The Experts below are selected from a list of 3486 Experts worldwide ranked by ideXlab platform
Guven Gonca - One of the best experts on this subject based on the ideXlab platform.
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Performance Analysis and Simulation of a Diesel-Miller Cycle (DiMC) Engine
Arabian Journal for Science and Engineering, 2019Co-Authors: Guven Gonca, Mehmet Fatih HocaogluAbstract:A comprehensive performance examination of an engine running on combination of the Diesel and Miller Cycles called Diesel-Miller Cycle in terms of effective power, density of the effective power, and effective thermal efficiency, which will be called engine performance (ENPER) characteristics, is conducted using a novel thermodynamic simulation model. The impacts of Cycle design parameters such as Cycle pressure ratio, equivalence ratio, effective compression ratio ( r ), bore/stroke ratio ( d / L ), average piston speed, friction coefficient, engine speed ( N ), stroke ( L ), and air inlet temperature and air inlet pressure on the ENPER characteristics have been investigated. Additionally, the energy losses depending on exhaust output, friction, incomplete combustion, heat transfer have been defined as a ratio of energy provided by fuel injection. Variable specific heat values with respect to temperature variation for working fluid are used to get realistic results. The results of the study are reasonable and unique, and they could be utilized by researchers and engineers studying on internal combustion engines.
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Thermo-Ecological Analysis of Irreversible Dual-Miller Cycle (DMC) Engine Based on the Ecological Coefficient of Performance (ECOP) Criterion
Iranian Journal of Science and Technology Transactions of Mechanical Engineering, 2017Co-Authors: Guven GoncaAbstract:In this paper, an ecological-based numerical analysis and optimization have been carried out for an air-standard irreversible Dual-Miller Cycle engine with late inlet valve closing version using the ecological coefficient of performance (ECOP) criterion which covers finite rate of heat transfer, heat leak and internal irreversibilities. A detailed computational analysis has been performed in order to examine the general and optimum performances of the Cycle. The results obtained based on ECOP function are compared with a different ecological function and with the maximum power output conditions. The consequences of ECOP, ecological function and maximum power output conditions are acquired based on the compression ratio, cut-off ratio, pressure ratio, Miller Cycle ratio, source temperature ratio and internal irreversibility parameter. The influences of these parameters on the optimum performances are examined in detail.
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An Optimization Study on an Eco-Friendly Engine Cycle Named as Dual-Miller Cycle (DMC) for Marine Vehicles
Walter de Gruyter GmbH, 2017Co-Authors: Guven GoncaAbstract:Abstract The diesel engine is an indispensable part of technology and it is commonly used in land and marine vehicles. However, diesel engines release NOx emissions due to high combustion temperatures. They have harmful effects on the environment such as sources of photo-chemical fog and climate changes. Therefore, they must be reduced and limited. The Miller Cycle application is a NOx control method and it is popular in the recent years to abate NOx produced from the internal combustion engines (ICEs). A performance investigation of a Dual-Miller Cycle (DMC) engine in terms of power (PO), power density (PD) and effective efficiency (EE) has been performed using a new finite-time thermodynamics modeling (FTTM) in this study. The effects of engine design and operating parameters on the engine performance (EPER) have been examined. Additionally, the energy losses have been determined resulting from incomplete combustion (IC), friction (FR), heat transfer (HT) and exhaust output (EO). The results presented could be an essential tool for DMC marine engine designers.
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effect of turbo charging and steam injection methods on the performance of a Miller Cycle diesel engine mcde
Applied Thermal Engineering, 2017Co-Authors: Guven Gonca, Bahri SahinAbstract:Abstract In this study, application of the steam injection method (SIM), Miller Cycle (MC) and turbo charging (TC) techniques into a four stroke, direct-injection diesel engine has been numerically and empirically conducted. NOx emissions have detrimental influences on the environment and living beings. They are formed at the high temperatures, thus the Diesel engines are serious NOx generation sources since they have higher compression ratios and higher combustion temperatures. The international regulations have decreased the emission limits due to environmental reasons. The Miller Cycle (MC) application and steam injection method (SIM) have been popular to abate NOx produced from the internal combustion engines (ICEs), in the recent years. However, the MC application can cause a reduction in power output. The most known technique which maximizes the engine power and abates exhaust emissions is TC. Therefore, if these three techniques are combined, the power loss can be tolerated and pollutant emissions can be minimized. While the application of the MC and SIM causes to diminish in the brake power and brake thermal efficiency of the engine up to 6.5% and 10%, the TC increases the brake power and brake thermal efficiency of the engine up to 18% and 12%. The experimental and theoretical results have been compared in terms of the torque, the specific fuel consumption (SFC), the brake power and the brake thermal efficiency. The results acquired from theoretical modeling have been validated with empirical data with less than 7% maximum error. The results showed that developed combination can increase the engine performance and the method can be easily applied to the Diesel engines.
