scholarly journals Chemiluminescence analysis of the effect of butanol-diesel fuel blends on the spray-combustion process in an experimental common rail diesel engine

2015 ◽  
Vol 19 (6) ◽  
pp. 1943-1957
Author(s):  
Simona Merola ◽  
Luca Marchitto ◽  
Cinzia Tornatore ◽  
Gerardo Valentino
Keyword(s):  
Diesel Fuel ◽  
Flame Temperature ◽  
Combustion Process ◽  
Injection Pressure ◽  
Common Rail ◽  
Pilot Injection ◽  
Soot Emission ◽  
Compression Ignition Engine ◽  
Working Cycle ◽  
Main Injection

Combustion process was studied from the injection until the late combustion phase in an high swirl optically accessible combustion bowl connected to a single cylinder 2-stroke high pressure common rail compression ignition engine. Commercial diesel and blends of diesel and n-butanol (20%: BU20 and 40%: BU40) were used for the experiments. A pilot plus main injection strategy was investigated fixing the injection pressure and fuel mass injected per stroke. Two main injection timings and different pilot-main dwell times were explored achieving for any strategy a mixing controlled combustion. Advancing the main injection start, an increase in net engine working cycle (>40%) together with a strong smoke number decrease (>80%) and NOx concentration increase (@50%) were measured for all pilot injection timings. Compared to diesel fuel, butanol induced a decrease in soot emission and an increase in net engine working area when butanol ratio increased in the blend. A noticeable increase in NOx was detected at the exhaust for BU40 with a slight effect of the dwell-time. Spectroscopic investigations confirmed the delayed auto-ignition (~60 ms) of the pilot injection for BU40 compared to diesel. The spectral features for the different fuels were comparable at the start of combustion process, but they evolved in different ways. Broadband signal caused by soot emission, was lower for BU40 than diesel. Different balance of the bands at 309 and 282 nm, due to different OH transitions, were detected between the two fuels. The ratio of these intensities was used to follow flame temperature evolution.

scholarly journals Exhaust Gas Characteristics According to the Injection Conditions in Diesel and DME Engines

2019 ◽  
Vol 9 (4) ◽  
pp. 647 ◽  
Author(s):  
Seamoon Yang ◽  
Changhee Lee
Keyword(s):  
High Pressure ◽  
Injection Pressure ◽  
Common Rail ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Pilot Injection ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Pressure Injection ◽  
High Pressure Injection

In this paper, the effect of high-pressure injection pressure on particulate matter (PM) and nitrogen oxide (NOx) emissions is discussed. Many studies have been conducted by active researchers on high-pressure engines; however, the problem of reducing PM and NOx emissions is still not solved. Therefore, in the existing diesel (compression ignition) engines, the common rail high-pressure injection system has limitations in reducing PM and NOx emissions. Accordingly, to solve the exhaust gas emission problem of a compression ignition engine, a compression ignition engine using an alternative fuel is discussed. This study was conducted to optimize the dimethyl ether (DME) engine system, which can satisfy the emission gas exhaust requirements that cannot be satisfied by the current common rail diesel compression ignition engine in terms of efficiency and exhaust gas using DME common rail compression ignition engine. Based on the results of this study on diesel and DME engines under common rail conditions, the changes in engine performance and emission characteristics of exhaust gases with respect to the injection pressure and injection rate were examined. The emission characteristics of NOx, hydrocarbons, and carbon monoxide (CO) emissions were affected by the injection pressure of pilot injection. Under these conditions, the exhaust gas characteristics were optimized when the pilot injection period and needle lift were varied.

scholarly journals Effects of Post-Injection Characteristics on the Combustion, Emission, and Performance in a Diesel-Syngas Reactivity Controlled Compression Ignition Engine

2021 ◽  
Vol 18 (3) ◽  
pp. 9006-9021
Author(s):  
M. J. Noroozi ◽  
M. Seddiq
Keyword(s):  
Carbon Monoxide ◽  
Particulate Matter ◽  
Flame Temperature ◽  
Combustion Process ◽  
Injection Pressure ◽  
Operating Conditions ◽  
Injection Timing ◽  
Post Injection ◽  
Compression Ignition Engine ◽  
Peak Point

