Compression Ignition Diesel Engine Research Articles

Study on the integration of hydrogen in a multi-cylinder low heat rejection diesel engine using a ternary blend

Among alternative fuels, hydrogen (H2) holds significant promise as both a fuel and an energy carrier. It is expected to become a key alternative fuel in the near future to meet stringent pollution standards. H2 is used in internal combustion (IC) engines, gas turbines, and the aerospace industry due to its non-toxic and odorless nature, high calorific value (CV), and wide temperature range of combustibility. Additionally, it is a long-term renewable energy source that produces fewer pollutants. This study explores the impact of different H2 ratios on combustion behavior, engine performance, and emission characteristics in a dual-fuel compression ignition (CI) diesel engine. The current research focuses on the effect of TB of ethanol, Jatropha methyl ester, and diesel with the induction of H2 with different flow rates in diesel engine in dual fuel mode (DFM). The tests were performed at different engine loads, 25%, 50%, 75%, and 100% at a constant engine speed of 2500 rpm. H2 is inducted at different flow rates like 2, 4, and 6 Litres per minute (lpm). Partially stabilized zirconia (PSZ) is used to coat the cylinder head, piston crown, and valves with a thickness of 0.5 mm. The combined effect of TB fuel and H2 in a CI engine improves combustion and engine performance. At full load condition, brake thermal efficiency (BTE) is improved by 11.5% for TB fuel with H2 at 6 lpm, and exhaust gas temperature (EGT) increased by 12.7%. The cylinder pressure (CP) and heat release rate (HRR) are increased by 7.5% and 10.6% at TB fuel with 6 lpm of H2 induction. The utilization of H2 as an alternative energy source has significant consequences for the future of green energy production.

A Novel PETG Microchannel Reactor for Microwave-Powered Biodiesel Production

Biodiesel stands at the forefront as a replacement for fossil diesel in compression ignition engines, particularly in the transportation sector where diesel engines are the primary movers. However, biodiesel production is hampered by poor heat and mass transfer during the transesterification reaction, leading to long production times and high costs due to inefficient energy utilisation. This study targets heat and mass transfer issues during the production of biodiesel via a synergic approach that combines microwave-assisted heating and microfluidics via a polyethylene terephthalate glycol (PETG) microchannel reactor. The transesterification reaction of palm oil and methanol was investigated using a full factorial design of experiments (DOE) method. Biodiesel yield was quantified via gas chromatographic analysis, and the results were optimised using statistical analysis. Optical analysis of slug quantification within the microchannel revealed that small slugs, smaller than 1 mm, accelerated the transesterification reaction. The composite-optimised experimental results, aimed at minimising energy costs and environmental impacts while maximising fatty acid methyl ester (FAME) yield, indicate a reaction temperature of 50 °C, a catalyst loading of 1.0 wt.%, and a 3:1 methanol to oil molar ratio. Regression analysis revealed that the reaction temperature was statistically insignificant when utilising the PETG microchannel reactor. This key finding positively impacts biodiesel production as it relates to significantly reduced energy intensity, costs, and emissions. Overall, this research work paves a pathway toward an energy-efficient and sub-minute rapid transesterification reaction, highlighting the effectiveness of microwave heat delivery and effects of microfluidics via the PETG microchannel reactor in overcoming heat and mass transfer barriers in biodiesel production.

Optimization of Compression Ignition Diesel Engine Combustion, Emission, and Performance Characteristics at Higher Blends of Biodiesel Using RSM

Optimization of Compression Ignition Diesel Engine Combustion, Emission, and Performance Characteristics at Higher Blends of Biodiesel Using RSM

An overview concerning the utilization of fusel oil as an alternative fuel in the engine applications

