Experimental studies on the combustion characteristics and performance of a naturally aspirated, direct injection engine fuelled with a liquid petroleum gas/diesel blend

2005 ◽  
Vol 219 (2) ◽  
pp. 253-261 ◽  
Author(s):  
Qi Donghui ◽  
Zhou Longbao ◽  
Liu Shenghua
Keyword(s):  
Heat Release ◽  
Fuel Consumption ◽  
Power Output ◽  
Ignition Delay ◽  
Pressure Rise ◽  
Combustion Characteristics ◽  
Cylinder Pressure ◽  
Mixing Ratio ◽  
Peak Rate ◽  
Blend Fuel

This paper studies the combustion characteristics and performances of a LPG/diesel blend-fuel engine; the influences of mixing ratio of LPG in diesel on the ignition timing, in-cylinder pressure, heat-release rate, specific fuel consumption, power output, and exhaust emissions have been identified. The results indicate that the ignition delay of blend fuel was obviously longer than that of diesel and the higher the mixing ratio of LPG in diesel, the longer the ignition delay. When the mixing ratio of LPG in diesel was 10 per cent, the peak in-cylinder gas pressure and the peak rate of pressure rise were slightly higher than those of diesel, and the corresponding crank angles at which the peak values occurred were almost the same as those of diesel. When the mixing ratio was 30 per cent, the peak in-cylinder pressure and the peak rate of pressure rise were lower than those of diesel, and the corresponding crank angles were retarded. With the increasing of mixing ratio of LPG in diesel, the peak rate of heat release increased and the corresponding crank angles were retarded. The equivalent specific fuel consumption of L10 was the same as that of diesel, but that of L30 was slight higher. The power output of the diesel engine was higher than those of L10 and L30 at speed characteristic of full load, especially at high engine speed. With the increasing of mixing ratio, the smoke emissions and NOx emissions were greatly reduced, and CO emissions decreased too, but HC emissions slightly increased.

Effect of Mahua Biodiesel Blends on the Combustion Characteristics of Direct Injection CI Engine at Various Compression Ratios

2015 ◽  
Vol 813-814 ◽  
pp. 824-829
Author(s):  
Ramani Vagesh Shangar ◽  
Venkatesan Hariram
Keyword(s):  
Heat Release ◽  
Compression Ratio ◽  
Ignition Delay ◽  
Direct Injection ◽  
Combustion Characteristics ◽  
Cylinder Pressure ◽  
Biodiesel Blends ◽  
Peak Cylinder Pressure ◽  
Ci Engine ◽  
Mahua Biodiesel

In the current study, combustion characteristics were evaluated using mahua biodiesel blends at different compression ratios on a direct injection CI engine. Non edible mahua oil was transesterified into biodiesel by two stage technique. Combustion parameters were evaluated for B5, B10 and B20 blends of mahua biodiesel with diesel and they were compared with straight diesel at compression ratios of 16, 17 and 18.Compression ratio was varied without altering the combustion chamber geometry and the static spill timing was set to 23° bTDC. Parameters like In cylinder pressure, heat release rate, rate of pressure rise and cumulative heat release were evaluated in this study at 100% engine loading conditions. Higher peak cylinder pressure and heat release was observed at higher compression ratios. The ignition delay of the blends were slightly higher compared to diesel at all CR tested. Peak cylinder pressure of the blends was slightly higher at CR 18. The ignition delay was also observed to be lower at higher compression ratio. The peak pressure was observed closer to TDC at higher compression ratios for all fuels tested.

Effects of λ on the Combustion Characteristics of HCCI Engine Fueled with N-Butanol

2015 ◽  
Vol 1092-1093 ◽  
pp. 508-511
Author(s):  
Jia Wang Zhou ◽  
Chun Hua Zhang ◽  
Gang Li ◽  
Ye Chun Shen
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Combustion Engine ◽  
Pressure Rise ◽  
Combustion Characteristics ◽  
Cylinder Pressure ◽  
Maximum Heat ◽  
Hcci Engine ◽  
Combustion Duration

The combustion characteristics of an HCCI engine fueled with n-butanol were investigated on a modified two-cylinder, four stoke diesel engine. The experiments were conducted on the HCCI engine with λ of 2.0, 2.5 and 3.0, and the intake air temperature and engine speed were kept at 140 °C and 1000rpm, respectively. Effects of λ on combustion characteristics including in-cylinder pressure rise rate, heat release rate, CA05 and combustion duration of HCCI combustion engine are discussed in details based on the recorded in-cylinder pressure. The results indicate that in-cylinder pressure and the rate of pressure rise both decrease with the increase of λ, the maximum heat release rate also decreases with the increase of λ but occurs at late crank angles. In addition, as λ increases, the combustion phasing retards and combustion duration becomes longer.

