advantages of gasoline engine are that the gasoline engine has high speed, fast response, simple structure, easy to start in winter, light weight, low noise, low cost, stable operation, convenient use and maintenance, etc.

The diesel engine is also known as the Diesel engine, and the name ** is because the diesel engine belongs to the compression-ignition engine, and the inventor is RDiesel. A diesel engine is an engine that burns diesel fuel to obtain energy release.

The advantages of diesel fiber oil machine are high reliability, high torque, good thermal efficiency and high economic performance. (Photo by Wu Binbin, Pacific Destruction Auto Network).

The three major differences between diesel engine and gasoline engine are:

1.The difference between fuel and ignition method.

Diesel engines use diesel as fuel, and gasoline engines use gasoline as fuel.

Diesel engines are compression-ignition, that is, the high temperature generated by the compression of air in the cylinder is used to ignite the diesel. Diesel engines do not require spark plugs.

Gasoline engines are ignited, i.e., electric spark plugs are used to ignite a combustible mixture of gasoline and air.

2.The difference between compression ratio and efficiency.

The compression ratio is the ratio of the volume of the gas mixture in the cylinder at the end of the compression stroke to the volume at the end of the inlet stroke.

The compression ratio of a diesel engine is generally larger than that of a gasoline engine, because a diesel engine only compresses air, while a gasoline engine compresses the mixture. The compression ratio of diesel engine is generally between 14 and 22, while the compression ratio of gasoline engine is generally between 9.

The higher the compression ratio, the higher the combustion efficiency, so the thermal efficiency of diesel engines is generally higher than that of gasoline engines. The thermal efficiency of diesel engines can reach 35% to 45%, while the thermal efficiency of gasoline engines is generally between 30% and 40%.

3.The difference between power and torque.

Power refers to the work done by the engine per unit of time, and torque refers to the torque exerted by the engine on the crankshaft.

The speed of a gasoline engine is generally higher than that of a diesel engine, so the power of a gasoline engine is generally higher than that of a diesel engine. The speed of the gasoline engine for cars can be as high as 5000 6000 rpm, and the gasoline engine for trucks can reach about 4000 rpm; The maximum speed of diesel engine is generally about 2500 3000 rpm.

The compression ratio of the diesel engine is high and the piston stroke is large, so the torque of the diesel engine is generally higher than that of the gasoline engine. Torque reflects the engine's explosive power and ability to climb hills. The diesel engine can produce greater torque at lower speeds, which is suitable for vehicles with large loads, such as trucks, engineering vehicles, off-road vehicles, etc.; The gasoline engine is suitable for small vehicles with light loads, such as family cars, etc.

Fuel is ignited differently.

The gasoline engine relies on a spark plug to ignite the oil entering the cylinder, while the diesel engine relies on the high temperature generated by the compressed air of the piston to make the diesel burn on its own. Because the auto-ignition temperature of gasoline is higher, it is not realistic to achieve compression ignition of gasoline, and the gasoline can only be forcibly ignited by the high temperature generated by the spark plug. The auto-ignition temperature of diesel is relatively low, as long as the compression ratio is large enough, the temperature generated by the piston compressed air is enough for the diesel to ignite and burn on its own.

As a result, diesel compression ratios are generally larger so that sufficiently high temperatures can be generated at the end of the compression stroke. Because the higher the compression ratio, the higher the thermal efficiency, so the thermal efficiency of diesel engines is generally higher than that of gasoline engines.

The way it burns is different.

Whether it is diesel or gasoline, if you want to burn, you must let the oil evaporate into fuel vapor first, and then mix with air to form a combustible mixture.

Because gasoline evaporates very strongly, the gasoline engine is fully mixed with the air before the spark plug is ignited, for example, the common gasoline engine is injected in the intake stroke, so that the gasoline has enough time to evaporate and mix in the intake stroke and compression stroke to form a uniform combustible mixture. Towards the end of the compression stroke, the spark plug creates an electric arc that ignites the mixture, and the engine can do external work. Since gasoline is highly evaporative and has sufficient time to mix with air after entering the cylinder, the injection pressure of the gasoline engine does not need to be too high.

The diesel engine does not inject fuel in the intake stroke and compression stroke, and only at the end of the compression stroke, when the temperature in the cylinder rises sharply, the fuel injector will start to inject fuel. Due to the high viscosity of diesel, the injection pressure is very high, and the diesel is sprayed into very small mist-like droplets, which quickly evaporate and mix with air when exposed to high temperatures in the cylinder, and then burn themselves. Therefore, the diesel engine starts to inject fuel at the end of the compression stroke, and burns while spraying.

The gasoline engine indirectly controls the amount of fuel injected by controlling the amount of air intake, and there is a part called the throttle on the intake line, which is controlled by the accelerator pedal, and the throttle is like a valve that controls the amount of air entering the cylinder. The deeper the accelerator pedal is pressed, the greater the throttle opening, and the more air enters the engine. The engine control computer then calculates the amount of fuel injected according to the amount of air intake from the cylinder, so as to control the power output of the engine.

The diesel engine is much simpler, and the power is directly controlled by the amount of fuel injected. Diesel has no throttle valve, and the maximum air intake can always be obtained in the cylinder, and then the power is adjusted by controlling the amount of fuel injection. If you press the throttle lightly, the amount of fuel injected is less, and the power is small.

When the throttle is heavy, the amount of fuel injected will increase, and the power will be stronger.

When the gasoline engine is working, the throttle will have a certain obstruction effect on the intake air, so the resistance of the piston to suction will increase, which will consume more engine power. The diesel engine does not have a throttle valve, and the piston suction is always very easy, and it consumes less power, which is also a reason for the high thermal efficiency of the diesel engine. However, the current diesel engine also has a throttle valve, but that is mainly with the exhaust gas recirculation system to control emissions, which is very different from the throttle valve of gasoline engines in terms of use.