Diesel engines will continue to be discussed in the coming years because of their harm to the environment resulting from emitted pollutants. These engines are unrivaled in the transportation industry owing to the high power achieved at high compression ratios. In recent years, studies have been carried out on the use of alternative fuels instead of diesel in compression ignition engines. Fusel oil (FO) is a by-product acquired from several types of agricultural biomass by different techniques. To conclude, in the present paper, researches in the published literature for diesel engines using fuel blends containing FO as an alternative fuel have been reviewed in detail. FO's high octane number, high oxygen content, and low freezing point make it stand out as a fuel additive. In addition, the calorific value of FO is lower than diesel, and its density and viscosity are higher. When FO is infused at different concentrations to diesel fuel (DF) or DF-biodiesel mixtures, fuel consumption increases in compression-ignition engines while engine power decreases compared to reference DF. There is a noticeable decrease in CO and NOx pollutants in fuel blends using FO. The amount of water in the FO has an adverse effect on diesel engines. In the article, firstly, the production and properties of FO are reviewed and its fuel properties are summarized. Then, the effects of diesel/FO and diesel/biodiesel/FO mixtures on engine performance and emissions are discussed. Finally, the positive and negative aspects of FO for diesel engines are summarized.

Study on Combustion and Soot Formation Characteristics of RCCI Engine with Diesel Mixed with PODE Ignited Gasoline

Article Study on Combustion and Soot Formation Characteristics of RCCI Engine with Diesel Mixed with PODE Ignited Gasoline Qian Wang, Botian Guo, Wenjun Zhong *, Peng Jiang *, and Xu Liu School of Energy and Power Engineering, Jiangsu University, Zhenjiang 212013, China * Correspondence: wj_zhong@ujs.edu.cn (W.Z.); jiangpeng@ujs.edu.cn (P.J.) Received: 8 November 2023 Accepted: 23 January 2024 Published: 30 January 2024 Abstract: Polymethoxydimethyl ether (PODE) is a promising clean alternative fuel with the potential to improve carbon emissions from internal combustion engines. However, when used as a sole fuel, its low viscosity leads to increased wear on high-pressure pumps and injectors. Furthermore, its low calorific value makes it unsuitable for direct application in diesel engines. Numerous studies have shown that blending PODE with diesel results in lower soot generation throughout the entire combustion cycle in diesel engines. However, the process of reducing in-cylinder soot generation is not yet clear, necessitating further optical diagnostics of in-cylinder combustion. Therefore, the aim of this study is to investigate the influence of PODE/diesel blend combustion on the combustion characteristics and soot generation properties of reactivity controlled compression ignition (RCCI) diesel engines. The study employs an optical engine and conducts experiments using high-speed imaging and two-color pyrometry. Preliminary experiments indicate that a 50% premixed ratio exhibits better heat release and lower soot generation. Thus, this study explores the effects on in-cylinder combustion and soot generation properties by varying the PODE blending ratio and injection strategy under a 50% premixed ratio. Results indicate that with an increase in PODE blending ratio, both peak in-cylinder pressure and heat release rate decrease, and the combustion duration is prolonged. Compared to diesel, the soot content of P20D80 (20% PODE and 80% diesel) and P50D50 (50% PODE and 50% diesel) is 55.22% and 36.55% respectively, while the heat release is 97.89% and 95.39% of that of diesel. The total amount of soot generated was 55.22% and 36.55% of that of direct injection P0D100, the high temperature area of soot was reduced by 52.9% and 73.32% respectively, the stable value of the average soot temperature was reduced by 6.65 K and 20.25 K respectively, and the average KL factor was the stability values were reduced by 10.35% and 16.12% respectively. P50D50 effectively reduces soot generation while maintaining thermal efficiency. Furthermore, an investigation of injection strategy under P50D50 condition reveals that segmented injection results in lower cylinder pressure, peak heat release rate, and total soot generation compared to single injection. The average temperature of the two-stage injection strategy increased, and the average temperature of soot stable time under the operating conditions of D-40/-20, D-35/-20 and D-30/-20 were 2100.85 K, 2210.16 K and 2192.24 K, respectively. The stable values of the average KL factor of soot under the operating conditions of D-40/-20, D-35/-20 and D-30/-20 were 86.52%, 66.62% and 62.79% of those of S-20, respectively. Although it effectively suppresses soot generation, it comes at the cost of sacrificing a portion of heat release.

