Abbreviations

3. Higher injection pressure of the air increases bmep as well as increases the value of SAC. The engine at full load shows a decrease of bmep and an increase of SAC with growing of

4. The mean temperature of working medium should be at above 300 K for proper lubrication of the two-stroke pneumatic engine. Because of such requirement, the injection

5. The presented hybrid vehicle with the combustion and pneumatic engine enables to achieve higher mean effective power and torque in comparison to the standard engine. The described hybrid engine can work in four modes (Section 6.1) depending on required

6. In the pneumatic working mode, the CI engine does not emit any toxic chemical species (zero emission) mostly in urban drive, which causes also a lower heat exchange with a

7. During the pneumatic working mode, the CI engine demands the air volume equal above 6 l under pressure 350 bar for the driving with constant velocity of 50 km/h in the city with a distance 10 km. For higher driving distance, the foreseen tank volume amounts not more than 30 l. Applying an additional high pressure air injection above 350 bar, one increases the theoretically total efficiency of the engine from 4 to 19% at micro-dose of air depending on the duration of air injection. The engine operating in the air microdose mode of the air can indicate the total efficiency higher than 50%. The engine working at full dose of air (combustion and pneumatic mode) indicates much higher total efficiency

8. Additional air in CI engines decreases CO, HC and NOx emission, which is caused by additional oxygen and lowering of temperature in the cylinder. In the compression ignition engine, a lower soot emission is expected, which is caused by penetration of fuel jet core by the injected air. The hybrid vehicle with combustion and pneumatic engine enables to reach zero emission of exhaust gases with high engine performance, despite it requires an additional power for compressor drive, which is recovered during vehicle

In this chapter, we presented only chosen aspects of clean pneumatic and hybrid combustion and pneumatic piston engines for application in transportation based on the own works. The presented experimental and theoretical works of other researchers indicate the needs of alter-

Future works should be concentrated on optimization of the air injection parameters in order to obtain a maximal efficiency. This can be performed also by simulations, but the control parameters should be verified on the experimental stand with real engine. Without the

rotational speed at the same injection pressure.

156 Improvement Trends for Internal Combustion Engines

power and reduction of exhaust gas emission.

cooling system (higher thermal efficiency).

reaching value 60%.

deceleration.

10. Future work

native and more ecological driving sources.

pressure of air should be above 50 bar (see Figure 4).

