Exhaust Gas Recirculation System Research Articles

Characteristics of Integrated Air Control and Low-Pressure Exhaust Gas Recirculation Valve for Diesel Engines

The purpose of this study is to investigate the characteristics of a newly introduced integrated exhaust gas recirculation (EGR) valve. Traditionally, a exhaust-pressure regulating valve is installed to increase the EGR flow rate; the method used in this study induces an increase of the EGR flow by restricting fresh intake. Unlike the two-motor two-drive system of the low-pressure (LP)-EGR system, the air control valve (ACV) and EGR valve are constructed in a linked structure. The two valves can be controlled simultaneously by a single driver, which permits reductions in volume and weight. In order to compare the existing LP-EGR system with the integrated LP-EGR system, the characteristics of the system were analyzed by a rig test and an actual engine test. It was determined that as the EGR valve opened, the EGR rate was increased and the torque was decreased under the same load condition because of the pumping resistance caused by the ACV closing.

Semi-Tensor Product of Matrices Approach to the Problem of Fault Detection for Discrete Event Systems (DESs)

This brief focuses on presenting a state-based matrix approach to the problem of fault detection for discrete event systems (DESs). Firstly, the given system is modeled as a finite state machine and converted into algebraic structure with the help of semi-tensor product of matrices. Assuming that the faults influence only the state transition and can’t recover, there are two possible constructions for the system: a normative and a faulty one. Considering the evolutionary process for the two systems, labeled correlative matrices between current state and initial state are established, respectively, which have an advantage in computer storage compared with existent methods. And then, a theorem is proposed as a criterion of detectable faults, followed with a corresponding algorithm to verify whether the faults are detectable for a given system. Finally, the approach in this brief is tested effectively for the exhaust gas recirculation system.

Analysis of the influence of dienitro on co and nox emissions in diesel public transport buses with egr and scr systems

Transport of people and goods has always been associated with the generation of some pollution, whether atmospheric, sound or visual. Managing the urban environment presents a major challenge: preserving environmental resources and also ensuring decent living conditions for the current population and for future generations. In the era of motorized and carbonized transport, vehicles are the main source of emission of atmospheric pollutants, mainly in large urban centers and important precursors of ozone. An important advance in minimizing vehicle emissions was the introduction of cleaner and additive fuels into the Brazilian market. The aim of this study was to evaluate the influence of the use of 0.15% dienitro on S50 Diesel in engines with EGR (Exhaust Gas Recirculation) and S10 Diesel in engines with SCR (Selective Catalytic Reduction) and EGR system. The tests were performed with a gas analyzer directly on the exhaust of vehicles with engine speed of 1300 rpm. Results show CO emission reductions of 72.8, 37.9, 15.7% and NOx emission reductions of 48.0, 48.5 and 31.0%, respectively for the S50 EGR, S10 SCR and S10 EGR system. This additive has a slight increase of 1 or 1.5 points in cetane number, low vaporization enthalpy (energy to vaporize) and high combustion enthalpy, ie, Dienitro increased cetane number, faciliting the start of combustion and reducing CO. On the other hand, a fuel that releases less energy during combustion consequently produces lower temperatures within the combustion chamber, ie additives with lower combustion enthalpy have lower NOx emissions.

Numerical simulation of the effect of diluents on NO<sub>x</sub> formation in methane and methyl formate fuels in counter flow diffusion flame

