TDI Diesel Engine Research Articles

Effects of Biodiesel Fuels Produced from Vegetable Oil and Waste Animal Fat on the Characteristics of a TDI Diesel Engine

In this study, four different biodiesel fuels obtained from corn oil, safflower-rapeseed oil mixture (50%-50% v/v), waste chicken fat, and waste fleshing oil were tested in a six-cylinder, water-cooled, TDI diesel engine. Vegetable oil and waste animal fat origin biodiesel fuels’ effects on the performance, injection, combustion and emission characteristics of test engine were compared with each other and petroleum-based diesel fuel as reference fuel. Biodiesel fuels (regardless of their feedstock) increased in-cylinder gas pressure, brake specific fuel consumption, and NOx emissions while decreased THC and CO emissions compared to pure diesel fuel. In comparison to petro-diesel, the start of fuel injection timing advanced but the end of fuel injection timing retarded with biodiesels. In addition, comparatively higher fuel injection pressure values were attained with all biodiesel fuels. Waste animal fat and vegetable oil origin biodiesel fuels showed similar in-cylinder gas pressures, fuel injection characteristics and brake specific fuel consumption values. However, CO emissions of vegetable oil-based biodiesel fuels were lower and NOx emissions were higher than those of waste animal fat-based biodiesels.

Optimizing cetane improver concentration in biodiesel-diesel blend via grey wolf optimizer algorithm

Biodiesel and their blends with diesel have long been used as alternative fuels in diesel engines. In particular, B20 is recommended in most studies since it reduces the exhaust emissions and provides satisfactory engine torque close to diesel fuel. On the other hand, low cetane number of biodiesel leads to higher oxides of nitrogene (NOx) emission when compared to those of the diesel fuel. Formation of NOx emissions has a strong correlation with cetane number of fuels, which increases with the reduction of the cetane number. The current paper focuses on finding the optimum 2-ethylhexyl nitrate (EHN) (cetane improver) concentration and the engine speed for 20 vol% canola oil methyl ester and 80 vol% diesel fuel blend (B20). For that reason, experimental design is created and the experiments have been done on TDI diesel engine at full load and different engine speed conditions to be able to model the problem as an optimization problem by means of the regression modelling. Accordingly, the developed model in consequence of the test results of the engine is optimized via the grey wolf optimizer (GWO) algorithm taking into account of engine performance and emission parameters viz. brake torque, brake power, brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), NOx, and carbon dioxide (CO2), to identify the rate of concentration of EHN in B20 and engine speed. Finally, confirmation tests were employed to compare the output values of the concentration that were identified through the GWO algorithm, and further statistical analyses indicate the consistency between the real experimental results and the results obtained through the GWO algorithm. The optimum EHN concentration and engine speed was determined as 743 mg/L and 3221 rpm respectively. Test results of engine performance indicated that brake power and BSFC of optimum blend at 3221 rpm decreased while brake torque and BTE increased in comparison with those of B20 without EHN. CO2 and NOx exhaust emissions decreased as 11.19% and 4.63% respectively.

Complex analysis focused on influence of biodiesel and its mixture on regulated and unregulated emissions of motor vehicles with the aim to protect air quality and environment

The main task of this study is to perform a complex analysis dealing with influence of biodiesel and its mixture on regulated and unregulated gaseous emissions of diesel engine, which is installed in a motorcar as a driving unit determined for standard road traffic. As a real technical platform intended for realisation of the required experiments, a motor vehicle equipped with the TDI engine was chosen because just this kind of engine was directly affected by the affair “dieselgate”. This type of piston combustion engine is widely used in the traffic, together with negative impacts on the air quality. Various diesel fuel mixtures, which represented the applied experimental fuels, were created by mixing of the ultra-low sulphur diesel fuel (ULSDF) with the biodiesel, using different mixture ratios. The individual experiments were performed during a 13-mode test cycle especially developed for the diesel engine in such a way, so that it was possible to identify influence of the engine loading and engine speed on the regulated and unregulated gaseous emissions of the given TDI diesel engine. It is possible to say according to the obtained results that a higher portion of the biodiesel in the fuel mixture reduces the amount of the hydrocarbons (HC), carbon monoxide (CO) and particulate matters (PM) in the gaseous emissions, but it increases volume of the nitrogen oxides (NOX). A higher portion of the biodiesel causes a growth of the formaldehyde emissions and acetaldehyde emissions in the case of unregulated diesel engine emissions. The same trend is also typical for the 1,3-butadiene, propene and ethene. The biodiesel additive increases emissions of benzene; however, it reduces emissions of the toluene and xylene within the aromatic substance emissions. The obtained results confirm a fact that all the gaseous emissions are influenced by the engine operational regimes, especially by the engine loading status.

