With the aim of CO2 emissions reduction in the maritime sector, dual fuel engines operating on natural gas are the most prominent technical and commercially available solution. A promising variant is the two-stroke high-pressure natural gas injection engine, utilizing diesel pilot fuel injection for ignition of the gaseous fuel while being able to operate in diesel-only mode. In this study, a comparative analysis of the performance and the combustion mechanism of dual fuel and diesel mode for this engine type is conducted using experimental data. Studies based on measurements conducted on actual scale are limited in the literature due to the engines’ sheer size not allowing lab testing. The analysis was conducted using measurements acquired during the factory acceptance tests involving conventional operating data and cylinder pressure data acquired using a piezoelectric sensor. In terms of the mean pressure and temperature, only minor differences were found. The specific fuel consumpti... [more]

The article proposes a method of multipurpose optimization of the size of an autonomous hybrid energy system consisting of photovoltaic, wind, diesel, and battery energy storage systems, and including a load-shifting system. The classical iterative Gauss−Seidel method was applied to optimize the size of a hybrid energy system in a remote settlement on Sakhalin Island. As a result of the optimization according to the minimum net present value criterion, several optimal configurations corresponding to different component combinations were obtained. Several optimal configurations were also found, subject to a payback period constraint of 5, 6, and 7 years. Optimizing the size of the hybrid power system with electric load shifting showed that the share of the load not covered by renewable energy sources decreases by 1.25% and 2.1%, depending on the parameters of the load shifting model. Net present cost and payback period also decreased, other technical and economic indicators improved; ho... [more]

Nowadays, the transport sector is trying to face climate change and to contribute to a sustainable world by introducing modern after-treatment systems or by using biofuels. In sectors such as road freight transportation, agricultural or cogeneration in which the electrification is not considered feasible with the current infrastructure, renewable options for diesel engines such as alcohols produced from waste or lignocellulosic materials with advanced production techniques show a significant potential to reduce the life-cycle greenhouse emissions with respect to diesel fuel. This study concludes that lignocellulosic biobutanol can achieve 60% lower greenhouse gas emissions than diesel fuel. Butanol-diesel blends, with up to 40% butanol content, could be successfully used in a diesel engine calibrated for 100% diesel fuel without any additional engine modification nor electronic control unit recalibration at a warm ambient temperature. When n-butanol is introduced, particulate matter em... [more]

Compression ignition (CI) engines are popular in the transport sector because of their high compression ratio. However, in recent years, it has become a major concern from an environmental point of view because of the emission and depleting fossil fuel. The advanced combustion concept has been a popular research topic in the CI engine. Low-temperature combustion with alternate fuel has helped in reducing the oxides of nitrogen (NOx) and soot emission of the engine. Biogas is a popular substitute of energy especially deduced from biomass because of its clean combustion properties, as well it being a renewable energy source compared to non-renewable diesel resources. In experiments with dual fuel, i.e., conventional diesel and alternate fuel (biogas) were carried out through them. In the present study, an artificial neural network model was used to estimate emissions and check the attributes of performance. Different algorithms and training functions were used to train the models. Howeve... [more]

The development of compression ignition engines depends mainly on using alternative fuels, such as alcohols. The paper presents the results of tests of a stationary compression ignition engine fueled with mixtures of diesel oil and n-butanol with an energy share from 0 to 60%. The combustion and emission results of a dual-fuel engine were compared to a conventional diesel-only engine. As part of the work, the combustion process, including changes in pressure and heat release rate, as well as exhaust emissions from the test engine, were investigated. The main operational parameters of the engine were determined, including mean indicated pressure, thermal efficiency and specific energy consumption. Moreover, the stability of the engine operation was analyzed. The research shows that the 60% addition of n-butanol to diesel fuel increases the ignition delay (by 39%) and shortens the combustion duration (by 57%). In addition, up to 40%, it results in increased pmax, HRRmax and PPRmax. The e... [more]

