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Exhaust gases temperature evolution at different fuel injection strategies (at engine full load-100 %).
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In general, the efficiency of the currently used aftertreatment solutions is strongly conditioned by the temperature of the exhaust gases. The regeneration capability of the aftertreatment equipment can be improved by intentionally rising the temperature of the exhaust gases. When using technologies like hybrid transmission, engine Start/Stop and c...
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... Materials Science and Engineering 444 (2018) 072016 doi:10.1088/1757-899X/444/7/072016 Figure 7 shows the influence of the number of injections on T gas , with the engine functioning at full load (100 %). The fuel injection strategy per cycle was modified three times, as follows: main injection, one and two pre-injections. ...
Citations
... The first perspective is the investigation of the temperature and temperature gradient during the thermal regeneration of DPF, and the related studies have been summarized in Table 4. Another perspective of the study focused on adopting advanced in-cylinder combustion control technologies, such as multi-point injection (MPI) strategy, exhaust pipe pressure (EMP) control, intake throttle, and late exhaust valve opening (LEVO). Roberts et al. (2015) and Gosala et al. (2018) demonstrated using the early opening of the exhaust valve to increase the engine outlet temperature by reducing the closed cycle efficiency (Leahu et al. 2018). Exhaust valve adjustment to reintroduce residual gas improved cold-start emissions, which coupled with delayed injection helped increase the engine exhaust temperature (Maniatis et al. 2019a, b). ...
With the global emphasis on environmental protection and the proposal of the climate goal of “carbon neutrality,” countries around the world are calling for reductions in carbon dioxide, nitrogen oxide, and particulate matter pollution. These pollutants have severe impacts on human lives and should be effectively controlled. Engine exhaust is the most serious pollution source, and diesel engine is an important contributor to particulate matter. Diesel particulate filter (DPF) technology has proven to be an effective technology for soot control at the present and in the future. Firstly, the exacerbating effect of particulate matter on human infectious disease viruses is discussed. Then, the latest developments in the influence of key factors on DPF performance are reviewed at different observation scales (wall, channel, and entire filter). In addition, current soot catalytic oxidant schemes are presented in the review, and the significance of catalyst activity and soot oxidation kinetic models are highlighted. Finally, the areas that need further research are determined, which has important guiding significance for future research. Current catalytic technologies are focused on stable materials with high mobility of oxidizing substances and low cost. The challenge of DPF optimization design is to accurately calculate the balance between soot and ash load, DPF regeneration control strategy, and exhaust heat management strategy.
... The lowest values of EG temperature and cyclic fuel supply with the SLFAC operation indicate the more efficient work process [15] with the FAC stratification relative to the operation with LFAC [16]. ...
The results of experimental studies on load characteristics (3000 rpm) of a two-stroke engine 1D 8.7 / 8.2 with spark ignition, crankcase scavenging, air cooling, and direct fuel injection have been considered in the paper. Changing the design of the combustion chamber and spray nozzle allowed accomplishing different patterns of fuel and air charge formation. Forming lean fuel-air mixture (1.5>λcyl>1.0) is carried out at fixed composition in the clearance volume. Forming rich fuel-air mixture (1.0>λ>0.8) in the spark plug area with the air at λcyl<5 near the clearance volume walls enables the generation of a stratified fuel-air charge. Forming lean fuel-air mixture (1.5>λ>1.0) in the spark plug area with the air λcyl<5 near the clearance volume walls enables the generation of a stratified lean fuel-air charge. It has been revealed that generating the stratified lean fuel-air charge allows a reduction of fuel consumption by 16–27 % and a decrease in CO and CH emissions with exhaust gases up to 14 times in comparison with the generation of lean fuel-air charge.
... The heat energy accumulated in exhaust gases is transferred to the environment through walls of the exhaust system as well as external surfaces of compressor, and therefore it is necessary to determine temperatures of individual components [36÷38]. The temperature of exhaust system components should reach values that are safe for composite materials and plastics, as their damage could have fatal consequences [39]. By knowing thermal emission values of the system, it is possible to redesign the exhaust system so that when built into an aircraft it does not come into close contact with thermally sensitive components [40÷42]. ...
In ultralight aviation, a very important engine parameter is the power-to-weight ratio. On the one hand, there is a tendency to minimize the size and weight of engines, and on the other hand, there is a demand to achieve the highest possible power by using supercharging systems. Increasing power brings many benefits, but it also increases temperature in the exhaust system, posing a threat to delicate parts of the ultralight aircraft fuselage. Therefore, it is necessary to control temperature values in the engine exhaust system.
