Ignition-timing-dependent efficiency and emission trade-offs of HHO-assisted gasoline–bioethanol blends in a spark-ignition engine under lean operation
Artykuł w czasopiśmie
MNiSW
140
Lista 2024
| Status: | |
| Autorzy: | Rimkus Alfredas, Kozłowski Edward, Matijošius Jonas, Zimakowska-Laskowska Magdalena, Cieplak Tomasz |
| Dyscypliny: | |
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| Rok wydania: | 2026 |
| Wersja dokumentu: | Drukowana | Elektroniczna |
| Język: | angielski |
| Wolumen/Tom: | 215 |
| Numer artykułu: | 153853 |
| Impact Factor: | 8,3 |
| Scopus® Cytowania: | 0 |
| Bazy: | Scopus |
| Efekt badań statutowych | NIE |
| Materiał konferencyjny: | NIE |
| Publikacja OA: | NIE |
| Abstrakty: | angielski |
| This research investigates the influence of hydrogen and oxygen (HHO) gas on the ecological and energy efficiency characteristics of a spark ignition (SI) engine, employing a range of fuel blends, such as gasoline–bioethanol blends (E10 and E70). A systematic exploration was undertaken at a steady velocity of 2000 rpm and a throttle opening of 15%, spanning a broad range of excess-air ratios (λ = 1.0–1.4) and variations in ignition timing (IT), with the aim of assessing the impact of HHO on brake thermal efficiency (BTE), fuel economy, and emissions. The HHO gas blend, produced by water electrolysis, was supplied at 3.7 L min−1, corresponding to a hydrogen delivery rate of 0.0133 kg h−1 and a hydrogen fraction of about 1/400 by volume in the inducted air charge. The HHO stream was introduced downstream of the throttle into the intake-manifold plenum and oriented approximately 90° to the main intake flow direction to promote rapid turbulent mixing and avoid localized stratification. Polynomial regression models were developed to describe the dependence of BTE and normalized pollutant emissions (CO/BTE, CO2/BTE, HC/BTE and NOx/BTE) on IT for each fuel blend and λ value, yielding high coefficients of determination (R2 up to 0.98) and statistically significant fits (p < 0.001). At λ = 1.3, regression-based optimization shows that HHO addition shifts the BTE-optimal ignition timing by approximately 1.4–1.6 °CA toward earlier phasing for both E10 and E70 fuels, while maintaining comparable or slightly improved brake thermal efficiency and simultaneously reducing CO and HC emissions on a brake-specific basis. The results demonstrate that, under lean blend conditions (λ ≥ 1.2), the incorporation of HHO consistently shifts the optimal IT to slightly lower advance values and enhances BTE compared with operation without HHO. Under the investigated operating conditions, the combined application of ignition timing optimization and HHO supplementation increased the brake thermal efficiency by up to 17% compared to the baseline gasoline operation. At the same time, the use of HHO reduces CO and HC emissions per unit brake energy and lowers the CO2/BTE ratio, indicating more efficient utilization of the fuel chemical energy. The combination of ethanol-rich E70 gasoline and HHO gas demonstrated an optimal balance between elevated brake thermal efficiency and minimized emissions of carbon monoxide, hydrocarbons, and carbon dioxide during lean-burn operation, thereby affirming its viability as a sustainable approach to enhance engine performance while mitigating environmental repercussions. The amalgamation of real-time emission analysis with programmable control systems afforded a dependable and precise evaluation of combustion dynamics, thereby clarifying the significance of HHO gas as a beneficial and ecologically sustainable adjunct for internal combustion engines. |
