Evaluating the Influence of Exhaust Back Pressure on Performance and Exhaust Emissions Characteristics of a Multicylinder, Turbocharged, and Aftercooled Diesel Engine

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Mayank Mittal ◽  
Ron Donahue ◽  
Peter Winnie

An experimental study was conducted to quantify the effects of exhaust back pressure (EBP) on performance and exhaust emissions characteristics of a diesel engine for generator application. The electromechanical system was composed of a commercially available six-cylinder, turbocharged, and aftercooled diesel engine, coupled with a generator rated at 500 kilowatt electrical (kWe) at full load. Experiments were conducted at different operating conditions for high and low EBPs. Exhaust emissions of nitrogen oxides (NOx), soot, particulate matter (PM), carbon monoxide (CO), and total hydrocarbons (HC) were measured. In addition, thermocouples and pressure sensors were provided at various locations to evaluate the engine performance. Results showed that the brake specific fuel consumption (BSFC) was increased at light loads for high EBP, but no significant difference was observed in BSFC at high loads. It was found that NOx emission was reduced at all operating loads, but soot and PM were increased with the increase in EBP. HC emission was relatively insensitive with increment of EBP.

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Bjorn S. Santos ◽  
Sergio C. Capareda ◽  
Jewel A. Capunitan

Biodiesel from sunflower oil offers a potential as an alternative to petroleum-based diesel fuel and must be evaluated in terms of the resulting engine performance and exhaust emissions. Two diesel engines rated at 14.2 kW (small) and 60 kW (large) were operated on pure sunflower methyl ester (SFME) and its blends with a reference diesel (REFDIESEL). Results showed that less power and torque were delivered by both the small and large engines when ran on pure SFME than on REFDIESEL, while brake-specific fuel consumption (BSFC) was found to be higher in pure SFME. Blends of SFME with REFDIESEL (B5 and B20) showed negligible power loss and similar BSFC with the REFDIESEL. Higher concentrations of nitrogen oxides (), carbon dioxide (CO2), and total hydrocarbons (THC) in the exhaust emissions were observed for both pure SFME and SFME-REFDIESEL fuel blends. Comparison with soybean methyl ester indicates similar engine performance. Thus, blends of SFME with diesel may be used as a supplemental fuel for steady-state nonroad diesel engines to take advantage of the lubricity of biodiesel as well as contributing to the goal of lowering the dependence to petroleum diesel.


2014 ◽  
Vol 630 ◽  
pp. 334-340 ◽  
Author(s):  
Andrzej Bąkowski ◽  
Jerzy Jaroszewicz ◽  
Leszek Radziszewski

An analytical and experimental model was proposed to determine sac volume pressure changes and fuel doses injected into the diesel engine cylinders. The model takes into account friction forces and identifies the mechanical properties of the injector. The engine performance results were analysed statistically. The results of the Lilliefors, Pearson, Shapiro-Wilk and Jarque-Bera tests provided evidence that, under certain engine operating conditions, the null hypothesis about the compatibility of the measurement data with the normal distribution can be rejected. The measurement uncertainty for the injector needle lift was estimated. The engine was powered with diesel or biofuel. The difference between the measured and the predicted fuel doses amounted to approximately 3%.


2021 ◽  
Vol 18 (22) ◽  
pp. 451
Author(s):  
Ekkachai Sutheerasak ◽  
Charoen Chinwanitcharoen ◽  
Sathaporn Chuepeng

Biofuels are an alternative fuel currently being developed to reduce the diesel-engine environmental impact. The release of carbon dioxide (CO2), nitric oxide (NO) and black smoke (BS) becomes an issue derived from diesel engines even in lean-mixture combustion causing an adverse effect to human health. The main aim of the research study is to present the use of biofuels, a mixture of diesel and 10 % palm oil ethyl ester (PEE10) and PEE10 blended with bioethanol from 5 to 20 %, compared with conventional diesel fuel. The biofuels were run on a high-speed direct injection diesel engine at a constant speed of 3,000 rpm under various loads. The use of PEE10 resulted in brake thermal efficiency (BTE) reduction by 2 % and brake specific fuel consumption (BSFC) incrementation by 8 %, but the exhaust emissions were lower than diesel, except for CO2 and NO. However, PEE10 engine performance was better and exhaust gas emissions were lower for both pollutants than diesel mixed with 10 % bioethanol. The investigation of PEE10 with increasing bioethanol revealed that the use of PEE10 blended with 5 % bioethanol (PEE10E5) can improve engine performance, while the BTE and BSFC were close to that of diesel, and exhaust emissions, especially CO2, NO and BS reduced. Moreover, BTE from PEE10E5 fueling increased by 2 % but BSFC was subtle increased, compared to PEE10. On the other hand, the increasing bioethanol from 10 to 20 % in PEE10 led to the more reduction in engine performance, but the engine pollutants were also continuously decreased. Specifically, the blend of PEE10 and 20 % bioethanol indicates that CO2, NO and BS were reduced by 10, 15 and 33 %, respectively, compared to diesel fuel. HIGHLIGHTS A mixture of diesel and 10 % palm oil ethyl ester (PEE10) has less exhaust emissions than diesel blended with 10 % palm oil methyl ester (PME10) PEE10 blended with 5 % bioethanol can improve engine performance, while the brake thermal efficiency and brake specific fuel consumption are close to that of diesel and PME10 The increasing bioethanol from 10 to 20 % in PEE10 leads to the more reduction in engine performance, but the engine pollutants, especially carbon dioxide, nitric oxide and black smoke, are also continuously decreased GRAPHICAL ABSTRACT


