High Pressure Common Rail Diesel Research Articles

Effects of gasoline and iso-butanol addition on combustion and pollutant emissions of a common-rail diesel engine at different injection timing

Combustion and pollutant emissions from a high pressure common-rail diesel engine using ternary diesel/gasoline/iso-butanol blends were investigated experimentally in order to improve combustion process and farther decrease emissions of diesel/gasoline blends. The experiments were carried out at five injection timings under medium engine load. Four fuels were tested in this work, D100 (pure diesel) was tested for baseline comparison, the other three fuels were DG (30% gasoline in diesel fuel by mass), DGB (15% gasoline and 15% iso-butanol in diesel fuel) and DB (30% iso-butanol in diesel fuel). Experimental results indicate that DG, DGB and DB delayed the ignition timing periods and shortened the combustion durations, resulting in higher levels of premixed combustion and maximum pressure rise rates (MPRRs). Meanwhile, DGB and DB showed higher brake thermal efficiencies (BTEs) than DG and D100. It was also found that adding gasoline and iso-butanol, substantial decrease in carbon monoxide (CO) emissions, particulate diameters, nucleation mode (NM) and accumulation mode (AM) particle numbers were achieved, but the emissions of unburned hydrocarbons (HC) and nitrogen oxides (NOx) were increased slightly. DGB and DB produced better NOx-particulate matter (PM) trade-off than DG and D100 in combination with retarded injection timing. Furthermore, PM emitted from blend fuels showed higher ratios of sub-10 nm particle number concentrations, the sequence is D100 < DG < DGB < DB, which may be more harmful to human health.

Effects of 2,5-dimethylfuran addition on morphology, nanostructure and oxidation reactivity of diesel exhaust particles

As an oxygenated additive, 2, 5-dimethylfuran (DMF) addition is a method to reduce effectively the diesel particulate matter (PM) emissions. However, the influences of DMF addition on oxidation behavior and nanostructure of PM produced from diesel engines are not well understood. This study explores the effects of DMF addition on morphology, nanostructure and oxidation reactivity of diesel exhaust particles. Experiments were conducted in a high pressure common-rail diesel engine fueled with pure diesel, DMF10 (90% diesel and 10% DMF, by vol.), DMF20 (80% diesel and 20% DMF, by vol.), under two different engine loads at the same engine speed (1800 r/min). Particulate samples were collected from engine exhaust tailpipe and further characterized by transmission electron microscope (TEM), Raman spectroscopy (RS) and thermogravimetric analysis (TGA). Results showed that the physicochemical features of diesel exhaust particles can be influenced by both engine load and DMF blending ratio. Under the given engine load condition, soot particle from DMF20 was more reactive to oxidation, followed by samples from DMF10 and diesel. With a rise of DMF blending ratio, both primary particle diameter and fringe length decreased while fringe tortuosity increased. Similar with the results obtained by TEM, the larger D1-FWHM and ID1/IG for blended fuels demonstrated less graphitic structure. Specially, the fringe separation distance and AD1/AG did not show statistically significant differences between various tested fuels in this study. The more disordered structures explained the higher reactivity of soot from blended fuels. Independently of tested fuel, soot particles exhibited larger primary particle diameter and more graphitic structure under higher engine loads, indicating a lower soot oxidation reactivity.

Simulation of the Effect of Fuel Injection Rate that Matches Fuel Injection Advanced Angle on the Performance of Ultra High Pressure Common Rail Diesel Engine

