Analysis of Throttle Opening Variation Impact on a Diesel Engine Performance Using Second Law of Thermodynamics

2009 ◽  
Author(s):  
B. B. Sahoo ◽  
U. K. Saha ◽  
N. Sahoo ◽  
P. Prusty
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Fuel Efficiency ◽  
Engine Performance ◽  
Second Law Of Thermodynamics ◽  
Operating Conditions ◽  
Second Law ◽  
Engine Fuel ◽  
Availability Analysis ◽  
Second Law Analysis

The fuel efficiency of a modern diesel engine has decreased due to the recent revisions to emission standards. For an engine fuel economy, the engine speed is to be optimum for an exact throttle opening (TO) position. This work presents an analysis of throttle opening variation impact on a multi-cylinder, direct injection diesel engine with the aid of Second Law of thermodynamics. For this purpose, the engine is run for different throttle openings with several load and speed variations. At a steady engine loading condition, variation in the throttle openings has resulted in different engine speeds. The Second Law analysis, also called ‘Exergy’ analysis, is performed for these different engine speeds at their throttle positions. The Second Law analysis includes brake work, coolant heat transfer, exhaust losses, exergy efficiency, and airfuel ratio. The availability analysis is performed for 70%, 80%, and 90% loads of engine maximum power condition with 50%, 75%, and 100% TO variations. The data are recorded using a computerized engine test unit. Results indicate that the optimum engine operating conditions for 70%, 80% and 90% engine loads are 2000 rpm at 50% TO, 2300 rpm at 75% TO and 3250 rpm at 100% TO respectively.

Low-sooting combustion in a small-bore high-speed direct-injection diesel engine using narrow-angle injectors

2008 ◽  
Vol 222 (10) ◽  
pp. 1927-1937 ◽  
Author(s):  
T-G Fang ◽  
R E Coverdill ◽  
C-F F Lee ◽  
R A White
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Direct Injection ◽  
Fuel Efficiency ◽  
Operating Conditions ◽  
Injection Timing ◽  
Exhaust Pipe ◽  
Injection Angle ◽  
Direct Injection Diesel Engine ◽  
Combustion Flame

An optically accessible high-speed direct-injection diesel engine was used to study the effects of injection angles on low-sooting combustion. A digital high-speed camera was employed to capture the entire cycle combustion and spray evolution processes under seven operating conditions including post-top-dead centre (TDC) injection and pre-TDC injection strategies. The nitrogen oxide (NO x) emissions were also measured in the exhaust pipe. In-cylinder pressure data and heat release rate calculations were conducted. All the cases show premixed combustion features. For post-TDC injection cases, a large amount of fuel deposition is seen for a narrower-injection-angle tip, i.e. the 70° tip, and ignition is observed near the injector tip in the centre of the bowl, while for a wider-injection-angle tip, namely a 110° tip, ignition occurs near the spray tip in the vicinity of the bowl wall. The combustion flame is near the bowl wall and at the central region of the bowl for the 70° tip. However, the flame is more distributed and centralized for the 110° tip. Longer spray penetration is found for the pre-TDC injection timing cases. Liquid fuel impinges on the bowl wall or on the piston top and a fuel film is formed. Ignition for all the pre-TDC injection cases occur in a distributed way in the piston bowl. Two different combustion modes are observed for the pre-TDC injection cases including a homogeneous bulky combustion flame at earlier crank angles and a heterogeneous film combustion mode with luminous sooting flame at later crank angles. In terms of soot emissions, NO x emissions, and fuel efficiency, results show that the late post-TDC injection strategy gives the best performance.

Layer-by-layer mixing in engines with direct gasoline injection

2020 ◽  
Keyword(s):  
Diesel Engine ◽  
Internal Combustion Engine ◽  
Gasoline Engine ◽  
Combustion Engine ◽  
Direct Injection ◽  
Fuel Efficiency ◽  
Layer By Layer ◽  
Engine Fuel ◽  
Working Process ◽  
Layered Charge

Features of the design and operation of engines with direct injection of gasoline into the cylinders and layer-by-layer mixing are considered. Opportunities of improving the engine fuel efficiency and exhaust gases toxicity characteristics with this organization of the working process are shown. Problems arising when organizing such a working process of a gasoline engine are noted. Keywords internal combustion engine; diesel engine; gasoline engine; direct injection; layer-by-layer mixing; layered charge; lean mixture

Second Law Analysis and Synthesis of Solar Collector Systems

1981 ◽  
Vol 103 (1) ◽  
pp. 23-28 ◽  
Author(s):  
A. Bejan ◽  
D. W. Kearney ◽  
F. Kreith
Keyword(s):  
Heat Transfer ◽  
Solar Collector ◽  
Second Law Of Thermodynamics ◽  
Ambient Air ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Second Law ◽  
Second Law Analysis ◽  
Analysis And Synthesis ◽  
Minimum Heat

