scholarly journals Oxygen-Enriched Diesel Engine Performance: A Comparison of Analytical and Experimental Results

1991 ◽  
Vol 113 (3) ◽  
pp. 365-369 ◽  
Author(s):  
R. R. Sekar ◽  
W. W. Marr ◽  
D. N. Assanis ◽  
R. L. Cole ◽  
T. J. Marciniak ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Experimental Studies ◽  
Engine Performance ◽  
Oxygen Enrichment ◽  
Published Data ◽  
Particulate Emissions ◽  
Lower Grade ◽  
Nox Emissions ◽  
Release Rates

Use of oxygen-enriched combustion air in diesel engines can lead to significant improvements in power density, as well as reductions in particulate emissions, but at the expense of higher NOx emissions. Oxygen enrichment would also lead to lower ignition delays and the opportunity to burn lower grade fuels. Analytical and experimental studies are being conducted in parallel to establish the optimal combination of oxygen level and diesel fuel properties. In this paper, cylinder pressure data acquired on a single-cylinder engine are used to generate heat release rates for operation under various oxygen contents. These derived heat release rates are in turn used to improve the combustion correlation—and thus the prediction capability—of the simulation code. It is shown that simulated and measured cylinder pressures and other performance parameters are in good agreement. The improved simulation can provide sufficiently accurate predictions of trends and magnitudes to be useful in parametric studies assessing the effects of oxygen enrichment and water injection on diesel engine performance. Measured ignition delays, NOx emissions, and particulate emissions are also compared with previously published data. The measured ignition delays are slightly lower than previously reported. Particulate emissions measured in this series of tests are significantly lower than previously reported.

Two-Stroke Marine Diesel Engine Variable Injection Timing System Performance Evaluation and Optimum Setting for Minimum Fuel Consumption at Acceptable NOx Levels

2014 ◽  
Author(s):  
Dimitrios T. Hountalas ◽  
Spiridon Raptotasios ◽  
Antonis Antonopoulos ◽  
Stavros Daniolos ◽  
Iosif Dolaptzis ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Injection Timing ◽  
Nox Emissions ◽  
Pressure Measurements ◽  
Cylinder Pressure ◽  
Start Of Injection

Currently the most promising solution for marine propulsion is the two-stroke low-speed diesel engine. Start of Injection (SOI) is of significant importance for these engines due to its effect on firing pressure and specific fuel consumption. Therefore these engines are usually equipped with Variable Injection Timing (VIT) systems for variation of SOI with load. Proper operation of these systems is essential for both safe engine operation and performance since they are also used to control peak firing pressure. However, it is rather difficult to evaluate the operation of VIT system and determine the required rack settings for a specific SOI angle without using experimental techniques, which are extremely expensive and time consuming. For this reason in the present work it is examined the use of on-board monitoring and diagnosis techniques to overcome this difficulty. The application is conducted on a commercial vessel equipped with a two-stroke engine from which cylinder pressure measurements were acquired. From the processing of measurements acquired at various operating conditions it is determined the relation between VIT rack position and start of injection angle. This is used to evaluate the VIT system condition and determine the required settings to achieve the desired SOI angle. After VIT system tuning, new measurements were acquired from the processing of which results were derived for various operating parameters, i.e. brake power, specific fuel consumption, heat release rate, start of combustion etc. From the comparative evaluation of results before and after VIT adjustment it is revealed an improvement of specific fuel consumption while firing pressure remains within limits. It is thus revealed that the proposed method has the potential to overcome the disadvantages of purely experimental trial and error methods and that its use can result to fuel saving with minimum effort and time. To evaluate the corresponding effect on NOx emissions, as required by Marpol Annex-VI regulation a theoretical investigation is conducted using a multi-zone combustion model. Shop-test and NOx-file data are used to evaluate its ability to predict engine performance and NOx emissions before conducting the investigation. Moreover, the results derived from the on-board cylinder pressure measurements, after VIT system tuning, are used to evaluate the model’s ability to predict the effect of SOI variation on engine performance. Then the simulation model is applied to estimate the impact of SOI advance on NOx emissions. As revealed NOx emissions remain within limits despite the SOI variation (increase).

Diesel engine performance at the intake of the hydrogen&air mixture

2021 ◽  
pp. 119-126
Author(s):  
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Internal Combustion Engines ◽  
Fuel Efficiency ◽  
Experimental Studies ◽  
Motor Fuel ◽  
Engine Performance ◽  
Calorific Value ◽  
Hydrocarbon Emissions ◽  
The Difference

The prospects of using hydrogen as a motor fuel are noted. The problems that arise when converting a diesel engine to run on hydrogen are considered. The features of the organization of the working process of enginesrunning on hydrogen are analyzed. A method of supplying a hydrogenair mixture to a diesel engine is investigated. To supply hydrogen to the engine cylinders, it is proposed to use the Leader4M installation developed by TechnoHill Club LLC (Moscow). Experimental studies of a stationary diesel engine of the D245.12 S type with the supply of hydrogen at the inlet obtained at this installation are carried out. At the maximum power mode, the supply of hydrogen from this installation to the inlet of the diesel engine under study was 0.9 % by weight (taking into account the difference in the calorific value of oil diesel fuel and hydrogen). Such a supply of hydrogen in the specified mode made it possible to increase the fuel efficiency of the diesel engine and reduce the smoke content of exhaust gases, carbon monoxide and unburned hydrocarbon emissions. Keywords internal combustion engines; diesel engine; diesel fuel; hydrogen; hydrogenair mixture; fuel efficiency; exhaust gas toxicity indicators