Carbon neutrality with ammonia: An analysis of its feasibility as a fuel for diesel engines fuelled with spirulina microalgae and oxygenated additives

Ammonia has emerged as a promising gaseous fuel for replacing conventional fossil fuels and achieving carbon neutrality. This research explores the viability of using ammonia as a fuel in compression ignition diesel engines operating in dual-fuel mode. The study investigates the performance and emission characteristics of diesel engines fueled with ammonia, microalgae-based biodiesel, and their combinations, with the addition of Fe2O3 nanoparticles to enhance combustion efficiency. A series of experiments were conducted using various blends of ammonia, biodiesel, and nanoparticles in a single-cylinder engine. The objective was to assess the impact of ammonia and biodiesel on thermal efficiency and carbon-based emissions. Comparative analysis revealed that ammonia-based fuels exhibited higher brake thermal efficiency and lower carbon emissions compared to traditional diesel fuel. The combination of ammonia, biodiesel, and nanoparticles resulted in an 8.5% increase in thermal efficiency compared to diesel fuel. However, the fuel consumption increased by 18% due to the lower energy density and higher viscosity of the biodiesel blends. Furthermore, the study examined the emissions profile of the tested fuels. The use of ammonia and nanoparticles led to significant reductions in carbon monoxide, hydrocarbon, and smoke emissions. However, there was a slight increase in nitrogen oxides and carbon dioxide emissions, regardless of engine loading conditions. It was observed that the emission of NOx was influenced by combustion delay and autoignition temperature. To mitigate NOx emissions, optimizing the combustion delay and avoiding premixed combustion phases are crucial. Based on the findings, the study concludes that ammonia has the potential to serve as a viable substitute for diesel fuel in engines. Ammonia-based fuels exhibit higher brake thermal efficiency and lower carbon emissions. Future research should focus on optimizing combustion parameters to minimize NOx emissions, thereby facilitating the widespread adoption of ammonia in diesel engines and contributing to the decarbonization of the transportation sector.

Experimental assessment of cork based Botryococcus braunii microalgae blends and hydrogen in modified multicylinder diesel engine

The extended research in using non-edible sources for production of biodiesel has been a boon in today’s need for an alternative fuel. However, the advanced biodiesels have helped to be an alternative fuel to tackle the fossil fuel shortage, the further improvements are needed in the composition of biodiesels. The present research paper gives the detailed explanation about the conversion of the Botryococcus braunii microalgae oil into biodiesel. In addition to the biodiesel blends, hydrogen was added to the injection system as secondary fuel. The addition of hydrogen in biodiesels will reduce the emission of unwanted pollutants. The hydrogenation increases the cetane number of the biodiesel and reduces the free fatty acids to improve the fuel quality. Experimental tests were conducted at full load condition by varying the engine speed from 1000 rpm to 3000 rpm. The hydrogen supply was provided constantly by allowing 5 L per minute into the BB (Botryococcus braunii) biodiesel. The varied proportions of biodiesel was BB0 (Diesel 100 %), BB10 (Botryococcus braunii biodiesel 10 %+Diesel 90 %) and BB20 (Botryococcus braunii biodiesel 20 %+Diesel 80 %) assisted with hydrogen to form BB0H5, BB10H5 and BB20H5. Blends were tested in a multi cylinder, naturally aspirated, compression ignition diesel engines. The different characteristics of the biodiesel with hydrogen in terms of performance, combustion and emission were calculated. The highest engine torque was reported when engine speed was maintained at 1500 rpm. BB10H5 reported the maximum engine torque of 282 Nm followed by BB20H5 and BB0H5. All the blends with hydrogen enrichment reported the highest thermal efficiency and reduced brake specific fuel consumption. Compared to plain diesel, the hydrogen added biodiesel significantly reduced the harmful gas emissions meanwhile the performance qualities were improved. However, there is no sign of reduction in the NOx across various engine speed due to the high cylinder temperatures at higher engine speeds.

