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1
Fang, T.-G., R. E. Coverdill, C.-F. F. Lee, and R. A. White. "Effect of the injection angle on liquid spray development in a high-speed direct-injection optical diesel engine." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 223, no. 8 (August 1, 2009): 1077–92. http://dx.doi.org/10.1243/09544070jauto1221.
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In this paper, the spray development and its interaction with the piston geometry were investigated in a small-bore high-speed direct-injection optical diesel engine. The effects of injection angle, injection timing, injection pressure, and injection fuel quantity were studied. The entire liquid spray cycle was visualized by a background-corrected Mie-scattering technique using a high-speed digital video camera synchronized with a high-repetition-rate copper vapour laser. For some conditions, the initial injection velocity was estimated quantitatively. The results show that the injection angle and injection timing predominantly control the spray interaction with the piston geometry and the resulting air—fuel mixing mode. Narrow-angle injection leads to a significantly different air—fuel mixing process from the traditional wide-angle injector. If properly controlled, the narrow-angle direct-injection technique offers more flexibility on injection timing control with the fuel confined in the central bowl region without wetting the cylinder liner.
2
Lu, Yingying, and Wanhua Su. "Effects of the injection parameters on the premixed charge compression ignition combustion and the emissions in a heavy-duty diesel engine." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 231, no. 7 (April 23, 2017): 915–26. http://dx.doi.org/10.1177/0954407017701023.
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Numerous combustion strategies have been suggested for compression ignition engines in order to meet the stringent emission regulations with minimal sacrifice in the fuel economy. Premixed charge compression ignition combustion has the potential to reduce the nitrogen oxide emissions and the soot emissions while maintaining a high thermal efficiency and has become the research focus recently. Experiments and simulations were used to study the effects of the injection mode and the injection timing on the premixed charge compression ignition combustion and the emissions in a heavy-duty diesel engine at low and medium loads. The results reveal the following. At low loads, when the injection timing of a single injection is 35° crank angle before top dead centre because of the impinging position of the spray, the mixture is divided into two parts: the fuel above the chamber and the fuel in the piston bowl. This helps to utilize fully the in-cylinder air to form a homogeneous mixture. Also the nitrogen oxide emissions are the lowest. At medium loads, with a single injection, the injection mass is increased, the injection duration is prolonged and the mixing timing is reduced. As a result, the soot emissions, the carbon monoxide emissions and the unburned hydrocarbon emissions are increased dramatically; the best emissions are gained at an injection timing of 35° crank angle before top dead centre owing to the combined effect of the optimized mixing time and the optimized mixing space. At medium loads, with multiple injections, the injection mass is divided into four pulses, the mixing timings of which are all increased. The mixing space of the fuel–air mixture is also improved, and a more homogeneous mixture is obtained, which is beneficial to decreasing the soot emissions, the carbon monoxide emissions and the unburned hydrocarbon emissions in comparison with those for the single-injection case. When the injection timings of multiple injections are 80° crank angle before top dead centre, 65° crank angle before top dead centre, 50° crank angle before top dead centre and 35° crank angle before top dead centre, the best trade-off between the performance and the emissions can be achieved at medium loads.
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Khalid, Amir, Azwan Sapit, M. N. Anuar, Him Ramsy, Bukhari Manshoor, Izzuddin Zaman, and Zamani Ngali. "Analysis of Fuel Injection Parameter on Biodiesel and Diesel Spray Characteristics Using Common Rail System." Advanced Materials Research 974 (June 2014): 362–66. http://dx.doi.org/10.4028/www.scientific.net/amr.974.362.
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Precise control of fuel injection is essential in modern diesel engines especially in controlling the precise injection quantity, flexible injection timing, flexible rate of injection with multiple injections and high injection pressures. It was known that the fuel-air mixing is mainly influenced by the fuel injection system and injector nozzle characteristics. Thus, mixture formation during ignition process associated with the exhaust emissions. The purpose of this study is to investigate the influence of spray characteristics on the mixture formation. In this study, common rail injector systems with different model of injector were used to simulate the actual mixture formation inside the engine chamber. The optical visualization system was constructed with a digital video camera in order to investigate the detailed behavior of mixture formation. This method can capture spray penetration length, spray angle, spray evaporation and mixture formation process clearly. The spray characteristic such as the penetration length, spray angle and spray area are increasing when the injection pressure increased. The mixture formation can be improved effectively by increasing the injection pressure.
4
Luo, Li, Bin Xu, Zhi Hao Ma, Jian Wu, and Ming Li. "Effect of Injection Timing on Combustion Characteristics of a DI Diesel Engine Fuelled with Pistacia chinensis Bunge Seed Biodiesel." Advanced Materials Research 614-615 (December 2012): 337–42. http://dx.doi.org/10.4028/www.scientific.net/amr.614-615.337.
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In this study, the effect of injection timing on combustion characteristics of a direct injection, electronically controlled, high pressure, common rail, turbocharged and intercooled engine fuelled with different pistacia chinensis bunge seed biodiesel/diesel blends has been experimentally investigated. The results indicated that brake specific fuel consumption reduces with the increasing of fuel injection advance angle and enhances with the increasing of biodiesel content in the blends. The peak of cylinder pressure and maximum combustion temperature increase evidently with the increment of fuel injection advance angle. However, the combustion of biodiesel blends starts earlier than diesel at the same fuel injection advance angle. At both conditions, the combustion duration and the peak of heat release rate are insensitive to the changing of injection timing.
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Chang, Hsu Fang, Wang Chih Cheng, and Feng Tsai Weng. "Effect of End of Injection Angle on Performance and Emission Formation for a Gasoline Engine." Applied Mechanics and Materials 300-301 (February 2013): 27–31. http://dx.doi.org/10.4028/www.scientific.net/amm.300-301.27.
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The method of supplying fuel for an electronic-controlled fuel injection system is calculating the required fuel amounts under various operating conditions of engine and controlling the opening and closing timing of fuel injection. After fuel injection, the effects of condensation and atomization of injected fuel as well as fuel mixing for combustion are strongly dominated by the opening timing and duration of intake valves. This can further affect the emission composition and performance for an engine. As the emission regulation is getting more stringent and the requirement for minimizing specific fuel consumption is becoming more urgent, investigating the effect of closing timing of fuel injection has turned out to be a major issue. Therefore, this paper presents a study about a series of engine tests to investigate the effect of end of injection angle on the performance and emission formation for a gasoline engine. In these tests, the values of end of injection angle are adjusted using a control software for electronic-controlled fuel injection system so that the results can be analyzed under various engine speeds and loads.
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WOJS, Marcin, Piotr ORLIŃSKI, and Jakub LASOCKI. "The effect of alternative fuels injection timing on toxic substances formation in CI engines." Combustion Engines 168, no. 1 (February 1, 2017): 73–76. http://dx.doi.org/10.19206/ce-2017-112.
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The present study describes selected issues associated with the emission level in toxic exhaust gases and fuel injection timing. The study was focused on the following types of fuels: Diesel oil (the base fuel) and the other fuels were the mixture of fatty acid methyl ester with Camelina (L10 – diesel fuel with 10% V/V FAME of Camelina and L20 – diesel fuel with 10% V/V FAME of Camelina) was used. Fuel injection advanced angle was set for three different values – the factory setting – 12° before TDC, later injection – 7° and earlier injection – 17°. The most important conclusion is that in most measurement points registered in the same engine operating conditions, the concentration of fuel NOx in L10 and L20 increased but PM emissions decreased which is caused by active oxygen located in the internal structure of the fuel. This fact contributes to the rise in temperature during the combustion process. At the same time factory settings of the angle makes NOx emissions lower and close to reference fuel.
