Analysis of a diesel engine fueled with ternary fuel blends and alumina nano-additives at various combustion chamber geometries

2020 ◽  
pp. 1-12 ◽  
Author(s):  
George Antony Casmir Jayaseelan ◽  
Anderson Arul Gnana Dhas ◽  
Harish Venu ◽  
Jayaprabakar Jayaraman ◽  
Prabhu Appavu
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Heat Release Rate ◽  
Release Rate ◽  
Combustion Zone ◽  
High Performance ◽  
Specific Energy Consumption ◽  
Fuel Mixture ◽  
Nano Additives ◽  
The Impact

The present study investigates the impact of various combustion chamber geometries in a direct injection engine fueled with diesel–biodiesel–ethanol blends mixed with alumina nano-additives, named as high-performance fuel (HPF). The HPF was subjected to various combustion bowl geometries including standard hemispherical chamber geometry (SG), shallow depth reentrant bowl geometry (CG1), toroidal reentrant chamber geometry (CG2), and toroidal chamber geometry (CG3). Performance results reveal that in comparison with the SG-HPF arrangement, brake thermal efficiency increased by 11.51% and brake-specific energy consumption decreased by 10.37% when using the CG2-HPF arrangement. For emmisions, CG2-HPF reduced carbon monoxide, hydrocarbon, and smoke emissions by 33.53%, 18.35%, and 14.37%, respectively, in comparison with SG-HPF. Regarding combustion, CG2-HPF resulted in a high heat release rate owing to the reentrant chamber profile of CG2 which improves the air–fuel mixture rate, atomization, and evaporation rate, resulting in more efficient combustion, increased cylinder pressure, and increased heat release rate. Thanks to the geometry of the reentrant profile, the turbulent kinetic energy of the fuel mixture is maintained and returned to the combustion zone. Thus, the stagnation of rich mixtures within the combustion zone tend to decrease. Overall, the CG2 geometry was found to be the optimum geometry profile for HPF, based on improved performance and combustion characteristics, as well as reduced exhaust emissions.

Influence of the Indicator Channel and Indicator Valve on the Heat Release Characteristics of Medium Speed Marine Diesel Engines

2013 ◽  
Vol 588 ◽  
pp. 149-156 ◽  
Author(s):  
Stanisław Polanowski ◽  
Rafał Pawletko ◽  
Kazimierz Witkowski
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Diesel Engines ◽  
Diagnostic Information ◽  
Injection System ◽  
Indicator Diagram ◽  
Medium Speed ◽  
Marine Diesel ◽  
The Impact

Analysis of the indicator diagram is the basis of technical state evaluation of marine diesel engines. The indicator diagram contains a large amount of diagnostic information. A major problem for the diagnostic use of the indicator diagram is the pressure sensor location. Indicator channel and valve may introduce significant distortions in the resulting pressure. The paper presents results of research conducted on the medium speed laboratory engine Al 25/30. Pressure measurement (indication) was made by the sensor placed directly in the cylinder (instead of starting air valve), before the indicator valve (with special Kistler adapter) and on the indicator valve. Distortion of heat release characteristics for the sensor placed on the indicator valve is important, but it is estimated that diagnostic information is not erased. For medium speed engines is to be expected the use of a portable pressure sensors placed on the indicator valve. For this reason, further research is needed to assess the impact of channels and valves on different cylinders. During the research the course of heat release rate q and the heat released Q were determined. The curve of heat release rate q is a full equivalent to fuel injection pressure curve in the fuel pipes. It allows identification of the failure of the injection system. The curve of Q allows such determination and assessment of internal efficiency of the cylinder.

scholarly journals On the Local Heat Release Rate in a Combustion Chamber of Gas Turbine

1962 ◽  
Vol 5 (19) ◽  
pp. 505-510
Author(s):  
Takashi SATO ◽  
Itaru MICHIYOSHI ◽  
Ryuichi MATSUMOTO
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Heat Release Rate ◽  
Release Rate ◽  
Local Heat

Simultaneous Imaging of OH* Chemiluminescence and Flame Luminosity of Diesel and Biodiesel Spray Combustion

2011 ◽  
Author(s):  
Ji Zhang ◽  
Tiegang Fang
Keyword(s):  
Ambient Temperature ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Soot Formation ◽  
Combustion Process ◽  
Spray Combustion ◽  
Chemiluminescence Intensity ◽  
High Temperature Reaction ◽  
The Impact