Evaluation of Biodiesel Blends in a Single-Cylinder Medium-Speed Diesel Engine

2005 ◽  
Author(s):  
Fan Su ◽  
Malcolm Payne ◽  
Manuel Vazquez ◽  
Peter Eggleton ◽  
Alex Vincent
Keyword(s):  
Diesel Engine ◽  
Fuel Economy ◽  
Engine Performance ◽  
Injection Pressure ◽  
Frying Oil ◽  
Nox Emissions ◽  
Biodiesel Blends ◽  
Single Cylinder ◽  
Additional Information ◽  
Medium Speed

Biodiesel blends were prepared by mixing low sulphur #2 diesel and biodiesel of two origins (canola and frying oil) at two different concentrations (5% and 20%). They were tested in a single-cylinder four-stroke medium-speed diesel engine under three engine modes representing idle, about 50% power and full load conditions. Engine performance and emissions data obtained with the blends were compared to that of engine running with the #2 diesel. Results indicated that the 5% blends could maintain engine power and fuel economy. Frying oil based B5 provided more significant reductions on CO, THC and PM emissions and increments on NOx emissions as compared with that of the canola B5 fuel. The 20% blends reduce engine CO, PM and smoke emissions, but increase NOx emissions by up to approximately 8%. Engine cylinder pressure and injection pressure data was also collected to provide additional information for evaluation of fuel economy and emissions benefits of using the blends.

Steady State Diesel Engine Performance and NOx Emissions with Selected Biofuels

2005 ◽  
Author(s):  
Alan C. Hansen ◽  
Michael R. Gratton ◽  
Wenqiao Yuan
Keyword(s):  
Steady State ◽  
Diesel Engine ◽  
Engine Performance ◽  
Nox Emissions

Combustion of Coal-Water Slurry in a Two-Cycle Diesel Engine: Effects of Fuel Amount and Timing

1990 ◽  
Vol 112 (3) ◽  
pp. 376-383 ◽  
Author(s):  
T. Uzkan ◽  
C. E. Horton
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Cylinder Pressure ◽  
Release Rates ◽  
Energy Of Combustion ◽  
Water Slurry ◽  
Coal Particles ◽  
Coal Water Slurry ◽  
Temperature Heat ◽  
Pilot Fuel

Coal-water slurry having micronized coal particles with approximately 50 percent coal loading is successfully ignited and combusted in one cylinder of a two-cylinder 645 EMD engine by using diesel fuel pilot ignition aid. The effects of three different parameters, namely, (a) pilot timing, (b) pilot amount, and (c) CWS fuel amount, are investigated in detail. The physical trends of combustion under single parametric variations are presented in terms of the cylinder pressure, temperature, heat release rates, and cumulative heat release curves. CWS combustion with less than 5 percent of the energy of combustion coming from pilot fuel is achieved.

Effects of Different Biodiesel Blends on Heat Release and Its Related Parameters

2006 ◽  
Author(s):  
Girish Parvate-Patil ◽  
Manuel Vasquez ◽  
Malcolm Payne
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Fuel Injection ◽  
Load Condition ◽  
Engine Performance ◽  
Injection Pressure ◽  
Single Cylinder ◽  
Medium Speed ◽  
Performance And Emissions ◽  
Fuel Injection Pressure

This paper emphasizes on the effects of different biodiesels and diesel on; heat release, ignition delay, endothermic and exothermic reactions, NOx, fuel injection pressure due to the fuel’s modulus of elasticity and cylinder pressure. Two 100% biodiesel and its blends of 20% with of low sulfur #2 diesel, and #2 diesel are tested on a single cylinder diesel engine under full load condition. Engine performance and emissions data is obtained for 100% and 20% biodiesels blends and #2 diesel. Testes were conducted at Engine Systems Development Centre, Inc. (ESDC) to evaluate the effects of biodiesel and its blends on the performance and emissions of a single-cylinder medium-speed diesel engine. The main objective of this work was to gain initial information and experience about biodiesel for railway application based on which biodiesel and its blends could be recommended for further investigation on actual locomotives.

scholarly journals A Comparative Study of Almond Biodiesel-Diesel Blends for Diesel Engine in Terms of Performance and Emissions

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Nidal H. Abu-Hamdeh ◽  
Khaled A. Alnefaie
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Engine Performance ◽  
Particulate Emissions ◽  
Exhaust Gas ◽  
Oxides Of Nitrogen ◽  
Performance Parameters ◽  
Gas Temperature ◽  
Performance And Emissions ◽  
Unburned Fuel

