Self-ignition Engines Research Articles

The criteria for qualifying fuels as a replacement fuels for internal combustion engines

The article presents the classification of motor fuels into conventional and unconventional. The concept of replacement fuels is formalized as fuels that can replace conventional petroleum fuels for spark ignition and self-ignition engines without any structural or regulatory changes. The criteria for qualification unconventional fuels as replacement fuels are presented. This article also introduces the results of empirical research conducted on a single-cylinder research engine powered by diesel fuel and rapeseed methyl esters (RME) in summer version and winter version. The engine was tested and the combustion phenomenon in the cylinder was analyzed. Very similar engine properties were observed for diesel fuel and rapeseed methyl esters (RME) in the summer version, while greater differences were found for rapeseed methyl esters (RME) with winter additives. In light of the empirical research and the physicochemical properties of the fuels, it is concluded that RME warrants consideration as replacement fuel for engines with self-ignition, especially in the case of biofuel in the summer version.

Operational Issues of Using Replacement Fuels to Power Internal Combustion Engines

The classification of engine fuels was systematised in the present study. The basic evaluation criterion included the type of raw material used for the production of motor fuel and the prevalence of its usage. There was a reason for the purposefulness of searching for new kinds of engine fuels not only for the sake of environmental protection but also for the rational use of natural resources. The concept of substitute fuels was methodically presented. The criteria for the qualification of substitute fuels for internal combustion engines were systematised. Using the example of fuels produced from bio-oils, tests were carried out to assess the prospects of considering bio-oil fuels as substitute ones for self-ignition engines. Accordingly, an analysis was, inter alia, conducted on the fuel combustion process in the cylinder of a test self-ignition engine. Based on the results obtained, the thesis was formulated that rapeseed methyl ester (RME) fuel can be considered a substitute fuel for modern self-ignition engines. There are no significant differences between the physicochemical properties between DF diesel fuel and B100 fuel apart from a significantly higher oxygen mass content in B100. The torque of an internal combustion engine is regularly higher for diesel fuel. The use of B100 fuel enables a measurable reduction in pollutant emissions. The working factor pressure in the cylinder is slightly lower when the engine is powered by B100. The relative heat release rate for B100 is slightly lower compared to DF diesel.

Method and a Device for Testing the Friction Force in Precision Pairs of Injection Apparatus of the Self-Ignition Engines

This article reviews the state of the knowledge and technology in the field of friction-loss measurements in internal combustion piston engines. The dependencies that describe the loss of energy in combustion engines and injection apparatus are presented. Currently, very little can be found in the literature on the study of frictional forces in injection apparatus, but mainly in the piston–cylinder group, so this work significantly fills that gap. The aim of this article is to construct a device and to develop a method for assessing the technical state of injector nozzles to minimize friction losses in internal combustion engines at the stages of evaluation, design, production and operation. This article presents a stand for determining the maximum friction forces due to gravity loading by water-jet control. This article also presents test results on the maximum friction force between a needle and a body of injector nozzles in piston combustion engines on a designed and purpose-built stand outside of the combustion engine. Various designs and injector nozzles are made from various types of alloy steel for marine and automotive piston internal combustion engines fueled with distillation or residual fuels, and are tested. The research concerned conventional elements for the injection apparatus as well as electronically controlled subsystems. Precision pairs of injection equipment are selected for the tests: new ones are employed after the storage period and operated in natural conditions. The elements dismantled from the internal combustion engines are tested in the presence of fuel or calibration oil of similar properties. The maximum static frictional forces under the hydrostatic loading are measured, alongside the parameters for the dynamic movement of the nozzle needles from bodies of the injector nozzle as time, speed, acceleration and dynamic force. The influence of the angular position of the needle in relation to the bodies of the precision pairs conventional internal combustion engines, the diametral clearance between the nozzle body and needle, and the surface conditions on the values of the maximum friction force are also presented. Errors in shape and position result in the uniqueness of the friction force at the mutual angular position of the needle in relation to the nozzle body, and the decrease in diametral clearance and deterioration of the surface state increase the friction losses. A model was elaborated of the influence of various factors on the value of the maximum friction force.