This article presents the temperature distribution in the exhaust system of an aircraft engine by the example of a four-cylinder Rotax 912 engine with an electronic fuel injection system. The research was conducted in two stages: measurements were made first for the engine without a turbocharger with an original exhaust system and later for its modified version with an added turbocharger system. The paper presents a comparative analysis of exhaust gas temperatures measured at three points: 30, 180 and 1000 mm from the cylinder head. The tests were conducted for the same preset engine operating conditions at constant speed and manifold air pressure.
It has been shown that the exhaust temperature in the exhaust manifold decreases with the distance from the cylinder head. The highest gradient, over three times higher than the gas temperature from 589.9 °C to 192.3 °C, occurred in the manifold with a turbocharger for 2603 RPM and 31 kPa of manifold air pressure. The introduction of turbocharging causes an increase in exhaust gas temperatures before the turbocharger by an average of 12%, with this increase being greater for operating points of higher inlet manifold pressure. Turbocharging also causes a significant decrease in exhaust gas temperatures behind the turbocharger and the silencer because the temperature drops there by an average of 25%.
... [22]. Exhaust gas temperature affects on the performance and emissions is observed by Leahu et al. [23]. Damma [27]. ...
This study focuses on different intelligent time series modelling techniques namely nonlinear autoregressive network with exogenous inputs (NARX), autoregressive integrated moving average with external inputs (ARIMAX), multiple linear regression (MLR), and regression error with autoregressive moving average (RegARMA), applied on a diesel engine to predict NOx emission and fuel consumption. The experiment data are collected from a six cylinder, four stroke medium duty truck diesel engine, which is integrated on a passenger bus and operated in engine integration tests. NOx emission and fuel consumption outputs are estimated with the help of input data; exhaust gas recirculation temperature and position, engine coolant temperature, engine speed, exhaust gas pressure, common rail pressure, intake manifold air temperature and pressure, accelerator pedal percentage, engine load, turbocharger variable geometry position and speed, and selective catalytic reduction outlet temperature. NARX artificial time series neural network, MLR, ARIMAX, and RegARMA time series techniques were separately applied for the estimation NOx emission and fuel consumption outputs. The performance of the models is analyzed and evaluated with Bayesian information criterion (BIC) and root mean square error (RMSE) criteria. When the high cost and time loss of experimental testing are thought, using the intelligent modelling methodology provides far more accurate prediction and fast application abilities to analyze internal combustion engine dynamics for the control and calibration manner. As a result of the comparison of different types of modelling techniques, RegARMA technique comes to the forefront with 6707.6 BIC value with 105.58 RMSE for NOx emission model and 4026.4 BIC value with 7.93 RMSE for fuel consumption model.
... A good management of the thermal regime of the engine can reduce pollutant emissions [8,9] so, the model proposed in this paper can offer useful information about the thermal regime of the GDI engines. ...
Based on an own model, the authors have realized the analytical calculus of the temperatures in the characteristic points of the thermodynamic cycle for a GDI engine. These temperatures were calculated depending on the engine’s rotational speed and on the environmental temperature (considered to be equal to the one in the intake valve port) and for an excess air factor λ=1. The first step was the development of the mathematical model of the engine’s cycle. The model includes the presentation of the initial data for the thermal calculus and the correlation between the expressions of the parameters in order to develop the computing programs. The calculated data were compared with experimental data acquired at environmental temperature, at maximum power and at the rotational speed corresponding to the maximum power (full load). The results show that the proposed model is accurate enough to be a useful tool for the study of GDI engines.
... That means that a poor air-fuel mixture (with oxygen in excess) it is formed in cylinders, which burns at high temperature. These two conditions lead to generating a significant amount of NOx emissions -which makes more difficult to meet the Euro 6 pollution standard [4,5,6]. It could be noticed that by passing from the pollution standard Euro 5 to Euro 6 one, the NOx emissions have been significantly reduced, the differences between the two standards reaching values up to 80%. ...
... It could be noticed that by passing from the pollution standard Euro 5 to Euro 6 one, the NOx emissions have been significantly reduced, the differences between the two standards reaching values up to 80%. These reductions of NOx emissions were made possible mainly due to the utilization of the following equipment and procedures: exhaust gas recirculation (EGR), Diesel Oxidation Catalyst (DOC), Lean NOx Trap (LNT) and Selective Catalytic Reduction Technology (SCRT) [5,7,8]. ...