Sincerest Form of Flattery? Product Innovation and Imitation in the European Automobile Industry

I study the impact of imitation on the returns to technological innovation when products are differentiated. Using data that capture Volkswagen’s introduction of the TDI diesel engine and the technology’s imitation by rival European firms, I estimate a discrete choice, oligopoly model of horizontally differentiated products. Imitation benefited consumers by increasing product variety and reducing prices but also limited Volkswagen to 14% of potential profits from the TDI. Volkswagen’s ability to differentiate its diesel models made the TDI a worthwhile investment nonetheless. This indicates firms can mitigate imitation risk by bundling easy‐to‐copy technological advancements with difficult‐to‐copy product characteristics including brand.

Biodiesel production from waste cooking oil in an oscillatory flow reactor. Performance as a fuel on a TDI diesel engine

Abstract This paper describes the biodiesel production from waste cooking oil (50% (v/v) olive oil/sunflower oil) in an oscillatory flow reactor (OFR) in batch mode. We mainly focused on the characteristics of the biodiesel and its performance as a fuel. First at all, we verified that biodiesel yield in OFR was higher than in stirred tank reactor (STR) under the same experimental conditions, and that composition and properties of the resulting biofuel did not depend on reactor type. Besides, biodiesel production in OFR took half the time than in STR. Subsequently, we modify some OFR operational parameters to assess their influence on biodiesel yield. The most suitable conditions were found to be 6:1 methanol to waste cooking oil molar ratio, 0.67 Hz oscillation frequency and 30 min reaction time. Finally, the biofuel obtained was tested in a 2.0 TDI 140 hp EURO4 engine installed on an engine test bench. Specific fuel consumption, particle size distribution and concentration of exhaust gas sample pollutants and were analysed running with commercial diesel, 50% (v/v) diesel/biodiesel blend (B50) and biodiesel (B100) in order to ensure the viability of using this biofuel in vehicle engines.

Influence of hydrogen addition on combustion characteristics and particle number and size distribution emissions of a TDI diesel engine

The aim of the study is to evaluate the influence of hydrogen addition on the combustion process, the specific fuel consumption, brake thermal efficiency and emissions, especially particle emissions in the range 5.6–560nm in size distribution and number of a diesel engine. The tests were performed on a 2.0 TDI diesel engine VW Euro 4, in nine stable conditions (2000, 2500, and 3000min−1 at 15%, 30% and 45% engine load) with 0% of H2 and substituted 25% of energy from diesel fuel by H2. Experimental result shows that if we substitute 25% of the energy released in the combustion process with energy from hydrogen, the rate of decrease in the emission of CO2 reaches up 22% for a load of 15% and 2500min−1, the expected 25% reduction is not achieved due to a slight decrease in brake thermal efficiency in many of the conditions experienced. No significant increase of NOx is observed in any condition. The number of particles decreased up to 63% when engine works at 3000min−1 and 15% of maximum engine torque with hydrogen injection, in relation to the engine operating with commercial diesel. Moreover, the 25% of diesel fuel substitution by hydrogen causes a reduction in the maximum in-cylinder pressure, decreasing up to 16% at most demanding load condition (3000min−1 with 45% of maximum engine torque). This is due to the water generated during hydrogen oxidation, which absorbs heat to evaporate and cause a temperature and in-cylinder pressure decrease in the combustion process, that ensures the physical motor integrity.