Performance and emission characteristics of a diesel engine fuelled by biodiesel from black soldier fly larvae: Effects of synthesizing catalysts with citric acid

Biodiesel has several environmental benefits, such as biodegradability, renewability and lower soot emissions. However, biodiesel has undesirable properties such as higher viscosity and density and low calorific value compared to petroleum diesel, resulting in high Brake Specific Fuel Consumption (BSFC), reduced Brake Power (BP) and increased NOX emissions creating an environmental concerns in biodiesel development. This study investigated the effects of synthesizing transesterification catalysts (CaO and NaOH) with Citric Acid (CA) on the quality of biodiesel and biodiesel blends produced from Black Soldier Fly Larvae (BSFL) (Hermetia Illucens). The quality of biodiesel and blends was determined based on fuel properties, engine performance and emission composition characteristics. The tests were performed on a single-cylinder, four-stroke, Compression Ignition (CI) diesel engine at five loads at a constant speed of 1500 rpm. The results showed that synthesizing the catalysts with CA significantly affected the fatty acid profile of the biodiesel compared to physical fuel properties. B100 (pure BSFL biodiesel) exhibited higher BSFC by 10.57–13.97 % and lower BP by 4.21–7.83 % than diesel fuel. However, the Brake Thermal Efficiency (BTE) of biodiesel was higher than that of diesel fuel by 0.82–4.34 % at maximum load. Synthesizing catalysts with CA improved the viscosity of biodiesel by 0.93–2.81 % and effectively reduced NOX, HC and Smoke opacity by 2.23–3.16 %, 4.95–5.83 % and 20.51–41.15 %, respectively.

Experimental Evaluation of CNG Substitution Ratio on Exhaust Gas Emissions of Diesel/CNG Dual Fuel Combustion

The addition of Compressed natural gas as a complement to diesel in compression ignition engines in dual-fuel combustion mode is a viable technology for increasing efficiency and lowering emissions. This work investigates the impact of a dual-fuel operating mode on the engine exhaust pollutant emissions of a diesel engine using compressed natural gas as the principal fuel and neat diesel as the pilot fuel. Compressed natural gas was injected into an intake manifold of a single-cylinder diesel test engine under different engine operating parameters, and up to 80% substitution was attained. And diesel fuel was injected after the compressed natural gas air mixture was compressed. The tests were carried out at five different compression ratios ranging from 13:1 to 15:1 in steps of 0.5:1. The experiment study revealed that injecting CNG into diesel engines via dual fuel combustion significantly impacted exhaust gas emissions compared to pure diesel combustion. The Carbon monoxide (CO) and hydrocarbon (HC) emissions were increased, while carbon dioxide (CO2), nitrogen oxide (NOX) and smoke opacity were decreased in dual fuel combustion compared to single diesel fuel.

Determination of combustion and emission characteristics of liquid Fischer-Tropsch diesel fuel synthesized from coal in a diesel engine

Fischer–Tropsch (FT) synthesis is a production method that processes a liquid diesel fuel from heavy carbon-containing organic compounds such as coal and biomass. FT synthesis is an essential process in demonstrating the usability of coal-to-liquid fuel in internal combustion engines. This study investigates the effects of using FT diesel fuel synthesized from coal on the combustion characteristics of a single-cylinder common-rail direct-injection diesel engine. The engine tests were conducted at 50% of the wide-open throttle position and fixed engine control parameters (cycle duration, fuel amount, start of injection timing, etc.). As a result of the study, it was observed that the combustion with the use of FT diesel fuel started (almost 1.5 °CA) and completed earlier according to the petroleum-based diesel (D100). The cyclic variations were more stable with FT diesel fuel. With the use of FT diesel fuel, the indicated mean effective pressure was 3% lower, peak cylinder gas pressure was slightly lower, and the combustion noise was 2–3 dB quieter compared to D100. The heat release was higher during the premixed combustion phase at the cycle durations of 67 ms and 55 ms, while it occurred very small at the cycle duration of 86 ms. Significant reductions in CO2 and NOx emissions, which are complete oxidation products, were obtained with FT diesel fuel compared to D100. The fuel properties, combustion characteristics and emission results showed that no further measures should be taken to use FT diesel in compression ignition engines. FT diesel fuel can be safely used as an alternative fuel.

