Effect of Engine Variables on Combustion Performance of Lean Burn Spark Ignition Engine: An Overview

Author(s):  
A. Manivannan ◽  
R. Ramprabhu

In the development of internal combustion engines, there has been a continuous effort to reduce fuel consumption and exhaust emissions. Lean combustion is a preferred concept for reducing exhaust emissions for meeting stringent emission standards. However lean combustion is associated with increased cycle-by-cycle combustion variation due to combustion instability. The combustion stability under lean mixture conditions could be improved through enhancement of flow characteristics. Effect of engine variables on lean combustion of Spark Ignition (SI) engine is presented, including combustion chamber and inlet port configuration, and ignition system. Use of pre-chamber for lean combustion is one of the feasible method to achieve stable ignition and quick flame propagation. This paper highlights and compares status of various research works carried out in the area of lean burn engines. A critical analysis of reported experimental data is presented in order to substantiate use of lean combustion in SI engine.

2021 ◽  
pp. 146808742110346
Author(s):  
Sanguk Lee ◽  
Gyeonggon Kim ◽  
Choongsik Bae

Hydrogen can be used as a fuel for internal combustion engines to realize a carbon-neutral transport society. By extending the lean limit of spark ignition engines, their efficiency, and emission characteristics can be improved. In this study, stratified charge combustion (SCC) using monofueled hydrogen direct injection was used to extend the lean limit of a spark ignition engine. The injection and ignition timing were varied to examine their effect on the SCC characteristics. An engine experiment was performed in a spray-guided single-cylinder research engine, and the nitrogen oxide and particulate emissions were measured. Depending on the injection timing, two different types of combustion were characterized: mild and hard combustion. The advancement and retardation of the ignition timing resulted in a high and low combustion stability, respectively. The lubricant-based particulate emission was attributed to the in-cylinder temperature and area of the flame surface. Therefore, the results of the study suggest that the optimization of the hydrogen SCC based on the injection and ignition timing could contribute to a clean and efficient transport sector.


Author(s):  
T. Shudo ◽  
H. Oka

Hydrogen is a clean alternative to fossil fuels for internal combustion engines and can be easily used in spark-ignition engines. However, the characteristics of the engines fueled with hydrogen are largely different from those with conventional hydrocarbon fuels. A higher burning velocity and a shorter quenching distance for hydrogen as compared with hydrocarbons bring a higher degree of constant volume and a larger heat transfer from the burning gas to the combustion chamber wall of the engines. Because of the large heat loss, the thermal efficiency of an engine fueled with hydrogen is sometimes lower than that with hydrocarbons. Therefore, the analysis and the reduction of the heat loss are crucial for the efficient utilization of hydrogen in internal combustion engines. The empirical correlations to describe the total heat transferred from the burning gas to the combustion chamber walls are often used to calculate the heat loss in internal combustion engines. However, the previous research by one of the authors has shown that the widely used heat transfer correlations cannot be properly applied to the hydrogen combustion even with adjusting the constants in them. For this background, this research analyzes the relationship between characteristics of thermophysical properties of working substance and heat transfer to the wall in a spark-ignition engine fueled with hydrogen.


Author(s):  
Lorenzo Gasbarro ◽  
Jinlong Liu ◽  
Christopher Ulishney ◽  
Cosmin E. Dumitrescu ◽  
Luca Ambrogi ◽  
...  

Abstract Investigations using laboratory test benches are the most common way to find the technological solutions that will increase the efficiency of internal combustion engines and curtail their emissions. In addition, the collected experimental data are used by the CFD community to develop engine models that reduce the time-to-market. This paper describes the steps made to increase the reliability of engine experiments performed in a heavy-duty natural-gas spark-ignition engine test-cell such as the design of the control and data acquisition system based on Modbus TCP communication protocol. Specifically, new sensors and a new dynamometer controller were installed. The operation of the improved test bench was investigated at several operating conditions, with data obtained at both high- and low-sampling rates. The results indicated a stable test bench operation.


