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.

Performance Analysis of an Otto Engine with Ethanol and Gasoline Fuels

2011 ◽  
Vol 110-116 ◽  
pp. 267-272 ◽  
Author(s):  
Rahim Ebrahim
Keyword(s):  
Performance Analysis ◽  
Compression Ratio ◽  
Power Output ◽  
Thermal Efficiency ◽  
Alternative Fuels ◽  
Gasoline Engine ◽  
Maximum Power ◽  
Comparative Performance ◽  
Engine Operation ◽  
Maximum Power Output

Energy conservation and its efficient use are nowadays a major issue. The evident reduction in oil reserves combined with the increase in its price, as well as the need for ‘cleaner’ fuels, have led in the past years to an increasing interest and research in the field of alternative fuels for spark ignition engines propulsion. Also, there are interesting to increase the technical focus on conventional cycles for making them more optimum in terms of performance. In this study, a comparative performance analysis and optimisation have been performed for irreversible Otto cycle with ethanol, methanol and gasoline fuels. The results show that the maximum power output, the working range of the cycle, the optimal power output corresponding to maximum thermal efficiency, the optimal thermal efficiency corresponding to maximum power output increase, the compression ratio at the maximum power output and the compression ratio at the maximum thermal efficiency when ethanol-engine operation is changed to gasoline-engine operation. The results obtained in this work can help us to understand how the power output and thermal efficiency are influenced by ethanol and gasoline fuels in an Otto engine.

Reconstructing Cylinder Pressure of a Spark-Ignition Engine for Heat Transfer and Heat Release Analyses

2004 ◽  
Author(s):  
Pin Zeng ◽  
Robert G. Prucka ◽  
Zoran S. Filipi ◽  
Dennis N. Assanis
Keyword(s):  
Heat Transfer ◽  
Heat Release ◽  
Engine Speed ◽  
Gasoline Engine ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Cylinder Pressure ◽  
Spark Timing ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel

This paper proposes a technique for reconstructing the cylinder pressure traces of a spark-ignition engine based on three inputs: spark-timing, speed and load. This method is an extension of previous work for reconstructing cylinder pressure in a heavy-duty diesel engine [1]. The previous study utilized only two inputs for cylinder pressure reconstruction, e.g. engine speed and load, hence implying optimal combustion phasing. The new method adds one more input to allow reconstruction of pressure traces from cycles with combustion phasing altered based on emissions or knock constraints. The method was applied to a 4-cylinder, 2.4-liter DaimlerChrysler gasoline engine. Comparisons between measured and reconstructed cylinder pressure traces demonstrate that the method is applicable over the majority of the gasoline engine operating range. Reconstructed cylinder pressure traces have also been used to carry out engine heat transfer and heat release analyses. Problems associated with the application of this method to gasoline engine are also discussed.

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%.

Research of NOx Emissions Characteristic of Engine Fuelled with M40

2011 ◽  
Vol 382 ◽  
pp. 22-25
Author(s):  
Xin Guang Li ◽  
Bing Yuan Han ◽  
Rong Hai Yang
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Simulation Model ◽  
Compression Ratio ◽  
Gasoline Engine ◽  
Volume Ratio ◽  
Nox Emissions ◽  
Cylinder Pressure ◽  
Variable Parameters ◽  
Vehicle Engine

A numerical simulation model for gasoline engine was established by GT-POWER in order to study the NOx emissions characteristic of vehicle engine fuelled with M40 (the methanol and the gasoline in volume ratio 40∶60) and was validated by Experimental data. Based on the model, the variable parameters study including air-fuel radio, compression radio and ignition advance angle were carried out. The model results showed that the compression radio and the air-fuel radio played an important role during the NOx emissions characteristic. There is a significant improvement of the NOx emissions with the compression ratio increases. The cylinder pressure increased with the improvement of the compression ratio brought out the NOx emissions rise. With the improvement of the air-fuel ratio, NOx emissions increased first and then decreased. A larger ignition advance angle can increase the pressure and the temperature of the cylinder.

