Search Results (86)

The rapid development of electric transport necessitates efficient energy storage and redistribution in traction systems. A key challenge is the utilization of regenerative braking energy, which is often dissipated in resistors due to network saturation and limited consumption capacity. The paper addresses the problem of inefficient energy utilization in electric rail vehicles due to the absence of effective energy recovery mechanisms. A specific challenge arises when managing energy recuperated during regenerative braking, which is typically lost if not immediately reused. This study proposes the integration of on-board energy storage systems (ESS) based on supercapacitor technology to temporarily store excess braking energy. A mathematical model of a traction drive with a DC motor and supercapacitor-based ESS is developed, accounting for variable load profiles and typical urban driving cycles. Simulation results demonstrate potential energy savings of up to 30%, validating the feasibility of the proposed solution. The model also enables system-level analysis for optimal ESS sizing and placement in electric rail vehicles. Full article

Despite its higher density, viscosity, and lower calorific value, biodiesel has been explored as an alternative energy source to diesel fuel. This study investigated biodiesel produced from croton macrostachyus (CMS) seed, a non-edible feedstock. The research aimed to experimentally analyze cylinder pressure, heat release rate, and ignition delay, as well as engine performance and emission characteristics, at a constant speed of 2700 rpm under varying loads (0–80%) using diesel, B10, B15, B20, and B25 blended fuels. Among the tested blends, B25 exhibited superior performance, achieving the highest peak cylinder pressure (CP) of 58.21 bar and a maximum heat release rate (HRR) of 543.9 J/CA at 80% engine load. Conversely, B20 at 60% engine load, followed by B25 and pure diesel at 80% engine load, demonstrated the shortest ignition delay (ID) and the most advanced start of combustion (SoC). Compared to the biodiesel blends, pure diesel showed: a 5.5–14% increase in brake thermal efficiency (BTE), a 17–26% decrease in brake-specific fuel consumption (BSFC), and a 7–12% reduction in exhaust gas temperature (EGT). Regarding emissions, carbon monoxide (CO) and hydrocarbon (HC) emissions were lower for pure diesel, while carbon dioxide (CO₂) and nitrogen oxide (NOx) emissions were higher for biodiesel blends, attributed to their inherent oxygen content. In conclusion, CMS biodiesel displays promising characteristics, suggesting its potential suitability for use in internal combustion engines. Full article

This study examined the effects of blending decanol, an oxygenated fuel, with diesel on diesel engine performance and emissions. Experiments were conducted on a single-cylinder engine at 1700 rpm and 2700 rpm, using diesel/decanol blends at 10%, 30%, and 50% by volume (D90de10, D70de30, D50de50). Results showed that brake thermal efficiency decreased with higher decanol ratios at low speeds. As a result, brake specific fuel consumption and brake specific energy consumption increased due to decanol’s lower calorific value. Regarding emissions, decanol blending reduced NO_x, CO, HC, and smoke. NO_x emissions were lowered by the cooling effect resulting from decanol’s higher latent heat of vaporization and lower calorific value, especially at low speeds. CO and HC emissions declined as decanol’s oxygen content promoted oxidation, reducing incomplete combustion. Smoke emissions were minimized in fuel-rich zones by preventing unburned carbon particle formation. This study highlights decanol’s potential as an eco-friendly diesel blending option. Future work should optimize blending ratios and injection settings to enhance diesel engine performance. Full article