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Perang, Mohd Rozi Mohd, Abdul Latiff Zulkarnain, Azhar Abdul Aziz, and Mohamad Azzad Mokhri. "Design of a Four-Stroke Homogeneous Charge Compression Ignition Engine." Applied Mechanics and Materials 388 (August 2013): 229–34. http://dx.doi.org/10.4028/www.scientific.net/amm.388.229.
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This research is to study the operation of the four-stroke HCCI engine. The design and analysis works have been performed using computer software which is GT-Power and Solidwork to study on the engine performance simulation work and 3-D modelling on the combustion chamber designed respectively. The design is based on 4-cylinder passenger car, 2000 cc and a four-stroke cycle engine. The compression ratio used is 10. The fuel used is ethanol in which the air-fuel ratio (AFR) is 9. The parameters selected have typical range of value based on the previous study and research done. With the use of GT-power, the analysis will consider two parameters which are the cam timing angle and the injection timing angle to get the optimum result for the HCCI engine. The typical angle of cam timing angle is between 2600 – 2700 since this is the moment of the compression cycle of the engine. For the injection timing angles, the angles that will be studied for this project are 50, 00, -50, -100,-150 and -200 relative to Top Dead Centre (TDC). The objective is to obtain the maximum torque and brake power when the engine speed is in between 4000 rpm to 5000 rpm and 6000 rpm to 7000 rpm respectively. Finally, the optimum conditions for the engine to perform better are at 2640 of cam timing angle for the valve and at -50 before TDC for the injection timing angle. The maximum torque and brake power achieved is 37.60 Nm at 4000 rpm and 23.46 kW at 7000 rpm.
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Xu, Bin, Li Luo, Jian Wu, and Zhi Hao Ma. "The Influence of Injection Timing on Emissions Characteristics of a DI Diesel Engine Fuelled with Pistacia Chinensis Bunge Seed Biodiesel." Advanced Materials Research 634-638 (January 2013): 846–51. http://dx.doi.org/10.4028/www.scientific.net/amr.634-638.846.
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The effect of various fuel injection advance angles on the emissions of an electronically controlled, high pressure, common rail, turbocharged GW4D20 diesel engine fuelled with different pistacia chinensis bunge seed biodiesel/diesel blends has been experimentally investigated. The results indicate that brake specific fuel consumption reduces with the increasing of fuel injection advance angle, and the BSFC of blends is higher than diesel. At 25% load, CO and THC are significantly reduced compared with higher load. The CO emission increases with the increment of fuel injection advance angle. At 75% load, the CO of B10 is lowest, B20 highest. At the same speed, NOx increases with increment of fuel injection advance angle for diesel and biodiesel blends dramatically. However, NOx of blends and diesel are deteriorated at high load, but there are no obvious differences among them.
9
Tennison, P. J., and R. Reitz. "An Experimental Investigation of the Effects of Common-Rail Injection System Parameters on Emissions and Performance in a High-Speed Direct-Injection Diesel Engine." Journal of Engineering for Gas Turbines and Power 123, no. 1 (June 6, 1999): 167–74. http://dx.doi.org/10.1115/1.1340638.
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An investigation of the effect of injection parameters on emissions and performance in an automotive diesel engine was conducted. A high-pressure common-rail injection system was used with a dual-guided valve covered orifice nozzle tip. The engine was a four-valve single cylinder high-speed direct-injection diesel engine with a displacement of approximately 12 liter and simulated turbocharging. The engine experiments were conducted at full load and 1004 and 1757 rev/min, and the effects of injection pressure, multiple injections (single vs pilot with main), and pilot injection timing on emissions and performance were studied. Increasing the injection pressure from 600 to 800 bar reduced the smoke emissions by over 50 percent at retarded injection timings with no penalty in oxides of nitrogen NOx or brake specific fuel consumption (BSFC). Pilot injection cases exhibited slightly higher smoke levels than single injection cases but had similar NOx levels, while the single injection cases exhibited slightly better BSFC. The start-of-injection (SOI) of the pilot was varied while holding the main SOI constant and the effect on emissions was found to be small compared to changes resulting from varying the main injection timing. Interestingly, the point of autoignition of the pilot was found to occur at a nearly constant crank angle regardless of pilot injection timing (for early injection timings) indicating that the ignition delay of the pilot is a chemical delay and not a physical (mixing) one. As the pilot timing was advanced the mixture became overmixed, and an increase of over 50 percent in the unburned hydrocarbon emissions was observed at the most advanced pilot injection timing.
10
Sudarmanta, Bambang, Alham A. K. Mahanggi, Dori Yuvenda, and Hary Soebagyo. "Optimization of Injection Pressure and Injection Timing on Fuel Sprays, Engine Performances and Emissions on a Developed DI 20C Biodiesel Engine Prototype." International Journal of Heat and Technology 38, no. 4 (December 31, 2020): 827–38. http://dx.doi.org/10.18280/ijht.380408.
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Biodiesel, as a renewable fuel that has the potential to replace diesel fossil fuels. With properties in the form of viscosity, density, and surface tension, which are higher than diesel fossil fuel, biodiesel produces poor spray characteristics, and also the high cetane number and oxygen content so that the ignition delay is shorter causes the start of combustion will shift more forward, therefore need to improve injection parameters including injection pressure and timing. The aim of this research is to get the optimal injection parameter optimization so as to improve engine performances and emissions. The method used is to increase the fuel injection pressure from 200 to 230 kg/cm2 and the injection timings were retarded from 22° to 16° BTDC. The results show that increasing injection pressure can improve spray characteristics as indicated by shorter penetration and smaller spray diameter of 30% and 9.8%, respectively and increase in spray spread angle of 21.9%. Then the optimization of engine performances and emissions, obtained at an injection pressure of 230 kg/cm2 and injection timing of 16° BTDC with an increase of power and thermal efficiency of 3.9% and 13.9%, respectively and reduction in smoke emissions of 45.2% at high load.
11
Zhao, Le, Yu Zhang, Yuanjiang Pei, Anqi Zhang, and Muhsin M. Ameen. "CFD-Guided Evaluation of Spark-Assisted Gasoline Compression Ignition for Cold Idle Operation." Sustainability 13, no. 23 (November 26, 2021): 13096. http://dx.doi.org/10.3390/su132313096.
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A closed-cycle, three-dimensional (3D) computational fluid dynamics (CFD) analysis campaign was conducted to evaluate the performance of using spark plugs to assist gasoline compression ignition (GCI) combustion during cold idle operations. A conventional spark plug using single-sided J-strap design was put at a location on the cylinder head to facilitate spray-guided spark assistance. Ignition was modeled with an L-type energy distribution to depict the breakdown and the arc-to-glow phases during the energy discharge process. Several key design parameters were investigated, including injector clocking, number of nozzle holes, spray inclusion angle, number of fuel injections, fuel split ratio, and fuel injection timings. The study emphasized the region around the spark gap, focusing on flame kernel formation and development and local equivalence ratio distribution. Flame kernel development and the ignition process were found to correlate strongly with the fuel stratification and the flow velocity near the spark gap. The analysis results showed that the flame kernel development followed the direction of the local flow field. In addition, the local fuel stratification notably influenced early-stage flame kernel development due to varying injection spray patterns and the fuel injection strategies. Among these design parameters, the number of nozzle holes and fuel injection timing had the most significant effects on the engine combustion performance.
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Sun, Ying Jie, Yang Li, Chun Yu Wang, Yao Chun Li, and Yun Feng Liang. "Research of Working Mode Conversion Based on GDI Engine." Applied Mechanics and Materials 741 (March 2015): 546–49. http://dx.doi.org/10.4028/www.scientific.net/amm.741.546.
