A method of turbocharger design optimization for a diesel engine with exhaust gas recirculation

Author(s):  
Syed Ammad ud Din ◽  
Weilin Zhuge ◽  
Panpan Song ◽  
Yangjun Zhang

Downsizing a diesel engine using turbocharger and coupling it with exhaust gas recirculation is the recent trend to improve engine performance and emission control. For diesel engines, it is important to match a turbocharger that meets both the low-speed torque and high-speed power requirements. This article presents a method of turbocharger design optimization for a turbocharged diesel engine equipped with exhaust gas recirculation, on the basis of parametric study of turbocharger geometry. Turbocharger through-flow model along with one-dimensional engine model is used to study the effect of key geometric parameters of the compressor and turbine on engine brake torque, brake-specific fuel consumption, air flowrate and cylinder peak temperature. For compressor, the research emphasizes on impeller inlet relative diameter, inlet blade tip angle, impeller exit blade angle and exit blade height, while for turbine parameters such as volute throat area, inlet blade height, inlet diameter, outlet diameter and rotor exit blade angle are taken into account. Results show that in case of compressor, engine performance is sensitive to the inlet relative diameter, inlet blade angle and exit blade angle. In case of turbine, volute throat area, inlet blade height and inlet diameter have vital effect on engine performance. On the basis of results, an optimized turbocharger design is developed. Comparison shows prominent improvement in turbocharger maps and engine performance. Compressor maximum efficiency and pressure ratio are increased from 73% to 77% and 3.166 to 3.305, respectively. Most importantly, the area of compressor maximum efficiency zone is increased considerably. Also turbine efficiency is increased from 71.42% to 76.94%. As a result, engine torque and air flowrate are increased up to 5.26% and 8.31%, respectively, while brake-specific fuel consumption and cylinder peak temperature are decreased up to 5.00% and 4.31%, respectively.

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5021
Author(s):  
Sokratis Stoumpos ◽  
Gerasimos Theotokatos

Dual fuel engines constitute a viable solution for enhancing the environmental sustainability of the shipping operations. Although these engines comply with the Tier III NOx emissions regulations when operating at the gas mode, additional measures are required to ensure such compliance at the diesel mode. Hence, this study aimed to optimise the settings of a marine four-stroke dual fuel (DF) engine equipped with exhaust gas recirculation (EGR) and air bypass (ABP) systems by employing simulation and optimisation techniques, so that the engine when operating at the diesel mode complies with the ‘Tier III’ requirements. A previous version of the engine thermodynamic model was extended to accommodate the EGR and ABP systems modelling. Subsequently, a combination of optimisation techniques including multiobjective genetic algorithms (MOGA) and design of experiments (DoE) parametric runs was employed to identify both the engine and the EGR/ABP systems settings with the objective to minimise the engine brake specific fuel consumption and reduce the NOx emissions below the Tier III limit. The derived simulation results were employed to analyse the EGR system involved interactions and their effects on the engine performance and emissions trade-offs. A sensitivity analysis was performed to reveal the interactions between considered engine settings and quantify their impact on the engine performance parameters. The derived results indicate that EGR rates up to 35% are required, so that the investigated engine with EGR and ABP systems, when operating at the diesel mode, achieves compliance with the ‘Tier III’ NOx emissions, whereas the associated engine brake specific fuel consumption penalty is up to 8.7%. This study demonstrates that the combination of EGR and ABP systems can constitute a functional solution for achieving compliance with the stringent regulatory requirements and provides a better understating of the underlined phenomena and interactions of the engine subsystems parameters variations for the investigated engine equipped with EGR and ABP systems.


2020 ◽  
Vol 19 (4) ◽  
pp. 305-310
Author(s):  
G. M. Kuharonak ◽  
D. V. Kapskiy ◽  
V. I. Berezun

The purpose of this work is to consider the requirements for emissions of harmful substances of diesel engines by selecting design and adjustment parameters that determine the organization of the workflow, and the exhaust gas cleaning system, taking into account the reduction of fuel consumption. Design elements and geometric characteristics of structures for a turbocharged diesel engine of Д-245 series produced by JSC HMC Minsk Motor Plant (4ЧН11/12.5) with a capacity of 90 kW equipped with an electronically controlled battery fuel injection have been developed: exhaust gas recirculation along the high pressure circuit, shape and dimensions of the combustion chamber, the number and angular arrangement of the nozzle openings in a nozzle atomizer, and inlet channels of the cylinder head. Methods for organizing a workflow are proposed that take into account the shape of the indicator diagrams and affect the emissions of nitrogen oxides and dispersed particles differently. Their implementation allows us to determine the boundary ranges of changes in the control parameters of the fuel supply and exhaust gas recirculation systems when determining the area of minimizing the specific effective fuel consumption and the range of studies for the environmental performance of a diesel engine. The paper presents results of the study on the ways to meet  the requirements for emissions of harmful substances, obtained by considering options for the organization of working processes, taking into account the reduction in specific effective fuel consumption, changes in the average temperature of the exhaust gases and diesel equipment. To evaluate these methods, the following indicators have been identified: changes in specific fuel consumption and average temperature of the toxicity cycle relative to the base cycle, the necessary degree of conversion of the purification system for dispersed particles and NOx. Recommendations are given on choosing a diesel engine to meet Stage 4 emission standards for nitrogen oxides and dispersed particles.


