Steady State Diesel Engine Performance and NOx Emissions with Selected Biofuels

2005 ◽  
Author(s):  
Alan C. Hansen ◽  
Michael R. Gratton ◽  
Wenqiao Yuan
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):  
Fan Su ◽  
Malcolm Payne ◽  
Manuel Vazquez ◽  
Peter Eggleton ◽  
Alex Vincent

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.


1991 ◽  
Vol 113 (3) ◽  
pp. 365-369 ◽  
Author(s):  
R. R. Sekar ◽  
W. W. Marr ◽  
D. N. Assanis ◽  
R. L. Cole ◽  
T. J. Marciniak ◽  
...  

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.


2019 ◽  
Vol 42 ◽  
pp. e43882
Author(s):  
Omar Seye ◽  
Rubem Cesar Rodrigues Souza ◽  
Ramon Eduardo Pereira Silva ◽  
Robson Leal da Silva

This paper evaluates internal combustion engine performance parameters (Specific Fuel Consumption and engine torque) and pollutant emissions (O2, CO, and NOX), and also, provide an assessment of economic viability for operation in Amazonas state. Power supply to the communities in the Amazon region has as characteristics high costs for energy generation and low fare. Extractive activities include plenty of oily plant species, with potential use as biofuel for ICE (Diesel cycle) to obtain power generation together with pollutant emission reduction in comparison to fossil fuel. Experimental tests were carried out with five fuel blends (crude palm oil) and diesel, at constant angular speed (2,500 RPM – stationary regime), and four nominal engine loads (0%, 50%, 75%, and 100%) in a test bench dynamometer for an engine-driven generator for electrical-power, 4-Stroke internal combustion engine, Diesel cycle. Main conclusions are: a) SFC and torque are at the same order of magnitude for PO-00 (diesel) and PO-xx at BHP50/75/100%; b) O2 emissions show consistent decreasing behavior as BHP increases, compatible to a rich air-fuel ratio (λ > 1) and, at the same BHP condition, O2 (%) is slightly lower for higher PO-xx content; c) The CO emissions for PO-00 consistently decrease while the BHP increases, as for PO-xx those values present a non-linear behavior; at BHP75%-100_loads, CO emissions are higher for PO-20 and PO-25 in comparison to PO-00; d) The overall trend for NOX emissions is to increase, the higher the BHP; In general, NOx emissions are lower for PO-xx in comparison to PO-00, except for PO-10 which presents slightly higher values than PO-00 for all BHP range; e) Assessment on-trend costs indicates that using palm oil blends for Diesel engine-driven generators in the Amazon region is economically feasible, with an appropriate recommendation for a rated power higher than 800 kW.


2018 ◽  
Vol 225 ◽  
pp. 01013 ◽  
Author(s):  
Erdiwansyah ◽  
R. Mamat ◽  
M.S.M. Sani ◽  
Fitri Khoerunnisa ◽  
R.E Sardjono ◽  
...  

Biodiesel is an alternative fuel that is used in a diesel engine as a substitute for diesel fuel. However, using biodiesel without a modified engine can cause higher NOx emissions. Therefore, to reduce harmful emissions some strategy must be proposed or or a change in the injection is performed. In this study, injection schemes and engine performance injection time, emissions and firing characteristics of biodiesel mixing results in engines were investigated by using GT-POWER simulation. The simulations in this study were conducted on diesel engines to observe the accuracy in experimental results . The engines were tested at speeds of 1100 rpm, 1300 rpm, and 1500 rpm by using a biodiesel-diesel fuel mixture. The simulation results showed that NOx emissions were found to drop below 100 ppm when biodiesel fuel was used for all performed operations. Meanwhile CO emissions were also decreased by 10%-15% when biodiesel fuel was used, and the thermal efficiency level increased by 2% and 3.5% as compared to pure diesel. The ratio of NOx reduction rates of biodiesel and diesel was 11%-14% as compared to 9.5% with pure diesel. Based on the simulation result, it was shown that the accuracy level of simulation data with experiment was 97%. So this result can be the future testing standard and simulation by using GT-POWER could also be used especially for the automotive industry.


