Semester

Fall

Date of Graduation

2011

Document Type

Thesis

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Mechanical and Aerospace Engineering

Committee Chair

Gregory Thompson

Abstract

The people of the world have become conscious of the effects human beings are having on the earth. This awareness has spawned a willingness to regulate the amount of pollution from fossil fuel combustion that human beings place on the environment. In the United States, the Environmental Protection Agency (EPA) and the California Air Resources Board (CARB) determine and regulate the emissions standards of on-and-off road engines through emissions testing. As emissions standards become more stringent, the demand to retain the efficiency of these engines is necessitated by pending fuel economy standards and customer acceptance. Diesel engines are implemented in various applications and range from passenger cars to heavy duty transportation of goods in the form of tractor trailers and trains, as well as most off road heavy duty equipment used for construction and farming due to their relative high thermal efficiency. However, diesel engines also produce significant particulate matter (PM).;One form of technology that can help diesel engines meet the new stringent emissions regulations is the diesel particulate filter (DPF). A DPF is used to reduce engine-out diesel PM on the order of 90%, by mass, by trapping the organic and inorganic PM and then oxidizing the organic matter at a later time. The technology has been implemented in various applications and has been a proven method of controlling PM for on-road passenger and heavy-duty diesel-fueled vehicles. However, the exhaust stream of a diesel engine is a volatile environment with pressure and temperature gradients that make the implementation and operation of DPFs a challenge. Additionally, it is necessary to eliminate the accumulated PM that deposits in the filter media. Many different methods of oxidizing the organic fraction of PM trapped within the DPFs filter media, also referred to as regenerating, have been developed.;The focus of this study was electrically-induced burn of PM captured on sintered metal fiber media. The findings of this study concluded that there are specific parameters that should be considered when constructing a control strategy for an electrically induced regeneration scheme. These parameters include the operational backpressure limitations of the engine as well as the PM production from the engine. A diesel oxidation catalyst (DOC) showed benefits for reducing the hydrocarbons in the emissions stream as well as contributing to the PM reduction efficiency by up to 30%. It is recommended that the DPF should maintain an operational back pressure below 120 in H 2O. This maintained a soot concentration which increased the filtration efficiency above 90%. Actuating the dual chambers on a higher frequency and limiting the length of burn to retain the soot buildup and backpressure resulted in filtration efficiencies levels above 90%.

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