On the basis of introducing the implementation method of variable fuel injection rate, the calculation model of a single-cylinder ultra high pressure common rail diesel engine was built, and the accuracy of this model was verified with experiments; then the effects of different fuel injection rates and fuel injection advanced angles on the performance of the ultra high pressure common rail diesel engine were analyzed with this model. The results show that the variable fuel injection rate can be realized by adjusting the opening time of electric-controlled pressure amplifier and injector solenoid valve in the ultra high pressure common rail system. With the lagging of pressurization time, the cylinder pressure, cylinder temperature, heat release rate and NOx emissions of the diesel engine decrease, while the soot emission rises. The ultra high pressure rectangle injection rate can make the diesel engine acquire best power and economy performance. With the increasing of fuel injection advanced angle, the cylinder pressure, cylinder temperature, heat release rate and NOx emission of the diesel engine rise, while the soot emission decreases first and then rises, the too small or too large fuel injection advanced angle can both reduce the power and economy performance of the diesel engine. The high fuel injection rate that matches small fuel injection advanced angle can improve power output and reduce fuel consumption of the diesel engine, and there is an optimal fuel injection advanced angle for each fuel injection rate to make the diesel engine performance achieve the best.

Study on the effect of piston skirt profile on the vibration behavior of non-road high pressure common rail diesel engine

The piston secondary motion is the most predominant excitation source for the mechanical vibration of diesel engine, which is directly affected by the piston profile. The effects of piston skirt profile on the dynamic behavior of piston and the vibration characteristics of engine block is studied synthetically by the method of a combination of experimental test and numerical simulation. The temperature distribution of the piston top surface under rated working condition is tested by a hardness plug, which is used as the boundary condition to carry out the thermodynamic simulation of diesel engine working process, to obtain the hot profile of the piston. Then, the dynamics model of piston assemblies are formally established, and the skirt profiles of different bump positions of the piston skirt are optimally designed. Based on the above analysis, a comprehensive study on the influence of bump position on the piston dynamic behavior is carried out. Then, applying the modal testing method for the engine block and crankshaft to establish the elastic multi-body dynamics model of diesel engine and load the piston slapping force at different bump positions, the vibration response of the surface structure under the action of different piston slapping forces is also studied. The results show that the mechanical vibration of engine block will become more severe with the hiking up of bump position at the piston skirt. Also, the vibration behavior of the engine block in the middle and high frequency section is very sensitive to the bump position of the piston skirt, especially in the frequency range of 1600 Hz–3150 Hz. In addition, vibration noise performance can be significantly improved by adjusting the bump position of piston skirt downwards. Particularly, the vibration noise performance can be best achieved when the bump position of piston skirt is 5 mm.

Investigation on particulate emissions and combustion characteristics of a common-rail diesel engine fueled with Moringa oleifera biodiesel-diesel blends

In this study, a study of the effects of Moringa Oil Biodiesel (MOB) biodiesel-diesel blends on the engine's performance, exhaust particulate matter, gaseous emissions and combustion characteristics was carried out in a multi-cylinder high-pressure common-rail diesel engine. The experiment involved the use of baseline diesel and several MOB blends (MOB10, MOB20, MOB30 and MOB50) as the fuel for the diesel engine. The results concluded that the engine torques and brake power produced by all of the MOB blends is smaller to the baseline diesel. However, both the MOB blends and baseline diesel produced similar brake thermal efficiency (BTE). It is noticed that the brake specific fuel consumption (BSFC) of all MOB are indicating deterioration, but showing an improvement in the brake specific energy consumption (BSEC). Besides, the peak cylinder pressure and peak HRR indicated a trend of declination with the increasing biodiesel blend ratio. Furthermore, all MOB has shown a great improvement in the emission of carbon monoxide (CO), smoke and particulate matter (PM), except nitrogen oxides (NOx). In short, Moringa oil is suitable to use as a source of biodiesel fuel in the diesel engines without any engine modification needs to be done.

