Turbocharged DI Diesel Engine Research Articles

Comparative Numerical Study of Four Biodiesel Surrogates for Application on Diesel 0D Phenomenological Modeling

To meet more stringent norms and standards concerning engine performances and emissions, engine manufacturers need to develop new technologies enhancing the nonpolluting properties of the fuels. In that sense, the testing and development of alternative fuels such as biodiesel are of great importance. Fuel testing is nowadays a matter of experimental and numerical work. Researches on diesel engine’s fuel involve the use of surrogates, for which the combustion mechanisms are well known and relatively similar to the investigated fuel. Biodiesel, due to its complex molecular configuration, is still the subject of numerous investigations in that area. This study presents the comparison of four biodiesel surrogates, methyl-butanoate, ethyl-butyrate, methyl-decanoate, and methyl-9-decenoate, in a 0D phenomenological combustion model. They were investigated for in-cylinder pressure, thermal efficiency, andNOxemissions. Experiments were performed on a six-cylinder turbocharged DI diesel engine fuelled by methyl ester (MEB) and ethyl ester (EEB) biodiesel from wasted frying oil. Results showed that, among the four surrogates, methyl butanoate presented better results for all the studied parameters. In-cylinder pressure and thermal efficiency were predicted with good accuracy by the four surrogates.NOxemissions were well predicted for methyl butanoate but for the other three gave approximation errors over 50%.

Experimental investigation of the effects of using low ratio n-butanol/diesel fuel blends on engine performance and exhaust emissions in a turbocharged DI diesel engine

The aim of this paper is to investigate the effects of the using of low ratio n-butanol/diesel fuel blends on the engine performance and exhaust emissions in a turbocharged automobile diesel engine. Experiments have been performed for different n-butanol/diesel blends, kept at low blending ratios, nB2 (nB2 contains 2% n-butanol and 98% diesel fuel in volume basis), nB4 and nB6, at different engine speeds and loads. The test results showed that engine characteristics and nitrogen oxides (NOx) emission improve for nB2 and nB4 at selected engine speeds and loads. However, they deteriorate for nB6. At the end, nB2 was determined as the most favorite blend for engine characteristics and NOx. Smoke reduces for nB2, nB4 and nB6 at all of the selected engine speeds. n-Butanol/diesel fuel blends provide little effect on the in-cylinder pressure and heat release rate of this engine at selected operating conditions. However, total fuel cost for used n-butanol/diesel fuel blends becomes higher than diesel fuel.

NUMERICAL AND EXPERIMENTAL INVESTIGATIONS OF EGR DISTRIBUTION IN A DI TURBOCHARGED DIESEL ENGINE

This paper presents the results of numerical and experimental investigations to evaluate the distribution of exhaust gas recirculation (EGR) between cylinders in a DI turbocharged diesel engine. The turbulent three-dimensional flow field was analyzed by the numerical solution of conservation equations with an appropriate turbulence model. EGR was applied to intake manifold with various rates at cooled and non-cooled states. The experiments were conducted on an MT4.244 turbocharged DI diesel engine under full load condition at 1900rpm. The model was validated by experimental data with a good agreement between experimental measurements and numerical predictions. Using this method, it is possible to control EGR distribution so as to reduce emissions formation as well as to improve performance.

Multidimensional modeling of the effect of fuel injection pressure on temperature distribution in cylinder of a turbocharged DI diesel engine

In this study, maintaining a constant fuel rate, injection pressure of 275bar to 1000bar (275×102kPa to 1000×102kPa), has been changed. Effect of injection pressure, the pressure inside the cylinder on the free energy, power, engine indicators, particularly indicators of fuel consumption, pollutants and their effects on parameters affecting the output of the engine combustion chamber have been studied in droplet diameter. Finally, the effects of fuel mixture equivalence, Cantor temperature, soot and NOx due to the increase of injection pressure, engine efficiency and emissions have been examined.

Experimental Studying of the Effect of EGR Distribution on the Combustion, Emissions and Perforemance in a Turbocharged DI Diesel Engine

This paper presents the results of experimental work carried out to evaluate the distribution of cold and hot exhaust gas recirculation between cylinders in a DI diesel engine. The experiments have been conducted on a 3.99 liters turbocharged DI diesel engine under full load condition at 1900rpm in order to distinguish and quantify some effects of hot and cooled EGR with various rates on the EGR distribution and engine parameters. Experimental results showed that with increasing of EGR rate, unequal EGR distribution was increased in inlet port of cylinders while the reducing of EGR temperature (cooled EGR) improved this distribution and decreased the EGR cylinder-to-cylinder variations.

Control Strategy and Realization of Dual Fuel Engine with Intake Premixed Methanol on Turbocharging Diesel Engine

Based on Methanol and diesel special combustion mode, a control strategy of methanol/diesel dual fuel engine on turbocharged DI diesel engine was introduced according to different operation conditions. A method of judging engine load by measuring intake manifold pressure was put forward. Bicubic interpolation method was adopted to optimize the control MAP for ensuring the coincidence between look-up table data and actual conditions. The feasibility of the control strategy is verified by bench test. And the results of test show that the economic performance of this dual fuel engine got a considerable improvement.

