scholarly journals Possibilities of using water-fuel emulsion in order to extend the diesel operating range and improvement of fuel supply processes

Author(s):  
А.Ю. Чистяков ◽  
Г.Б. Горелик ◽  
О.Н. Мозолев

В статье представлены результаты математического моделирования процессов топливоподачи судового дизеля при работе по винтовой характеристике при использовании дизельного топлива и водотопливной эмульсии с водосодержанием 30% в качестве аль­тернативного топлива. В результате исследования выявлены особенности процессов топливоподачи и влия­ние альтернативного топлива на рабочие характеристики впрыскивания серийной топлив­ной аппаратуры при работе на номинальном и частичных режимах. При оценке качества работы топливной аппаратуры учитывались: изменение характеристики подачи топлива; особенности распыливания топлива в начальной и конечной фа­зах впрыскивания; повышение стабильности последовательных циклов впрыскивания за счет увеличения активного хода плунжера; колебания остаточного давления в трубопро­воде высокого давления при последовательных циклах впрыскивания. При применении водотопливной эмульсии возможно существенное повышение каче­ства работы судового дизеля, расширение диапазона стабильных подач серийной топлив­ной аппаратуры как за счет возможности снижения скоростных режимов при малых подачах топлива, так и обеспечения форсированных подач топлива вследствие отсутствия повторных впрыскива­ний. The article presents the results of the mathematical modeling of marine diesel’s fuel supply processes during the screw characteristic while using diesel fuel and water-fuel emulsion with 30% water content as alternative fuel. As a result of the research, the features of the fuel supply processes and the effect of alternative fuel on the serial fuel equipment injection characteristics during operation in nominal and partial modes were identified. Considering the quality of fuel equipment operation the following features were taken into account, they are: changing fuel supply characteristics; features of fuel atomization in the initial and final phases of injection; increasing stability of the injection in sequential cycles by increasing plunger active stroke; residual pressure oscillations in the high pressure line during injection consecutive cycles. Using the water-fuel emulsion it is possible to significantly increase a quality of marine diesel engine operation, to extend the stable fuel supply range of the serial fuel equipment both from the possibility of speed modes reducing during fine fuel feed and providing forced fuel feed due to absence of repeating injections.

Author(s):  
Gennady Bentsianovich Gorelik ◽  
Oleg Nikolaevich Mozolev

The article presents the results of mathematical modeling of the fuel supply process of a marine diesel working on diesel fuel and water-fuel emulsion with a water content of 30% as an alternative fuel. There have been found the specific features of fuel supply and the influence of the alternative fuel on the injection characteristics of standard fuel supply equipment during operation in nominal and partial modes. In evaluating the quality of fuel equipment operation on a water-fuel emulsion there were taken into account the following facts: changing of the fuel supply characteristics; changing injection parameters; type of fuel spraying in the initial and final phases of injection and reduction of fuel proportion supplied during the needle landing period; greater stability of successive injection cycles by increasing the active stroke of the plunger by 25-30%; features of injection processes due to thermal explosion effect. The telegraph equation for the unsteady fuel motion in a high pressure pipeline is obtained. The operation parameters of a marine diesel engine 6CHSPN2A 18/22 (DRA-300) are considered in nominal mode according to the screw characteristic for diesel fuel and water-fuel emulsion: plunger stroke of the high-pressure fuel pump; maximum pressure of the steady state in the connecting pipe; average integral pressure of the steady state in the nozzle, which determines the quality of spraying, the speed of landing of the sprayer needle on the saddle; amount of fuel supplied during the needle landing period; cyclic fuel supply; duration of the main injection; stability criterion of fuel supply processes in successive cycles, etc. It has been inferred that water-fuel emulsions can take a separate place in the list of alternative fuels, which will contribute to improving the quality of traditional fuels, productive burnout of hydrocarbon, nitrogen-hydrogen mixture, spirit mixtures, etc. due to the rational introducing additives into fuel, increasing the reliability indicators of cylinder-piston parts, etc.


2021 ◽  
Vol 1 (50) ◽  
pp. 104-112
Author(s):  
KONIECZNY D ◽  
◽  
KRAWCZUK S ◽  

