Search Results (79)

Based on engine bench testing, this study investigated the effect of diesel oxidation catalytic converter (DOC) formulations on the gaseous emissions performance of diesel engines equipped with a DOC+ catalyzed diesel particulate filter (CDPF)+selective catalytic reduction (SCR) system after the treatment system. The experimental results indicate that changes in DOC formulations have no significant effect on engine fuel economy. As the precious metal loading increases and the Pt/Pd ratio decreases, the T₅₀ for CO and HC decreases, and the low-temperature conversion rates (<300 °C) for CO and HC increase. However, as the temperature continues to rise, the beneficial effect of increased precious metal loading or Pd on CO and HC conversion rates gradually weakens. The average conversion rates in the high-temperature range (≥300 °C) show little difference. The NO conversion rate increases with increasing precious metal loading. The NO conversion rate is more sensitive to Pt content, with higher Pt content formulations promoting NO oxidation, contrary to the trends observed for CO and HC conversion rates. When the SCR inlet temperature is low, high NO₂ concentrations are beneficial for improving the SCR’s NOx conversion efficiency. When the SCR inlet temperature is high, the SCR’s NOx conversion efficiency exceeds 90% with no significant differences. No significant impact of DOC formulation changes on CDPF pressure drop under external conditions was observed. Full article

The presented research examined the impact of using biodiesel as a fuel for existing diesel engines during the transition to the broader adoption of electric vehicles powered by renewable energy or through integrated hybrid drive systems. The authors considered previous research on this topic, which is demonstrated by a literature review. This paper will utilize the findings to further explore the potential of optimizing existing engines by using biodiesel and thus propose their continued use in the transition period as one of the clean fuels. This paper outlines the standards that define fuel quality and presents a test bench equipped with an experimental engine and specialized equipment for laboratory examination, enabling the measurement of emissions and the determination of cylinder pressure. To ensure the repeatability of the experimental conditions and facilitate future comparison of the obtained results, the engine examination was conducted according to the standard ESC 13-mode test. The examination process confirmed a significant reduction in particulate matter emissions (on average 40%) but, simultaneously, an increase in nitrogen oxide emissions (on average 25%), whose level, according to data from the literature, depends on the type of raw materials used for biodiesel production. Brake thermal efficiency is higher when operating with biodiesel (on average 1.5%). Still, it was concluded that the use of biodiesel in existing diesel engines is feasible only if the engines are equipped with variable systems for automatically adjusting the compression ratio, fuel injection time, valve timing, and so on. The outcomes from the examination conducted can be further processed by applying statistical methods and represent an essential database for further research in this scientific area. Full article

This paper presents the results of naturally aspirated compression ignition (CI) internal combustion engine (ICE) bench tests of fuels in the form of a blend of diesel oil with recycled oil (RF) in the form of tire pyrolysis oil (TPO) as an admixture with the content of pyrolytic oil with the blend being 10% m/m (D90+RF10). The results relate to reference conditions in which the engine is fed with pure diesel oil (D100). The experiment included the evaluation of engine performance and the determination of the content of selected substances in the exhaust gas for brake-set engine loads equal to 5 Nm, 10 Nm, 15 Nm, and 20 Nm. For each load, engine operating parameters and emissions of selected exhaust components were recorded at preset speeds in the range of 1400–2400 rpm for each engine load. The hourly fuel consumption and exhaust gas temperature were determined. The contents of CO₂, CO, and HC in the exhaust gas were measured. The consumption of D90+RF10 increased by 56%, and CO₂ emissions were 21.7% higher at low loads. The addition of sulfur-containing pyrolytic oil as an admixture to diesel oil resulted in SO_x emissions. The results show the suitability of pyrolytic oil and the possibility of using it as an admixture to fossil fuels. In order to meet SO_x emission levels in land-based installations and for vehicle propulsion, it is necessary to desulfurize fuel or desulfurize deSO_x exhaust gas systems. The CO and HC emission levels in the exhaust gases from the engine powered by the D90+RF10 fuel meet current requirements for motor vehicle exhaust composition. Full article