Emission and Combustion Characteristics of Biodiesel (Jatropha Curcas) Blends in a Medium Duty IDI Transportation Engine

2007 ◽  
Author(s):  
Harish Kumar Gangwar ◽  
Avinash Kumar Agarwal
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Vegetable Oils ◽  
Import Substitution ◽  
Pressure Rise ◽  
Careful Analysis ◽  
Combustion Characteristics ◽  
Experimental Investigations ◽  
Cylinder Pressure ◽  
Biodiesel Blends

Vegetable oils, due to their agricultural origin, are able to reduce net carbon-di-oxide emissions to the atmosphere along with import substitution of petroleum products. However, several operational and durability problems in using straight vegetable oils as CI engine fuels are reported in the literature, which are because of their higher viscosity and low volatility compared to mineral diesel. In the present research, experiment were designed to study the effect of lowering Jatropha oil’s viscosity by transesterification and thereby eliminating adverse effects on combustion characteristics of the engine. In the present experimental research, Jatropha methyl ester is produced by transesterification of jatropha oil using methanol in presence of basic catalyst (Sodium hydroxide). Experimental investigations have been carried out to examine the combustion characteristics of in an indirect injection (IDI) transportation diesel engine running with diesel, biodiesel and its blends with diesel. Engine tests were performed at different engine loads ranging from no load to rated (100%) load at fixed engine speed (2000 rpm). A careful analysis of cylinder pressure rise, instantaneous heat release and cumulative heat release was carried out. All test fuels exhibited similar combustion stages as diesel however biodiesel and its blends showed earlier start of combustion and lower heat release during premixed combustion phase at all engine load. Maximum cylinder pressure reduces as the fraction of biodiesel increases in the blend and at higher engine loads, the crank angle position of peak cylinder pressure for biodiesel blends shifted away from top dead center. The maximum rate of pressure rise was found to be higher for diesel at higher engine loads however total combustion duration was higher for biodiesel blends.

Renewable Fuel Performance in a Legacy Military Diesel Engine

2011 ◽  
Author(s):  
Leonard J. Hamilton ◽  
Sherry A. Williams ◽  
Richard A. Kamin ◽  
Matthew A. Carr ◽  
Patrick A. Caton ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Vegetable Oil ◽  
Ignition Delay ◽  
Jet Fuel ◽  
Combustion Characteristics ◽  
Load Range ◽  
Engine Torque ◽  
Brake Torque ◽  
Renewable Fuel

A new Hydrotreated Vegetable Oil (HVO) from the camelina plant has been processed into a Hydrotreated Renewable Jet (HRJ) fuel. This HRJ fuel was tested in an extensively instrumented legacy military diesel engine along with conventional Navy jet fuel JP-5. Both fuels performed well across the speed-load range of this HMMWV engine. The high cetane value of the HRJ leads to modestly shorter ignition delay. The longer ignition delay of JP-5 delivers shorter overall combustion durations, with associated higher indicated engine torque levels. Both brake torque and brake fuel consumption are better with conventional JP-5 by up to ten percent, due to more ideal combustion characteristics.

Combustion Characteristics of Single Cylinder Diesel Engine Fueled with Blends of Thumba Biodiesel as an Alternative Fuel

2019 ◽  
Vol 969 ◽  
pp. 451-460
Author(s):  
Manpreet Singh ◽  
Mohd Yunus Sheikh ◽  
Dharmendra Singh ◽  
P. Nageswara Rao
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Heat Release Rate ◽  
Diesel Fuel ◽  
Release Rate ◽  
Mass Fraction ◽  
Pressure Rise ◽  
Cylinder Pressure ◽  
Gas Temperature ◽  
Edible Vegetable Oil

