scholarly journals Investigating Combustion Process of N-Butanol-Diesel Blends in a Diesel Engine with Variable Compression Ratio

2021 ◽  
Vol 3 (3) ◽  
pp. 618-628
Author(s):  
György Szabados ◽  
Kristóf Lukács ◽  
Ákos Bereczky
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Compression Ratio ◽  
Release Rate ◽  
Ignition Delay ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Injection Angle ◽  
Combustion Properties

The search for alternative fuels for internal combustion engines is ongoing. Among the alternatives, plant-based fuels can also be mentioned. Alcohol is not a common fuel for diesel engines because the physical and chemical properties of the alcohols are closer to those of gasoline. In our research, the combustion properties of diesel-n-butanol mixtures have been investigated to obtain results on the effect of butanol blending on combustion. Among the combustion properties, ignition delay, in-cylinder pressure, and heat release rate can be mentioned. They have been observed under different compression conditions on an engine on which the compression ratio can be adjusted. The method used was a quite simple one, so the speed of the engine was set to a constant 900 rpm without load, while three compression ratios (19.92, 15.27, and 12.53) were adjusted with a fuel flow rate of 13 mL/min and the pre-injection angle of 18° BTDC. Blending butanol into the investigated fuel does not significantly affect maximal values of indicated pressure, while much more effect on the pressure rising rate can be detected. Furthermore, heat release rate and ignition delay increased at every compression ratio investigated. Despite the low blending rates of butanol in the mixtures, butanol significantly affects the combustion parameters, especially at high compression ratios.

scholarly journals Non-Chloride in Situ Preparation of Nano-Cuprous Oxide and Its Effect on Heat Resistance and Combustion Properties of Calcium Alginate

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1760 ◽  
Author(s):  
Peiyuan Shao ◽  
Peng Xu ◽  
Lei Zhang ◽  
Yun Xue ◽  
Xihui Zhao ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Heat Release ◽  
Hybrid Materials ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cuprous Oxide ◽  
Calcium Alginate ◽  
Combustion Process ◽  
Protective Layer ◽  
Combustion Properties

With Cu2+ complexes as precursors, nano-cuprous oxide was prepared on a sodium alginate template excluded of Cl− and based on which the calcium alginate/nano-cuprous oxide hybrid materials were prepared by a Ca2+ crosslinking and freeze-drying process. The thermal degradation and combustion behavior of the materials were studied by related characterization techniques using pure calcium alginate as a comparison. The results show that the weight loss rate, heat release rate, peak heat release rate, total heat release rate and specific extinction area of the hybrid materials were remarkably lower than pure calcium alginate, and the flame-retardant performance was significantly improved. The experimental data indicates that nano-cuprous oxide formed a dense protective layer of copper oxide, calcium carbonate and carbon by lowering the initial degradation temperature of the polysaccharide chain during thermal degradation and catalytically dehydrating to char in the combustion process, and thereby can isolate combustible gases, increase carbon residual rates, and notably reduce heat release and smoke evacuation.

Numerical Simulation on the Combustion Characteristics of Armored Vehicle Diesel in Plateau Area

2012 ◽  
Vol 457-458 ◽  
pp. 607-610
Author(s):  
Feng Lu ◽  
Meng Chao Guo ◽  
Guang Jun Guo
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Combustion Process ◽  
Combustion Characteristics ◽  
Maximum Increase ◽  
Injection Angle ◽  
Maximum Value ◽  
Plateau Area ◽  
Armored Vehicle

A simulation model on working process of certain armored vehicle turbocharged diesel engine is proposed with Hiroyasu combustion model.Then the combustion characteristics of the diesel in 4km altitude is calculated. The combustion process is improved via adjusting optimum advanced injection angle(θi) which performed in plateau area.The results show: when the altitude is from 0m to 4000m, the center of gravity for heat release rate is delayed 7°CA,HRRmax (maximum value of Heat Release Rate) reduces 0.009KJ/°CA, pmax (maximum value of cylinder Pressure ) reduces1.6MPa,Tmax(maximum value of combus -tion temperature ) increases 220°C above. When θi is advanced during possible scope, HRRmax increases 0.008KJ/°CA,pmax increases 1.0MPa,Tmax increase 150°C. In view of the restriction of the pmax and the maximum increase rate of p, the optimum θi is fixed on to advanced 4°CA. The simulation results supply a research foundation for the improvement of diesel performance in Plateau.

The Effects of Spray Angles on Spray Combustion of Diesel and Biodiesel in Diesel Engines

2014 ◽  
Author(s):  
Cai Shen ◽  
Way Lee Cheng ◽  
Chia-fon F. Lee
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Ignition Delay ◽  
Spray Angle ◽  
Soot Emission ◽  
Injection Angle ◽  
Combustion Pressure ◽  
Piston Bowl ◽  
Main Injection

The effects of injection angle on the spray dynamics, combustion process and soot emission were studied. Two different fuels, diesel and biodiesel, were tested on a DIATA optical engine by performing numerical simulation using the modified KIVA III V2. Simulations under three different injection angles and two different injection pressures were performed. The model was verified by comparing the spray penetrations and pressure traces with the experimental measurements. The simulation results show that lower injection pressure strengthens spray operation, and longer ignition delay and lower peak combustion pressure and peak heat release rate are observed. Injection angle of 110° produces the highest peak combustion pressure and heat release rate for diesel fuel. Unlike diesel combustion, the peak combustion pressure and heat releases rate for biodiesel increases as the spray angle narrows. Soot located in the squish or the regions above the piston bowl are readily oxidized due to abundance of oxygen. Portions of fuel are burnt in the region about the piston bowl or squish for both spray angle of 150° and 70°. Soot located within the piston bowl is oxidized at a much slower rate due to deficient oxygen after combustion. Soot emission mainly due to soot within in the piston bowl at the end of combustion. Any strategy that pushes soot out of piston can improve the oxidization process, thus, reducing soot emission. Extra oxygen in biodiesel also helps in reducing the emission. Biodiesel has longer ignition delay over diesel for initial injection. Ignition delay for main injection is negligible in all the cases studied due to the cylinder condition upon main injection. Soot emissions are reduced from biodiesel blends and this is consistent with the general observation.