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This paper designs the control strategy of working mode conversion from stoichiometric homogeneous mixture to lean homogeneous mixture. First of all, after the types and parameters of electric hardware were selected in this system, a complete circuit layout of engine control system was designed, which used microcontroller named MC9S12XDP512 as control chip and the test bench was built. Then, we adjust the fuel injection pulse width and throttle opening to realize lean burn (lambda = 1.4) of torque being 40N.m at speed of 2500 r / min, and adjust injection timing to find the best injection timing which is 350 crank angle degree, and adjust the ignition advance angle to find the best ignition advance angle which is 13 crank angle degree. Finally, the work mode conversion was completed by the optimal parameters linear interpolation, reducing the fuel injection pulse width and increasing the throttle opening at the same time.
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Ding, Carl-Philipp, David Vuilleumier, Namho Kim, David L. Reuss, Magnus Sjöberg, and Benjamin Böhm. "Effect of engine conditions and injection timing on piston-top fuel films for stratified direct-injection spark-ignition operation using E30." International Journal of Engine Research 21, no. 2 (September 5, 2019): 302–18. http://dx.doi.org/10.1177/1468087419869785.
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Mid-level ethanol/gasoline blends can provide knock resistance benefits for stoichiometric spark-ignition engine operation, but previous studies have identified challenges associated with spray impingement and wall wetting, leading to excessive particulate matter emissions. At the same time, stratified-charge spark-ignition operation can provide increased thermal efficiency, but care has to be exercised to avoid excessive in-cylinder soot formation. In support of the use of mid-level ethanol/gasoline blends in advanced spark-ignition engines, this study presents spray and fuel-film measurements in a direct-injection spark-ignition engine operated with a 30 vol.%/70 vol.% ethanol/gasoline blend (E30). Crank-angle resolved fuel-film measurements at the piston surface are conducted using two different implementations of the refractive index matching technique. A small-angle refractive index matching implementation allows quantification of the wetted area, while a large-angle refractive index matching implementation enables semi-quantitative measurements of fuel-film thickness and volume, in addition to fuel-film area. The fuel-film measurements show that both the amount of fuel deposited on the piston and the shape of the fuel-film patterns are strongly influenced by the injection timing, duration, intake pressure, and coolant temperature. For combinations of high in-cylinder gas density and long injection duration, merging of the individual spray plumes, commonly referred to as spray collapse, can cause a dramatic change to the shape and thickness of the wall fuel films. Overall, the study provides guidance to engine designers aiming at minimizing wall wetting through tailored combinations of injection timings and durations.
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CZAJKA, Jakub, Ireneusz PIELECHA, and Krzysztof WISŁOCKI. "A comparative analysis of diesel fuel injection parameters in piezoelectric and electromagnetic fuel injectors." Combustion Engines 138, no. 3 (July 1, 2009): 54–63. http://dx.doi.org/10.19206/ce-117177.
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The paper presents the results of a comparative analysis of the changes in the injection spray shape and penetration and its vertex angle during the injection through piezoelectric and electromagnetic fuel injectors. The results of the observation of the fuel spray with the use of high speed camera (100 ms frame frequency) have been presented. Moreover, the parameterization and digital processing (including its automation) of the obtained image have too been presented. The influence of the pressure and the timing of the injection on the variable-in-time spray parameters have been shown. A mathematical model describing these relations has been proposed.
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Fang, T.-G., R. E. Coverdill, C.-F. F. Lee, and R. A. White. "Low-sooting combustion in a small-bore high-speed direct-injection diesel engine using narrow-angle injectors." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 222, no. 10 (October 1, 2008): 1927–37. http://dx.doi.org/10.1243/09544070jauto751.
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An optically accessible high-speed direct-injection diesel engine was used to study the effects of injection angles on low-sooting combustion. A digital high-speed camera was employed to capture the entire cycle combustion and spray evolution processes under seven operating conditions including post-top-dead centre (TDC) injection and pre-TDC injection strategies. The nitrogen oxide (NO x) emissions were also measured in the exhaust pipe. In-cylinder pressure data and heat release rate calculations were conducted. All the cases show premixed combustion features. For post-TDC injection cases, a large amount of fuel deposition is seen for a narrower-injection-angle tip, i.e. the 70° tip, and ignition is observed near the injector tip in the centre of the bowl, while for a wider-injection-angle tip, namely a 110° tip, ignition occurs near the spray tip in the vicinity of the bowl wall. The combustion flame is near the bowl wall and at the central region of the bowl for the 70° tip. However, the flame is more distributed and centralized for the 110° tip. Longer spray penetration is found for the pre-TDC injection timing cases. Liquid fuel impinges on the bowl wall or on the piston top and a fuel film is formed. Ignition for all the pre-TDC injection cases occur in a distributed way in the piston bowl. Two different combustion modes are observed for the pre-TDC injection cases including a homogeneous bulky combustion flame at earlier crank angles and a heterogeneous film combustion mode with luminous sooting flame at later crank angles. In terms of soot emissions, NO x emissions, and fuel efficiency, results show that the late post-TDC injection strategy gives the best performance.
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Kodavasal, Janardhan, Christopher P. Kolodziej, Stephen A. Ciatti, and Sibendu Som. "Effects of injection parameters, boost, and swirl ratio on gasoline compression ignition operation at idle and low-load conditions." International Journal of Engine Research 18, no. 8 (November 3, 2016): 824–36. http://dx.doi.org/10.1177/1468087416675709.
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In this work, we study the effects of injector nozzle inclusion angle, injection pressure, boost, and swirl ratio on gasoline compression ignition combustion. Closed-cycle computational fluid dynamics simulations using a 1/7th sector mesh representing a single cylinder of a four-cylinder 1.9 L diesel engine, operated in gasoline compression ignition mode with 87 anti-knock index (AKI) gasoline, were performed. Two different operating conditions were studied—the first is representative of idle operation (4 mg fuel/cylinder/cycle, 850 r/min), and the second is representative of a low-load condition (10 mg fuel/cylinder/cycle, 1500 r/min). The mixture preparation and reaction space from the simulations were analyzed to gain insights into the effects of injection pressure, nozzle inclusion angle, boost, and swirl ratio on achieving stable low-load to idle gasoline compression ignition operation. It was found that narrower nozzle inclusion angles allow for more reactivity or propensity to ignition (determined qualitatively by computing constant volume ignition delays) and are suitable over a wider range of injection timings. Under idle conditions, it was found that lower injection pressures helped to reduce overmixing of the fuel, resulting in greater reactivity and ignitability (ease with which ignition can be achieved) of the gasoline. However, under the low-load condition, lower injection pressures did not increase ignitability, and it is hypothesized that this is because of reduced chemical residence time resulting from longer injection durations. Reduced swirl was found to maintain higher in-cylinder temperatures through compression, resulting in better ignitability. It was found that boosting the charge also helped to increase reactivity and advanced ignition timing.
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Yang, Renyou, Gerasimos Theotokatos, and Dracos Vassalos. "Parametric investigation of a large two-stroke marine high-pressure direct injection engine by using computational fluid dynamics method." Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 234, no. 3 (January 21, 2020): 699–711. http://dx.doi.org/10.1177/1475090219895639.
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This study aims at the parametric investigation of the gas injection system settings of a large marine two-stroke dual fuel engine by using a developed and customized CFD method in the ANSYS Fluent software. The investigated engine injection system parameters include the gas injection timing, the gas injection duration, the gas injector lateral angle, and the gas injector holes number. Based on the comparison of the predicted performance parameters for the closed-cycle processes, the results indicate that the gas injector lateral angle is the most significant parameter that affects the engine power as well as the NO and CO2 emissions. For satisfying the contradictory objectives of retaining the engine power and reducing the NO and CO2 emissions, appropriate design settings for the gas injection are recommended for the investigated engine operation in the gas mode at 75% load.
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Canakci, M., and R. D. Reitz. "Effect of Optimization Criteria on Direct-Injection Homegeneous Charge Compression Ignition Gasoline Engine Performance and Emissions Using Fully Automated Experiments and Microgenetic Algorithms." Journal of Engineering for Gas Turbines and Power 126, no. 1 (January 1, 2004): 167–77. http://dx.doi.org/10.1115/1.1635395.
