Comparative studies of the biodiesel fuel jet development dynamics in common rail and conventional design fuel systems

The results of comparative diesel and biodiesel (Rapeseed oil Methyl Ester (RME) and Rapeseed Oil (RO)) fuel jet structure studies by optical scanning method are presented. There is an interrelation between the dynamics of fuel jet development by the Common Rail (CR) with single-phase injection and Conventional Design System (CDS) and the parameters of mixture formation, which are typical for transferring the operation of the Diesel Engine (DE) from mineral diesel to RME and RO. The structure of the Diesel Fuel (DF) jet is significantly more heterogeneous by the size and number of droplets in CDS in comparison with CR. From the moment of the injection the presence of zones less saturated with fuel contributes to a relatively short induction period – 5° ca. compared to 11…12° ca. in the CR system. Using RME in the CR system in comparison with DF, increases the heterogeneity of the fuel jet, thereby causing a shorter (by 1…2° ca.) induction period in the whole investigated range of injection pressures of 60…160 MPa. The injection of a non-heated RO is accompanied by the shape and structure fluctuations of the fuel jet. RO heating to 65 °C stabilizes the structure of the jet and increases the share of less saturated zones. Promising way of use for the optical scanning method in the mathematical modelling of the DE working process is proposed

The influence of the fuel spray structure and dynamics of its formation on surface combustion of biofuels in diesel engines

The paper presents the results of the experimental investigation of the structure of the fuel, rapeseed oil and diesel fuel sprays obtained by analysing their optical density. The results are obtained by investigating a conventionally designed fuel supply system and a high-pressure common rail system. The experimental data on the velocity and length of fuel sprays are given. The study has shown that when high pressure fuel supply systems are used, the fuel spray is increased by about three times, while its area is increased up to 50% and homogeneity is also higher. As a result, selfignition delay time is reduced and the combustion process is intensified. The methods, taking into consideration the specific character of using the alternative types of fuel and high pressure systems, which have been tested in the experimental conditions, are suggested for calculating the time of self-ignition delay. The applied methods allow us to reduce the error of determining self-ignition delay time up to five percent. Based on the calculated data, the factors limiting the ignition of the sprayed fuel have been defined. First published online: 27 Jul 201

Mathematical model of combined parametrical analysis of indicator process and thermal loading on the Diesel engine piston

In the publication the methodical aspects of a mathematical model of the combined parametrical analysis of an indicator process and thermal loading on the diesel engine piston have been considered. A thermodynamic model of a diesel engine cycle is developed. The executed development is intended for use during researches and on the initial stages of design work. Its realization for high revolution diesel engines of perspective type CHN15/15 allowed to choose rational variants for the organization of an indicator process and to prove power ranges of application for not cooled and created cooled oil welded pistons

Improvement of the parameters of maitenance of medium speed Diesels applying the motor methods

The problem of the improvement of parameters of maintenance of medium speed diesel engines is described in the publication. The most rational way of solving this problem is the performing of calculational research by using modern programs of mathematical modelling. At the initial stage of the research the approbation of interapplication of computer programs with a different level of elaboration for the optimisation of the main indexes of medium speed diesel engines (fuel economy, reliability, emission of harmful components in exhaust gases) is performed. The investigated efficiency of separate motor methods was applied for diesel engines 6VDS 48/42 AL-2 which are widely spread in the fleet of Lithuania. For the performance of further investigations the indirect criterion which estimates the phase of kinetic combustion and emission of nitric oxides is offered

Research of usage of RRME and alcohol biofuel mixture in diesel engine

The paper provides the results of an integrated research of the energy, environmental performance and traction indicators and the characteristics of fuel feed and performance of A41, 2F511, VALMET 320 DMG and Audi 1Z highspeed, direct-injection diesel engines when converting their operation from mineral diesel D to the fatty acid esters (RRME and RRBE) and alcohol biodiesel mixtures. The researches are carried out in cooperation of the Lithuanian and Polish partners within the framework of joint scientific projects under EUREKA international scientific program „E!4018 CAMELINA-BIOFUEL”. In the light of the new EU initiatives („White Paper” 2011), 30% optimum part of RRME bio-component in the mixture with D (B30) is validated for practical use. The characteristics of fuel supply and heat generation in a diesel cylinder are under investigation; an explanation of a significant reduction in the harmful component emission (EG) and 2 to 4% increase in the fuel efficiency in case of use of B30 and B10 biodiesels is offered. The presence of the ethanol alcohol component 9E) in D-RME-E and RME-E biofuel mixtures resulted in reduction of CO and NOx emission by 10 to 12% and EG smokiness - by 20% per each 10% increase of E part. The indicated efficiency of performance was increased by 2-2.5%. The indicators of cyclic instability did not exceed the corresponding indicators in diesel operation on D. It is established that the motor properties of tested B30 and B50 biofuels based on butanol and rapeseed oil butyl ester RBE are similar to RME biodiesels and have important advantages over them: the complete solubility of alcohol component and the possibility of B30 (D-RBE) use at ambient temperature up to -30 centigrade. The motor characteristics of the second-generation biodiesels produced from the non-food raw material (Camelina Sativa oil methyl esters) are highly competitive with and even exceed by separate indicators the similar indicators of certified RME biodiesels. It is demonstrated that the conversion of diesels, including the automobile diesels with EGR electronic system, to operation on D-RRME (RME, CSME) biodiesels does not require the change of regulation characteristics of the fuel-feed system. The test of the oxidation stability of D-RME and D-CSME biodiesels performed under operating conditions on S. Lebedevas, G. Lebedeva, J. Žaglinskis VALMET 320 DMG marine diesel proved the stability of the motor, energy, and environmental performance indicators for 7-8 months' biodiesel storage without the addition of antioxidant and for 13-14 months' storage - with the addition of Ionol BS200 antioxidant