Effects of the addition of oxygenated fuels as additives on combustion characteristics and particle number and size distribution emissions of a TDI diesel engine

The aim of the study is to evaluate the influence of the use of oxygenates as additives to diesel fuel on the combustion process, the specific fuel consumption, effective efficiency and emissions, especially particle emissions in the range 5.6–560nm in size distribution and number of a diesel engine. The oxygenate compounds used were EtilTerbutilEter (ETBE) and Diglyme which were added to Commercial Diesel (7% FAME). Engine bench tests were performed with 7 additive/CD blends in different proportions, 5%, 10% and 15% of oxygenated additive added to the base Commercial Diesel fuel. The tests were performed on a 2.0 TDI diesel engine VW Euro 4, in 9 stationary operating conditions (1500, 2250 and 3000min−1 to 15%, 30%, 45% load). Experimental results show that the mixing ratio additive/diesel is the parameter that has the greatest influence on the particle emission. NOx emission compared to CD increases or remains constant depending on the amount of additive in the mixture, engine speed and load condition. Furthermore, there is a dramatic decrease in the total particle concentration with the addition of oxygenated additives, especially when the ratio reaches 15%. The geometric mean diameter (GMD) of the particles of the blends, presents consistent trends with load and speed variation. Blends with 15% additive at all engine operating conditions are maintained in smaller sizes than the CD. The GMD does not show a clear dependence on the type of additive used, however the proportion of additive has significant influence on GMD. A higher proportion of additive, lower GMD.

RESEARCH INTO THE INFLUENCE OF TURBOCHARGER SYSTEM LEAKAGE ON THE PARAMETERS OF THE EXTERNAL WORK OF 1.9 TDI DIESEL ENGINE / TURBOKOMPRESORINĖS ORO PRIPŪTIMO SISTEMOS NESANDARUMO ĮTAKOS 1.9 TDI DYZELINIO VARIKLIO IŠORINIAMS DARBO PARAMETRAMS TYRIMAI

The article presents and analyses the comparable results of thestand tests of 1.9 TDI diesel engine. The purpose of the conductedresearch included solving a question of how losses in thecharge-air system impacted environmental and energy-economicalparameters in order to ensure the same load characteristicsof the diesel engine. The leakage factor was imitated by a holeof 3.1 mm in diameter, the size of which is possible in practice.Therefore, some significant negative changes were observed. Inall tested range of the loaded engine, a decrease of 6.7...7.8 %in charge pressure impacts an increase in greenhouse gas emissionsby 11...30 %. Fuel consumption increased by 11...14 %and difference in the deterioration of other indicators sometimesvaried compared with normal operating conditions. It was alsofound that, in a case of leakage, the electronic engine control unitinefficiently reduced the emission of the products of incompletecombustion in exhaust gases. Santrauka Straipsnyje pateikti dyzelinio variklio Audi 1.9 TDI palyginamieji stendinių tyrimų rezultatai bei jų analizė. Tyrimo tikslas buvo suformuotas autoriams iškėlus klausimą, kaip pripūtimo sistemos nesandarumas daro įtaką dyzelinio variklio ekonominiams-energetiniams ir ekologiniams rodikliams siekiant užtikrinti tas pačias apkrovos charakteristikas. Nesandarumo faktorių imituojant 3.1 mm skersmens anga, kurios dydis praktikoje realiai tikėtinas, buvo pastebėti reikšmingi neigiami pokyčiai. Kritus pripūtimo slėgiui 6,7–7,8 % šiltnamio dujų emisija tiriamajame variklio apkrovos diapazone išaugo 11–30 %, degalų sunaudojimas išaugo 11–14 %, kitų rodiklių pablogėjimas lyginant su įprastos eksploatacijos sąlygomis skyrėsi kartais. Nustatyta, jog esant nesandarumui variklio elektroninė valdymo sistema neefektyviai mažina nevisiško degimo produktų emisiją.

