Numerical study on emission characteristics of a diesel engine fuelled with diesel-spirulina microalgae-ethanol blends at various operating conditions

Abstract

The exhaust gas emissions from a compression ignition (CI) engines are mostly depend on the nature of fuel mixture, combustion chamber, and injection parameters. Higher combustion temperature, which leads to oxides of nitrogen (NOX) emission. In the present study, an engine of single-cylinder, direct cooling was operated at 1500 rpm speed with variable engine loads. Numerical simulation is performed using blends of diesel, spirulina microalgae biodiesel (BSP20, BSP40, and BSP100), and diesel-spirulina microalgae biodiesel – ethanol (DSP80E20). In this study, a variation in fuel injection timings (15.5° b TDC – 27.5° b TDC), nozzle diameters (0.15 mm − 0.4 mm), and swirl ratios (0.5–3.0) are investigated for emission characteristics (NOX, particulate matter, smoke and summary of emission). Results indicated that by increasing nozzle diameter (ND), injection timing (IT) and swirl ratio (SWR) the NOX emission is increased noticeably. Additionally, increasing ND, IT and SWR leads to higher particulate matter and summary of emissions for diesel and DSP80E20 but lower for BSP20 and BSP40 blends. The reduction in NOX emissions using DSP80E20, BSP20 and BSP40 blends as compared to diesel fuel. The results showed that at 0.25 mm (nozzle diameter) of spirulina microalgae, and ethanol-blended fuel showed better response. Smoke emission reduced with spirulina microalgae and ethanol due to the higher oxygen percentage within the blends. A significant decrease of particulate matter and summary of emission was also observed.