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Homogeneous charge compression ignition (HCCI) is a new low-emission engine concept. Combustion under homogeneous, low equivalence ratio conditions results in modest temperature combustion products, containing very low concentrations of NOx and PM as well as providing high thermal efficiency. However, this combustion mode can produce higher HC and CO emissions than those of conventional engines. Control of the start of combustion timing is difficult with pre-mixed charge HCCI. Accordingly, in the present study charge preparation and combustion phasing control is achieved with direct injection. An electronically controlled Caterpillar single-cylinder oil test engine (SCOTE), originally designed for heavy-duty diesel applications, was converted to a direct-injection gasoline engine. The engine features an electronically controlled low-pressure direct injection-gasoline (DI-G) injector with a 60 deg spray angle that is capable of multiple injections. The use of double injection was explored for emission control, and the engine was optimized using fully automated experiments and a microgenetic algorithm optimization code. The variables changed during the optimization include the intake air temperature, start of injection timing, and the split injection parameters (percent mass of fuel in each injection, dwell between the pulses) using three different objective (merit) functions. The engine performance and emissions were determined at 700 rev/min with a constant fuel flow rate at 10 MPa fuel injection pressure. The results show the choice of merit or objective function (optimization goal) determines the engine performance, and that significant emission reductions can be achieved with optimal injection strategies. Merit function formulations are presented that minimized PM, HC, and NOx emissions, respectively.
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Saravanan, N., and G. Nagarajan. "An experimental investigation on performance, emissions, and combustion in a manifold injection for different exhaust gas recirculation flowrates in hydrogen—diesel dual-fuel operations." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 222, no. 11 (November 1, 2008): 2131–45. http://dx.doi.org/10.1243/09544070jauto921.
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Hydrogen is receiving considerable attention as an alternative fuel to replace the rapidly depleting petroleum-based fuels. Its clean burning characteristics help to meet the stringent emission norms. In this experimental investigation a single-cylinder diesel engine was converted to operate in hydrogen—diesel dual-fuel mode. Hydrogen was injected in the intake manifold and the diesel was injected directly inside the cylinder. The injection timing and the injection duration of hydrogen were optimized on the basis of performance and emissions. Best results were obtained with hydrogen injection at gas exchange top dead centre with an injection duration of 30° crank angle. The flowrate of hydrogen was optimized as 7.5l/min with optimized injection timing and duration. The optimized exhaust gas recirculation (EGR) flowrate was 20 per cent at 75 per cent load. The optimized timings were chosen on the basis of performance, emission, and combustion characteristics. The EGR technique was adopted in the hydrogen—diesel dual-fuel mode by varying the EGR flowrate from 0 per cent to 25 per cent in steps of 5 per cent. The maximum quantity of exhaust gases recycled during the test was 25 per cent (up to 75 per cent load); beyond that unstable combustion was observed with an increase in smoke. The brake thermal efficiency with 20 per cent EGR decreases by 9 per cent compared with diesel. The nitrogen oxide (NO x) emission in hydrogen manifold injection decreases by threefold with 20 per cent EGR operation at full load. The NO x emission tends to reduce drastically with increase in the EGR percentage at all load conditions owing to the increase in heat capacity of the exhaust gases. The smoke decreases by 80 per cent in the dual-fuel operation compared with diesel at 75 per cent load.
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Canakci, M., and R. D. Reitz. "Experimental optimization of a direct injection homogeneous charge compression ignition gasoline engine using split injections with fully automated microgenetic algorithms." International Journal of Engine Research 4, no. 1 (February 1, 2003): 47–60. http://dx.doi.org/10.1243/146808703762826642.
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Homogeneous charge compression ignition (HCCI) is receiving attention as a new low-emission engine concept. Little is known about the optimal operating conditions for this engine operation mode. Combustion under homogeneous, low equivalence ratio conditions results in modest temperature combustion products, containing very low concentrations of NOx and particulate matter (PM) as well as providing high thermal efficiency. However, this combustion mode can produce higher HC and CO emissions than those of conventional engines. An electronically controlled Caterpillar single-cylinder oil test engine (SCOTE), originally designed for heavy-duty diesel applications, was converted to an HCCI direct injection (DI) gasoline engine. The engine features an electronically controlled low-pressure direct injection gasoline (DI-G) injector with a 60° spray angle that is capable of multiple injections. The use of double injection was explored for emission control and the engine was optimized using fully automated experiments and a microgenetic algorithm optimization code. The variables changed during the optimization include the intake air temperature, start of injection timing and the split injection parameters (per cent mass of fuel in each injection, dwell between the pulses). The engine performance and emissions were determined at 700 r/min with a constant fuel flowrate at 10 MPa fuel injection pressure. The results show that significant emissions reductions are possible with the use of optimal injection strategies.
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Solsjö, Rickard, Mehdi Jangi, Bengt Johansson, and Xue-Song Bai. "The Role of Multiple Injections on Combustion in a Light-Duty PPC Engine." Energies 13, no. 21 (October 22, 2020): 5535. http://dx.doi.org/10.3390/en13215535.
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This paper presents a numerical investigation of the ignition and combustion process of a primary reference fuel in a partially premixed light-duty internal combustion (PPC) engine. Partially pre-mixed combustion is achieved by employing a multiple injection strategy with three short injection events of fuel pulses. The timing of the first two fuel pulses, 48 and 22 crank angle degrees before top dead center, are chosen with the purpose to stratify the fuel and air charge, whereas the third injection, at five crank angle degrees before top dead center, serves as an actuator of the main heat release. In addition to this baseline injection, three alternative injection strategies are studied, including a split-fuel two-injection strategy and modified triple-injection strategies. Large eddy simulations are employed utilizing a skeletal chemical kinetic mechanism for primary reference fuel capable of capturing the low-temperature ignition and the high temperature combustion. The large eddy simulation (LES) results are compared with experiments in an optical accessible engine. The results indicate that the first ignition sites are in the bowl region where the temperature is relatively higher, and the reaction fronts thereafter propagate in the swirl direction and towards the centerline of the cylinder. The charge from the first two injections initially undergoes low-temperature reactions and thereafter high-temperature reservoirs are formed in the bowl region. The main heat-release is initiated in the engine when the fuel from the third injection reaches the high-temperature reservoirs. Finally, the remaining fuel in the lean mixtures from the first two injections is oxidized. By variation of the injection strategy, two trends are identified: (1) by removing the second injection a higher intake temperature is required to enable the ignition of the charge, and (2) by retarding second injection, a longer ignition delay is identified. Both can be explained by the stratification of fuel and air mixture, and the resulting reactivity in various equivalence ratio and temperature ranges. The LES results reveal the details of the charge stratification and the subsequent heat release process. The present results indicate a rather high sensitivity of partially premixed combustion process to the injection strategies.
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Benajes, J., R. Payri, S. Molina, and V. Soare. "Investigation of the Influence of Injection Rate Shaping on the Spray Characteristics in a Diesel Common Rail System Equipped with a Piston Amplifier." Journal of Fluids Engineering 127, no. 6 (July 27, 2005): 1102–10. http://dx.doi.org/10.1115/1.2062767.
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The quality of the mixing process of fuel and air in a direct injection diesel engine relies heavily on the way the spray develops when injected into the combustion chamber. Among other factors, the spray development depends on the injection rate of the fuel delivered by the injector. The paper presents a study, at both a macroscopic and microscopic level, of a Diesel spray generated by a common-rail injection system featuring a piston pressure amplifier. By modifying the timing and the duration of the injector and amplifier piston actuation, it is possible to obtain high injection pressures up to 180MPa, and different shapes for the injection rate, which would not be achievable with a regular common rail injection system. The spray evolution produced by three different injection rate shapes (square, ramp, and boot) has been investigated in an injection test rig, by means of visualization and PDPA techniques, at different injection conditions. The main conclusions are the important effect on spray penetration of the initial injection rate evolution and the small influence of the maximum injection pressure attained at the end of the injection event. Smaller or even negligible effects have been found on the spray cone angle and on the droplet Sauter mean diameter.