The paper investigated the effect of 1-hexanol fumigation in an engine performance using Moringa biodiesel blend. In this research, the biodiesel used is processed from Moringa Olifera seed. In this research tests were performed with the modification of a CI engine to carburet the hexanol into the intake manifold. Initially the experiment was conducted with diesel and Moringa biodiesel (MOME25), and then the test was conducted with various proportions of fumigated hexanol along with MOBD25. Results revealed that, the BTE was increased by 1.08% for MOBD25 with 10% n-hexanol fumigation compared with other diesel and other proportions of fumigations with MOBD25 blend. The NOx emission and smoke were diminished by 36% and 38% respectively for MOBD25 with 30% n-hexanol fumigation. It is concluded that 30% n-hexanol fumigation with MOBD25 blend drastically reduce the NOx emissions with the penalty of BTE.


2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Nikolaos-Alexandros Vrettakos

The operation during compressor surge of a medium speed marine diesel engine was examined on a test bed. The compressor of the engine's turbocharger was forced to operate beyond the surge line, by injecting compressed air at the engine intake manifold, downstream of the compressor during steady-state engine operation. While the compressor was surging, detailed measurements of turbocharger and engine performance parameters were conducted. The measurements included the use of constant temperature anemometry for the accurate measurement of air velocity fluctuations at the compressor inlet during the surge cycles. Measurements also covered engine performance parameters such as in-cylinder pressure and the impact of compressor surge on the composition of the exhaust gas emitted from the engine. The measurements describe in detail the response of a marine diesel engine to variations caused by compressor surge. The results show that both turbocharger and engine performance are affected by compressor surge and fast Fourier transform (FFT) analysis proved that they oscillate at the same main frequency. Also, prolonged steady-state operation of the engine with this form of compressor surge led to a non-negligible increase of NOx emissions.


2011 ◽  
Vol 130-134 ◽  
pp. 1744-1748
Author(s):  
Li Jun Ou ◽  
Chun Mei Wang ◽  
Ye Jian Qian ◽  
Wei Huang ◽  
Su Wei Zhu ◽  
...  

The present study investigates theoretically the effects of gasoline fumigation on single-cylinder diesel engine performance and emissions. The results indicate that a premixed charge can be obtained by early injection of gasoline because of the high volatility of gasoline. More homogenous mixture was obtained and the fuel burned faster and efficient. The smoke emission was reduced and engine output was increased. Coupling with EGR technique could reduce the NOx emissions simultaneously.


2020 ◽  
Vol 8 (10) ◽  
pp. 747
Author(s):  
Vladimir Pelić ◽  
Tomislav Mrakovčić ◽  
Vedran Medica-Viola ◽  
Marko Valčić

The energy efficiency and environmental friendliness of medium-speed marine diesel engines are to be improved through the application of various measures and technologies. Special attention will be paid to the reduction in NOx in order to comply with the conditions of the MARPOL Convention, Annex VI. The reduction in NOx emissions will be achieved by the application of primary and secondary measures. The primary measures relate to the process in the engine, while the secondary measures are based on the reduction in NOx emissions through the after-treatment of exhaust gases. Some primary measures such as exhaust gas recirculation, adding water to the fuel or injecting water into the cylinder give good results in reducing NOx emissions, but generally lead to an increase in fuel consumption. In contrast to the aforementioned methods, the use of an earlier inlet valve closure, referred to in the literature as the Miller process, not only reduces NOx emissions, but also increases the efficiency of the engine in conjunction with appropriate turbochargers. A previously developed numerical model to simulate diesel engine operation is used to analyse the effects of the Miller process on engine performance. Although the numerical model cannot completely replace experimental research, it is an effective tool for verifying the influence of various input parameters on engine performance. In this paper, the effect of an earlier closing of the intake valve and an increase in inlet manifold pressure on fuel consumption, pressure and temperature in the engine cylinder under steady-state conditions is analysed. The results obtained with the numerical model show the justification for using the Miller processes to reduce NOx emissions and fuel consumption.


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