scholarly journals The influence of exhaust system leak on the operating parameters of a turbocharged spark ignition engine

2018 ◽  
Vol 19 (6) ◽  
pp. 468-472
Author(s):  
Krystian Hennek ◽  
Mariusz Graba

Turbocharging of an internal combustion engine is the most common technique to improve an engines’ performance. In present it is not hard to meet vehicles on the road with turbocharged SI engines, which have a high mileage, and because of this fact there is a high risk of exhaust systems leak. This might have its influence not only on the emissions, but also on the vehicles performance. Thereby this dissertation shows the comparative analysis of the influence of exhaust system leak in the catalyzer input on the exhaust gasses composition in the catalyzer output and the operation parameters of an turbocharged SI engine. During the research some parameters were recorded and compared, e. g.: the engines power and torque, the injec-tors opening time, the oxygen sensors voltage signals in the input and in the output of the catalyzer, the concentration of harmful gasses in the exhaust tailpipe. The research was conducted with the use of a single roller MAHA MSR 500 chassis dynamometer. A series of torque measurements was performed. Under these measurements a simulation of the exhaust system leakage of a turbocharged SI passenger car engine was made. As a result three variations of the wideband oxygen sensor acting were reached. The wideband sensor is mounted between the turbocharger unit and the input of the catalyzer. In the test the influence of the leakage on the injector’s opening time and the composition of harmful exhaust substances were pointed.

2005 ◽  
Vol 127 (05) ◽  
pp. 26-29 ◽  
Author(s):  
Peter Huber ◽  
Mark P. Mills

This article highlights that mechanical engineers control most of the rest of our energy economy. The engineering focus will shift inexorably toward finding the most efficient means of generating electricity on-board. Trains and monster trucks both use big diesel generators. Hybrid cars on the road today burn gasoline, but it is the fuel cell that attracts the most attention from visionaries and critics of the internal combustion engine. Remarkably elegant in its basic operation, the fuel cell transforms fuel into electricity in a single step, completely bypassing the furnace, turbine, and generator. In this scenario, mechanical engineering ultimately surrenders its last major under-the-hood citadel to chemical engineers. One might say that the age of mechanical engineering was launched by James Watt's steam engine in 1763, and propelled through its second century by Nikolaus Otto’s 1876 invention of the spark-ignited petroleum engine. We are now at the dawn of the age of electrical engineering, not because we recently learned how to generate light-speed electrical power, but because we have now finally learned how to control it.


2018 ◽  
Vol 19 (6) ◽  
pp. 463-467
Author(s):  
Krystian Hennek ◽  
Mariusz Graba

Paper discussed the influence of exhaust system leakage on the utility parameters and toxic combustion products emission of a turbocharged passenger car spark ignition engine. A comparative analysis of the data gathered in the research carried out using the MAHA MSR 500 single roller chassis dynamometer was conducted, where the exhaust system was sealed and leaking in the area of the wideband oxygen sensor mounting bracket. The presented data refers to among others: the emissions of harmful gasoline oxidation products (HC, CO), the courses of power generated by the engine and the momentary values of excess air ratio. The EUDC driving cycle was used in the research.


Author(s):  
Hailin Li ◽  
Ghazi A. Karim ◽  
A. Sohrabi

The operation of spark ignition (SI) engines on lean mixtures is attractive, in principle, since it can provide improved fuel economy, reduced tendency to knock, and extremely low NOx emissions. However, the associated flame propagation rates become degraded significantly and drop sharply as the operating mixture is made increasingly leaner. Consequently, there exist distinct operational lean mixture limits beyond which satisfactory engine performance cannot be maintained due to the resulting prolonged and unstable combustion processes. This paper presents experimental data obtained in a single cylinder, variable compression ratio, SI engine when operated in turn on methane, hydrogen, carbon monoxide, gasoline, iso-octane, and some of their binary mixtures. A quantitative approach for determining the operational limits of SI engines is proposed. The lean limits thus derived are compared and validated against the corresponding experimental results obtained using more traditional approaches. On this basis, the dependence of the values of the lean mixture operational limits on the composition of the fuel mixtures is investigated and discussed. The operational limit for throttled operation with methane as the fuel is also established.


2013 ◽  
Vol 17 (1) ◽  
pp. 119-133 ◽  
Author(s):  
Jovan Doric ◽  
Ivan Klinar

A zero dimensional model has been used to investigate the combustion performance of a four cylinder petrol engine with unconventional piston motion. The main feature of this new spark ignition (SI) engine concept is the realization of quasi-constant volume (QCV) during combustion process. Presented mechanism is designed to obtain a specific motion law which provides better fuel consumption of internal combustion (IC) engines. These advantages over standard engine are achieved through synthesis of unconventional piston mechanism. The numerical calculation was performed for several cases of different piston mechanism parameters, compression ratio and engine speed. Calculated efficiency and power diagrams are plotted and compared with performance of ordinary SI engine. The results show that combustion during quasi-constant volume has significant impact on improvement of efficiency. The main aim of this paper is to find a proper kinematics parameter of unconventional piston mechanism for most efficient heat addition in SI engines.