As a major emission pollutant from diesel engines, NOx is extremely harmful to the environment and human health. In order to reduce NOx emissions, countries around the world have been implementing increasingly stringent emissions regulations. The urea injection strategies of the Selective Catalytic Reduction (SCR) system are the main factors affecting NOx emissions and NH₃ slips of diesel engines. In this study, test data were obtained from an engine test stand and a Support Vector Machine (SVM) was developed using the test data to predict NOx conversion efficiency and NH₃ slip. The SVM model was optimized using the Crested Porcupine Optimizer (CPO) to improve its prediction accuracy and was made to replace the mathematical model to save computational time. Finally, the Nondominated Sorting Genetic Algorithm II (NSGA-II) was used to optimize the urea injection volume for all conditions. The optimized urea injection volume maximizes the NOx conversion efficiency of the SCR system while controlling the NH₃ slip within 10 ppm. In addition, based on this method, the urea injection pulse spectrum under full operating conditions was obtained, and the optimized urea injection amount can effectively reduce the NOx accumulation of the WHTC cycle by about 7.5%, as shown through bench testing. Full article

Compressed natural gas (CNG) in dual-fuel diesel engines offers environmental benefits but significantly increases unburned methane (CH₄) emissions, especially at low engine loads. This study investigates the effectiveness of different catalytic converters in methane oxidation under transient test conditions (WHTC). Three types of catalysts (Pt-, Rh-, and Pd-based) were evaluated using a combined approach of empirical engine bench tests and mathematical modelling. The results showed that, under actual exhaust gas temperature conditions, the average methane conversion efficiencies were 3.7% for Pt, 17.7% for Rh, and 31.3% for Pd catalysts. Increasing the exhaust gas temperature by 50% improved the conversion efficiencies to 7.3%, 51.8%, and 69.2%, respectively. Despite this enhancement, none of the catalysts reached the 90% efficiency threshold required to increase the CNG content of the fuel beyond 6% without exceeding emission limits. The results highlight the need for high-activity Pd-based catalysts and optimised thermal management strategies to enable the broader adoption of dual-fuel engines, while complying with Euro VI standards. Full article

With the continuous development of industrial automation, diesel engines play an increasingly important role in various types of construction machinery and power generation equipment. Improving the dynamic and static performance of the speed control system of single-cylinder diesel engines can not only significantly improve the efficiency of the equipment, but also effectively reduce energy consumption and emissions. Particle swarm optimization (PSO) fuzzy PID control algorithms have been widely used in many complex engineering problems due to their powerful global optimization capability and excellent adaptability. Currently, PSO-based fuzzy PID control research mainly integrates hybrid algorithmic strategies to avoid the local optimum problem, and lacks optimization of the dynamic noise suppression of the input error and the rate of change of the error. This makes the algorithm susceptible to the coupling of the system uncertainty and measurement disturbances during the parameter optimization process, leading to performance degradation. For this reason, this study proposes a new framework based on the synergistic optimization of the untraceable Kalman filter (UKF) and PSO fuzzy PID control for the speed control system of a single-cylinder diesel engine. A PSO-optimized fuzzy PID controller is designed by obtaining accurate speed estimation data using the UKF. The PSO is capable of quickly adjusting the fuzzy PID parameters so as to effectively alleviate the nonlinearity and uncertainty problems during the operation of diesel engines. By establishing a Matlab/Simulink simulation model, the diesel engine speed step response experiments (i.e., startup experiments) and load mutation experiments were carried out, and the measurement noise and process noise were imposed. The simulation results show that the optimized diesel engine speed control system is able to reduce the overshoot by 76%, shorten the regulation time by 58%, and improve the noise reduction by 25% compared with the conventional PID control. Compared with the PSO fuzzy PID control algorithm without UKF noise reduction, the optimized scheme reduces the overshoot by 20%, shortens the regulation time by 48%, and improves the noise reduction effect by 23%. The results show that the PSO fuzzy PID control method with integrated UKF has superior control performance in terms of system stability and accuracy. The algorithm significantly improves the responsiveness and stability of diesel engine speed, achieves better control effect in the optimization of diesel engine speed control, and provides a useful reference for the optimization of other diesel engine control systems. In addition, this study establishes the GT-POWER model of a 168 F single-cylinder diesel engine, and compares the cylinder pressure and fuel consumption under four operating conditions through bench tests to ensure the physical reasonableness of the kinetic input parameters and avoid algorithmic optimization on the distorted front-end model. Full article

