Search Results

Hybrid electric powertrain can be a promising and cost-effective technology to meet forthcoming emissions regulations. However, the hybridization of a conventional powertrain remains a complex task. According to their functions, hybrid powertrains can be classified into full-hybrid, mild-hybrid and micro-hybrid, of which micro-hybrid system is regarded as the most cost-effective solution for current regulations. Although a micro-hybrid system employs relatively simple new functions, such as stop/start and regenerative braking, to achieve the target fuel economy with reasonable cost, the engineer must consider many practical aspects in order to deliver a solution which is robust, effective and easy to understand for customers. In this paper the development of a belt-driven integrated starter generator (BISG) micro-hybrid system for a light-duty commercial vehicle application is presented.

The low exhaust gas temperatures experienced on light duty Diesel vehicles present a very challenging environment for the successful operation of catalytic aftertreatment. To meet the future more severe legislation, Diesel engines are being developed with greater combustion efficiencies and advanced fueling control. These engine developments may produce lower particulate matter (PM) and nitrogen oxides (NOx) emissions, but increased hydrocarbon (HC) and carbon monoxide (CO) emissions may occur. As a result of these engine changes exhaust gas temperatures may reduce still further. These factors demand catalysts with high oxidation activity at low temperatures. This paper reviews oxidation catalyst technology developed for light duty Diesel vehicles and the factors affecting their performance. Results obtained on synthetic gas rigs, bench engines and vehicles are presented. A discussion oh the effect of the level of sulfur (S) present in Diesel fuel on aftertreatment is given.