Simulation Study on Influence of Fuel Injection Strategy on Regeneration Performance of Catalytic Particle Filter

The influence rule of fuel injection strategy on regeneration performance of catalytic particle filter (CPF) will be studied in this paper, through using system dynamics, GT-POWER and AVL FIRE to build and match respectively the onedimensional complete machine model of D19 high pressure common rail diesel engine of variable geometry turbocharger (VGT) and the three-dimensional simulation model of CPF, which are based upon the 50% load working condition with 3000r/min. The study shows that with the delay of main injection timing, the regeneration rate of CPF gradually increase, simultaneously, residual volume of particulate matter (PM), pressure drop and NO2 of CPF at exit end decrease. At the earlier main injection timing, with increasing exhaust gas recirculation (EGR) rate, regeneration rate of CPF is decreasing and residual volume of PM is increasing dramatically. At the later main injection timing, with increasing EGR rate, PM residual volume shows trend of rise then descend. Adoption of post injection benefits for regeneration of CPF, with delay of post injection timing, pressure drop and PM residual volume of CPF both show trend of rise then descend, the post injection timing corresponding with the best efficiency of CPF regeneration will be forward lead with increasing of EGR rate. Appropriately enhancing amount of post injection will benefit for regeneration of CPF. And, the negative effect of CPF regeneration will be increased when using post injection and later timing to rise EGR rate.

Effect of Calophyllum Inophyllum biodiesel-diesel blends on combustion, performance, exhaust particulate matter and gaseous emissions in a multi-cylinder diesel engine

In this work, the effects of adding of inedible Calophyllum Inophyllum biodiesel to diesel fuel on performance, gaseous emissions, particulate matter (PM) and combustion characteristics were studied in a medium-duty, high-pressure common-rail turbocharged four-cylinder diesel engine under different speed and torque conditions. The key physicochemical properties of neat biodiesel, biodiesel-diesel blends and diesel were characterized and analysed. The test fuels used were a fossil diesel fuel, B10, B20, B30, and B50 of biodiesel-diesel fuels. The results indicated that all blends of biodiesel fuels have physicochemical properties relatively close to those of petroleum diesel. The experimental results also demonstrated that there are some drawbacks in engine brake power, brake specific fuel consumption (BSFC), and nitrogen oxide (NOx) with the blend of biodiesel in the fuel. Besides, refinement in brake thermal efficiency (BTE) and exhaust emissions were recorded across all engine speeds. Moreover, the emission improvement was characterized by lower carbon monoxide (CO) and reduced in both of the smoke and PM emissions. Also, reduction in the magnitude of peak combustion pressure and heat release rate (HRR) were also found with biodiesel blends. Overall, the results indicated that Calophyllum Inophyllum biodiesel can be used satisfactorily in an unmodified multi-cylinder high-pressure common-rail diesel engine.

Improvement in high load ethanol-diesel dual-fuel combustion by Miller cycle and charge air cooling

At high load, dual-fuel compression ignition engines often rely on exhaust gas recirculation (EGR) to avoid excessive in-cylinder pressure rise rates caused by the autoignition of the premixed fuel. This can adversely affect the net indicated efficiency depending on the resulting fuel/air equivalence ratio and pressure differential across the cylinder used to drive the requested amounts of EGR. In this work, advanced combustion control strategies have been experimentally investigated to improve ethanol-diesel dual-fuel operation at a high engine load of 1.8 MPa net indicated mean effective pressure. Miller cycle and charge air cooling have been explored to reduce the in-cylinder gas temperature and help control the ethanol autoignition process, potentially minimising the EGR requirements and increasing net indicated efficiency. Experiments were carried out on a single-cylinder heavy-duty engine equipped with a high pressure common rail diesel injection, an ethanol port fuel injection, and a variable valve actuation system on the intake camshaft. Exhaust emissions and net indicated efficiency were measured and discussed for different ethanol energy fractions. Early autoignition of the premixed ethanol fuel at the baseline intake valve lift profile resulted in high levels of pressure rise rate, which limited the ethanol energy fraction to 0.26. The application of a Miller cycle strategy via late intake valve closing events effectively delayed the ethanol autoignition process. The reduction of the intake manifold air temperature via an air-to-water charge air cooler also suppressed the early ignition of ethanol. Both approaches allowed for a substantial improvement in terms of the maximum ethanol energy fraction, which was increased to 0.79 without EGR. Moreover, high load dual-fuel operations with Miller cycle and charge air cooling attained higher net indicated efficiency and lower nitrogen oxides emissions than conventional diesel combustion. These improvements can help generate a viable business case of dual-fuel combustion as a technology for future compression ignition engines.

