EGR Technique Research Articles

Effects of exhaust gas recirculation on diesel engine using hybrid biodiesel

The primary aim of this study is to alternate between conventional fossil fuels and reduce the emissions of greenhouse gases and sulfur dioxide from diesel engines. In the current study, to mitigate NOx emissions, the exhaust gas recirculation (EGR) technique was implemented utilizing hybrid alternate biodiesel at three varying proportions of 5%, 10%, and 15% at an optimum compression ratio of 20:1. The findings demonstrate that for hybrid alternative biodiesel at a compression ratio of 20:1 and fully loaded, the brake thermal efficiency (BTHE) is 31.8% with 10% EGR. With 15% EGR, the peak pressure for the hybrid biodiesel is lower than it would be without EGR by around 2.28%. When EGR is increased, the ignition delay and NOx emissions are reduced slightly. With only an increase in EGR rates of up to 10%, brake-specific fuel consumption (BSFC) values were reduced efficiently. The hybrid biodiesel with 10% EGR reduces exhaust gas temperature to 341?C.

A Comparative Study between Hot EGR and CI Engine Using Mahua Oil Mixtures as Fuels

An investigation of CI engine using mahua oil methyl esters and its mixtures with hot EGR (HEGR) techniques has been investigated and presented. An optimum injection timing of 20 deg bTDC and injection pressure of 250 bar and is fixed and conducted the study. The emissions of mahua biodiesel and its mixtures with CI engine with hot EGR technique. The experimental test results are compared between Hot EGR and CI Engine (without adopting EGR technique). The same is compared and presented. For various test fuel samples, an increasing trend is noticed for various emissions for Hot EGR. The HEGR gave lower emissions at various loads. The neat biodiesel with Hot EGR (B100) gave greatest % reduction in NOx of 10.81% and 5.41% at minimum and maximum load. In general, EGR provides little bit higher NOx due to soot.

Impact of exhaust gas recirculation and split injection strategy combustion behavior on premixed charge compression ignition engine fuelled with moringa oleifera methyl ester

Influence of split injection strategy of moringa oleifera methyl ester and its blends with exhaust gas recirculation on diesel engine combustion, performance and emission characteristics using common rail direct injection (CRDI) system were investigated in this work. In split injection strategy, the pilot (PIT) and main injection timings (MIT) were fixed between 35 °CA – 40 °CA bTDC and 15 °CA –25 °CA bTDC, respectively. The minimum and maximum nozzle opening pressure were fixed as 300 and 600 bar with an interval of 100 bar. In addition, 10% to 30% of EGR flow rate was introduced with an interval of 5%. Experimental results reveal that B100-10%-90% has achieved maximum brake thermal efficiency of 35% at PIT of 35 °CA bTDC, MIT of 25 °CA and NOP of 300 bar. Usage of pure moringa oleifera biodiesel in diesel engine under split injection strategy results in better combustion characteristics due to premixed and diffused heat release rate phasing with lower peak cylinder pressure. In addition, B100-10%-90% emits maximum nitric oxide emission of 1520 ppm, and least unburned hydrocarbon and carbon monoxide emission of 4 ppm and 0.01% vol respectively at 600 bar NOP with PIT of 35 °CA and MIT of 25 °CA. Moreover, Nitric oxide emission is reduced as the EGR rate gradually increases from 10% to 30%; on the other side, brake specific fuel consumption, carbon monoxide, and unburned hydrocarbon emissions are marginally increased. This research depicts that split injection strategy and EGR technique have simultaneously lowered the nitric oxide and smoke emissions while improving engine performance.

Analysis of optimising injection parameters and EGR for DICI engine performance powered by lemongrass oil using Box–Behnken (RSM) modelling

The current study focuses on determining the optimum injection parameters and EGR using the RSM technique’s Box–Behnken approach. Neat lemongrass oil (LGO)/diesel blend is used in direct injection diesel engines. Based on the comprehensive analysis, optimisation was performed to establish the optimal injection pressure, timing, and EGR. The injection parameters must be optimised and EGR technique to decrease NOx emission and maximise BTE without much effect on BSFC and other emissions. The actual experimentation outcomes and the R 2 values that reveal the correlation between the results of optimisations and actual tests were found in good agreement. The optimum injection pressure, timing and EGR were found as 250 bar, 26°bTDC and 8.12% respectively. From the investigational results, the BTE was improved by 6.61% while BSFC decreased by 3.01% than normal diesel fuel operation. Furthermore, CO, HC, NOx and Smoke decreased by 23.65%, 21.20%, 32.85% and 27.73% respectively compared to diesel.

