About the pressure of turbocharging

Turbocharging does not work in all working conditions. This is mainly because the effect of turbocharging on the engine is not obvious in the low speed range, but it increases the exhaust back pressure and the work required for exhaust.

Once the engine speed is too high and the boost pressure is too high, the engine heat load will be too high and the turbocharger will overspeed. Therefore, it is necessary to adjust the boost pressure of the engine. Adjusting the turbocharger can improve the matching between the engine and the turbocharger and improve the torque characteristics.

Development history:

/kloc-at the end of 0/9 century, with the birth of turbomachinery, people realized that it was different from piston internal combustion engine. 1905165438+10 In October, Alfred Butch, a Swiss engineer, put forward a scheme of combining piston internal combustion engine with turbomachinery, that is, exhaust gas turbocharger. 1925, bush obtained the patent of "pulse supercharging", which is still being studied as an important means to improve the performance of internal combustion engines in the 20th century.

In the 1920s, a Swiss company first designed and manufactured the first exhaust gas turbocharger, which matched the four-stroke diesel engine. This supercharger has a pressure increase ratio of 1.3 and adopts two-stage centrifugal compressor, which is another milestone in the development history of diesel engine.

1926, the world's first supercharger company was established in Switzerland. In the same year, Germany produced the first batch of turbocharged diesel engines, which increased the power of diesel engines from 423 kW to 55 1 kW, an increase of 30%. However, its pressure increase ratio is less than 15, and its service life is relatively short.

In the 1940s, turbocharger technology gradually matured, such as BF and E series with low pressure ratio produced by an American company, L and H series produced by 1949, C series produced in 1960s, VTR series developed by a Swiss company, MS and HP series developed by a British company, etc.

The representative turbocharger in this period was 1962, HS-400 turbocharger exhibited by a French company in Hanover. Turbocharger pressure ratio is 25, turbine intake (maximum temperature is 600, maximum speed is 20000r/min, weight of turbocharger 145 kg. Used in diesel engines of 294.2 ~ 441.3kw.