|SOLOIU, VALENTIN - Georgia Southern University|
|DAVOUD, SHERWIN - Georgia Southern University|
|MUINOS, MARTIN - Georgia Southern University|
|WATSON, CHANNING - Georgia Southern University|
|MOLINA, GUSTAVO - Georgia Southern University|
|HARP, SPENCER - Georgia Southern University|
|KOEHLER, BRIAN - Georgia Southern University|
|HEIMBERGER, JULIA - Georgia Southern University|
|JANSON, MARCIS - Wayne State University|
|Butts, Christopher - Chris|
Submitted to: International Journal of Fuels and Lubricants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/23/2015
Publication Date: 4/14/2015
Publication URL: http://dx.doi.org/10.4271/2015-01-0806
Citation: Soloiu, V., Davoud, S., Muinos, M., Watson, C., Molina, G., Harp, S., Koehler, B., Heimberger, J., Janson, M., Butts, C.L. 2015. Performance of an IDI Engine Fueled with Fatty Acid Methyl Esters Formulated from Cotton Seeds Oils. International Journal of Fuels and Lubricants. doi: 10.4271/2015-01-0806.
Interpretive Summary: A study was conducted to evaluate the performance of an indirect injection diesel engine fueled with biodiesel made from cottonseed oil. Cottonseed biodiesel was blended with #2 ultra low sulfur diesel (ULSD) fuel at rates ranging from 20 to 50%. Engine performance with the cottonseed biodiesel blends was compared to the performance using 100% diesel fuel. NOx emissions was essentially the same for all blends of cottonseed biodiesel and 100% diesel fuel and increased as the load increased. Soot and smoke decreased as the percent cottonseed biodiesel increased in the blend, and increased with as the load on the engine increased. Both the thermal and mechanical efficiency increased with engine load. The energy specific fuel consumption for the 50% blend cottonseed biodiesel was 4% lower than that using 100% ULSD.
Technical Abstract: This study evaluates the performance of an indirect injection (IDI) diesel engine fueled with cottonseed biodiesel while assessing the IDI engine multi-fuel capability. Millions of tons of cotton seeds are available in the southeast of the USA every year and they contain oils that can be transesterified. An investigation of combustion, emissions, and efficiency was performed in this study, using mass ratio blends of 20-50% cottonseed biodiesel (CS20 and CS50) in ultra-low sulfur diesel #2 (ULSD#2). Each investigation was run at 2400 rpm with loads of 4-6.3 IMEP and compared to the reference fuel ULDS#2 at respective loads. The experimental engine used in the testing was an IDI compression ignition engine with a 77mm bore and a triple vortex auxiliary combustion chamber. The biodiesel had a cetane number with 5 units higher than ULSD and the ignition delay ranged from 0.8-0.93ms across the blends, and the believed reason is due to the high turbulence and temperature of the separate combustion chamber. The maximum combustion pressure increased with the load but stayed constant with an increase in concentration of biodiesel. The maximum heat release rate increased with load but at constant IMEP there are similar trends for all fuel blends. The maximum heat release rate at 6.3 bar IMEP load for ULSD was 16.7 J/deg and increased for CS50 at 17.1 J/deg. The maximum temperature increased by approximately 100K with each IMEP bar increase in load. The concentration of biodiesel did not affect the maximum volume-averaged gas temperature compared to ULSD#2. The radiation heat flux ranged from 0.6 – 1.0 MW/m2, the convection heat flux’s ranged from 2.4 - 2.6 MW/m2, and the total heat flux ranged from 2.8 – 3.3 MW/m2 and all values increased with increased load. The energy specific fuel consumption (ESFC) for ULSD#2 was 9.3MJ/kWh and decreased by 4.4% for CS50 at 6.3 bars IMEP. The indicated thermal efficiency of the engine ranged from approximately 45%-50% while the mechanical efficiency ranged from 71-81% both increasing with the engine load. For all fuel blends almost constant NOx emissions were observed and nearly linear increase with increase in load when compared to ULSD#2 and the soot and smoke decreased with the amount of oxygen in the biodiesel blends and increased with load. Overall, the study confirmed that concentrations of up to 50% cottonseed biodiesel in ULSD are effective at maintaining performance and efficiency of a small IDI engine.