The overwhelming parts of the modern Diesel engines for vehicles are supercharged. However, the supercharging process lead to generating a significant amount of NOx emissions. Therefore, the supercharging intensity may be intentionally limited in order to avoid increasing NOx emissions excessively, as these emissions are drastically limited by the Euro 6 pollution standard. By moving from Euro 5 to Euro 6, the NOx emission’s permissible limits have been reduced by up to 80%. These reductions of NOx emissions were made possible mainly due to the utilization of the some conventional equipment and procedures presented in the paper. Diesel engine’s supercharging could be realized efficiently also with pressure wave compressor (PWC). The paper highlights the possibility of realizing the EGR process directly through the PWC. The concept of supercharging with PWC leads to a significant reduction of NOx, for a significant increase of both the pressure and temperature of the intake air.
Gasoline compression ignition (GCI) mode engines are characterized by partially premixed charge combustion, leading to significant and simultaneous reductions of nitrogen oxides and particulate matter emissions. However, gasoline compression ignition engine operation suffers from a limited operating window. Air preheating and low-research octane number fuels are required to improve the engine performance. This experimental study used a blend of 70% (v/v) gasoline and 30% diesel as test fuel in a direct injection medium-duty compression ignition engine. Experiments were carried out at 5- and 10-bar brake mean effective pressure (BMEP) engine loads at 1500–2500 rpm engine speeds using a triple injection strategy (two pilots and one main injection) for all test conditions. The combustion phasing was kept constant with respect to crank angle to produce a high power output. The investigations examined engine performance and regulated and unregulated emissions. The test engine was initially operated in conventional diesel combustion mode with diesel for baseline data generation. Gasoline compression ignition mode operation demonstrated a remarkable 16% increase in the brake thermal efficiency and a substantial reduction of 65% in nitrogen oxide emissions compared to the baseline conventional diesel combustion mode. The GCI engine exhaust showed higher concentrations of regulated emissions, namely hydrocarbons and carbon monoxide, and unregulated trace emissions, such as methane, acetylene, toluene, inorganic gaseous species, and unsaturated hydrocarbons.
Significant aspects of the consequences of global warming and some measures that can be undertaken in order to reduce energy consumption and harmful emissions have been presented. The most important actions I this field are related to the renewal of the design of automobile vehicles and their components. A theoretical survey has been carried out in two main areas: invesitigating possibilities of improving the operational characteristics and the design parameters of transmissions and gearboxes, aiming to identify the areas of future dissertation research. A systematization of the reviewed scientific publications has been carried out. Main areas in which additional research can be carried out, related to the specific features of the Bulgarian industry and the state of the available cars in usage, have been identified.
In this study, the effects of JP-8 military aviation fuel and biodiesel sunflower oil on the performance and emissions of the internal combustion engine were investigated by creating a mixture of fuel in different concentrations. Experimental and statistical methods were used in the study process. All of the experiments were carried out on an experimental setup with a single-cylinder compression-ignition engine at 7.5, 12.5 and 17.5 Nm engine load conditions. A total of 5 different fuels were used, including pure JP-8 fuel, 3 different blended fuels and pure biodiesel fuel. The design of the Response Surface Method, which is used as a statistical method, was carried out with Central Composite Design in the Design Exper 11 program environment. After the created design, 13 different experiments were carried out. With the tests performed, the values of IMEP, BSFC, COVimep, ignition delay, equivalence ratio, exhaust gas temperature, CO, and NOx emission response parameters were determined. Quadratic models were created by performing variance analysis for the response parameters obtained. After the optimization, it was concluded that the engine load should be 14.49 Nm and the JP-8 fuel biodiesel ratio should be 2.47%. In case the internal combustion engine is operated with optimum input parameters, IMEP value is 3.71 bar, BSFC value is 193.46 g/kWh, COVimep value is 5.99 bar, CO value is 724 ppm and NOx value is 168.62 ppm.
The article presents ceramic and metal substrate filtration efficiency in the particulate filter of a spark-ignition engine with direct fuel injection. Gaseous exhaust components were taken into account. There are many publications on the solid particles mass and number reduction, so the authors examined the effect of catalytic carriers on gaseous compounds, such as CO, NOx, THC, whose content also poses a threat to human health and life, and this issue is not often described in the literature dedicated to measurements of modern internal combustion engines. During the tests, the length and carrier material effect on the emission of harmful substances in exhaust gases was determined.
