Commercial Diesel Engine Research Articles

Atmospheric impacts of black carbon emission reductions through the strategic use of biodiesel in California

The use of biodiesel as a replacement for petroleum-based diesel fuel has gained interest as a strategy for greenhouse gas emission reductions, energy security, and economic advantage. Biodiesel adoption may also reduce particulate elemental carbon (EC) emissions from conventional diesel engines that are not equipped with after-treatment devices. This study examines the impact of biodiesel blends on EC emissions from a commercial off-road diesel engine and simulates the potential public health benefits and climate benefits.EC emissions from the commercial off-road engine decreased by 76% when ultra-low sulfur commercial diesel (ULSD) fuel was replaced by biodiesel. Model calculations predict that reduced EC emissions translate directly into reduced EC concentrations in the atmosphere, but the concentration of secondary particulate matter was not directly affected by this fuel change. Redistribution of secondary particulate matter components to particles emitted from other sources did change the size distribution and therefore deposition rates of those components. Modification of meteorological variables such as water content and temperature influenced secondary particulate matter formation.Simulations with a source-oriented WRF/Chem model (SOWC) for a severe air pollution episode in California that adopted 75% biodiesel blended with ULSD in all non-road diesel engines reduced surface EC concentrations by up to 50% but changed nitrate and total PM2.5 mass concentrations by less than ±5%. These changes in concentrations will have public health benefits but did not significantly affect radiative forcing at the top of the atmosphere. The removal of EC due to the adoption of biodiesel produced larger coatings of secondary particulate matter on other atmospheric particles containing residual EC leading to enhanced absorption associated with those particles. The net effect was a minor change in atmospheric optical properties despite a large change in atmospheric EC concentrations. These results emphasize the importance of considering EC mixing state in climate research.

Analysis of Pollutant Emissions of Diesel Engine Operating with Mixture of Diesel, Biodiesel and Natural Gas

The aim of this research is to study the pollutant emissions of the commercial diesel engine, operating with B5 (commercial diesel), B70, B80, B90 and natural gas. The fuel used in the engine consists of a mixture of 15% diesel and biodiesel (liquid fuel) and 85% natural gas. Experiments were made using 40, 60 and 80 kW load. The engine was instrumented to obtain the temperature, air, gas and diesel (plus biodiesel) flow rates, the air pressure at the entrance of the engine, the lubricant oil temperature, and the concentration of exhaust gases during each experimental test. It was verified that the emission of NOx, NO and CO2 had decreased while the emissions of CO and SO2 had increased, when compared to the conditions using standard diesel (B5) alone.

EFFECT OF AMBIENT TEMPERATURE ON DIESEL-ENGINE COMBUSTION CHARACTERISTICs OPERATING WITH ALCOHOL FUEL

Biofuel is an alternative fuel source for diesel engines. Nowadays, biofuel attracts more interest due to the depletion of mineral petroleum resources. The aim of this paper is to study the effect of ambient temperature on the combustion and performance of a diesel engine when using ethanol and methanol as fuels. The one-dimensional numerical analysis uses the GT-Power software program to simulate a commercial four-cylinder diesel engine. The diesel engine was simulated in order to study the characteristics of engine combustion when the engine is operating with ethanol and methanol as alternative fuels. The simulations were conducted under the full-load condition for an engine operating with diesel, ethanol, and methanol. Ambient temperatures used for each test were 30, 40, and 50 °C. The results show that the in-cylinder pressure for ethanol is higher than that of methanol and diesel at different ambient temperatures, while methanol was found to yield a higher rate of heat release compared to ethanol and diesel. However, changes in ambient temperature in the inlet pipe do not affect the rate of heat release when using any fuel. It can be concluded that biofuels are excellent fuel alternatives to replace diesel in the future. Keyword: Ambient temperature; diesel engine; ethanol, methanol; in-cylinder pressure.