The research on the spray combustion of diesel and biodiesel is vital to the understanding of emission formation and optimal utilization of fuel. This paper studies the biodiesel and diesel spray combustion in a constant volume chamber under different simulated diesel engine conditions. The ambient temperature at fuel injection varied from 800K to 1200K, while the ambient oxygen concentration was maintained at 21%. Simultaneous high speed imaging of OH* chemiluminescence and flame luminosity was employed to visualize the whole combustion process. Heat release rate was analyzed based on the measured combustion pressure. The apparent heat release rate analysis shows that biodiesel has a shorter ignition delay time than diesel, and biodiesel has a smaller cumulative heat release value due to its lower heating value. The overlaying image of OH* chemiluminescence and flame luminosity clearly identifies the high temperature reaction regions and soot formation regions. The line-of-sight images agree with the published observation that the hydroxyl radical is formed on the lean side of the flame edge. Decreasing ambient temperature greatly reduces the OH* chemiluminescence intensity of the diesel combustion, while the impact is smoother and milder for biodiesel combustion. Biodiesel shows a significantly lower level of flame luminosity than diesel under all conditions. These combined observations lead to a speculation that the soot oxidation process may serve as an important contributor to OH* chemiluminescence intensity for late stage combustion, and biodiesel shows a tendency to produce less soot than diesel under the investigated conditions.

Influence of the Spatial and Temporal Interaction Between Diesel Pilot and Directly Injected Natural Gas Jet on Ignition and Combustion Characteristics

2017 ◽  
Author(s):  
Georg Fink ◽  
Michael Jud ◽  
Thomas Sattelmayer
Keyword(s):  
Natural Gas ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Combustion Process ◽  
Gas Jet ◽  
Injection Timing ◽  
Release Rates ◽  
Temporal Interaction ◽  
The Impact

In this paper, pilot-ignited high pressure dual-fuel (HPDF) combustion of a natural gas jet is investigated on a fundamental basis by applying two separate single-hole injectors to a rapid compression expansion machine (RCEM). A Shadowgraphy system is used for optical observations, and the combustion progress is assessed in terms of heat release rates. The experiments focus on the combined influence of injection timing and geometrical jet arrangement on the jet interaction and the impact on the combustion process. In a first step, the operational range for successful pilot self-ignition and transition to natural gas jet combustion is determined, and the restricting phenomena are identified by analyzing the shadowgraph images. Within this range, the combustion process is assessed by evaluation of ignition delays and heat release rates. Strong interaction is found to delay or even prohibit pilot ignition, while it facilitates a fast and stable onset of the gas jet combustion. Furthermore, it is shown that the heat release rate is governed by the time of ignition with respect to the start of natural gas injection — as this parameter defines the level of premixing. Evaluation of the time of gas jet ignition within the operability map can therefore directly link a certain spatial and temporal interaction to the resulting heat release characteristics. It is finally shown that controlling the heat release rate through injection timing variation is limited for a certain angle between the two jets.

scholarly journals Effect of ratio between incoming cool air and outgoing hot gases on behaviour of compartment fire

2019 ◽  
pp. 326-326
Author(s):  
Olivier Zatao-Samedi ◽  
Abbo Oumarou ◽  
Jean M’Boliguipa ◽  
Mvogo Onguene ◽  
Ruben Mouangue
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Room Temperature ◽  
Data Acquisition System ◽  
Main Element ◽  
Compartment Fire ◽  
Release Rates ◽  
The Impact ◽  
Reduced Scale

Many factors have an influence on the development of compartment fire notably on its heat release rate as well as on its capability to propagate and become a flashover situation. The main element which rapidly conveys fire from a compartment to another is hot smoke flowing out through openings of the compartment source of fire. The present work aims to experiment the impact of the variation of heat release rate of the source on the behaviour of fire. So, five fire tests with different heat release rates were thus carried out in a reduced scale room. Temperature of burned gases inside the room, were measured during tests by sensors connected to a data acquisition system. Results revealed that temperature of burned gases as well as its content in carbon monoxide, evolves differently according to two ranges of the incoming air/outgoing gases ratio. The first range of which the ratio is lower than 2, corresponds to the case where both parameters decrease rapidly. The second range of which the ratio is higher than 2, corresponds to the case where both parameters decrease moderately. The transition from the first to the second range, points out the passing from the ventilation-controlled fire to the fuel-controlled fire. A relation expressing the variation of the mass flow rate of outgoing burned gases according to the heat release rate of the fire source has been given.