Effects of EGR rate and hydrogen/carbon monoxide ratio on combustion and emission characteristics of biogas/diesel dual fuel combustion engine

This paper investigates the combustion and emission characteristics of dual fuel combustion mode using port injection of biogas combined with direct injection of commercial diesel oil based on a high pressure common rail diesel engine. The effects of EGR rates on combustion and emission characteristics are explored and results from using different port-injected test biogas including Biogas 1# (H2:CO:CH4:N2=5:40:5:50) and Biogas 2# (H2:CO:CH4:N2=15:30:5:50) are also compared. The experimental results show that with the increase of EGR rates, combustion phase retards and ignition delay gets prolonged. NOx emissions decrease monotonically coupled with an effective inhibition once the EGR rate grows over 50%. In the particle size distribution of dual fuel combustion fueled with biogas/diesel, the concentration of nuclear mode particle is high especially for Biogas 1# in high EGR rate. The indicated thermal efficiencies drop gradually as EGR rate increases. It is revealed that under approximately the same EGR level, Biogas 2# with higher hydrogen proportion has higher reactivity when mixed with diesel. With port injection of Biogas 2#, NOx emissions are much higher as well as higher indicated thermal efficiencies are achieved. The high efficiency and low emissions of biogas/diesel dual fuel combustion mode will be achieved under the condition of using EGR, split injection and addition of hydrogen in biogas.

Design and Evaluation for Target Indicated Torque Based Engine Starting Control Strategy in a High Pressure Common Rail Diesel Engine

The diesel engine power demand of the start condition can be separated into two parts including resistance overcoming and acceleration realization for the reason that there is no power output during the starting process. The present paper mainly focuses on the fuel injection quantity control based on the engine power demand especially the acceleration demand for the resistance force is fixed for a specific engine, and the starting acceleration velocity is set as a target curve so that the acceleration process can also be fixed. The feasibility of the start control strategy proposed in this paper was verified by a comparison of the traditional starting control with a constant fuel quantity, and starting performance of the target acceleration based control shows predominance to the constant quantity control. And then the comparison between various starting acceleration processes, which was realized by the settings of acceleration curve slope factor, was conducted and results showed that the acceleration processes with higher slope factors perform better.

Effects of Jatropha biodiesel on the performance, emissions, and combustion of a converted common-rail diesel engine

An experimental investigation into the effects of Jatropha biodiesel fuels on the engine performance, emissions, and combustion characteristics of a single-cylinder high-pressure common-rail diesel engine was performed under six different load operations (0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 MPa). The test fuels included a conventional diesel fuel and three different blends of Jatropha biodiesel fuel (JB10, JB30, and JB50). The results revealed that the biodiesel blended fuels had a significant influence on the brake specific fuel consumption (BSFC) at all of the engine load conditions examined. In general, the use of Jatropha biodiesel blends resulted in a reduction in brake specific nitrogen oxide (BSNOx), brake specific carbon monoxide (BSCO), and smoke emissions, regardless of the load conditions. A large reduction of 20.2% in BSNOx emissions and 69.5% in smoke opacity were found for the engine when it was fuelled with the biodiesel blends. In terms of the engine combustion characteristics, a slightly shorter ignition delay (ID) and faster combustion duration were found to occur with the use of biodiesel blends under all loading operations. It was revealed that the peak apparent heat release rate (AHRR) for biodiesel blends is lower during low load operation; the AHRR was found to be comparable to that of baseline diesel during high-load operation. Finally, the vibration results demonstrated that the largest reduction, 11.3%, in the root mean square (RMS) of acceleration in comparison with the baseline diesel was obtained with JB50 at an engine load of 0.5 MPa.