디젤-워터 에멀젼 연료의 조성에 따른 분무 특성에 관한 연구

Using Diesel-Water Emulsion fuel in commercial diesel engine can reduce NOx and soot when it is injected through the injector. Because water in Diesel-Water Emulsion fuel is vaporized ahead of diesel particle and it cause decrease of combustion temperature. Furthermore, research about the possibility of applicating Diesel-Water Emulsion fuels to commercial diesel engine is demanded in order to prove that Diesel-Water Emulsion fuel is able to apply commercial diesel engine without any replacement of equipments. This research analyzed applicable possibility of Diesel-Water Emulsion fuels to commercial diesel engine’s fuel injection system refering injection and spray characteristics. In this research, there are 3 experiments, that is injection quantity, spray visualization, and injection rate. Diesel-Water Emulsion fuel has less injection quantities compared to diesel fuel, and spray penetration length is more longer than diesel. Furthermore, emulsion fuels have less dispersed than diesel fuel. In conclusion, comparing with diesel fuel with only spray characteristics, Diesel-Water Emulsion fuel has bad effects about dispersion and vaporization.

G0700402 大型車両用DPF内部の広範囲逐次観察による圧力損失急上昇現象発現要因の分析

As a way of reducing the amount of Paniculate Matter (PM) contained in the exhaust gas, Diesel Particulate filter (DPF) is widely used. To maintain the condition of DPF normal and effective, estimation of the amount of PM deposit accumulated in DPF is very important. Occasionally, the value of pressure drop rises suddenly and it leads to overestimation of the amount of PM deposit. The behavior of PM deposit layer, while the value of pressure drop is increasing, is still unclear. In this paper, we reproduce the sudden pressure increase phenomenon using a commercial diesel engine and a DPF. Several conditions are found to be indispensable to reproduce the phenomenon. The authors also have developed a visualization method to realize the wide-perspective internal observation of DPF. Under the engine operating condition that causes the sudden pressure increase phenomenon, the wide-perspective internal observation experiment has been conducted to clarify the behavior of PM deposit layers in DPF. Off-line experimental result: the image of the DPF observation surface taken after the experiment, indicates that the PM deposit layers have collapsed darling the experiment.

Exploring Fuel-Saving Potential of Long-Haul Truck Hybridization

Comparisons are reported on the simulated fuel economy for parallel, series, and dual-mode hybrid electric long-haul trucks, in addition to a conventional powertrain configuration, powered by a commercial 2010-compliant 15-L diesel engine over a freeway-dominated heavy-duty truck driving cycle. The driving cycle was obtained by measurement during normal driving conditions. The results indicated that both parallel and dual-mode hybrid powertrains were capable of improving fuel economy by 7% to 8%. However, there was no significant fuel economy benefit for the series hybrid truck because of internal inefficiencies in energy exchange. When reduced aerodynamic drag and tire rolling resistance were combined with hybridization, there was a synergistic fuel economy benefit for appropriate hybrids that increased the fuel economy benefit to more than 15%. Long-haul hybrid trucks with reduced aerodynamic drag and rolling resistance offered lower peak engine loads, better kinetic energy recovery, and reduced average engine power demand. Thus, it is expected that hybridization with load reduction technologies offers important potential fuel energy savings for future long-haul trucks.

Soot Reactivity at commercial Vehicle Diesel Engines

Soot Reactivity at commercial Vehicle Diesel Engines

One-Dimensional Simulation of the Combustion Process in an Engine Cylinder with Ethanol

The diesel engine is one of the most important engines for road vehicles. The engine nowadays operates with different kinds of alternative fuels, such as natural gas and biofuel. The aim of this article is to study the combustion process that occurs in an engine cylinder of a diesel engine when using biofuel. The one-dimensional numerical analysis using GT-Power software is used to simulate the commercial four-cylinder diesel engine. The engine operated at high engine load and speed. The ethanol fuel used in the simulation is derived from the conventional ethanol fuel properties. The analysis of simulations includes the cylinder pressure, combustion temperature and rate of heat release. The simulation results show that in-cylinder pressure and temperature for ethanol is higher than for diesel at any engine speed. However, the mass fraction of ethanol burned is similar to that of diesel. MFB only affects the engine speed.

바이오디젤 연료 분무의 거동특성 연구

Diesel engine is most suitable one for biodiesel fuel because the compression-ignition diesel engine has desirable fuel consumption due to higher thermal efficiency and in addition, the improvement of the fuel consumption also leads to a reduction of <TEX>$CO_2$</TEX> emission and then it does not need to have spark-ignition system, which means that there is less charge on the technic and complexity. In this study, the spray behavior characteristics of the vegetable palm oil were analyzed by using a common-rail injection system of commercial diesel engine and the results were compared with those obtained for the diesel fuel. The injection pressures and blend ratios of palm oil and diesel(BD3, BD5, BD20, BD30, BD50, and BD100) were the main parameters. The experiments were conducted for different injection pressures: 500bar, 1000bar, 1500bar, and 1600bar by setting injection duration to <TEX>$500{\mu}s$</TEX>. Consequently, it was found that there is no significant difference in the macro characteristics of the spray behavior(spray penetration and spray angle) in response to change in the blend ratio of palm oil and diesel at a fixed injection pressure. In particular, all experiments showed the spray angle about <TEX>$12^{\circ}{\sim}13^{\circ}$</TEX>.