The method of simultaneous parametric analysis of the in-cylinder processes and thermal load on diesel piston units

The paper describes the basic methodological principles and the results of development and practical application of simultaneous complex parametric analysis of the in-cylinder processes and thermal load on cylinder piston unit in diesel engines. The application of the suggested method to research and conceptualize engine design allows us to choose an optimal combination of the cylinder-piston unit parameters and diesel engine control. As a result, an admissible level of thermal stress in the most heavily loaded parts of cylinder-piston unit and low fuel consumption of diesel engines are achieved. A limited number of factors determining perfect in-cylinder processes make this method easy to visualise as well as providing it with a clear physical meaning of graphically presented results, not restricting the analysis to the design parameters of engine units. The method was practically used for upgrading high-speed diesel engines of the trademarks CHN 16.5/18.5, CHN 15/18, and CHN 15/15, to increase their power based on the average indicated pressure, and to reduce their fuel consumption and harmful environmental effects. In particular, a method implemented in diesel engines CHN 15/15 of the basic design with their power increased by 60-70%, the power of diesel CHN 16.5/18.5 was increased by 70-100%

Исследование влияния нагрузки на долговечность двигателей грузовых локомотивов

The publication reflects the research results of the rationalization of the rolling stock use of JSC LG Lithuanian railways to increase the reliability indicators of the freight diesel locomotive exploitation reliability. The comparative evaluation of the exploited freight diesel locomotive work duration, according to the technical documentation, by using comparative test results and indirect diesel reliability criteria approved in practice. An algorithm of work duration forecasting methodology has been created, as well as a programme complex of mathematic modelling. The differences of the results indicated in the experiment and modelled by computer do not exceed 5÷7%. The proposed and described methodology of the diesel locomotive exploitation load cycle dynamic indicator reduction, by the use of which the following is achieved: increase of the diesel work duration by 7÷10%, reduction of fuel consumption up to 10%, reduction of the load cycle dynamic indicators (increasing the fatigue stress of parts and units of the diesel) by 15÷20%.Статья отражает результаты исследований, связанных с рационализацией подвижного состава ОАО Литовские железные дороги для улучшения показателей надежности эксплуатации грузовых тепловозов. Сравнительная оценка длительности эксплуатационной работы грузового тепловоза в соответствии с технической документацией базируется на результатах сравнительных испытаний и косвенных критериев надежности дизелей, полученных в практике. Был предложен алгоритм прогнозирования продолжительности эксплуатационной работы, а также программный комплекс для математического моделирования. Различие результатов, полученных экспериментально и моделируемых с помощью компьютера, не превышает 5 ÷ 7%. Предложены и описаны методология снижения динамического индикатора эксплуатационного цикла нагрузки тепловоза, с помощью которого достигается следующее: увеличение продолжительности работы дизеля на 7 ÷ 10%, снижение расхода топлива до 10%, снижение динамических показателей цикла нагрузки (снижение усталостных напряжений деталей и узлов дизеля) 15 ÷ 20%

Presumptions of effective operation of diesel engines running on rme biodiesel. Research on kinetics of combustion of RME biodiesel

The results of experimental research on kinetics of fuel combustion of diesel engine A41are presented in the publication. The change of characteristics of indicated work (in-cylinder pressure and temperature, period of induction, heat release and heat release rate) and fuel injection (fuel injection pressure, fuel injection phases) was determined in diesel engine running on RME biodiesel being compared to diesel fuel. The results of researches were used to explain experimentally determined changes of operational and ecological characteristics of diesel engine running on RME biodiesel. In addition, the reliability of diesel engine A41 running on RME biodiesel was evaluated. The presumptions of effective operation of diesel engines running on RME biodiesel were formulated