Impact of the JAZARI technology piston motion profile on the indicated thermal efficiency of a 4-cylinder diesel engine

As fuel economy and consumption become global concerns, engine developers strive to reduce fuel consumption. However, due to complexity and development challenges, only a few new engine technologies have been introduced recently. Nevertheless, the market demands more efficient engines, prompting a focus on new mechanisms. This study evaluates a theoretical 4-cylinder Compression Ignition (CI) diesel engine implementing the JAZARI mechanism, which alters piston speed near top dead center TDC claiming a faster combustion, reduced duration, and improved power output. The evaluation compares indicated thermal efficiency, torque, and fuel consumption using a 1-Dimensional simulation model based on the first law of thermodynamics., which then was calibrated using testing data obtained from an engine test cell dynamometer. Two load cases at 2500 RPM were examined, The simulation results indicate that when using the JAZARI mechanism compared with the calibrated conventional mechanism engine, an increase of 1% in thermal efficiency and 2.5% in indicated torque is seen with only reducing the injection duration and timing to fit the JAZARI mechanism piston motion profile, and when aiming for maximum indicated thermal efficiency it was increased by 1.2% and 3.1% in indicated torque, the final results case indicated that when using the JAZARI mechanism, the engine reached the same indicated torque of 295 N.m, with same indicated efficiency of 45.8% with a peak firing pressure of 155 bar, which is almost 30 bar less than the conventional mechanism case, meaning the ability to boost the JAZARI engine with less risk on the engine internals is an advantage.

Evaluating the Operating Parameters of a Compression Ignition Engine Fueled With Waste Cooking Oil—Diesel Blends Using Artificial Neural Network and Ensemble Methods

Abstract Fossil fuels being the primary source of energy for industrial and power sectors are being consumed at an alarming rate. There is a dire need to search for alternative fuels and optimize the performance parameters of internal combustion (IC) engines. Traditional methods of testing and optimizing the performances of IC engine are complex, time-consuming, and expensive. This has led the researchers to shift their focus to faster and computationally feasible techniques like soft computing (SC) and machine learning (ML) algorithms, which predict the optimum performance with a substantial accuracy. This study focuses on the implementation of artificial neural network (ANN) and ensembling methods (random forest regression and extreme gradient boosting algorithm) modeling of a compression ignition (CI) diesel engine run on waste cooking oil (WCO). A single-cylinder, four-stroke, variable compression ratio diesel engine's performance, combustion, and emission parameters have been predicted using ANN and ML approaches. These models have been developed to predict the brake power, brake thermal efficiency, brake-specific fuel consumption, ignition delay, combustion duration, carbon monoxide, carbon dioxide, and oxides of nitrogen. All the models have been trained by tuning and optimizing a different number of hyper-parameters and training algorithms (Levenberg–Marquardt (LM), scaled conjugate gradient, and Broyden–Fletcher–Goldfarb–Shanno). Further the most optimum parameters have been selected using hyper-parameter optimization. The mathematical models are assessed for their generalization capability by subjecting them to a set of new testing data.

