scholarly journals Formation of a Flow-Line Technical Diesel Engine by the Method of Safety-Free Diagnostics

Author(s):  
Pavlo Chishkala ◽  
Denis Meshkov ◽  
Oduard Bozhko

The analysis of diagnostic methods of diesel engines is given. The principle of diagnostics by certain methods, parameters, by which the diagnostics of fuel injection equipment is conducted, as well as disadvantages of one or another method are considered. The main causes of derangements in the nodes of the fuel injection equipment of diesel engines are determined. The examples have proved that the direct diagnostics methods are the most effective in determining correlation dependencies, for example, indicating the workflow in a diesel cylinder. It is particularly established that the methods of technical diagnostics do not require dismantling of the fuel injection equipment and have proven themselves to be versatile and operative, allowing to comprehensively evaluate the condition of the diesel. The methods of non-separable diagnostic of the condition of a diesel engine are described in detail, the features of such indirect diagnostic methods as vibration, acoustic, indirect indicating by determining the voltage in the cylinder head studs, estimation of the wear rate of component parts with a metal content in engine oil, as well as diagnosing with uneven rate speed of the crankshaft. The vibro-acoustic diagnostic method of a diesel engine can be used to determine the technical condition of such elements as a diesel fuel injection pump , nozzles, and a fuel-priming pump. In addition, the characteristics of motor testers, highly specialized testers and auto scanners are given. A diagnostic feature using a computer auto scanner is that it allows evaluating the condition of nodes in a comprehensive manner, that is, taking into account the mutual influence of derangements on each other. It is noted that the methods that do not require disassembling can be considered the most effective, and the most accurate assessment of the technical condition of the diesel fuel system can be given using the diagnostic method according to the parameters of work processes.

Author(s):  
Tomi R. Krogerus ◽  
Mika P. Hyvönen ◽  
Kalevi J. Huhtala

Diesel engines are widely used due to their high reliability, high thermal efficiency, fuel availability, and low consumption. They are used to generate power, e.g., in passenger cars, ships, power plants, marine offshore platforms, and mining and construction machines. The engine is at heart of these applications, so keeping it in good working condition is vital. Recent technical and computational advances and environmental legislation have stimulated the development of more efficient and robust techniques for the diagnostics of diesel engines. The emphasis is on the diagnostics of faults under development and the causes of engine failure or reduced efficiency. Diesel engine fuel injection plays an important role in the development of the combustion in the engine cylinder. Arguably, the most influential component of the diesel engine is the fuel injection equipment; even minor faults can cause a major loss of efficiency of the combustion and an increase in engine emissions and noise. With increased sophistication (e.g., higher injection pressures) being required to meet continuously improving noise, exhaust smoke, and gaseous emission regulations, fuel injection equipment is becoming even more susceptible to failure. The injection systems have been shown to be the largest contributing factor in diesel engine failures. Extracting the health information of components in the fuel injection system is a very demanding task. Besides the very time-consuming nature of experimental investigations, direct measurements are also limited to selected observation points. Diesel engine faults normally do not occur in a short timeframe. The modeling of typical engine faults, particularly combustion related faults, in a controlled manner is thus vital for the development of diesel engine diagnostics and fault detection. Simulation models based on physical grounds can enlarge the number of studied variables and also obtain a better understanding of localized phenomena that affect the overall behavior of the system. This paper presents a survey of the analysis, modeling, and diagnostics of diesel fuel injection systems. Typical diesel fuel injection systems and their common faults are presented. The most relevant state of the art research articles on analysis and modeling of fluid injection systems as well as diagnostics techniques and measured signals describing the behavior of the system are reviewed and the results and findings are discussed. The increasing demand and effect of legislation related to diagnostics, especially on-board diagnostics (OBD), are discussed with reference to the future progress of this field.


Author(s):  

The necessity of adapting diesel engines to work on vegetable oils is justified. The possibility of using rapeseed oil and its mixtures with petroleum diesel fuel as motor fuels is considered. Experimental studies of fuel injection of small high-speed diesel engine type MD-6 (1 Ch 8,0/7,5)when using diesel oil and rapeseed oil and computational studies of auto-tractor diesel engine type D-245.12 (1 ChN 11/12,5), working on blends of petroleum diesel fuel and rapeseed oil. When switching autotractor diesel engine from diesel fuel to rapeseed oil in the full-fuel mode, the mass cycle fuel supply increased by 12 %, and in the small-size high-speed diesel engine – by about 27 %. From the point of view of the flow of the working process of these diesel engines, changes in other parameters of the fuel injection process are less significant. Keywords diesel engine; petroleum diesel fuel; vegetable oil; rapeseed oil; high pressure fuel pump; fuel injector; sprayer


