Enhancement of catalytic converter performance to reduce cold start emissions with thermal energy storage – An experimental study

A “Thermal Energy Storage” (TES) system can assist in solving the cold start emission problem associated with the catalytic converter. “Phase change materials” (PCMs) can be used in the TES system to absorb heat from the exhaust gases, liquefy it and store it as latent heat. This makes it possible to store the exhaust heat during the engine running conditions and to release it on the catalyst substrate during the off-engine and low temperature start. A catalytic converter is integrated with a TES unit with Mg70Zn24.9Al5.1 as PCM having melting point in range of 310 °C & 157 kJ/kg as heat of fusion. This paper presents Experimental investigation of Catalytic Converter for exhaust temperature, conversion efficiency with and without TES unit. The investigation includes the heat storage and retention time during engine operation. Test cycle of 150 min with each load were run including idle events in between at 2000 rpm for different load conditions. Results showcased maximum average conversion efficiency improvement for 60 %, 53 % and 30 % for HC, NOx and CO respectively at No load condition during cold start. Heat Retention time was found higher for high loads, 100 % & 75 % load temperature was observed to remain above 100 0C for nearly 350 min. © 2023