scholarly journals Non-parametric models in the monitoring of engine performance and condition: Part 2: Non-intrusive estimation of diesel engine cylinder pressure and its use in fault detection

Author(s):  
F Gu ◽  
P. J. Jacob ◽  
A. D. Ball
Author(s):  
Dimitrios T. Hountalas ◽  
Spiridon Raptotasios ◽  
Antonis Antonopoulos ◽  
Stavros Daniolos ◽  
Iosif Dolaptzis ◽  
...  

Currently the most promising solution for marine propulsion is the two-stroke low-speed diesel engine. Start of Injection (SOI) is of significant importance for these engines due to its effect on firing pressure and specific fuel consumption. Therefore these engines are usually equipped with Variable Injection Timing (VIT) systems for variation of SOI with load. Proper operation of these systems is essential for both safe engine operation and performance since they are also used to control peak firing pressure. However, it is rather difficult to evaluate the operation of VIT system and determine the required rack settings for a specific SOI angle without using experimental techniques, which are extremely expensive and time consuming. For this reason in the present work it is examined the use of on-board monitoring and diagnosis techniques to overcome this difficulty. The application is conducted on a commercial vessel equipped with a two-stroke engine from which cylinder pressure measurements were acquired. From the processing of measurements acquired at various operating conditions it is determined the relation between VIT rack position and start of injection angle. This is used to evaluate the VIT system condition and determine the required settings to achieve the desired SOI angle. After VIT system tuning, new measurements were acquired from the processing of which results were derived for various operating parameters, i.e. brake power, specific fuel consumption, heat release rate, start of combustion etc. From the comparative evaluation of results before and after VIT adjustment it is revealed an improvement of specific fuel consumption while firing pressure remains within limits. It is thus revealed that the proposed method has the potential to overcome the disadvantages of purely experimental trial and error methods and that its use can result to fuel saving with minimum effort and time. To evaluate the corresponding effect on NOx emissions, as required by Marpol Annex-VI regulation a theoretical investigation is conducted using a multi-zone combustion model. Shop-test and NOx-file data are used to evaluate its ability to predict engine performance and NOx emissions before conducting the investigation. Moreover, the results derived from the on-board cylinder pressure measurements, after VIT system tuning, are used to evaluate the model’s ability to predict the effect of SOI variation on engine performance. Then the simulation model is applied to estimate the impact of SOI advance on NOx emissions. As revealed NOx emissions remain within limits despite the SOI variation (increase).


Transport ◽  
2014 ◽  
Vol 29 (4) ◽  
pp. 440-448 ◽  
Author(s):  
Tomas Mickevičius ◽  
Stasys Slavinskas ◽  
Slawomir Wierzbicki ◽  
Kamil Duda

This paper presents a comparative analysis of the diesel engine performance and emission characteristics, when operating on diesel fuel and various diesel-biodiesel (B10, B20, B40, B60) blends, at various loads and engine speeds. The experimental tests were performed on a four-stroke, four-cylinder, direct injection, naturally aspirated, 60 kW diesel engine D-243. The in-cylinder pressure data was analysed to determine the ignition delay, the Heat Release Rate (HRR), maximum in-cylinder pressure and maximum pressure gradients. The influence of diesel-biodiesel blends on the Brake Specific Fuel Consumption (bsfc) and exhaust emissions was also investigated. The bench test results showed that when the engine running on blends B60 at full engine load and rated speed, the autoignition delay was 13.5% longer, in comparison with mineral diesel. Maximum cylinder pressure decreased about 1–2% when the amount of Rapeseed Methyl Ester (RME) expanded in the diesel fuel when operating at full load and 1400 min–1 speed. At rated mode, the minimum bsfc increased, when operating on biofuel blends compared to mineral diesel. The maximum brake thermal efficiency sustained at the levels from 0.3% to 6.5% lower in comparison with mineral diesel operating at full (100%) load. When the engine was running at maximum torque mode using diesel – RME fuel blends B10, B20, B40 and B60 the total emissions of nitrogen oxides decreased. At full and moderate load, the emission of carbon monoxide significantly raised as the amount of RME in fuel increased.


