Knowledge Bank

As concern for the environmental issues become more severe, emission regulations are becoming more stringent. To meet increasing demands of emissions regulations, industrial leading auto maker try to replace the conventional gasoline vehicles by renewable vehicles such as EVs (electrical vehicles) and PHEVs (Plug-In Hybrid Electrical Vehicles). Although these renewable vehicles decrease the annual emission greatly, the manufacturing cost and operational range are primary constrains to prevent the mass production in large scale. On top of this, TWC (Three-Way Catalyst) is the current solution to reduce the emission on the conventional vehicles. But it is limited during the cold start because it can be functional only if the temperature is above light-off temperature. To eliminate the limitation of operational temperature, EHCs (Electrically Heated Catalysts) have been proposed as a solution. This technology can be particularly helpful for PHEVs to reduce the emissions following a cold start event. One challenge for implementation on PHEVs is that they typically have low current capability in the 12-volt system that supplies the EHCs. EHCs often require more than 100 amps from a 12-volt system for 50-60 seconds making it difficult to use in a PHEV. This research is focused on investigating the relationship between emission conversion efficiencies and light-off temperature to achieve the desired emission reduction goal. A wide range of light-off temperature with constant power supply and air mass flow rate are tested to study thermal and chemical characteristics of the EHC. Emissions data during these tests are collected and studied to determine the best possible solution for lowering emissions while staying within the constraints of the 12-volt system. These results are used to develop a control strategy for OSU’s EcoCAR vehicle which will compete in a national competition in May of 2017.