2013 ◽  
Vol 465-466 ◽  
pp. 221-225 ◽  
Author(s):  
Mohd Hafizil Mat Yasin ◽  
Rizalman Mamat ◽  
Abdul Mutalib Leman ◽  
Amir Khalid ◽  
Noreffendy Tamaldin

Biodiesel is an alternative, decomposable and biological-processed fuel that has similar characteristics with mineral diesel which can be used directly into diesel engines. However, biodiesel has its drawbacks which are more density and viscosity compared to mineral diesel. Alcohol additives implementation such as ethanol could reduce significantly the density and viscosity of the biodiesel. In this study, biodiesel (20%)-ethanol (5%)-diesel (75%), biodiesel (20%)-methanol (10%)-diesel (70%), biodiesel (20%)-ethanol (15%)-diesel (65%), biodiesel (20%)-ethanol (20%)-diesel (60%) and standard mineral diesel as a baseline fuel are tested in a Mitsubishi 4D68 diesel engine. Those test fuels are investigated under the same operating conditions at three different engine loads; 20%, 40% and 60% at a constant engine speed of 2500 rpm to determine the engine performance, combustion and emission of the diesel engine. Overall, biodiesel-ethanol-diesel blends show higher brake specific fuel consumption than mineral diesel especially at higher ethanol concentration. As ethanol proportions in blends increase, CO emissions increase, while NO emissions are reduced. Also, biodiesel-ethanol blend with 5% ethanol is more effective than other biodiesel-ethanol blends for reducing CO emissions and improve the combustion.


Author(s):  
Dimitrios T. Hountalas ◽  
Spiridon Raptotasios ◽  
Antonis Antonopoulos ◽  
Stavros Daniolos ◽  
Iosif Dolaptzis ◽  
...  

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).


Author(s):  
Teja Gonguntla ◽  
Robert Raine ◽  
Leigh Ramsey ◽  
Thomas Houlihan

The objective of this project was to develop both engine performance and emission profiles for two test fuels — a 6% water-in-diesel oil emulsion (DOE-6) fuel and a neat diesel (D100) fuel. The testing was performed on a single cylinder, direct-injection, water-cooled diesel engine coupled to an eddy current dynamometer. Output parameters of the engine were used to calculate Brake Specific Fuel Consumption (BSFC) and Engine Efficiency (η) for each test fuel. DOE-6 fuels generated a 24% reduction in NOX and a 42% reduction in Carbon Monoxide emissions over the tested operating conditions. DOE-6 fuels presented higher ignition delays — between 1°-4°, yielded 1%–12% lower peak cylinder pressures and produced up to 5.5% lower exhaust temperatures. Brake Specific Fuel consumption increased by 6.6% for the DOE-6 fuels as compared to the D100 fuels. This project is the first research done by a New Zealand academic institution on water-in-diesel emulsion fuels.


Author(s):  
F. Daneshvar ◽  
N. Jahani ◽  
M. B. Shafii

In this experimental study, a four stroke diesel engine was conducted to investigate the effect of adding water-based ferrofluid to diesel fuel on engine performance. To our knowledge, Magnetic nanoparticles had not been used before. To this end, emulsified diesel fuels of 0, 0.4, and 0.8 water-based ferrofluid/Diesel ratios by volume were used as fuel. The ferrofluid used in this study was a handmade water-based ferrofluid prepared by the authors. The results show that adding water-based ferrofluid to diesel fuel has a perceptible effect on engine performance, increasing the brake thermal efficiency relatively up to 12%, and decreasing the brake specific fuel consumption relatively up to 11% as compared to diesel fuel. In addition, the results indicate that increasing ferrofluid concentration will magnify the results. Furthermore, it was found that magnetic nanoparticles can be collected at the engine exhaust using magnetic bar.


Transport ◽  
2014 ◽  
Vol 29 (4) ◽  
pp. 440-448 ◽  
Author(s):  
Tomas Mickevičius ◽  
Stasys Slavinskas ◽  
Slawomir Wierzbicki ◽  
Kamil Duda

This paper presents a comparative analysis of the diesel engine performance and emission characteristics, when operating on diesel fuel and various diesel-biodiesel (B10, B20, B40, B60) blends, at various loads and engine speeds. The experimental tests were performed on a four-stroke, four-cylinder, direct injection, naturally aspirated, 60 kW diesel engine D-243. The in-cylinder pressure data was analysed to determine the ignition delay, the Heat Release Rate (HRR), maximum in-cylinder pressure and maximum pressure gradients. The influence of diesel-biodiesel blends on the Brake Specific Fuel Consumption (bsfc) and exhaust emissions was also investigated. The bench test results showed that when the engine running on blends B60 at full engine load and rated speed, the autoignition delay was 13.5% longer, in comparison with mineral diesel. Maximum cylinder pressure decreased about 1–2% when the amount of Rapeseed Methyl Ester (RME) expanded in the diesel fuel when operating at full load and 1400 min–1 speed. At rated mode, the minimum bsfc increased, when operating on biofuel blends compared to mineral diesel. The maximum brake thermal efficiency sustained at the levels from 0.3% to 6.5% lower in comparison with mineral diesel operating at full (100%) load. When the engine was running at maximum torque mode using diesel – RME fuel blends B10, B20, B40 and B60 the total emissions of nitrogen oxides decreased. At full and moderate load, the emission of carbon monoxide significantly raised as the amount of RME in fuel increased.


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