Performance study on the C.I engine using LHR and LTC in combination with biodiesel blends

Currently, the research of a single-cylinder 4-stroke direct injection diesel engine, which was naturally aspired, was used, and two modification methods were used. The first is the low-heat rejection method (LHR), and the second is the low-temperature combustion method (LTC). LHR was introduced into the engine by ceramic coating with alumina, which is applied to engine components such as the piston, cylinder lining, and valves and has a thickness of 300 microns without affecting the dimensions of the engine parts. In the next method, low - temperature combustion (LTC) method is done with EGR technique. And the exhaust gas recirculation setting (EGR) is included in the same setup as that of first method. Since, 15% of an exhaust gas is used in the EGR process. The diesel is blended with 20% of mahua biodiesel and 5% of ethanol as a fuel. After that, the engine performance is tested with conventional fuel when compared with biodiesel as a combined LHR and LTC methods. Finally, the engine output is increased by up to 3.48% as a result of the combination of LHR and LTC. As a result, emission levels could be dramatically decreased, and other results obtained could include a decrease in infrared radiation, resulting in a decrease in specific fuel consumption (SFC), and a substantial improvement in engine efficiency characteristics.

Effects of External Mixture Formation and EGR Technique on a Diesel-Fueled PCCI Engine

Limitations on exhaust emissions of diesel engines have become increasingly stringent due to increasing awareness of environmental protection. This challenges diesel engine manufacturers to find a new balance between engine performance and emissions. Advanced combustion modes for diesel engines, such as homogeneous charge compression ignition (HCCI) and premixed charge compression ignition (PCCI), which can simultaneously reduce exhaust emissions and substantially improve thermal efficiency, have drawn increasing attention. In order to allow enough time to prepare the homogeneous mixture, the external mixture formation technique was used to achieve PCCI combustion. A device known as diesel vaporizer was used to produce diesel vapors. Diesel vapors mix with air at intake port of an engine to form homogeneous charge before combustion starts. Exhaust gas recirculation technique was used to control early ignition of the premixed charge. It was observed from the experimentations that the use of external mixture formation technique with EGR in PCCI engine decreases the NOx emissions by 43.57% but increases HC and CO emissions due to low temperature combustion. The brake thermal efficiency obtained was just 1.9% less than the conventional CI engine.

Study of laminar burning speed and calibration coefficients of quasi-dimensional combustion model for hydrogen enriched compressed natural gas fueled internal combustion engine along with exhaust gas recirculation

Utilization of hydrogen fuel in internal combustion engine is regarded as a good choice due to its zero-carbon emission. The experiments have been performed under a wide range of operating conditions and the traces of in-cylinder pressures are obtained. The authors have formulated five laminar burning speed correlations (HCNG/N2, HCNG/N2/P, HCNG/CO2/T, HCNG/CO2/P & HCNG/CO) from the previous experimental work [25,31,33,34,38] while, two correlations (HCNG/N2/O2/T & HCNG/CO/CO2/T) have been imported from the earlier research work [32,35]. The iterations of these models have been staged in the quasi-dimensional combustion program of HCNG engine along with the exhaust gas recirculation but, results were un-satisfactory.Therefore, another laminar burning speed correlation (HCNG/N2/CO2/T) has been developed to improve the quasi-dimensional combustion model of HCNG fuel mixture along with the EGR technique. The kinetic GRI Mech3.0 mechanism has been utilized for the prediction of laminar burning speed of HCNG fuel mixtures at different hydrogen fractions 0 to 20% by volume in compressed natural gas, EGR ratios (0–0.3) and inlet temperatures (300–350 K). The effect of EGR ratio on the laminar burning speed in HCNG fuel mixture is introduced as the simultaneous impact of CO2 and N2 dilution of gases according to the balance chemical equation at stoichiometric condition. The presented model (HCNG/N2/CO2/T) is best suited for the quasi-dimensional combustion code of HCNG fuel mixture along with the exhaust gas recirculation as mean of the sample points of Taylor length & turbulent intensity coefficients are closer to 1 and minimum absolute percentage error for the indicated mean effective pressure.

