Investigation of the Dual-Fuel Conversion of a Direct Injection Diesel Engine John S. Smallwood The transportation sector is the second largest energy-consuming sector in the United States. With heavy-duty vehicles comprising 20% of the sector and petroleum products being used as 93% of the sector's fuel, alternatives fuels continue to be investigated to offset petroleum usage. Natural gas is increasingly being considered as a fuel source due to its abundance in the Marcellus Shale Formation. Compressed natural gas (CNG) is a promising energy source for dual-fuel combustion. It appears to benefit the environment and the economy. With the ability to reduce oxides of nitrogen (NOx) emissions, carbon dioxide (CO 2) emissions, and particulate matter (PM) emissions, dual-fuel operation is environmentally viable. CNG costs less than petroleum derived diesel and would enable the United States to reduce its dependence on oil imports. Thus, dual-fuel operation promises to be economically practical. Dual-fuel operation reduces the amount of diesel fuel used during combustion and replaces it with an energy-equivalent amount of CNG. CNG is injected into the intake air stream during the intake stroke of the dual-fuel converted diesel engine's four-stroke cycle. CNG is utilized as the main energy source while diesel fuel is direct injected to initiate the ignition process due to its compression ignition characteristics. The objective of this work was to investigate dual-fuel combustion characteristics and resultant emissions to determine if the partial replacement of diesel fuel with CNG is an applicable technology in the transportation industry. To fulfill this objective, a dual-fuel capable 2005 Mercedes OM-460LA 12.8 liter engine outfitted with incylinder pressure and exhaust emissions measurement capabilities was operated at steady-state conditions. Combustion characteristics and resultant emissions were compared between the dualfuel and diesel operations. To certify a dual-fuel conversion kit with the Environmental Protection Agency's (EPA's) Clean Alternative Fuel Conversion Program, research and development work was also completed on a 2005 Mack AC-460P 12.0 liter engine. Exhaust emissions were collected over steady-state and transient conditions. In-use operation cost comparisons and fuel efficiencies between dual-fuel operation and diesel-only operation were completed with the certified conversion kit. The combustion characteristics that most affected emission formations were decreased combustion efficiencies (≤ 39.9%) and decreased maximum in-cylinder gas temperatures (≤ 15.2%). With the dual-fuel conversion kit meeting certification requirements, NOx emissions decreased for steady-state (10.1%) and transient (7.29%) operations while PM emissions increased for steady-state (14.2%) operation and decreased for transient (27.4%) operation. CO 2 emissions decreased for steady-state (8.87%) and transient (7.81%) operations while carbon monoxide (CO) emissions increased for steady-state (754%) and transient (836%) operatio...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.