The increasing global demand for energy, the need to reduce green house gasses, and the depletion of fossil fuel resources have led for the need for renewable fuel sources such as biodiesel fuels. In the diesel engines, biodiesel fuels can also be used directly without comprehensive engine changes. Biodiesel relates to a diesel fuel that is based on vegetable oil or animal fat consisting of longchain of methyl, ethyl, or propyl esters. Methyl ester fuel burns more efficiently and has lower emissions of particulate matter, unburnt hydrocarbon, and carbon monoxide than fossil fuels. However, combustion of methyl ester fuel results in increased nitrogen oxides (NOx) emissions relative to fossil fuels. This study is concerned with characterizing the formation of NOx in the combustion of methyl formate under a counter diffusion flame. This was carried out in an Exhaust Gas Recirculation (EGR) system. Simulation of the process was done using Combustion Simulation Laboratory Software (COSILAB), and involved simulating the reactions of methyl formate fuel. The results obtained were compared to those of the methane/air diffusion flame, which is a well-characterized system. The extension validated the results obtained for the methyl formate/air diffusion flame. The reduction of NOx was found to be 26% and 14% in methane and methyl formate diffusion flame respectively from 0% to 29.5% of EGR. Increased EGR from 0% to 29.5% increased NOx reduction. Compared to methane/air diffusion flame, methyl formate/air diffusion flame with and without EGR had lower NOx emission. This was found to be true when examining the amount of other metrics viz. temperature, H, OH and N radicals associated with NOx. This showed that EGR system have an effect on NOx formation.

Setup and Control of a Two-Stage Turbocharged Gasoline Engine with Low Pressure EGR in a Prototype Vehicle

Abstract In order to cope with the strict emission standards for vehicles with internal combustion engines, new and innovative air path concepts with e.g. combined turbocharging and exhaust gas recirculation (EGR) are in the focus of research and the industry. Intensive simulative investigations of different concepts usually build the basis for determining which alternatives are promising and should be pursued. The concepts need to be tested and validated under conditions being as realistic as possible. Therefore, engines with the desired air and EGR path layouts are set up on test benches and tested under laboratory conditions. With the real-driving emission (RDE) legislation, it is crucial to test new air path concepts also during real driving on the road. Thus, demonstrator vehicles need to be developed. This paper presents the setup of a prototype demonstrator vehicle with an innovative air path concept for gasoline engines. The engine is equipped with a two stage sequential turbocharging system and a low pressure EGR path. As turbocharged gasoline engines have an increased specific power output, engines can be downsized for increased efficiencies. By using an EGR system, the increased in-cylinder temperatures of turbocharged engines during high load operation can be lowered, reducing the knock tendency and the exhaust gas temperature. The more and more complex air path concepts pose great demands on the process control which needs to handle nonlinear, cross-coupled multiple-input and multiple-output systems with dead times during transient operation. The setup of the vehicle with actuators, sensors and measurement technology as well as a possible control concept will be presented in detail.

Effect of biosolar fuels and S. Marginatum algae biofuel on equivalence ratio in diesel engine with EGR

One type of motor vehicle engine that is very suitable for transportation and heavy equipment vehicles is a diesel engine, because high combustion efficiency, reliability, fuel flexibility, and low fuel consumption make diesel widely used in several countries. A mixture of S. Marginatum algae biodiesel and bio solar fuel is used as an alternative fuel. This test is carried out by using variations in the percentage of the load, with variations of pure diesel fuel (D100) and a mixture of bio solar fuels, and algae biodiesel at t 1500 rpm. In this context, the purpose of this study was to obtain its performance curves from a diesel engine of the brand, using as fuel mixtures diesel oil, bio solar fuel, and S. Marginatum algae biodiesel, in the proportions B20, B20 + 10%, B20 + 15%, and B20 + 20%, the power take-off dynamometer test. The results showed that engine performance of equivalence ratio an increase with other models of the same used in the region, showing the best engine output in the region bio solar fuel mixtures with the Hot EGR (Exhaust Gas Recirculation) system.

Development of an exhaust gas recirculation system for diesel engines

This paper presents the author's method of developing an original solution to improve the efficiency of the exhaust gas recirculation system for diesel engines based on the TRIZ-FSA system with obtaining a patent for the method and device.