A numerical study of piston bowl geometry and diesel injection timing in a heavy-duty diesel/syngas RCCI engine

The current numerical study aims to examine the single and combined effects of various piston bowl geometries, diesel main Start of Injection (SOI) timing, and syngas energy ratio on the combustion characteristics, specific emissions (g/kW·h), energy distribution, and exergy of a heavy-duty off-road Reactivity-Controlled Compression Ignition (RCCI) diesel engine. The examined geometries include the stock chamber (baseline combustion chamber), wide-shallow chamber, dual-swirl chamber, stepped-lip chamber. The main SOI timing was varied from −20 to −5 Crank Angle (CA) After Top Dead Center (ATDC) with 5 CA steps. Also, syngas energy ratio including 0% Conventional Diesel Combustion (CDC) mode, 20%, 40%, and 60% of total fuel energy per cycle. To accomplish this goal, the SAGE combustion model coupled with a reduced chemical kinetic mechanism consists of 360 reactions, and 72 species was applied to conduct this investigation. The numerical findings showed that the use of the wide-shallow chamber extended the engine operable range under diesel-syngas combustion operating conditions. In comparison to the baseline CDC case, the application of the dual-swirl chamber under CDC conditions, and main SOI timing of −15 CA ATDC led to reduction of Carbon Monoxide ([Formula: see text]), Hydro-Carbon ([Formula: see text]), Particle Matter ([Formula: see text]), Carbon Dioxide ([Formula: see text]), Indicated Specific Energy Consumption (ISEC), Gross Indicated Efficiency (GIE), and exergy efficiency but with a Nitrogen Oxides ([Formula: see text]) penalty rate. In general, an increase in the bore to bowl diameter ratio caused a shorter ignition delay period and combustion duration. The utilization of the stepped-lip chamber at both CDC and diesel-syngas combustion operating modes resulted in a shorter ignition delay period, but a longer combustion duration. Nonetheless, the stepped-lip combustion chamber reduced the diffusive flame temperature. Also, it is noteworthy that the utilization of the stock chamber along with the main SOI timing at −5 CA ATDC under diesel-syngas 60% combustion mode is a suitable technique to pass EURO-VI [Formula: see text] and [Formula: see text] emissions regulations.

Comparison of performance and emission characteristics of homogeneous charge compression ignition with conventional compression ignition engine

The performance and emissions of homogeneous charge compression ignition (HCCI) diesel engines were analysed at varying intake air temperatures (Ti) and compared with conventional diesel engines. HCCI engines featured outside fuel–air mixing systems. Diesel was used as a fuel for the testing of port fuel injection pressure (two bars, four bars, and six bars), as well as intake temperature Ti (60 °C, 80 °C, 100 °C, 120 °C, and 140 °C). The outcomes of the experiments presented that both Ti and port fuel injection pressure had a substantial impact on the fuel–air mixture. Up to 120 °C, the blending of air and fuel had a proportionate effect on Ti. When heated above 120 °C, it caused significant knocking and emissions. The Brake thermal efficiency of HCCI is similar to that of diesel engine when HCCI engine operated at an intake air temperature of 120 °C and injection pressure of 4 bar where as in other modes it less than the efficiency of diesel engine. The nitrogen oxide emissions were significantly reduced in the all HCCI engine mode operations compared to diesel engine. The minimum emissions were engine when HCCI engine operated at an intake air temperature of 120 °C and injection pressure of 4 bar. The smoke opacity was significantly reduced in the all HCCI engine mode operations compared to diesel engine. The minimum emissions were engine when HCCI engine operated at an intake air temperature of 120 °C and injection pressure of 4 bar. The HC and CO emissions of HCCI engine at all conditions were slightly higher than the diesel engine. But, the minimum emissions were obtained when HCCI engine operated at an intake air temperature of 120 °C and injection pressure of 4 bar without knocking. Finally, it is concluded that HCCI engine operated at an intake air temperature of 120 °C and injection pressure of 4 bar will give the optimized perform ace and emission characteristics when compared to diesel engine.

