Numerical simulation of three-way catalytic converter based on reverse flow
To improve the conversion rate of HC in natural gas/diesel dual fuel engines under low load,a three-way cata-lytic converter based on reverse flow was designed,and a mathematical model of the chemical reaction process of HC and CO catalytic conversion in a single channel was estab-lished,which was solved by ANSYS FLUENT software,while the numerical simulation of the working characteristics of the reverse flow three-way catalytic converter was carried out.Re-sults show that the designed reverse flow three-way catalytic converter can effectively control the emission of HC when the engine is under low load condition.The flow direction transfor-mation operation significantly improves the conversion rates of HC and CO compared to unidirectional flow.If the influence of shift mutation is ignored,the conversion rate of HC and CO is increased by 3.9%～6.4%and 2.0%～2.7%,respectively,while the conversion rate of NOx is relatively low,i.e.,only about 0.6%.The design of the switch time of the converter is not easy to be too large or too small,and it is recommended that the switch time is 10 s～15 s.With the increase of inlet velocity,the maximum temperature of the converter decrea-ses,while the emissions of HC and CO increase and the con-version rate decreases,but the impact on the conversion of NOx is small.
low loadnatural gas/dieselflow direction transformationthree way catalytic converterswitching timeconversion rate
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