Diesel vehicles are recognized as significant mobile sources of particulate matter emissions. As a renewable and environmentally friendly alternative to conventional fossil diesel, biodiesel offers the benefit of reducing greenhouse gas emissions. However, existing research on biodiesel emissions primarily focuses on primary emissions, with a limited understanding of their impact on secondary organic aerosol (SOA) formation. In this study, a diesel engine test bench was employed under idle conditions using three commonly used biodiesel blends. Exhaust emissions were directly introduced into the HAP-SWFU chamber, a quartz glass smog chamber designed to characterize both primary emissions and SOA formation during the photochemical oxidation process. The black carbon and primary organic aerosol (POA) emission factors for the three biodiesel blends under idle conditions ranged from 0.31 to 0.58 g kg⁻¹ fuel and 0.99 to 1.06 g kg⁻¹ fuel, respectively. The particle size of exhaust particulates peaked between 20 and 30 nm, and nucleation-idle conditions were found to be the dominating mode. The SOA production factor was between 0.92 and 1.15 g kg⁻¹ fuel, and the SOA/POA ratio ranged from 1.35 to 2.37, with an average of 1.86. This study concludes that the POA emission factor for biodiesel under idle conditions is comparable to values reported in previous studies on pure diesel exhaust, with the maximum SOA production factor reduced by 38%. Full article

Shipping, as the most efficient, cheapest, and most widespread mode of transporting goods, also generates significant exhaust emissions. This has led to the adoption of stringent regulatory restrictions on emissions from ship propulsion systems. Consequently, the education and training of marine engineers can significantly impact their understanding of how emissions are generated and their potential for reduction. The engine room simulator is an indispensable tool in the training of marine engineers. Since operating conditions and parameters have the greatest impact on NOx emissions, this forms the primary focus of this research. This study tests the accuracy and precision of the engine room simulator in simulating emissions and evaluating the influence of operating conditions on them. Furthermore, the implementation and testing of NOx emission reduction technologies are vital for promoting sustainable shipping, ensuring regulatory compliance, and training personnel to support environmentally conscious maritime operations. Using the example of a two-stroke marine diesel engine, the results obtained are compared with test bench data from similar engines. Special emphasis is placed on simulating the operation of a two-stroke diesel engine at low speed, or low load, where secondary NOx reduction methods cannot be used. Therefore, the simulator is tested using two available technologies: water–fuel emulsion and altering the fuel injection timing to reduce NOx emissions. The simulation results for the water–fuel emulsion show high accuracy in predicting NOx emission trends when changing the water content in the emulsion at nominal power. However, at low load, the results show significant deviations. Testing the effect of altering fuel injection timing under low load using the engine room simulator shows significant differences compared to available research. Nonetheless, research on NOx emissions in this engine mode is limited, presenting a potential area for further study. When comparing the results for nominal power operation, the simulation provides more accurate results, particularly in terms of the influence of fuel injection timing on NOx emissions. However, engine tests on the test bench still reveal more substantial changes in emissions than those obtained using the engine room simulator. Full article

This paper presents the design and development of a proof of concept (PoC) open-source data logger system for wireless data acquisition via Wi-Fi aimed at bench testing and fault detection in combustion and electric engines. The system integrates multiple sensors, including accelerometers, microphones, thermocouples, and gas sensors, to monitor critical parameters, such as vibration, sound, temperature, and CO₂ levels. These measurements are crucial for detecting anomalies in engine performance, such as ignition and combustion faults. For combustion engines, temperature sensors detect operational anomalies, including diesel engines operating beyond the normal range of 80 °C to 95 °C and gasoline engines between 90 °C and 110 °C. These readings help identify failures in cooling systems, thermostat valves, or potential coolant leaks. Acoustic sensors identify abnormal noises indicative of issues such as belt misalignment, valve knocking, timing irregularities, or loose parts. Vibration sensors detect displacement issues caused by engine mount failures, cracks in the engine block, or defects in pistons and valves. These sensors can work synergistically with acoustic sensors to enhance fault detection. Additionally, CO₂ and organic compound sensors monitor fuel combustion efficiency and detect failures in the exhaust system. For electric motors, temperature sensors help identify anomalies, such as overloads, bearing problems, or excessive shaft load. Acoustic sensors diagnose coil issues, phase imbalances, bearing defects, and faults in chain or belt systems. Vibration sensors detect shaft and bearing problems, inadequate motor mounting, or overload conditions. The collected data are processed and analyzed to improve engine performance, contributing to reduced greenhouse gas (GHG) emissions and enhanced energy efficiency. This PoC system leverages open-source technology to provide a cost-effective and versatile solution for both research and practical applications. Initial laboratory tests validate its feasibility for real-time data acquisition and highlight its potential for creating datasets to support advanced diagnostic algorithms. Future work will focus on enhancing telemetry capabilities, improving Wi-Fi and cloud integration, and developing machine learning-based diagnostic methodologies for combustion and electric engines. Full article