Hydro-treated vegetable oil as a potential biofuel for self-ignition engines

Hydro-treating vegetable oils or animal fats is an alternative process to esterification for the production of biodiesel. Hydro-treated products are also called renewable diesel fuels. Hydro-treated vegetable oils (HVO) do not have the harmful effects of FAME biodiesel such as increased NOₓ emissions, deposit formation, storage stability problems, faster aging of the engine oil or poor cold performance. HVO are straight chain paraffinic hydrocarbons which are free of aromatic hydrocarbons, oxygen and sulphur and have a high cetane number. In the article below, the authors conduct a comprehensive analysis and evaluation of the possibility of running compression-ignition engine on the hydro-treated vegetable oil, which is a second-generation biofuel. On its basis, the information on the assessment of emissions of selected toxic components of exhaust gases and pollutants of the injection system when the engine is powered with this type of fuel, was systematized. The article ends with conclusions from the conducted analyses.

Analysis of Exhaust Gas Content for Selected Biofuel-Powered Combustion Engines with Simultaneous Modification of Their Controllers

The use of renewable resources for powering self-ignition engines in European Union countries involves a high demand for renewable energy which is not accompanied by the development of its production infrastructure. The application of biofuel in vehicle powering is supposed to provide reductions in greenhouse gas emissions and an increase in the share of renewable energy resources in the total energy consumption. The study includes the analyses of power unit exhaust components, such as oxygen, carbon monoxide, nitric oxides, carbonizers, carbon dioxide and a quantity of exhaust particles contained in exhaust gases. Tests using an exhaust gas analyzer and a vapor analyzer were conducted. Three high-pressure engines, characterized by direct fuel injection, were tested. The vehicle computer software adjustments included increasing the fuel dose and the air load. Mixtures of diesel oil and fatty acid methyl esters were used in the tests. Based on the results, a statistical analysis was performed and an assessment model was developed to understand the functioning of the research objects fueled with these mixtures, with simultaneous software changes in the vehicle computers. On the basis of the conducted analysis, it was found that only 30% of fatty acid methyl ester additives to diesel oil reduced the performance parameters of the drive units.

Effect of Adding Emulsifier to Fuel on Work Efficiency and Gas Turbine Emissions

In an effort to reduce the emissivity of transport and energy, numerous studies are being carried out on the impact of the combustion of alternative fuels on the emission and operating parameters of propulsion and energy units. One of the observed trends is the use of emulsion fuels. The addition of an emulsifier to an emulsion fuel reduces the interfacial tension between two liquids, which allows obtaining an emulsion fuel with the expected stability. The research conducted on self-ignition engines and gas turbines (TG) does not give an unambiguous answer as to the influence of the use of fuel-water emulsion on CO emissions. One of the reasons for the discrepancy in the obtained results may be the type and amount of the emulsifier used in the emulsion fuel. Tests were carried out on the GTM-120 gas turbine to compare the operating parameters and emissions between the cases in which TG was supplied with three fuel mixtures—the standard fuel for TG (DF) and DF with 2% and 5% emulsifier addition. It was shown that the addition of 2% of the emulsifier to DF causes an increase in CO emission, with the remaining measured parameters unchanged. On the other hand, increasing the amount of emulsifier in DF to 5% reduces CO emissions to the level observed in the case in which DF was burned reduces NOx emissions and reduces the thermal efficiency of TG.

Optimization of Design and Technology of Injector Nozzles in Terms of Minimizing Energy Losses on Friction in Compression Ignition Engines

The operation of injection apparatus in self-ignition engines results from the design, manufacturing technology and wear and tear during operation. The technical state of the injector apparatus significantly affects the engine performance, fuel consumption, toxicity and smoke opacity of outlet gases. The most unreliable element of the injection apparatus is the injector nozzle, the quality of which depends on the quality of construction and production, operating conditions and the of the fuels used, etc. One of the design parameters of the injector nozzles, determining the technical state is the geometry of the nozzle holes. An attempt was made to optimize the selection of the dimensions and surface condition of the spray holes to significantly affect the flow properties of the injector nozzles and, consequently, to decide on the size and form of fuel dosed streams to individual cylinders of a self-ignition engine and the quality of fuel atomization. In work, a simulation model was developed, and the pressure losses and the mass fluid of the injected fuel were minimized for selected significant geometric features, taking into account the influence of operating conditions. With the use of Mathematica software, simulation optimization methods and methods based on evolutionary algorithms were elaborated.