The rapid rise in energy requirement and problem regarding atmosphere pollutions, renewable biofuels are the better alternative choice for the internal combustion engine to partially or totally replace the pollutant petroleum fuel. In the present work, thumba (Citrullus colocynthis) non-edible vegetable oil is used for the production of biodiesel and examine its possibility as diesel engine fuel. Transesterification process is used to produce biodiesel from thumba non-edible vegetable oil. Thumba biodiesel (TBD) is used to prepare five different volume concentration (blends) with neat diesel (D100), such as TBD5, TBD15, TBD25, TBD35 and TBD45 to run a single cylinder diesel engine. The diesel engine's combustion parameter such as in-cylinder pressure, rate of pressure rise, net heat release rate, cumulative heat release, mean gas temperature, and mass fraction burnt analyzed through graphs and compared all thumba biodiesel blends result with neat diesel fuel. The mass fraction burnt start earlier for thumba biodiesel blends compared to diesel fuel because of less ignition delay while peak in-cylinder pressure, maximum rate of pressure rise, maximum net heat release rate, maximum cumulative heat release, and maximum mean gas temperature has found decreased results up to 1.93%, 5.53%, 4.11%, 4.65%, and 1.73% respectively for thumba biodiesel.

Study on the Combustion Characteristics of the Engine Fueled with DME-Diesel Blends

2014 ◽  
Vol 953-954 ◽  
pp. 1381-1385
Author(s):  
Wei Li ◽  
Yun Peng Li ◽  
Fan Bin Li
Keyword(s):  
Heat Release ◽  
Pressure Rise ◽  
Mechanical Efficiency ◽  
Diesel Oil ◽  
Cylinder Pressure ◽  
Mass Ratio ◽  
Combustion Duration ◽  
Crank Angle ◽  
Maximum Combustion Temperature ◽  
Stroke Engine

To further study the performance of the engine fueled with DME-diesel blends, the indicator diagrams of a two-cylinder four-stroke engine are recorded at 1700r/min and 2300r/min under different load, the heat release rate and the rate of pressure rise are calculated. The results show that: when fueled the engine with D20 blend (Mass ratio of DME and diesel oil is 2:10) and optimizing the fuel supply advance angle, the maximum cylinder pressure decreases by 10% averagely and its corresponding crank angle delays 2°CA, the maximum rate of pressure rise is relatively lowers about 20%, the beginning of heat release delays，but combustion duration do not extend, and the centroid of heat release curves is closer to TDC (Top Dead Center), maximum combustion temperature drops 70-90K. These results indicate that the mechanical efficiency will be improved and, NOx emissions and mechanical noise will be reduced when an engine fueled with DME-diesel blends.

Effects of Different LPG Fuel Systems on Performances of Variable Compression Ratio Single Cylinder Engine

2002 ◽  
Author(s):  
G. H. Choi ◽  
J. H. Kim ◽  
Christian Homeyer
Keyword(s):  
Liquid Phase ◽  
Heat Release ◽  
Compression Ratio ◽  
Power Output ◽  
Alternative Fuels ◽  
Gasoline Engine ◽  
Cylinder Pressure ◽  
Maximum Heat ◽  
Spark Timing ◽  
Test Engine

Since the early 20th century, most ground vehicles are driven with gasoline and diesel. The degradation of the environment affects human on earth unless the quality of the air is improved. One of the alternative fuels, LPG, is potentially capable of lowering vehicular emissions when compared to gasoline or diesel. There is a penalty in power output resulting from the use of LPG because the engine can induce less amount of air with Mixer system comparing with gasoline engine. Currently, the liquid-phase LPG is injected into the intake port of the engine, the fuel vaporizes enroute to the combustion chamber. Therefore, the performance and combustion processes of the tested engine are investigated with different LPG fuel systems. The test engine was developed and named heavy-duty VACRE. The test engine for this work operates 1400rpm with MBT conditions. The major conclusions of the work include; 1) The power output of LPi system with liquid-phase is approximately 17% higher than that of vapor-phase Mixer system due to increases of volumetric efficiency. And the MBT spark timing of LPi system is approximately 25% more advanced than that of Mixer system at λ value 1.0; 2) The LPi system shows both the maximum heat release rate and the cumulative heat release to be approximately 20% higher than the Mixer system; 3) Maximum cylinder pressure decrease with increase of compression ratio and a point of maximum cylinder pressure is delayed with high compression ratio.