In this study, biodiesel fuel with a ratio of 20% volume (B20) was used on vehicles that are used in common rail injection systems, complying with Euro2 emission regulations. Laboratory and road tests were conducted to evaluate the effects of B20 on performance, emissions and engine components. Using diesel fuel and B20 as reference fuels, tests were conducted using Euro2 vehicle technology to investigate the effects on emissions, fuel consumption, and power. Durability testing was run for travel distances covering 40,000 km under various road and environmental conditions, while vehicle performance and emissions tests were conducted using the ECE R84-03 and ECE R101 test methods, respectively. The results show that B20 has lower CO and hydrocarbon (HC) emissions for every distance travelled, with an average of around 30%. Particulate emission was a bit lower, averaging 3.4% for B20 compared to B0, while NOx was found to slightly increase at around 2% for B20. Due to its lower calorific... [more]

Philippine off-grid islands are mostly electrified by diesel generators, resulting in costly electricity that is interrupted by fuel supply disruptions. The archipelagic nature of the country also impedes off-grid electrification due to the high capital cost of grid extension. Transitioning from diesel-only systems to hybrid renewable energy systems and interconnecting the island microgrids can solve these problems while promoting cleaner energy production. In this work, a comparative study on decentralized and clustered hybrid renewable energy system microgrids in the Polillo group of islands in the Philippines, using HOMER Pro, was performed. Microgrids comprising solar photovoltaics, lithium-ion battery energy storage, and diesel generators were designed on each island. Clustered systems encompassing multiple islands in the island group were simulated by also considering the least-cost interconnection paths. The techno-economics of each decentralized or clustered system and the four... [more]

The article presents the results of a study aimed at creating a mathematical model of thermodynamic processes in the intake manifold of a forced diesel engine, taking into account the features of simultaneous injection of fuel and water into the collector. In the course of the study, the tasks of developing a mathematical model were solved, it was implemented in the existing software for component simulation “Internal combustion engine research and development” (ICE RnD), created using the Modelica language, and verification was undertaken using the results of bench tests of diesel engines with injection fuel and water into the intake manifold. The mathematical model is based on a system of equations for the energy and mass balances of gases and includes detailed mathematical submodels of the processes of simultaneous evaporation of fuel and water in the intake manifold; it takes into account the effect of the evaporation of fuel and water on the parameters of the gas state in the inta... [more]

Multiple injection strategies have increased their capabilities along with the evolution of injection system technologies up to the point that nowadays it is possible to inject eight different pulses, permitting to improve the engine performance, and consequently, emissions. The present work was realized for two simplified strategies: a pilot-main and a main-post, in order to analyze the influence of an auxiliary pulse on the main and otherwise, in reactive conditions for two pilot/post quantities and four hydraulic dwell times. The study was carried out by employing two optical techniques: diffused back-illumination with flame bandpass chemiluminescence for measuring soot, represented by soot-maps distribution, and single-pass schlieren for ignition delay (ID). Furthermore, a novel methodology for decoupling the start of combustion (SOC) of the second pulse was developed and successfully validated. From the ignition delay results, it was found for all test points that the pilot inject... [more]

Currently, the global issue for countries is the search for raw materials and the production of bioenergy within their country; bioenergy also includes biodiesel fuels. One of the most promising biodiesel fuels is the green diesel fuel produced by the hydrogenation of vegetable oils. Three methods have been proposed to obtain high-quality biodiesel and environmentally friendly diesel fuel: compounding green diesel with hydro-treated diesel fuel, compositions of the improved fuel «green diesel» with bio-additives, and two-component mixtures of environmentally friendly diesel fuel with bio-additives. Using these methods, it is possible to produce fuel for diesel engines with improved lubricating properties, the wear scar diameter is reduced to 232 microns, according to EN 590: 2009, this value standard is up to 460 microns. The optimal quantitative composition of three-component environmentally friendly diesel fuel with improved lubricity was established. The dependence of the change in... [more]

