Diesel Catalyst Aging Using a FOCAS HGTR, a Diesel Burner System, to Simulate Engine-Based Aging

摘要

The classical approach to prepare engine exhaust emissions control systems for evaluation and certification is to condition the fresh parts by aging the systems on an engine/dynamometer aging stand. For diesel systems this can be a very lengthy process since the estimated service life of the emissions control systems can be several hundred thousand miles. Thus full useful life aging can take thousands of engine bench aging hours, even at elevated temperatures, making aging a considerable cost and time investment. Compared to gasoline engines, diesel engines operate with very low exhaust gas temperatures. One of the major sources of catalyst deactivation is exposure to high temperature. The low temperatures observed in diesel engine systems can make it difficult to achieve elevated aging temperatures necessary to achieve accelerated aging effects, which results in longer aging times and/or more complex exhaust temperature elevation approaches to simulate targeted mileage conditions. Additionally, the larger diesel engines consume a considerable amount of fuel during the aging process, and fuel can be a major portion of the total aging cost. A burner-based aging system offers an alternative solution that provides higher exhaust temperatures, with lower fuel consumption compared to a diesel engine bench aging system. For gasoline aging test stands, equivalency in the aging impact between burner-based aging systems and gasoline-engine based aging systems has been demonstrated. This paper presents a diesel-fuel burner-based aging system that addresses the technical challenges of using a burner to simulate diesel exhaust and the validation of aging equivalency between the burner-based system and a diesel-engine bench aging stand. The operational cost effectiveness of burner systems compared to diesel systems is also explored.