Straight soybean and diesel oil blends are proposed as alternatives for electricity generation in isolated regions. The compression ignition engine is considered the prime mover and has the attractive potential to distribute electricity generation for supply in isolated regions, as well as for small applications demanded by the agro-industrial sector. The heat release rate evaluation of straight soybean blends is the main focus of this paper. A single-cylinder compression ignition engine with a nominal power of 14.7 kW/2200 rpm fueled with blends of 50% and 80% v/v straight soybean oil with commercial diesel oil was tested on a dynamometer bench. The heat release rate and ignition delay were determined from in-cylinder pressure measurements using zero-dimensional modeling. The experimental results showed a promising performance and coherent behavior with the physicochemical fuel properties and load conditions tested. The highest fraction of vegetable oil led to a combustion delay, characterized by high diffusive and residual combustion phases, although the fuel oxygen content favored the combustion. Finally, this work allowed observation of the development of the heat release rate of straight soybean blends in a diesel engine, understanding the influence of the fuel properties and in-cylinder gas properties on the combustion process. Full article

Diesel engines are popular due to their efficiency, power, and fewer carbon emission features. But NOx emissions pose a significant challenge to diesel engines’ use. NOx emissions are the largest constituents of diesel engines’ exhaust pollutants, with proven adverse effects on environment and human health. Different emission control strategies have been in use to inhibit NOx emission in diesel engines and to satisfy the global environmental standards. Port water injection, a relatively new emission control technology offers a solution to effectively inhibit the NOx emissions without significantly changing the standard combustion mode of diesel engines. This study experimentally investigates the impact of port water addition on air–fuel ratios (lambda ratios) and NOx emissions in a high-speed diesel engine. This investigation is carried out through experimentation on the diesel engine connected on a test bench across four operating conditions representing one low, one medium, and two high loading conditions. The experimentation introduced multiple port water injection rates from 0 to 21 kg/h. Results showed a 3–8% reduction in the lambda ratio and a substantial 75–89% decrease in NOx emissions with water addition. Importantly, combustion remained in the standard lean mode, affirming the effectiveness of port water injection in curbing NOx emissions while maintaining the required air–fuel ratio (lambda ratio). Full article

Diesel pallet trucks, a type of heavy-duty diesel trucks (HDDTs), have historically been a vital component in logistics and transport due to their high payload capacity. However, they also present significant challenges, particularly in terms of emissions which contribute substantially to urban air pollution. Traditional HDDTs emission measurement methods, such as engine bench tests and those used in laboratory settings, often fail to capture real-world emission behaviors accurately. This study specifically examines the real-world emission characteristics of diesel pallet trucks exceeding 30 t under varying loads (unloaded, half loaded, and fully loaded) and different road conditions (urban, suburban, and high-speed). Considering that data quality is the key to the accuracy of the scheme, this research utilized a portable emission measurement system (PEMS) to capture real-time emissions data of carbon dioxide (CO₂), carbon monoxide (CO), nitrogen oxides (NO_X), and total hydrocarbons (THC). Key findings demonstrate a direct correlation between vehicle load and emission factors, with the emission factors for CO₂, CO, and NO_X increasing by 39.5%, 105.4%, and 22.7%, respectively, from unloaded to fully loaded states under comprehensive operating conditions. Regression analyses further provide an emission factor prediction model for HDDPTs, underscoring the continuous relationship between speed, load, and emission rates. These findings provide a scientific basis for pollution control strategies for diesel trucks. Full article