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investigation of the effects of the steam injection method sim on the performance and emission formation of a turbocharged and Miller Cycle diesel engine mcde
Energy, 2017Co-Authors: Guven Gonca, Bahri Sahin, Adnan Parlak, Vezir Ayhan, Idris Cesur, Sakip KoksalAbstract:Abstract The steam injection method (SIM) has been widespread to abate NOx of internal combustion engines (ICEs). Another NOx reduction method known in the literature is the Miller Cycle (MC) application. However, this method causes a reduction in the power output. The most known technique which improves the engine power and decreases emissions is the turbo charging (TC). Hence, these three methods can be combined to make up for the power loss and to decrease pollutant emissions at higher rates. In this study, the combination of the SIM, TC and MC methods (SIM-TC-MC) has been carried out for a direct injection (DI), naturally aspirated diesel engine. The results have been compared with standard condition (STD) in terms of the engine performance and CO, CO 2 , NO, HC. Optimal condition has been determined as 10 CA retardation, 20% steam ratio of the fuel mass and 1.1 TC pressure (C62-S20-T1.1) in terms of the minimum NO formation. At this condition, NO, HC, CO and CO 2 reduced by 48%, 35%, 64% and 8%; the increase rates in the brake power and brake thermal efficiency are 17% and 11, respectively. The results indicated that SIM-TC-MC may be implemented into a diesel engine to control NO and to obtain higher engine performance.
Bahri Sahin - One of the best experts on this subject based on the ideXlab platform.
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effect of turbo charging and steam injection methods on the performance of a Miller Cycle diesel engine mcde
Applied Thermal Engineering, 2017Co-Authors: Guven Gonca, Bahri SahinAbstract:Abstract In this study, application of the steam injection method (SIM), Miller Cycle (MC) and turbo charging (TC) techniques into a four stroke, direct-injection diesel engine has been numerically and empirically conducted. NOx emissions have detrimental influences on the environment and living beings. They are formed at the high temperatures, thus the Diesel engines are serious NOx generation sources since they have higher compression ratios and higher combustion temperatures. The international regulations have decreased the emission limits due to environmental reasons. The Miller Cycle (MC) application and steam injection method (SIM) have been popular to abate NOx produced from the internal combustion engines (ICEs), in the recent years. However, the MC application can cause a reduction in power output. The most known technique which maximizes the engine power and abates exhaust emissions is TC. Therefore, if these three techniques are combined, the power loss can be tolerated and pollutant emissions can be minimized. While the application of the MC and SIM causes to diminish in the brake power and brake thermal efficiency of the engine up to 6.5% and 10%, the TC increases the brake power and brake thermal efficiency of the engine up to 18% and 12%. The experimental and theoretical results have been compared in terms of the torque, the specific fuel consumption (SFC), the brake power and the brake thermal efficiency. The results acquired from theoretical modeling have been validated with empirical data with less than 7% maximum error. The results showed that developed combination can increase the engine performance and the method can be easily applied to the Diesel engines.
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investigation of the effects of the steam injection method sim on the performance and emission formation of a turbocharged and Miller Cycle diesel engine mcde
Energy, 2017Co-Authors: Guven Gonca, Bahri Sahin, Adnan Parlak, Vezir Ayhan, Idris Cesur, Sakip KoksalAbstract:Abstract The steam injection method (SIM) has been widespread to abate NOx of internal combustion engines (ICEs). Another NOx reduction method known in the literature is the Miller Cycle (MC) application. However, this method causes a reduction in the power output. The most known technique which improves the engine power and decreases emissions is the turbo charging (TC). Hence, these three methods can be combined to make up for the power loss and to decrease pollutant emissions at higher rates. In this study, the combination of the SIM, TC and MC methods (SIM-TC-MC) has been carried out for a direct injection (DI), naturally aspirated diesel engine. The results have been compared with standard condition (STD) in terms of the engine performance and CO, CO 2 , NO, HC. Optimal condition has been determined as 10 CA retardation, 20% steam ratio of the fuel mass and 1.1 TC pressure (C62-S20-T1.1) in terms of the minimum NO formation. At this condition, NO, HC, CO and CO 2 reduced by 48%, 35%, 64% and 8%; the increase rates in the brake power and brake thermal efficiency are 17% and 11, respectively. The results indicated that SIM-TC-MC may be implemented into a diesel engine to control NO and to obtain higher engine performance.