2021 ◽  
Vol 11 (13) ◽  
pp. 6035
Author(s):  
Luigi Teodosio ◽  
Luca Marchitto ◽  
Cinzia Tornatore ◽  
Fabio Bozza ◽  
Gerardo Valentino

Combustion stability, engine efficiency and emissions in a multi-cylinder spark-ignition internal combustion engines can be improved through the advanced control and optimization of individual cylinder operation. In this work, experimental and numerical analyses were carried out on a twin-cylinder turbocharged port fuel injection (PFI) spark-ignition engine to evaluate the influence of cylinder-by-cylinder variation on performance and pollutant emissions. In a first stage, experimental tests are performed on the engine at different speed/load points and exhaust gas recirculation (EGR) rates, covering operating conditions typical of Worldwide harmonized Light-duty vehicles Test Cycle (WLTC). Measurements highlighted relevant differences in combustion evolution between cylinders, mainly due to non-uniform effective in-cylinder air/fuel ratio. Experimental data are utilized to validate a one-dimensional (1D) engine model, enhanced with user-defined sub-models of turbulence, combustion, heat transfer and noxious emissions. The model shows a satisfactory accuracy in reproducing the combustion evolution in each cylinder and the temperature of exhaust gases at turbine inlet. The pollutant species (HC, CO and NOx) predicted by the model show a good agreement with the ones measured at engine exhaust. Furthermore, the impact of cylinder-by-cylinder variation on gaseous emissions is also satisfactorily reproduced. The novel contribution of present work mainly consists in the extended numerical/experimental analysis on the effects of cylinder-by-cylinder variation on performance and emissions of spark-ignition engines. The proposed numerical methodology represents a valuable tool to support the engine design and calibration, with the aim to improve both performance and emissions.


2017 ◽  
Vol 1 (9) ◽  
pp. 1991-2005 ◽  
Author(s):  
Dominik Gschwend ◽  
Patrik Soltic ◽  
Philip Edinger ◽  
Alexander Wokaun ◽  
Frédéric Vogel

In light of climate change and the fact that surface transportation heavily relies on internal combustion engines, many different alternatives to gasoline have been proposed.


Author(s):  
Timothy J. Jacobs ◽  
Louis J. Camilli ◽  
Joseph E. Gonnella

This article describes a study involving new spark plug technology, referred to as pulsed energy spark plug, for use in igniting fuel-air mixtures in a spark ignition internal combustion engine. The study involves precisely controlled constant volume combustion bomb tests. The major defining difference between the pulsed energy spark plug and a conventional spark plug is a peaking capacitor that improves the electrical-to-plasma energy transfer efficiency from a conventional plug’s 1% to the pulsed energy plug’s 50%. Such an increase in transfer efficiency is believed to improve spark energy and subsequently the ignition time and burn rate of a homogeneous, or potentially stratified, fuel-air mixture. The study observes the pulsed energy plug to shorten the ignition delay of both stoichiometric and lean mixtures (with equivalence ratio of 0.8), relative to a conventional spark plug, without increasing the burn rate. Additionally, the pulsed energy plug demonstrates a decreased lean flammability limit that is about 14% lower (0.76 for conventional plug and 0.65 for pulsed energy plug) than that of the conventional spark plug. These features — advanced ignition of stoichiometric and lean mixtures and decreased lean flammability limits — might qualify the pulsed energy plugs as an enabling technology to effect the mainstream deployment of advanced, ultra-clean and ultra-efficient, spark ignition internal combustion engines. For example, the pulsed energy plug may improve ignition of stratified-GDI engines. Further, the pulsed energy plug technology may improve the attainability of lean-burn homogeneous charge compression ignition combustion by improving the capabilities of spark-assist. Finally, the pulsed energy plug could improve natural gas spark ignition engine development by improving the ignition system. Future work could center efforts on evaluating this spark plug technology in the context of advanced internal combustion engines, to transition the state of the art to the next level.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3356
Author(s):  
Krzysztof Biernat ◽  
Izabela Samson-Bręk ◽  
Zdzisław Chłopek ◽  
Marlena Owczuk ◽  
Anna Matuszewska