This research aims to delve into the intricacies of combustion processes, specifically focusing on heating oil and a blend of heating oil with Tire Pyrolysis Oil (TPO) in a self-developed evaporative combustion chamber featuring steam injection. The primary objective is to scrutinize the impact of steam injection on the combustion dynamics. Conducting a series of tests, the investigation involved the meticulous manipulation of stoichiometric ratios while introducing ambient air through gravity fuel flow. Subsequent iterations of these tests incorporated the introduction of steam into the ambient air stream. The examination encompassed the combustion of both heating oil and the TPO blend within the combustion chamber. The evaluation criteria comprised an in-depth analysis of flame characteristics, temperature distribution within the combustion chamber, and the quantification of emissions such as particulate matter (PM), nitrogen oxides (NO_x), carbon dioxide (CO₂), carbon monoxide (CO), and water vapor (H₂O). Throughout the experimentation phase, commercially available diesel fuel served as the primary fuel source. To facilitate the tests, the combustion chamber under scrutiny was seamlessly integrated into an AVL engine test bench system. Essential parameters, including fuel consumption, were meticulously gauged using an AVL 735 fuel flow meter, while fuel temperature was monitored using the AVL 745 fuel temperature conditioning system. The intake air, a crucial element in the combustion process, was quantified with precision using an AVL Flowsonix sensor. Emission measurements were conducted meticulously using state-of-the-art equipment, with gaseous emissions analyzed using an AVL FTIR AMA i60 exhaust gas analyzer. Simultaneously, soot emissions were quantified through employment of an AVL Micro Soot sensor. This comprehensive approach not only delves into the fundamental aspects of combustion but also extends its reach to the exploration of innovative techniques, such as steam injection, to enhance combustion efficiency and reduce emissions. The integration of advanced measurement tools ensures a robust and thorough analysis of the combustion process and its environmental implications. Full article

The present research analyses the injection rate of a direct rail injection diesel engine, focusing specifically on the influence of the nozzles and various operating conditions from real road tests on the rate of injection. A diesel injector test bench was used for feedback with real data from the test vehicle under real road conditions. An analysis of the behaviour of the injection rate was carried out using the zero-dimensional model. This model generated a predictive model that incorporated the five variables identified through a developed multivariate analysis of variance, showing a high correlation of dependence between variations in injection pressure, the diameter of the holes, and the number of holes with greater representativeness. The results obtained showed that the nozzle geometry and the physical properties of the fuel had a direct effect on the injection rate. This analysis enriches the understanding of fuel injection and its effects on diesel engine performance by providing an analysis of the system components that influence the injection rate and generating a simple tool to feed thermodynamic diagnostic models. The proposal model may be used as an input in thermodynamics predictive models and reduce the simulation load in computational fluid dynamics predictive models. Full article

Regardless of the increasingly intensive application of vehicles with electric drives, internal combustion engines are still dominant as power units of mobile systems in various sectors of the economy. In order to reduce the emission of exhaust gases and satisfy legal regulations, as a temporary solution, hybrid drives with optimized internal combustion engines and their associated systems are increasingly being used. Application of the variable compression ratio and diesel fuel injection timing, as well as the tribological optimization of parts, contribute to the reduction in fuel consumption, partly due to the reduction in mechanical losses, which, according to test results, also results in the reduction in emissions. This manuscript presents the results of diesel engine testing on a test bench in laboratory conditions at different operating modes (compression ratio, fuel injection timing, engine speed, and load), which were processed using a zero-dimensional model of the combustion process. The test results should contribute to the optimization of the combustion process from the aspect of minimal particulate matter emission. As a special contribution, the results of tribological tests of materials for strengthening the sliding surface of the aluminum alloy piston and cylinder of the internal combustion engine and air compressors, which were obtained using a tribometer, are presented. In this way, tribological optimization should also contribute to the reduction in particulate matter emissions due to the reduction in fuel consumption, and thus emissions due to the reduction in friction, as well as the recorded reduction in the wear of materials that are in sliding contact. In this way, it contributes to the reduction in harmful gases in the air. Full article