Effects of animal fat based biodiesel on a TDI diesel engine performance, combustion characteristics and particle number and size distribution emissions

The aim of the study is to evaluate the influence of the animal fat based biodiesel/diesel fuel blends in comparison with pure diesel and soybean biodiesel blends over the engine performance, the specific fuel consumption and emissions, especially on particle emissions in size (5.6–560nm) and number distribution of a diesel engine. Tests were conducted in engine test bench with 6 animals fat based blends of animal fat based biodiesel/diesel and soybean biodiesel/diesel in different proportions B10 (10% biodiesel and 90% pure diesel fuel), B20, B25, B30, B40, B50 and D100 (pure diesel). Tests were performed on a Euro 4 diesel engine, following an Urban Driving Cycle and 5 stationary operating conditions (15, 30, 50, 70 and 100km/h). Experimental results show that the ratio of the blend biodiesel/diesel, followed by the saturation level of biodiesel, is the parameter that most influence has on the emission of pollutants. The nitrogen oxides emission increases compared to pure diesel and particle number emission decreases significantly, especially when the concentration of biodiesel is greater than 25%. The geometric mean diameter of the particles from biodiesel presents trends consistent with the load and speed variation and has no dependence on the type of biofuel used and is always less than those measured for mineral diesels. In all engine operating conditions, it was observed that particle emissions from the combustion of animal fat based biodiesel with a percentage higher than 40%, are emitted in smaller quantities than with the same proportions of soybeans.

Numerical Analysis of Biogas Composition Effects on Combustion Parameters and Emissions in Biogas Fueled HCCI Engines for Power Generation

This study investigates the effects of biogas composition on combustion stability for a purely biogas fueled homogeneous charge compression ignition (HCCI) engine. Biogas is one of the most promising renewable fuels for combined heat and power systems driven by internal combustion engines. However, the high content of CO2 in biogas composition leads to low thermal efficiencies in spark ignited and dual fuel compression ignited engines. The study is divided into two parts: First experimental results on a biogas-fueled HCCI engine are used to illustrate the effects of intake conditions on combustion stability, and second a simulation methodology is used to investigate how biogas composition impacts combustion stability at constant intake conditions. Experimental analysis of a four cylinder, 1.9 L Volkswagen TDI diesel engine shows that biogas-HCCI combustion exhibits high gross indicated mean effective pressure (close to 8 bar), high gross indicated efficiency (close to 45%), and ultralow NOx emissions below the US2010 limit (0.27 g/kWh). An inlet absolute pressure of 2 bar and inlet temperature of 473 K (200 °C) were required for allowing HCCI combustion with a biogas composition of 60% CH4 and 40% CO2 on a volumetric basis. However, slight changes in inlet pressure and temperature caused large changes in cycle-to-cycle variations at low equivalence ratios and large changes in ringing intensity at high equivalence ratios. Numerical analysis of biogas-HCCI combustion is carried out with a sequential methodology that includes one-zone model simulations, computational fluid dynamics (CFD) analysis, and 12-zones model simulations. Numerical results for varied biogas composition show that at high load limit, higher contents of CH4 in biogas composition allow advanced combustion and increased burning rates of the biogas air mixture. Higher contents of CO2 in biogas composition allow lowered ringing intensities with moderate decrease in the indicated efficiency and power output. NOx emissions are not highly affected by biogas composition, while CO and unburned hydrocarbons (HC) emissions tend to increase with higher contents of CO2. According with the numerical results, biogas composition is an effective strategy to control the onset of combustion and combustion phasing of HCCI engines running biogas, allowing more stabilized combustion at low equivalence ratios and safe operation at high equivalence ratios. The main advantages of using biogas-fueled HCCI engines in CHP systems are the low sensitivity of power output and indicated efficiency to biogas composition, as well as the ultralow NOx emissions achieved for all tested compositions.

