scholarly journals A DIESEL ENGINE CONVERTED INTO OTTO CYCLE ENGINE: THE INFLUENCE OF THE SPARK ADVANCE ON ITS PERFORMANCE AND ON NOx EMISSIONS

2013 ◽  
Vol 12 (1) ◽  
pp. 37
Author(s):  
B. L. N. Oliveira ◽  
E. F. Jaguaribe ◽  
A. F. Bezerra ◽  
A. S. Rumão ◽  
B. L. C. Queiroga

This paper analyzes the performance of a diesel engine converted into an Otto cycle engine and its Nitrogen dioxide emissions in terms of the spark advance variation. The tests were conducted on a Perkins diesel engine 1104C - 44TAG turbocharged, whose compression ratio was reduced to 9.33:1. After conversion the engine started operating with liquefied petroleum gas (LPG) and running just with stoichiometric mixtures. The tests have been limited to 10 to 40 kW, always at 1800 rpm. During the experiments the ignition advance angle ranged from 5º up to 27º (BTDC), using the increment of 5°, whenever possible. Particularly at 40 kW, the range of the ignition advance was 15º to 20º. The results showed a significant influence of the spark advance angle on the fuel consumption, on the temperature and on the NOx emissions, as well as on the magnitude of the generated power.

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4442
Author(s):  
Branko Lalić ◽  
Andrijana Poljak ◽  
Gojmir Radica ◽  
Antonija Mišura

Knowing the process of generating exhaust emissions and the determination of influential parameters are important factors in improving two-stroke slow-speed marine engines, particularly for further reductions in fuel consumption and stringent regulations on the limitation of nitrogen oxide emissions. In this article, a model of a marine low-speed two-stroke diesel engine has been developed. Experimental and numerical analyses of the nitrogen monoxide formations were carried out. When measuring the concentration of nitrogen oxides in the exhaust emissions, the amount of nitrogen dioxide (NO2) is usually measured, because nitrogen monoxide is very unstable, and due to the large amount of oxygen in the exhaust gases, it is rapidly converted into nitrogen dioxide and its amount is included in the total emission of nitrogen oxides. In this paper, the most significant parameters for the formation of nitrogen monoxide have been determined. Model validation was performed based on measured combustion pressures, engine power, and concentrations of nitrogen oxides at 50% and 75% of maximum continuous engine load. The possibilities of fuel consumption optimization and reduction in nitrogen monoxide emissions by correcting the injection timing and changing the compression ratio were examined. An engine model was developed, based on measured combustion pressures and scavenging air flow, to be used on board by marine engineers for rapid analyses and determining changes in the concentration of nitrogen oxides in exhaust emissions. The amount of nitrogen oxide in exhaust emissions is influenced by the relevant features described in this paper: fuel injection timing and engine compression ratio. The presented methodology provides a basis for further research about the simultaneous impact of changing the injection timing and compression ratio, exhaust valve opening and closing times, as well as the impact of multiple fuel injection to reduce consumption and maintain exhaust emissions within the permissible limits.


2013 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
B. L. C. Queiroga ◽  
E. F. Jaguaribe ◽  
M. S. J. Gonçalves ◽  
B. L. N. Oliveira ◽  
A. S. Rumão

This paper discusses the conversion of a turbocharged diesel engine to operate with hydrous ethanol, using procedures developed in Innovation Lab of UFPB, IL. An diesel engine, brand Perkins, model 1104C-44TAG2, was converted to operate with hydrous ethanol at the time that it amended its compression ratio of 18:1 to 9.3:1, suitable for an Otto Cycle engine to non-occurrence of detonation fuel. Comparing experimental data generated for the converted engine tests (which ranged the ignition advance, stoichiometric air/fuel ratio and rotation at 1800 rpm) with those obtained in tests with the original engine, and converted, 45 kWe, a cost reduction of 34% with Ignition Advance of 20°. It was taken into account in this analysis, and data on fuel consumption, the cost of diesel, R$ 1.90/liter, and hydrous ethanol, R$ 0.70/liter. Regarding the gaseous emissions, depending on the load, it was found that the NOX ranged from 50 to 1050 ppm, CO, 1 to 3%, CO2, 12 to 15% and HC 150 to 450 ppm.


2021 ◽  
Vol 9 (2) ◽  
pp. 123
Author(s):  
Sergejus Lebedevas ◽  
Lukas Norkevičius ◽  
Peilin Zhou

Decarbonization of ship power plants and reduction of harmful emissions has become a priority in the technological development of maritime transport, including ships operating in seaports. Engines fueled by diesel without using secondary emission reduction technologies cannot meet MARPOL 73/78 Tier III regulations. The MEPC.203 (62) EEDI directive of the IMO also stipulates a standard for CO2 emissions. This study presents the results of research on ecological parameters when a CAT 3516C diesel engine is replaced by a dual-fuel (diesel-liquefied natural gas) powered Wartsila 9L20DF engine on an existing seaport tugboat. CO2, SO2 and NOx emission reductions were estimated using data from the actual engine load cycle, the fuel consumption of the KLASCO-3 tugboat, and engine-prototype experimental data. Emission analysis was performed to verify the efficiency of the dual-fuel engine in reducing CO2, SO2 and NOx emissions of seaport tugboats. The study found that replacing a diesel engine with a dual-fuel-powered engine led to a reduction in annual emissions of 10% for CO2, 91% for SO2, and 65% for NOx. Based on today’s fuel price market data an economic impact assessment was conducted based on the estimated annual fuel consumption of the existing KLASCO-3 seaport tugboat when a diesel-powered engine is replaced by a dual-fuel (diesel-natural gas)-powered engine. The study showed that a 33% fuel costs savings can be achieved each year. Based on the approved methodology, an ecological impact assessment was conducted for the entire fleet of tugboats operating in the Baltic Sea ports if the fuel type was changed from diesel to natural gas. The results of the assessment showed that replacing diesel fuel with natural gas achieved 78% environmental impact in terms of NOx emissions according to MARPOL 73/78 Tier III regulations. The research concludes that new-generation engines on the market powered by environmentally friendly fuels such as LNG can modernise a large number of existing seaport tugboats, significantly reducing their emissions in ECA regions such as the Baltic Sea.