The paper is devoted to the analysis of the operating cycle of a high-pressure injection pump used in common rail systems. The investigation is based on experimental activities, and it is carried out in a novel pump set-up that allows measurements of the instantaneous pressure in the piston working chamber. A single plunger pump has been equipped with a piezo-resistive pressure transducer which allows for the measurement of the pressure signal during pump operation on a test rig. The paper describes the experimental set-up, the modified injection pump equipped with the pressure transducer, and the experimental tests carried out. Main results obtained using a standard commercial diesel fuel are discussed at first; secondly, the focus moves on to the use of an alternative fuel (biodiesel) whose features in terms of bulk modulus, viscosity, and density significantly differ from the reference fuel. Based on the characteristics of the pump operating cycle, the fuel suction and delivery proc... [more]

This contribution focuses on utilizing blended biofuels of rapeseed oil and methanol with diesel. Rapeseed is one of the most cultivated energy crops in Europe, and its purpose in the blends is to increase the bio-content in test fuels. The purpose of methanol in the blends is to increase bio-content and compensate for the higher viscosity of the rapeseed oil. As methanol is almost insoluble in diesel and rapeseed oil, iso-butanol is used as a co-solvent. The fuel blends were tested in volumetric concentrations of diesel/rapeseed oil/methanol/iso-butanol 60/30/5/5, 50/30/10/10, and 50/10/20/20. Diesel was used as a reference. The measurements were performed on a turbocharged diesel engine Zetor 1204, loaded using the power-takeoff shaft of the Zetor Forterra 8641 tractor. In this paper, the effect of the blended fuels on performance parameters, engine efficiency, production of soot particles, and regulated and unregulated emissions are monitored and analyzed. It was found that engine p... [more]

Within this work the effects of blending oxymethylene ethers (OMEn) to a diesel surrogate (50 mol% n-dodecane, 30 mol% farnesane, and 20 mol% 1-methylnaphthalene) were investigated by performing two different types of experiments: measurements of the sooting propensity and of the laminar burning velocity, each in laminar premixed flames. For the sooting propensity, OME3, OME4, and OME5 were considered as blending compounds—each in mass fractions of 10%, 20%, and 30%. The sooting propensity was found to depend strongly on the OMEn blending grade but not on its chain length. In addition, the effect on the laminar burning velocity was studied for OME4 and the admixture of 30% OME4 with diesel surrogate for the first time. This admixture was found to lead to increased burning velocities; however, much less than might be foreseen when considering the respective values of the neat fuels.

How to improve the combustion efficiency and reduce harmful emissions has been a hot research topic in the engine field and related disciplines. Researchers have found that nano-additives to diesel-biodiesel fuel blends have achieved significant results. Many research results and both current and previous studies on nanoparticles have shown that nano-additives play an essential role in improving the performance of internal combustion engines and reducing the emission of harmful substances. This paper summarizes the recent research progress of nanoparticles as additives for diesel-biodiesel fuel blends. Firstly, the excellent properties of nanoparticles are described in detail, and the preparation methods are summarized and discussed. Secondly, the effects of several commonly used nanoparticles as diesel-biodiesel fuel blends on combustion performance and harmful substances emissions in terms of combustion thermal efficiency, brake specific fuel consumption, CO, UHC and NOx, are reviewe... [more]

To investigate primary breakup close to an injector, this paper presents both experimental and numerical research on high-pressure common-rail diesel injection. We propose a new method named SD-ELSA model to realize automatically identifying droplet features for high-pressure diesel spray based on the classic ELSA (Eulerian Lagrangian Spray Atomization) model; this method is suitable for varied injection operation conditions. The SD-ELSA first identifies the liquid bulk due to breakup of the continuous phase in near field, and then converts the Eulerian liquid bulk into Lagrangian particles to complete the calculation of the total spray atomization. The SD-ELSA model adopts two key criteria, i.e., the sphericity (S) and the particle diameter (D); the qualified liquid mass is transformed into Lagrangian particle, realizing the coupling of the Eulerian−Lagrangian model. The SD-ELSA model illustrates the total diesel spray atomization process from the breakup liquid column to the droplets... [more]