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application of the Miller Cycle and turbo charging into a diesel engine to improve performance and decrease no emissions
Energy, 2015Co-Authors: Guven Gonca, Bahri Sahin, Adnan Parlak, Vezir Ayhan, Idris Cesur, Sakip KoksalAbstract:Abstract The Miller Cycle has been applied into the ICEs (internal combustion engines) to reduce NOx emissions, in the recent years. However, this method may decrease the engine power. The most common technique which improves the engine power is application of turbo charging. Thus, these two methods can be combined to make up for power loss and decrease emissions. In this study, the application of the Miller Cycle and turbo charging methods into a single cylinder, four-stroke, DI (direct injection) diesel engine has been experimentally carried out. Two different versions of the Miller Cycle, which provide 5 and 10 CA (crank angle) retarding compared to standard condition, are applied using two different camshafts. Turbo charging is applied at two different pressures, which are 1.1 and 1.2 bar, using a screw type compressor. In the results, the effective power and efficiency increased by 5.1% and 6.3%, NO, HC, CO and CO 2 decreased by 27%, 28%, 55% and 10%, respectively. The results show that combination of the proposed methods may be applied into the diesel engines to minimize NO and improve engine performance.
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comprehensive performance analyses and optimization of the irreversible thermodynamic Cycle engines tce under maximum power mp and maximum power density mpd conditions
Applied Thermal Engineering, 2015Co-Authors: Guven Gonca, Bahri Sahin, Yasin Ust, Adnan ParlakAbstract:Abstract This paper presents comprehensive performance analyses and comparisons for air-standard irreversible thermodynamic Cycle engines (TCE) based on the power output, power density, thermal efficiency, maximum dimensionless power output (MP), maximum dimensionless power density (MPD) and maximum thermal efficiency (MEF) criteria. Internal irreversibility of the Cycles occurred during the irreversible-adiabatic processes is considered by using isentropic efficiencies of compression and expansion processes. The performances of the Cycles are obtained by using engine design parameters such as isentropic temperature ratio of the compression process, pressure ratio, stroke ratio, cut-off ratio, Miller Cycle ratio, exhaust temperature ratio, Cycle temperature ratio and Cycle pressure ratio. The effects of engine design parameters on the maximum and optimal performances are investigated.
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Investigation of Heat Transfer Influences on Performance of Air-Standard Irreversible Dual-Miller Cycle
Journal of Thermophysics and Heat Transfer, 2015Co-Authors: Guven Gonca, Bahri Sahin, Yasin UstAbstract:An analysis has been performed for an irreversible dual-Miller Cycle with late inlet valve closing (LIVC), taking into consideration the influences of heat transfer loss and internal irreversibilit...
Fengrui Sun - One of the best experts on this subject based on the ideXlab platform.
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optimization of the power efficiency and ecological function for an air standard irreversible dual Miller Cycle
Frontiers in energy, 2019Co-Authors: Lingen Chen, Fengrui SunAbstract:This paper establishes an irreversible Dual-Miller Cycle (DMC) model with the heat transfer (HT) loss, friction loss (FL) and other internal irreversible losses. To analyze the effects of the cut-off ratio (ρ) and Miller Cycle ratio (rM) on the power output (P), thermal efficiency (η) and ecological function (E), obtain the optimal ρopt and optimal rMopt, and compare the performance characteristics of DMC with its simplified Cycles and with different optimization objective functions, the P, η and E of irreversible DMC are analyzed and optimized by applying the finite time thermodynamic (FTT) theory. Expressions of P, η and E are derived. The relationships among P, η, E and compression ratio (e) are obtained by numerical examples. The effects of ρ and rM on P, η, E, maximum power output (MP), maximum efficiency (MEF) and maximum ecological function (ME) are analyzed. Performance differences among the DMC, the Otto Cycle (OC), the Dual Cycle (DDC), and the Otto-Miller Cycle (OMC) are compared for fixed design parameters. Performance characteristics of irreversible DMC with the choice of P, η and E as optimization objective functions are analyzed and compared. The results show that the irreversible DMC engine can reach a twice-maximum power, a twice-maximum efficiency, and a twice-maximum ecological function, respectively. Moreover, when choosing E as the optimization objective, there is a 5.2%of improvement in η while there is a drop of only 2.7% in P compared to choosing P as the optimization objective. However, there is a 5.6% of improvement in P while there is a drop of only 1.3% in η compared to choosing as the optimization objective.