How Do Microalgae Biodiesel Blends Affect the Acoustic and Vibration Characteristics of the Direct Injection Diesel Engine: An Experimental Examination

Abstract The noise and vibration characteristics play a vital role in the effectiveness of engine operations and performance of internal combustion engines. Accumulation of the higher amplitude of both noise and vibration affects the comfort of the engine. So far, most of the research done on the performance, combustion, and emission characteristics only. Less importance is shown in the form engine vibration and sounds created by the engine operation. This paper presents and explores the importance and experimental results of noise and vibration by the compression ignition diesel engine with the fuels of diesel and microalgae biodiesel. The produced microalgae biodiesel blends were SMB10%, SMB20%, and SMB30%. The experimental results were conducted at different engine loads varying across 25%, 50%, 75%, and 100%. The inline, four-cylinder, water-cooled, and naturally aspirated DI diesel engine was used as an experimental setup. From the comparative results between the diesel and microalgae biodiesel, it is found that the use of microalgae blended biodiesel reduced the noise and vibration. The higher the percentage of blends, the greater the reduction in sound and vibration will be. Apart from possessing the performance and emission qualities, the microalgae biodiesel blends proved to be an efficient fuel in reduced vibration and noise qualities too. In three directions, the vibrations were measured as lateral, longitudinal, and vertical vibrations. The vibration in the lateral direction was significantly reduced. Compelling the results, it is understood that the use of the microalgae blends can be sustainable from the perspective of engine wear and tear.

Sustainability evaluation, optimization and research dynamics of microalgae methyl ester in a research diesel engine

Renewable energy sources are becoming an increasingly viable alternative energy source for the near future due to increased environmental concerns and increasingly strict energy restrictions. Bioethanol and biodiesel are the most promising biofuel options. In the present study effects of spirulina microalgae biodiesel and diesel blends on compression ignition diesel engines at 1500 r/min utilizing various blends B20, B40, B60, B80, and B100, as well as B0 (diesel), 23.5° before top dead centre and 18.5 compression ratio (CR) at 220 bar. The extreme peak pressures of the engine for B0, B20, B40, B60, B80, and B100 were 103.13, 101.65, 100.25, 98.90, 96.74, and 94.83 bar, respectively. The percentage reduction in ignition delay duration for B20, B40, B60, B80, and B100 was 2.57%, 4.17%, 5.28%, 6.60%, and 8.16% compared to pure diesel. B20 proves to be the most promising biodiesel blend. Analysis of variance analysis was done for experimental data. The response surface method was used to optimize the engine performance and emission parameters for load, blend, and CR variations. Optimized input conditions were found as load 52.27, CR 18.5, and blend B20. The research dynamic analysis was carried out for the sustainability of biodiesel.

Comparison of the Engine Performance of Soybean Oil Biodiesel Emulsions Prepared by Phase Inversion Temperature and Mechanical Homogenization Methods

The engine performance and emission characteristics of burning emulsions of soybean oil biodiesel in a compression-ignition diesel engine prepared through the phase inversion temperature method were compared with those of neat soybean oil biodiesel and the emulsion prepared by the mechanical homogenization method. The engine torque was set constantly at 98 N·m with varying engine speeds. The experimental results show that the emulsion prepared by the method of phase inversion temperature had higher O2 and NOx emissions, a higher excess air ratio, a higher exhaust gas temperature, and a higher brake fuel conversion efficiency than the emulsion prepared by the mechanical homogenization method, which had lower CO and CO2 emissions, a lower equivalence ratio, and lower brake-specific fuel consumption. While the neat soybean oil biodiesel was found to have the lowest fuel consumption rate, brake-specific fuel consumption, and CO and CO2 emissions, it had the highest exhaust gas temperature and brake fuel conversion efficiency, NOx and O2 emissions, and excess air ratio among those three fuels. Therefore, the phase inversion temperature method is considered promising for preparing fuel emulsions as an alternative to petro-derived diesel for compression-ignition engines.

Safe deep reinforcement learning in diesel engine emission control.