Experimental and Theoretical Optimization of Combustion Chamber and Fuel Distribution for the Low Emission DI Diesel Engine

2001 ◽  
Author(s):  
Yoshiyuki Kidoguchi ◽  
Michiko Sanda ◽  
Kei Miwa
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Combustion Chamber ◽  
Heat Release Rate ◽  
Release Rate ◽  
Combustion Process ◽  
Mixture Distribution ◽  
Initial Mixture ◽  
Injection Timing ◽  
Initial Heat

Abstract This study investigated the effect of combustion chamber geometry and initial mixture distribution on combustion process in a direct-injection diesel engine by means of experiment and CFD calculation. The high squish combustion chamber with squish lip could produce simultaneous reduction of NOx and particulate emissions with retarded injection timing in the real engine experiment. According to the CFD computation, the high squish combustion chamber with central pip is effective to continue combustion under the squish lip until the end of combustion and the combustion region forms rich and high turbulence atmosphere, which reduces NOx emissions. This chamber can also reduce initial burning because combustion continues under the squish lip. The CFD computation is also carried out in order to investigate the effect of initial mixture distribution on combustion process. The results suggest that mixture distribution affects the history of heat release rate. When fuel is distributed in the bottom or wide region in the combustion chamber, burned gas tends to spread to the cavity center and initial heat release rate becomes high. On the contrary, the high squish combustion chamber with central pip produces lower initial heat release rate because combustion with local rich condition continues long under the squish lip. Diffusion burning is promoted by high swirl motion in this chamber with keeping lower initial heat release rate.

Adjoint Methods for Elimination of Thermoacoustic Oscillations in a Model Annular Combustor via Small Geometry Modifications

2018 ◽  
Author(s):  
José G. Aguilar ◽  
Matthew P. Juniper
Keyword(s):  
Sensitivity Analysis ◽  
Time Delay ◽  
Heat Release ◽  
Combustion Chamber ◽  
Heat Release Rate ◽  
Release Rate ◽  
Gas Turbines ◽  
Acoustic Pressure ◽  
Annular Combustor ◽  
Thermoacoustic Oscillations

In gas turbines, thermoacoustic oscillations grow if moments of high fluctuating heat release rate coincide with moments of high acoustic pressure. The phase between the heat release rate and the acoustic pressure depends strongly on the flame behaviour (specifically the time delay) and on the acoustic period. This makes the growth rate of thermoacoustic oscillations exceedingly sensitive to small changes in the acoustic boundary conditions, geometry changes, and the flame time delay. In this paper, adjoint-based sensitivity analysis is applied to a thermoacoustic network model of an annular combustor. This reveals how each eigenvalue is affected by every parameter of the system. This information is combined with an optimization algorithm in order to stabilize all thermoacoustic modes of the combustor by making only small changes to the geometry. The final configuration has a larger plenum area, a smaller premix duct area and a larger combustion chamber volume. All changes are less than 6% of the original values. The technique is readily scalable to more complex models and geometries and the inclusion of further constraints, such that the combustion chamber itself should not change. This demonstrates why adjoint-based sensitivity analysis and optimization could become an indispensible tool for the design of thermoacoustically-stable combustors.

scholarly journals On the Local Heat Release Rate in a Combustion Chamber of Gas Turbine

1961 ◽  
Vol 27 (183) ◽  
pp. 1839-1845
Author(s):  
Takashi SATO ◽  
Itaru MICHIYOSHI ◽  
Ryuichi MATSUMOTO
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Heat Release Rate ◽  
Release Rate ◽  
Local Heat

scholarly journals An experimental study of the dual-fuel performance of a small compression ignition diesel engine operating with three gaseous fuels

2007 ◽  
Vol 221 (8) ◽  
pp. 943-956 ◽  
Author(s):  
J Stewart ◽  
A Clarke ◽  
R Chen
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
High Speed ◽  
Direct Injection ◽  
Specific Energy Consumption ◽  
Dual Fuel ◽  
Compression Ignition ◽  
Gaseous Fuels ◽  
Ci Engine

A dual-fuel engine is a compression ignition (CI) engine where the primary gaseous fuel source is premixed with air as it enters the combustion chamber. This homogenous mixture is ignited by a small quantity of diesel, the ‘pilot’, that is injected towards the end of the compression stroke. In the present study, a direct-injection CI engine, was fuelled with three different gaseous fuels: methane, propane, and butane. The engine performance at various gaseous concentrations was recorded at 1500 r/min and quarter, half, and three-quarters relative to full a load of 18.7 kW. In order to investigate the combustion performance, a novel three-zone heat release rate analysis was applied to the data. The resulting heat release rate data are used to aid understanding of the performance characteristics of the engine in dual-fuel mode. Data are presented for the heat release rates, effects of engine load and speed, brake specific energy consumption of the engine, and combustion phasing of the three different primary gaseous fuels. Methane permitted the maximum energy substitution, relative to diesel, and yielded the most significant reductions in CO2. However, propane also had significant reductions in CO2 but had an increased diffusional combustion stage which may lend itself to the modern high-speed direct-injection engine.

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