Cycle Diesel Engine Research Articles

Application of DieselB10 formulations with short-chain alcohols in diesel cycle engines: phase equilibrium, physicochemical and thermodynamic properties and power curves

Application of DieselB10 formulations with short-chain alcohols in diesel cycle engines: phase equilibrium, physicochemical and thermodynamic properties and power curves

운항 중 EGR이 2행정 사이클 디젤 엔진의 성능에 미치는 영향

운항 중 EGR이 2행정 사이클 디젤 엔진의 성능에 미치는 영향

Use of Soybean Oil like as Fuel for Diesel Cycle Engine

Diesel fuel price is rapidly increasing burdening the agricultural production costs. Additionally, diesel is contributing to a significant amount of life cycle greenhouse gases emissions. Strategically, using agricultural feedstock, such as soybean oil, will reduce fossil fuel price volatility and carbon footprint from agriculture. Although cheaper than biodiesel, use of pure soybean oil has shown to damage a regular diesel engine because of its high viscosity. In this work, a novel technology was developed and tested to overcome this problem by fueling a direct injection Diesel engine with refined soybean oil (edible oil) heated by engine coolant and exhaust gases. Thermal efficiency, air/fuel ratio, fuel injection timing, exhaust temperature and exhaust emissions were evaluated. The major finding of this study was to identify the feasibility of running a modified engine properly with heated soybean oil. The results showed that soybean oil use reduces emissions of nitrogen oxides, but contributes both to lower thermal efficiency and higher emissions of other products such as carbon monoxide and particulate matter compared to fossil diesel. Despite these negative results, solutions to reduce pollutant emissions are feasible.

Desempenho de um motor diesel utilizando diferentes misturas de biodiesel e configurações de injeção

ABSTRACT Diesel cycle engines are widely used in a wide range of agricultural activities. Recently, with the increasing use of biodiesel mixed with petroleum diesel and the introduction of pollutant emission regulations for agricultural and road machinery, there has been a growing migration from mechanical to electronic fuel injection systems. In this experiment, the primary aim was to verify the behavior of a diesel engine, electronically managed, with controlled variation of the fuel feeding system parameters (injection time and volume injected). A four-cylinder agricultural tractor with a turbocharged engine and a common rail electronic fuel injection system was used. Tests with diesel B10 and blends of 20 and 30% biodiesel were carried out, all with 10 ppm of sulfur and the injection system electronically reprogrammed. The tests were performed under full engine load from 1,300 to 2,000 rpm. The torque, power and fuel consumption were evaluated. Advancing the injection point increased the power and decreased the specific fuel consumption for all fuels. The greater amount of injected fuel provided average power gain of up to 14.96% and average torque gain of 15.50%.

Study on the Ignition Mechanism of Closed Cycle Diesel Engine System with Liquid Oxygen Carbon Sequestration

Study on the Ignition Mechanism of Closed Cycle Diesel Engine System with Liquid Oxygen Carbon Sequestration

Assessment of Salicylic Acid in Castor Oil Content Increase in Emissions of Its Biodiesel Blends

Ricinus communis is a species distributed worldwide. Its seeds are used to produce castor oil, which can be used for the production of biofuels; yield improvement can be achieved with elicitors that are substances of biological origin that can induce increased productivity of primary and secondary metabolism, when applied to plants. Salicylic acid (SA) is a natural constituent of plants, and applied exogenously acts as an elicitor. The aim of this work is to evaluate the oil content of castor bean plants elicitated with 900, 600, 300, and 100 µM of salicylic acid and its emissions derived from biodiesel made with the oil in blends (0, 10 and 20%) with commercial fuel in a 296 cc diesel cycle engine; elicitation was foliar sprayed. The oil content increased 39% when 900 µM SA was applied compared to control, and the evaluation of emissions showed the maximum reduction with 20% of Ricinus communis biodiesel (RCB) in all different RPM rates. Otherwise, the use of SA could be a method to increase oil content in castor plants as there is no difference in emission reduction derived from the SA application compared to control.