The second law of thermodynamics is used to analyze the potential for exergy conservation in solar collector systems. It is shown that the amount of useful energy (exergy) delivered by solar collector systems is affected by heat transfer irreversibilities occurring between the sun and the collector, between the collector and the ambient air, and inside the collector. Using as working examples an isothermal collector, a nonisothermal collector, and the design of the collector-user heat exchanger, the optimum operating conditions for minimum heat transfer irreversibility (maximum exergy delivery) are derived.

scholarly journals Prediction and Analysis of Engine Friction Power of a Diesel Engine Influenced by Engine Speed, Load, and Lubricant Viscosity

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Devendra Singh ◽  
Fengshou Gu ◽  
John D. Fieldhouse ◽  
Nishan Singh ◽  
S. K. Singal
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Direct Injection ◽  
Empirical Relation ◽  
Vital Role ◽  
Operating Conditions ◽  
Engine Fuel ◽  
Friction Power ◽  
Engine Friction ◽  
Lubricant Viscosity

Automotive industries made a paradigm shift in selection of viscometrics of engine lubricant, from higher to lower viscosity grade, for improving fuel economy of vehicles. Engine fuel consumption is influenced by friction between the various engine components. Engine friction power (FP) of a direct injection diesel engine is calculated from the measured value of in-cylinder pressure signals at various operating conditions. For predicting FP, as a function of speed, load, and lubricant viscosity, a full factorial design of experiments (DOE) was formulated and an empirical correlation was developed. Response surface methodology (RSM) was used for analyzing the dominant parameters and their interactions, which influence engine friction power significantly. Predicted results of engine FP are in good agreement with measured values at all operating points. ANOVA and RSM analysis revealed that the significant parameters influencing engine FP are speed, load, viscosity, speed-load, and speed-viscosity. The effect of engine lubricant viscosity on friction power of a diesel engine was insignificant at low speed, whereas, at high speed, it played a vital role. The empirical relation developed for predicting FP is very useful in estimating engine friction power for various combinations of engine speeds, loads, and lubricant viscosity without running the engine.

A Comprehensive Model for Pilot-Ignited, Coal-Water Mixture Combustion in a Direct-Injection Diesel Engine

1990 ◽  
Vol 112 (3) ◽  
pp. 384-390
Author(s):  
S. Wahiduzzaman ◽  
P. N. Blumberg ◽  
R. Keribar ◽  
C. I. Rackmil
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Direct Injection ◽  
Accurate Determination ◽  
Engine Performance ◽  
Operating Conditions ◽  
Combustion Model ◽  
Water Mixture ◽  
Engine Design ◽  
Pilot Fuel

A combustion model has been developed for a direct-injected diesel engine fueled with coal-water slurry mixture (CWM) and assisted by diesel pilot injection. The model combines the unique heat and mass transport and chemical kinetic processes of CWM combustion with the normal in-cylinder processes of a diesel engine. It includes a two-stage evaporation submodel for the drying of the CWM droplet, a global kinetic submodel for devolatilization, and a char combustion submodel describing surface gasification by oxygen, carbon dioxide, and water vapor. The combustion volume is discretized into multiple zones, each of whose individual thermochemistry is determined by in-situ equilibrium calculations. This provides an accurate determination of the boundary conditions for the CWM droplet combustion submodels and the gas phase heat release. A CWM fuel jet development, entrainment, and mixing submodel is used to calculate the mass of unburned air in each of the burned zones. A separate submodel of diesel pilot fuel combustion is incorporated into the overall model, as it has been found that pilot fuel is required to achieve satisfactory combustion under many operating conditions. The combustion model is integrated with an advanced engine design analysis code. The integrated model can be used as a tool for exploration of the effects of fuel characteristics, fuel injection parameters, and engine design variables on engine performance, and in the assessment of the effects of component design modifications on the overall efficiency of the engine and the degree of coal burnout achieved.

The Emission Characteristics of the Emulsified Fuel and its Mechanism Research of Reducing Diesel Engine NOx Formation

2012 ◽  
Vol 550-553 ◽  
pp. 516-521
Author(s):  
Yu Xiang Ma ◽  
De Fu Wang ◽  
Rui Sun ◽  
Zhen Bin Chen
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Fuel Efficiency ◽  
Emission Characteristics ◽  
Engine Fuel ◽  
Nox Formation ◽  
Emulsified Fuel ◽  
No Formation ◽  
Physical Chemical ◽  
Mechanism Research

A non-turbocharged, direct-injection single-cylinder 1135 diesel engine was measured to investigate the engine fuel economy and emission characteristics with emulsified fuel that contains 18% water by volume. At the same time, the mechanism of reducing diesel engine NOX formation was discussed. The results showed that the diesel engine fueled with emulsified fuel leads to significant decrease in the emissions of soot and NOx and proper increase in fuel-efficiency without modifications in engine structures comparing with the diesel fuel. This paper analyzed that the water physical chemical role has an effect on reducing emulsified fuel thermal NO and prompt NO formation.