Analysis of Aluminum and Steel Pistons—Comparison of Friction, Piston Temperature, and Combustion

While steel pistons have been in use for a long time in commercial vehicle diesel engines, the first series production applications for passenger car diesel engines are currently imminent. The main reason for the use of steel pistons in high speed diesel engines is not, as maybe initially hypothesized, the increasing requirements on the component strength due to increasing mechanical loads, but rather challenges based on the actual CO2-legislation. The increasing requirements to reduce the fuel consumption necessitate new innovative technologies. The imminent penalties for exceeding the prescribed CO2 emissions seem to make the steel piston a viable alternative today, despite its higher manufacturing costs. So far, the CO2-benefits using steel pistons were mainly ascribed to the reduced friction between piston and cylinder liner due to no thermal interference.

Soot Reactivity at Commercial Vehicle Diesel Engines

Soot Reactivity at Commercial Vehicle Diesel Engines

Current Understanding of Cu-Exchanged Chabazite Molecular Sieves for Use as Commercial Diesel Engine DeNOx Catalysts

Selective catalytic reduction (SCR) of NOx with ammonia using metal-exchanged molecular sieves with a chabazite structure has recently been commercialized on diesel vehicles. One of the commercialized catalysts, i.e., Cu-SSZ-13, has received much attention for both practical and fundamental studies. For the latter, the particularly well-defined structure of this zeolite is allowing long-standing issues of the catalytically active site for SCR in metal-exchanged zeolites to be addressed. In this review, recent progress is summarized with a focus on two areas. First, the technical significance of Cu-SSZ-13 as compared to other Cu ion-exchanged zeolites (e.g., Cu-ZSM-5 and Cu-beta) is highlighted. Specifically, the much enhanced hydrothermal stability for Cu-SSZ-13 compared to other zeolite catalysts is addressed via performance measurements and catalyst characterization using several techniques. The enhanced stability of Cu-SSZ-13 is rationalized in terms of the unique small pore structure of this zeolite catalyst. Second, the fundamentals of the catalytically active center; i.e., the chemical nature and locations within the SSZ-13 framework are presented with an emphasis on understanding structure–function relationships. For the SCR reaction, traditional kinetic studies are complicated by intra-crystalline diffusion limitations. However, a major side reaction, nonselective ammonia oxidation by oxygen, does not suffer from mass-transfer limitations at relatively low temperatures due to significantly lower reaction rates. This allows structure–function relationships that are rather well understood in terms of Cu ion locations and redox properties. Finally, some aspects of the SCR reaction mechanism are addressed on the basis of in situ spectroscopic studies.

바이오연료의 디젤엔진 적용에 관한 실험연구

Compared to gasoline engines, diesel engines with a relatively simple ignition system are more advantageous in the application of biodeisel fuel to engine. Then in this study the comparative analysis on the spray characteristics and combustion emissions characteristic between the biodiesel(soybean oil) and diesel, the fuel for commercial diesel engine, was performed with common rail injection system. Injection pressure and ratio of biodiesel blended fuel were selected as main experimental variables. Consequently, it can be found that there is no significant difference in the macro characteristics of the spray behavior(spray penetration and spray angle) in response to change in the blend ratio of soybean oil and diesel at a fixed injection pressure, in particular, soot creation in combustion emissions in the region of low pressure was greatly affected by the blend ratio of soybean oil, however, the creation in the region of high pressure was almost unaffected by the blend ratio because of promoted atomization.