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Dai, Zih-Chun. "Performance verification of heavy-duty motorcycles adjusting intake and exhaust timing." Journal of Physics: Conference Series 2141, no. 1 (December 1, 2021): 012007. http://dx.doi.org/10.1088/1742-6596/2141/1/012007.
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Abstract Heavy-duty locomotives with large exhaust vehicles have become a common means of transportation for Taiwanese. However, for car owners to increase power output, improve efficiency, and reduce fuel use, the original factory has designed demand settings for cost, environmental protection, and regulations. This leads to the sacrifice of the performance of the original car design, so the RC2 Super ECU is used to replace the original injection computer, and the air-fuel ratio, ignition angle and exhaust pipe are modified. Without the need to change the structure of the heavy locomotive, the horsepower of the heavy locomotive is improved. It is pointed out that the modification of these three original factory settings has greatly improved the overall speed performance of the heavy-duty locomotive horsepower. Therefore, it is proposed that “heavy locomotive performance verification by changing the timing of intake and exhaust” is mainly to verify the performance benefits and performance brought about by modifying the air-fuel ratio, ignition angle and exhaust pipe.
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Zhang, Peng, Jimin Ni, Xiuyong Shi, Sheng Yin, and Dezheng Zhang. "Effects of Ignition Timing on Combustion Characteristics of a Gasoline Direct Injection Engine with Added Compressed Natural Gas under Partial Load Conditions." Processes 9, no. 5 (April 26, 2021): 755. http://dx.doi.org/10.3390/pr9050755.
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The gasoline/natural gas dual-fuel combustion mode has been found to have unique advantages in combustion. The ignition timing has a significant impact on the combustion characteristics of gasoline engines. Thus, here we study the combustion characteristics of gasoline/natural gas dual-fuel combustion mode to determine the details of their respective advantages under cooperative combustion. A direct-injection turbocharged gasoline engine was modified, and an engine experimental platform was built for the coordinated control of gasoline direct-injection and natural gas port injection. A low-speed and low-load operating point was selected, and the in-cylinder pressure, heat release rate, pressure rise rate, combustion temperature, ignition delay, and combustion duration under the coordinated combustion of gasoline and natural gas dual fuel at the ignition moment were studied through bench tests among other typical combustion parameters. The results show that with the increase of the ignition advance angle, the maximum cylinder pressure, heat release rate, pressure rise rate, and maximum combustion temperature increase. The ignition advance angle is 28°CA-BTDC, and PES40 has the best fuel synergy effect and the best power performance improvement. The effect of the advance of the ignition advance angle on the ignition delay and the combustion duration reaches the peak at 20°CA-BTDC–22°CA-BTDC, and the improvement of the two periods is more significant at PES60.
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Hill, P. G., and B. Douville. "Analysis of Combustion in Diesel Engines Fueled by Directly Injected Natural Gas." Journal of Engineering for Gas Turbines and Power 122, no. 1 (July 27, 1999): 141–49. http://dx.doi.org/10.1115/1.483185.
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A single-cylinder two-stroke (DDC 1-71) diesel engine has been fueled with natural gas directly injected at high pressure into the engine cylinder. Prior to injection of the natural gas, a quantity of diesel fuel is injected into the cylinder (from the same injector) to provide for gas ignition. Tests have been conducted at medium load and speed over a wide range of injection timing, and with both conventional diesel and gas/diesel operation. With natural gas fueling, significant reduction in nitrogen oxide emissions have been measured without significant loss in efficiency, relative to conventional diesel operation. Using measurements of cylinder pressure development, a new method of combustion analysis has been used to estimate mass burning rate, burned gas temperature, and rate of nitrogen oxide (NO) generation. The method uses a nonlinear regression technique to determine the distribution with crank angle of the cylinder heat loss rate. The method assumes that NO formation takes place within one turbulent mixing time following combustion of each fuel-air increment. Comparison of measured and calculated NO concentration in the exhaust over the whole range of injection timing shows that for both conventional diesel and gas/diesel operation the effective turbulent mixing period is equivalent to 4 degrees of crank angle at 1250 RPM. The results demonstrate that a mass burned method can be used to infer cylinder temperature distributions and NO formation rate as well as the progress of combustion. [S0742-4795(00)02101-3]
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Fansler, T. D., M. C. Drake, B. Stojkovic, and M. E. Rosalik. "Local fuel concentration, ignition and combustion in a stratified charge spark combustion in a stratified charge spark ignited direct injection engine: Spectroscopic, imaging and pressure-based measurements." International Journal of Engine Research 4, no. 2 (April 1, 2003): 61–86. http://dx.doi.org/10.1243/146808703321533240.
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A recently developed spark emission spec-troscopy technique has been used to measure the effects of fuel injection timing, spark timing and intake swirl level on the individual-cycle fuel concentration at the spark gap in a wall-guided spark ignited direct injection (SIDI) engine. The fuel-concentration measurements were made simultaneously with measurements of individual-cycle spark discharge energy and cylinder pressure. Endoscopic imaging of the fuel spray and high-speed imaging of combustion (both broadband and spectrally resolved) augment these quantitative data. For optimum engine operation, the fuel-air equivalence ratio at the spark gap just after spark breakdown is rich on average (〈φ〉 ≈1.4–1.5) and varies widely from cycle to cycle (∼25 per cent). The evolution with crank angle of the mean equivalence ratio and its cycle-to-cycle fluctuations are correlated with the cylinder pressure, heat release and imaging data to provide insights into fuel transport and mixture preparation that are important to understanding and optimizing ignition and combustion in SIDI engines. For example, causes of misfires and partial burns have been determined.
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Marikatti, Mahantesh, N. R. Banapurmath, V. S. Yaliwal, Y. H. Basavarajappa, Manzoore Elahi M. Soudagar, Fausto Pedro García Márquez, MA Mujtaba, et al. "Hydrogen Injection in a Dual Fuel Engine Fueled with Low-Pressure Injection of Methyl Ester of Thevetia Peruviana (METP) for Diesel Engine Maintenance Application." Energies 13, no. 21 (October 29, 2020): 5663. http://dx.doi.org/10.3390/en13215663.
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The present work is mapped to scrutinize the consequence of biodiesel and gaseous fuel properties, and their impact on compression-ignition (CI) engine combustion and emission characteristics in single and dual fuel operation. Biodiesel prepared from non-edible oil source derived from Thevetia peruviana belonging to the plant family of Apocynaceaeis. The fuel has been referred as methyl ester of Thevetia peruviana (METP) and adopted as pilot fuel for the effective combustion of compressed gaseous fuel of hydrogen. This investigation is an effort to augment the engine performance of a biodiesel-gaseous fueled diesel engine operated under varied engine parameters. Subsequently, consequences of gas flow rate, injection timing, gas entry type, and manifold gas injection on the modified dual-fuel engine using conventional mechanical fuel injections (CMFIS) for optimum engine performance were investigated. Fuel consumption, CO, UHC, and smoke formations are spotted to be less besides higher NOx emissions compared to CMFIS operation. The fuel burning features such as ignition delay, burning interval, and variation of pressure and heat release rates with crank angle are scrutinized and compared with base fuel. Sustained research in this direction can convey practical engine technology, concerning fuel combinations in the dual fuel mode, paving the way to alternatives which counter the continued fossil fuel utilization that has detrimental impacts on the climate.
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Ismael, Mhadi Abaker, Morgan Ramond Heikal, and Masri Ben Baharoom. "Spray Characteristics of Diesel-CNG Dual Fuel Jet Using Schlieren Imaging Technique." Applied Mechanics and Materials 663 (October 2014): 58–63. http://dx.doi.org/10.4028/www.scientific.net/amm.663.58.
