EXPERIMENT (Cont.)

The experiment was to see if there would be immediate performance improvements to the engine due to the Militec-1 reducing friction on the bearing, gear, and cylinder surfaces of the engine. A reduction in friction in a diesel engine would increase its mechanical efficiency. This should show up in the heat balance as an increase in the brake thermal efficiency and a corresponding decrease in the energy loss to the cooling water and to other losses. The energy loss to the exhaust gas should not be effected.

ANALYSIS

The calculated values of the historical data reveal that the engine's brake thermal efficiency increased steadily from 28% at an output of 130kW to just under 36% at an output of 250kW. The corresponding brake specific fuel consumption (bsfc) decreased from a value of 0.50 Ib/bhp-hr at 130kW to a value of 0.393 Ib/bhp-hr at 250kW. This is typical of what one would expect to see in efficiency and fuel consumption as the engine output is increased. Diesel engines are most efficient at around 80% of their rated output.

The post-Militec data reveals that at an output of the brake specific fuel consumption is averaging 0.45 Ib/bhp-hr This is lower than what the trend in the historical data would suggest even though the value of the bsfc at the 148kW run was also 0.45 Ib/bhp-hr This would lead one to conclude that the engine is running with a lower specific fuel consumption than it was before. At an output of 250kW the average bsfc is now 0.381 Ib/bhp-hr. Comparing this to the historical value of 0.393 Ib/bhp-hr reveals a decrease of 3% in fuel consumption.

The heat balance results are not conclusive. The "Percent of 'Heat In' to BHP" is the same as brake thermal efficiency. It experiences an increase of about one percent from 35.7% to an average of 36.8%. The "Percent of 'Heat In' to Exhaust Loss" is essentially unchanged at 22%. The "Percent of 'Heat In' to Cooling Water Loss" has experienced a decrease but it is all showing up as a corresponding increase in the "Percent of 'Heat In' to Other Losses". The measurement of the raw water flow rate could be the source of the problem.

CONCLUSION

The addition of Militec-1 to the engine lubricating oil of the Waukesha marine diesel generator set at the U.S. Merchant Marine Academy has produced a reduction of specific fuel consumption of three percent at an output of 250kW. This result is based on the average of the three readings taken after the addition of Militec-1 to the lubricating oil and one reading taken before. In conclusion, the data shows that the engine is experiencing a decrease in its specific fuel consumption due to the reduction of friction by the addition of MILITEC-1.

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