Thanks to the pressure of the Environmental Society, the priority of engine manufacturers is to reduce emissions of harmful substances into the atmosphere and reduce fuel consumption while constantly increasing engine performance. One way to overcome the aforementioned technical and social problems is to use alcohols, natural or synthetic, such as ethanol to power engines. The objectives of manufacturers of alternative fuels is to provide consumers with the opportunity to use their product without changing the parameters of the main units in their vehicles, therefore the stoichiometry of the combustion of fuel mixtures is important, since this parameter can affect the amount of fuel burned, the quality of exhaust gases and the power of the internal combustion engine. Combustion in a car engine is exothermic, which means that a side effect of this chemical reaction is heat released into the environment. The condition for starting the combustion process is the thermal coefficient – for spark ignition engines – a spark, and for diesel engines – heat during compression of the fuel-air mixture. From the above it follows that after the oxidation reaction in the exhaust gases there should be no residual fuel particles, which in turn is an image of stoichiometric combustion. Since the stoichiometric mixture is very difficult to achieve outside laboratory conditions, a distinction is made between a non-greasy mixture (too much oxidizing agent) and a saturated mixture (too little oxidizing agent), but always strive to reach λ = 1, which corresponds to a stoichiometric mixture. The heavy weight when working with ethanol fuel is the one that affects the operation of the engine and its components. Therefore, it is important to compare the physicochemical data of gasoline and ethanol, as well as mixed fuel – E85. The article deals with the stoichiometry of combustion of an alternative fuel - a mixture of gasoline and ethanol. The economic and environmental conditions that initiated the production of this type of fuel were taken into account, the fuel mixtures were divided according to the content of fuel and oxidants in the combustion chamber. Attention is drawn to the determination of the stoichiometric mixture, as well as to the lambda coefficient (λ), which helps to determine the type of mixture. The properties of gasoline (in the form of iso-octane) and ethanol are described in separate sections and each is compared. One chapter is devoted to the description of the E85 mixture used in Flexi Fuel Vehicles engines, the requirements for this fuel are determined by the Minister of Economy on the requirements for the quality of biofuels, and attention is also paid to the effect of the mixture on the operation of the engine and the content of chemical compounds in the exhaust using E85 biofuel. It has been established that ethanol fuel (in particular E100) is undoubtedly a step forward in terms of ecology, transport economics and the development of alternative fuels. However, its physicochemical properties cause many problems in engine operation. Despite the improvement in the net power generated by the engine, it should be remembered that for the current mechanical parts and their materials, this is a “problem” mixture that requires frequent and accurate diagnostics and calibration. KEY WORDS: STOICHIOMETRIC MIXTURE, COMBUSTION, MIXTURE OF GASOLINE AND ETHANOL, ALTERNATIVE FUEL, IMPROVEMENT OF THE PHYSICAL AND CHEMICAL PROCESSES OF THE ENGINE.


Author(s):  
S. R. Rakhmanov

In some cases, the processes of piercing or expanding pipe blanks involve the use of high-frequency active vibrations. However, due to insufficient knowledge, these processes are not widely used in the practice of seamless pipes production. In particular, the problems of increasing the efficiency of the processes of piercing or expanding a pipe blank at a piercing press using high-frequency vibrations are being solved without proper research and, as a rule, by experiments. The elaboration of modern technological processes for the production of seamless pipes using high-frequency vibrations is directly related to the choice of rational modes of metal deformation and the prediction resistance indicators of technological tools and the reliability of equipment operation. The creation of a mathematical model of the process of vibrating piercing (expansion) of an axisymmetric pipe blank at a piercing press of a pipe press facility is an actual task. A calculation scheme for the process of piercing a pipe plank has been elaborated. A dependence was obtained characterizing the speed of front of plastic deformation propagation on the speed of penetration of a vibrated axisymmetric mandrel into the pipe workpiece being pierced. The dynamic characteristics of the occurrence of wave phenomena in the metal being pierced under the influence of a vibrated tool have been determined, which significantly complements the previously known ideas about the stress-strain state of the metal in the deformation zone. The deformation fields in the zones of the disturbed region of the deformation zone were established, taking into account the high-frequency vibrations of the technological tool. It has been established that the choice of rational parameters (amplitude-frequency characteristics) of the vibration piercing process of a pipe blank results in significant increase in the efficiency of the process, the durability of the technological tool and the quality of the pierced blanks.


The analysis an influence of reflections from the underlying surface, atmospheric noise, the Earth’s surface, cosmic noise and signal attenuation of the signal the atmosphere, as well as the flight dynamics of the aircraft (AC) on the signal/noise ratio and, accordingly, on the accuracy of AC navigation definitions by using consumer equipment of the satellite radio navigation systems. The analysis an influence of reflections from the underlying surface on the equipment operation quality of the satellite radio navigation systems consumers is carried out by using the Beckman model, in accordance with the earth’s surface appears to consist of flat faces with an arbitrary slope. It is noted that reflections from the underlying surface have a greater effect on the quality of functioning of the consumer equipment of the satellite radio navigation systems in the tracking signal mode than in the detection mode. In this case, the influence of reflections increases with decreasing flight altitude and an increase in the angle of heel of the AC in the direction of the navigation spacecraft.