This paper investigates the opportunity of using almond oil as a renewable and alternative fuel source. Different fuel blends containing 10, 30, and 50% almond biodiesel (B10, B30, and B50) with diesel fuel (B0) were prepared and the influence of these blends on emissions and some performance parameters under various load conditions were inspected using a diesel engine. Measured engine performance parameters have generally shown a slight increase in exhaust gas temperature and in brake specific fuel consumption and a slight decrease in brake thermal efficiency. Gases investigated were carbon monoxide (CO) and oxides of nitrogen (NOx). Furthermore, the concentration of the total particulate and the unburned fuel emissions in the exhaust gas were tested. A blend of almond biodiesel with diesel fuel gradually reduced the engine CO and total particulate emissions compared to diesel fuel alone. This reduction increased with more almond biodiesel blended into the fuel. Finally, a slight increase in engineNOxusing blends of almond biodiesel was measured.

Optical Investigation of the Effects of Ethanol/Gasoline Blends on Spark-Assisted HCCI

2013 ◽  
Author(s):  
Mohammad Fatouraie ◽  
Margaret S. Wooldridge
Keyword(s):  
Heat Release ◽  
High Speed ◽  
Engine Performance ◽  
Optical Investigation ◽  
Release Rates ◽  
High Speed Imaging ◽  
Engine Operation ◽  
Spark Timing ◽  
Combustion Properties ◽  
Ethanol Blends

Spark assist (SA) has been demonstrated to extend the operating limits of homogeneous charge compression ignition (HCCI) modes of engine operation. This experimental investigation focuses on the effects of 100% indolene and 70% indolene/30% ethanol blends on the ignition and combustion properties during SA HCCI operation. The spark assist effects are compared to baseline HCCI operation for each blend by varying spark timing at different fuel/air equivalence ratios ranging from ϕ = 0.4–0.5. High speed imaging is used to understand connections between spark initiated flame propagation and heat release rates. Ethanol generally improves engine performance with higher IMEPn and higher stability compared to 100% indolene. SA advances phasing within a range of ∼5 CAD at lower engine speeds (700 RPM) and ∼11 CAD at higher engine speeds (1200 RPM). SA does not affect heat release rates until immediately (within ∼5 CAD) prior to autoignition. Unlike previous SA HCCI studies of indolene fuel in the same engine, flames were not observed for all SA conditions.

Impact of Intake Induced Swirl on Combustion and Emissions on a Single Cylinder Diesel Engine

2016 ◽  
Author(s):  
Eduardo Barrientos ◽  
Ivan Bortel ◽  
Michal Takats ◽  
Jiri Vavra
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Operating Conditions ◽  
Common Rail ◽  
Injection System ◽  
Nox Emissions ◽  
Cylinder Pressure ◽  
Swirl Ratio ◽  
Single Cylinder ◽  
Optimal Values

Engine induced swirl improves mixing of fuel and air and at optimal values accelerates burn, improves the combustion stability and can decrease particulate matter (PM). However, swirl increases convective heat loss and cylinder charge loss and could increase nitrogen oxides (NOx) emissions. High intensity of swirl could impede flame development and increases emissions of total hydrocarbons (THC) and carbon monoxide (CO). Therefore, careful and smart selection of optimal swirl values is paramount in order to obtain beneficial impact on combustion and emissions performance. This study is conducted on a 0.5L single cylinder research engine with common rail (CR) diesel injection system, with parameters corresponding to modern engines of passenger cars. The engine has three separate ports in the cylinder head. The change of swirl ratio is defined by closing appropriate ports. There are three levels of swirl ratio under study — 1.7, 2.9 and 4.5, corresponding to low, medium and high swirl levels respectively. This study highlights the influence of intake induced swirl on combustion parameters and emissions. Assessed combustion parameters are, among others, heat release rate, cylinder pressure rise and indicated mean effective pressure. Assessed emissions are standard gaseous emissions and smoke, with emphasis on PM emissions. An engine speed of 1500 rpm was selected, which well represents common driving conditions of this engine size. Various common rail pressures are used at ambient inlet manifold pressure (without boost pressure) and at 1 bar boosted pressure mode. It is found that when the swirl level is increased, the faster heat release during the premixed combustion and during early diffusion-controlled combustion causes a quick increase in both in-cylinder pressure and temperature, thus promoting the formation of NOx. However, since swirl enhances mixing and potentially produces a leaning effect, PM formation is reduced in general. However, maximum peak temperature is lower for high swirl ratio and boosted modes due to the increase of heat transfer into cylinder walls. Furthermore, it is necessary to find optimal values of common rail pressures and swirl ratio. Too much mixing allows increase on PM, THC and CO emissions without decrease on NOx emissions in general. Common rail injection system provides enough energy to achieve good mixing during all the injection time in the cases of supercharged modes and high common rail pressure modes. Positive influence of swirl ratio is found at lower boost pressures, lower revolution levels and at lower engine loads. The results obtained here help providing a better understanding on the swirl effects on diesel engine combustion and exhaust emissions over a range of engine operating conditions, with the ultimate goal of finding optimal values of swirl operation.

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