Increasing the use of renewable biofuels in internal-combustion-engine (ICE) vehicles is a key strategy for reducing greenhouse gas emissions and conserving fossil fuels. Hybrid vehicles used in urban environments significantly reduce fuel consumption compared to conventional internal-combustion-engine cars. In hybrid vehicles integrating electric propulsion with biofuels offers even more significant potential to lower fuel consumption. One would like to think they should also be less polluted in all cases, but some results show that the opposite is true. This study’s aim was to evaluate a hybrid vehicle’s energy and environmental performance using different gasoline–bioethanol blends. A Worldwide Harmonized Light Vehicles Test Cycle (WLTC) study was conducted on a Toyota Prius II hybrid vehicle to assess changes in energy and environmental performance. During the WLTC test, data were collected from the chassis dynamometer, exhaust gas analyser, fuel consumption meter, and engine control unit (ECU). The collected data were synchronised, and calculations were performed to determine the ICE cycle work, brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), pollutant emissions (CO, HC, and NO_x), CO₂ mass emissions per cycle, and brake specific pollutant emissions per kilometre. The study shows that the performance of the hybrid vehicle’s ICE is strongly influenced by the utilisation of electrical energy stored in the battery, especially at low and medium speeds. As the bioethanol concentration increases, the engine’s ECU advances the ignition timing based on the knock sensor signal. A comprehensive evaluation using the WLTC indicates that increasing the bioethanol concentration up to 70% improves the energy efficiency of the hybrid vehicle’s internal combustion engine and reduces pollutant and CO₂ emissions. Full article

As the need for alternative energy sources and reduced emissions grows, proven technologies are often sidelined in favour of emerging solutions that lack the infrastructure for mass adoption. This study explores a transitional approach by modifying existing compression ignition engines to run on a hydrogen/diesel mixture for performance improvement, utilising water injection to mitigate the drawbacks associated with hydrogen combustion. This approach can yield favourable results with current technology. In this modelling study, ten hydrogen energy ratios (0–90%) and nine water injection rates (0–700 mg/cycle) were tested in a turbocharged Cummins ISBe 220 31 six-cylinder diesel engine. An engine experiment was conducted to validate the model. Key performance indicators such as power, mechanical efficiency, thermal efficiency, indicated mean effective pressure (IMEP), and brake-specific fuel consumption (BSFC) were measured. Both water injection and hydrogen injection led to slight improvements in all performance metrics, except BSFC, due to hydrogen’s lower energy density. In terms of emissions, CO and CO₂ levels significantly decreased as hydrogen content increased, with reductions of 94% and 96%, respectively, at 90% hydrogen compared to the baseline diesel. Water injection at peak rates further reduced CO emissions by approximately 40%, though it had minimal effect on CO₂. As expected, NOx (which is a typical challenge with hydrogen combustion and also with diesel engines in general) increased with hydrogen fuelling, resulting in an approximately 70% increase in total NOx emissions over the range of 0–90% hydrogen energy. Similar increases were observed in NO and NO₂, e.g., 90% and 57% increases with 90% hydrogen, respectively. However, water injection reduced NO and NO₂ levels by up to 16% and 83%, respectively, resulting in a net decrease in NO_X emissions in many combined cases, not only with hydrogen injection but also when compared to baseline diesel. Full article

Ecuador’s Energy Efficiency Law mandates that “as of 2030, all vehicles incorporated into urban public transport services must be electric”. This legal framework sets the stage for the country’s transition to electric mobility. This research examines the energy requirements for transitioning Ambato’s public bus fleet to electric vehicles, considering various technical and operational factors. The analysis evaluates the current fleet size, the expected lifespan of buses, daily operational hours, average speed, and the specific characteristics of the city’s public transport routes. Furthermore, this study delves into the technical aspects of energy consumption in electric public transport by calculating the driving force necessary to operate buses across different terrains and routes. Factors such as bus weight, passenger load, road gradient, and acceleration patterns are analyzed to assess their impact on energy consumption and vehicle range. Additionally, this study investigates the potential for regenerative braking and the necessary charging infrastructure, offering a comprehensive assessment of how these systems would function within Ambato. By forecasting future vehicle requirements and projecting growth in urban mobility, this study estimates the total energy demand for a fully electric public bus fleet. The potential for integrating renewable energy sources into the city’s grid is also explored, ensuring that the transition to electric mobility not only decreases reliance on fossil fuels but also supports cleaner energy sources. This research serves as a crucial step in understanding the infrastructure and policy changes required for the successful implementation of electric public transport in Ambato and similar Ecuadorian cities. Full article