Modeling and Analysis of Fuel Injection Split for Diesel Engine Active Fueling Control

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Fengjun Yan ◽  
Song Chen ◽  
Xiangrui Zeng ◽  
Junfeng Zhao ◽  
Junmin Wang
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Fuel Efficiency ◽  
Operating Conditions ◽  
Model Parameters ◽  
Engine Fuel ◽  
Modeling And Analysis ◽  
Thermal Boundary Conditions ◽  
Indicated Mean Effective Pressure ◽  
Fueling Control

With the improvements in Diesel engine injection systems, the fueling-path, which is more accurate, flexible, and faster than the air-path, can be actively utilized in conventional and advanced combustion mode controls, especially for enhancing the combustion transient performance. In this paper, fuel injection split models are proposed to describe the relationship between fuel split ratio and two combustion outputs, i.e., the crank angle at 50% heat released (CA50) and the indicated mean effective pressure (IMEP). The model parameters are related to the engine in-cylinder thermal boundary conditions, referred to as the in-cylinder conditions (ICCs). The models were verified by engine experimental data with identical and different ICCs under different engine operating conditions. Such models can be potentially utilized in active fueling control for Diesel engine combustion control, and therefore benefit engine fuel efficiency and reduce engine-out emissions.

scholarly journals An analytical and experimental study of performance on jatropha biodiesel engine

2009 ◽  
Vol 13 (3) ◽  
pp. 69-82 ◽  
Author(s):  
Thirunavukkarasu Ganapathy ◽  
Parkash Gakkhar ◽  
Krishnan Murugesan
Keyword(s):  
Diesel Engine ◽  
Thermodynamic Model ◽  
Direct Injection ◽  
Experimental Studies ◽  
Engine Performance ◽  
Performance Characteristics ◽  
Injection Timing ◽  
Engine Fuel ◽  
Cylinder Pressure ◽  
Promising Alternative

Biodiesel plays a major role as one of the alternative fuel options in direct injection diesel engines for more than a decade. Though many feed stocks are employed for making biodiesel worldwide, biodiesel derived from domestically available non-edible feed stocks such as Jatropha curcas L. is the most promising alternative engine fuel option especially in developing countries. Since experimental analysis of the engine is pricey as well as more time consuming and laborious, a theoretical thermodynamic model is necessary to analyze the performance characteristics of jatropha biodiesel fueled diesel engine. There were many experimental studies of jatropha biodiesel fueled diesel engine reported in the literature, yet theoretical study of this biodiesel run diesel engine is scarce. This work presents a theoretical thermodynamic study of single cylinder four stroke direct injection diesel engine fueled with biodiesel derived from jatropha oil. The two zone thermodynamic model developed in the present study computes the in-cylinder pressure and temperature histories in addition to various performance parameters. The results of the model are validated with experimental values for a reasonable agreement. The variation of cylinder pressure with crank angle for various models are also compared and presented. The effects of injection timing, relative air fuel ratio and compression ratio on the engine performance characteristics for diesel and jatropha biodiesel fuels are then investigated and presented in the paper.

Two-Stroke Marine Diesel Engine Variable Injection Timing System Performance Evaluation and Optimum Setting for Minimum Fuel Consumption at Acceptable NOx Levels

2014 ◽  
Author(s):  
Dimitrios T. Hountalas ◽  
Spiridon Raptotasios ◽  
Antonis Antonopoulos ◽  
Stavros Daniolos ◽  
Iosif Dolaptzis ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Injection Timing ◽  
Nox Emissions ◽  
Pressure Measurements ◽  
Cylinder Pressure ◽  
Start Of Injection

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).

Characteristics of Water-in-Diesel Emulsions in a Single Cylinder Compression Ignition Engine

2014 ◽  
Author(s):  
Teja Gonguntla ◽  
Robert Raine ◽  
Leigh Ramsey ◽  
Thomas Houlihan
Keyword(s):  
Fuel Consumption ◽  
Direct Injection ◽  
Engine Performance ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Brake Specific Fuel Consumption ◽  
Compression Ignition Engine ◽  
Oil Emulsion ◽  
Single Cylinder ◽  
Performance And Emission

The objective of this project was to develop both engine performance and emission profiles for two test fuels — a 6% water-in-diesel oil emulsion (DOE-6) fuel and a neat diesel (D100) fuel. The testing was performed on a single cylinder, direct-injection, water-cooled diesel engine coupled to an eddy current dynamometer. Output parameters of the engine were used to calculate Brake Specific Fuel Consumption (BSFC) and Engine Efficiency (η) for each test fuel. DOE-6 fuels generated a 24% reduction in NOX and a 42% reduction in Carbon Monoxide emissions over the tested operating conditions. DOE-6 fuels presented higher ignition delays — between 1°-4°, yielded 1%–12% lower peak cylinder pressures and produced up to 5.5% lower exhaust temperatures. Brake Specific Fuel consumption increased by 6.6% for the DOE-6 fuels as compared to the D100 fuels. This project is the first research done by a New Zealand academic institution on water-in-diesel emulsion fuels.

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