An investigation of the impact of injection strategy and biodiesel on engine NOx and particulate matter emissions with a common-rail turbocharged DI diesel engine

An investigation of the impact of engine injection strategy on NOx and particulate matter (PM) emissions with biodiesel fueling was conducted with a common-rail turbocharged direct injection diesel engine at moderate speed and different load/torque conditions. The fuels included a baseline ultra low sulfur diesel fuel (ULSD) and a B40 (v/v) blend of a soybean methyl ester (SME)-based biodiesel and ULSD. Single fuel injections at start of injection timings over a range from 9° before to 3° after top dead center with different fuel injection pressures were investigated. It is found that at all load conditions, an increase of fuel injection pressure significantly increases NOx emissions, and that with the same injection strategy as the baseline diesel, biodiesel fueling increases NOx emissions. For particulate matter emissions, it is found that an increase of fuel injection pressure decreases PM emissions for all load conditions. Meanwhile, biodiesel fueling has a more significant effect on PM emissions at low load and a less significant effect at moderate to high load. For an engine running with early SOI (highest brake fuel conversion efficiency in this work), a decrease of fuel injection pressure can counter the biodiesel NOx effect while maintaining a similar or even lower level of PM emissions as ULSD. Both biodiesel fueling and the change of fuel injection pressure did not significantly affect the brake fuel conversion efficiency, but retarding the start of injection appears to decrease it. Apparent heat release analysis shows a faster and higher heat release peak with higher fuel injection pressure. With biodiesel fueling, an earlier of start of combustion can be observed for low load, but no significant difference in combustion phasing can be observed at moderate to high loads. A fuel spray, mixture stoichiometry field and lift-off length model was employed. Linear correlations between the average oxygen equivalence ratio of the fuel–air mixture at the autoignition zone near the lift-off length and brake specific NOx emissions were observed for all load conditions, regardless of fuel type. This confirms that the dominant factor that determines NOx emissions is the ignition event controlled by the oxygen equivalence ratio at the autoignition zone.

Soot emission prediction of a waste-gated turbo-charged DI diesel engine using artificial neural network

This study is about soot emission prediction of a waste-gated turbo-charged DI diesel engine using artificial neural network (ANN). For training the ANN model, six ranges of experimental data in previous study were used, and one range of data was kept for testing the accuracy of ANN predictions. The input parameters for the ANN are inlet manifold pressure, inlet manifold temperature, inlet air mass flow rate, fuel consumption, engine torque, and speed. Output parameter is the density of soot in the exhaust. The results show the ANN approach can be used to accurately predict soot emission of a turbo-charged diesel engine in different opening ranges of waste-gate (ORWG). Root mean-squared error (RMSE), fraction of variance (R 2), and mean absolute percentage error (MAPE) for predictions were found to be 1.19 (mg/m3), 0.9998, and 6.4%, respectively.

An experimental study on the effects of different opening ranges of waste-gate on the exhaust soot emission of a turbo-charged DI diesel engine

This experimental study was conducted to investigate the effects of different opening ranges of waste-gate of a turbo-charged DI diesel engine on improving the exhaust soot emission. Different opening ranges of waste-gate were supplied using an adjustable spring to load the actuating rod of the waste-gate in which, increasing the opening range of the waste-gate decreases the inlet manifold pressure. In this study, the maximum inlet manifold pressures which were supplied by changing the opening range of waste-gate were 0.1 bar, 0.23 bar, 0.26 bar and 0.52 bar over atmosphere and experiments were conducted under the ECE-R49, 13 mode standard test. At each mode of the test, soot emission was recorded and then brake specific soot emission was calculated. Results indicate that, soot emission decreases with increasing the maximum inlet manifold pressure from 0.1 bar to 0.23 bar. This reduction may be due to increasing the intake-air temperature which results in reduction of ignition delay that prolongs the late combustion phase. This improves the soot burnout process because enough time and sufficient in-cylinder temperature are available at the late combustion phase prior to exhaust valve opening. While for the higher maximum inlet manifold pressures from 0.23 bar to 0.52 bar, although there are enough time at the late combustion phase, but the soot emission increases which could be due to more reduction of the in-cylinder gas temperature at the end of combustion before EVO.

Combustion characteristics of a turbocharged DI compression ignition engine fueled with petroleum diesel fuels and biodiesel

In this study, the combustion characteristics and emissions of two different petroleum diesel fuels (No. 1 and No. 2) and biodiesel from soybean oil were compared. The tests were performed at steady state conditions in a four-cylinder turbocharged DI diesel engine at full load at 1400-rpm engine speed. The experimental results compared with No. 2 diesel fuel showed that biodiesel provided significant reductions in PM, CO, and unburned HC, the NO x increased by 11.2%. Biodiesel had a 13.8% increase in brake-specific fuel consumption due to its lower heating value. However, using No. 1 diesel fuel gave better emission results, NO x and brake-specific fuel consumption reduced by 16.1% and 1.2%, respectively. The values of the principal combustion characteristics of the biodiesel were obtained between two petroleum diesel fuels. The results indicated that biodiesel may be blended with No. 1 diesel fuel to be used without any modification on the engine.

