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EN
In this paper, the results of modeling of the burning process in the piston engines whose working process is realized on the basis of various conceptual approaches are presented: in diesel with direct injection of the fuel; in a gas engine with spark ignition; and in a two-fuel engine (in the gas-diesel), where the mixture of natural gas and air ignites with the help of the fuse dose of the diesel fuel. The models of burning based on the different in-principle approaches are analyzed and used. Verification of the models is performed by a comparison of the results of modeling with the experimental diagrams. The specific values of the empirical coefficients, used in modeling of the burning proces in the engines under study, are determined. The practical recommendations on the choice of the burning model depending on the working process conception are given.
EN
The article discusses methods for determining top dead center, based on the analysis of pressure diagrams of a marine engine. The advantages and disadvantages of different methods are shown. Diagnostics of marine engines during operation and the selection of optimal operating conditions is based on the analysis of gas pressure diagrams, as well as fuel supply and gas distribution diagrams. As a result of the analysis of the pressure diagrams, the indicator engine power is calculated, which is further used in the management of engine operation modes, in the calculation of specific indicators, as well as in the calculation of energy efficiency coefficients of marine vessels according to International Maritime Organization recommendations. The influence of the accuracy of determining the position of the top dead center on the calculation of the mean indicated pressure and indicator power is shown. The authors considered a method for determining top dead center, based on the solution of the equation P’= 0, which provides the required accuracy in calculating the mean indicated pressure and indicator power of the engine during operation. It is shown that the method can be applicable in marine engine working process monitoring systems as an alternative to hardware methods for determining the top dead center.
EN
This paper presents the application of Fisher-Snedecor distribution F statistics to assess the significance of the influence of changes in the active cross-sectional area of the inlet air channel (Adol) flow in a diesel engine on the observed diagnostic parameter determined on the basis of measurements of the quick changing exhaust gas temperature in the outlet channel, which is the specific enthalpy of the exhaust gas stream within one engine operating cycle (hspal). A plan of experimental tests carried out on the laboratory stand of a single-cylinder Farymann Diesel type D10 laboratory engine was presented and the method of determination of F statistics values for the obtained measurement results was characterized. Representative results of calculations were presented and the strength of Adol input parameter influence on the determined diagnostic parameter hspal simplified physical model of the working process of a compression ignition engine as the object of diagnosis was evaluated. It is planned to further develop the experimental research program to determine the significance of the influence of changes in the values of selected parameters of the engine structure on other diagnostic measures determined from the exhaust gas temperature signal, i.e. the mean peak-to-peak value as well as the rate (intensity) of increase and decrease in its value for individual engine cycles.
EN
The article presents results of investigation on the combustion of a mixture of pyrolysis oil from tires and regular fuel in the internal combustion reciprocating piston engine. The tested fuel consisted of: diesel fuel and pyrolysis oil at amount of 10% by volume. The tests were carried out on a single-cylinder naturally aspirated compression-ignition engine. The engine was equipped with a common rail fuel injection system and an electronic control unit that allowed changing injection timing. A comparative analysis of pressure-volume charts for the reference fuel, which was diese fuel, and for a mixture of diesel with 10% addition of pyrolysis oil was carried out. Injector characteristics for the reference fuel and the mixture were determined. Engine efficiency for both fuels was also determined. Unrepeatability of the engine work cycles for the diesel fuel and the tested mixture was calculated. Finally, exhaust toxic emission was analyzed. It was found that the pyrolysis oil can be used as valuable additive to regular diesel fuel at amount up to 10%, however, toxic exhaust gases emission was increased.
EN
Vibration energy harvesting systems are using real ambient sources of vibration excitation. In our paper, we study the dynamical voltage response of the piezoelectric vibrational energy harvesting system (PVEHs) with a mechanical resonator possessing an amplitude limiter. The PVEHs consist of the cantilever beam with a piezoelectric patch. The proposed system was subjected to the inertial excitation from the engine suspension. Impacts of the beam resonator are useful to increase of system’s frequency transition band. The suitable simulations of the resonator and piezoelectric transducer are performed by using measured signal from the engine suspension. Voltage outputs of linear (without amplitude limiter) and nonlinear harvesters were compared indicating better efficiency of the nonlinear design.