2020 ◽  
pp. 12-18
Author(s):  
F.A. Urazbahtin ◽  
A.YU. Urazbahtina

A multifactor mathematical model of the welding process of products from aluminum-magnesium alloys, consisting of 71 indicators that assess the quality of the weld, the welding process, costs, equipment operation and quality of the welded material. The model can be used to control and optimize the welding process of products from aluminum-magnesium alloys. Keywords welding, products, aluminum-magnesium alloy, indicators, process parameters, welding equipment, welding materials, electrode sharpening, lining [email protected]


2008 ◽  
Vol 45 (04) ◽  
pp. 191-193
Author(s):  
Wei Hai-jun ◽  
Wang Guo-you ◽  
Wang Xiao-rui

The purpose of this paper is to study the applicability of thermal processed fuel oil (hereafter called waste plastic disposal, or WPD) of diesel engines using low-quality fuel oil. In the experiment, stability of engine operation and components of exhaust gas, such as NOx and COx, were inspected from basic and applicable points of view. This paper illustrates a new test and result of WPD oil applied to marine diesel engines. In recent years, efforts have to be made to develop an advanced technique for recycling waste plastics in order to use scrapped plastics as fuel for diesel engines. It is very important and necessary for us to cope with the increasing calorific value and to satisfy the growing need of environment protection. The experimental fuel oil is obtained by a mixing of diesel oil, WPD, and water.


Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2995 ◽  
Author(s):  
Łukasz Warguła ◽  
Mateusz Kukla ◽  
Piotr Krawiec ◽  
Bartosz Wieczorek

Alternative fuel within the meaning of Directive 2014/94/EU is, among others, LPG (liquefied petroleum gas), characterized by a lower purchase cost and lower emissions of toxic exhaust compounds in comparison to the combustion of classic gasoline. In wood chippers, intended for chopping branches, with low-power internal combustion engines that meet the emission standards in force in 2019 in the European Union, in accordance with Regulation 2016/1628/EU, carburetor fuel supply systems are commonly used. Innovative trends in the development of these drives are: electronic fuel injection, systems supporting the adaptation of the working elements to the conditions of use and the use of alternative fuels. The first two solutions significantly affect the cost of purchasing a power unit or modernizing it. The authors of this article indicate, as a beneficial alternative, a cheap (EUR 105) possibility of modernizing the carburetor fuel supply system. It is based on a modification that will allow for the use of LPG instead of gasoline to drive the working system of the wood chipper. This article presents the results of tests on the fuel consumption of a wood chipper powered with gasoline (3.04 L h−1) and LPG (3.65 L h−1) during continuous chipping. The cost of an hour of chipping related to fuel consumption was determined, which was equal to 3.89 € h−1 while using gasoline, and 2.19 € h−1 when using LPG. The mass flow rate (0.66 t h−1) and volumetric flow rate (3.5 m3 h−1) of a wood chipper powered by a low-power (9.5 kW) internal combustion engine with spark ignition were determined. In addition, we determined the cost of producing 1 m3 of biomass from chipping freshly cut oak branches (Quercus robur L. Sp. Pl. 996 1753) with a maximum diameter of 80 mm and a humidity of 25%. The branches were selected earlier in such a way that their dimensions as as similar as possible. This amounted to EUR 1.11 for a gasoline-powered drive and EUR 0.63 for a LPG powered one. The benefits of using an alternative fuel supply system, the installation of which increases the cost of the machine by 8.4%, have been confirmed.


Author(s):  
G. Papalambrou ◽  
N. P. Kyrtatos

This paper addresses the reduction of smoke emissions and improvement of load acceptance in a turbocharged marine diesel engine, during transient operation involving rapid load increases. Model Predictive Control (MPC) provided the optimal quantity of injected air in the engine while minimizing smoke density (opacity), with constraint not to exceed a limit in intake manifold pressure, in order to avoid surge in the compressor. System identification methods were used to determine control models at various operating points of the engine. Transient response experiments were performed on a full-scale marine diesel test engine on a transient test bed, using real-time MPC configuration. Results comparing the opacity under air injection model predictive control with the standard engine operation without air injection, during the same transient, show reduction in opacity level while avoiding surge.


2013 ◽  
Vol 465-466 ◽  
pp. 302-307 ◽  
Author(s):  
Mohamad Farid Sies ◽  
Norrizal Mustaffa ◽  
Hanis Zakaria ◽  
Hamidon bin Salleh ◽  
Bukhari Manshoor ◽  
...  

Today, global warming is the biggest issues due the increasing of emissions from diesel fuel in transportation and manufacturing sectors [1-. The solution for this issue is by using Biodiesel fuel as alternative fuel in both sectors. Malaysia government has introduced the Biodiesel (B5) in the diesel engine for transportations [3]. Biodiesel fuel (BDF) in alternative fuel and renewable energy but it has low quality of fuel and can reduce the performance compared to the diesel fuel (DF)[4-6].


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