EGR modeling and fuzzy evaluation of Low-Speed Two-Stroke marine diesel engines

Exhaust gas recirculation (EGR) can be widely used to reduce the oxynitride (NOx) pollution in Low-Speed Two-Stroke Marine Diesel Engines. In this paper, two EGR systems (HP EGR11HP EGR: high pressure EGR. and LP EGR22LP EGR: low pressure EGR.) were investigated in terms of the influence of different rates on the brake specific fuel consumption (BSFC) and the NOx emissions. As for this simulation, the exhaust gas cleaning water treatment was not concluded. Besides, Miller Cycle was used to determine the influence of its valve timing on BSFC and NOx emissions. The combination of Miller Cycle and HP EGR system decreased the NOx emissions, which could meet the IMO33IMO: international maritime organization. Tier III standard, 3.4 g/kWh. Moreover, the influence of the EGR cooling temperature was discussed. Finally, a fuzzy comprehensive evaluation model was developed to evaluate the two EGR systems. The results showed that when the HP EGR system and the LP EGR system were all operating at a maximum EGR rate, LP EGR system showed more advantages.

Study of the effect of the Dienitro additive on the NOx and CO emissions in buses of collective transport to Diesel S-50 EGR and S-10 with SCR and EGR systems

PurposeTransport of people and goods has always been associated with the generation of some form of pollution, whether atmospheric, sound or visual. Managing the urban environment presents a major challenge: preserving environmental resources and also ensuring decent living conditions for the current population and for future generations. In the era of motorized and carbonized transport, vehicles are the main source of emission of atmospheric pollutants, mainly in large urban centers and important precursors of ozone. An important advance in minimizing vehicle emissions was the introduction of cleaner and additive fuels into the Brazilian market. The purpose of this paper is to study the effect of the Dienitro additive on the NOx and CO emissions in buses of collective transport, Diesel S-50 exhaust gas recirculation (EGR) and S-10 with selective catalytic reduction (SCR) and EGR systems. Measurements of CO and NOx gas emissions were carried out using a gas analyzer in S50 and S10 diesel buses with an EGR and SCR systems from a company operating in the collective transport of Biguaçu.Design/methodology/approachIn this study, 20 measurements were performed without additives and 20 measurements with additivation in each bus, making it possible to calculate the average emission rate of CO and NOx, pollutant gases with toxic effect.FindingsThe usage of Dienitro additive in diesel engines resulted in a significant reduction in the emission of polluting gases, carbon monoxide (CO) and nitrogen oxide (NOx), thus being efficient in reducing the emissions of these gases.Originality/valueThe Dienitro additive was first tested on diesel engines by public transport buses, and there is great potential for reducing the emission of toxic gases.

Performance Optimization of a Diesel Engine with a Two-Stage Turbocharging System and Dual-Loop EGR Using Multi-Objective Pareto Optimization Based on Diesel Cycle Simulation

The effects of an electric supercharger (eS) and a dual-loop exhaust gas recirculation (EGR) system on a passenger car’s diesel engine’s emissions and fuel efficiency under various worldwide harmonized light-duty vehicles test procedure (WLTP) reference operation points were investigated using a one-dimensional engine cycle simulation, called GT-Power. After heavy EGR application, the in-cylinder pressure and temperature declined due to a dilution effect. As eS power and rpm increased, the brake-specific fuel consumption (BSFC) decreased because the effects of the air flow rate increased. However, it was unavoidable that nitrogen oxide (NOx) emissions also increased due to the higher in-cylinder pressure and temperature. To induce more EGR to the intake system, a dual-loop EGR system was applied with eS at different low-pressure EGR (LP-EGR) fractions (0, 0.25, 0.5, 0.75, and 1.0). Under these conditions, a design of experiment (DoE) procedure was carried out and response surface plots of the BSFC and brake-specific NOx (BSNOx) were prepared. A multi-objective Pareto optimization method was used to improve the trade-off in results between the BSFC and BSNOx. Through optimization, optimal Pareto fronts were obtained, which suggested design parameters for eS power and rpm to control the engine under various LP fraction conditions.

