A Study On The Rapid Aging Test Method For Three Way Catalytic Converter

It is paid more attention to the entiroment deterioration and emission standardst, and the three-way catalyst technology has been a necessary approach for the exhaust after treatment of gasoline engine. Besides, the catalyst is required to have greater efficiency in the actual road conditions and standards, and the testing and evaluating method is attacked more attention through the entire process of vehicle after treatment and manufacture.In order to test and evaluate the catalyst more effectively in test-room, the L cycle is developed based on the FOCAS system. This cycle mode is different from the mode of several segments rapid aging cycle, which is taken to evaluate catalyst by the some institutes or corporations. It is similar with the simple fuel-cut cycle and is more easily to operate. Besides, it has fewer requirements to the engine and dynamometer.Compared the RAT-A cycle in the FOCAS system with the same cycle in the engine, it shows that similar temperature fields can be gotten from both of the FOCAS system and engine bench, and the aging effect in the FOCAS system is similar to that in the engine bench. The Statistical result shows there are not difference to the aging effects of HC and NOx between the both aging methods, and the emissions also is coincident once the aged catalysts are same. It presents that the FOCAS system has the same aging impact to catalyst as the engine bench.In order to get more suitable rapid aging test parameters, the analysis about parameters of heat aging and non-heat aging is implemented and the parameters of Arrhenius equation are settled. The exhaust temperature is improved in L cycle to accelerate the catalytic reaction and make the catalyst aging more heavily and more rapidly. Using this cycle of 180s, it can reduce the frequency of the engine periodic running condition and decrease the loss of engine and dynamometer though there may be less impact to the catalyst deterioration from the cycled A/F turned from rich and thin. The similar heat deterioration with that gotten under nation standard cycle can be finished in L cycle. There is higher inlet temperature in L cycle and the aging is stronger. Currently, many catalysts are often two sections. As the first section catalyst is very close to the exhaust manifold, it will endure higher temperature and more frequent variation of A/F, and the L cycle is more effectual to evaluate the first section of the two section catalyst.