Research on Fast Driving Control Technology of Electric-Control Injector for Marine High Pressure Common Rail Diesel

Based on the analyses of the current solenoid valve driving circuits in marine diesel, a new type of dual-power double-maintain injector driving circuit is designed for marine high-pressure common-rail diesel. The circuit uses BOOST high voltage (80V) and storage battery low voltage (24V) to make up of dual-power time-sharing driver, which achieves automatic PWM feedback modulation of the solenoid valve injection current from the hardware. Experiments were carried out on a certain type of injector, the results showed that: the driving circuit had fast response time, only 0.045ms from zero to 22A of the solenoid valve current was required; the peak value of driving current has a good consistency, parameters including peakvalue current altitude, lasting time, maintain current altitude and maintain current lasting time could be adjusted flexibly. Besides, the circuit could be flexibly configured without occupying MCU resources.

Effect of Ethanol-Coconut Oil Methyl Ester on the Performance, Emission and Combustion Characteristics of a High-Pressure Common-Rail DI Engine

The effects of using ethanol as additive to biodiesel-diesel blends on engine performance, emissions and combustion characteristics was investigated on a four-cylinder, turbocharged and high-pressure common-rail direct injection diesel engine. Three test fuels have been compared: baseline diesel, coconut oil methyl ester (CME) with 20% of biodiesel by volume (B20) and 5% of ethanol and 20% of CME by volume (B20E5). The tests were performed in steady state conditions at 2000 rpm with 25%, 50% and 75% load setting conditions. The results indicate that higher brake specific fuel consumption and brake thermal efficiency is observed when operating with B20 and B20E5 blend. B20E5 blend shows reduction in smoke opacity, CO and NOx emissions compared to baseline diesel fuel. In terms of combustion characteristics, B20E5 shows slightly higher in both of the peak pressure and peak of HRR at low engine load.

Design and Simulation of Solenoid Valve Driving Circuit Module for High Pressure Common Rail Diesel Injector

According to the principle of BOOST and working characteristics of current mode PWM control chip UC3842, a drive circuit of injector solenoid valve was designed for high pressure common rail diesel engine, and simulation model of drive circuit was build with full use of Multisim. Through the simulation of that model and the practical application of the circuit, the results of comparison show that the design of injector solenoid valve drive circuit is reliable and can meet the working demands of high pressure common rail diesel engine, which provides a theoretical basis and practical application for hardware design of high pressure common rail diesel engine control unit.

Emissions Characteristics of a Diesel Engine with GTL and Biodiesel Fuels

Emission characteristics of an electronic-controlled high pressure common-rail diesel engine with low-blend Gas-to-liquids (GTL) and low-blend biodiesel fuels are studied. Pure diesel fuel, G10 fuel (10% GTL blend with diesel fuel) and B10 fuel (10% biodiesel blend with diesel fuel) are used in this research. The results show that torque of the engine with pure diesel fuel is higher than G10 fuel, and B10 fuel is the lowest. Compared to the pure diesel fuel, the brake specific fuel consumption (BSFC) of the engine with G10 fuel decreases, but the B10 fuel increases slightly. Hydrocarbon (HC) emissions of the engine with G10 fuel or B10 fuel are lower than the pure diesel fuel, and the carbon monoxide (CO) emission increases slightly, and nitrogen oxides (NOx) emissions have no distinct change. Compared to the G10 fuel, the CO and HC emissions of the engine with B10 fuel are lower.