Experimental Test of the Effect Wet Ethanol on Decreasing Emissions Exhaust in EFI Gasoline Engine with EGR System

The increase in the number of vehicles results in increased fuel consumption and air pollution. This also affects the more depletion of fossil fuel availability. An increasing number of these vehicles contribute to air pollution in urban areas. Hazardous substances such as NOx (Nitrogen Oxide), CO (Carbon Monoxide), and HC (Hydrocarbon) are harmful to health. In order to reduce the emissions of CO and HC, wet ethanol is one of the solutions to overcome these problems. Besides ethanol can be obtained from materials that are renewable. In fact, wet ethanol has a value of higher octane and higher oxygen content than gasoline. Blending both the fuel is expected to reduce air pollution. The purpose of this research is to obtain the best premium and wet ethanol percentage for lowering emissions of CO and HC. The fuel used is gasoline (88 octane number) and the wet ethanol (109 octane number). The percentage of wet ethanol blended into the fuel is in the range of 5% to 15%. Experiments conducted an engine speed of 2500 to 4000 rpm with an interval of 500 rpm. This study investigates the effects of wet ethanol and premium blends and the use of EGR (Exhaust Gas Recirculation) against exhaust emissions on a gasoline engine with EFI systems (Electronic Fuel Injection). From the results of this study is found that the exhaust gas temperature increases in the increase of engine speed. The addition of EGR reduces the exhaust gas temperature. The increase in BSFC (brake specific fuel consumption) without the largest EGR at we15 is 3.36% at 0.38 kg/kw. Hour, while the decrease in BSFC with the largest EGR at we5 is 17.61% at 0.30 kg/kw. Hour. Wet ethanol and gasoline blends cause a decrease in emissions of CO and HC. With a 15% wet ethanol blend, CO and HC emissions can be reduced to 60.23% and 44.30%, respectively. However, adding 15% wet ethanol into gasoline fuel increases 34.66% of CO2.

Retrofitting and re-powering as a control strategies for curtailment of exposure of underground miners to diesel aerosols.

A study was conducted to examine the potential of diesel emissions control strategies based on retrofitting existing power packages with exhaust aftertreatment devices and repowering with advanced power packages. The retrofit systems, a diesel oxidation catalyst (DOC) and diesel particulate filter (DPF), were evaluated individually using a US EPA tier 2 (ter 2) engine operated under four steady-state conditions and one transient cycle. The DOC effectively curtailed emissions of CO, and to some extent organic carbon (OC), elemental carbon (EC), and aerosol number concentration. The DPF system offered substantially higher reductions in OC and EC mass and aerosol number concentrations. Both, the DOC and DPF achieved reductions in the aforementioned emissions without adversely affecting emissions of NO2 and nano-sized aerosols. The strategy of repowering with an advanced system was examined using a US EPA tier 4 final (tier 4f) engine equipped with a cooled exhaust gas recirculation system and diesel exhaust fluid-based selective catalytic reduction system, but not with a DPF system. The tier 4f engine contributed substantially less than the tier 2 engine to the EC and OC mass, aerosol number, and CO, NO, and NO2 concentrations. The tier 4f engine was very effective in reducing aerosol mass, NO, and NO2 concentrations, but it was not equally effective in reducing aerosol number concentrations. The implementation of viable exhaust after treatment systems and advanced diesel power packages could be instrumental to the underground mining industry to secure a clean, economical, and dependable source of power for mobile equipment.

Nonlinear observer-based exhaust manifold pressure estimation and fault detection for gasoline engines with exhaust gas recirculation

This article presents a nonlinear observer-based method to estimate the exhaust manifold pressure for the gasoline engines equipped with an exhaust gas recirculation system. A dynamic model is designed to estimate the exhaust manifold pressure, which includes both the intake manifold and exhaust manifold dynamics focusing on gas mass flows. Based on the developed model, a nonlinear exhaust manifold pressure observer is proposed to replace the exhaust manifold pressure sensor, and the global convergence is analyzed by a constructed Lyapunov function and the physical meaning of the time-varying parameters. The experimental validations show that the observer-based exhaust manifold pressure estimator is able to converge to the real value at arbitrary initial value and estimates the exhaust manifold pressure accurately during both the steady-state and transient conditions. Finally, the proposed exhaust manifold pressure observer is applied into the fault detection problem for the exhaust gas recirculation system. The experimental validations show that the observer is able to be used to estimate the exhaust gas recirculation ratio and as an extra signal to assist to detect the faults of the exhaust gas recirculation system accurately.