The purpose of the following article is to present the situation of the energy market from a household perspective between 2010 and 2020 in selected EU countries (the group of member states which joined EU after 2004). The selected countries when joining the EU had similar economic indicators and to some extent were similar in other macro-economic situations (personal income, unemployment rate, GDP level and annual growth). This article analyzes the past and current situation of the household ability expenditure on electricity and energy resources (petrol—eurosuper 95 and diesel and natural gas), taking into account price, tax conditions and the real possibility to purchase the analyzed energy sources (based on annual net salaries). The paper includes the conclusions and prospects for the future. The main objective of the study is to determine the ability amount of expenditure on electricity, natural gas and liquid fuels by household in the countries that joined the European Union afte... [more]

This paper describes the simulative approach to calibrate an already extremely highly turbocharged industrial diesel engine for higher low-speed torque. The engine, which is already operating at its cylinder-pressure maximum, is to achieve close to 30 bar effective mean pressure through suitable calibration between the compression ratio, piston-bowl shape and injection strategy. The basic idea of the study is to lower the compression ratio for even higher injection masses and boost pressures, with the resulting disadvantages in the area of emissions and fuel consumption being partially compensated for by optimizations in the areas of piston shape and injection strategy. The simulations primarily involve the use of the 3D CFD software Converge CFD for in-cylinder calibration and a fully predictive 1D full-engine model in GT Suite. The simulations are based on a two-stage turbocharged 1950 cc four-cylinder industrial diesel engine, which is used for validation of the initial simulation.... [more]

Methods for obtaining efficient sorption materials based on highly porous melamine and polyurethane matrices modified with reduced graphene oxide were developed. These materials are promising for solving environmental problems such as water pollution with organic products by sorption treatment. Reduced graphene oxides (rGOs) were synthesized from graphene oxide suspensions using potassium hydroxide, ascorbic acid or hydrazine hydrate. Composites with obtained rGO and melamine and polyurethane foam were produced for further characterization. The composites demonstrate high sorption of organic pollutants (oil, diesel fuel and gasoline) and low sorption of water. The composites were comprehensively analyzed by physicochemical techniques (SEM, XPS, Raman spectroscopy, UV−Vis) to elucidate the mechanism of sorption.

The unrestricted consumption of fossil fuels negatively impacts the economic, social and environmental aspects, observed from a sustainable perspective. Therefore, it is necessary to develop and adopt skills that enable the monitoring and mitigation of risks to the environment. In view of this, we propose a method with multiple approaches emphasizing a three-dimensional perspective of energy consumption by diesel engines, which represent one of the main pollutants emitters in transport. As a methodology, fuzzy logic was adopted, together with a recognition system, in order to mitigate the uncertainties inherent to the applied data. The procedure was applied to the city of Rio de Janeiro, Brazil, with information collected from seven toll plazas and a radar with volumetric counting. The results indicate a good adherence of the sustainability index to real cases, allowing a better observation of changes in environmental criteria and a more efficient inspection in the application of good... [more]

2-methyltetrahydrofuran (MTHF2) has been recently regarded as a promising alternative engine fuel. However, the chemical reaction mechanism for MTHF2 combustion in the engine has not been reported to date. In this study, a reduced diesel/MTHF2 reaction mechanism with only 78 species among 233 reactions was constructed for diesel/MTHF2 dual-fuel engine simulations. Firstly, a diesel surrogate mechanism involving the sub-mechanisms of n-decane, iso-octane, methylcyclohexane (MCH), toluene, a reduced mechanism of C2-C3 species and a detailed mechanism of H2/CO/C1 was selected. Secondly, a skeletal MTHF2 mechanism containing 54 species and 294 reactions was formulated under engine-relevant conditions using combined mechanism reduction methods. Thirdly, a reduced sub-mechanism of MTHF2 oxidation with 11 species and 13 reactions was extracted and combined with the four-component diesel surrogate fuel mechanism. Subsequently, the reduced diesel/MTHF2 mechanism was obtained by improving the co... [more]