Diagnosing the technical condition of modern diesel injectors using thermal infrared cameras

Fuel injectors are the most damage-sensitive component of the diesel fuel injection system in self-ignition engines. Therefore, an important issue is their diagnosis for the proper assessment of their wear condition. The paper presents a method involving the use of an image from a thermal imaging camera to assess the technical condition of injectors used in common rail injection systems. Four injectors, whose technical condition was known, were tested. Three of them were characterized by a common fault they had damaged control valve seats, while one of the injectors was fully functional. In order to precisely assess their technical condition, the injectors were tested on a test bench. While the injectors were working, the temperature of the body in the place of the control valve was measured at a constant time interval. The conducted research has shown that there is a relationship between the rate of temperature rise of the damaged injectors’ body and their maximum temperatures, and the injection dose expenditure and the overflow expenditure.

Analysis of selected performance parameters of a drive unit fueled by biocomponents

The most desirable effect of motorization development is obtainment of high performance power units. Ecological requirements, however, and exhaustibility of the earth natural resources limit the possibilities of self-ignition engines. The study presents analyses of power and torque of a self-ignition engine fueled with mixtures of diesel and fatty acid methyl esters. The tests show that application of a biocomponent additive to diesel fuel slightly reduces the value of power and torque of the tested vehicle. Moreover, as proven by other tests, application of such mixtures causes an increase in the number of components in the exhaust gases and emission of sound generated by a power unit. The study shows only some of the tests performed to reflect significant performance parameters of transport means.

Database and Knowledge about Essential Manufacturers of Marine Self-Ignition Engines

During scientificstudies on reciprocating self-ignition marine engines, varying data are often needed. Such data are often in various collections and obtaining some of these is very difficult. Therefore, as it was elaborated in the electronic database about the important marine reciprocating combustion engine producers for the needs of operating scientific investigations aiming at gathering the essential information and technical data in one set. This article also presents a reference to existing databases. Important and globally known companies, as well as their constant and variable data, were described. These data were obtained from various printed and virtual sources of information. These data were selected and compiled in the environment of the Microsoft Access computer program. The collected information was divided between main propulsion and auxiliary engines, containing data about manufacturers, types, and technical parameters of slow, medium, or high-speed combustion engines. This database is constantly updated and rebuilt according to the constructions and changes on the engine production market as the result of economic and ecological functions. It is a relative type database, which contains information about technical data of combustion engines. Marine combustion engines are usually operated for dozens of years after they have been produced, whereas producers merge, change their names, or stop existing. Therefore, a digital-knowledge-management platform was developed in the virtual space in which information on scientific and technical resources was integrated of competing manufacturers with the option of introducing updates.

A New Method of Identifying the Limit Condition of Injection Pump Wear in Self-Ignition Engines

The quality or reliability of diagnostics is understood as obtaining the most likely diagnosis, and finding possible causes leading to incorrect operation of the system. In real engine running conditions it is often very difficult. Dependable methods providing the most reliable diagnoses have not been developed yet. It becomes more and more important to identify the limit state in condition monitoring—the state that should not be exceeded because continued operation of such a machine is not advisable for technical, economic, or operational safety reasons. The authors have implemented a method using acoustic emission signal analysis for the identification of the injection pump limit state in a working engine. The use of the cross gain function allows one to reliably diagnose limit conditions related to the wear of the precision pair in injection pumps of running engines, working as energy transmission systems on ships and in land-based power stations. The paper draws the results for two different marine diesel engines: two-stroke (by MAN B&W type 7S80MC-C) and four-stroke (by Wartsila type SW 380). The experiment results obtained indicate that the use of the cross gain function allows us to determine the limit condition for a various type of injection pump.

