Abstract
Abstract:
Thermal efficiency of a Diesel Engine could be increased by increasing the compression ratio. However the compression ratio can be incraesed only up to the point of onset of diesel knock.
In the CI engines, diesel knock greatly influenced by the ignition lag or delayperiod. By reducing the delay period the compression ratio could be increased without the knock taking place.
This diesel knock could be removed by reducing the delay period. When keep on inceasing the compression ratio in order to achieve a higher Thermal Efficiency, diesel knock occurs and at this perticular time, if warter will be injected to the systemuntil the knock disappears. Since, the diesel knock disappears by spraying the water it allows the compression ratio to increase furtherand improve the thermal efficiency susequently.
However, it will not possible to keep on increase the compression ratio by cotinuously sparying water. After a certain point water spraying will cease to be effective.