A three-wheeler is a symbol of mobility at low cost for a common man in India. Due to high loading compared to its 2-wheeler counterpart, the 3-wheeler emit higher emissions and serious efforts are being made by the manufacturer to minimize the emissions.
ARAI and Emitec have undertaken a Technology Demonstrator Project to investigate the application of metallic substrates and Emitubes for a typical carburetted 2-stroke 3-seater 3-wheeler with an aim to introduce a cost effective practically viable option of reducing exhaust emissions to meet INDIA 2000 emission norms. Now-a-days, there are 3-wheelers available which are offering lower emissions levels. It was the intention of the authors, not to use such a clean vehicle for a better demonstration of the efficiency of current catalyst technology. Here, a 3-wheeler manufactured in 1996 has been selected, for which a converter is designed employing a software developed by Emitec.
The paper highlights the effects of adopting catalytic converter in the exhaust system with various combination of metallic substrates, cylindrical Emitubes and conical Emitubes. Different configurations are tested for emission performance, conversion efficiency, change in exhaust temperature, rise in back pressure, drop in engine performance and durability. Cold start emission employing Indian driving cycle prescribed as per INDIA 2000 emission norms are reported. The effect of insulation of exhaust header pipe, carburettor settings and catalyst formulation on the emission are studied.
After comparing four configurations, the best configuration is selected and optimised. The optimized solution with best catalyst formulation helps to meet INDIA 2000 cold start mass emission norms with 75% reduction in CO and 60% reduction in HC+NOx. Road endurance trial has been conducted on a selected road profile to understand the efficiency deterioration of the catalytic converter. 10,000 kms of running has been completed and the results are found to be promising.