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thermodynamic optimization for an air standard irreversible dual Miller Cycle with linearly variable specific heat ratio of working fluid
International Journal of Heat and Mass Transfer, 2018Co-Authors: Lingen Chen, Fengrui SunAbstract:Abstract This paper establishes an air-standard irreversible Dual-Miller Cycle (DMC) model with the specific heat ratio (SHR) of working fluid (WF) linearly varying with its temperature. Because the specific heat (SH) of WF varies with combustion reaction in actual internal combustion engine (ICE), the SHR of WF should be a function of temperature but not a constant. In order to accurately reflect the practical characteristics of DMC engine, performance of DMC with linearly variable SHR, and with heat transfer (HT) loss, friction loss (FL) and other internal irreversible losses (IILs) is analyzed and optimized by applying finite-time thermodynamics. Analytical formulae of the power output ( P ), efficiency ( η ), entropy generation rate (EGR) and ecological function ( E ) are derived. Relationships among P , η , E and compression ratio are obtained via numerical calculations. Effects of the design parameters, Cycle temperatures and linearly variable SHR of WF on P , η and E are investigated. Performance differences among the DMC and its simplified Cycles, including Otto Cycle (OC), Dual Cycle (DDC) and Miller Cycle (OMC) are compared. Performance characteristics of the DMC with different optimization objective functions (OOFs) are analyzed. The results indicate that the maximum power output ( MP ), maximum efficiency ( MEF ) and maximum ecological function ( ME ) of the DMC are superior to those of OC, DDC and OMC, and optimizing E is the best compromise between optimizing P and optimizing η . The presented results may be helpful to optimize the performance of practical DMC engines.
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thermodynamic performance of dual Miller Cycle dmc with polytropic processes based on power output thermal efficiency and ecological function
Science China-technological Sciences, 2018Co-Authors: Jiang You, Lingen Chen, Fengrui SunAbstract:This study reports a new model of an air standard Dual-Miller Cycle (DMC) with two polytropic processes and heat transfer loss. The two reversible adiabatic processes which could not be realized in practice are replaced with two polytropic processes in order to more accurately reflect the practical working performance. The heat transfer loss is taken into account. The expressions of power output, thermal efficiency, entropy generation rate (EGR) and ecological function are addressed using finite-time thermodynamic theory. Through numerical calculations, the influences of compression ratio, cut-off ratio and polytropic exponent on the performance are thermodynamically analyzed. The model can be simplified to other Cycle models under specific conditions, which means the results have an certain universality and may be helpful in the design of practical heat engines. It is shown that the entropy generation minimization does not always lead to the best system performance.
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finite time thermodynamic modelling and analysis for an irreversible Miller Cycle
International journal of ambient energy, 2011Co-Authors: Lingen Chen, Fengrui SunAbstract:The performance of an air-standard Miller Cycle is analysed using finite-time thermodynamics. An irreversible Miller Cycle model which is more close to practice is founded. In the model, the non-linear relation between the specific heats of working fluid and its temperature, the friction loss computed according to the mean velocity of the piston, the internal irreversibility described using the compression and expansion efficiencies, and heat transfer loss are considered. The relations between the power output and the compression ratio, between the thermal efficiency and the compression ratio, and the optimal relation between power output and the efficiency of the Miller Cycle are derived by detailed numerical examples. Moreover, the effects of internal irreversibility, heat transfer loss, friction loss and pressure ratio on the Cycle performance are analysed. The power output versus compression ratio and the efficiency versus compression ratio curves of Atkinson and Otto Cycles will be maximum and minimu...