EN
Despite the fact that more than a hundred years have passed since the first design of the compression ignition (CI) engine appeared, its optimal design has not yet been achieved. It is still the subject of constant modernisation in order to meet the new expectations of users in terms of its dynamics, economy, and, in recent months, also ecology. The most effective fulfillment of these requirements is achieved through new solutions of the fuel supply system and electronic control of injection and combustion processes. The publication includes the test results obtained on the basis of two engines. One of them is the single-cylinder CI engine AVL5402, and the other one – a threecylinder CI engine AD3.152. The first one is equipped with the Common Rail fuel supply system, electronically controlled with the selenoid injector. The second engine has a CAV distributor fuel injection pump and traditional, mechanical controlled injectors. The paper demonstrates how these two different structural systems for supplying and controlling engine parameters affect the selected indicators of the injection and combustion process. The influence of diesel fuel (DF) and rapeseed oil (RO) feeding the engine in both different injection and control systems on the unrepeatibility of the injection pressure on the maximum combustion pressures in the engine cylinder and, consequently, non-uniformity of the crankshaft rotational movement of the engine were also pointed out. The continuation of the research in this area seems to be expedient. They can be supplemented with statistical models of these phenomena. The results obtained in this way could be helpful in optimising the design of power supply systems and engine combustion chambers.
EN
The paper presents the methodology for designing the injection shaft drive for diesel engines with 2,3,4,6 and 8 cylinders as well as power from 2.5 to 52 kW per cylinder using the FEM method and experimental research. The pump is the original solution of the authors. The shaft is a basic part of the pump with a complex structure. In order to assess the state of stress in the shaft, the FEM analytical method was used and experimental tests were carried out, subjecting the shaft to torsional moment resulting from the transmitted power. Experimental studies confirmed the results of numerical calculations and the correctness of the adopted solution. The destructive tests were carried out to assess the maximum load capacity of the shaft, loading it with an increasing torque until visible plastic deformations occurred. This condition appeared at twice the moment (Ms = 602 Nm) in relation to the maximum predicted moment in operation (extreme operating conditions of the pump shaft). The theoretical studies confirmed very significant stress concentration (αk coefficient at the level of 2.63 or even 4.7), which may be the cause of fatigue cracks. It also determines the strength of the shaft and its torsional stiffness, which influences the proper functioning of the pump and ensures adequate fuel injection phases.
EN
In recent years, the opposed-piston engines have become increasingly popular in the automotive and aerospace industries. Therefore, it is necessary to conduct the research on this type of drive. The paper presents the simulation research of a two-stroke opposed-piston diesel engine designed for propulsion of light aircrafts. The influence of the change of the compression ratio on the selected engine performance was investigated (indicated mean effective pressure, peak firing temperature and pressure, specific fuel consumption, power consumed by the compressor). The AVL BOOST software was used to perform the simulation tests. A zero-dimensional engine model equipped with a mechanical compressor was developed. On the basis of the created model, a series of calculations was performed for the assumed values of the compression ratio for four engine operating points: take-off power, maximum continuous power and cruising power at two different altitudes. The obtained results were subjected to a comparative analysis and the most important conclusions connected with the influence of the change in the compression ratio on the achieved performance were presented.
