Simultaneous reductions in diesel NO_x and smoke emissions with aqueous metal-salt solutions directly injected into the combustion chamber

摘要

The effect of several aqueous metal-salt solutions on NO_x and smoke lowering in an IDI diesel engine were examined. The solutions were directly injected into a divided chamber independent of the fuel injection. The results showed that significant lowering in NO_x and smoke over a wide operation range could be achieved simultaneously with alkali metal solutions which were injected just prior to the fuel injection. With sodium-salt solutions, for instance, NO_x decreased by more than 60% and smoke decreased 50% below conventional operation. The sodium-salt solution reduced dry soot significantly, while total particulate matter increased with increases in the water soluble fractions.