Application of Over-Expansion Cycle to a Larger Gasoline Engine With Late-Closing of Intake Valves

2002 ◽  
Author(s):  
Seiichi Shiga ◽  
Kenji Nishida ◽  
Shizuo Yagi ◽  
Youichi Miyashita ◽  
Yoshiharu Yuzawa ◽  
...  
Keyword(s):  
Compression Ratio ◽  
Thermal Efficiency ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Mechanical Efficiency ◽  
Expansion Ratio ◽  
Brake Thermal Efficiency ◽  
Gasoline Engines ◽  
Cylinder Test ◽  
Test Engine

This paper presents further investigation into the effect of over-expansion cycle with late-closing of intake valves on the engine performance in gasoline engines. A larger single-cylinder test engine with the stroke volume of 650 cc was used with four kinds of expansion ratio (geometrical compression ratio) from 10 to 25 and four sets of intake valve closure (I.V.C.) timings from 0 to 110 deg C.A. ABDC. Late-closing has an effect of decreasing the pumping work due to the reduction of intake vacuum, althogh higher expansion ratio increases the friction work due to the average cylinder pressure level. Combining the higher expansion ratio with the late-closing determines the mechanical efficiency on the basis of these two contrastive effects. The indicated thermal efficiency is mostly determined by the expansion ratio and little affected by the nominal compression ratio. The value of the indicated thermal efficiency reaches to 48% at most which is almost comparable with the value of diesel engines. The improvement of both indicated and brake thermal efficiency reaches to 16% which is much higher than ever reported by the authors. A simple thermodynamic calculation could successfully explain the behavior of the indicated thermal efficiency. The brake thermal efficiency could also be improved due to the increase in both mechanical and indicated efficiencies.

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.

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.

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 Methodology for Optical Engine Characterization by Means of the Combination of Experimental and Modeling Techniques

2018 ◽  
Vol 8 (12) ◽  
pp. 2571 ◽  
Author(s):  
José Pastor ◽  
Pablo Olmeda ◽  
Jaime Martín ◽  
Felipe Lewiski
Keyword(s):  
Heat Transfer ◽  
Heat Release ◽  
Thermodynamic Analysis ◽  
Compression Ratio ◽  
Combustion Process ◽  
Pollutant Emissions ◽  
Transfer Model ◽  
Special Importance ◽  
Cylinder Pressure ◽  
Optical Engine

Optical engines allow for the direct visualization of the phenomena taking place in the combustion chamber and the application of optical techniques for combustion analysis, which makes them invaluable tools for the study of advanced combustion modes aimed at reducing pollutant emissions and increasing efficiency. An accurate thermodynamic analysis of the engine performance based on the in-cylinder pressure provides key information regarding the gas properties, the heat release, and the mixing conditions. If, in addition, optical access to the combustion process is provided, a deeper understanding of the phenomena can be derived, allowing the complete assessment of new injection-combustion strategies to be depicted. However, the optical engine is only useful for this purpose if the geometry, heat transfer, and thermodynamic conditions of the optical engine can mimic those of a real engine. Consequently, a reliable thermodynamic analysis of the optical engine itself is mandatory to accurately determine a number of uncertain parameters among which the effective compression ratio and heat transfer coefficient are of special importance. In the case of optical engines, the determination of such uncertainties is especially challenging due to their intrinsic features regarding the large mechanical deformations of the elongated piston caused by the pressure, and the specific thermal characteristics that affect the in-cylinder conditions. In this work, a specific methodology for optical engine characterization based on the combination of experimental measurements and in-cylinder 0D modeling is presented. On one hand, the method takes into account the experimental deformations measured with a high-speed camera in order to determine the effective compression ratio; on the other hand, the 0D thermodynamic analysis is used to calibrate the heat transfer model and to determine the rest of the uncertainties based on the minimization of the heat release rate residual in motored conditions. The method has been demonstrated to be reliable to characterize the optical engine, providing an accurate in-cylinder volume trace with a maximum deformation of 0.5 mm at 80 bar of peak pressure and good experimental vs. simulated in-cylinder pressure fitting.

Study of Combustion and Emission Characteristics of Gasoline Engine with Miller Cycle

2014 ◽  
Vol 960-961 ◽  
pp. 1411-1415 ◽  
Author(s):  
Jian Wu ◽  
Wei Fan ◽  
Yang Hua ◽  
Yun Long Li ◽  
Shao Zhe Zhang ◽  
...  
Keyword(s):  
Heat Release ◽  
Compression Ratio ◽  
Gasoline Engine ◽  
Control Technology ◽  
Miller Cycle ◽  
High Compression Ratio ◽  
Combustion Heat ◽  
Geometry Compression ◽  
Cam Profile ◽  
Hc Emissions

On the basis of original engine, high compression ratio miller cycle can be realized, through perfecting the inlet cam profile, using higher geometry compression ratio, combining VVT control technology. The results indicate that the miller cycle achieved by VVT control technology can reduce pumping loss, and improve the effect utilization of energy. The combustion heat release rate is lower than the original engine, and combustion heat release are mainly concentrated on TDC later, lower the burning temperature. Compared with the original engine, NOX emissions decrease significantly, but CO and HC emissions increase somewhat.

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