Study On Aging Test Of Catalytic Converter For Vehicle

In the face of the problem of atmospheric environment worsening and the increasingly stringent emission regulations, three-way catalytic converter technology has become an important measure to reduce automobile exhaust pollution. Nevertheless, the performance of the three-way catalytic converter will be gradually deteriorated as time goes on, which leads to the decrease of the conversion efficiency and the increase of the vehicle emission. Therefore, it is extremely important to study the durability of catalyst.First of all, based on the aging mechanism of catalyst and real road condition of vehicle, rapid aging test of two same samples of catalytic converter (A and B) are carried out by the four-stage aging cycle (GMAC-875 cycle) and standard bench aging cycle (SBC cycle) respectively for 160 hours in this thesis. Then the performance indexes of catalyst before and after aging are compared and analyzed in order to study the deterioration degree of two aging cycles on the catalytic converter.Secondly, the vehicle emission test is done on the aged A and B installed on a real vehicle. And emission results are compared and analyzed so as to study the deterioration degree of two aging cycles on the catalytic converter. Then verify the reliability of the test results by comparing with the conclusion of rapid aging test on the engine bench evalution.In the end, the 160,000 km durability test is carried out with the same catalytic converter C which is used in the bench rapid aging test above. The results and performance of catalyst in the durability test are analyzed. Then the performance indexes of catalyst are compared and analyzed after 160 hours bench aging test and 160,000 km durability test through the light-off temperature characteristic test and A/F characteristic test. And the correlation of two aging methods is studied by the comparison of emission results.Results show:1) Compared with sample B, Sample A’s increased value of light-off temperature on CO, THC, and NOx is 13C°,11C°, and 4C° higher respectively. And its decreased value of efficient window is 0.02 more. Sample A’s catalytic converter has a higher level of vehicle emissions of THC, NMHC, NOx, and CO by 0.004g/km,0.003g/km,0.006g/km, 0.03g/km. It is proved that GMAC-875 cycle has a higher deterioration degree than the standard bench cycle.2) Sample A’s light-off temperature is 10℃ higher than that of sample C while its efficient window of A/F ratio is 0.02 less than that of sample C. Sample A has a 10% larger emission value than sample C. It is proved that rapid aging by GMAC-875 cycle for 160 hours has a slightly larger deterioration degree on the catalytic converter.