Biodiesel is a promising alternative fuel that represents a sustainable and environmentally friendly energy source. Due to its complete carbon cycle, it reduces dependence on fossil fuels and lowers greenhouse gas emissions. However, the use of biodiesel in diesel engines is associated with several challenges, including an increase in nitrogen oxide and particulate emissions, incompatibility with cold climates, and lower calorific value. By using nanoparticles as fuel additives, there is a potential to improve the properties of biodiesel and address its shortcomings. In this work, the characteristics of biodiesel derived from waste cooking oil have been enhanced using nanoparticle additives, which result in the usage of a higher percentage of the biodiesel in diesel engines. Nanoparticles of cerium oxide, silicon dioxide, and aluminum oxide have been investigated in different concentrations as biodiesel additives. Two mathematical models are introduced in this work and solved by LINGO optimization software (version 18); the first one seeks to predict the characteristics of biodiesel with nanoparticles in any blend of diesel–biodiesel–nanoparticles, while the second model aims to maximize the biodiesel ratio in a biodiesel–diesel–nanoparticles blend. The application of the combined two models aids in the selection of the optimal nanomaterial that improves the properties of biodiesel and permits an increase in the biodiesel mixing ratio in the fuel. The results show that the best nanoparticle type is cerium oxide at a concentration of 100 ppm, and the optimal mixing ratio of biodiesel blended with CeO₂ nanoparticles is 24.892%. An unmodified diesel engine is operated and evaluated with the optimum blend (24.892% biodiesel + 75.108% petrol diesel + 100 ppm CeO₂ nanoparticles). It is found that significant improvements in engine performance and emissions compared with the conventional diesel are achieved. The reductions in brake-specific fuel consumption (BSFC), smoke opacity, and carbon monoxide emissions are 24%, 52%, and 30%, respectively. Full article

In a world with severe pollution regulations and restrictions imposed to internal combustion engines, improving efficiency and reducing pollutant emissions and greenhouse gases are important goals for researchers. A highly effective method to achieve the premises written above is to use alternative fuels, which may have a strong influence on combustion processes in spark ignition engines. In order to increase the heat release rate during combustion, the brake thermal efficiency, and to decrease the levels of pollutant emissions and greenhouse gases, the use of sustainable alternative fuels, in parallel with conventional fuels is a great choice. Among alternative fuels, hydrogen is an excellent fuel in terms of its physical-chemical properties, making it an attractive replacement for classic fuels in the combustion process. This article demonstrates AMESim 13.0.0/Rev13 theoretical and experimental investigations conducted on a supercharged spark ignition engine at 55% engine load and 2500 rpm speed, analyzes the effect of 2.15% hydrogen that substitutes gasoline on combustion, implicitly investigates energy and fuel efficiency of the engine and investigates pollutant and greenhouse gas emission levels. These experimental investigations confirm the theoretical study of thermo-gas-dynamic processes of a SI engine fueled with gasoline and hydrogen, and it shows the importance of engine tunings and hydrogen quantity on engine operation. The obtained results indicate the advantages of fueling the engine with both gasoline and hydrogen: the increase of the heat release rate which leads to the increase of maximum pressure and maximum pressure rise rate during combustion, the increase of the brake thermal efficiency, the decrease of the combustion duration, the decrease of the brake specific energetic consumption by 4.8%, the decrease of the levels of pollutant emissions by 11.11% for unburned hydrocarbons HC, by 12.5% for monoxide carbon CO, by 63.23% for nitrogen oxides NO_x, and by 33.7% for carbon dioxide CO₂ as a greenhouse gas. Further research directions can be developed from this research for other operating regimes and other hydrogen quantities. Full article

