Effect of the altitude on the combustion characteristics of a low-compression-ratio diesel engine during the start-up process

2016 ◽  
Vol 231 (13) ◽  
pp. 1838-1847 ◽  
Author(s):  
Ze-chao Kan ◽  
Zhi-yuan Hu ◽  
Di-ming Lou ◽  
Zhi-yi Cao ◽  
Jie Cao
Keyword(s):  
Diesel Engine ◽  
Compression Ratio ◽  
Peak Pressure ◽  
Direct Injection ◽  
Test System ◽  
Combustion Characteristics ◽  
Indicated Mean Effective Pressure ◽  
Start Up ◽  
Combustion Duration ◽  
Intake Pressure

One of the ways to meet future emission standards for cars and to limit the peak pressure of a heavy-duty, highly supercharged diesel engine is to reduce the compression ratio. Nevertheless, complications appear because stringent limitations to a reduction in the diesel compression ratio are the start-up requirements, in particular at high altitudes. An experimental study was conducted on the effect of the altitude on the combustion characteristics during the start-up process of a direct-injection midspeed intercooled turbocharged diesel engine with a compression ratio of 14.25:1. Specialized testing was conducted on the low-compression-ratio diesel engine, the intake pressure and the exhaust pressure of which were controlled by a plateau simulation test system to simulate the conditions at altitudes of 0 m, 1000 m, 2000 m, 3000 m, 3750 m and 4500 m. The results indicated that the pressure in the cylinder was lower during the cranking period as the altitude increased and that this caused the ignition operation to become difficult at altitudes above 3000 m. The combustion characteristics are significantly impacted by altitudes above 2000 m. At an altitude of 0–1000 m, the curve pattern of the cycle cylinder pressure had mainly a single peak during the start-up period. When the altitude increased to 2000 m, twin peaks and afterburn appeared in the cycles. Misfire appeared during the start-up period when the altitude increased to 3000 m, the combustion instability increased and the average indicated mean effective pressure decreased rapidly. When the altitude increases, the cycle-to-cycle variations in the peak pressure increased during idle, the ignition and the crank angle position at 50% of the cumulative heat release rate were delayed and the combustion duration was extended.

Investigating the Effect of Utilizing New Induction Manifold Designs on the Combustion Characteristics and Emissions of a Direct Injection Diesel Engine

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Mohamed A. Bassiony ◽  
Abdellatif M. Sadiq ◽  
Mohammed T. Gergawy ◽  
Samer F. Ahmed ◽  
Saud A. Ghani
Keyword(s):  
Diesel Engine ◽  
Peak Pressure ◽  
Direct Injection ◽  
Three Dimensional ◽  
Engine Performance ◽  
Combustion Characteristics ◽  
Maximum Pressure ◽  
Performance And Emissions ◽  
Di Diesel Engine ◽  
Dynamics Simulations

New induction manifold designs have been developed in this work to enhance the turbulence intensity and improve the mixing quality inside diesel engine cylinders. These new designs employ a spiral-helical shape with three different helical diameters (1D, 2D, 3D; where D is the inner diameter of the manifold) and three port outlet angles: 0 deg, 30 deg, and 60 deg. The new manifolds have been manufactured using three-dimensional printing technique. Computational fluid dynamics simulations have been conducted to estimate the turbulent kinetic energy (TKE) and the induction swirl generated by these new designs. The combustion characteristics that include the maximum pressure raise rate (dP/dθ) and the peak pressure inside the cylinder have been measured for a direct injection (DI) diesel engine utilizing these new manifold designs. In addition, engine performance and emissions have also been evaluated and compared with those of the normal manifold of the engine. It was found that the new manifolds with 1D helical diameter produce a high TKE and a reasonably strong induction swirl, while the ones with 2D and 3D generate lower TKEs and higher induction swirls than those of 1D. Therefore, dP/dθ and peak pressure were the highest with manifolds 1D, in particular manifold m (D, 30). Moreover, this manifold has provided the lowest fuel consumption with the engine load by about 28% reduction in comparison with the normal manifold. For engine emissions, m (D, 30) manifold has generated the lowest CO, SO2, and smoke emissions compared with the normal and other new manifolds as well, while the NO emission was the highest with this manifold.

Experimental Investigation of Combustion Characteristics of a Single Cylinder Diesel Engine at Altitude

2021 ◽  
pp. 1-21
Author(s):  
Zhentao Liu ◽  
Jinlong Liu
Keyword(s):  
Diesel Engine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Combustion Characteristics ◽  
Atmospheric Conditions ◽  
Single Cylinder ◽  
Combustion Duration ◽  
Rise Rate ◽  
Heavy Duty Diesel ◽  
Intake Pressure

Abstract Concern over the change of atmospheric conditions at high altitudes prompted interests in the deteriorated efficiency and emissions from heavy-duty diesel engines. This study utilized a single-cylinder, four stroke, direct injected diesel engine to experimentally investigate the altitude effects on combustion characteristics. High altitude operations were simulated via reducing the intake pressure but maintaining constant engine speed and torque. The results suggested reduced in-cylinder pressure but increased temperature as altitude rose. The combustion analysis indicated a slight longer ignition delay, raising and retarding the pressure rise rate and energy release rate in the premixed combustion process. A smaller excess air ratio contributed to combustion deterioration, reflected from a retarded end of combustion, a longer combustion duration, a reduced thermal efficiency, and an increased level of incomplete combustion. However, the phasing and combustion profile were not significantly impacted, when the altitude was elevated from sea level to 2000m, at least for the engine and conditions investigated in this study. Consequently, it is not necessary to adjust the engine ECU when operated in the U.S., considering that the mean elevations of most states are lower than 2000m.