A deep reinforcement learning application is investigated to control the emissions of a compression ignition diesel engine. The main purpose of this study is to reduce the engine-out nitrogen oxide emissions and to minimize fuel consumption while tracking a reference engine load. First, a physics-based engine simulation model is developed in GT-Power and calibrated using experimental data. Using this model and a GT-Power/Simulink co-simulation, a deep deterministic policy gradient is developed. To reduce the risk of an unwanted output, a safety filter is added to the deep reinforcement learning. Based on the simulation results, this filter has no effect on the final trained deep reinforcement learning; however, during the training process, it is crucial to enforce constraints on the controller output. The developed safe reinforcement learning is then compared with an iterative learning controller and a deep neural network-based nonlinear model predictive controller. This comparison shows that the safe reinforcement learning is capable of accurately tracking an arbitrary reference input while the iterative learning controller is limited to a repetitive reference. The comparison between the nonlinear model predictive control and reinforcement learning indicates that for this case reinforcement learning is able to learn the optimal control output directly from the experiment without the need for a model. However, to enforce output constraint for safe learning reinforcement learning, a simple model of system is required. In this work, reinforcement learning was able to reduce emissions more than the nonlinear model predictive control; however, it suffered from slightly higher error in load tracking and a higher fuel consumption.

Numerical investigation and Pareto optimization on performance, emission and in-cylinder reforming characteristics for two cylinder reciprocating engine with COx free fuel

The main objective of this study is to introduce the applicability of ammonia to the downsized compression ignition diesel engine for power generation or range extender. For this research objective, the two cylinder engine, which was the result of the previous study, fueled with diesel-ammonia blends was considered and the performance and NOx emission tendency were identified using the numerical method. Ammonia was mixed with diesel via injection at a specific fuel energy fraction (0%, 5%, 10%, or 15%) to evaluate the engine performance and emission characteristics. In addition, concept of “in-cylinder reforming” was introduced adopting negative valve overlap (NVO) by advancing the exhaust valve closing time to investigate the effect of adding ammonia as a hydrogen carrier. Subsequently, the primary variables affecting the brake-specific fuel consumption and NOX are determined via multi-objective Pareto analysis. The optimal Pareto front confirms that exhaust valve timing exerts a greater effect on the performance and emissions than injection timing. Moreover, in-cylinder reformed hydrogen was increased under negative valve overlap strategy.

Exergy, energy, and emissions analyses of binary and ternary blends of seed waste biodiesel of tomato, papaya, and apricot in a diesel engine

• Binary and Ternary Blends of Biodiesel have been tested through IDI–CI Engine to serve as future renewable energy. • Exergy, Energy, and Emissions Were Analyzed at different Engine Work Conditions. • The Binary Blends of Biodiesel Significantly Decrease the Percentage of Heat Loss Exergy. • The Ternary Blends of Biodiesel Drastically Decrease the Heat Transfer Energy Loss. • TAPD Considerably Reduces CO Emissions. Biodiesel is considered as a renewable biofuel-based substitute for fossil diesel as the properties of biodiesel are similar to those of normal diesel fuel. However, biodiesel has some properties which a negative effect on engine combustion. Binary and ternary fuel blends (blends of biodiesels with the opposite properties) are the best environmentally friendly alternative in compression ignition engines. In this paper, the effects of binary and ternary blends of tomato, papaya, and apricot seed biodiesels on the energy and exergy balance as well as emissions on a compression ignition diesel engine were experimentally and theoretically investigated. The obtained results reveal that the maximum and minimum exergy efficiency are related to the biodiesel of tomato-papaya blend at about 29.63% and pure diesel at about 28.46% respectively. Also, the obtained results show that, compared to the tomato biodiesel-diesel blend, using the binary blends decreases the percentage of heat loss exergy by 5.5% and 3.3% on average for tomato-papaya biodiesel -diesel and tomato-apricot biodiesel-diesel, respectively. The results address that the energy percentage of exhaust emissions at the speed of maximum torque and maximum power averaged 30% while this fraction for exergy was about 13%. The emission results show that the minimum oxygen monoxide emissions, which is 0.3% less than that of diesel, is related to the tomato-apricot-papaya biodiesel-diesel ternary blend.