2015 ◽  
Vol 236 ◽  
pp. 113-118
Author(s):  
Marcin Kluczyk ◽  
Andrzej Grządziela

The paper presents a model of dynamics of six-cylinder inline diesel engine executed in the Matlab software. The basic equations necessary to describe the forces acting during the engine operation was presented. Application of some simplifications allowed to present proposal of a mathematical model of the engine, which allows analysis of changes of forces in the crank-piston system, depending on the technical condition of the fuel system elements. Operational experience indicate that one of the most common cause of failure of the fuel system is reduced fuel charge supplied by a defective fuel injection pump. Calculations of gas forces had been replaced by the implementation into the model indication charts recorded from tests on a engine test stand. Simulation results were presented as a result of FFT spectra of modeled tangential forces.


Author(s):  
Vasyl Muzychuk ◽  
Vitaliy Komaha ◽  
Oleksii Tokarchuk ◽  
Oleksandr Kukharchuk

On the basis of the engineering practices of the last 3-4 decades, it is known, tested and proven that, while mathematical models provide reliable descriptions of processes, cycles or physical phenomena, in theoretical research the theory of small deviations is comprehensively preferable to any experiment on regulating characteristics. Considering the fact that all parameters and characteristics are sometimes interconnected by nonlinear dependences, it is impossible to distinguish the influence of a specific parameter on the sought-for value, and can be even hazardous if the determinant argument or its derivative has extreme values. The role of mathematic simulation to determine the residual lifetime of the fuel injection equipment of diesel engines was established. It was also noted that for a reliable description of the processes going on in the fuel injection equipment it is advisable to use the method of small deviations. The mathematical model is based on the known physical laws that describe the interdependence of the two groups of parameters: engine variables and performance parameters - both within the groups and between them. The transition of classical differential equations describing the processes of fuel supply and injection taking into account fuel leaks in precision pairs to the equations with small deviations of parameters is shown. An analysis of correlations between the parameters of injection, fuel supply and fuel leakage was carried out and the most influential parameters were found. The influence coefficients are found and correlations between the influence coefficients and the corresponding parameters are constructed. We used the correlations found to describe the influence of the technical condition of precision pairs on the engine performance indicators. The correlations between the change in injection patterns and small deviations of the parameters describing technical condition of precision pairs are also established.


Author(s):  
K. Subramanian ◽  
A. Kandaswamy ◽  
S. Mhahadevan

The two cylinder diesel engines are most demanding product in Indian market for power genset and tractor applications. But major task faced by engine manufacturers all over the world is to upgrade running engine designs with minimum and cost-effective modifications to meet the next level of emission norms. This saves the precious lead time and investments. In addition uncomplicated design has to be sustained as far as possible while improving emissions. Further the basic desires of the end user in off-road market are good response, transient performance, better low end torque, best fuel efficiency and smooth operation of the engine besides best in class reliability. Additional requirements needed to sustain the market with higher power to weight ratio and increased life of the engine. Henceforth turbocharging applications for off-road diesel engines are promising solution for enhancing rated power, low speed torque, transient performance, optimized fuel efficiency and engine downsizing. A trade-off is required to match some incompatible design issues like overall dimensions, cost, emissions control and performance in order to sustain the existing design. Future diesel engine emission standards will restrict vehicle emissions, particularly nitrogen oxides. In the present work, performance improvement for 1.7L, 2 cylinder in-line naturally aspirated diesel engine with mechanical fuel injection pump for off-road application is developed to contain all needs of the market. Design up-gradation of this engine for Tier IV is made with minimal design changes by optimal combinations of fuel injection equipment. This includes proper optimization of performance with improvements in nozzle geometry, change in injector end pressure. But due to the increased fuel flow rates for improving the engine performance as well as emission reduction, there is also a requirement for increased air flow. Henceforth in this study air flow rate is simulated and discussed for selection of turbocharger and intercooler. Further elaborate design and analysis study is also done on cooled exhaust gas recirculation system for exhaust gas cooling efficiency, Diesel Oxidation catalyst, Selective Catalytic Reduction /Lean NOx Trap substrate selection for reduced pressure drop and maximum retention time for exhaust gas to achieve Tier IV norms in turbocharged intercooled two cylinder engine.


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