EN
A combustion engine turbocharger works in most difficult conditions due to high temperatures of the fuels it is driven by, vibrations and high rotational speeds of its shaft up to 200 thousand rpm. In addition, under these conditions, there are difficulties with lubrication of the blade axes. Thus, the combustion engine turbocharger is exposed to the damages occurring during the engine operation process. The frequency of damages was determined on the basis of tests for a selected group of vehicles. The object of detailed author’s own research was the Audi 3.0 V6 TDI engine of the Audi A6 C6 car which cooperated with a Borg Warner turbocharger with a variable angle of turbine steering wheel blades. These positioners are also exposed to adverse conditions: mainly vibrations and high temperatures. They are subjected to frequent damages, which often affect the engine control parameters. An analysis of the positioner element damage as well as a group of testers to assess their technical condition was made. The evaluated testers were allowed only to determine the efficiency of the turbocharger, but without indicating its technical condition or its positioner separately. Consequently, the author’s own research methodology and the construction of a new tester for the electromechanical turbocharger adjuster was developed. The necessary tests for the vehicle mileage up to 350,000 km were carried out. The self-designed tester can also estimate the degree of electromechanical wear of the positioner in the engine supercharging system as well as the resistance of its movements resulting from the pollution of the VTG turbocharger mechanism with the turbine steering wheel positioner, with variable geometrical parameters.
EN
In this study, an experiment was conducted to examine the AVL research diesel engine using two kinds of waterdiesel (W-D) fuel microemulsions. These W-D mixtures contained 3.5 and 7.0% by volume (%, v/v) of distilled water dispersed in regular diesel fuel meeting the requirements of the EN590 standard. The engine was tested under the conditions of low, moderate and higher loads. This research was focused on the emission characteristics of nitrogen dioxide (NO2 ) and nitrogen monoxide (NO). Cumulative emission of NOx was also analyzed before being further discussed. The obtained results of this study showed that the addition of distilled water to the regular diesel fuel has a minor effect on the variation of the nitrogen oxides emission. It was confirmed that NO is the main component of NOx detected in the exhaust stream of the AVL engine fuelled with all tested fuels. It proves that the thermal mechanism of the nitrogen oxides formation was dominant in the combustion process. Moreover, it was found that the addition of water dispersed as microemulsion in diesel fuel had a minor effect on the reduction of the NOx emission.
EN
The paper reports a computer model for simulating dynamic responses in fuel rail of aircraft diesel engine. The fuel system was designed for use in a two-stroke compression-ignition engine with opposite pistons. The methodology of building a fuel system model in the AVL Hydsim program and the results of simulation studies were presented. Determination of dynamic phenomena in the fuel rail required the construction of a model of the entire supply system. It is a common rail system with a three-section positive displacement pump and electromagnetic fuel injectors. The system is also equipped with a PID regulator to maintain the present pressure in the fuel rail. For the purposes of the research, two structures of the fuel rail were developed. They differ in dimensions, spacing of the outlet ports and location of the high-pressure connection. The research allowed determining the interactions between the geometry of the fuel rail and the supply method with the fuel pressure and injector mass flow rate. This will optimise the design of the fuel rail for the three-cylinder engine power supply system.
EN
This paper investigated the impact of the exhaust gas recirculation on the concentration of selected harmful chemical compounds from the AVL 5402 research diesel engine powered with diesel fuel (DF) and compressed natural gas (CNG). The engine was operated in the dual fuel mode. It means that the engine was conventionally fuelled by regular diesel fuel and simultaneously by CNG dosed into the inlet pipe. The necessary tests were carried out for the mixtures containing 30, 50 and 70% of CNG (by energy content) in the total chemical energy delivered together with diesel fuel (DF) into the combustion chamber. The research was conducted for the stationary conditions of the engine operation at 1200 rpm and constant 1004 Joules of a fuel chemical energy delivered in each cycle into the combustion chamber. Under such conditions, the impact of the EGR rate changed in range of 0–50% on the emissions of selected unburned hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx) as well as particulate matter (PM), was evaluated. The obtained results confirmed that the EGR system is effective in the reduction of the NOx formation for all tested fuel mixtures. Nevertheless, it was found that the addition of CNG combusted in the diesel engine generates more harmful pollutants in comparison with diesel fuel. However, in some cases the concentration of NOx as well as PM was comparable or lower. It suggests that the combustion of CNG in diesels allows achieving environmental benefits. In this case, further optimization of the engine fuel supply system is necessary.