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Natural gas is a low cost fuel with high availability in nature. However, it cannot be used by itself in conventional diesel engines due to its low flame speed and high ignition temperature. The addition of a secondary fuel to enhance the mixture formation and combustion process facilitate its wider use as an alternative fuel. An experimental study was performed to investigate the diesel-CNG dual fuel jet characteristics such as: jet tip penetration, jet cone angle and jet tip velocity. A constant-volume optical chamber was designed to facilitate maximum optical access for the study of the jet macroscopic characteristics at different injection pressures and temperatures. The bottom plate of the test rig was made of aluminum (piston material) and it was heated up to 500 K at ambient pressure. An injector driver was used to control the single-hole nozzle diesel injector combined with a natural gas injector. The injection timing of both injectors were synchronized with a camera trigger. Macroscopic properties of diesel and diesel-CNG dual fuel jets were recorded with a high speed camera using the Schlieren imaging technique and associated image processing. Measurements of the jet characteristics of diesel and diesel-CNG dual fuel are compared together under evaporative and non-evaporative conditions as well as different injection pressures are presented in this paper.
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Raghu, P., N. Nallusamy, and Pitchandi Kasivisvanathan. "Spray Characteristics of Diesel and Biodiesel Fuels for Various Injection Timings under Non Evaporating Conditions." Applied Mechanics and Materials 787 (August 2015): 682–86. http://dx.doi.org/10.4028/www.scientific.net/amm.787.682.
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Fuel spray and atomization characteristics play a vital role in the performance of internal combustion engines. Petroleum fuels are expected to be depleted within a few decades, finding alternative fuels that are economically viable to replace the petroleum fuel has attracted much research attention. In this work spray characteristics such as spray tip penetration, spray cone angle and spray area were investigated for Karanja oil methyl ester (KOME), Jatropha oil methyl ester (JOME) and diesel fuel. The KOME and JOME sprays were characterized and compared with diesel sprays at different injection timings. The macroscopic spray properties were acquired from the images captured by a high speed video camera employing shadowgraphic and image processing techniques in a spray chamber. The experimental results showed that biodiesel fuels had different features compared with diesel fuel after start of injection (ASOI). Longer spray tip penetration, larger spray area and smaller spray cone angle were observed for biodiesel (JOME, KOME) due to its higher density and viscosity than that of diesel fuel.
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Bibic, Dzevad, Ivan Filipovic, Ales Hribernik, and Boran Pikula. "Investigation into the effect of different fuels on ignition delay of M-type diesel combustion process." Thermal Science 12, no. 1 (2008): 103–14. http://dx.doi.org/10.2298/tsci0801103b.
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An ignition delay is a very complex process which depends on a great number of parameters. In practice, definition of the ignition delay is based on the use of correlation expressions. However, the correlation expressions have very often limited application field. This paper presents a new correlation which has been developed during the research project on the direct injection M-type diesel engine using both the diesel and biodiesel fuel, as well as different values of a static injection timing. A dynamic start of injection, as well as the ignition delay, is defined in two ways. The first approach is based on measurement of a needle lift, while the second is based on measurement of a fuel pressure before the injector. The latter approach requires calculation of pressure signals delay through the fuel injection system and the variation of a static advance injection angle changing. The start of a combustion and the end of the ignition delay is defined on the basis of measurements of an in-cylinder pressure and its point of separation from a skip-fire pressure trace. The developed correlation gives better prediction of the ignition delay definition for the M-type direct injection diesel engine in the case of diesel and biodiesel fuel use when compared with the classic expression by the other authors available in the literature.
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Pham, Van Chien, Jae-Hyuk Choi, Beom-Seok Rho, Jun-Soo Kim, Kyunam Park, Sang-Kyun Park, Van Vang Le, and Won-Ju Lee. "A Numerical Study on the Combustion Process and Emission Characteristics of a Natural Gas-Diesel Dual-Fuel Marine Engine at Full Load." Energies 14, no. 5 (March 1, 2021): 1342. http://dx.doi.org/10.3390/en14051342.
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This paper presents research on the combustion and emission characteristics of a four-stroke Natural gas–Diesel dual-fuel marine engine at full load. The AVL FIRE R2018a (AVL List GmbH, Graz, Austria) simulation software was used to conduct three-dimensional simulations of the combustion process and emission formations inside the engine cylinder in both diesel and dual-fuel mode to analyze the in-cylinder pressure, temperature, and emission characteristics. The simulation results were then compared and showed a good agreement with the measured values reported in the engine’s shop test technical data. The simulation results showed reductions in the in-cylinder pressure and temperature peaks by 1.7% and 6.75%, while NO, soot, CO, and CO2 emissions were reduced up to 96%, 96%, 86%, and 15.9%, respectively, in the dual-fuel mode in comparison with the diesel mode. The results also show better and more uniform combustion at the late stage of the combustions inside the cylinder when operating the engine in the dual-fuel mode. Analyzing the emission characteristics and the engine performance when the injection timing varies shows that, operating the engine in the dual-fuel mode with an injection timing of 12 crank angle degrees before the top dead center is the best solution to reduce emissions while keeping the optimal engine power.
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Hsu, B. D., G. L. Confer, and Z. J. Shen. "Progress on the Investigation of Coal-Water Slurry Fuel Combustion in a Medium-Speed Diesel Engine: Part 5—Combustion Studies." Journal of Engineering for Gas Turbines and Power 114, no. 3 (July 1, 1992): 515–21. http://dx.doi.org/10.1115/1.2906619.
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In the GE 7FDL single-cylinder research diesel engine, coal-water slurry (CWS) fuel combustion optimization studies were conducted using electronically controlled CWS and pilot accumulator injectors. The most important performance parameters of peak firing pressure, combustion efficiency (coal burnout), and specific fuel comsumption were evaluated in relationship to CWS and pilot injection timing, CWS injector hole size, shape, and number, CWS fuel injection spray angles and injection pressure. Heat release diagrams, as well as exhaust samples (gaseous and particulate), were analyzed for each case. Interesting effects of fuel spray impingement and CWS fuel “Delayed Ignition” were observed. With the engine operating at 2.0 MPa IMEP and 1050 rpm, it was able to obtain over 99.5 percent combustion efficiency while holding the cylinder firing pressure below 17 MPa and thermal efficiency equivalent to diesel fuel operation.
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K., Vijaya, Shailesh Palaparty, Raghavan Srinivasa, and Ravi Kumar Puli. "Investigations on performance of diesel engine by varying injection timings with design modification on piston crown." World Journal of Engineering 15, no. 5 (October 1, 2018): 562–66. http://dx.doi.org/10.1108/wje-11-2017-0348.
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Purpose Investigations are carried out with the aim of improving performance of a diesel engine with the design modification on piston crown to stimulate the uniform combustion by inducing turbulence in the incoming charge. Design/methodology/approach A stirrer is introduced at the top of the piston so as to inculcate more turbulence to the incoming charge by improving the rate of fuel vaporization. Whirling motion is created in the combustible mixture by providing rotating blades on the cavity/bowl of the reciprocating piston head. By putting a simple link mechanism, the oscillatory motion of connecting rod will rotate the blade by an angle of 60°. Findings The investigations are carried out with and without swirl piston at 17.5 compression ratio and 200 bar injection pressure by varying injection timings. Originality/value Finally, the result shows that by using the modified piston, nearly 3 per cent of efficiency increased and 31 per cent of NOx emissions are reduced compared to that of a normal piston with 80 per cent load at standard injection timing.
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Dond, Dipak Kisan, and Nitin P. Gulhane. "Optimization of combustion parameters for CRDI small single cylinder diesel engine by using response surface method." Journal of Mechanical Engineering and Sciences 16, no. 1 (March 23, 2022): 8730–42. http://dx.doi.org/10.15282/jmes.16.1.2022.07.0690.