Non-road sectors, such as agriculture and construction machinery, require high energy densities and flexibility in use, which is why diesel engines are mainly used. The use of climate-neutral fuels, produced from renewable energies, such as Oxymethylene Ether (OME) as a diesel substitute, can significantly reduce CO2 and pollutant emissions in these sectors. In addition to CO2 neutrality, OME also offers improved combustion characteristics compared to diesel fuel, eliminating the soot−NOx trade-off and thus enabling new opportunities in engine design and calibration. In this paper, the combustion of pure OME on a close-to-production, single-cylinder non-road diesel engine with a pump−line−nozzle injection system is analyzed. A variation of the center of combustion at constant power output was performed for diesel and OME at different operating points. Two injectors were investigated with OME. A study on ignition delay and a detailed thermodynamic analysis was carried out. In addition,... [more]

The present work is focused on the assessment of the performance and fine particulate matter emissions (PM2.5) of a turbocharged four-cylinder direct injection diesel engine operating under dual-fuel mode with Liquefied Petroleum Gas (LPG). For load levels of 30%, 60% and 100%, measurements were taken, keeping the engine speed constant at 2200, 2500 and 3200 rpm, while the engine knock detonation was detected through a non-invasive internal system. According to experimental measurements, the abnormal knock combustion occurred at full load operation with a maximum LPG energy fraction of ~60%. The brake fuel conversion efficiency increased by 2.6% with an LPG energy fraction of 10%, where a fuel saving of 11.9% was achieved with respect to the diesel-only operation. The reduction of diesel consumption was around 50% with respect to 100% diesel operation at full load operations, where the highest brake fuel conversion efficiency was achieved. The brake fuel conversion efficiency decreased... [more]

Affordable and clean energy for any rural community is crucial for the sustainable development of the community and the nation at large. The utilization of diesel-based power generation is one of the barriers to the sustainable development of these communities. Such generations require fuel that has a volatile market price and emits massive greenhouse gas emissions. This paper presents the design, modeling, and simulation of a hybrid power system for a rural area in the Sultanate of Oman that aims to reduce daily consumption of diesel fuel and greenhouse gas emissions. Hybrid Optimization of Multiple Energy Resources (HOMER) is utilized to model multiple energy mix hybrid systems and to propose the best optimal energy mix system for a selected community. In addition, Electrical Transient Analyzer Program (ETAP) software is employed to assess hybrid system operational performances, such as bus voltage profiles and active and reactive power losses. This study revealed that the PV−wind−di... [more]

The coupling of Eulerian and Lagrangian methods in the Eulerian−Lagrangian Spray Atomization (ELSA) approach is critical. This study proposes an equation for the primary breakup particle diameter D of a diesel fuel spray and adopts it as a key transition criterion for coupling. A three-dimensional diesel spray is modeled by the large-eddy simulation (LES) approach. This improved ELSA simulation was conducted using various transition criteria for particle diameter Dcr. The results show that fuel spray experiences two stages: stage I, when a liquid column appears without a dispersed phase, and stage II, when primary breakup occurs with many discrete particles. Although Dcr has little influence on the macro-spray characteristics, such as top penetration distance S and spray cone angle θ, it has significant effects on discrete particles, such as their number, average diameter, distribution and location, and spray cone area. Dcr should be determined on the basis of actual operating conditio... [more]

Algae are regarded among the most favorable feedstocks for producing sustainable biodiesel and utilizing it in diesel engines. Additionally, ethanol addition further enhanced the performance and reduce greenhouse emission. Algae biodiesel was produced, and an experimental study was performed to understand the diesel engine performance and emissions characteristics using different fuel blends by varying the ratio of diesel, biodiesel, and ethanol, such as D100, B10, B20, B5E5, and B10E10 (where number shows the percentage of the respective fuel). It was found that brake thermal efficiency was reduced by 0.49% and 1.29% for B10 and B20 blends, while the addition of ethanol enhanced the BTE by 0.37% and 1.60% respectively. However, SFC increases by 1.45%, 2.14%, 3.18%, and 3.78% respectively for B10, B20, B5E5, and B10E10 with respect to diesel fuel. Combustion characteristics were increased with increasing concentration of biodiesel and ethanol addition. Particulate matter, smoke emissio... [more]