Selection and Development of a Particulate Trap System for a Light Duty Diesel Engine 920142

In order to meet progressively stringent regulations on particulate emission from diesel engines, GM has developed and tested a variety of trap oxidizer systems over the years. A particulate trap system for a light duty diesel engine has been selected and developed based on this experience, with particular emphasis on production feasibility. The system components have been designed and developed in collaboration with potential suppliers, to the extent possible.

The technical performance of this system has been demonstrated by successful system durability testing in the test cell and vehicle experience in computer controlled automatic operation mode. Although the system shows promise, its production readiness will require more development and extensive vehicle validation under all operating conditions.

ENVIRONMENTAL CONCERNS have led to the promulgation of progressively strict emission standards for both particulates and gaseous emissions from diesel engines since the early 1980's (1)*. The present and future known diesel emission standards are listed in Tables 1 & 2 for light and heavy duty truck applications respectively (2). As the stringency of future emission standards became known in the late 1970's, it was felt that some sort of aftertreatment would probably be needed. General Motors Corporation has had an intensive diesel particulate control program underway for a number of years to develop these systems (3,4,5,6,7). These investigations covered a wide variety of trap filter materials and regeneration systems, and involved analysis, design, development, and demonstration of these systems in the laboratory and on vehicles.

The objective of this program initiated in the late 1980's was to develop a production feasible particulate trap system using the best known technology. This paper describes the selection and development of a particulate trap system for the GM 6.2L diesel engine. Starting with the requirements for such a system, the system selection process, the development and description of the final system and major components are discussed. Most of the components were developed in cooperation with potential suppliers in production intent configurations. Later sections deal with the system performance characteristics and durability experience in the test cell and vehicles. The final section deals with the remaining concerns before such a system can be considered production ready.