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).


Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4023 ◽  
Author(s):  
Stefano d’Ambrosio ◽  
Alessandro Ferrari ◽  
Alessandro Mancarella ◽  
Salvatore Mancò ◽  
Antonio Mittica

An experimental investigation has been carried out to compare the performance and emissions of a low-compression-ratio Euro 5 diesel engine featuring high EGR rates, equipped with different injector technologies, i.e., solenoid, indirect-acting, and direct-acting piezoelectric. The comparisons, performed with reference to a state-of-the-art double fuel injection calibration, i.e., pilot-Main (pM), are presented in terms of engine-out exhaust emissions, combustion noise (CN), and fuel consumption, at low–medium engine speeds and loads. The differences in engine performance and emissions of the solenoidal, indirect-acting, and direct-acting piezoelectric injector setups have been found on the basis of experimental results to mainly depend on the specific features of their hydraulic circuits rather than on the considered injector driving system.


Author(s):  
Kuo Yang ◽  
Pingen Chen

Abstract Engine efficiency improvement is very critical for medium to heavy-duty vehicles to reduce Diesel fuel consumption and enhance U.S. energy security. The tradeoff between engine efficiency and NOx emissions is an intrinsic property that prevents modern Diesel engines, which are generally equipped with exhaust gas recirculation (EGR) and variable geometry turbocharger (VGT), from achieving the optimal engine efficiency while meeting the stringent NOx emission standards. The addition of urea-based selective catalytic reduction (SCR) systems to modern Diesel engine aftertreatment systems alleviate the burden of NOx emission control on Diesel engines, which in return creates extra freedom for optimizing Diesel engine efficiency. This paper proposes two model-based approaches to locate the optimal operating point of EGR and VGT in the air-path loop to maximize the indicated efficiency of turbocharged diesel engine. Simulation results demonstrated that the engine brake specific fuel consumption (BSFC) can be reduced by up to 1.6% through optimization of EGR and VGT, compared to a baseline EGR-VGT control which considers both NOx emissions and engine efficiency on engine side. The overall equivalent BSFCs are 1.8% higher with optimized EGR and VGT control than with the baseline control. In addition, the influence of reducing EGR valve opening on the non-minimum phase behavior of the air path loop is also analyzed. Simulation results showed slightly stronger non-minimum phase behaviors when EGR is fully closed.


2014 ◽  
Vol 119 ◽  
pp. 405-416 ◽  
Author(s):  
S. Molina ◽  
C. Guardiola ◽  
J. Martín ◽  
D. García-Sarmiento

2011 ◽  
Vol 347-353 ◽  
pp. 3915-3919 ◽  
Author(s):  
Jun Liu ◽  
Zhen Bin Chen ◽  
Ming Wei Xiao ◽  
Sheng Jun Jiang

To meet demands for improvements in the CO,NOx and smoke intensity and fuel economy from diesel engine,the emulsified diesel fuel are choose as alternative fuel .It is prepared through selecting appropriate compound-surfactants on the basis of the HLB (hydrophilic and lipop- hilic balance) value.Comparative experiments between the emulsified fuels and diesel are undertook based on engine bench test in the model 295A diesel engine without any modification. The results indicate that smoke intensity and NOx emissions are reduced greatly when using the emulsified fuels ,especially for those with glucose Solution.Besides,The fuel consumption of the emulsified fuels s are less than that of pure diesel and the economy characteristic from diesel engine is better.


In present days industries are growing at a rapid rate and so as the usage of the diesel. The fossil fuels are limited in nature, the increased usage of diesel is resulting in the depletion of its reserves this gives rise to the need of alternative fuels. Due to low specific fuel consumption and supreme power efficiency it has vast applications compared to other fuels but NOX and smoke has seriously causing problem to environment. For this the Palmyra oil has same properties of diesel with varying compression ratios effects the performance and emission characteristics are evaluated. In this process step wise increase of CRs from 16 initially .Then increases EGRs of 0%,5% and 10% and studied performance and emission characteristics. There is improvement in engine efficiency during EGR increment and at low load .There is simultanesly decrease in NOX emissions . The single cylinder four stroke variable compression performance and emissions can be varied.. when fuel is pure diesel,b15and b35 of Palmyra oil is examined and bear with standard automobile usable diesel was conducted at compression ratio of 16:1 at the degrees of 19 and 23 degrees. The influence of Palmyra oil like compression ratio on fuel consumption ,brake thermal efficiency and exhaust gas emissions like NOx and hc has been investigated .the overall optimum is found to be b15 biodiesel –diesel blended for compression ratio of 16 at different exhaust gas recirculation such as 0, 5 and 10. The same experimentation is done for other blends B15 and B35 with palmyra oil. All the values are compared with each other. The configuration which achieved highest Break thermal efficiency is compared to the common diesel engine configuration used and the advantages and the disadvantages are listed out


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