Exploring Strategies for Reducing High Intake Temperature Requirements and Allowing Optimal Operational Conditions in a Biogas Fueled HCCI Engine for Power Generation

This paper evaluates strategies for reducing the intake temperature requirement for igniting biogas in homogeneous charge compression ignition (HCCI) engines. The HCCI combustion is a promising technology for stationary power generation using renewable fuels in combustion engines. Combustion of biogas in HCCI engines allows high thermal efficiency similar to diesel engines, with low net CO2 and low NOx emissions. However, in order to ensure the occurrence of autoignition in purely biogas fueled HCCI engines, a high inlet temperature is needed. This paper presents experimental and numerical results. First, the experimental analysis on a 4 cylinder, 1.9 L Volkswagen TDI diesel engine running with biogas in the HCCI mode shows high gross indicated mean effective pressure (close to 8 bar), high gross indicated efficiency (close to 45%) and NOx emissions below the 2010 US limit (0.27 g/kWh). Stable HCCI operation is experimentally demonstrated with a biogas composition of 60% CH4 and 40% CO2 on a volumetric basis, inlet pressures of 2–2.2 bar (absolute), and inlet temperatures of 200–210 °C for equivalence ratios between 0.19–0.29. At lower equivalence ratios, slight changes in the inlet pressure and temperature caused large changes in cycle-to-cycle variations, while at higher equivalence ratios these same small pressure and temperature variations caused large changes to the ringing intensity. Second, numerical simulations have been carried out to evaluate the effectiveness of high boost pressures and high compression ratios for reducing the inlet temperature requirements while attaining safe operation and high power output. The one zone model in Chemkin was used to evaluate the ignition timing and peak cylinder pressures with variations in temperatures at intake valve close (IVC) from 373 to 473 K. In-cylinder temperature profiles between IVC and ignition were computed using Fluent 6.3 and fed into the multizone model in Chemkin to study combustion parameters. According to the numerical results, the use of both higher boost pressures and higher compression ratios permit lower inlet temperatures within the safe limits experimentally observed and allow higher power output. However, the range of inlet temperatures allowing safe and efficient operation using these strategies is very narrow, and precise inlet temperature control is needed to ensure the best results.

Experimental study of biogas combustion in an HCCI engine for power generation with high indicated efficiency and ultra-low NO x emissions

Combustion parameters and the main exhaust emissions from a biogas fueled HCCI engine are investigated in this study. The study was conducted on a 4-cylinder, 1.9L Volkswagen TDI Diesel engine, which was modified to run in HCCI mode with biogas by means of inlet charge temperature control, boosted intake pressure, and a sonic flow device upstream of the inlet manifold to control biogas composition and the equivalence ratio. For simulating typical power generation conditions, the engine was coupled to an AC motor generator operating at 1800 rpm. In the startup process, gasoline was used in HCCI mode for all cylinders. During the tests, biogas was used in cylinders 2 and 3, and gasoline was used in cylinders 1 and 4 to allow for more stable engine coolant and oil temperatures. The tests were performed through an experimental factorial design to evaluate the effect of inlet charge temperature, boost pressures, and the equivalence ratio of the biogas–air mixture on HCCI combustion parameters and emissions. For biogas at lower equivalence ratios, slight increases in inlet charge temperature and boost pressures enhanced combustion parameters and reduced CO and HC emissions. For biogas at higher equivalence ratios, the effects of inlet charge conditions on HCCI combustion and CO and HC emissions were attenuated; however, ringing intensities and NO x emissions were increased with higher inlet charge temperature and higher boosted pressures. The maximum gross indicated mean effective pressure was 7.4 bar, the maximum gross indicated efficiency was close to 45%, and NO x emissions were below the US-2010 limit of 0.27 g/kW h. These results show that a biogas fueled HCCI engine is a promising option in stationary power generation applications, meeting high efficiency and ultra-low NO x emissions.

Comparison of fuel economies of high efficiency diesel and hydrogen engines powering a compact car with a flywheel based kinetic energy recovery systems

Coupling of small turbocharged high efficiency diesel engines with flywheel based kinetic energy recovery systems is the best option now available to reduce fuel energy usage and reduce green house gas (GHG) emissions. The paper describes engine and vehicle models to generate engine brake specific fuel consumption maps and compute vehicle fuel economies over driving cycles, and applies these models to evaluate the benefits of a H 2ICEs developed with the direct injection jet ignition engine concept to further reduce the fuel energy usage of a compact car equipped with a with a flywheel based kinetic energy recovery systems. The car equipped with a 1.2 L TDI Diesel engine and KERS consumes 25 g/km of fuel producing 79.2 g/km of CO 2 using 1.09 MJ/km of fuel energy. These CO 2 and fuel energy values are more than 10% better than those of today’s best hybrid electric vehicle. The car equipped with a 1.6 L DI-JI H 2ICE engine consumes 8.3 g/km of fuel, corresponding to only 0.99 MJ/km of fuel energy.