Environmental assessment of the exploitation of diesel engines powered by biofuels

Many factors, such as climate change and the associated risk of increasing the average temperature on the globe, energy security and the finishing of fossil fuel deposits have caused other renewable energy sources to be sought. Transport, as a branch of industry largely responsible for air pollution and greenhouse gas emissions in large cities, requires the necessary changes in the way vehicles are powered. Until now, the fuels available at petrol stations use admixtures of first generation biofuels, such as bioethanol, as a 5% additive to motor gasolines and biodiesel (FAME) as a 7% additive to diesel oil. The article presents the idea of biorefinery installations, specifies the spectrum of substrates of the second and advanced generations, which may be a biorefinery input, including waste oils that can be used to produce hydrogenated HVO vegetable oils and other high-value products. The paper presents he existing biorefinery plant in Venice resulting from the transformation of a conventional oil refinery in which HVO fuel is produced. The article also presents the parameters of this new biofuel and compared them with the parameters of other fuels used to power self-ignition engines, such as FAME and diesel, along with discussing the prospects for HVO fuel development in Europe.

Effect of the temperature of waste cooking oil methyl esters on the value of nitrogen oxides emission from the self-ignition engine

Combustion of diesel oil and liquid biofuels in self-ignition engines is related to the emission of harmful gases to the atmosphere (i.e. nitrogen, carbon or sulfur oxides). These compounds, emitted in significant quantities, pose a threat to human life and health, as well as to the natural environment. The goal of our research was to investigate the influence of temperature of the waste cooking oil methyl ester on the nitrogen oxides emission in the self-ignition engine. This is to help determine if the use of biofuel thermal activation can be used to reduce nitrogen oxides emissions. Experiments carried out on the test bench in relation to harmful nitrogen compounds (NOx). The emission of exhaust gases from a diesel engine fed with methyl esters of the cooking oil was measured. The measurements were made in accordance with ISO 8178-4. From the obtained test results it can be concluded that it is worth equipping the engine with installation for preheating the fuel before its injection, but the optimal value of fuel temperature reducing emissions is at least 70°C.

The Impact of Powering an Engine with Fuels from Renewable Energy Sources including its Software Modification on a Drive Unit Performance Parameters

The application of fuels from renewable energy sources for combustion engine powering involves a great demand for this kind of energy while its production infrastructure remains underdeveloped. The use of this kind of fuel is supposed to reduce the emission of greenhouse gases and the depletion of natural resources and to increase the share of renewable energy sources in total energy consumption and thus support sustainable development in Europe. This study presents the results of research on selected performance parameters of transport by internal combustion engines including: power, torque, the emission of sound generated by the engine, the content of exhaust components (oxygen O2, carbon monoxide CO, carbon dioxide CO2, nitrogen dioxide NO2), and the content of particulate matter (PM) in exhaust emission. Three self-ignition engines were tested. The fuel injection controllers of the tested internal combustion engines were additionally adjusted by increasing the fuel dose and the load of air. The material used in the tests were mixtures of diesel oil and fatty acid methyl esters of different concentration. A statistical analysis was performed based of the results. The purpose of the work was to develop a resulting model for assessing the operation of engines fueled with biofuel and diesel mixtures while changing the vehicle’s computer software. A computer simulation algorithm was also developed for the needs of the tests which was used to prognose the state of the test results for variable input parameters.

Evaluation of the suitability of synthetic polymer fuels in self-ignition engines

The article presents a method for determining the quality of spraying a mixture of oil and synthetic fuels obtained from the pro-cessing of polymer materials. Laboratory tests of physical parameters of such a mixture were carried out, which made it possible to determine the limit values for the volume fraction of synthetic fuels. The method of determining the suitability of this type of fuel takes into account the criterion numbers Re and Oh, which include physical parameters such as viscosity, density, and surface tension. The experimental part concerning the distribution of droplets of injected fuel and determination of Sauter Mean Diameter using laser diffrac-tion confirmed the usefulness of the developed method for the assessment of the possibility of using a mixture of petroleum-based and synthetic fuels in self-ignition engines.