Study on a Novel Variable Valve Timing and Lift Mechanism for a Miller Cycle Diesel Engine

Thermal efficiency and power density improvement are the main research foci of the literature on diesel engines. The Miller cycle is considered to be one of the most promising methods of diesel engine operation. In this study, a fully variable valve timing and lift mechanism (CD-HFVVS) was studied to determine the possibility of a Miller operation. Firstly, the valve seat impact buffer in the mechanism was tested, which proved that the buffer can effectively eliminate the valve seat impact. Then the influences of different speeds and oil temperatures were studied. The results show that the valve opening duration is prolonged when engine speed increases, and the valve lift and duration are reduced while the oil temperature increased. The valve timing and lift can be fully adjusted by changing the oil discharge position and the initial plunger position, which further proves that CD-HFVVS can achieve the performance optimization of the Miller cycle. By using the mechanism, a single cylinder test was performed. By using variable inlet valve timing, the fuel efficiency can be effectively improved and the peak pressure and in-cylinder average temperature can both be suppressed.

Study on the closed-loop combustion control for a diesel engine by using a dynamic-target online prediction model

In-cylinder pressure-based closed-loop combustion control is a critical technology used to address the issue of cylinder-to-cylinder inhomogeneity throughout the life cycle of a modern diesel engine. Nevertheless, closed-loop combustion control technology (CLCC), which requires a reference or set-point that the control attempts to achieve, causes an increase in the operating maps and the complexity of the calibration effort. In this study, a reference governor-based combustion control (RGCC) is developed in order to reduce the cylinder-to-cylinder combustion dispersions and the calibration effort associated with enabling of the CLCC simultaneously. The RGCC consists of a dynamic-target online prediction model and an indicated mean effective pressure (IMEP) control strategy. The dynamic-target prediction model is designed based on the IMEP of the engine real-time tests; it uses a modified Kalman filter algorithm, which provides the set-point value for the IMEP control strategy. The effectiveness of the proposed RGCC is experimentally validated on a commercial diesel engine test bench under steady-state and transient-state conditions. The experimental results show that the RGCC displayed far better transient tracking performance than the closed-loop IMEP control based on MAP. Furthermore, the controller can effectively reduce cylinder-to-cylinder IMEP variations under steady-state and transient-state conditions.

Investigation of the Effect of Simulated Atmospheric Conditions at Different Altitudes on the Combustion Process in a Heavy-Duty Diesel Engine Based on Zero-Dimensional Modeling

Abstract Plateau diesel engines suffer from increased fuel consumption and deteriorating emissions. These problems were mainly caused by the combustion worsening inside the chamber. However, limited research has been done specifically on the effect of altitude on the combustion process of diesel engine cycles, which would obviate the feasibility of optimizing high altitude engines. As a result, the goal of this study was to apply the zero-dimensional modeling approach to deeply analyze the influence of altitude on diesel engine combustion. A triple Wiebe function model was calibrated based on the experimental results of a turbocharged direct injection compression ignition engine operating at simulated atmospheric conditions from sea level to 5000 meters, where only the effect of pressure reduction was considered, but the intake temperature and oxygen to nitrogen ratio were kept constant. The analyses indicated that the increase in altitude lengthened the ignition delay, resulting in more fuel fraction being burned in the premixed combustion stage and therefore extending the duration of this phase. As for the main mixing-controlled combustion phase, operation at high altitude retarded the combustion initiation angle, advanced the combustion end angle, shortened the burning duration, and reduced the diesel mass burned in this stage. Moreover, the higher altitude operation increased the energy release and prolonged the duration of the late combustion period, which was detrimental to clean emissions. All these impacts contributed to the reduced thermal and combustion efficiency of the highland engines. However, the engine phasing did not change with increasing altitude, suggesting that it was mainly the combustion degradation that caused the reduction in power output. Consequently, finding solutions to improve the spray formation quality or the spray spatial distribution in lower density backgrounds is the key to compensate for the altitude negative effects.

1D diesel engine cycle modeling integrated with MOPSO optimization for improved NOx control and pressure boost

In current investigation, one dimensional gas dynamic and chemical species prediction are simulated according to diesel engine with air cooler and catalyst. The results of engine cycle modeling are then verified with experimental data and the robust validation is obtained. The key parameters of air/fuel ratio, compression ratio, swirl number, coolant temperature, and air temperature of the heat exchanger are taken as input parameters for NOx reduction and pressure increase by multi-objective particle swarm optimization (MOPSO). According to merit function, NOx reduction is weighted two times the pressure increase, as a result out of 80 generated design ID78 is chosen as the best objective. The best design is characterized with high air temperature, swirl number, and compression ratio. It is found that swirl number is a dominant factor for NOx reduction and compression ratio for pressure increase. The best objective case is capable of 4.8% NOx reduction and 5.9% increase of pressure, however the best objective results in unfavorable torque decrease since the NOx reduction is biased. The best solutions also are benefited with 1.6% less wallheat loss due to lower diesel fuel mass injection.