Investigation on NOx control in SI Engine Assisted with Hot and Cold EGR

In this paper, we have conducted a study in a 2.2 kW variable speed SI engine coupled with electrical loading, whose main objective is to reduce the NOx emissions coming out of the engine. To achieve this outcome, we have opted for the EGR technique. We have opted for this technique because firstly it is a proven technique that has been successfully implemented in CI engine and secondly as it reduces the peak engine temperature leading to increased engine life. EGR is implemented by using EGR manifold which replaces the regular intake manifold. Also, a flow control valve is used to control the percentage flow of exhaust gases. From this study, we can conclude Cold EGR is effective in reducing NOx but lowers the efficiency. Additionally, a reduction in CO2 percentage is also observed at the cost of the increase in HC.

Experimental investigation on EGR technique and performance evaluation of diesel engine using diesel blend cotton seed oil as renewable fuel

Rising fossil-fuel prices and associated environmental pollution with their use have resulted in increased global interest in biodiesel production and use. The quest for bio-fuels has therefore been boosted throughout the world to protect the global environment and substitute bio-diesel fossil fuels. The objective is to evaluate the seed oil of cotton to be used as an alternative fuel. Cottonseed oil has diesel-like fuel properties. Cottonseed oil is mixed with diesel in different proportions viz 10%, 20%, 30%, 40% and tested in a single-cylinder diesel engine with exhaust gas recirculation. Bio-diesel is produced from cottonseed oil through a chemical process called transesterification. The country will face two major challenges in the next millennium, namely the energy crisis and the degradation of the environment. The day's weeping need is to have power, which means gas, more oil, and cheaper fuels in simple terms. The ever-increasing spending on imports of fuel oil is causing people's economic instability, price rises, and misery. In addition, grooving use of automobiles in our major metropolitan cities causes rapid degradation of the air environment due to vehicle exhaust pollution. There has been a growing demand for petroleum fuels over the past few years, the least petroleum fuels are stored fuel, extracted from the earth. With the petroleum fuels currently known and their increasing demand for consumption, it is feared that they will not last long. The performance and emission characteristics are calculated in this experimental with exhaust gas recirculation. It is investigated the viability and suitability of bio-diesel as an alternative diesel engine fuel with exhaust gas re-circulator. By comparison, the performance characteristics appear to be improved with the use of cottonseed oil for brake power, total fuel consumption, specific fuel consumption, and thermal efficiency, and NO and NOx are reduced.

Experimental analysis of performance and emission characteristics of CRDI diesel engine fueled with 1-pentanol/diesel blends with EGR technique

This research work aims to investigate the effect of higher alcohol blends on performance and emission parameters of CRDI CI engine with various EGR rate. 1-pentanol has improved fuel properties compared to lower alcohols. It can be used as a blend with diesel to mitigate the toxic emissions and to reduce the dependency on diesel fuel. The experiment was carried out in a CRDI CI engine with 1-pentanol/diesel blends (10%, 20% and 30% v/v) as a fuel, the speed of the engine kept constant (2000 rpm) by varying the load from 20 to 80% in step of 20%. Two EGR rates (10% and 20%) were also tested with blends to find the effect on engine characteristics. The performance of the engine reduces with higher 1-pentanol proportion in the blend. The experimental investigation showed that for P30D70 about 3.8% drop in BTE, 9.14% rise in BSFC, 16.7% drop in NOx emission and a slight rise in HC and CO emission was noted at 60% load. The smooth operation of the engine was noted with 1-pentanol/diesel blends and can be concluded that up to 30% of the 1-pentanol can be used as an alternative to the diesel with a slight cost of performance.

Effect of Cooled EGR Technique on Performance and Emissions of CRDI Engine Operated with Biodiesel Blends

Effect of Cooled EGR Technique on Performance and Emissions of CRDI Engine Operated with Biodiesel Blends

Performance and Emission Characteristics of Biodiesel Fueled Hydrogen Addition Engine Using EGR Technique

Performance and Emission Characteristics of Biodiesel Fueled Hydrogen Addition Engine Using EGR Technique

Investigations into CI Diesel Engine Performance and Emission Characteristics using Biodiesel with EGR Technique

Investigations into CI Diesel Engine Performance and Emission Characteristics using Biodiesel with EGR Technique

Influence of EGR and oxygen-enriched air on diesel engine NO–Smoke emission and combustion characteristic