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Limited fossil fuel’s reservoir capacity and pollution caused by them are the big problem today in the world. The small diesel engine, working with a conventional fuel injection system was the major contributor to this. The current study represented a statistical investigation of such a small diesel engine. A mechanical fuel injection system of the small diesel engine was retofitted with a simple version of the electronic common rail diesel injection (CRDI) system in the present study. The effect of combustion parameters such as compression ratio (CR), injection pressure (IP) and start of injection timing (IT) was considered in the study. The study was performed to optimize these parameters with respect to performance and emission aspects. The reduction in parameters such as carbon monoxide (CO), nitrogen oxides (NOx), smoke and hydrocarbon (HC) from engine exhaust gases were considered in the emission aspect. Improve brake thermal efficiency (BTE) and fuel economy was considered in the performance aspect. The response surfaced method (RSM) was used to optimise these combustion parameters. The regression equations were obtained for measurable performance and emission parameters using the RSM model. The surface plots derived from the regression equations were used to analyse the effect of considered combustion parameters. Diesel injected at a pressure 600 bar, with retarded injection timing 15° crank angle (CA) before top dead center (bTDC) and compression ratio set at 15 was found to be optimum for this CRDI small diesel engine. The further validation of optimum parameters was done by conducting a confirmatory test on the engine. The maximum error in prediction was found to be 2.7%, which shows the validation of the RSM model.
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Chan, S. H. "Thermodynamics in a turbocharged direct injection diesel engine." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 212, no. 1 (January 1, 1998): 11–24. http://dx.doi.org/10.1243/0954407981525768.
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Software has been developed for the calculation of the thermodynamic cycle and the entropy changes in a turbocharged, direct injection, diesel engine based upon the measured cylinder pressure and a shaft encoder output. Assumptions of homogeneous mixture and equilibrium thermodynamic properties are made for the products of combustion and the temporal variation in the fluid thermodynamic state is followed in a quasi-steady manner through a series of adjacent equilibrium states, each separated by finite intervals of one degree crank angle (1°CA). The thermodynamic properties are calculated by either of two equivalent formulations — equilibrium constants or minimization of Gibbs free energy, and are expressed in algebraic equations for the partial derivative of internal energy and gas constant with respect to temperature, pressure and equivalence ratio. The effect of the engine operating conditions on the thermodynamic cycle is studied. Results show that the dynamic fuel injection timing and hence the ignition delay are strongly influenced by the operating conditions, and this explains the reasons for incorporating a fuel injection control system in modern vehicular engines for the optimization of the engine combustion cycle.
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Wang, Xinyan, Jun Ma, and Hua Zhao. "Analysis of mixture formation process in a two-stroke boosted uniflow scavenged direct injection gasoline engine." International Journal of Engine Research 19, no. 9 (October 17, 2017): 927–40. http://dx.doi.org/10.1177/1468087417736451.
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The two-stroke engine has the great potential for aggressive engine downsizing and downspeeding because of its double firing frequency. For a given torque, it is characterized with a lower mean effective pressure and lower peak in-cylinder pressure than a four-stroke counterpart. In order to explore the potential of two-stroke cycle while avoiding the drawbacks of conventional ported two-stroke engines, a novel two-stroke boosted uniflow scavenged direct injection gasoline engine was proposed and designed. In order to achieve the stable lean-burn combustion in the boosted uniflow scavenged direct injection gasoline engine, the mixture preparation, especially the fuel stratification around the spark plug, should be accurately controlled. As the angled intake scavenge ports produce strong swirl flow motion and complex transfer between the swirl and tumble flows in the two-stroke boosted uniflow scavenged direct injection gasoline engine, the interaction between the in-cylinder flow motions and the direct injection and its impact on the charge preparation in the boosted uniflow scavenged direct injection gasoline engine are investigated in this study by three-dimensional computational fluid dynamics simulations. Both the single injection and split injections are applied and their impact on the mixture formation process is investigated. The start of injection timing and split injection ratio are adjusted accordingly to optimize the charge preparation for each injection strategy. The results show that the strong interaction between the fuel injection and in-cylinder flow motions dominates the mixture preparation in the boosted uniflow scavenged direct injection gasoline engine. Compared to the single injection, the split injection shows less impact on the large-scale flow motions. Good fuel stratification around the spark plug was obtained by the late start of injection timings at 300 °CA/320 °CA with an equal amount in each injection. However, when a higher tumble flow motion is produced by the eight scavenge ports’ design, a better fuel charge stratification can be achieved with the later single injection at start of injection of 320 °CA.
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Dalha, Ibrahim B., Mior A. Said, Zainal A. Abdul Karim, and Salah E. Mohammed. "An Experimental Investigation on the Influence of Port Injection at Valve on Combustion and Emission Characteristics of B5/Biogas RCCI Engine." Applied Sciences 10, no. 2 (January 8, 2020): 452. http://dx.doi.org/10.3390/app10020452.
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High unburned hydrocarbon (UHC) and carbon monoxide (CO) emissions, on account of the premixed air-fuel mixture entering the crevices and pre-mature combustion, are setbacks to reactivity-controlled compression ignition (RCCI) combustion at a low load. The influence of direct-injected B5 and port injection of biogas at the intake valve was, experimentally, examined in the RCCI mode. The port injection at the valve was to elevate the temperature at low load and eliminate premixing for reduced pre-mature combustion and fuel entering the crevices. An advanced injection timing of 21° crank angle before top dead centre and fraction of 50% each of the fuels, were maintained at speeds of 1600, 1800 and 2000 rpm and varied the load from 4.5 to 6.5 bar indicated mean effective pressure (IMEP). The result shows slow combustion as the load increases with the highest indicated thermal efficiency of 36.33% at 5.5 bar IMEP. The carbon dioxide and nitrogen oxides emissions increased, but UHC emission decreased, significantly, as the load increases. However, CO emission rose from 4.5 to 5.5 bar IMEP, then reduced as the load increases. The use of these fuels and biogas injection at the valve were capable of averagely reducing the persistent challenge of the CO and UHC emissions, by 20.33% and 10% respectively, compared to the conventional premixed mode.
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Ganapathy, Thirunavukkarasu, Parkash Gakkhar, and Krishnan Murugesan. "An analytical and experimental study of performance on jatropha biodiesel engine." Thermal Science 13, no. 3 (2009): 69–82. http://dx.doi.org/10.2298/tsci0903069g.
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Biodiesel plays a major role as one of the alternative fuel options in direct injection diesel engines for more than a decade. Though many feed stocks are employed for making biodiesel worldwide, biodiesel derived from domestically available non-edible feed stocks such as Jatropha curcas L. is the most promising alternative engine fuel option especially in developing countries. Since experimental analysis of the engine is pricey as well as more time consuming and laborious, a theoretical thermodynamic model is necessary to analyze the performance characteristics of jatropha biodiesel fueled diesel engine. There were many experimental studies of jatropha biodiesel fueled diesel engine reported in the literature, yet theoretical study of this biodiesel run diesel engine is scarce. This work presents a theoretical thermodynamic study of single cylinder four stroke direct injection diesel engine fueled with biodiesel derived from jatropha oil. The two zone thermodynamic model developed in the present study computes the in-cylinder pressure and temperature histories in addition to various performance parameters. The results of the model are validated with experimental values for a reasonable agreement. The variation of cylinder pressure with crank angle for various models are also compared and presented. The effects of injection timing, relative air fuel ratio and compression ratio on the engine performance characteristics for diesel and jatropha biodiesel fuels are then investigated and presented in the paper.
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Alkidas, A. C. "Combustion Characteristics of a Single-Cylinder Open-Chamber Diesel Engine." Journal of Engineering for Gas Turbines and Power 109, no. 4 (October 1, 1987): 419–25. http://dx.doi.org/10.1115/1.3240057.