Influence of piston bowl geometry on combustion and emission characteristics

2019 ◽  
Vol 233 (5) ◽  
pp. 576-587 ◽  
Author(s):  
Ramazan Şener ◽  
Mehmed R Özdemir ◽  
Murat U Yangaz
Keyword(s):  
Heat Release ◽  
Renewable Energy Sources ◽  
Combustion Characteristics ◽  
Emission Rates ◽  
Cylinder Pressure ◽  
Compression Ignition Engine ◽  
Piston Bowl ◽  
Crank Angle ◽  
Rate Of Heat Release ◽  
Exhaust Valves

Together with the global energy concerns, the norms are getting stringent to prevent the emission threat. There are on-going studies on systems working with both fossil and renewable energy sources aiming to create more efficient and less emissive processes and devices. Accordingly, a set of numerical simulations was performed to examine the effect of the bowl shape of a piston on the performance behaviour, emission rates and combustion characteristics in a four-cylinder, four strokes, water-cooled compression ignition engine using n-heptane (C7H16) as fuel. Six different piston bowl geometries, five from the literature and proposed one, were utilized having different length-to-diameter ratio, curvature and sidewall radius. The study was conducted at 1750 r/min engine speed and a constant compression ratio with a full performance condition. The intake and exhaust valves have been considered as closed during the analysis to provide the variation of crank angle from 300 CA to 495 CA. The results showed that the piston bowl geometry has a significant impact on the rate of heat release, in-cylinder pressure, in-cylinder temperature, and emission trends in the engine. Among the piston bowl geometries studied, design DE and design DF exhibited better combustion characteristics and relatively lower emission trends compared to other designs. The observed rate of heat release, in-cylinder pressure and in-cylinder temperature magnitudes of these two geometries was higher in comparison to other geometries. Moreover, the trade-off for NOx emission was also observed higher for these piston bowl designs.

Effects of Emulsified Fuel on Combustion in a Four-Stroke Diesel Engine

1991 ◽  
Vol 35 (04) ◽  
pp. 356-363
Author(s):  
James A. Harbach ◽  
Vito Agosta
Keyword(s):  
Standard Deviation ◽  
Fuel Consumption ◽  
Diesel Fuel ◽  
Pressure Rise ◽  
Fuel Oil ◽  
Cylinder Pressure ◽  
Commercial Practice ◽  
Emulsified Fuel ◽  
Peak Cylinder Pressure ◽  
Oil Emulsions

While the use of emulsified fuel in diesel engines has been an area of much research interest in recent years, the promising results reported in laboratories have not been easy to reproduce in commercial practice. Many of these studies have only measured external effects such as fuel consumption and exhaust emissions. A single-cylinder research engine was operated with water/diesel fuel oil and hydrous ethanol/diesel fuel oil emulsions of varying percentages. Crank angle, cylinder pressure and injector lift were recorded electronically over 50 engine cycles, permitting calculation of the mean and standard deviation of key combustion parameters. The results showed decreased fuel consumption and increased ignition delay, peak cylinder pressure and maximum cylinder pressure rise rate for emulsion operation. While the standard deviation data showed little change in cycle-to-cycle variation for wateremulsion operation, increases of over 200 percent were measured for operation at ethanol amounts over 20 percent.

scholarly journals Numerical Investigation of Combustion Characteristics of a Wave Rotor Combustor Based on a Reduced Reaction Mechanism of Ethylene

2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
Jianzhong Li ◽  
Li Yuan ◽  
Wei Li ◽  
Kaichen Zhang
Keyword(s):  
Reaction Mechanism ◽  
Flame Propagation ◽  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Pressure Rise ◽  
Combustion Characteristics ◽  
Wave Rotor ◽  
Elementary Reactions ◽  
Coupling Time

To improve simulations of the flame and pressure wave propagation process and investigate the combustion characteristics of a wave rotor combustor (WRC), direct relation graphs with error propagation (DRGEP), quasi-steady-state assumption (QSSA), and sensitivity analysis were used to establish a reduced reaction mechanism comprised of 23 species and 55 elementary reactions, based on the LLNL N-Butane mechanism. The reduced reaction mechanism of ethylene was combined with an eddy dissipation concept (EDC) model to simulate the flame propagation characteristics in a simplified WRC channel. The effects of spoilers with different blockage ratios and hot-jets of different species on combustion characteristics of flame propagation and pressure rise in the WRC channel were investigated. When the heated inert air was used as hot-jet, the ignition delay time of WRC would increase, which indicated that the activity of the burned gas from the hot-jet igniter would affect the ignition delay time. The spoiler facilitates the coupling of flame and shock waves to reduce the coupling time and distance. With the blockage ratio of the spoiler increasing, the coupling time and distance would be reduced.

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