scholarly journals DEPENDENCY OF THE AUTOIGNITION DELAY, COMBUSTION AND EXHAUST EMISSIONS OF A DIESEL ENGINE ON THE CETANE NUMBER OF AVIATION-TURBINE JP-8 FUEL

2014 ◽  
Vol 46 (1) ◽  
pp. 23-39 ◽  
Author(s):  
Gvidonas Labeckas ◽  
Stasys Slavinskas ◽  
Valentina Vilutienė ◽  
Irena Kanapkienė

The article presents the bench test results of a fully instrumented, four cylinder, naturally aspirated, (60 kW) DI diesel engine running on the normal (class C) diesel fuel (DF) and aviation-turbine (JP-8) fuel. Analysis of changes in the autoignition delay, maximum in-cylinder pressure, performance efficiency of an engine and exhaust emissions caused by the variation of the cetane number of JP-8 fuel was provided. The series of engine tests were conducted running on the normal JP-8 fuel and JP-8 treated with 0.04vol%, 0.08vol%, 0.12vol%, 0.16vol%, and 0.24vol% of 2-ethylhexyl nitrate. Studies on operating characteristics of an engine were carried out for the fully loaded (100%) engine and the two ranges of speed, - 1400 rpm at which maximum torque occurs and rated 2200 rpm speed.Adding of 2-ethylhexyl nitrate to aviation-turbine fuel in the above proportions the cetane number (CN) of JP-8 fuel improved from 42.3 to 46.1, 47.6, 48.5, 49.4, and 49.8, respectively, enhancing ignition properties of the fuel to adapt it for using in ground-based military transport. The increase of CN from the reference value of 42.3 to optimum value of 48.5 suggested the brake specific fuel consumption lower 1.4%, both total unburned hydrocarbons (THCs) 7.5% and exhaust smoke 5.7% higher with almost unchangeable the NOx emissions behaviour and 11.9% lower CO emissions when running under a fully (100%) opened throttle at rated 2200 rpm speed. The brake thermal efficiency increased to maximum value of 0.309 (1.3%) for given operating conditions. Analysis of the results revealed that the improved cetane number can be considered as an effective but not the only measure to be applied for an intended use of JP-8 fuel in ground-based diesel engines.

2020 ◽  
Vol 15 ◽  

In this present study a theoretical investigation is used to examine the effect of different fuel cetane numbers (CNs) on reducing the ignition delay and exhaust emissions from diesel engine at certain operating conditions. The operating conditions for such diesel engine include compression ratios, engine speeds and intake pressures and temperatures. For this purpose, the fuels with 40 and 50 CN were tested in a four cycle, four cylinders direct injection (DI) diesel engine. Theoretical analyses were conducted for the standard injection pressures (150 bars); the exhaust emissions were tested at engine speeds from 4500 min-1 to 1000 min-1 at full engine load. The results showed that, at all operating conditions, the ignition delay decreases as the cetane number, compression ratio, engine speed, intake pressure and temperature are increased so that combustion efficiency is improved. Also the exhaust emissions NOX, SO2 and CO are reduced when the fuel CN is increased from 40 to 50 for the standard injection pressure (150 bars). Increases in engine torque and power output were observed when the CN is increased.


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.


Fuel ◽  
2019 ◽  
Vol 258 ◽  
pp. 116131 ◽  
Author(s):  
Yan Wu ◽  
Pan Wang ◽  
Sheikh Muhammad Farhan ◽  
Jing Yi ◽  
Lili Lei

2012 ◽  
Vol 614-615 ◽  
pp. 436-440
Author(s):  
Jia Yi Du ◽  
Hai Ling Li ◽  
Deng Pan Zhang ◽  
Yong Jia Lu

Based on Methanol and diesel special combustion mode, a control strategy of methanol/diesel dual fuel engine on turbocharged DI diesel engine was introduced according to different operation conditions. A method of judging engine load by measuring intake manifold pressure was put forward. Bicubic interpolation method was adopted to optimize the control MAP for ensuring the coincidence between look-up table data and actual conditions. The feasibility of the control strategy is verified by bench test. And the results of test show that the economic performance of this dual fuel engine got a considerable improvement.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Lyes Tarabet ◽  
Khaled Loubar ◽  
Mohand Said Lounici ◽  
Samir Hanchi ◽  
Mohand Tazerout