Classification and individualization of used engine oils using elemental composition and discriminant analysis

The six most common commercial automotive gasoline and diesel engine oils in the Republic of Korea, ZIC A, ZIC XQ RV/SUV, Kixx G1, Kixx RV, and the brand name products HD Premium gasoline and HD Premium diesel, were randomly used in nineteen different vehicles. Samples of seventy-six used engine oils, which were withdrawn from the sumps of those vehicles at different intervals, were analyzed using inductively coupled plasma-optical emission spectrometry (ICP-OES), and statistically compared. Two data analysis strategies were used to interpret and understand the elemental profiles in the multi-dimensional data. Macro (additive elements of Ca, Zn and P) and trace (wear metal elements of Ag, Al, Ba, Cd, Cr, Cu, Fe, Mg, Mo, Na, Ni, Pb and Sn) elements were used as potential markers to determine the brand of oil used and the engine type in which the oil was used, and to trace the individual vehicle for forensic purposes. The discriminant analysis statistical technique was applied, and its prediction ability was assessed. In this study, 92.1%, 82.9% and 92.1% of the cross-validated grouped cases correctly predicted the brand of oil, the engine type and the vehicle that was the source of the oil, respectively.

Simultaneous Air Fraction and Low-Pressure EGR Mass Flow Rate Estimation for Diesel Engines

This paper describes a low-pressure exhaust gas recirculation (LP-EGR) mass flow rate estimation method and a robust air mass fraction observer for a Diesel engine with dual-loop EGR system. Both observers operate simultaneously eliminating the need for pressure measurement upstream the LP-EGR valve. A sliding mode observer is designed to estimate the LP-EGR mass flow rate using the standard sensors available in commercial Diesel engines. A robust linear parameter varying Kalman filter is designed for the air mass fraction estimation. The convergence and robustness of the observers are ensured by means of Lyapunov stability and a linear matrix inequality (LMI) framework for the sliding mode observer and robust Kalman filter, respectively. The observers are evaluated with a Motor Vehicle Emission Group (NMVEG) cycle using an engine model validated on an experimental benchmark as a reference.

Control oriented air path model for compressed air boosted Diesel engines

In this paper an air path model of a diesel engine is presented for control system design. The model was developed for common-rail, direct injected, turbocharged and intercooled commercial vehicle diesel engines which are equipped with compressed air booster system (PBS® – Pneumatic Booster System)[12], high pressure exhaust gas recirculation loop (EGR) with EGR-cooler and exhaust brake (EB). In current and next generation emission standards and legislation introduced significant limitations for NOx and soot. It is really challenging to handle these components, especially at transient engine operations. Additionally the fuel economy and driveability requirements also have to be fulfilled. It is widely known that the nitric oxide formation can be limited with an appropriate amount of exhaust gas recirculation. It can be achieved even in transient modes with precisely controlled EGR-valve operation and with a suitable backpressure generation by the exhaust brake. The soot formation is influenced mainly by the air-fuel ratio of the mixture which can be affected by the intake manifold pressure in case of a desired engine load and EGR rate. With the compressed air booster system the intake manifold pressure can be controlled in transients arbitrarily. Therefore with a suitable air path controller the modeled engine setup is able to handle both the NOx and soot formation in transient cases. To solve the presented control problem a model based controller design is targeted. The reported model is the first step of this work.

English

Palm oil is one of the vegetable oil, which is converted to biodiesel through a transesterification process using methanol as the catalyst. Palm oil biodiesel or palm methyl ester (PME) can be used in diesel engines without any modification, and can be blended with conventional diesel to produce different proportions of PME-diesel blend fuels. The physical properties of PME were evaluated experimentally and theoretically. The effect of using neat PME as fuel on engine performance and emissions was evaluated using a commercial four-cylinder four-stroke IDI diesel engine. The experimental results on an engine operated with PME exhibited higher brake specific fuel consumption in comparison with the conventional fuel. With respect to the incylinder pressure and heat release rate, these increased features by over 8.11% and 9.3% with PME compared to conventional diesel. The overall results show that PME surpassed the diesel combustion quality due to its psychochemical properties and higher oxygen content.