An investigation of the engine performance, emissions and combustion characteristics of coconut biodiesel in a high-pressure common-rail diesel engine

An experimental investigation on engine performance, emissions, combustion and vibration characteristics with coconut biodiesel fuels was conducted in a high-pressure common-rail diesel engine under five different load operations (0.17, 0.34, 0.52, 0.69 and 0.86 MPa). The test fuels included a conventional diesel fuel and four different fuel blends of coconut biodiesel (B10, B20, B30 and B50). The results showed that biodiesel blended fuels have significant influences on the BSFC (brake specific fuel consumption) and BSEC (brake specific energy consumption) at all engine loads. In general, the use of coconut biodiesel blends resulted in a reduction of BSCO (brake specific carbon monoxide) and smoke emissions regardless of the load conditions. A large reduction of 52.4% in smoke opacity was found at engine load of 0.86 MPa engine load with B50. For combustion characteristics, a slightly shorter ignition delay and longer combustion duration were found with the use of biodiesel blends under all loading operations. It was found that generally the biodiesel blends produced lower peak heat release rate than baseline diesel. The vibration results showed that the largest reduction of 13.7% in RMS (root mean square) of acceleration was obtained with B50 at engine load of 0.86 MPa with respect to the baseline diesel.

Study on Combustion and Emission Characteristics of Acidic Oil Biodiesel

In order to develop a new fuel alternative for the diesel engine, experiment of combustion and emission characteristics was carried on a high pressure common rail diesel engine fueled with diesel and acidic oil biodiesel blends, then the results were compared and analyzed. The results indicate that after adding acidic oil biodiesel, the ignition delay is prolonged, combustion pressure, maximum rate of pressure rise and maximum combustion temperature all increase. The maximum combustion heat release rate of blended fuel is higher than diesel at low and middle loads, and lower at high load condition. Compared with diesel, HC emissions of blends decrease dramatically with the increases of blending ratio. NOX emissions of blends are slightly higher than diesel. CO emissions of blends are almost the same as that of diesel. According to the results, acidic oil biodiesel has wide application prospects as an alternative fuel.

Experimental Study on the Influence of Injection Timing on Combustion and Emission of Biodiesel Engine Based on Mechanical Mechanics

This article investigates the effect of different injection timings on the combustion and emission characteristics of a Chinese V high pressure common rail diesel engine fuelled with blends of biodiesel and diesel (the volume ration of biodiesel is 20%). The Results show that, retarded injection timing resulted in decrease of ignition delay and combustion duration at all loads, except for 25 percent of full load. Peak cylinder pressure and maximum rate of peak pressure significantly reduced at retarded injection timing. The cycle-by-cycle variation of peak cylinder pressure first increased and then decreased, and the highest was obtained at -4°CA of injection timing. BSFC increased by 0.3% to 4.2% with retarded injection timing. Postponing injection timing effectively reduced NOx emission. NOx and PM emissions simultaneously decreased at full load when postponing injection. At 25% load HC and CO emissions were significantly higher than other loads and the effect of injection timing was most obvious.

The Study about Combustion and Emission Characteristics of n-Butanol/Diesel Fuel Mixture

Experiment of fuel combustion and emission characteristics was carried on a turbocharged intercooled electronically controlled high pressure common rail diesel engine with n-butanol/diesel blends, then the results of experiment were compared and analyzed. The results show that with the adding of n-butanol, the maximum combustion pressure gradually increases and the maximum heat release rate gradually reduces; compared with diesel, CO emissions of the blends are slightly lower and decrease with the increasing load; HC emissions of the mixture fuel are higher and decrease first then increase with the increasing load; at 2000rpm, NOX emissions of the blends are a little lower than the pure diesel in small loads but higher in other loads, and increase with the adding of the load.

Impacts of Continuously Regenerating Trap Technology on the Regulated Gas Emissions for a China-V Diesel Engine

In this paper, the effects of continuously regenerating trap (CRT) after-treatment system on performance, fuel efficiency and regulated gas emissions from a turbocharged electronically controlled high pressure common rail diesel engine that meets China-V regulation have been investigated. The test results revealed that: the power and torque of diesel engine after the installation of CRT after-treatment system declines slightly, which is limited to 2%, and the rise in brake specific fuel consumption is around 2%. At the same time, the emission of CO decreased significantly by 86% to 94%, NOx also reduced slightly by 8% to 12%. However, the emission of HC dropped at part loads and rose at full load modes since the original engine emission is already quite low.