scholarly journals Performance and Sensitivity analysis of Factors Affecting NOx Emissions from Hydrogen Fueled SI Engine

2016 ◽  
Vol 6 (2) ◽  
pp. 47-74
Author(s):  
Eiman Ali Eh. Sheet

An Analysis of Variance (ANOVA) sensitivity analysis using suitable MATLAB code onthe factors affecting oxides of Nitrogen (NOx) emissions of a hydrogen powered 4-stroke,water-cooled spark-ignition engine was conducted in this work. This was done usingspecialized engine performance and emission simulation software. The parameters studiedwere the engine speed, air-fuel equivalence ratio, spark plug location in addition to some othercombustion parameters like combustion duration, heat loss besides some other usefulperformance parameters. It was found that NOx formation is minimum at peripheral sparklocation, slightly lean (PHI=0.9), and less advance timing is needed. Further, based onANOVA analysis, the combination of engine speed and spark location has more significance(effect based on P-value) compared with engine speed and equivalence ratio. The combinationof engine speed and ignition timing has more significance (effect based on P-value) comparedwith engine speed and equivalence ratio. Also found that NOx emissions behavior is moreclear at lean mixture (PHI = 0.7), central spark location (XSP = 0.5) and retarded ignitiontiming (IGN near zero).

2021 ◽  
Vol 39 (3) ◽  
pp. 919-924
Author(s):  
Ufaith Qadiri ◽  
Amjad Ali Pasha ◽  
Mustafa Mutiur Rahman ◽  
Mohammed Abdul Raheem ◽  
Abdul Gani Abdul Jameel ◽  
...  

In this contribution, the investigation conducted on alternative fuels includes methanol 20% blended with gasoline 80% and emulsion-based fuel with the composition of gasoline 80%, ethanol 15%, and H2O 5% are compared with 100% conventional gasoline fuel. These fueled single-cylinders spark ignition engine is studied for checking their performance and emission characteristics as per future emission norms. This work is performed on One-dimensional AVL Boost Simulation Software. The simulations predicted the performance and emission characteristics were far lesser than conventional 100% gasoline. These fuels meet the strict emission regulations of Euro VII. The main purpose of this investigation is to use alternative fuels to improve the performance and emission characteristics of the single- cylinder spark ignition engine and reduce the consumption of fossil fuel reserves. This investigation led to the conclusion that by using methanol 20% in 80% gasoline and micro-emulsion, fuel improves the power, BSFC (brake specific fuel consumption), thermal efficiency and combustion properties of the single-cylinder spark-ignition engine. The CO, HC and NOx emissions were also reduced for alternative fuel than 100% gasoline fuel. The novel water-based emulsion fuel showed the lowest value of NOx emissions as compared to blended 20% methanol with 80% gasoline and 100% gasoline fuel.


2012 ◽  
Vol 588-589 ◽  
pp. 319-322
Author(s):  
Ye Jian Qian ◽  
Zhi Fang Chen ◽  
Chun Mei Wang

A numerical study is conducted in a port fuel-injection, spark-ignition engine fuelled with 1-butanol at different fuel/air equivalence ratios and inlet air temperatures. The effect of fuel/air equivalence ratio and inlet air temperature on the engine performance and emission characteristics is analyzed. The modeling results show that the incylinder pressure and temperature increases with the increase of fuel/air equivalence ratio. The slightly lean mixtures offer the maximum level of NOX emissions. In addition, preheating the inlet air can increase the incylinder pressure peak value and NOX emissions.


Author(s):  
Jon P. McDonald ◽  
Arthur M. Mellor

Semi–empirical characteristic time models (CTMs) for NOx emissions index (EI) and lean blowoff are used in the design of an inlet condition matrix for measurement of NOxEI from a lean premixed combustor. Such models relate either NOxEI or the weak extinction limit to times representing relevant physical and chemical processes in the combustor. Lean premixed (LP) natural gas/air combustion is considered for the following conditions: inlet temperature, 300–800 K; combustor pressure, 1–30 atm; and equivalence ratio, 0.5–0.7. The NOx model is used to determine combinations of inlet conditions corresponding to greatest NOx sensitivity. A dependence of NOx emissions on pressure is included in the model. Emissions of oxides of nitrogen are found to he most sensitive to variations in inlet temperature and combustor pressure, in the 560–800 K and 20–30 atm ranges, respectively, while sensitivity to variations in equivalence ratio is substantial over the entire range considered. Thus it is found that operating conditions for high thermal efficiency in LP turbine combustors conflict with the goal of lowering NOx emissions, a result consistent with thermal NOx from conventional, diffusion flame combustors. A lean blowoff model is used to estimate the lowest equivalence ratio at which a flame can he held, as well as to determine whether a flame can be stabilised at the operating conditions suggested by the NOx sensitivity analysis. The results suggest a nominal lower limit on equivalence ratio of 0.4, and that a flame can be held for most of the combinations of inlet conditions suggested by the NOx sensitivity analysis. Autoignition of the fuel/air mixture is also considered in relation to the location and/or design of the premixing system. The current NOx CTM is applied to LP natural gas fired data from the literature. A model modification, thought to better represent the fluid mechanics relevant to LP NOx formation, is applied, and its implications discussed.