바이오연료의 엔진 적용을 위한 분무거동 기초연구(팜유-점성고려)

디젤엔진은 바이오연료 적용을 위한 엔진으로서 가솔린엔진과 비교해 사용연료가 바이오연료와 유사한 높은 세탄가를 가지며, 가솔린엔진과 달리 점화계통 장치의 불필요 등 기존 엔진의 개조비용 등에서 유리한 장점이 있다. 따라서 본 연구에서는 상용 디젤 엔진의 커먼레일 분사시스템을 사용하여 바이오연료인 식물성 팜유의 분무거동특성을 해석하고, 그 결과를 기존의 디젤엔진 연료인 경유와 비교?분석하였다. 실험변수로서는 분사압력과 경유에 대한 바이오디젤 연료의 혼합비율(BD3, BD5, BD20, BD30, BD50, BD100)을 달리하였다. 분사압력은 500bar, 1000bar, 1500bar 및 1600bar로 설정하고 분사기간은 500μs로 동일하게 하였다. 본 연구의 결과로서, 분사압력이 동일한 경우 사용한 바이오디젤 연료의 혼합비 변화에 대한 거시적 분무거동특성(분무선단도달거리 및 분무각)의 변화는 뚜렷하지 않았다. 특히 분무각의 경우 본 연구의 모든 실험조건에 있어서 약 15°의 값을 나타내었다.

Performance improvements in a longer-stroke, spark-ignition gas engine

The engine performance with several stroke/cylinder diameter (S/D) ratios from 1.0 to 2.0 was investigated in a small spark-ignition gas engine by experiments and with computational fluid dynamics (CFD) engine analysis. The experiments were conducted on a specially manufactured, single-cylinder, spark-ignition gas engine with the cylinder head of a commercial diesel engine with a spark plug instead of a fuel injector. The cylinder diameter was fixed at 70 mm, the same as the original engine, and the stroke length was varied at 70 mm (S/D = 1.0), 105 mm (S/D = 1.5), and 140 mm (S/D = 2.0) under the same compression ratio of 12:1 by changing the piston, the cylinder liner, the cylinder block, the crankshaft, and the connecting rod. The engine speed was set at 1200 r/min, and the test fuel was commercial compressed natural gas provided from a bottle. The indicated thermal efficiency improved significantly with S/D ratio, mainly due to the reductions in cooling loss, maintaining the degree of constant-volume heat release at high levels, and also due to improvements in the combustion efficiency. The optimum S/D ratio is about 1.5, as the improvement in indicated thermal efficiency with increase of S/D from 1.0 to 1.5 was more significant than that with S/D increase from 1.5 to 2.0. The indicated mean effective pressure (IMEP) with S/D = 1.5 was the largest among these S/D ratios, and the IMEP with S/D = 2.0 was much smaller due to lower volumetric efficiency. The indicated thermal efficiency improved with longer strokes in the stoichiometric and lean conditions of excess air ratios below 1.5, but the deterioration in thermal efficiency with leaner conditions, above 1.5, was more pronounced with longer strokes. The CFD analysis also showed the improvement in thermal efficiency with longer strokes, and the indicated thermal efficiency improved more in the case of the same cylinder diameter than in the case of the same displacement volume. This is mainly due to the larger reduction in cooling loss in the case with the same cylinder diameter. However, even with the same displacement volume, the reduction in cooling loss and the improvement in indicated thermal efficiency with longer strokes were reliably obtained. The experimental equations for the heat transfer coefficient with mean piston speed, including Woschni’s equation, do not express the change in heat transfer at the higher S/D ratios.

Biodiesel Emissions from a Baseline Engine Operated with Different Injection Systems and Exhaust Gas Recirculation (EGR) Strategies during Transient Sequences

This work is focused on the measurement and analysis of biodiesel emissions resulting from two commercial diesel engines derived from the same baseline engine. One of the engines was equipped with a rotary fuel injection pump electronically controlled. Another engine was equipped with a common-rail injection system. Both engines were tuned by the manufacturer with diesel fuel, and each of them was optimized with different exhaust gas recirculation (EGR) strategies. Both engines were tested under several transient conditions. A methyl ester obtained from unused sunflower oil was tested as diesel fuel, pure and blended with 30 and 70% of a commercial diesel fuel, which was also used pure. The engines were mounted in a test bench prepared for operating under transient conditions. An AVL 439 smoke meter and an Environnement gas analyzer allowed for the study of the effect of these fuels on the variations of the engine emissions with time. The consideration of the thermochemical properties of the tested fuels and the engine parameters, such as fuel/air ratio or EGR ratio, were used for the analysis of the results. The studied engine transient processes were (a) a load increase at constant engine speed and (b) an engine speed decrease at constant torque. The obtained results proved that the biodiesel effect on pollutant emissions during transient conditions depends upon the fuel injection system and EGR strategy used during the engine tuning.