2017 ◽  
Vol 110 ◽  
pp. 26-31 ◽  
Author(s):  
Mohd Hafizil Mat Yasin ◽  
Rizalman Mamat ◽  
Ahmad Fitri Yusop ◽  
Daing Mohamad Nafiz Daing Idris ◽  
Talal Yusaf ◽  
...  

Author(s):  
Y J Qian ◽  
C J Zuo ◽  
J Tan ◽  
H M Xu

This article presents the potential of improving engine performance and pollutant emissions of a ZS195 Diesel engine by exhaust gas recirculation (EGR) and intake hydrogen enrichment. The effect of EGR level and hydrogen addition on the engine performance and pollutant emissions has been investigated through detailed experiments at rated speed. The experimental results have shown that when EGR level is constant, the peak pressure and maximum rate of pressure rise increase with the increase of hydrogen addition. The intake hydrogen enrichment can reduce HC, CO, and soot level and increase NOX emission, but EGR technique can offset this effect. The combustion speed and thermal efficiency increase with the increase of hydrogen addition when EGR technique has been adopted.


REAKTOR ◽  
2017 ◽  
Vol 16 (3) ◽  
pp. 116
Author(s):  
S Syaiful ◽  
S Sobri

Diesel engines have been widely used as a mode of public transport and private vehicles because of several advantages compared to gasoline engines including greater power, fuel economy, high reliability and durability of the engine and lower CO emissions. However, diesel engines release more NOx and soot emissions into the atmosphere. This is a serious problem with the strict regulations regarding exhaust emissions. Besides problems of depletion of fossil fuel reserves require various parties to seek alternative fuels derived diesel fuel. Therefore, this work is intended to reduce soot emissions by adding LPM (low purity methanol) or wet methanol and HPM (high purity methanol) into a mixture of jatropha and diesel fuels. From this research, it is also desirable to observe the effect of methanol additive to the specific fuel consumption. Experiment method was conducted to obtain the correlation between the percentage of methanol to a brake specific fuel consumption (BSFC) and soot emissions. Methanol (LPM and HPM) was varied in the range of 5 to 15% by volume. Jatropha is in the range of 10% to 30%. The rate of EGR (exhaust gas recirculation) expressed by OEV (opening EGR valve) was varied at the opening of 0 to 100%. Engine load was varied from 25 to 100% at intervals of 25%. The engine speed was kept constant of 2000 rpm. The results show that the use of fuel mixture increases evenly BSFC of 5.2% and soot emissions of 65%. Keywords: LPM and HPM, BSFC, soot emissions, jatropha, cold EGR and diesel engine  Abstrak Mesin diesel telah banyak digunakan sebagai moda transportasi umum dan kendaraan pribadi oleh karena beberapa kelebihannya dibandingkan dengan mesin bensin diantaranya daya yang lebih besar, hemat bahan bakar, kehandalan dan ketahanan mesin yang tinggi (high realibility and durability), dan emisi CO yang lebih rendah. Akan tetapi mesin diesel melepaskan lebih banyak emisi NOx dan jelaga ke atmosfir. Hal ini menjadi permasalahan serius dengan semakin ketatnya regulasi menyangkut emisi gas buang. Selain itu permasalahan menipisnya cadangan bahan bakar fosil menuntut berbagai pihak untuk mencari bahan bakar alternatif pengganti solar. Oleh karena itu, penelitian ini bermaksud untuk mereduksi emisi jelaga dengan menambahkan LPM (low purity methanol) atau wet methanol dan HPM (high purity methanol)kedalam campuran bahan bakar jatropha dan solar. Dari penelitian ini juga diinginkan untuk mengamati pengaruh aditif metanol terhadap konsumsi bahan bakar spesifik. Metode eksperimen dilakukan untuk mendapatkan keterkaitan antara prosentase metanol terhadap brake specific fuel consumption (BSFC)dan emisi jelaga. Metanol (LPM dan HPM) divariasikan pada rentang 5% sampai 15%. Jatropha adalah pada rentang 10% sampai 30%. Laju EGR (exhaust gas recirculation) yang dinyatakan oleh OEV (opening EGR valve) divariasikan pada bukaan 0% sampai 100%. Beban mesin divariasikan dari 25% sampai 100% dengan interval 25%. Putaran mesin dipertahankan konstan 2000 rpm. Hasil-hasil penelitian menunjukkan bahwa penggunaan bahan bakar campuran rata-rata meningkatkan BSFC 5,2% dan menurunkan emisi jelaga sampai 65%.


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