Fuelled engines serve as prime movers in low-, medium-, and heavy-duty applications with high thermal diesel efficiency and good fuel economy compared to their counterpart, spark ignition engines. In recent years, diesel engines have undergone a multitude of developments, however, diesel engines release high levels of NOx, smoke, carbon monoxide [CO], and hydrocarbon [HC] emissions. Due to the exponential growth in fleet population, there is a severe burden caused by petroleum-derived fuels. To tackle both fuel and pollution issues, the research community has developed strategies to use economically viable alternative fuels. The present experimental investigations deal with the use of blends of biodiesel prepared from waste plastic oil [P] and petro-diesel [D], and, to improve its performance, hydrogen [H] is added in small amounts. Further, advanced injection timings have been adopted [17.5° to 25.5° b TDC (before top dead centre)] to study their effect on harmful emissions. Hydrogen energy shares vary from 5 to 15%, maintaining a biodiesel proportion of 20%, and the remaining is petro-diesel. Thus, the adopted blends are DP20 ((diesel fuel (80%) and waste plastic biofuel (20%)), DP20H5 (DP20 (95%) and hydrogen (5%)), DP20H10 (DP20 (90%) and hydrogen (10%)), and DP20H15 (DP20 (85%) and hydrogen (15%)). The experiments were conducted at constant speeds with a rated injection pressure of 220 bar and a rated compression ratio of 18. The increase in the share of hydrogen led to a considerable improvement in the performance. Under full load conditions, with advanced injection timings, the brake-specific fuel consumption had significantly decreased and NOx emissions increased. Full article

In response to the EU’s stringent zero-carbon emission standards for 2035 and global initiatives to phase out fossil-fuel-powered vehicles, there is an urgent need for innovative solutions in vehicle propulsion systems. While much of the current research focuses on electric passenger cars, commercial vehicles remain relatively underexplored despite their significant potential impact on carbon neutrality goals. This study presents an open-source Simulink model specifically tailored for the analysis of electric commercial trucks, concentrating on the 6.5-ton category. Developed to assess the influence of various power components and control strategies on driving range, the model incorporates three validated powertrain configurations and features such as regenerative braking and one-pedal drive. Simulations are conducted under two real-world driving scenarios in the city of Taipei in Taiwan to evaluate different configurations’ effects on energy consumption and efficiency. Results indicate that optimizing the vehicle configuration can reduce power consumption by 26.3% and extend driving range by an additional 25.1 km on a single battery charge. By making the model and its source code publicly available, this research not only fills a critical gap in specialized evaluation tools for electric commercial vehicles but also serves as a valuable resource for both industrial assessments and educational purposes in the field of vehicle electrification. Full article

This study evaluates the viability of n-octanol as an alternative fuel in a direct-injection diesel engine, aiming to enhance sustainability and efficiency. Experiments fueled by different blends of n-octanol with pure diesel were conducted to analyze their impacts on engine performance and emissions. The methodology involved testing each blend in a single-cylinder engine, measuring engine performance parameters such as brake torque and brake power under full-load conditions across a range of engine speeds. Comparative assessments of performance and emission characteristics at a constant engine speed were also conducted with varying loads. The results indicated that while n-octanol blends consistently improved brake thermal efficiency, they also increased brake-specific fuel consumption due to the lower energy content of n-octanol. Consequently, while all n-octanol blends reduced nitrogen oxide emissions compared to pure diesel, they also significantly decreased carbon monoxide, hydrocarbons, and smoke opacity, presenting a comprehensive reduction in harmful emissions. However, the benefits came with complex trade-offs: notably, higher concentrations of n-octanol led to a relative increase in nitrogen oxide emissions as the n-octanol ratio increased. The study concludes that n-octanol significantly improves engine efficiency and reduces diesel dependence, but optimizing the blend ratio is crucial to balance performance improvements with comprehensive emission reductions. Full article

The blending of biodiesel with petroleum diesel attracts much attention due to its high potential in reducing emissions. In this work, waste sunflower oil was converted to biodiesel by the trans-esterification method, and it was blended with petroleum diesel in three ratios (10, 30, and 50%). The impact of using these blended fuels in a four-stroke engine on engine performance and exhaust emissions at three engine loads (2, 4, and 6 N.m) was investigated and compared with the use of petroleum diesel and biodiesel. The engine performance was evaluated by determining the brake-specific fuel consumption (BSFC), engine effective power (Ne), brake-specific energy consumption (BSEC), brake thermal efficiency (BTE), and noise intensity. The evaluation of emissions from the engine exhaust was carried out by measuring the levels of carbon oxides (CO and CO₂), hydrocarbons (HC), nitrogen oxides (NO and NO₂), and particulate matter (PM). The results show that blending diesel with up to 30% biodiesel can reduce CO, HC, and PM emissions by 29.6 ± 1%, 26.0 ± 4%, and 31.0 ± 3%, respectively. However, this decrease is associated with increasing CO₂ and NOx emissions by 18.5 ± 2.5% and 29.0 ± 6%, respectively. In addition, the engine showed acceptable performance when using up to 30% biodiesel, where the increase in fuel consumption was limited to 5.8 ± 0.3%. In addition, the engine’s effective power increased with the blending ratio of 10% by 2.0 ± 0.6%, but then decreased with the blending ratio of 30% by only 2.0 ± 0.6%. The noise intensity was also decreased by 2.4%, while BSEC and BTE were reduced by only 2.9 ± 0.9% and 3.5 ± 1%, respectively. The results of this work provide deep insights regarding the utilization of waste sunflower oil as biodiesel to be blended with petroleum diesel, which is a considerable novel approach in the energy and environmental sectors. Full article