1804 小型高過給 DI ディーゼル機関の負荷と各部応力特性について

1804 小型高過給 DI ディーゼル機関の負荷と各部応力特性について

The effect of biodiesel oxidation on engine performance and emissions

Biodiesel is an alternative fuel consisting of the alkyl monoesters of fatty acids from vegetable oils or animal fats. Previous research has shown that biodiesel-fueled engines produce less carbon monoxide, unburned hydrocarbons, and particulate emissions compared to diesel fuel. One drawback of biodiesel is that it is more prone to oxidation than petroleum-based diesel fuel. In its advanced stages, this oxidation can cause the fuel to become acidic and to form insoluble gums and sediments that can plug fuel filters. The objective of this study was to evaluate the impact of oxidized biodiesel on engine performance and emissions. A John Deere 4276T turbocharged DI diesel engine was fueled with oxidized and unoxidized biodiesel and the performance and emissions were compared with No. 2 diesel fuel. The neat biodiesels, 20% blends, and the base fuel (No. 2 diesel) were tested at two different loads (100 and 20%) and three injection timings (3° advanced, standard; 3° retarded). The tests were performed at steady-state conditions at a single engine speed of 1400 rpm. The engine performance of the neat biodiesels and their blends was similar to that of No. 2 diesel fuel with the same thermal efficiency, but higher fuel consumption. Compared with unoxidized biodiesel, oxidized neat biodiesel produced 15 and 16% lower exhaust carbon monoxide and hydrocarbons, respectively. No statistically significant difference was found between the oxides of nitrogen and smoke emissions from oxidized and unoxidized biodiesel.

Effect of Nozzle Orifice Size on Soot Particle Size in a DI Diesel Engine.

The effect of nozzle orifice size on smoke emission was examined experimentally in a turbocharged DI diesel engine. The nozzle orifice size was varied from 0.26 to 0.18 mm under various engine operation condition. The rates of NO-formation, soot-formation and soot-oxidation were analyzed by using the two-zone model based on the measured combustion pressure time history. The changes due to orifice size in the excess air ratio of the burned zone, the soot particle size and the number of soot particles were estimated. It is shown that the soot size is primarily dependent on the orifice size and secondarily but more markedly on the spray penetration for the ignition delay period, and the number of soot particles is primarily dependent on the amount of fuel injected and secondarily on the excess air ratio of the burned zone.

Simultaneous Reduction of NOx and Smoke based on Port Injection of Methanol/Water Blend in a DI Diesel Engine.

The auxiliary port injection system was built up using low pressure injectors installed on a commmon rail. Methanol/water blend was injected into each suction port of a four cylinder turbocharged DI diesel engine by controlling the injection timing and duration electronically. The optimum conditions of the injected amount of methanol/water blend and the blending ratio of methanol and water were investigated to obtain simultaneous reduction in both NOx and smoke without increasing fuel consumption. In the theoretical study, the effect of methanol/water blend on combustion and NO formation was analyzed by using the two-zone model. The proposed auxiliary port injection of meth anol/water blend combined with the pilot fuel injection could be a feasible countermeasure.

NOx Reduction in Diesel Engines due to Port Water-Injection. Comparison of NOx Reduction Rate between Experiment and Prediction.

The effect of port water-injection on the exhaust NOx reduction was examined experimentally as well as theoretically. In the experiment, water was injected into each suction port of a 4 cylinder turbocharged DI diesel engine using gasoline injectors. The exhaust NOx was reduced significantly by port water-injection, and about 50% reduction in NOx concentration was obtained by injecting an amount of 0.035kg of water/kg of air under various engine operation conditions. By comparing between the experiment and the analysis based on the authors' two-zone model, it is shown that the NOx reduction is mainly caused by a decrease in the temperature of the burned gas resulting from an increase in the specific heat due to humidification.

96/05341 The study of thermodynamic cycle and entropy change in a turbocharged DI diesel engine

A software program has been developed for calculating the thermodynamic cycle, in particular the entropy changes, in a turbocharged direct-injection diesel engine, based on the measured cylinder pressure and the output of a shaft encoder. Assumptions of homogeneous mixture and equilibrium thermodynamic properties are made for the products of combustion, and the temporal variation in the fluid thermodynamic state is followed in a quasi-steady manner through a series of adjacent equilibrium states, separated by finite intervals of 1° crank angle. Calculations of the thermodynamic properties and equilibrium chemical products of fuel-air reaction are based on the method of minimising Gibbs free energy with a flexibly defined number of product species. The effect of the engine operating conditions on the thermodynamic cycle is studied. Results show that the dynamic fuel-injection timing, and hence ignition delay, are strongly influenced by the operating conditions, and this explains the reasons for incorporating a fuel-injection control system in modern vehicular engines for optimising the engine combustion cycle. The effect of fuel-injection timing on the thermodynamic cycle is also studied with 8 °CA retard and advance reference to the base-line fuel-injection setting.