The oxygen enriched combustion of diesel engines can reduce smoke emission and increase engine thermal efficiency; however it can also lead to an increase of NO emission. In this paper, experiment was conducted on a turbocharged direct injection diesel engine, and oxygen-enriched and EGR techniques were used to produce lower NO–Smoke emission than the unmodified engine under the same fuel supply rate curve and fuel supply quantity. The specific fuel consumption and the power loss were lower than 5% compared to the unmodified engine. The effect of oxygen enrichment on the particle size distribution was tested and analyzed. The results revealed that the optimal NO–Smoke emission can be achieved at these conditions: 1600rpm of engine speed, full load, 30–40% EGR rate and 21.5–22.5% of intake oxygen density; 2200rpm of engine speed, full load, 20–45% EGR rate and 22–24% of intake oxygen density. The result of particle size distribution tests revealed that oxygen enriched combustion can effectively suppress the diameter growth of particles and lead to fewer large particles with a diameter larger than 100nm emissions; however it did lead to an increase of 15nm small particles. A reduced n-heptane kinetic model was also developed in this research which contained NO and PAHs formation mechanisms, and the model was coupled with a CFD model to simulate the oxygen-enriched combustion of a diesel engine. The calculated results demonstrated that the coupled model can accurately predict ignition time and the change of in-cylinder pressure when the combined oxygen-enriched and EGR technique was used. The computed NO change with in-cylinder oxygen density agreed well with experiment results, and the computed result of the growth experience of PAHs showed that oxygen-enriched combustion can effectively suppress HACA reaction during PAHs formation, which leads to the reduction of large molecule PAHs, and this result agreed well with the observed situation that particle size diameter decreases with the increase of intake oxygen density.

Performance and exhaust emission characteristics of a CI engine fueled with biodiesel (fish oil) with DEE as additive

Abstract Oil provides energy for 95% of transportation and the demand of transport fuel continues to rise. According to the assessment of IPCC (International Panel on Climate Change) to climate change, global oil demand will rise by 60% from 75 Mb/d in 2000 to 120 Mb/d in 2030. Almost three quarter of the increase in demand will be form the transport sector. Oil will remain the fuel of choice in road, sea and air transportation. Our country being a developing country, the increase in demand in our country for oil for use in the transport sector will grow at a much higher rate. All countries including India are grappling with the problem of meeting the ever increasing demand of transport fuel with the constraints of international commitments, legal requirements, environmental concerns, and limited resources. In this context transport fuels of biological origin have drawn a great deal of attention during the last two decades. Biofuels are renewable liquid fuels coming from biological raw materials and have been proved to be good substitute for oil in the transportation sector. As such Biofuels ethanol and Biodiesel are gaining world wide acceptance as a solution for problems of environmental degradation, energy security, retracting imports, rural employment and agricultural economy. With a view to add Bio-Fish Oil to the list of biodiesel, experimental studies were made using this bio oil in a single cylinder diesel engine and generator set as substitute for diesel fuel and the results are discussed. It is also blended with oxygenate and EGR technique also used to improve the performance and reduce the emission of the engine. Encouraging results were obtained from this investigation. The percentage reduction is CO – 91%, CO2 – 62%, NOx – 92% and CxHy – 90% were attained when the engine was run at maximum load using BFO with 2% additive with EGR and there was reduction in all the percentages when the engine was run in other loads also. In the case of NOx, there was an increase of this emission by about 48% in the maximum load with BFO when compared with diesel, for obvious reasons and that was also reduced because of the addition of oxygenates and EGR technique. The optimum values were obtained with 2% of additive. When this percentage is increased or decreased the emission were increased.

An Experimental Investigation on the Potential of Hydrogen in the Reduction of the Emission Characteristics of an Existing Four-Stroke Single-Cylinder Diesel Engine Operating Under EGR

The present work attempts to explore the emission characteristics of an existing single-cylinder four-stroke compression-ignition engine operated in dual-fuel mode with hydrogen as an alternative fuel. Experimental investigation was carried out with the engine being subjected to different loads at a predefined flow rate of hydrogen induction. The emission characteristics revealed a 71% and a 40.5% reduction of CO2 emissions at 20% and 80% load, respectively, for non-EGR (exhaust gas recirculation) hydrogen enrichment. In CO emissions, non-EGR hydrogen enrichment registered a 69.5% and a 64.3% reduction at 20% and 40% load, respectively. Smoke emissions saw a 61.5% and a 64.3% reduction during non-EGR hydrogen enrichment at 20% and 40% load, respectively. Hydrocarbon (HC) emissions were reduced by 80% and 60.9% as compared with diesel operation at 20% and 60% loads, respectively. Hydrogen enrichment operations without EGR were penalized, however, with an increase of 79.3% and 81.3% in NOx at 40% and 60% load, respectively, as compared with diesel operation. EGR (hot and cold) technique has been implemented in the present work to reduce NOx emissions. In the present study, hydrogen enrichment overcome the inherent penalization of NOx–smoke tradeoff common under such EGR operation and was able to simultaneously decrease NOx emissions and smoke emissions effectively. As an indicator, 20% cooled EGR registered a decrease of 9.2% and 12.3% in NOx emissions at 60% and 80% load, respectively, as compared with diesel operation and simultaneously reduced smoke emissions by 10% and 8.3% as compared with diesel operation.

