SIGNIFICANCE OF INLET AIR TEMPERATURE ON REDUCING ENGINE-OUT EMISSIONS OF DI DIESEL ENGINE OPERATING UNDER THE INFLUENCE OF OXYGEN ENRICHED HYDROGEN GAS

Increase in air pollution due to automotives is an important problem worldwide. Present
experimental work concerns with the influence of inlet air temperature along with oxygen enriched
hydrogen gas on reduction of exhaust emission and increasing the fuel economy of a DI diesel
engine. Here, the oxygen enriched hydrogen gas was produced by the process of water electrolysis.
When the potential difference is applied across the anode and the cathode electrodes of the
electrolyzer, water is transmuted into oxygen enriched hydrogen gas. The produced gas was
aspirated into the combustion process of petroleum diesel along with intake air at the flow rate of
4.6 liters per minute (lpm). The results are very promising. The fuel economy enhanced and
simultaneously engine exhaust emissions by the addition of oxygen enriched hydrogen gas with
change in inlet air charge temperature. In this investigation inlet air temperature was changed from
normal operating temperature of 300C to 350C and 250C. When the flow rate of the gas mixture
was 4.6 lpm with increased inlet air charge temperature of 350C, brake specific energy
consumption of the test engine got decreased from 14.8 MJ/kWh to 12.72 MJ/kWh, by a decrease
of 14.06%, and unburned hydrocarbon emission from 66 ppm to 51 ppm, by a decrease of 22.73%.
Smoke emission reduced substantially from 42 HSU to 29 HSU, by a reduction of 30.95%.
However; the NOX emission got increased from 420 ppm to 496 ppm, i.e., by 18.1%.