This paper presents a numerical investigation of the separate effects of post-injection characteristics in a heavy-duty turbocharged direct injection diesel engine under pure diesel combustion (PDC) and diesel-syngas combustion (DSC) operating conditions. Converge CFD code was used coupled with a detailed n-heptane/toluene/PAH chemical kinetic mechanism (consists of 71 species and 360 reactions) for diesel-syngas dual-fuel combustion simulation. A total of 36 strategies based on the post-injection characteristics (post-injection timing, fuel quantity, spraying pressure, and main-post dwell time) on the combustion characteristics, exhaust gas emissions, and engine performance under PDC and DSC conditions were investigated. Numerical achievements revealed that 40% substitution of diesel fuel with syngas significantly decreased particulate matter emission and enhanced the indicated thermal efficiency (ITE), compared to the baseline PDC case. However, carbon monoxide noticeably increased. In addition, retarding the post-injection timing prolonged the combustion duration and also reduced the nitrogen oxides emissions and ITE. By increasing the post-injection quantity up to 15%, the combustion process deteriorated, and carbon-based emissions such as particulate matter, carbon monoxide, and unburnt hydro-carbon in the exhaust gases increased under PDC and DSC conditions. Furthermore, increasing post-injection pressure (PIP) from 1000 to 1450 bar under both PDC and DSC conditions led to higher flame temperature, and as a result, the heat release rate peak point and temperature peak point for the second combustion event increased. However, at a PIP of 1600 bar, the ITE deteriorated under PDC and DSC operating cases.

scholarly journals Assessment of late pilot injection effect in dual-fuel combustion

2020 ◽  
Vol 197 ◽  
pp. 06010
Author(s):  
Antonio Caricato ◽  
Antonio Paolo Carlucci ◽  
Antonio Ficarella ◽  
Luciano Strafella
Keyword(s):  
Injection Pressure ◽  
Dual Fuel ◽  
Injection Timing ◽  
Pilot Injection ◽  
Compression Ignition Engine ◽  
Engine Load ◽  
Pilot Fuel ◽  
Dual Fuel Combustion ◽  
Cylinder Compression ◽  
Injection Effect

In this paper, the effect of late injection on combustion and emission levels has been investigated on a single cylinder compression ignition engine operated in dual-fuel mode injecting methane along the intake duct and igniting it through a pilot fuel injected directly into the combustion chamber. During the tests, the amount of pilot fuel injected per cycle has been kept constant, while the amount of methane has been varied on three levels. Therefore, three levels of engine load have been tested, while speed has been kept constant equal to 1500rpm. Pilot injection pressure has been varied on three set points, namely 500, 1000 and 1500 bar. For each engine load and injection pressure, pilot injection timing has been swept on a very broad range of values, spanning from very advanced to very late values. The analysis of heat release rate indicates that MK-like conditions are established in dual-fuel mode with late pilot injection. In these conditions, pollutant species, and NOx levels in particular, are significantly reduced without penalization – and in several conditions with improvement – on fuel conversion efficiency.

Experimental investigation of dwell time characteristics in high-pressure double-solenoid-valve fuel injection system

2019 ◽  
Vol 233 (13) ◽  
pp. 3281-3292
Author(s):  
Dan Xu ◽  
Qing Yang ◽  
Xiaodong An ◽  
Baigang Sun ◽  
Dongwei Wu ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Injection Pressure ◽  
Solenoid Valve ◽  
Injection System ◽  
Fuel Injection System ◽  
Pilot Injection ◽  
Main Injection ◽  
Injection Interval ◽  
The Difference ◽  
Variation Rule

The double-solenoid-valve fuel injection system consists of an electronic unit pump and an electronic injector. It can realize the separate control of fuel supply and injection and has the advantages of adjusting pressure by cycle and flexible controlling of the injection rate. The interval angle between the pilot and main injection directly affects the action degree and the characteristics of two adjacent injections, affecting engine performance. This work realizes multiple injection processes on the test platform of a high-pressure double-solenoid-valve fuel injection system, with maximum injection pressure reaching 200 MPa. In this study, the interval between driven current signal of pilot injection termination and that of main injection initiation is defined as the signal interval (DT1), whereas the interval between pilot injection termination and main injection initiation is defined as the injection interval (DT2). The differences between the signal and the injection intervals are calculated, and the variation rule of the difference with respect to the signal interval is analyzed. Results show that the variation rule of the difference with the signal interval first decreases, then increases, and finally decreases. The variation rule of the delay angle from the start of needle movement to the start of fuel injection is found to be the root cause of this rule. The influence of the injection pressure on needle deformation and fuel flow rate of the nozzle results in the variation rule. In addition, the influence of the cam speed, temperature, and pipe length on the difference between the signal and injection interval is determined. This research provides guidance for an optimal control strategy of the fuel injection process.

