scholarly journals The effect of alternative fuels injection timing on toxic substances formation in CI engines

2017 ◽  
Vol 168 (1) ◽  
pp. 73-76
Author(s):  
Marcin WOJS ◽  
Piotr ORLIŃSKI ◽  
Jakub LASOCKI

The present study describes selected issues associated with the emission level in toxic exhaust gases and fuel injection timing. The study was focused on the following types of fuels: Diesel oil (the base fuel) and the other fuels were the mixture of fatty acid methyl ester with Camelina (L10 – diesel fuel with 10% V/V FAME of Camelina and L20 – diesel fuel with 10% V/V FAME of Camelina) was used. Fuel injection advanced angle was set for three different values – the factory setting – 12° before TDC, later injection – 7° and earlier injection – 17°. The most important conclusion is that in most measurement points registered in the same engine operating conditions, the concentration of fuel NOx in L10 and L20 increased but PM emissions decreased which is caused by active oxygen located in the internal structure of the fuel. This fact contributes to the rise in temperature during the combustion process. At the same time factory settings of the angle makes NOx emissions lower and close to reference fuel.

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Adam Klingbeil ◽  
Seunghyuck Hong ◽  
Roy J. Primus

Abstract Experiments were conducted on a large bore, medium speed, single cylinder, diesel engine to investigate operation with substitution ratio of natural gas (NG) varying from 0% to 93% by energy. In a previous study by the same group, these data were used to validate an analytical methodology for predicting performance and emissions under a broad spectrum of energy substitution ratios. For this paper, these experimental data are further analyzed to better understand the performance and combustion behavior under NG substitution ratios of 0%, 60%, and 93%. These results show that by transitioning from diesel-only to 60% dual-fuel (DF) (60% NG substitution ratio), an improvement in the NOx-efficiency trade-off was observed that represented a ∼3% improvement in indicated efficiency at constant NOx. Further, the transition from 60% DF to 93% DF (93% NG substitution ratio) resulted in additional efficiency improvement with a simultaneous reduction in NOx emissions. The data suggest that this improvement can be attributed to the premixed nature of the high substitution ratio case. Furthermore, the results show that high cycle-to-cycle variation was observed for some 93% DF combustion tests. Further analysis, along with diesel injection rate measurements, shows that the observed extreme sensitivity of the combustion event can be attributed to critical parameters such as diesel fuel quantity and injection timing. These results suggest a better understanding of the relative importance of combustion system components and operating conditions in controlling cycle-to-cycle variation of combustion process.


2019 ◽  
Vol 9 (3) ◽  
pp. 484 ◽  
Author(s):  
Giorgio Zamboni

Indicated pressure diagrams were measured during experimental campaigns on the control of fuel injection, turbocharging and hybrid exhaust gas recirculation systems in an automotive downsized diesel engine. Three-part load operating conditions were selected for four test sets, where strategies aimed at the reduction of NOX emissions and fuel consumption, limiting penalties in soot emissions and combustion noise were applied to the selected systems. Processing of in-cylinder pressure signal, its first derivative and curves of the rate of heat release allowed us to evaluate seven parameters related to the combustion centre and duration, maximum values of pressure, heat release and its first derivative, heat released in the premixed phase and a combustion noise indicator. Relationships between these quantities and engine operating, energy and environmental parameters were then obtained by referring to the four test sets. In the paper, the most significant links are presented and discussed, aiming at a better understanding of the influence of control variables on the combustion process and the effects on engine behaviour. The proposed methodology proved to be a consistent tool for this analysis, useful for supporting the application of alternative fuels or advanced combustion modes.


Author(s):  
Raavi Peraiah Chowdary ◽  
Maddali V. S. Murali Krishna ◽  
T. Kishen Kumar Reddy ◽  
D. Srikanth ◽  
P. V. Krishna Murthy ◽  
...  

Biodiesels derived from vegetable oils present a very promising alternative fuels for diesel fuel, since they have numerous advantages compared to fossil fuels. However crude vegetable oil and biodiesel have high viscosity and low volatility causing combustion problems in CI engines, call for engine with hot combustion chamber. Investigations were carried out on single–cylinder, four–stroke, water cooled, 3.68 kW direct injection diesel engine at a speed of 1500 rpm to evaluate the performance of a engine with low heat rejection (LHR) combustion chamber. It consisted of an air gap (3 mm) insulated piston with superni (an alloy of nickel) crown and an air gap (3 mm) insulated liner with superni insert and ceramic coated cylinder head fuelled with different operating conditions (normal temperature and preheated temperature) of waste fried vegetable oil and its biodiesel with varied injection timing and injector opening pressure. Engine with LHR combustion chamber with biodiesel showed improved performance over conventional engine (CE) at 27° bTDC and at optimum injection timing. Biodiesel showed improved performance over crude vegetable oil with engine with both versions of the combustion chamber. Preheated test fuels and increase of injection pressure showed reduction of pollution levels and marginally improved performance over normal test fuels.


