Real-gas properties of n-alkanes, O2, N2, H2O, CO, CO2, and H2 for diesel engine operation conditions

2009 ◽  
Vol 3 (8) ◽  
pp. 1191-1252 ◽  
Author(s):  
S. M. Frolov ◽  
N. M. Kuznetsov ◽  
C. Krueger
Author(s):  
Junfeng Yang ◽  
Monica Johansson ◽  
Valeri Golovitchev

A comparative study on engine performance and emissions (NOx, soot) formation has been carried out for the Volvo D12C diesel engine fueled by Rapeseed Methyl Ester, RME and conventional diesel oil. The combustion models, used in this paper, are the modifications of those described in [1–2]. After the compilation of liquid properties of RME specified as methyl oleate, C19H36O2, making up 60% of RME. The oxidation mechanism has been compiled based on methyl butanoate ester, mb, C5H10O2 oxidation model [3] supplemented by the sub-mechanisms for two proposed fuel constituent components, methyl decanoate, md, C11H22O2, n-heptane, C7H16, and soot and NOx formations reduced and “tuned” by using the sensitivity analysis. A special global reaction was introduced to “crack” the main fuel into constituent components, md, mb and propyne, C3H4, to reproduce accurately the proposed RME chemical formula. The sub-mechanisms were collected in the general one consisting of 99 species participating in 411 reactions. The combustion mechanism was validated using shock-tube ignition-delay data at diesel engine conditions and flame propagation speeds at atmospheric conditions. The engine simulations were carried out for Volvo D12C engine fueled both RME and conventional diesel oil. The numerical results illustrate that in the case of RME, nearly 100% combustion efficiency was predicted when the cumulative heat release, was compared with the RME LHV, 37.2 kJ/g.. To minimize NOx emissions, the effects of 20–30% EGR levels depending on the engine loads and different injection strategies were analyses. To confirm the optimal engine operation conditions, a special technique based on the time-transient parametric φ-T maps [4] has been used.


2009 ◽  
Vol 131 (1) ◽  
Author(s):  
Talal F. Yusaf

Performance and emission testing for a single cylinder four-stroke diesel engine have been experimentally performed to determine the optimum operation conditions for this engine when it is used as a hybrid power unit. The studied operation parameters included brake specific fuel consumption (BSFC), exhaust emission (NOx, CO, CO2, and O2), and engine life. The results indicate that the lowest BSFC of the engine was found when the engine runs around 1 kW charging load at speed ranged between 1900 rpm and 2700 rpm. As the speed of the engine is maintained constant, the minimum level of BSFC is below 300 g/kW h at around 1900 rpm. The best engine operation conditions, for low emission, are found at engine speed around 2500 rpm. It was found that the oxides of nitrogen remain within the acceptable level (below 180 ppm) for such a diesel engine. The battery charge has been conducted at constant speeds, where the lubricant oil temperature was constant and always below maximum temperature; this is a good indication for longer engine life.


Author(s):  
Petar Kazakov ◽  
Atanas Iliev ◽  
Emil Marinov

Over the decades, more attention has been paid to emissions from the means of transport and the use of different fuels and combustion fuels for the operation of internal combustion engines than on fuel consumption. This, in turn, enables research into products that are said to reduce fuel consumption. The report summarizes four studies of fuel-related innovation products. The studies covered by this report are conducted with diesel fuel and usually contain diesel fuel and three additives for it. Manufacturers of additives are based on already existing studies showing a 10-30% reduction in fuel consumption. Comparative experimental studies related to the use of commercially available diesel fuel with and without the use of additives have been performed in laboratory conditions. The studies were carried out on a stationary diesel engine СМД-17КН equipped with brake КИ1368В. Repeated results were recorded, but they did not confirm the significant positive effect of additives on specific fuel consumption. In some cases, the factors affecting errors in this type of research on the effectiveness of fuel additives for commercial purposes are considered. The reasons for the positive effects of such use of additives in certain engine operating modes are also clarified.


Author(s):  
Ming Zheng ◽  
David K. Irick ◽  
Jeffrey Hodgson

For diesel engines (CIDI) the excessive use of exhaust gas recirculation (EGR) can reduce in-cylinder oxides of nitrogen (NOx) generation dramatically, but engine operation can also approach zones with high instabilities, usually accompanied with high cycle-to-cycle variations and deteriorated emissions of total hydrocarbon (THC), carbon monoxide (CO), and soot. A new approach has been proposed and tested to eliminate the influences of recycled combustibles on such instabilities, by applying an oxidation catalyst in the high-pressure EGR loop of a turbocharged diesel engine. The testing was directed to identifying the thresholds of stable operation at high rates of EGR without causing cycle-to-cycle variations associated with untreated recycled combustibles. The elimination of recycled combustibles using the oxidation catalyst showed significant influences on stabilizing the cyclic variations, so that the EGR applicable limits are effectively extended. The attainability of low NOx emissions with the catalytically oxidized EGR is also evaluated.


2021 ◽  
pp. 28-32
Author(s):  
VALERIY L. CHUMAKOV ◽  

The paper shows some ways to improve the environmental characteristics of a diesel engine using gaseous hydrocarbon fuel and operating the engine in a gas-diesel cycle mode. Some possibilities to reduce toxic components of exhaust gases in a gas-diesel engine operating on liquefi ed propane-butane mixtures have been studied. Experiments carried out in a wide range of load from 10 to 100% and speed from 1400 to 2000 rpm showed that the gas-diesel engine provides a suffi ciently high level of diesel fuel replacement with gas hydrocarbon fuel. The authors indicate some eff ective ways to reduce the toxicity of exhaust gases. The engine power should be adjusted by the simultaneous supply of fuel, gas and throttling the air charge in the intake manifold. This method enriches the fi rst combusting portions to reduce nitrogen oxides and maintains the depletion of the main charge within the fl ammability limits of the gas-air charge to reduce carbon monoxide and hydrocarbons. The authors found that when the engine operates in a gas-diesel cycle mode, the power change provides a decrease in nitrogen oxide emissions of gas-diesel fuel only due to gas supply in almost the entire load range as compared to the pure diesel. At high loads (more than 80%) stable engine operation is ensured up to 90% of diesel fuel replaced by gas. Even at 10% of diesel fuel used the concentration of nitrogen oxides decreases by at least 15…20% as compared with a diesel engine in the entire load range. However, there is an increased emission of hydrocarbons and carbon monoxide in the exhaust gases. Further experimental studies have shown that optimization of the gas diesel regulation can reduce the mass emission of nitrogen oxides contained in exhaust gases in 2…3 times and greatly reduce the emission of incomplete combustion products – carbon monoxide and hydrocarbons.


2012 ◽  
Vol 155-156 ◽  
pp. 12-17 ◽  
Author(s):  
Lian Xu Wang ◽  
Da Wei Qu ◽  
Chang Qing Song ◽  
Ye Tian

To research the performance optimization of high speed car diesel engine,firstly according to the characteristic of car diesel engine with Variable Nozzle Turbocharger (VNT), one-dimensional cycle model of the engine was established by using simulation software BOOST and validated by experimental data in this paper. The turbine blades’ opening corresponding to different speed was determined. Therefore the problem that the VNT surges at low engine speed and the inlet air flow is insufficient at high speed was solved. Based on the above model, this paper improved the efficiency of the engine by optimizing the compression ratio and the distribution phase of camshaft and then used the experimental data to check the simulation results. Meanwhile the fuel consumption and the possibility of the engine operation roughness decreased.


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