scholarly journals Effect of Fuel Cetane Numbers on Reducing the Ignition Delay Period and Exhaust Emissions from DI Diesel Engine

2020 ◽  
Vol 15 ◽  
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Direct Injection ◽  
Cetane Number ◽  
Injection Pressure ◽  
Exhaust Emissions ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Engine Torque ◽  
Di Diesel Engine

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.

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
Keyword(s):  
Diesel Engine ◽  
Cetane Number ◽  
Reference Value ◽  
Exhaust Emissions ◽  
Operating Conditions ◽  
Bench Test ◽  
Operating Characteristics ◽  
Di Diesel Engine ◽  
Aviation Turbine Fuel ◽  
Autoignition Delay

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.

Phenomenology of Smoke From Direct Injection Diesel Engine

2005 ◽  
Author(s):  
Y. V. Aghav ◽  
P. A. Lakshminarayanan ◽  
M. K. G. Babu ◽  
N. S. Nayak ◽  
A. D. Dani
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Operating Conditions ◽  
Turbulence Structure ◽  
One Dimensional ◽  
Direct Injection Diesel Engine ◽  
Wall Impingement ◽  
Di Diesel Engine ◽  
Dissipation Model ◽  
Wall Interaction

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.

A Predictive Ignition Delay Correlation Under Steady-State and Transient Operation of a Direct Injection Diesel Engine

2003 ◽  
Vol 125 (2) ◽  
pp. 450-457 ◽  
Author(s):  
D. N. Assanis ◽  
Z. S. Filipi ◽  
S. B. Fiveland ◽  
M. Syrimis
Keyword(s):  
Steady State ◽  
Diesel Engine ◽  
Ignition Delay ◽  
Direct Injection ◽  
Thermodynamic Simulation ◽  
Injection Pressure ◽  
Transient Operation ◽  
Load Spectrum ◽  
Two Phase ◽  
Transient Conditions

Available correlations for the ignition delay in pulsating, turbulent, two-phase, reacting mixtures found in a diesel engine often have limited predictive ability, especially under transient conditions. This study focuses on the development of an ignition delay correlation, based on engine data, which is suitable for predictions under both steady-state and transient conditions. Ignition delay measurements were taken on a heavy-duty diesel engine across the engine speed/load spectrum, under steady-state and transient operation. The dynamic start of injection was calculated by using a skip-fire technique to determine the dynamic needle lift pressure from a measured injection pressure profile. The dynamic start of combustion was determined from the second derivative of measured cylinder pressure. The inferred ignition delay measurements were correlated using a modified Arrhenius expression to account for variations in fuel/air composition during transients. The correlation has been compared against a number of available correlations under steady-state conditions. In addition, comparisons between measurements and predictions under transient conditions are made using the extended thermodynamic simulation framework of Assanis and Heywood. It is concluded that the proposed correlation provides better predictive capability under both steady-state and transient operation.

scholarly journals Preheating Of Sunflower Blended Biodiesel for the Improvement of Performance Characteristics of a DI Diesel Engine under Various Loads

2019 ◽  
Vol 8 (6) ◽  
pp. 921-926
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Dynamic Performance ◽  
Direct Injection ◽  
Specific Energy Consumption ◽  
Cetane Number ◽  
Diesel Oil ◽  
Performance Characteristics ◽  
Di Diesel Engine ◽  
And Performance

Due to fast depletion of fuel and for the huge demand of various engine fuels in large sectors and power generation, thse biodiesel which is derived from biological wastes can be a substitute of pure diesel oil. Diesel engine has the benefits of low fuel consumption, high potency, smart economical and dynamic performance. However at the identical time, the diesel engine has high NOx and soot emissions. And these two sorts of emissions provides a trade-off relationship which can bring difficulties to satisfy the necessities of emission rules of NOx and soot. This particular paper primarily reviews regarding using of preheated bio-diesel that contains 20 percentage of pure sunflower oil (biological name-Helianthus annuus) and analyses its performance characteristics for selected blend with completely variable loads. Various experiments were carried out by employing a four stroke single cylinder, direct injection, water cooled diesel engine with suitable specifications. Helianthus oil is mixed with bio diesel for fast burning inside the engine cylinder and by doing so , the Cetane number is quite high that leads to the ignition delay shorter. Therefore the overall content is preheated somewhat in order to lift its temperature so as to boost the burning process. Incorporating to this , it reduces the various emissions such as NOx, CO and smoke capacity by 2% to 3%. Various parameters are required to outline the analysis of combustion and performance characteristics of the test fuel like brake thermal efficiency(BTE),basic specific fuel consumption(BSFC), basic specific energy consumption (BSEC),temperature of the exhaust gas and emissions like NOx, unburn hydrocarbons(HC), carbon monoxide(CO) and smoke were carried out in the specified engine