An Experimental Study on Smoke Reduction Effect of Post Injection in Combination With Pilot Injection for a Diesel Engine

2013 ◽  
Vol 136 (4) ◽  
Author(s):  
Long Liu ◽  
Naoto Horibe ◽  
Tatsuya Komizo ◽  
Issei Tamura ◽  
Takuji Ishiyama
Keyword(s):  
Diesel Engine ◽  
Injection Pressure ◽  
Injection Timing ◽  
Nox Emissions ◽  
Pilot Injection ◽  
Post Injection ◽  
Spray Flames ◽  
Injection Quantity ◽  
Main Injection ◽  
Reduction Effect

With the universal utilization of the common-rail injection system in automotive diesel engines, the multistage injection strategies have become typical approaches to satisfy the increasingly stringent emission regulations, and especially the post injection has received considerable attention as an effective way for reducing the smoke emissions. Normally the post injection is applied in combination with the pilot injection to restrain the NOx emissions, smoke emissions, and combustion noise simultaneously, and the pilot injection condition affects the combustion process of the main injection and might affect the smoke reduction effect of the post injection. Thus this study aims at obtaining the post injection strategy to reduce smoke emissions in a diesel engine, where post injection is employed in combination with pilot injection. The experiments were performed using a single-cylinder diesel engine under various conditions of pilot and post injection with a constant load at an IMEP of 1.01 MPa, fixed speed of 1500 rpm, and NOx emissions concentration of 150 ± 5 ppm that was maintained by adjusting the EGR ratio. The injection pressure was set at 90 MPa at first, and then it was varied to 125 MPa to evaluate the effects of post injection on the smoke reduction in the case of higher injection pressure. The experimental results show that small post injection quantity with a short interval from the end of main injection causes less smoke emissions. And larger pilot injection quantity and later pilot injection timing lead to higher smoke emissions. And then, to explore and interpret the smoke emissions tendencies with varying pilot and post injection conditions, the experimental results of three-stage injection conditions were compared to those of two reference cases, which only included the pilot and main injection, and the interaction between main spray flames and post sprays was applied for analysis. Based on the comparative analysis, the larger smoke reduction effect of post injection was observed with the larger pilot injection quantity, while it is not greatly influenced by pilot injection timing. In addition, the smoke emissions can be reduced considerably by increasing the injection pressure, however the smoke reduction effect of post injection was attenuated. And all of these tendencies were able to be interpreted by considering the intensity variation of the interaction between main spray flames and post sprays.

scholarly journals Comparative Analysis of Combustion Stability of Diesel/Ethanol Utilization by Blend and Dual Fuel

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 946 ◽  
Author(s):  
Wojciech Tutak ◽  
Arkadiusz Jamrozik
Keyword(s):  
Diesel Fuel ◽  
Fuel Injection ◽  
Combustion Process ◽  
Combustion Stability ◽  
Dual Fuel ◽  
Maximum Pressure ◽  
Compression Ignition Engine ◽  
Energy Fraction ◽  
Pure Ethanol ◽  
Advantages And Disadvantages

The aim of the work is a comparison of two combustion systems of fuels with different reactivity. The first is combustion of the fuel mixture and the second is combustion in a dual-fuel engine. Diesel fuel was burned with pure ethanol. Both methods of co-firing fuels have both advantages and disadvantages. Attention was paid to the combustion stability aspect determined by COVIMEP as well as the probability density function of IMEP. It was analyzed also the spread of the maximum pressure value, the angle of the position of maximum pressure. The influence of ethanol on ignition delay time spread and end of combustion process was evaluated. The experimental investigation was conducted on 1-cylinder air cooled compression ignition engine. The test engine operated with constant rpm equal to 1500 rpm and constant angle of start of diesel fuel injection. The engine was operated with ethanol up to 50% of its energy fraction.

scholarly journals Combustion stability of dual fuel engine powered by diesel-ethanol fuels

2019 ◽  
Vol 178 (3) ◽  
pp. 155-161
Author(s):  
Łukasz NOWAK ◽  
Wojciech TUTAK
Keyword(s):  
Diesel Fuel ◽  
Combustion Process ◽  
Combustion Stability ◽  
Dual Fuel ◽  
Probability Density Distribution ◽  
Maximum Pressure ◽  
Operational Parameters ◽  
Compression Ignition Engine ◽  
Energy Fraction ◽  
The Stability

The paper presents result of combustion stability assessment of dual fuel engine. The authors analyzed results of co-combustion of diesel fuel with alcohol in terms of combustion stability. The comparative analysis of both the operational parameters of the engine and the IMEP, as the parameters determining the stability of the combustion process, were carried out. It was analyzed, among others values of the COVIMEP coefficient, the spread of the maximum pressure value, the angle of the position of maximum pressure and the probability density distribution of the IMEP. The experimental investigation was conducted on 1-cylinder air cooled compression ignition engine. The test engine operated with constant rpm equal to 1500 rpm and constant angle of start of diesel fuel injection. The engine was operat-ed with ethanol up to 50% of its energy fraction. The influence of ethanol on ignition delay time spread and end of combustion process was evaluated. It turns out that the share of ethanol does not adversely affect the stability of ignition..

scholarly journals Analysis of Engine Parameters at Using Diesel-LPG and Diesel-CNG Mixture in Compression-ignition Engine