2015 ◽  
Vol 813-814 ◽  
pp. 857-861
Author(s):  
A.N. Basavaraju ◽  
Mallikappa ◽  
B. Yogesha

The present energy situation has stimulated active research interest in non-petroleum and non-polluting fuels, particularly for transportation, power generation, and agricultural sectors. This paper describes feasibility of utilization of Spark ignition (SI) engine in single fuel mode and to develop the optimum operating conditions in terms of fuel injection timing and fuel injection pressure. Many modifications were made for the developed direct fuel injection system to improve the performance of the 350 cc four stroke single cylinder petrol engine. The engine is tested to conduct performance, combustion emission characteristics with the aid of carburetor. As single cylinder small engines have low compression ratio (CR), and they run with slightly rich mixture, their power are low and emission values are high. In this study, methanol was used to increase performance and decrease emissions of a single-cylinder engine. Initially, the engine whose CR was 7.5/1 was tested with gasoline and methanol at full load and various speeds. This method is used for increasing the fuel efficiency of a vehicle by adding different percentage of methanol to the petrol and to decrease the pollutants produced during combustion process.


2014 ◽  
Vol 18 (1) ◽  
pp. 143-153
Author(s):  
Ivan Filipovic ◽  
Boran Pikula ◽  
Goran Kepnik

One of the alternative fuels, originating from renewable sources, is biodiesel fuel, which is introduced in diesel engines without major construction modifications on the engine. Biodiesel fuel, by its physical and chemical properties, is different from diesel fuel. Therefore, it is expected that by the application of a biodiesel fuel, the characteristic parameters of the injection system will change. These parameters have a direct impact on the process of fuel dispersion into the engine cylinder, and mixing with the air, which results in an impact on the quality of the combustion process. Method of preparation of the air-fuel mixture and the quality of the combustion process directly affect the efficiency of the engine and the level of pollutant emissions in the exhaust gas, which today is the most important criterion for assessing the quality of the engine. The paper presents a detailed analysis of the influence of physical properties of a mixture of diesel and biodiesel fuels on the output characteristics of the fuel injection system. The following parameters are shown: injection pressure, injection rate, the beginning and duration of injection, transformation of potential into kinetic energy of fuel and increase of energy losses in fuel injection system of various mixtures of diesel and biodiesel fuels. For the analysis of the results a self-developed computer program was used to simulate the injection process in the system. Computational results are verified using the experiment, for a few mixtures of diesel and biodiesel fuels. This paper presents the verification results for diesel fuel and biodiesel fuel in particular.


1992 ◽  
Vol 114 (3) ◽  
pp. 488-495 ◽  
Author(s):  
V. O. Markworth ◽  
S. G. Fritz ◽  
G. R. Cataldi

An experimental study was performed to demonstrate the fuel economy and exhaust emissions implications of retarding fuel injection timing, enhancing charge air aftercooling, and using low-sulfur, low-aromatic diesel fuel for locomotive engines. Steady-state gaseous and particulate emissions data are presented from two 12-cylinder diesel locomotive engines. The two laboratory engines, an EMD 645E3B and a GE 7FDL, are each rated at 1860 kW (2500 hp) and represent the majority of the locomotive fleet in North America. Each engine was tested for total hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx), and particulate. Emissions were measured at three steady-state operating conditions: rated speed and load, idle, and an intermediate speed and load. Test results on the EMD engine indicate that a 4 deg injection timing retard, along with a low-sulfur, low-aromatic fuel and enhanced aftercooling, was effective in reducing NOx from 10.5 g/hp-h to 7.2 g/hp-h; however, particulates increased from 0.15 g/hp-h to 0.19 g/hp-h, and fuel efficiency was 4.3 percent worse. Similar observations were made with the GE engine. This paper gives details on the test engines, the measurement procedures, and the emissions results.


Author(s):  
Shuonan Xu ◽  
David Anderson ◽  
Mark Hoffman ◽  
Robert Prucka ◽  
Zoran Filipi

Energy security concerns and an abundant supply of natural gas in the USA provide the impetus for engine designers to consider alternative gaseous fuels in the existing engines. The dual-fuel natural-gas diesel engine concept is attractive because of the minimal design changes, the ability to preserve a high compression ratio of the baseline diesel, and the lack of range anxiety. However, the increased complexity of a dual-fuel engine poses challenges, including the knock limit at a high load, the combustion instability at a low load, and the transient response of an engine with directly injected diesel fuel and port fuel injection of compressed natural gas upstream of the intake manifold. Predictive simulations of the complete engine system are an invaluable tool for investigations of these conditions and development of dual-fuel control strategies. This paper presents the development of a phenomenological combustion model of a heavy-duty dual-fuel engine, aided by insights from experimental data. Heat release analysis is carried out first, using the cylinder pressure data acquired with both diesel-only and dual-fuel (diesel and natural gas) combustion over a wide operating range. A diesel injection timing correlation based on the injector solenoid valve pulse widths is developed, enabling the diesel fuel start of injection to be detected without extra sensors on the fuel injection cam. The experimental heat release trends are obtained with a hybrid triple-Wiebe function for both diesel-only operation and dual-fuel operation. The ignition delay period of dual-fuel operation is examined and estimated with a predictive correlation using the concept of a pseudo-diesel equivalence ratio. A four-stage combustion mechanism is discussed, and it is shown that a triple-Wiebe function has the ability to represent all stages of dual-fuel combustion. This creates a critical building block for modeling a heavy-duty dual-fuel turbocharged engine system.


