COMPRESSED AIR ENGINE IN TODAYS LIFE

<font color=#000066>COMPRESSED AIR ENGINE</font>

Basically, when referred to ambient conditions, the relatively low energy content of the compressed air in a tank of acceptable volume is claimed to be insufficient to move even small cars over meaningful distances .On the other hand, another air car developer claims to have driven 184 km on one 300 Liter filled with air at initially 300 bar pressure. Obviously, there are issues to be resolved, not by heated debates, but by an analysis of the thermodynamic processes involved. In the relavant information isothermal conditions, this energy could be entirely converted to mechanical work. However, under isentropic conditions not more than 25 MJ become useful. By multi-stage expansion with inter-stage heating the expansion process is brought closer to the isothermal ideal. The analysis is extended to the compression of air. Again, the ideal isothermal compression is approached by multi-stage processes with inter-cooling. Based on this criteria energy demand for compression is reduced to acceptable levels and system pressure and temperature are kept within safe limits. The results of this analysis seem to indicate that the efficiency of the four-stage expansion process is acceptable, while even a four-stage air compression with inter-cooling is associated with significant losses. However, the overall energy utilization could be increased if the waste heat generated during the air compression process would be used for domestic water and space heating.