Combustion and Emission Characteristics of Dual Fuel Engine for Different Parameters

2021 ◽  
Vol 13 (4) ◽  
Author(s):  
Jianjun Zhu ◽  
Peng Li ◽  
Yufeng Xie ◽  
Xin Geng
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Heat Release Rate ◽  
Compression Ratio ◽  
Release Rate ◽  
Emission Characteristics ◽  
Soot Emission ◽  
Cylinder Pressure ◽  
Fuel Delivery ◽  
Soot Emissions

The effects of compression ratio and fuel delivery advance angle on the combustion and emission characteristics of premixed methanol charge induced ignition by Fischer Tropsch diesel engine were investigated using a CY25TQ diesel engine. In the process of reducing the compression ratio from 16.9 to 15.4, the starting point of combustion is fluctuating, the peak of in-cylinder pressure and the maximum pressure increase rate decrease by 44.5% and 37.7% respectively. The peak instantaneous heat release rate increases by 54.4%. HC and CO emissions are on a rising trend. NOx and soot emissions were greatly decreased. The soot emission has the biggest drop of 50%. Reducing the fuel delivery advance angle will make the peak of in-cylinder pressure and the peak of pressure rise rate increase while the peak of heat release rate decreases. The soot emission is negatively correlated with the fuel delivery advance angle. When the fuel delivery advance angle is 16° CA, the soot emissions increased the most by 130%.

A comparative study of the effect of compression ratio on the efficiency and flame development angle in a Cooperative Fuel Research engine fueled with binary gasoline–alcohol blends

2019 ◽  
pp. 146808741985910 ◽  
Author(s):  
Guillermo Rubio-Gómez ◽  
Lis Corral-Gómez ◽  
David Rodriguez-Rosa ◽  
Fausto A Sánchez-Cruz ◽  
Simón Martínez-Martínez
Keyword(s):  
Comparative Study ◽  
Compression Ratio ◽  
Alternative Fuels ◽  
Internal Combustion Engines ◽  
Fossil Fuels ◽  
Combustion Process ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Flame Development ◽  
The Impact

In the last few years, increasing concern about the harmful effects of the use of fossil fuels in internal combustion engines has been observed. In addition, the limited availability of crude oil has driven the interest in alternative fuels, especially biofuels. In the context of spark ignition engines, bioalcohols are of great interest owing to their similarities and blend capacities with gasoline. Methanol and ethanol have been widely used, mainly due to their knocking resistance. Another alcohol of great interest is butanol, thanks to its potential of being produced as biofuel and its heat value closer to gasoline. In this study, a comparative study of gasoline–alcohol blend combustion, with up to 20% volume, with neat gasoline has been carried out. A single-cylinder, variable compression ratio, Cooperative Fuel Research-type spark ignition engine has been employed. The comparison is made in terms of fuel conversion efficiency and flame development angle. Relevant information related to the impact in the combustion process of the use of the three main alcohols used in blends with gasoline has been obtained.

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 Analysis on Pattern of Heat Release Rate in Two-Stroke Slow Speed Diesel Engine (2nd Report: Prediction of the Combustion Process)

2003 ◽  
Vol 38 (5) ◽  
pp. 303-308
Author(s):  
Takeshi Imahashi ◽  
Eiji Tomita ◽  
Sadami Yoshiyama ◽  
Kouji Moriyama
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Combustion Process ◽  
Slow Speed

scholarly journals Performance, Emission and Combustion Characteristics of VCR CRDI Diesel Engine Fuelled with n-butanol Blends

2019 ◽  
Vol 16 (3) ◽  
pp. 6825-6843
Author(s):  
P. T. Selvan ◽  
G. S. Goteti
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Heat Release Rate ◽  
Compression Ratio ◽  
Release Rate ◽  
Research Work ◽  
Injection Pressure ◽  
Combustion Characteristics ◽  
Exhaust Emission ◽  
Performance Study

This research work indicates the analysis conducted to investigate the performance, exhaust emission and combustion characteristics of a VCR diesel engine fuelled with nbutanol blends at a rated speed of 1500 rpm with 300 bar injection pressure at compression ratios of 16, 18 and 20. The test fuel was prepared by adding n-butanol 10% (NB10) and 20% (NB20) to diesel by volume. The combustion characteristics investigated were; rise in-cylinder pressures, net heat release rate, cumulative heat release rate and mass fraction of fuel burned at all loads using three compression ratios. The emission and performance study also conducted. The higher heat release rates, increased cylinder pressures were observed for both the blends compared to diesel. Increased brake thermal efficiency observed at higher compression ratio for NB20 blend. It had also been observed that the emissions of CO2, HC and NOx were increased for both the blends, while CO emissions decreased in trend with an increase in compression ratio and blend strength.

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