2017 ◽  
Vol 19 (2) ◽  
pp. 202-213 ◽  
Author(s):  
Michal Pasternak ◽  
Fabian Mauss ◽  
Christian Klauer ◽  
Andrea Matrisciano

A numerical platform is presented for diesel engine performance mapping. The platform employs a zero-dimensional stochastic reactor model for the simulation of engine in-cylinder processes. n-Heptane is used as diesel surrogate for the modeling of fuel oxidation and emission formation. The overall simulation process is carried out in an automated manner using a genetic algorithm. The probability density function formulation of the stochastic reactor model enables an insight into the locality of turbulence–chemistry interactions that characterize the combustion process in diesel engines. The interactions are accounted for by the modeling of representative mixing time. The mixing time is parametrized with known engine operating parameters such as load, speed and fuel injection strategy. The detailed chemistry consideration and mixing time parametrization enable the extrapolation of engine performance parameters beyond the operating points used for model training. The results show that the model responds correctly to the changes of engine control parameters such as fuel injection timing and exhaust gas recirculation rate. It is demonstrated that the method developed can be applied to the prediction of engine load–speed maps for exhaust NOx, indicated mean effective pressure and fuel consumption. The maps can be derived from the limited experimental data available for model calibration. Significant speedup of the simulations process can be achieved using tabulated chemistry. Overall, the method presented can be considered as a bridge between the experimental works and the development of mean value engine models for engine control applications.


2021 ◽  
pp. 146808742110464
Author(s):  
Yang Hua

Ether and ester fuels can work in the existing internal combustion (IC) engine with some important advantages. This work comprehensively reviews and summarizes the literatures on ether fuels represented by DME, DEE, DBE, DGM, and DMM, and ester fuels represented by DMC and biodiesel from three aspects of properties, production and engine application, so as to prove their feasibility and prospects as alternative fuels for compression ignition (CI) and spark ignition (SI) engines. These studies cover the effects of ether and ester fuels applied in the form of single fuel, mixed fuel, dual-fuel, and multi-fuel on engine performance, combustion and emission characteristics. The evaluation indexes mainly include torque, power, BTE, BSFC, ignition delay, heat release rate, pressure rise rate, combustion duration, exhaust gas temperature, CO, HC, NOx, PM, and smoke. The results show that ethers and esters have varying degrees of impact on engine performance, combustion and emissions. They can basically improve the thermal efficiency of the engine and reduce particulate emissions, but their effects on power, fuel consumption, combustion process, and CO, HC, and NOx emissions are uncertain, which is due to the coupling of operating conditions, fuel molecular structure, in-cylinder environment and application methods. By changing the injection strategy, adjusting the EGR rate, adopting a new combustion mode, adding improvers or synergizing multiple fuels, adverse effects can be avoided and the benefits of oxygenated fuel can be maximized. Finally, some challenges faced by alternative fuels and future research directions are analyzed.


2015 ◽  
Vol 4 (1) ◽  
pp. 1-10 ◽  
Author(s):  
D.N. Basavarajappa ◽  
N. R. Banapurmath ◽  
S.V. Khandal ◽  
G. Manavendra

For economic and social development of any country energy is one of the most essential requirements. Continuously increasing price of crude petroleum fuels in the present days coupled with alarming emissions and stringent emission regulations has led to growing attention towards use of alternative fuels like vegetable oils, alcoholic and gaseous fuels for diesel engine applications. Use of such fuels can ease the burden on the economy by curtailing the fuel imports. Diesel engines are highly efficient and the main problems associated with them is their high smoke and NOx emissions.  Hence there is an urgent need to promote the use of alternative fuels in place of high speed diesel (HSD) as substitute. India has a large agriculture base that can be used as a feed stock to obtain newer fuel which is renewable and sustainable. Accordingly Uppage oil methyl ester (UOME) biodiesel was selected as an alternative fuel. Use of biodiesels in diesel engines fitted with mechanical fuel injection systems has limitation on the injector opening pressure (300 bar). CRDI system can overcome this drawback by injecting fuel at very high pressures (1500-2500 bar) and is most suitable for biodiesel fuels which are high viscous. This paper presents the performance and emission characteristics of a CRDI diesel engine fuelled with UOME biodiesel at different injection timings and injection pressures. From the experimental evidence it was revealed that UOME biodiesel yielded overall better performance with reduced emissions at retarded injection timing of -10° BTDC in CRDI mode of engine operation.


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