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effects of heat transfer and variable specific heats of working fluid on performance of a Miller Cycle
International journal of ambient energy, 2005Co-Authors: L Chen, Fengrui SunAbstract:SYNOPSIS The performance of an air-standard Miller Cycle with heat transfer loss and variable specific heats of working fluid is analysed by using finite-time thermodynamics. The relationships between the work output and the compression ratio, between the thermal efficiency and the compression ratio, as well as the optimal relationship between work output and the efficiency of the Cycle are derived by detailed numerical examples. Moreover, the effects of heat transfer loss and variable specific heats of working fluid on the Cycle performance are analysed. The results show that the effects of heat transfer loss and variable specific heats of working fluid on the Cycle performance are obvious, and they should be considered in practice for Cycle analysis. The results obtained herein may provide guidance for the design of practical internal combustion engines.
Yaodong Wang - One of the best experts on this subject based on the ideXlab platform.
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application of Miller Cycle with turbocharger and ethanol to reduce nox and particulates emissions from diesel engine a numerical approach with model validations
Applied Thermal Engineering, 2019Co-Authors: Yaodong Wang, Boru Jia, A P RoskillyAbstract:Abstract Because of the late intake valve closure (LIVC), Miller Cycle is kind of low temperature Cycle which means it has the ability to refrain the knocking and produce higher thermal efficiency effectively in engines. As kind of clean energy and whose combustion products are perfectly environmental-friendly, ethanol has been considering as an ideal fuel substitution for a long time. Therefore in order to reduce NOx and other particulates emissions from engine, this paper presented the technical route which applied Miller Cycle and ethanol to a turbocharged diesel engine. The simulation results shown that, Miller Cycle did bring considerable improvements on reducing NOx emission in a certain extent. Comparing with the conventional Diesel Cycle NOx emission value has been reduced in the range of 8.5–12.9% by applying Miller Cycle. After applying turbocharger into Miller Cycle engine model, NOx emission was slightly raised mostly back to the same figure as Diesel Cycle produced. Moreover, taking ethanol as fuel also produced large reduction on NOx emission comparing with the conventional engine model which taking diesel as fuel, and the range of reduction was 5.2–8.5% which could be considered as a considerable improvement. However, when turbocharger added under the same situation the figure of the range of reduction was 4.53–5.16% which is slightly lower than without turbocharger. As for particulate emission in the engine, the situation which Miller Cycle and turbocharger caused was opposite to the result of NOx emission that both Miller Cycle and turbo-charged Miller Cycle caused a larger amount of particulate emission probably due to the higher burning temperature.
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a comparison of Miller and otto Cycle natural gas engines for small scale chp applications
Applied Energy, 2009Co-Authors: R Mikalsen, Yaodong Wang, Anthony Paul RoskillyAbstract:This paper presents an investigation into the feasibility and potential advantages of a small scale Miller Cycle natural gas engine for applications such as domestic combined heat and power systems. The Miller Cycle engine is compared to a standard Otto Cycle engine using Cycle analyses and multidimensional simulation, and basic engine design implications are discussed. It is found that the Miller Cycle engine has a potential for improved fuel efficiency, but at the cost of a reduced power to weight ratio. A fuel efficiency advantage of 5-->10% compared to a standard Otto Cycle engine appears possible, however it is stated that further investigations, in particular into the topic of engine friction, are required in order to validate the findings.
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application of the Miller Cycle to reduce nox emissions from petrol engines
Applied Energy, 2008Co-Authors: Yaodong Wang, Lin Lin, A P Roskilly, Shengchuo Zeng, Jincheng Huang, Xiaodong HuangAbstract:Abstract A conceptual analysis of the mechanism of the Miller Cycle for reducing NOx emissions is presented. Two versions of selected Miller Cycle (1 and 2) were designed and realized on a Rover “K” series 16-valve twin-camshaft petrol engine. The test results showed that the application of the Miller Cycle could reduce the NOx emissions from the petrol engine. For Miller Cycle 1, the least reduction rate of NOx emission was 8% with an engine-power-loss of 1% at the engine’s full-load, compared with that of standard Otto Cycle. For Miller Cycle 2, the least reduction rate of NOx emission was 46% with an engine-power-loss of 13% at the engine’s full-load, compared with that of standard Otto Cycle.