PRODUCTION CHARACTERIZATION AND TESTING OF SOYBEAN BIODIESEL IN A DIESEL CYCLE ENGINE

The characteristics of the biodiesel produced by the transesterification reaction of soybean oil with anhydrous ethanol, catalyzed by sodium hydroxide and its thermo-oxidative stability, were investigated by thermal analysis and viscosity. It was analyzed density at 20 °C, sulfur content, cetane number, carbon residue, iodine index, acidity, sulphated ash, the total content of glycerin and unreacted fatty acids. The synthesis of biodiesel via ethanolic processed in a Pyrex glass reactor with 2/1 molar ratio triglyceride/anhy-drous ethanol and 1% of catalyst, 60 °C. After the reaction, the phases were separated and glycerin was removed. The biodiesel was washed with 0.1M HCl solution, at ~ 70 oC for neutralization. The physicochemical analysis, all parameters for biodiesel met the requirements of the ANP Technical Standards. From the produced biodiesel, binary mixtures were made with diesel in the proportions of 2, 5, 10, 15, 20 and 30%. The objective was to study the behavior of mixtures in a diesel cycle engine coupled to a dynamometer of Eddy Current. In this study of burning biodiesel blends in diesel engine were analyzed and compared with pure diesel parameters: consumption, efficiency, performance, torque and power. The results showed that the mixtures had very similar properties and performance to pure diesel by mixing 20%. To the mixture with 30% there has been a significant drop in torque and power and slight increase in consumption. Thus, it was shown that soybean oil biodiesel, mixtures of 2% to 30%, is applicable as an alternative fuel aptly, for the diesel cycle engines, because it is a renewable and environmentally friendly fuel.

Tempo de aquecimento e número de ensaios para avaliação do desempenho de um motor de ciclo Diesel

ABSTRACT: This research determined the engine warm-up time and the number of tests that must be carried out to obtain the performance parameters of a Diesel cycle engine. To this end, an agricultural tractor coupled to an eddy current dynamometer via a power take-off was used. Pure biodiesel (B100) was used as the fuel, and the hourly consumption was determined by means of a flowmeter. Data regarding torque, power, and hourly and specific fuel consumption was collected and analyzed at three engine warm-up times (20, 60, and 100 min). To determine the number of tests, 18 dynamometric tests were carried out to verify which of those presented the smallest experimental error, through the smallest coefficient of variation. No difference was observed in relation to the warm-up time for the analyzed variables, with a time of 20 min being enough to start the engine performance evaluations. In total, four trials were sufficient to assess engine performance and reduce experimental error.

Synthesis and physico-chemistry properties of a diesel-like fuel produced from waste polypropylene pyrolysis oil

In this work, pyrolysis experiments were carried out in a stainless steel semi-batch reactor to produce a diesel-like fuel from waste polypropylene (PP). Aiming to maximize the liquid oil yield, the optimal reactor operating conditions (e. g. heating rate, batch time, degradation temperature, and N2 flow rate) was obtained by the investigation of the thermal behavior of the waste PP using Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis (TGA). The waste PP pyrolysis oil was successfully purified by adsorption onto activated carbon, resulting in a colorant removal percentage of 49.56% as well as in the removal of the particle matter. The functional groups of purified waste PP pyrolysis oil (PWPO) and the Brazilian commercial S-10 diesel fuel were obtained and compared using Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography Coupled to Mass Spectrometry (GC-MS). According to the experimental results, the proposed thermal pyrolysis process has shown a very high liquid oil yield of about 94 wt%, and fuel heavy and light hydrocarbons were identified in PWPO. It was observed that PWPO has physico-chemistry properties similar to those of commercial S-10 diesel fuel, enhancing the high lower heating value (LHV) of about 43.06 MJ/kg. The work findings pointed out the synthetic diesel-like fuel as a promising alternative for cycle diesel engines, dropping the use of fossil fuels without reducing energy efficiency.

