For cleaner exhaust of a high performance motorcycle: A macroscopic comparative study of catalytic converters under world-wide motorcycle test cycle

Abstract

Considering the noble metals resources used in Three-way catalysts are extremely limited, traditional Three-way catalysts can no longer meet the increasingly stringent emissions control standards economically. For more efficient emissions control, we first time to perform a multi-parameters comparative investigation on catalytic converter design for high performance motorcycles with considerations of converter’s structure/size, layout and engine working status under World-wide Motorcycle Test Cycle to explore novel design methods of Three-way catalysts. Based on the several models designed for test, the original transient emissions are measured to explore engine’s working performances and factors that impact raw emissions, the integrated effect of converter structure/size and layout on emissions conversion efficiency is also explored. In this study, Model 1 is double catalytic structure while Model 2 and Model 3 are single structure, detailed parameters about these models are expressed as the format “Length, Diameter or long/short axis for ellipse, Cell density” as: Model 1-front: 42 mm, 123 mm, 200 cpsi; Model 1-rear: 123 mm, 95/65 mm, 300 cpsi; Model 2: 85 mm, 100 mm, 400 cpsi; Model 3: 82 mm, 130 mm, 300 cpsi. Catalytic conversion efficiency of CO, THC and NOx are ranked as Model 3: 88.13% > Model 1: 85.95% > Model 2: 84.89%, Model 1: 93.73% > Model 3: 89.76% > Model 2: 85.79% and Model 1: 98.27% > Model 2: 92.58% > Model 3: 87.05%, respectively. Small-size catalytic converters have quicker warm-up and poorer heat preservation capacity, that’s why Model 2 has the highest catalytic efficiency for CO in cold stage and the lowest overall, Meanwhile, Model 2 has the best trade-off performance. We hope to provide useful knowledge that guides the converter design/application.