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an analytic study of applying Miller Cycle to reduce nox emission from petrol engine
Applied Thermal Engineering, 2007Co-Authors: Yaodong Wang, Lin Lin, A P Roskilly, Shengchuo Zeng, Jincheng Huang, Xiaodong Huang, Huilan Huang, Haiyan Wei, Jing YangAbstract:Abstract An analytic investigation of applying Miller Cycle to reduce nitrogen oxides (NOx) emissions from a petrol engine is carried out. The Miller Cycle used in the investigation is a late intake valve closing version. A detailed thermodynamic analysis of the Cycle is presented. A comparison of the characters of Miller Cycle with Otto Cycle is presented. From the results of thermodynamic analyses, it can be seen that the application of Miller Cycle is able to reduce the compression pressure and temperature in the cylinder at the end of compression stroke. Therefore, it lowers down the combustion temperature and NOx formation in engine cylinder. These results in a lower exhaust temperature and less NOx emissions compared with that of Otto Cycle. The analytic results also show that Miller Cycle ratio is a main factor to influence the combustion temperature, and then the NOx emissions and the exhaust temperature. The results from the analytic study are used to analyse and to compare with the previous experimental results. An empirical formula from the previous experimental results that showed the relation of NOx emissions with the exhaust temperature at different engine speed is presented. The results from the study showed that the application of Miller Cycle may reduce NOx emissions from petrol engine.
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experimental investigation of applying Miller Cycle to reduce nox emission from diesel engine
Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2005Co-Authors: Yaodong Wang, Shengchuo Zeng, Jincheng Huang, Xiaodong Huang, Lin LinAbstract:AbstractAn experimental investigation of nitrogen oxides (NOx) emission reduction from a diesel engine using the Miller Cycle was carried out. A Lister-Petter diesel engine, type TS2, was used for the experiments. Three versions of Miller Cycles were designed and realized on a diesel engine. A series of tests were carried out on the test rig to compare the performances and emissions of the original engine (standard dual Cycle) with those of the three versions of Miller Cycles. The test results from the standard dual Cycle and from the three versions of Miller Cycles showed that applying Miller Cycle to the diesel engine could reduce the NOx emission from the diesel engine. The reduction ratios of NOx for the Miller Cycles are from 4.4 to 17.5 per cent. The best reduction effect is Miller Cycle 1 and the reduction rates of NOx are from 11.0 to 17.5 per cent.
Adnan Parlak - One of the best experts on this subject based on the ideXlab platform.
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investigation of the effects of the steam injection method sim on the performance and emission formation of a turbocharged and Miller Cycle diesel engine mcde
Energy, 2017Co-Authors: Guven Gonca, Bahri Sahin, Adnan Parlak, Vezir Ayhan, Idris Cesur, Sakip KoksalAbstract:Abstract The steam injection method (SIM) has been widespread to abate NOx of internal combustion engines (ICEs). Another NOx reduction method known in the literature is the Miller Cycle (MC) application. However, this method causes a reduction in the power output. The most known technique which improves the engine power and decreases emissions is the turbo charging (TC). Hence, these three methods can be combined to make up for the power loss and to decrease pollutant emissions at higher rates. In this study, the combination of the SIM, TC and MC methods (SIM-TC-MC) has been carried out for a direct injection (DI), naturally aspirated diesel engine. The results have been compared with standard condition (STD) in terms of the engine performance and CO, CO 2 , NO, HC. Optimal condition has been determined as 10 CA retardation, 20% steam ratio of the fuel mass and 1.1 TC pressure (C62-S20-T1.1) in terms of the minimum NO formation. At this condition, NO, HC, CO and CO 2 reduced by 48%, 35%, 64% and 8%; the increase rates in the brake power and brake thermal efficiency are 17% and 11, respectively. The results indicated that SIM-TC-MC may be implemented into a diesel engine to control NO and to obtain higher engine performance.
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application of the Miller Cycle and turbo charging into a diesel engine to improve performance and decrease no emissions
Energy, 2015Co-Authors: Guven Gonca, Bahri Sahin, Adnan Parlak, Vezir Ayhan, Idris Cesur, Sakip KoksalAbstract:Abstract The Miller Cycle has been applied into the ICEs (internal combustion engines) to reduce NOx emissions, in the recent years. However, this method may decrease the engine power. The most common technique which improves the engine power is application of turbo charging. Thus, these two methods can be combined to make up for power loss and decrease emissions. In this study, the application of the Miller Cycle and turbo charging methods into a single cylinder, four-stroke, DI (direct injection) diesel engine has been experimentally carried out. Two different versions of the Miller Cycle, which provide 5 and 10 CA (crank angle) retarding compared to standard condition, are applied using two different camshafts. Turbo charging is applied at two different pressures, which are 1.1 and 1.2 bar, using a screw type compressor. In the results, the effective power and efficiency increased by 5.1% and 6.3%, NO, HC, CO and CO 2 decreased by 27%, 28%, 55% and 10%, respectively. The results show that combination of the proposed methods may be applied into the diesel engines to minimize NO and improve engine performance.
