Emissions From a Diesel Engine Operating in a Dual-Fuel Mode Using Port-Fuel Injection of Heated Hydrous Ethanol

Abstract

Aftermarket dual-fuel injection systems in diesel engines using hydrous ethanol have been developed as a means to lower emissions from older diesel-powered equipment. However, our previous work has shown that the emissions benefits of currently available aftermarket intake fumigation injection systems can be inconsistent with manufacturer claims. Our current study evaluates a newly developed aftermarket dual fuel system that incorporates a novel fuel heating system and port fuel injection (PFI). This paper describes an experimental investigation of engine-out emissions from a John Deere 4045HF475 Tier 2 engine with port injection of 180 proof (90% ethanol by volume) hydrous ethanol. The engine was retrofitted with a custom fuel heat exchanger to heat the hydrous ethanol to a range of 46–79°C for helping to improve fuel vaporization in the intake port. PFI duration was controlled using engine speed and throttle position as inputs to achieve a desired fumigant energy fraction (FEF), defined as the amount of energy provided by the hydrous ethanol based on lower heating value (LHV) over the total fuel energy provided to the engine. Data was collected over a range of FEF with direct injected diesel for eight operating modes comparing heated versus unheated hydrous ethanol. Results of the study indicate that as FEF increases, NO emissions decrease, while NO2, CO, THC, and ethanol emissions increase. In addition, it was found that preheating the ethanol using engine coolant prior to injection has little benefit on engine-out emissions. The work shows that the implemented aftermarket dual-fuel PFI system can achieve FEF rates up to 37% at low engine load while yielding modest benefits in emissions.

Hydrous Ethanol Steam Reforming and Thermochemical Recuperation to Improve Dual-Fuel Diesel Engine Emissions and Efficiency

“…Overall, soot emissions decreased drastically, reaching near 90% reduction from CDC levels at high FEF. This result is somewhat contrary to our earlier hydrous ethanol PFI work [1][2][3] which showed that soot emissions remained high even at significant FEF. With reformed ethanol, as FEF increased, engine combustion was more premixed with significantly less directly injected diesel.…”

“…However, the high load condition experienced only a minor increase before decreasing, indicative of the high CE seen during this condition, providing further evidence that ISR operation is most beneficial at high loads. Unlike our previous work with hydrous ethanol [1][2][3], no unburned ethanol was present at engine outlet conditions. Instead, THC emissions consisted mainly of methane, depicted in Figure 6 and smaller amounts of acetaldehyde and formaldehyde.…”

“…Our previous work [1][2][3] explored the use of hydrous ethanol in diesel dual-fuel combustion modes using a stock engine fuel injection calibration to determine how effective such a system could be if implemented as an aftermarket solution. When introduced through port fuel injection (PFI), hydrous ethanol achieved stable combustion with negligible impact on engine performance and up to 60% fumigant energy fraction (FEF), defined as the ratio of energy provided by the ethanol over total fuel energy.…”

Experimental Study on Evaporation and Micro-Explosion Characteristics of Ethanol and Diesel Blended Droplets

“…Hwang, and W.F. Northrop [50], while e-diesel can reduce particulate emissions, there remains controversy over its effects on NOx, CO, and HC emissions. Additionally, the low flash point of e-diesel could pose safety challenges.…”

Innermotorische Effizienzsteigerung luftansaugender und gemischansaugender Dual-Fuel Brennverfahren

“…Beim Übergang vom klassischen Dual-Fuel hin zum RCCI-Betrieb konnten ein weiterer Rückgang der Stickstoffoxid-Emissionen beobachtet und auch der Kohlenstoffmonoxid-sowie der Kohlenwasserstoffausstoß gesenkt werden. Nord et al[62] untersuchten die Saugrohreinbringung von vorgewärmtem, flüssigem Ethanol mit 10 % Wassergehalt. Durch die Vorwärmung wurde die maximal mögliche Substitutionsrate bei niedriger Last erhöht, jedoch bei höheren Lasten reduziert.…”