2018 ◽  
Vol 3 (11) ◽  
pp. 32-36 ◽  
Author(s):  
Cao Dao Nam ◽  
Van Vang Le

Diesel engines are more efficient than forced ignition engines but due to diffused combustion and work with high air residue levels, burning products contain soot and NOx, pollutants that work Handling it on the road today still has many technical problems. The technology of organizing the combustion of diesel engines directly affects the level of pollution generated. Direct injection diesel engines have a lower fuel consumption than a combustion engine with a separation of about 10% and a lower level of soot emissions when the engine is operating in local loading mode. However, direct injection engines work noisier and generate more pollutants (NOx, HC). Today, this type of combustion chamber is only used for heavy-duty truck engines. Limiting the optimal emission level for diesel engines needs to balance the concentration of the two main pollutants, NOx and soot. Low temperature combustion (LTC) engines need different enabling technologies depending on the fuel and strategy used to achieve combustion of the premixed fuel–air mixture. Controlling the combustion rate is one of the major challenges in LTC engines, particularly in PPCI combustion engine to achieve higher thermal efficiency, the desired phasing of combustion timings is essential even at moderate combustion rates. Present chapter describes the combustion control variables and control strategies used for LTC engines. Various methods demonstrated to control the LTC engines can be categorized in to two main strategies: (i) altering pressure–temperature and (ii) altering fuel reactivity of the charge.


2003 ◽  
Author(s):  
K. Majmudar ◽  
K. Aung

The use of alternative fuels such as methanol and ethanol in spark-ignition (SI) engines is beneficial to the environment as it reduces emissions of pollutants such as NOx from these engines with slight penalty on the performance. This paper investigated the use of liquid fuel blends such as ethanol/gasoline blend in an SI engine by numerical simulations. The numerical simulations were based on the models of finite heat release, cylinder heat transfer, pumping losses, and friction losses. Simulations were carried out to evaluate the effects of compression ratio, equivalence ratio, ignition timing, and engine speed on the performance of the SI engine. The results of the simulations were compared with experimental data from the literature to validate the simulations. Good agreements between the computed and experimental results were obtained. The results showed that the current model could satisfactorily predict the performance of an SI engine fueled by liquid fuel blends.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1769
Author(s):  
Łukasz Rymaniak ◽  
Michalina Kamińska ◽  
Natalia Szymlet ◽  
Rafał Grzeszczyk

The article presents issues related to the assessment of concentrations of harmful substances in the exhaust gas cloud behind the vehicle. In the theoretical part, considerations about the harmfulness of exhaust gases and methods of detection of chemical compounds were made, and the issues of von Karman vortices and the Lambert-Beer law were referred to. The test object was a vehicle equipped with an SI engine meeting the Euro 3 standard. The drive unit had a capacity of 2.8 dm3, a rated power reaching 142 kW at 5500 rpm and a maximum torque of 280 Nm at 3500 rpm. The measurements of the dilution of the exhaust gas cloud behind the vehicle were made in stationary conditions (laboratory) and during actual operation in the Poznań agglomeration. In the research, technically advanced equipment from the PEMS group was used. In the analysis of the obtained results, detailed considerations were made regarding the influence of the location of the measuring probe in relation to the exhaust system. As can be seen from the obtained dependencies, the vehicle motion is favorable for the assessment of concentrations behind a moving object, because the ecological indicators at successive distances behind the exhaust system achieve better parameters in most points than in a stationary test.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Angelo Algieri

The present work aims at analyzing the fluid dynamic efficiency of a four-stroke spark-ignition engine. Specifically, a production four-cylinder internal combustion engine has been investigated during the intake and exhaust phase. The experimental characterization has been carried out at the steady flow rig adopting the dimensionless flow and discharge coefficients. The analysis has highlighted the great influence of the valve lift on the volumetric efficiency of the intake and exhaust system. Furthermore, the global investigation has demonstrated that the throttle angle has a significant influence on the head permeability during the induction phase. Particularly, the throttling process effect increases with the valve lift. Finally, the work has shown that all experimental data can be correlated by a single curve if an opportune dimensionless plot is adopted.


Bio-fuels have been made vital developments from past decades, in which bio-petrol plays a major role in SI engines. Developments in petrol-ethanol blends have been made to improve the efficiency of SI engine. Air preheated is supported widely in preheating of intake air. To improve efficiency and to reduce emission, air preheated is used in many systems. SI engines are used in automobiles, motor cycles, aircrafts, motorboats and portable small engine. In this work, investigations have been done in the SI engine which intakes preheated air-fuel mixture and various blends of ethanol petrol fuel is used as working fuel. Emission tests are done by exhaust gas analyzer to compare the emissions of different fuels.


Author(s):  
V. Matham ◽  
K. Majmudar ◽  
K. Aung

The use of alternative fuels such as natural gas (methane) in spark-ignition (SI) engines is beneficial to the environment as it reduces emissions of pollutants such as NOx from these engines with slight penalty on the performance. This paper investigated the use of methane and hydrogen/methane mixtures in an SI engine by numerical simulations. The numerical simulations were based on the models of finite heat release, cylinder heat transfer, pumping losses, and friction losses. Simulations were carried out to evaluate the effects of compression ratio, equivalence ratio, ignition timing, and engine speed on the performance of the SI engine. The results showed that the current model could satisfactorily predict the performance of an SI engine fueled by gaseous fuels.


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