Nowadays, the increasing oil consumption throughout the world induces crucial economical, security, and environmental problems. As a result, intensive researches are undertaken to find appropriate substitution to fossil fuels. In view of the large amount of eucalyptus trees present in arid areas, we focus in this study on the investigation of using eucalyptus biodiesel as fuel in diesel engine. Eucalyptus oil is converted by transesterification into biodiesel. Eucalyptus biodiesel characterization shows that the physicochemical properties are comparable to those of diesel fuel. In the second phase, a single cylinder air-cooled, DI diesel engine was used to test neat eucalyptus biodiesel and its blends with diesel fuel in various ratios (75, 50, and 25 by v%) at several engine loads. The engine combustion parameters such as peak pressure, rate of pressure rise, and heat release rate are determined. Performances and exhaust emissions are also evaluated at all operating conditions. Results show that neat eucalyptus biodiesel and its blends present significant improvements of carbon monoxide, unburned hydrocarbon, and particulates emissions especially at high loads with equivalent performances to those of diesel fuel. However, the NOx emissions are slightly increased when the biodiesel content is increased in the blend.


2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Fenlian Huang ◽  
Jilin Lei ◽  
Qianfan Xin

Abstract This paper investigates the operating characteristics of an off-road diesel engine to enhance its power performance in plateau. First, the impacts of altitude on the power, fuel economy, and emissions characteristics were analyzed by a bench test. Second, the combustion and overall performance working at different altitudes were studied by three-dimensional numerical simulation, including the relationship between fuel injection parameters and engine performance. The results showed that altitude significantly affects the performance of the off-road diesel engine. As the altitude increased from 0 m to 2000 m, the engine power decreased as much as 4.3%, and the brake-specific fuel consumption (BSFC) increased as much as 6%. At the peak torque condition, the intake manifold boost pressure and the exhaust manifold pressure both reduced with a rise of altitude, while the intake and exhaust manifold temperatures both increased with a rise of altitude. Finally, after comparing the in-cylinder flow conditions and combustion characteristics given by six combustion chamber designs that have different shrinkage ratios, the engine performance at 4000 m altitude with five different fuel spray angles were further optimized. The engine rated power increased by 8.2% when the shrinkage ratio was 7.28% and the fuel spray angle was 150 deg at the 4000 m altitude.


Author(s):  
Y. V. Aghav ◽  
P. A. Lakshminarayanan ◽  
M. K. G. Babu ◽  
N. S. Nayak ◽  
A. D. Dani

A phenomenological model for smoke prediction from a direct injection (DI) diesel engine is newly evolved from an eddy dissipation model of Dent [1]. The turbulence structure of fuel spray is developed by incorporating the wall impingement to explain smoke formed in free and wall portions. The spray wall interaction is unavoidable in case of modern DI diesel engines of bore less than 125 mm. The new model is one dimensional and based on the recent phenomenological description of spray combustion in direct injection diesel engine. Integration of net soot rate and no need to use empirical tuning constants are the important features, which distinguish the model from existing models. Smoke values are successfully predicted using this model for an engine with heavy-duty applications under widely varying operating conditions.


2013 ◽  
Vol 768 ◽  
pp. 218-225 ◽  
Author(s):  
M. Parthasarathy ◽  
J. Isaac Joshua Ramesh Lalvani ◽  
B. Parthiban ◽  
K. Annamalai

Random extraction and consumption of fossil fuels have leads to a reduction in petroleum reserves. As for as developing countries like India is connected the need to search for alternative fuels is most urgent as India is heavily dependent upon the import of petroleum to meet its demands for automotive and power sectors. This has inspired curiously in alternative sources for petroleum based fuels. An alternative fuel must be economically competitive and environmentally acceptable. India has great potential for production of biofuels like Biodiesel from vegetable seeds. In the quest to find an alternative to the existing diesel and petrol fuels various Biodiesel and alcohol has been tried and tested in the Internal Compression engine. In this direction, an attempt has been made to investigate the performance and emission characteristic of Biodiesels and compare it with diesel. The Biodiesels considered are Tamanu, Mahua and Pongamia were tested with four stroke diesel engine. A drastic improvement in reduction of Hydrocarbon (HC) and Carbon monoxide (CO) were found for Biodiesels at high engine loads. Smoke and Nitrogen oxides (NOx) were slightly higher for Biodiesels. Biodiesels exposed similar combustion stages to diesel fuel. Therefore use of transesterified vegetable oils can be partially substituted for the diesel fuel at most operating conditions in term of the performance parameters and emissions without any engine modification.


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