Intelligent Control Strategy for Transient Response of a Variable Geometry Turbocharger System Based on Deep Reinforcement Learning

Deep reinforcement learning (DRL) is an area of machine learning that combines a deep learning approach and reinforcement learning (RL). However, there seem to be few studies that analyze the latest DRL algorithms on real-world powertrain control problems. Meanwhile, the boost control of a variable geometry turbocharger (VGT)-equipped diesel engine is difficult mainly due to its strong coupling with an exhaust gas recirculation (EGR) system and large lag, resulting from time delay and hysteresis between the input and output dynamics of the engine’s gas exchange system. In this context, one of the latest model-free DRL algorithms, the deep deterministic policy gradient (DDPG) algorithm, was built in this paper to develop and finally form a strategy to track the target boost pressure under transient driving cycles. Using a fine-tuned proportion integration differentiation (PID) controller as a benchmark, the results show that the control performance based on the proposed DDPG algorithm can achieve a good transient control performance from scratch by autonomously learning the interaction with the environment, without relying on model supervision or complete environment models. In addition, the proposed strategy is able to adapt to the changing environment and hardware aging over time by adaptively tuning the algorithm in a self-learning manner on-line, making it attractive to real plant control problems whose system consistency may not be strictly guaranteed and whose environment may change over time.

ЗМЕНШЕННЯ ВИКИДІВ СУДНОВОГО ДИЗЕЛЯ УТИЛІЗАЦІЄЮ ТЕПЛОТИ РЕЦИРКУЛЯЦІЙНИХ ГАЗІВ ЕЖЕКТОРНОЮ ХОЛОДИЛЬНОЮ МАШИНОЮ

The problem of air basin pollution of the World Ocean with harmful emissions from the exhaust gases of marine diesel engines is primarily associated with the creation of highly efficient technologies for the neutralization of nitrogen oxides NOx on exhaust gases from a diesel engine. Emissions of harmful substances from the combustion of marine fuels are limited by international atmospheric protection programs and the requirements of the International Maritime Organization (IMO). The requirements relate to almost all groups of harmful emissions in marine engines and the more stringent of them are primarily related to nitrogen oxides NOx and sulfur oxides SOx. To reduce harmful emissions from exhaust gases into the environment, scientists and world engine leaders use and suggest various methods for reducing the content of harmful substances in exhaust gases. The implementation of new standards in the areas of further improvement of the working process, the use of alternative fuels, fuel, and air additives, as well as selective catalytic reduction systems do not preclude further development of scientific research in the field of exhaust gas cleaning. One of the promising ways in environmentalizing marine internal combustion engines is the neutralization of harmful substances in exhaust gases through particular gas recirculation (EGR-technology). However, the use of such techniques conflicts with the engine's energy efficiency. In the work presented, the scheme-design solution of the exhaust gas recirculation system with using the heat of recirculation gases by an ejector refrigeration machine for cooling the air at the intake of ship's main engine is proposed. The effect of using the heat of recirculation gases for cooling the air at the intake of the engine is analyzed taking into account the changing climatic conditions for a particular vessel's route line. It is shown that the use of an ejector refrigeration machine reduces the air temperature at the entrance of the main engine by 5…15 ° С, which reduces the specific fuel consumption. This reduces emissions of harmful substances when the engine is running with recirculation of gases.

