Implementation of oxyhydrogen-enriched air on bio-ethanol fueled passenger car

Abstract

This study investigates the effects of oxyhydrogen-enriched air (OHEA) on the combustion characteristics and emissions of a bio-ethanol-fueled passenger car through a combination of simulation and experimental analysis. The engine’s fuel system was modified to operate independently on either gasoline or pure ethanol. An electrolysis system was integrated to supply HHO for ethanol-fueled operation. A detailed simulation model was developed to analyze the influence of HHO addition on in-cylinder combustion parameters. The results indicated that HHO enhanced engine performance by increasing in-cylinder pressure and temperature, while also shortening combustion duration. A steady-state chassis dynamometer experiment was conducted to validate these findings under controlled conditions. At full throttle (60–90 km/h vehicle speed range), the addition of OHEA led to an increase in the maximum brake power at the wheels by 3.74 % on average. Furthermore, brake-specific energy consumption (BSEC) decreased by 9.45 % when the test vehicle was fueled with ethanol-HHO compared to gasoline operations. Engine stability was significantly affected by fuel types. Compared to gasoline, ethanol-fueled operation exhibited greater instability, particularly at high throttle positions and elevated vehicle speeds, as reflected by an increase in the coefficient of variation of engine speed (COV_s) from 0.25 % for gasoline to 1.10 % for ethanol. However, OHEA significantly improved stability, reducing COV_s from 1.10 % to 0.60 %. Emission analysis showed that the introduction of ethanol and OHEA significantly reduced toxic emissions compared to gasoline-fueled operations during steady-state testing. Specifically, HC was reduced by 5.7 % to 43.8 %, CO by 3.2 % to 73.7 %, and NO_x by 10.9 % to 32.9 %. The use of ethanol, or the combination of ethanol and HHO, significantly reduces greenhouse gas emissions to the environment compared to gasoline use, with a reduction of up to 10.19 %. The results suggest that ethanol, particularly when supplemented with HHO, could serve as an effective alternative fuel strategy, balancing both environmental benefits and technical performance improvements. This approach may support broader efforts toward achieving carbon neutrality in the transportation sector.