2014 ◽  
Vol 660 ◽  
pp. 447-451
Author(s):  
Akasyah M. Kathri ◽  
Rizalman Mamat ◽  
Amir Aziz ◽  
Azri Alias ◽  
Nik Rosli Abdullah

The diesel engine is one of the most important engines for road vehicles. The engine nowadays operates with different kinds of alternative fuels, such as natural gas and biofuel. The aim of this article is to study the combustion process that occurs in an engine cylinder of a diesel engine when using biofuel. The one-dimensional numerical analysis using GT-Power software is used to simulate the commercial four-cylinder diesel engine. The engine operated at high engine load and speed. The ethanol fuel used in the simulation is derived from the conventional ethanol fuel properties. The analysis of simulations includes the cylinder pressure, combustion temperature and rate of heat release. The simulation results show that in-cylinder pressure and temperature for ethanol is higher than for diesel at any engine speed. However, the mass fraction of ethanol burned is similar to that of diesel. MFB only affects the engine speed.


2005 ◽  
Author(s):  
Olivier Grondin ◽  
Christophe Letellier ◽  
Jean Maquet ◽  
Luis Antonio Aguirre ◽  
Frédéric Dionnet

Author(s):  
A G Osborne

Demands for more power from the turbocharged diesel, without increase in bulk or weight, has led to an increase in levels of mean effective pressure by the application of high-pressure turbocharging. An investigation was conducted to determine engine performance under high b.m.e.p. conditions and this paper presents results of the experimental part of the research programme. Test work was carried out on a single-cylinder research engine equipped with an independent pressure-charging facility. Boost pressure ratios up to 6.2:1 were used with the geometric compression ratio reduced, in stages, to 8:1, to limit peak cylinder pressure. Power levels up to 35.4 bar b.m.e.p. were produced.


2021 ◽  
Vol 25 (Spec. issue 1) ◽  
pp. 101-110
Author(s):  
Erdinc Vural ◽  
Serkan Ozel ◽  
Salih Ozer

In this study, piston and valve surfaces of a Diesel engine to improve exhaust emis?sion and engine performance values, NiCr with bond coat and without bond coat with Cr2O3, Al2O3+13%TiO2, Cr2O3+25%Al2O3 coatings were coated using plasma spray method. By examining the micro-structures of the coating materials, it was observed that a good coating bond is formed. In this study, unlike other coating applications, two different and proportions of specific ceramic powders were coated on the combustion chamber elements, mounted on a Diesel engine, and their effects on engine performance and emissions were tested on the engine dynamometer. For this purpose, the internal combustion engine was operated at 1400, 1700, 2000, 2300, 2600, 2900, and 3200 rpm engine speeds and engine power, engine torque, in-cylinder pressure changes and heat release rate values were recorded. In this study, the that results were obtained by comparing thermal barrier coated engine with standard engine. An increase of 14.92% in maximum engine power, 12.35% in engine torque, 13% in-cylinder pressure, heat release rate by 4.5%, and brake thermal efficiency by 10.17% was detected, while brake specific fuel consumption decreased by 14.96%.


2020 ◽  
Vol 8 (10) ◽  
pp. 747
Author(s):  
Vladimir Pelić ◽  
Tomislav Mrakovčić ◽  
Vedran Medica-Viola ◽  
Marko Valčić

The energy efficiency and environmental friendliness of medium-speed marine diesel engines are to be improved through the application of various measures and technologies. Special attention will be paid to the reduction in NOx in order to comply with the conditions of the MARPOL Convention, Annex VI. The reduction in NOx emissions will be achieved by the application of primary and secondary measures. The primary measures relate to the process in the engine, while the secondary measures are based on the reduction in NOx emissions through the after-treatment of exhaust gases. Some primary measures such as exhaust gas recirculation, adding water to the fuel or injecting water into the cylinder give good results in reducing NOx emissions, but generally lead to an increase in fuel consumption. In contrast to the aforementioned methods, the use of an earlier inlet valve closure, referred to in the literature as the Miller process, not only reduces NOx emissions, but also increases the efficiency of the engine in conjunction with appropriate turbochargers. A previously developed numerical model to simulate diesel engine operation is used to analyse the effects of the Miller process on engine performance. Although the numerical model cannot completely replace experimental research, it is an effective tool for verifying the influence of various input parameters on engine performance. In this paper, the effect of an earlier closing of the intake valve and an increase in inlet manifold pressure on fuel consumption, pressure and temperature in the engine cylinder under steady-state conditions is analysed. The results obtained with the numerical model show the justification for using the Miller processes to reduce NOx emissions and fuel consumption.


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