Author(s):  
Masoud Iranmanesh ◽  
J. P. Subrahmanyam ◽  
M. K. G. Babu

In this investigation, tests were conducted on a single cylinder DI diesel engine fueled with neat diesel and biodiesel as baseline fuel with addition of 5 to 20% DEE on a volume basis in steps of 5 vol.% as supplementary oxygenated fuel to analyze the simultaneous reduction of smoke and oxides of nitrogen. Some physicochemical properties of test fuels such as heating value, viscosity, specific gravity and distillation profile were also determined in accordance to the ASTM standards. The results obtained from the engine tests have shown a significant reduction in NOX emissions especially for biodiesel and a little decrease in smoke of DEE blends compared with baseline fuels. A global overview of the results has shown that the 5% DEE-Diesel fuel and 15% DEE-Biodiesel blend are the optimal blend based on performance and emission characteristics.


2017 ◽  
Vol 79 (7-4) ◽  
Author(s):  
Muhammad Hariz Khairuddin ◽  
Muhammad Fitri Shamsul Bahri ◽  
Afiq Aiman Dahlan ◽  
Mahadhir Mohammad ◽  
Mohd Farid Muhamad Said

Intake manifold system is one of the important component in the engine system which functions to evenly distribute the air flows into every cylinder of the engine. With the restricted air intake rule regulation, the intake air system for a car must be properly design in order to minimize the performance dropped caused by the restrictor. The paper presents the study on the effects of intake design parameter towards the performance of the engine and then improves the performance of previous intake manifold system. This study starts with the development of Honda CBR 600RR engine model and intake manifold system model using GT-Power engine simulation software to be used for the simulation purposes. After developing the reference engine model, the parametric study was carried out to study the effect of the intake manifold parameter design on the engine performance. The optimization process was then performed to achieve the target of improvement which has already been set prior to performing the optimization. The final results show an increase up to 4.83% and 4.45% of torque and air flow rate respectively at the desired operating range of engine speed.


Author(s):  
İsmet Sezer ◽  
Atilla Bilgin

This study aims at the theoretical exergetic evaluation of spark ignition engine operation. For this purpose, a two-zone quasi-dimensional cycle model was installed, not considering the complex calculation of fluid motions. The cycle simulation consists of compression, combustion and expansion processes. The combustion phase is simulated as a turbulent flame propagation process. Intake and exhaust processes are also computed by a simple approximation method. The results of the model were compared with experimental data to demonstrate the validation of the model. Principles of the second law are applied to the model to perform the exergy (or availability) analysis. In the exergy analysis, the effects of various operational parameters, i.e. fuel–air equivalence ratio, engine speed and spark timing on exergetic terms have been investigated. The results of exergy analysis show that variations of operational parameters examined have considerably affected the exergy transfers, irreversibilities and efficiencies. For instance, an increase in equivalence ratio causes an increase in irreversibilities, while it decreases the first and also the second law efficiencies. The irreversibilities have minimum values for the specified engine speed and optimum spark timing, while the first and second law efficiencies reach a maximum at the same engine speed and optimum spark timing.


1991 ◽  
Vol 113 (3) ◽  
pp. 377-381 ◽  
Author(s):  
R. W. Rice ◽  
A. K. Sanyal ◽  
A. C. Elrod ◽  
R. M. Bata

Emissions levels for CO, NOx, and unburned fuel (UBF) from a stationary four-cylinder Chrysler engine were measured under a variety of operating conditions for gasoline and three different 20 vol percent alcohol-gasoline blends. In tests of separate isobutanol, ethanol, and methanol blends, lower CO and NOx emissions were observed for the alcohol blends relative to gasoline, particularly for fuel-rich operation. Generally, on a volume (mole) basis unburned fuel emissions were highest for methanol blends and lowest for gasoline, but on a mass or OMHCE basis only small differences were noted. For a given fuel, the separate effects of engine speed, load, and equivalence ratio were examined.


Author(s):  
Zhanguang Wang ◽  
Song Zhou ◽  
Yongming Feng ◽  
Yuanqing Zhu

In 2016, the International Maritime Organization (IMO) has enforced stricter nitrogen oxide (NOx) emission standards. Exhaust gas recirculation (EGR) technology is an effective way to achieve IMO Tier III standards for two-stroke marine diesel engines. This paper selected the 6S50ME-C8.2 diesel engine for the study, by making use of GT-POWER simulation software. In this paper, three different types of EGR were built to investigate the effects of EGR on engine performance and NOx emissions. The results show that both the high pressure EGR system and the low pressure EGR system can reduce NOx emissions with the power drop and BSFC risen. While in the high pressure EGR system combined with EGB, more NOx can be reduced with less power drop and BSFC risen. What is more, the running points of the compressor are still in the high efficient area and away the surge margin. Based on the conclusions, the results obtained in this paper can offer reference for the turbocharged diesel engines with EGR system to reduce NOx emissions and improve engine performance.


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