From the thermodynamic point of view, there are several ways to reduce exhaust emissions and improve combustion efficiency: increasing excess air coefficient, increasing compression ratio, increasing intake pipe pressure, optimizing injection and ignition timing, and reducing heat loss and friction loss.
Engine energy saving mainly includes the following technologies:
Lean burn technology, as its name implies, is to reduce the gasoline content in the engine mixture, and the oil-gas ratio reaches 1 to 25. At present, major companies have their own in-cylinder direct injection lean combustion technology, and Mitsubishi's mixture has reached 40+ 1? .
FSI stratified fuel injection is a lean combustion technology. Through the air movement in the cylinder, a rich mixture of 1 to 12 is formed around the spark plug, and the outer layer is 1 to 25, and the combustion is from the inside out.
High-energy ignition, in order to improve the ignition speed, some engines use double spark plugs or multi-stage spark plugs to increase the ignition energy and improve the flame propagation speed.
In-cylinder direct injection, at present, major companies have their own in-cylinder direct injection technology, Bosch Motronic? Med7 direct injection, Audi FSI direct injection, Mercedes-Benz CGI direct injection and Fiat JTS direct injection, with different names, are all in-cylinder direct injection of gasoline engines.
Variable valve timing can improve intake and exhaust efficiency by delaying closing and opening the intake port in advance.
By cutting off the oil in different cylinders and cutting off some cylinders under low working conditions, the fuel saving potential can be increased by 2 to 3 times and the emission can be reduced. Cadillac XT4 cylinder 2 cylinder, Ford fortes cylinder 1 cylinder.
Double supercharging technology, turbocharging and mechanical supercharging. Mechanical supercharging contributes to torque output at low speed, while turbocharging has higher power output at high speed. These two technologies are combined and give play to their respective advantages at the same time.
The core technology of variable compression ratio is to install a wedge slider between the cylinder block and the cylinder head. The cylinder block can move along the inclined plane of the slider, changing the relative position of the combustion chamber and the top surface of the piston, changing the volume of the combustion chamber, and thus changing the compression ratio. Nissan began to develop a variable compression ratio turbocharged engine on 1998. After 20 years, the first officially mass-produced variable compression ratio turbocharged engine was developed in 20 18. Different from the crank-connecting rod structure of the traditional engine, the original multi-connecting rod system realizes the intelligent stepless switching of the engine compression ratio from 8: 1 (high performance) to 14: 1 (high performance).
These technologies are common terms used by various original equipment manufacturers to promote their products. At present, there will be no big breakthrough in combustion technology, and increasing 10% is a major technological innovation. Pollution to the atmosphere and dependence on energy are still unresolved. Lao Liu said that with the gradual deterioration of the global climate, fuel vehicles have gradually changed from benefiting the people to endangering the people. Therefore, it is imperative to replace traditional energy with new energy, and new energy is not a problem in China.
This article comes from car home, the author of the car manufacturer, and does not represent car home's position.