Optimum control of an automotive direct injection diesel engine for low exhaust emissions

2001 ◽  
Vol 215 (11) ◽  
pp. 1225-1236 ◽  
Author(s):  
M Capobianco
Keyword(s):  
Diesel Engine ◽  
Control Strategies ◽  
Direct Injection ◽  
Experimental Information ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Control Variables ◽  
Wide Range ◽  
Di Diesel Engine ◽  
Definition Of

The paper presents the latest results of a wide investigation performed at the University of Genoa on the control of automotive direct injection (DI) diesel engines. A dedicated procedure was developed which enables analysis of the behaviour of engine operating parameters as a function of two control variables with a limited amount of experimental information and the definition of proper control strategies. A first application of the procedure is presented in the paper with reference to a typical turbocharged DI diesel engine for automotive applications. The exhaust gas recirculation (EGR) rate and the position of the turbocharger waste-gate regulating valve were assumed as control variables and the behaviour of the most important engine parameters was analysed in a wide range for 15 steady state operating conditions related to the European driving cycle. Particular attention was paid to the most significant pollutant emissions and to the exhaust boundary conditions for the application of a low temperature lean de-NOx catalyst. Two different control strategies were also developed by which the catalyst conversion efficiency and the NOx engine tail pipe emission were individually optimized, taking account of some operating limits for specific parameters.

Investigation of the Benefits of Controlling the Start of Combustion in a Direct Injection Diesel Engine Using an Optical Sensor

1994 ◽  
Vol 208 (2) ◽  
pp. 129-137 ◽  
Author(s):  
N Ladommatos ◽  
R A Balian ◽  
R Horrocks ◽  
L Cooper
Keyword(s):  
Diesel Engine ◽  
Optical Sensor ◽  
Direct Injection ◽  
Exhaust Emissions ◽  
Operating Conditions ◽  
Engine Exhaust ◽  
Diesel Engine Exhaust ◽  
Direct Injection Diesel Engine ◽  
Ignition Quality ◽  
Start Of Combustion

Results are presented which show the effect of controlling the start of combustion on direct injection diesel engine exhaust emissions at various engine operating conditions. The ability of the sensor to detect reliably the start of combustion under various engine conditions is first assessed. The effects on exhaust emissions of controlling the start of combustion is then evaluated using a fuel of reduced ignition quality.

Accurate prediction of the rate of heat release in a modern direct injection diesel engine

2002 ◽  
Vol 216 (8) ◽  
pp. 663-675 ◽  
Author(s):  
P A Lakshminarayanan ◽  
Y V Aghav ◽  
A D Dani ◽  
P S Mehta
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Direct Injection ◽  
Turbulent Energy ◽  
Operating Conditions ◽  
Combustion Model ◽  
Injection Velocity ◽  
Mixing Rate ◽  
Di Diesel Engine ◽  
Rate Of Heat Release

An accurate model for the heat release rate in a modern direct injection (DI) diesel engine is newly evolved from the known mixing controlled combustion model. The combustion rate could be precisely described by relating the mixing rate to the turbulent energy created at the exit of the nozzle as a function of the injection velocity and by considering the dissipation of energy in free air and along the wall. The complete absence of tuning constants distinguishes the model from the other zero-dimensional or pseudomultidimensional models, at the same time retaining the simplicity. Successful prediction of the history of heat release in engines widely varying in bores, rated speeds and types of aspirations, at all operating conditions, validated the model.

Combustion and Emission Characteristics of Biodiesel Fuels in a Common-Rail Diesel Engine

2005 ◽  
Author(s):  
Seung Hyun Yoon ◽  
Sung Wook Park ◽  
Dae Sik Kim ◽  
Sang Il Kwon ◽  
Chang Sik Lee
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Cetane Number ◽  
Injection Pressure ◽  
Injection Rate ◽  
Common Rail ◽  
Injection System ◽  
Emission Characteristics ◽  
Mixing Ratio ◽  
Biodiesel Fuels

A single cylinder DI (direct injection) diesel engine equipped with common-rail injection system was used to investigate the combustion and emission characteristics of biodiesel fuels. Tested fuels were conventional diesel and biodiesels obtained from unpolished rice oil and soybean oil. The volumetric blending ratios of biodiesel with diesel fuel are set at 0, 10, 20 and 40%. Experimental results show that the peak injection rate is reduced as the mixing ratio increased. The effect of the mixing ratio on the injection delay of biodiesel is not significant at the equal injection pressure. The peak combustion pressure was increased with the increase of the mixing ratio at an injection pressure of 100MPa. The ignition delay became shorter with the increase of the mixing ratio due to a higher cetane number of the biodiesel. HC and CO emissions are decreased at a high injection pressure. However, NOx emissions are increased at higher mixing ratios.

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