ЗАСТОСУВАННЯ ГАЗОДИНАМІЧНОГО ОХОЛОДЖЕННЯ В СИСТЕМАХ РЕЦИРКУЛЯЦІЇ ВІДХІДНИХ ГАЗІВ СУДНОВИХ ДИЗЕЛІВ

There are many ways and methods to reduce exhaust gases emissions on modern ships. One of the most effective ways to reduce NOx and SOx emissions is to use of exhaust gas recirculation (EGR technology). The EGR system disadvantage is an increase in back pressure through additional pressure losses in the scrubber and heat ex-changer, which entails an engine fuel efficiency deterioration. Creating a reliable and efficient heat exchanger for cooling recirculation gases is a complex task due to deposits and pollution emitted by these gases. In the pre-sent work, the jet apparatus effectiveness named aerothermopressor is analyzed in the scheme with exhaust gases recirculation of the ship low-speed two-stroke engine. Aerothermopressor is a two-phase jet for contact disperse cooling, in which by increasing the heat from the gas stream the gas pressure and cooling are increased. The calculation of the characteristics of the engine was carried out, both in nominal, and in operating modes and in all possible range of partial loads. The installation of the aerothermopressor before the scrubber is pro-posed, which allows reducing engine thermal load. Increasing the pressure in the aerothermopressor by 0.2-0.4 ∙ 105 Pa (6-12 %) allows reducing the back pressure in the gas exhaust system and thus reducing the load on the exhaust gas recirculation fan and when the engine load is higher than 75% in the cold zone, the fan is not need-ed, which additionally allows to reduce the specific fuel consumption. The parameters of the exhaust gases that are going to be recirculated and the processes of their gas-dynamic cooling in the aerothermopressor are based on the developed technique and program using the thermodynamic and gas dynamics equations. The proposed scheme-design solution allows at a high environmental friendliness of the existing exhaust gas recirculation sys-tem to provide a certain reduction in specific fuel consumption. It was determined that the engine specific fuel consumption has been decreasing when the aerothermopressor is used to Dge = 2.5-3.0 g/(kW·h) (1.5-1.7%).

Establishment of lower exhaust emissions by using EGR coupled low heat loss diesel engine with fuel blends of microalgae biodiesel-oxygenated additive DEE-antioxidant DPPD

The aims of the research work are: Achieving maximum reduction in the exhaust emissions of the diesel engine and investigate the potentiality of a higher ratio of biodiesel blended with suitable additives as an alternative for diesel fuel. Herein, a coated engine (CE) was produced by the application of bond coating NiCrAlY on the cylinder head and liner substrate, further it was coated with 8 mol.% Yttria-stabilized zirconia (8-YSZ) ceramic. The YSZ restrict the in-cylinder combustion heat loss to the coolant and combustion chamber components due to its low thermal conductivity. The CE was coupled with an exhaust gas recirculation (EGR) system at an optimal constant rate of 10% by vol. to reduce the formation of NOx emissions. Fuel blends with different combinations of microalgae (Chlorella protothecoides) oil-based biodiesel (MB) and additives diethyl ether (DEE), amine antioxidant N, N′-diphenyl-1,4-phenylenediamine (DPPD) were synthesized and tested. The experiment was carried out by scrutinizing the emissions and performance of CE fuelled by blends with a comparison to the uncoated engine (UE) with diesel at different load conditions. The results had shown that the additives enhanced the oxidation stability, cetane number while decreasing the viscosity of the biodiesel. The EGR coupled CE displayed improvement in all the investigated parameters with optimum of particulate emissions by 45.5%, un-burnt hydrocarbons by 51%, NOx by 18.5, CO emissions by 47%, peak brake thermal efficiency by about 6% and brake specific fuel consumption by 8.5% found for the blend MB85DEE15DPPD 1000 ppm (microalgae biodiesel 85%+ diethyl ether 15%+DPPD 1000 ppm) at 80% load. This work made a substantial approach to an economic contribution by simultaneously addressing global issues like air-pollution and fossil fuel crisis.

