The analysis of farm tractor diesel purification method

Diesel oil and gas mixed is uneven, and fuel cannot burn completely, resulting in decomposition to carbon based particles. At the same time, compared with the gasoline engine, excess air coefficient of diesel engine is very high, producing local high temperature and combustion, resulting in nitrogen oxide (NOx) formation, but the carbon monoxide (CO) and hydrocarbons (HC) emissions than gasoline engine is much lower, fuel economy is also very good. Thus it can be seen, the emission performance optimization of diesel engine of farm tractor machine, mainly to solve the problem of how to reduce nitrogen oxides (NOx) and particle.
Diesel combustion temperature of tractor reaches its maximum at the slow burning period, directly affect the nitrogen oxide (NOx) production. At the same time, slow burning period, if the engine is fuel, and the spray to the high temperature exhaust gas zone, or the mixture too thick, will lead to the lack of generated particle.
Therefore, in the angle of cleaning machine, you can moderate the relationship between maximum temperature and fuel concentration, reduce nitrogen oxide (NOx) generation. The booster multi valve technology, cooling technology, control of the injection rate and the exhaust gas recirculation. Adjusting the injection or the airflow organization, to make fuel burn quickly and completely, reducing particle generation. The exhaust gas turbocharger technology, improve the injection pressure, improve combustion chamber structure, reduce oil consumption, the use of low sulfur fuel, control of the injection process and regulates the fuel.

The exhaust gas turbocharger technology
According to the pressure in different ways, diesel engines of tractor China can be divided into: mechanical pressurization, pressure wave supercharger turbocharger, turbo, composite. The exhaust gas turbocharger is to use the engine emissions have some energy into the turbine and expansion work, drive the compressor and turbine rotating coaxial full power for the gas turbine, the compressor will send fresh air compression cylinder.
But the exhaust turbocharger technology also has some defects. First of all, low speed when the performance is not good. When the diesel engine at low speed, the power generated by the turbine will be reduced, resulting in the boost pressure compressor is reduced accordingly, booster effect is not good. Secondly, accelerate the slow response. Due to the use of gas engine driven supercharger, at least through a cycle exhaust volume will increase, will be reflected to the turbocharger, therefore the transient response is not good. Once again, the inlet, exhaust pressure sensitive. When the cylinder exhaust volume is too small, the supercharger will surge. When the cylinder exhaust volume is too large, the supercharger blockage can occur. The two non normal conditions will affect the boost pressure and work efficiency of turbocharger.