The new pickup VW Amarok

With the Amarok, Volkswagen Commercial Vehicles is launching one of the most modern pickup trucks in the world onto the market. No competitor in its class is as economical. Many of the technologies implemented in the Amarok are being used for the first time in this segment. These include bi-turbocharging for the top version of the TDI diesel engine with 120 kW (163 PS) power. The 5254 mm long vehicle in ladder frame concept is available with rear-wheel drive as well as non-permanently and permanently four-wheel drive.

The Second generation of the VW Polo BlueMotion

The VW Polo BlueMotion from 2006 is in the line with the reigning fuel economy champion, like the Lupo 3L TDI. Now, within just under one year after the successful market launch of the new Polo, Volkswagen presents the second generation of the Polo BlueMotion. It achieves a good drag coefficient of 0.307, a new 1.2-l TDI diesel engine with common-rail injection and a start/stop system which reduce the fuel consumption and CO2 emissions in urban traffic as well as in stop-and-go phases by up to 6 % on average and the noise emissions when stationary to zero.

Detecting Air Leaks in an Engine Intake Manifold Using Nonlinear PCA

This paper describes the application of nonlinear principal component analysis (NLPCA) for the detection of air leaks in the intake manifold of internal combustion engines. Such faults, if undetected, can lead to inefficient engine operation, result in expensive repairs and cause an increased level of exhaust emissions. Using a VW 1.9L TDI diesel engine, several data sets were recorded that describe normal steady-state behaviour and the influence of air leaks at various speed and pedal positions. These data sets were then analysed using an NLPCA based monitoring scheme. It was found that even small air leaks could be detected.

Effect of Oxygenated Fuel on Combustion and Emissions in a Light-Duty Turbo Diesel Engine

In previous studies on a single-cylinder IDI diesel engine and a V-8 DI turbo diesel engine, significant reductions in particulate matter emissions were observed with the blends of glycol ethers in diesel fuel. In this study, experiments on the effects of oxygenated fuels on emissions and combustion were performed in a 4-cylinder TDI diesel engine. A blend of 20 wt % monoglyme and 80 wt % diglyme, referred to as CETANER, has been examined as a diesel reformulating agent. Blend ratios were considered to provide approximately 2, 4, and 6 wt % oxygen to low-sulfur diesel fuel. Gaseous and particulate emission measurements, as well as heat release rate analysis, have been used to address how emissions and combustion scale with increasing weight percent oxygen in the fuel. The results demonstrate that the oxygenated fuel provides significant reduction in particulate matter with a small penalty on NOx emission, especially at high load. This oxygenated fuel effect may result from an enhanced concentration of oxygen atoms in the over-rich mixture thereby contributing to soot suppression and thermal NOx formation through a shift to a leaner mixture. Low load results imply that the combined effect of relatively high exhaust gas recirculation (EGR) ratio and oxygen addition contributes to both NOx and soot reduction through a combination of flame temperature decrease and suppression of soot precursors. The combined effects on thermal NOx reduction at low load appear to be confirmed by heat release analysis, which indicates a small reduction in premixed burn peak and in-cylinder pressure. The slight reduction in HC and CO emissions under most conditions indicates an improvement of combustion efficiency with the use of oxygen addition. This result also represents the potential of diesel reformulation coupled with high EGR ratio for a better particulate/NOx tradeoff. Particulate morphology, as seen in transmission electron microscopy (TEM) micrographs, shows that enhanced oxidation of unburned hydrocarbon due to oxygen addition leaves a less agglomerated particulate structure especially at low mode, leading to a higher number density of smaller particles and a lower particulate mass.