EN
The paper presents the research results of the AVL diesel engine powered with microemulsion fuels. In particular the emission of soot particles from the engine operated under stationary conditions was investigated. The necessary tests were carried out for two microemulsions containing 3.5 and 7% by volume of distilled water dispersed in diesel fuel with necessary surfactants/cosurfactants, i.e. Crillet-6/Span-20. Both tested microemulsions contained similar water micelles size distribution with average dimension of 18 nm. The results of the investigation confirmed that the combustion of tested water – fuel microemulsion in the AVL research engine reduces the emission of soot particles even by 50% in comparison with the diesel fuel.
PL
Wdrożenie w silnikach Diesla lokomotyw spalinowych systemów dwupaliwowych – olej napędowy / gaz ziemny, prowadzi do obniżenia emisji substancji szkodliwych w spalinach oraz oszczędności w związku z konkurencyjnymi cenami gazu ziemnego. Przedstawiono opis zespołów i urządzeń systemu dwupaliwowego wdrożonego na lokomotywie spalinowej serii S200 wraz z rysunkami ich zabudowy w pojeżdzie. Omówiono zagadnienia dotyczące układu sterowania, prób i badań lokomotywy, certyfikacji, infrastruktury tankowania gazu. Zaprezentowano wyniki badań stacjonarnych i ruchowych lokomotywy oraz uzyskane efekty.
EN
With 70% of all locomotives still being powered by diesel and most of the locomotives being older than 30 years, the railway industry must urgently seek environmentally friendlier and economically more attractive alternatives to diesel fuel. Dual-fuel systems once installed on diesel locomotives, allow substituting most diesel fuel with much cheaper and cleaner gas fuels – biogas, natural gas, and syngas – without the necessity for large capital investments. This article describes a case of dual-fuel conversion of a S200/CHME3 series diesel locomotive, introducing to the system specifics, certification procedure, gas refueling infrastructure, as well as outlining the main economic and technical results. The article concludes by outlining the dual-fuel perspectives in the Polish railway industry and estimates the economic and ecological benefits its implementation can bring.
EN
For internal combustion engines, many faults relating to the combustion process can occur, which affect the engine technical condition, its electrical equipment, the natural environment, etc. This article presents the results of the influence of the regulatory factor, which was the fuel dose (3 dose values), on selected parameters of the start-up process at constant settings of other control parameters (fuel injection advance angle and injection pressure). The tests of the start-up process were carried out on a fourstroke single-cylinder diesel engine. In this study, the results of the following electrical start-up parameters were analyzed: the maximum current consumed by the starter, difference of voltages on the battery before and after the start-up, voltage drop on the battery at the beginning of the start-up, average power of the starter, starter operation time, and the maximum pressure value in the first combustion cycle.
EN
The paper considers the issue of thermo-chemical recovery of engine’s waste heat and its further use for steam conversion of the associated gas for oil and gas floating units. The characteristics of the associated gas are presented, and problems of its application in dual-fuel medium-speed internal combustion engines are discussed. Various variants of combined diesel-gas turbine power plant with thermo-chemical heat recovery are analyzed. The heat of the gas turbine engine exhaust gas is utilized in a thermo-chemical reactor and a steam generator. The engines operate on synthesis gas, which is obtained as a result of steam conversion of the associated gas. Criteria for evaluating the effectiveness of the developed schemes are proposed. The results of mathematical modeling of processes in a 14.1 MW diesel-gas turbine power plant with waste heat recovery are presented. The effect of the steam/associated gas ratio on the efficiency criteria is analyzed. The obtained results indicate relatively high effectiveness of the scheme with separate high and low pressure thermo-chemical reactors for producing fuel gas for both gas turbine and internal combustion engines. The calculated efficiency of such a power plant for considered input parameters is 45.6%.
PL
„W jaki sposób mogę efektywniej korzystać z moich maszyn?” – to podstawowe pytanie nurtujące wszystkich właścicieli oraz użytkowników maszyn drogowych.