PREDICTION OF EMISSIONS USING COMBUSTION PARAMETERS IN A DIESEL ENGINE THROUGH FUZZY LOGIC TECHNIQUES

2009 ◽  
Vol 08 (02) ◽  
pp. 195-207 ◽  
Author(s):  
N. BOSE ◽  
N. SENTHIL KUMAR
Keyword(s):  
Fuzzy Logic ◽  
Diesel Engine ◽  
Peak Pressure ◽  
Oxides Of Nitrogen ◽  
Indicated Mean Effective Pressure ◽  
Combustion Duration ◽  
Present Generation ◽  
Emission Regulations ◽  
Vehicle Pollution ◽  
Load Peak

The present generation faces a major problem due to pollution. The pollution from diesel engines contributes to nearly 33% of the total atmospheric on-road vehicle pollution. Diesel engine contributes more smoke and oxides of nitrogen (NOx) which are harmful to the health and environment. Preventive steps could be taken if these emissions are predicted. In this paper, the prediction of smoke and NOx has been attempted through fuzzy logic techniques. Using fuzzy logic, intermediate values could be defined between conventional evaluations. The combustion parameters considered for prediction of emissions are load, peak pressure, indicated mean effective pressure, combustion duration, and ignition delay. Based on the engine system, rules have been framed. The pollutants NOx and smoke are the output parameters. On comparison, the actual experimental readings and the values through fuzzy logic show a good correlation. Since there is a good correlation, NOx and smoke can be predicted for any intermediate load conditions. This helps the manufacturers to meet the emission regulations for Euro norms.

scholarly journals Effects of Ethanol–Diesel on the Combustion and Emissions from a Diesel Engine at a Low Idle Speed

2020 ◽  
Vol 10 (12) ◽  
pp. 4153 ◽  
Author(s):  
Ho Young Kim ◽  
Jun Cong Ge ◽  
Nag Jung Choi
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Direct Injection ◽  
Maximum Heat ◽  
Idle Speed ◽  
Indicated Mean Effective Pressure ◽  
Combustion Duration ◽  
Mean Size ◽  
Maximum Heat Release ◽  
Blended Fuels

In this study, detailed experiments were conducted on the combustion and exhaust characteristics of ethanol–diesel blended fuels. The four-stroke four-cylinder common-rail direct injection diesel engine was used. The experiment was carried out at 750 rpm at a low speed idle, and a 40 Nm engine load was applied to simulate the operation of the accessories during the low idle operation of the actual vehicles. The test fuels were four types of ethanol-blended fuel. The ethanol blending ratios were 0% (DE_0) for pure diesel, and 3% (DE_3), 5% (DE_5) and 10% (DE_10) for 3%, 5% and 10% ethanol mixtures (by vol.%). Blending ethanol with diesel fuel increased the maximum combustion pressure by up to 4.1% compared with that of pure diesel fuel, and the maximum heat release rate increased by 13.5%. The brake specific fuel consumption (BSFC) increased, up to 5.9%, as the ethanol blending ratio increased, while the brake thermal efficiency (BTE) for diesel-ethanol blended fuels remained low, and was maintained at 23.8%. The coefficient of variation (COV) of the indicated mean effective pressure (IMEP) was consistently lower than 1% when ethanol was blended. The blending of ethanol increased the ignition delay from a 12.0 degree crank angle (°CA) at DE_0 to 13.7 °CA at DE_10, and the combustion duration was reduced from 21.5 °CA at DE_0 to 20.8 °CA at DE_10. When ethanol blending was applied, nitrogen oxides (NOx) reduced to 93.5% of the level of pure diesel fuel, the soot opacity decreased from 5.3% to 3% at DE_0, and carbon monoxide increased (CO) by 27.4% at DE_10 compared with DE_0. The presence of hydrocarbon (HC) decreased to 50% of the level of pure diesel fuel, but increased with a further increase in the ethanol blending ratio. The mean size of the soot particulates was reduced by 26.7%, from 33.9 nm for pure diesel fuel, DE_0, to 24.8 nm for DE_10.

Effect of Injection Timing on Combustion Characteristics of a DI Diesel Engine Fuelled with Pistacia chinensis Bunge Seed Biodiesel

2012 ◽  
Vol 614-615 ◽  
pp. 337-342
Author(s):  
Li Luo ◽  
Bin Xu ◽  
Zhi Hao Ma ◽  
Jian Wu ◽  
Ming Li
Keyword(s):  
Combustion Temperature ◽  
Fuel Injection ◽  
Direct Injection ◽  
Combustion Characteristics ◽  
Injection Timing ◽  
Brake Specific Fuel Consumption ◽  
Cylinder Pressure ◽  
Combustion Duration ◽  
Di Diesel Engine ◽  
Maximum Combustion Temperature

In this study, the effect of injection timing on combustion characteristics of a direct injection, electronically controlled, high pressure, common rail, turbocharged and intercooled engine fuelled with different pistacia chinensis bunge seed biodiesel/diesel blends has been experimentally investigated. The results indicated that brake specific fuel consumption reduces with the increasing of fuel injection advance angle and enhances with the increasing of biodiesel content in the blends. The peak of cylinder pressure and maximum combustion temperature increase evidently with the increment of fuel injection advance angle. However, the combustion of biodiesel blends starts earlier than diesel at the same fuel injection advance angle. At both conditions, the combustion duration and the peak of heat release rate are insensitive to the changing of injection timing.

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