Perspective Use of Fast Pyrolysis Bio-Oil (FPBO) in Maritime Transport: The Case of Brazil

The maritime transportation sector (MTS) is undertaking a major global effort to reduce emissions of greenhouse gases (GHG), e.g., sulfur oxides, nitrogen oxides, and the concentration of particulates in suspension. Substantial investment is necessary to develop alternative sustainable fuels, engines, and fuel modifications. The alternative fuels considered in this study include liquified natural gas, nuclear energy, hydrogen, electricity, and biofuels. This paper focuses on biofuels, in particular fast pyrolysis bio-oil (FPBO), a serious partial alternative in MTS. There are some drawbacks, e.g., biofuels usually require land necessary to produce the feedstock and the chemical compatibility of the resulting biofuel with current engines in MTS. The demand for sustainable feedstock production for MTS can be overcome by using cellulose-based and agroforestry residues, which do not compete with food production and can be obtained in large quantities and at a reasonably low cost. The compatibility of biofuels with either bunker fuel or diesel cycle engines can also be solved by upgrading biofuels, adjusting the refining process, or modifying the engine itself. The paper examines the possibilities presented by biofuels, focusing on FPBO in Brazil, for MTS. The key issues investigated include FPBO, production, and end use of feedstocks and the most promising alternatives; thermal conversion technologies; potential applications of FPBO in Brazil; sustainability; biofuels properties; fuels under consideration in MTS, challenges, and opportunities in a rapidly changing maritime fuel sector. Although the focus is on Brazil, the findings of this paper can be replicated in many other parts of the world.

DESEMPENHO ENTRE MOTORES CICLO DIESEL: UTILIZAÇÃO DE ÓLEO DIESEL E BIODIESEL

Sustainable development practices are important to ensure high standards of quality in various topics, with an emphasis on social and ecological issues, also known as sustainable issues. Studies that comparatively analyze conditions intrinsic to the operation of engines that use more environmentally friendly combustion media. The present study is justified by the importance of contextualizing the environment related to the performance of diesel cycle engines powered by diesel and biodiesel. A study was carried out in the literature on the feasibility of using biodiesel on a commercial scale, preserving the same standards of effectiveness present in these engines, when fueled with diesel oil. The general objective of this study was to perform a comparative analysis of the performance of diesel cycle engines with diesel and biodiesel and to identify issues related to the efficiency and durability of these engines. The present study is classified as a bibliographic review search, seeking information in the scientific field that deals with the topic about diesel oils and biodiesel in diesel cycle engines. To this end, qualitative research was carried out with a descriptive approach that analyzed the performance of diesel cycle engines fueled with different types of fuel oils. Research was done in the library of Faculdade Pitagoras, internet and Scielo, CAPES and Spell repositories so that it is also possible to analyze the development of scientific knowledge on the proposed themes. This study allowed us to understand different aspects that limit the use of traditional fuels, of fossil origin, and biodiesel, considered an alternative fuel. It was possible to identify different aspects that make the use of these fuels feasible in different situations. It was possible to know numerous advantages, disadvantages, characteristics, and limitations of biodiesel and comparing them to fossil fuel was essential to understand the importance of analyzing in a clear and impartial way all aspects that touch such concepts.

The Practical Range of Cut Off and Compression Ratios for a Diesel Cycle Engine

The Practical Range of Cut Off and Compression Ratios for a Diesel Cycle Engine

WITHDRAWN: Effect of tertiary butyl hydroquinone on diesel engine performance fuelled with lemon grass oil

Biodiesel is a biofuel that originates from renewable sources (oils and fats). It displays fuel properties similar to diesel Thus, biodiesel can be utilized in diesel cycle engines, without the need for adaptation. Many vegetable oils have been tested all over the world but due to high viscosity and market prices compared to diesel, these oils are not used commercially. But they can be blend with diesel to form biodiesel. In this study the lemongrass oil is blended with diesel in the ratio of 3:7. Further to study the impact of antioxidants namely, Propyl Gallate (PG) and tertiary butyl hydroquinone (TBHQ), have been added using a sonicator in different concentrations of 300 ppm, 600 ppm and 900 ppm to the biofuel. The samples were tested for its property, GC (gas chromatography) and tested for performance and emission in a VCR diesel engine and compared to diesel. The tests showed that antioxidants gave higher Brake thermal Efficiency (BTE) but lower SFC than diesel. The samples with antioxidants showed reduction in emission of Carbon monoxide (CO), Oxygen (O 2 ) and Hydrocarbon (HC). TBHQ showed reduction of Nitrous Oxide (NO X ). Overall except for NOx emissions PG performed better than TBHQ, hence PG is preferred over TBHQ.