This study investigates the performance of a 4-MIX engine utilizing hydrogen combustion in pure oxygen, water injection, and the application of the early-intake valve closure (EIVC) Miller cycle. Transitioning from a standard petrol–oil mix to hydrogen fuel with pure oxygen combustion aims to reduce emissions. Performance comparisons between baseline and oxyhydrogen engines showed proportional growth in the energy input rate with increasing rotational speed. The oxyhydrogen engine exhibited smoother reductions in brake torque and thermal efficiency as rotational speed increased compared to the baseline, attributed to hydrogen’s higher heating value. Water injection targeted cylinder and exhaust temperature reduction while maintaining a consistent injected mass. The results indicated a threshold of around 2.5 kg/h for the optimal water injection rate, beyond which positive effects on engine performance emerged. Investigation into the EIVC Miller cycle revealed improvements in brake torque, thermal efficiency, and brake specific fuel consumption as early-intake valve closure increased. Overall, the EIVC model exhibited superior energy efficiency, torque output, and thermal efficiency compared to alternative models, effectively addressing emissions and cylinder temperature concerns. Full article

When a medium–low-speed (MLS) maglev train is braking, part of its regenerative braking (RB) power consumption may cause a significant rise in the positive rail (PR) voltage. For RB energy re-utilization, an RB energy feedback system (RBEFS) is a promising application, but there is still no specific research in the field of MLS maglev trains. From this perspective, this article focuses on identifying the PR voltage rise behavior and investigating the application of an RBEFS on the over-voltage inhibition. Some development trends of the MLS maglev train, including the DC 3 kV traction grid system and the speed being raised to 160~200 km/h, are also considered in the analyzed scenarios. At first, a modeling scheme of a detailed vehicle–grid electrical power model with the RBEFS is established. On this basis, the PR voltage rise characteristics are analyzed with consideration of three pivotal influencing factors: RB power, PR impedance and supply voltage level. Subsequently, to stabilize the PR voltage fluctuations, the influence rules of the RBEFS on the voltage rise and the mutual transient voltage influences under the operating status switching for multiple vehicles running on the same power supply section are analyzed. Full article

It is important to reduce the negative environmental effects of non-road diesel engines, which are increasingly used in many facilities and machines, without loss of performance. Biodiesel is used as an alternative to fossil-based diesel fuels to eliminate these effects and ensure sustainability in energy. This study focused on the optimization of the operating parameters of a non-road diesel engine operating with a waste frying oil biodiesel mixture at 50% load. Pure biodiesel, 1-heptanol, different injection advances and pressures were determined as input parameters for optimization. The tests were designed according to Taguchi’s L16 orthogonal array. ANOVA analysis was performed to determine the importance of input parameters on engine performance and exhaust emissions. Optimization was made based on the highest brake thermal efficiency (BTE) in addition to the lowest values of brake-specific fuel consumption (BSFC), brake-specific hydrocarbon (BSHC), brake-specific nitrogen oxide (BSNOx) and smoke emissions. In the optimization carried out according to the response surface methodology (RSM), the optimum combinations to obtain the best engine characteristics were determined as 17.27% 1-heptanol, a 226-bar injection pressure, 27 CAD injection advance and B75. These optimization results were verified by engine experiments within the recommended error range. Full article