This research paper studied the environmental impact of using methane fuels for supplying internal combustion engines. Methane fuel types and the methods of their use in internal combustion engines were systematized. The knowledge regarding the environmental impact of using methane fuels for supplying internal combustion engines was analyzed. The authors studied the properties of various internal combustion engines used for different applications (specialized engines of power generators—Liebherr G9512 and MAN E3262 LE212, powered by biogas, engine for road and off-road vehicles—Cummins 6C8.3, in self-ignition, original version powered by diesel fuel, and its modified version—a spark-ignition engine powered by methane fuel) under various operating conditions in approval tests. The sensitivity of the engine properties, especially pollutant emissions, to its operating states were studied. In the case of a Cummins 6C8.3 modified engine, a significant reduction in the pollutant emission owing to the use of methane fuel, relative to the original self-ignition engine, was found. The emission of carbon oxide decreased by approximately 30%, hydrocarbons by approximately 70% and nitrogen oxide by approximately 50%, as well as a particulate matter emission was also eliminated. Specific brake emission of carbon oxide is the most sensitive to the operating states of the engine: 0.324 for a self-ignition engine and 0.264 for a spark-ignition engine, with the least sensitive being specific brake emission of nitrogen oxide: 0.121 for a self-ignition engine and 0.097 for a spark-ignition engine. The specific brake emission of carbon monoxide and hydrocarbons for stationary engines was higher in comparison with both versions of Cummins 6C8.3 engine. However, the emission of nitrogen oxide for stationary engines was lower than for Cummins engines.


Author(s):  
Vahid Hosseini ◽  
M. David Checkel

Homogenous Charge Compression Ignition (HCCI) combustion is an efficient operating mode for internal combustion engines operating at low specific power and has the further advantage of very low specific NOx emission rate. High Compression Lean Burn (HCLB) spark ignition (SI) provides a more conventional approach to achieving high engine efficiency. Specific NOx emission rates are low though not as low as with HCCI. Compared with HCCI engines, HCLB-SI engines have the advantage of direct combustion control, (through spark timing), and thus are able to start from cold and operate over a wider range of conditions including higher specific power than HCCI. On the other hand HCCI still has the advantage in efficiency and NOx emission rate. These trade-offs makes it desirable to develop an engine which can operate in either mode, hopefully without significantly adding to engine cost or compromising either mode. This paper presents a first exploration of a dual-mode engine which can use either HCCI or HCLB mode by operating on either a base, low-octane liquid fuel or on reformer gas (RG) produced by steam reforming or partial oxidation from the base fuel. Engine experiments with a CFR engine are used to demonstrate engine operation in both HCLB-SI and HCCI operating modes fueled with some combination of n-heptane and reformer gas. The combustion characteristics including combustion stability and cyclic variation are measured and compared for HCCI operation and RG-fueled HCLB-SI engine operation. CNG-fueled SI engine operation is also used as an additional basis for comparison.


Author(s):  
S Sathyanarayanan ◽  
S Suresh ◽  
M Sridharan

Abstract In this study, experimental attempts are made to reduce exhaust gas toxic emission from the spark ignition (SI) engine. For this, a sucrose catalyst is coated inside the metallic substrate. The obtained emission level was compared with the results of commercial catalysts for lean-burn operations. The engine was operated at 20%, 40%, 60%, 80% and 100% loads and the highest NOx conversion efficiency of 60.217% at 40% engine load and 70.732% of HC conversion efficiency at 100% engine loadwas achieved. Exhaust emissions from the sucrose-coated catalytic converterare observed as lower than the conventional commercial converter. Also, this paper attempts to predict the emission characteristics of both rigskept under observation using a fuzzy logic expert system (FLES). Both the input and output responses from the real-time SI engine is used to train and test the proposed FLES. The FLES proposed in this study can predict the emission characteristicsof both conventional and sucrose coated catalytic converter with an accuracy of 97%.


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