Effects of nozzle geometry, compression ratio and cerium oxide nanoparticles on algae biodiesel performance in a VCR diesel engine with hydrogen addition

This paper discusses an exploratory analysis of performance and emissions characteristics of a variable compression ratio (VCR) diesel engine using various compression ratios, nozzle hole configurations, and injection timings. Results will be employed to further elucidate interactions among those parameters as well as their influence upon the operation efficiency and environmental output. An engine was tested on the B20 biodiesel blend from the transesterification of algal oil. The sample, which contained nano-additives with cerium oxide (CeO 2 ) at a concentration of 75 ppm, underwent extensive analysis using scanning electron microscopy and energy dispersive X-ray analysis (FTIR). The study included different compression ratios such as 16:1, 17:1, 18:1, and 19:1, utilizing nozzle designs with hole diameters of 2, 3, 4, and 5 mm. Additionally, it also examines the effects of hydrogen injection at time intervals of 3, 4, and 5 ms, aiming to comprehend the interaction between these parameters and their impact on the performance outcome. The presence of CeO 2 75 ppm resulted in a significant reduction in emissions, as well as improved combustion efficiency. The configuration resulted in a 6.1% improvement in brake thermal efficiency (BTE), as well as a decrease in brake specific fuel consumption (BSFC) from 250 g/kWh to 200 g/kWh. Improving the number of holes in the nozzle revealed a drop in the temperature of the exhaust gas up to 250°C. Reduced nitrogen oxide (NO X ) emissions and improved cylinder pressure accompanied these decreases, thanks to the increased heat release rates generated by hydrogen addition. The addition of CeO 2 nanoparticles to the B20 blended fuel, along with modifications to the nozzle hole design and hydrogen injection, not only reduces emission values but also lowers fuel consumption, lowers exhaust gas temperature (EGT), and improves combustion efficiency.