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comprehensive performance analyses and optimization of the irreversible thermodynamic Cycle engines tce under maximum power mp and maximum power density mpd conditions
Applied Thermal Engineering, 2015Co-Authors: Guven Gonca, Bahri Sahin, Yasin Ust, Adnan ParlakAbstract:Abstract This paper presents comprehensive performance analyses and comparisons for air-standard irreversible thermodynamic Cycle engines (TCE) based on the power output, power density, thermal efficiency, maximum dimensionless power output (MP), maximum dimensionless power density (MPD) and maximum thermal efficiency (MEF) criteria. Internal irreversibility of the Cycles occurred during the irreversible-adiabatic processes is considered by using isentropic efficiencies of compression and expansion processes. The performances of the Cycles are obtained by using engine design parameters such as isentropic temperature ratio of the compression process, pressure ratio, stroke ratio, cut-off ratio, Miller Cycle ratio, exhaust temperature ratio, Cycle temperature ratio and Cycle pressure ratio. The effects of engine design parameters on the maximum and optimal performances are investigated.
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Comparison of steam injected diesel engine and Miller Cycled diesel engine by using two zone combustion model
Journal of The Energy Institute, 2015Co-Authors: Guven Gonca, Bahri Sahin, Adnan Parlak, Aykut SafaAbstract:Abstract Emissions, especially NO x , released from diesel engines must be decreased to limit values described by the regulations because emissions have many bad effects on the environment. One of the known methods for reduction NO x emissions is to apply Miller Cycle to a diesel engine. In this study, Miller Cycle is carried out by lowering the compression ratio according to the expansion ratio with closing the intake valve 30° crank angle later from the BDC (Bottom Dead Center) compared to standard diesel engine. Another method used is steam injection into diesel engine to decrease NO x emissions. And also, this method could be used to improve the performance and efficiency. Because of these positive effects, Miller Cycle and steam injection methods could be implemented into diesel engines together. In this paper, Miller Cycled diesel engine with steam injection has been modeled by using zero-dimensional two-zone combustion model. The obtained results have been compared with conventional diesel engine, Miller Cycled diesel engine and steam injected diesel engine in terms of performance and NO emissions. In the results, Miller Cycled diesel engine with steam injection is more efficient at low and medium engine speeds and has less NO emissions than conventional diesel engine, steam injected diesel engine and Miller Cycled diesel engine in all conditions.
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theoretical and experimental investigation of the Miller Cycle diesel engine in terms of performance and emission parameters
Applied Energy, 2015Co-Authors: Guven Gonca, Bahri Sahin, Adnan Parlak, Yasin Ust, Vezir Ayhan, Idris Cesur, Baris BoruAbstract:Pollutant exhaust emissions, particularly NOx, produced by diesel engines must be reduced to limit values defined by the environmental regulations as the emissions have many harmful influences on the environment. Recently, the application of the Miller Cycle into the internal combustion engines has been proposed to abate NOx emissions. In the present study, the Miller Cycle with late intake valve closing (LIVC) version is applied into a single cylinder, four-stroke, direct injection, naturally aspirated diesel engine. Three different cam shafts have been manufactured to provide 5, 10 and 15 crank angle (CA) retarding compared to original camshaft. The optimum retarding angle has been determined as 5 CA in terms of NOx reduction. The attained results have been compared with conventional diesel engine which has standard CA (0 crank angle retarding) in point of the performance and NO, HC, CO emissions. In order to provide a model validation for engine torque, brake power, brake efficiency, specific fuel consumption (SFC) and NO, the Miller Cycle diesel engine is modeled by using two-zone combustion model for 5 CA retarding at full load conditions. The simulation results have been verified with experimental data with non-considerable errors. In the experimental results, NO emissions decreased by 30% with 2.5% power loss and a remarkable change is not seen in the HC, CO emissions. The results show that the method could be easily applied into the diesel engine in order to minimize NO emissions.