18
Content available remote Research and FEM analysis of the injection pump shaft for diesel engines
EN
The paper presents the methodology for designing the drive shaft of the injection pump for diesel engines with cylinder numbers of 2, 3, 4, 6 and power from 2,5 kW to 52 kW per cylinder using the finite element method (FEM) and experimental research. The pump is the original solution of the authors. The shaft is the basic part of the pump with a complex structure. In order to assess the state of stress in the shaft, the analytical FEM was used and experimental tests were carried out, subjecting the shaft to twisting with the design torque resulting from the transferred power. Experimental research confirmed the results of numerical calculations and the correctness of the adopted solution. In order to evaluate the maximum load capacity of the shaft, destructive tests were carried out, charging it with increasing torque until visible plastic deformations occurred. This condition occurred at a time twice as high as the maximum anticipated moment in operation.
PL
W pracy przedstawiono metodykę projektowania wału napędowego pompy wtryskowej do silników wysokoprężnych o liczbie cylindrów 2, 3, 4 i 6 oraz mocy od 7,5 do 57 kW na cylinder, z wykorzystaniem metody elementów skończonych (MES) i badań eksperymentalnych. Pompa jest oryginalnym rozwiązaniem autorów. Wał jest podstawową częścią pompy o złożonej strukturze. Do oceny stanu naprężenia w wale zastosowano metodę analityczną MES oraz przeprowadzono badania eksperymentalne, poddając wał skręcaniu momentem obliczeniowym wynikającym z przenoszonej mocy. Badania eksperymentalne potwierdziły wyniki obliczeń numerycznych i poprawność przyjętego rozwiązania. Aby ocenić maksymalną nośność wału, przeprowadzono badania niszczące, obciążając wał rosnącym momentem skręcającym do wystąpienia widocznych odkształceń plastycznych. Taki stan pojawił się przy momencie dwukrotnie większym w stosunku do maksymalnego momentu przewidywanego w eksploatacji.
19
Content available remote A review of the behavior of fuel drops in a fuel spray in the context of biofuels
EN
In addition to gasoline and diesel fuel, the biofuels HVO and FAME have been taken into wide use during the last decades. The properties of gasoline and diesel fuel and their effect on the combustion process have been studied for a long time, but studies on HVO and FAME are still are very much work-in-progress. Existing studies show that the use of biodiesels reduces the level of several exhaust gas emissions (like soot) in engine exhaust gases. At the same time, the reasons for the reduction of emission compounds remain unclear. The motivation behind determining drop size and behavior is to aid assessment of the quality of the air-fuel mixture with a view to explaining the reduction in soot emission when biodiesels are used. The aim of this review paper is to provide an overview of the behavior of fuel drops and their size in fuel injectors when using different biofuels by giving a theoretical background based on literature, on the basis of which the calculations give an opportunity to evaluate experimental results of the behavior of different biofuels in the fuel spray. This study compares four different fuel types according to the WAVE-RT model. In addition, the collision mechanisms of drops (reflexive and stretching separation) are presented and these shall be compared for the fuel types. The results show that during the use of biofuels, the drop size is somewhat larger compared to diesel fuel.
20
Content available remote Conversion of diesel engine to alternative bio-alcohol fuel
EN
Research has been carried out on feasibility of using biomethanol as a fuel in diesel engines converted for work on spirits, compared to usage of diesel fuel of petroleum origin. For realization of these tasks at Department of Automobile Transport in IFNTNG was converted for work on methanol automobile diesel engine of model XI7DTL OPEL. To convert the diesel engine to methanol compression strength of the engine was reduced to 14.1 by installing of additional gaskets under the head of cylinder block, an original microprocessor DIS ignition system of own design was installed, and engine management system was optimized. Experimental dependences of effective power and specific fuel consumption on the crankshaft rotational speed for the original diesel engine and converted for methanol diesel engine have been investigated. It is established that transferring diesel engine for work on methanol it is possible to achieve power indexes of original one. Analysis of exhaust gases during transferring of diesel engine to work on methanol shows that in all modes of engine there is a significant reduction in emissions of nitrogen oxides and carbon monoxide.
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