A Concept of Determining the Relation between Load and Wear of Tribological Systems of Ship Main Selfignition Engines by Using Probabilistic Approach

Abstract This paper presents a proposal of simultaneous consideration of load and wear associated with it , of tribological systems of ship main engines (intended for ship propulsion) . Based on results of investigations it was assumed that both the load Q (i.e. a cause of wear ) and the wear Z (i.e. an effect of load occurrence) considered in a given time t (0 ≤ t ≤ tn) are random variables Qt and Zt ,respectively. There was characterized operational principle of ship main engines in definite external conditions (WZ) as well as consequences of excessive load of engines. Three hypotheses highlighting relations existing between load and wear of the above mentioned systems, have been proposed. The first of them deals with explanation of stochastic relation between load and wear, the second highlights why it is possible to assume that the load Qt and the wear Zt are positively correlated , and the third - why it is possible to assume that coefficient of correlation between Qt and Zt may be taken close to one.

The results of using of preliminary fuel treatment of water-fuel mixture in self-ignition engines

The paper discusses of implementing preliminary fuel treatment that take place in the fuel injector. Preliminary treatment results of mixture diesel oil fuel with water (up to 2,5%) in the direct injection diesel engines show the best ecological and economic results comparison of standard factory-made fuel equipments.

Effects of changes of injection timing on selected parameters of combustion process in a diesel engine fuelled with fuels of different properties

The internal combustion engine is and for many years will be the very important source of drive for many machines and vehicles. That’s why research and development centres are still researching to improve the design of it. The dominant feature among these studies is the evaluation of combustion process, which can be shaped according to different rules and various parameters. Through this article, the Authors join the discussion on the assessment of changes in selected parameters of combustion process caused by changes in injection timing of different fuels. The considerations were narrowed down to self-ignition engines with their representative VW 1.9TDI PD, which was subjected to laboratory tests. When making changes in injection timing, the following parameters were evaluated: excess air ratio, pressure in combustion chamber, heat of fuel dose and the related work of a single thermodynamic cycle. The first part of the article specifies the requirements for fuels and shaping the fuel stream in order to obtain the highest efficiency. The practical part contains the results of chemical tests of two fuels with different properties and laboratory tests that allowed to carry out cycle indicators for the selected load of tested engine. By identifying factors of injection timing, it was possible to determine the most favourable values of useful work of a single cycle, in relation to heat of fuel dose expressed in the values of fuel conversion efficiency.

DME Use in Self-Ignition Engines Equipped with Common Rail Injection Systems

Technological progress observed in combustion engine constructions is determined mostly by increasing ecological requirements. There is a tendency to make modern engines less harmful to the environment and characterized by the smallest possible fuel consumption. In case of self-ignition (SI) engines fuel injection strategy has the largest impact on defining those parameters. It is largely dependent on the fuel system used. In order to decrease the industry’s environmental burden, research is conducted to limit the use of crude oil, which is a non-renewable resource, by using alternative fuels produced of renewable resources. One of such fuels is dimethyl ether (DME) which, thanks to properties similar to the conventional fuel, is a good substitute in self-ignition engines. Moreover, it turns out that the use of dimethyl ether in combination with high-pressure fuel injection allows for reducing the emissions of some harmful compounds. DME combustion in self-ignition engines equipped with modern injection systems allows most of all for the reduction of particulate matter emission to such a level that the need to apply an additional particulate matter filter to meet the most up-to-date emission norms is eliminated.

The impact of various strategies on injection on the emission of the DME powered engine - a review

The dynamic development of the automotive industry makes the consumption of diesel oil grow rapidly. Due to the increasing ecological requirements, research is conducted that aims at the reduction of the negative influence of this branch of industry on the environ-ment. One line of research is the search for ecological fuels, such as dimethyl ether. The application of this fuel with a simultaneous use of modern injection systems allowing for injecting fuel under very high pressure enables emission reduction, as compared to diesel oil. It turns out that the combustion of DME in modern self-ignition engines results in al-most negligible emission of particulate matter, which used to be one of the main drawbacks of the engines fuelled conventionally.