2014 ◽  
Vol 62 (1) ◽  
pp. 125-130 ◽  
Author(s):  
Michal Jukl ◽  
Petr Dostál ◽  
Jiří Čupera
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Common Rail ◽  
Measurement Equipment ◽  
Compression Ignition ◽  
Performance Parameters ◽  
Compression Ignition Engine ◽  
Positive Effect

This work is aimed on influence of diesel engine parameters that is used with mixture of gas and diesel fuel. The first part of the article describes diesel fuel systems where small part of diesel fuel is replaced by LPG or CNG fuel. These systems are often called as Diesel-Gas systems. Next part of the article focuses on tested car and measurement equipment. Measurement was performed by common-rail diesel engine in Fiat Doblň. Tests were carried out in laboratories of the Department of Engineering and Automobile Transport at the Mendel University in Brno. They were observed changes between emissions of used fuels – diesel without addition of gas, diesel + LPG and diesel + CNG mixture. It was found that that the addition of gas had positive effect on the performance parameters and emissions.

scholarly journals RME CO-COMBUSTION WITH HYDROGEN IN COMPRESSION IGNITION ENGINE: PERFORMANCE, EFFICIENCY AND EMISSIONS / SLĖGINIO UŽDEGIMO VARIKLIO ENERGINIŲ, EFEKTYVUMO IR DEGINIŲ EMISIJOS RODIKLIŲ TYRIMAS NAUDOJANT RAPSŲ METILESTERĮ IR VANDENILĮ

2018 ◽  
Vol 10 (0) ◽  
pp. 1-9
Author(s):  
Romualdas Juknelevičius
Keyword(s):  
Combustion Process ◽  
Engine Performance ◽  
Fuel Mixture ◽  
Common Rail ◽  
Injection System ◽  
Intake Manifold ◽  
Compression Ignition Engine ◽  
Common Rail Injection System ◽  
Wide Range ◽  
The Rich

The article presents the test results of the single cylinder CI engine with common rail injection system operating on biofuel – Rapeseed Methyl Ester with addition supply of hydrogen. The purpose of this investigation was to examine the influence of the hydrogen addition to the biofuel on combustion phases, engine performance, efficiency, and exhaust emissions. HES was changed within the range from 0 to 44%. Hydrogen was injected into the intake manifold, where it created homogeneous mixture with air. Tests were performed at both fixed and optimal injection timings at low, medium and nominal engine load. After analysis of the engine bench tests and simulation with AVL BOOST software, it was observed that lean hydrogen – RME mixture does not support the flame propagation and efficient combustion. While at the rich fuel mixture and with increasing hydrogen fraction, the combustion intensity concentrate at the beginning of the combustion process and shortened the ignition delay phase. AVL BOOST simulation performed within the wide range of HES (16–80%) revealed that combustion intensity moves to the beginning of combustion with increase of HES. Decrease of CO, CO2 and smoke opacity was observed with increase of hydrogen amounts to the engine. However, increase of the NO concentration in the engine exhaust gases was observed. Santrauka Straipsnyje pateikti tyrimo rezultatai, gauti atlikus bandymą vieno cilindro slėginio uždegimo variklyje su biodegalais – rapsų metilesterį (RME) ir vandenilį. Biodegalai įpurškiami akumuliatorine įpurškimo sistema „Common rail“. Šio tyrimo tikslas – ištirti, kaip vandenilis veikia biodegalų degimą, variklio veikimą, jo efektyvumą ir deginių susidarymą. Vandenilio energinė dalis degimo mišinyje buvo keičiama nuo 0 iki 44 %. Vandenilis buvo tiekiamas įsiurbimo fazės metu įsiurbimo kanalu į degimo kamerą, kurioje jis, susimaišęs su oru, sudaro homogeninį mišinį. Bandymai buvo atliekami nekeičiant įpurškimo kampo, nustačius optimalų įpurškimo kampą esant žemai, vidutinei ir nominaliai variklio apkrovai. Išnagrinėjus variklio bandymų rezultatus ir sumodeliavu AVL BOOST programa, buvo pastebėta, kad, esant liesam vandenilio ir RME mišiniui, liepsnos plitimas yra lėtas, mišinys dega neveiksmingai. Tačiau riebus degalų mišinys ir padidinta vandenilio energijos dalis užtikrina degimo intensyvumą degimo proceso pradžioje ir sutrumpina uždegimo gaišties trukmę. AVL BOOST modeliavimas, atliktas plačiu vandenilio energijos dalies diapazonu (16–80 %), patvirtino teiginį, kad degimas tampa intensyvesnis degimo pradžioje dėl padidinto vandenilio kiekio. Didinant vandenilio kiekį, buvo pastebėta, kad išmetamosiose dujose sumažėjo CO, CO2 ir kietųjų dalelių, tačiau padidėjo NO koncentracija.

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