Effects of design and operating parameters on the performance of a quasi-realistic Diesel cycle engine

Although Diesel engines have begun to be abandoned in the automotive industry due to the emission legislations of the world, they are still widely used in generators, work machines, agricultural machines, and heavy vehicles due to their high power density and thermal efficiency. The classical Diesel cycle, which is the thermodynamic cycle of Diesel engines, was developed by taking into account irreversibilities, heat transfer losses, friction, and gas exchange process, and a quasi-realistic Diesel cycle was obtained. Also, the working fluid of the Diesel cycle has been accepted as an air-fuel-residual gas mixture instead of air. This Diesel cycle model is very useful to examine the effect of Diesel engines' design and operating parameters on engine performance. For this study, the effect of variation in equivalence ratio, stroke-bore ratio, and compression ratio on engine performance was examined. Thermal efficiency, maximum temperature, exhaust temperature, fuel consumption, and specific fuel consumption are used as engine performance parameters. The characteristics and operating conditions of a Diesel engine in a power generator were used for the numerical study. Engine performance increased by increasing the equivalence ratio, which is the engine operating parameter. When the compression ratio, which is the structural parameter, increased, the engine performance increased, but the maximum temperature also increased, although it was not desired. Therefore, it is necessary to optimize the compression ratio and the maximum temperature. Again, when the stroke-bore ratio, which is a structural parameter, was increased, engine performance decreased, but the maximum temperature decreased as desired. For optimization of the two structural parameters, compression ratio, and stroke-bore ratio, it is necessary to decrease the stroke-bore ratio while increasing the compression ratio. The results obtained with the numerical study using the created model are guiding for engine designers.

Thermal Oxidative Stability of Biodiesel/Petrodiesel Blends by Pressurized Differential Scanning Calorimetry and Its Calculated Cetane Index

Diesel fuel mixtures with high concentrations of biodiesel have been investigated to analyze the technical feasibility of their use in diesel cycle engines regarding thermal and oxidative properties. The results of combined techniques of oxidative stability, high Pressurized Differential Scanning Calorimetry (P-DSC), Calculated Cetane Index (CCI), and calorific power were used to verify the effect of the thermal-oxidative stability as a function of the percentage of biodiesel in the mixtures. The obtained results evidenced that the thermal and oxidative stability decreased with the addition of biodiesel from 50 to 5% v/v. Low stability fuels require rapid use as the oxidation compounds degrade the product and impair vehicle performance, as well as lead to corrosion and clogging problems in various mechanical systems.

Substantiation of methods for determination of the effectiveness of the use of alternative fuels in automotive diesel engines

The subject of the research is to determine the parameters of the operating cycle of a tractor diesel engine when it is running on a mixed fuel, consisting of diesel fuel and rapeseed oil. The main goal of this work is to determine the efficiency of using alternative fuels in automotive diesel engines. In order to determine the dependences of the parameters of the operating cycle, the theoretical and experimental studies of a tractor diesel engine were carried out on the following compositions of mixed fuel: with a rapeseed oil content of 20%, 55% and 80%, as well as pure diesel fuel. As a result of the research, the following was obtained: a nomogram for determining the value of the decrease in the ratio of the indicator efficiency to the excess air ratio, the dependence of the ratio of the indicator efficiency to the excess air ratio on the excess air ratio for different compositions of mixed fuel, diesel engine crankshaft rotational speed, load at 1800 min-1 and 1400 min-1. It was experimentally established that an increase in the proportion of rapeseed oil in mixed fuel from 0 to 80%, the speed from 1400 to 2000 min-1 and the excess air ratio from 1.18 ... 1.22 to 4.32 ... 5.61 led to a decrease in the indicator efficiency from 0.46 to 0.35, and the ratio decreased from 0.30 to 0.08, an increase in the load from 0.2 to 1.2 MPa, at 1800 min-1, and 1400 min-1, and the excess air ratio from 1.17 ... 1.68 to 3.53 ... 3.60 led to a decrease in the indicator efficiency from 0.44 ... 0.40 to 0.28 ... 0.22, and the ratio from 0.34 ... 0.25 to 0 , 10 0.09, respectively. A 4.5% reduction in the ratio is theoretically calculated when the diesel engine runs on a mixed fuel containing 80% rapeseed oil as compared to pure diesel fuel, and this reduction by 4.1% has been experimentally confirmed. The convergence of the calculated value of the decrease in the ratio with the experimental data was 91.11%. In this regard, the well-known statement about the equality of the input of heat with fuel requires clarification.