Theoretical and Experimental Analysis of Engine Performance and Emissions Fuelled with Jojoba Biodiesel

Over many decades, isolated regions (e.g., islands, rural and remote areas) have heavily relied on diesel engine for producing power and energy. However, due to depleting fossil fuels and concerning emissions, biodiesels could be the substitute for diesel in power generation sectors. This study developed a single-zone thermodynamic model to predict the engine performances such as brake power (BP), torque, brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC) and ignition delay (ID) times for diesel and jojoba biodiesel. The experiments were conducted on a fully automated, 4-cylinder, 4-stroke, liquid-cooled direct injection 3.7-L diesel engine fueled with diesel (D100) and three jojoba blends (JB5, JB10, and JB20) to validate the model. The performance simulation results agreed with experimental data for all tested fuels at 1200 to 2400 rpm speed and 25%, 50%, 75%, and 100% loading operation. The minimum error (3.7%) was observed for BP for D100 at 2000 rpm and 100% load, and the maximum error (19.2%) was found for JB10 at 1200 rpm and 25% loading operation. As load increases from 25 to 100%, the BSFC and torque difference between diesel and JB20 decreases from 10 to 6.5 and 9 to 6%, respectively. A shorter ID time was observed in JB5 compared to JB10 and JB20. Furthermore, a significant reduction was observed in CO (7.55%) and HC (6.65%) emission for JB20 at 25% and 1200 rpm compared to diesel fuel; however, NOx emission was increased up to 10.25% under any given conditions

Thermodynamic analysis of diesel engine ignition delay under low load conditions

In recent decades, renewable energies (e.g., wind and solar) were introduced to reduce the dependency of diesel generation in remote areas and islands power systems. However, diesel generation cannot be eliminated entirely because of the uncertainty and intermittent of renewable sources. In this regards, low load diesel operation (below 30% of maximum rated power) is considered to achieve highest possible penetration of renewable energy in the hybrid (e.g., renewable diesel) power system for isolated locations. Ignition delay (ID) is one of the key parameters to affect engine response and performance in the power generation sectors. This study investigated the diesel engine ignition delay for different load operations from 15% to 100% under different engine speed ranging from 1500 rpm to 2100 rpm. From this analysis, it was found that ignition delay time increased with a decrease in engine load and decreased with an increase in engine speed. The results showed that at 15% and 25% loading conditions ignition delay times are 1.16 and 0.98 ms for 1500 rpm, 0.98 and 1.07 ms for 1800 rpm, and 1.10 and 0.92 ms for 2100 rpm engine speed operation. These results indicate that the change of engine load and speed did not significantly affect ignition delay

Theoretical and Experimental Analysis of Engine Performance and Emissions Fuelled with Jojoba Biodiesel

Over many decades, isolated regions (e.g., islands, rural and remote areas) have heavily relied on diesel engine for producing power and energy. However, due to depleting fossil fuels and concerning emissions, biodiesels could be the substitute for diesel in power generation sectors. This study developed a single-zone thermodynamic model to predict the engine performances such as brake power (BP), torque, brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC) and ignition delay (ID) times for diesel and jojoba biodiesel. The experiments were conducted on a fully automated, 4-cylinder, 4-stroke, liquid-cooled direct injection 3.7-L diesel engine fueled with diesel (D100) and three jojoba blends (JB5, JB10, and JB20) to validate the model. The performance simulation results agreed with experimental data for all tested fuels at 1200 to 2400 rpm speed and 25%, 50%, 75%, and 100% loading operation. The minimum error (3.7%) was observed for BP for D100 at 2000 rpm and 100% load, and the maximum error (19.2%) was found for JB10 at 1200 rpm and 25% loading operation. As load increases from 25 to 100%, the BSFC and torque difference between diesel and JB20 decreases from 10 to 6.5 and 9 to 6%, respectively. A shorter ID time was observed in JB5 compared to JB10 and JB20. Furthermore, a significant reduction was observed in CO (7.55%) and HC (6.65%) emission for JB20 at 25% and 1200 rpm compared to diesel fuel; however, NOx emission was increased up to 10.25% under any given conditions

Techno-Economic Performance and Sensitivity Analysis of an Off-Grid Renewable Energy-Based Hybrid System: A Case Study of Kuakata, Bangladesh

Hybrid renewable energy sources (HRES) are increasingly being utilized to meet global energy demands, particularly in rural areas that rely on diesel generators and are disconnected from the utility grid, due to their environmental and human health benefits. This study investigates the performance of an off-grid, hybrid PV/diesel generator/battery system for a decentralized power plant in Kuakata, Bangladesh, meeting a load demand of 3000 kWh/day with a 501.61 kW peak load demand. HOMER Pro (hybrid optimization model for electric renewable) software (version 3.11) was used to simulate and optimize system operations utilizing real-time solar radiation and load profile data from that location. This study also includes a sensitivity analysis of the off-grid HRES system under different electrical load demands, project longevity, and derating variables. The results reveal that CO2 emissions have potentially decreased by more than 30% and over 10 tons per year, respectively, when compared to traditional power plants. The optimized system’s net present cost (NPC) was determined to be around USD 5.19 million, with a cost of energy (COE) of USD 0.367 per kWh per unit with a 100% renewable component. Furthermore, the current study’s findings are compared to previous research that has resulted in an economical hybrid renewable energy system with an affordable COE. The hybrid energy system under consideration might also be applicable to other parts of the world with comparable climate conditions