Multi-objective NSGA-II optimization of a compression ignition engine parameters using biodiesel fuel and exhaust gas recirculation

In this study an exhaust gas recirculation system was developed for a small single cylinder 4-stroke engine. Then the mathematical models to correlate responses as the engine emissions and performance characteristics to the factors, include engine load, engine speed, EGR rate and biodiesel fuel percent, were developed. Finally, by using the developed models and NSGA-II (Non-dominated Sorting Genetic Algorithm II) method, the factors were optimized. The highest decrease in NOx emissions while using the biodiesel and EGR is 63.76% with B10 fuel blend (10% biodiesel fuel and 90% diesel fuel blend by volume) and 30% EGR rate. The highest reduction in HC emission levels while using EGR and biodiesel simultaneously, has been 54.05%. The adjusted R2 of the proposed model for the CO, HC, NOx, Power, BSFC and smoke were 0.94, 0.91, 0.88, 0.95, 0.89 and 0.94, respectively. Results of the optimization of the engine factors with NSGA-II method has been satisfactory and the pareto front for different test conditions was proposed. The outcomes of the study revealed that the optimization should be taken into account in the development of the new policy for using of the biofuel in the internal combustion engines.

EFEK METANOL KADAR RENDAH TERHADAP TORSI MESIN DIESEL DENGAN SISTEM HOT EGR

One type of motorized vehicle that is very suitable for transportation and heavy equipment vehicles is diesel engines, because of its high combustion efficiency, reliability, fuel flexibility, and low fuel consumption make diesel widely used in several countries. Lowgrade methanol mixtures and jatropha are used as alternative fuels. This study aims to study the effect of low purity methanol mixture and jatropha on torque in Isuzu 4JB1 diesel engine direct injection with Hot EGR (Exhaust Gas Recirculation) system using a mixture of biodiesel fuel, low grade methanol and jatropha. The low purity methanol used has a water content of 24.88% based on volume. The ratio of biodiesel, methanol and jatropha mixture used is D85LPM5J10, D80LPM10J10, D75LPM15J10, D75LPM5J20, D70LPM10J20, D65LPM15J20, D65LPM5J30, D60LPM10J30 and D55LPM15J30. EGR openings varied from 0%, 25%, 50%, 75% and 100%. Testing is carried out at a constant rotation of 2000 rpm and given a load of 25%, 50%, 75% and 100%. This study uses dynamite Land & Sea dynamometer. The experimental results show that the EGR Effect can increase the torque value. Torque values tend to decrease when using a mixture of fuels compared to D100. At low loads (25%) there is an increase in the Torsi value for the fuel mixture D85LPM5J10, D80LPM10J10, D70LPM10J20 and D55LPM15J30 of 12.03%, 7.50%, 5.01%, and 5.97%.Keywords: Metanol, Torsi, Mesin, Diesel, EGR

Effects of torsional vibration of a propulsion shafting system and energy efficiency design index from a system combining exhaust gas recirculation and turbocharger cut out

Recently constructed vessels are equipped with super long stroke engines to accommodate stiffer environmental regulations and to reduce fuel consumption. This is a way to reduce fuel consumption in main engines for propulsion by improving propeller efficiency and thermodynamic efficiency of the engine. However, ships intended to accommodate nitrogen oxides regulations must satisfy the Tier III regulation prescribed by the International Maritime Organization. For this purpose, the vessel should apply additional nitrogen-oxide reduction facilities. When an exhaust gas recirculation (hereafter EGR) system is applied for the exhaust gas reduction, not only is the fuel consumption increased according to the amount of EGR, but the vibration excitation force tends to increase as well. In addition, there is a limit to the engine control technology that can be applied to optimize fuel consumption under partial load, even if the ship travels in areas other than NOx emission control areas, the fuel consumption of the engine is high. Therefore, it is necessary to change the design of the ship so that fuel can be saved even in areas other than NOx emission control areas by applying the turbocharger cut out (hereafter TCCO) method. In this paper, the performance and dynamic characteristics of a marine diesel engine were compared and reviewed when applying a combined system of EGR and TCCO. Also examined were effects on the torsional vibration of a corresponding propulsion shafting system and the energy efficiency design index (hereafter EEDI) according to each operating condition of the engine applied with this system.