Development of automotive DI diesel engine to comply with stringent emission norms

Relatively lower fuel energy cost, higher fuel conversion efficiency and ability to take higher loads are the attracting features of direct injection diesel engines. However, diesel engines are still posing the challenges to both researchers and manufacturers in terms of high soot and NOx emissions. To overcome these difficulties, small diesel engine manufacturers are resorting to either upgrade their existing diesel engines to comply with the periodic revision in emission norms. A research work is taken-up to develop engines for complying with the stringent emission norms. To achieve the objective, an existing diesel engine is suitably modified in combustion chamber, fuel cam, fuel injection system and employed EGR technique. Performance optimisation tests are conducted on both engine and chassis dynamometers following the standard procedures of loading and vehicle driving cycles. 10% EGR is found to be optimum for engine performance and NOx emission reduction to achieve BS-III emission norms. With the design modifications incorporated added with 10%EGR about 85%, 32% and 75% reduction in CO, HC + NOx and PM emission respectively are obtained.

Effect of Gasoline Fumigation on Diesel Engine Performance and Emissions

The present study investigates theoretically the effects of gasoline fumigation on single-cylinder diesel engine performance and emissions. The results indicate that a premixed charge can be obtained by early injection of gasoline because of the high volatility of gasoline. More homogenous mixture was obtained and the fuel burned faster and efficient. The smoke emission was reduced and engine output was increased. Coupling with EGR technique could reduce the NOx emissions simultaneously.

Experimental analysis of a spark-ignition engine using exhaust gas recycle at WOT operation

Abstract Spark-ignition engines are still a competitive solution in a great number of applications. European manufacturers are all involved in the effort of improving fuel economy, at least at some engine operating points while meeting, of course, the pollutant emission standards. The EGR technique, since a long time adopted in reducing the NOx formation rate, could be an effective system for fuel economy improvement. Mainly, a de-throttle effect and decreased heat losses to the walls can be obtained in this way. Furthermore, lower exhaust gas temperatures can be reached thus avoiding damages to the noble metals of catalytic converters. In this paper, the EGR technique has been widely investigated by carrying out an experimental analysis of a small, naturally aspirated, spark-ignition engine. In particular, at full or high load operation, attention has been paid to the combustion development and the influence of EGR rate on the values of spark advance, at knock onset limit, tolerated by the engine has been assessed. Due to lower temperature levels within the combustion chamber, the obtained results show a decreased octane requirement, thus an optimal choice of spark advance is possible. Hence a significant increase of engine efficiency has been obtained.

Study of performance, combustion and emission characteristics of diesel homogeneous charge compression ignition (HCCI) combustion with external mixture formation

The present investigation was to study the performance, combustion and emission characteristics of homogeneous charge compression ignition (HCCI) combustion of diesel fuel with external mixture formation technique. A stationary four stroke, single cylinder, direct injection diesel engine capable of developing 4.4 kW at 1500 rpm was modified to operate in HCCI mode. To achieve homogeneous mixture, diesel fuel was inducted in vapour form by using a diesel fuel vaporizer. The fuel vaporizer was mounted in the intake system to provide diesel vapour, which is mixed with air and inducted into the cylinder. To control the early ignition of diesel vapour–air mixture, cooled EGR technique was adopted. Experiments were conducted with diesel vapour induction without EGR and diesel vapour induction with 10% EGR and results are compared with conventional diesel fuel operation (DI @ 23 deg bTDC and 200 bar injection pressure). From the experimental results, it is found that, the ignition delay is reduced considerably for diesel vapour induction due to better mixture preparation and results in low emissions. A reduction of about 55% and 80% in NO x emissions and 20% and 30% reduction in smoke emissions are obtained for diesel vapour induction without EGR and Diesel vapour induction with 10% EGR compared to conventional mode of operation.