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The combustion characteristics of an open-chamber diesel engine were examined by means of heat-release analysis and flame luminosity measurements. Increasing the load was found to decrease premixed burning and correspondingly to increase diffusion burning. During most of the diffusion combustion the burning rate of the fuel appeared to be directly proportional to the amount of unburned fuel present in the cylinder. The duration of heat release in crank-angle degrees increased linearly with load and, in general, increased with decreasing engine speed and retarded injection timing. The measured duration of flame luminosity was significantly longer than the calculated duration of heat release, which suggested that emission of radiation continued long after the heat-release reactions ceased.
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Guo, Peng Jiang, Xi Yan Gao, and Yun Bang Tang. "Analysis of Combustion Characteristics and Influencing Factors of Space Dispersed Double-Wall-Jet Combustion System." Advanced Materials Research 308-310 (August 2011): 1302–13. http://dx.doi.org/10.4028/www.scientific.net/amr.308-310.1302.
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Based on the ideas of wall-guiding-spray and spatial dispersion, A new type of diesel engine double-wall-jet combustion system is designed. The effect of speed, load and injection condition on the double-wall-jet combustion system is researched by testing, on the double-wall-jet combustion system, the combustion modes for whole working condition is analyzed, the comparison of combustion and performance between the original machine with the new one is carried out. The results showed that: Instantaneous heat release rate of double-wall-jet combustion system shows a single peak. As the speed increases, the corresponding crank angle of ignition retards, the peak outbreak pressure increases and then decreases, the peak instantaneous heat release rate, the peak average temperature, the peak cylinder pressure rise ratio, and the cumulative heat release per unit mass of working gas is reduced. As the load increases, the corresponding crank angles of peak cylinder pressure and gravity center of heat release rate are postponed. With the load increasing, the ignition crank angle corresponds early at low speed, and the ignition point does not change significantly with the load at high speed. The effect of the injector hole diameter/number on the cylinder pressure and instantaneous heat release rate curve is not significant at high speed and large loads, but at low speed and large loads is significant. Cylinder pressure of 6-Φ21 injector is higher than 5-Φ25, the instantaneous heat release rate of 6-Φ21 injector has a trend of a single peak, the instantaneous heat release rate of 5-Φ25 injector has a trend of a double peak and the focus of the heat release rate postponed. With the advancing of injection timing, the ignition crank angle and combustion phase advances, the peak cylinder pressure increases. Injection pressure has little effect on the combustion characteristics. By comparison with the original machine, while maintaining the power performance of the same circumstances, the cylinder pressure and NOx emissions of double-wall-jet engine are reduced in degree, fuel consumption rate is not almost changed, and the same plane rather, smoke intensity is improved at low speed, smoke intensity at high speed smoke high-speed only deteriorates of 0.2-0.3 BSU.
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Lebedevas, Sergejus, Saugirdas Pukalskas, and Vygintas Daukšys. "MATHEMATICAL MODELLING OF INDICATIVE PROCESS PARAMETERS OF DUAL-FUEL ENGINES WITH CONVENTIONAL FUEL INJECTION SYSTEM." Transport 35, no. 1 (March 16, 2020): 57–67. http://dx.doi.org/10.3846/transport.2020.12212.
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Modern engine research uses multi-dimensional Mathematical Models (MMs) that are applicable to multi-fuel engines. However, their use involves the availability of detailed technical data on the design and characteristics of the engine, which is not always possible. The use of a one-dimensional MM is more expedient for the prediction of engine parameters, but their application for this purpose has not yet been sufficiently investigated. This publication presents the results of numerical studies evaluating the application of a one-dimensional MM with bi-phase Vibe combustion laws for dual-fuel (DF) Diesel (D) and Natural Gas (NG) engine power parameters. The motor test results of a high-speed 4ČN79.5/95.5 Diesel Engine (DE) with a conventional fuel injection system were used as adequacy criteria. The engines were operated with D100 and DF D20/NG80, in high- (HLM), medium- (MLM), and low- (LLM) load modes, and the angle of Diesel-fuel Injection Timing (DIT) was changed from −1 to −13 °CA in the Before Top Dead Center (BTDC) range. Modelling of the single-phase Vibe combustion law has limited applicability for efficient use only in HLM (with an error of 7%). In the MLM and LLM regimes, owing to non-compliance with real bi-phasic combustion with a strongly extended NG diffusive second phase, the modelling error is 50%. Individual MM matching in MLM and LLM in a DF D20/NG80 experiment detected a burn time increase from between 45 and 50 °CA, to 110 and 200 °CA, respectively. Limited use of the one-dimensional MM in the evaluation of DF engine performance has been identified. When comparing a one-dimensional MM with experimental data, a bi-phase law of heat release characteristic should be considered for better coincidence. In addition, individual MM matching with an experiment on each engine load mode ensured acceptable accuracy in testing and optimising the parameters of the indicator process, including DIT.
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Gu, Yuanqi, Liyun Fan, Jianyu Zhang, and Yun Bai. "Multi-objective Optimization of High-speed Solenoid Valve for Biodiesel Electronic Unit Pump." Current Chinese Science 2, no. 1 (February 2022): 38–47. http://dx.doi.org/10.2174/2210298101666211209112854.
Full textAbstract:
Background: A larger response delay of a high-speed solenoid valve will cause inaccurate fuel injection timing and imprecise cycle injection quantity, resulting in diesel engine emission and increased fuel consumption. Objective: Biodiesel as an ideal alternative fuel has exceptional advantages in energy conservation, emission reduction, and low-carbon environmental protection; however, matching with Electronic Unit Pump (EUP) and its impacts on solenoid valve operation need to be further studied. Methods: In the present work, a numerical model of EUP fueled with biodiesel was established in an AMESim environment, which was validated by the experiment. Then, combined with the Design of Experiments (DOE) method, key parameters influencing the solenoid valve response delay were predicted: armature residual air gap, spring preload, poppet valve half-angle, valve needle diameter, and poppet valve diameter. Results: taking the response delay time of solenoid valve as targets, multi-objective optimization model for high-speed solenoid valve was established using NSGA-II (non-dominated sorting genetic algorithm-II) genetic algorithm in modeFRONTIER platform. Conclusion: The optimized results showed that the delay time of the solenoid valve closing is reduced by 6%, the opening delay time is reduced by 20.8%, the injection pressure peak is increased by 1.8MPa, which is beneficial to accurate injection quantity and the application of biodiesel in diesel engines.
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KOWALSKI, Jerzy. "The CFD analysis of influence the start of fuel injection (SOI) on combustion parameters and exhaust gas composition of the marine 4-stroke engine." Combustion Engines 177, no. 2 (May 1, 2019): 40–45. http://dx.doi.org/10.19206/ce-2019-207.
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The paper presents a theoretical analysis of the impact of injection timing on the parameters of the combustion process and the com-position of exhaust gas from a 4-stroke engine designed to shipbuilding. The analysis was carried out based on a three-dimensional multi-zone model of the combustion process. This model has been prepared on the basis of properties of the research facility. The input data to the model were obtained through laboratory tests. Results of calculations showed that the change of the start of injection angle (SOI) from the value of 14 degrees before TDC to 22 degrees before TDC results in changes in the combustion rate and thus an increase in the temperature of the combustion process as well as the increase of nitric oxides fraction in the exhaust gas. Simultaneously the maximum combustion pressure increases also.
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Dai, Xingyi (Hunter), Satbir Singh, Sundar R. Krishnan, and Kalyan K. Srinivasan. "Numerical study of combustion characteristics and emissions of a diesel–methane dual-fuel engine for a wide range of injection timings." International Journal of Engine Research 21, no. 5 (June 22, 2018): 781–93. http://dx.doi.org/10.1177/1468087418783637.
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Computational fluid dynamics simulations are performed to investigate the combustion and emission characteristics of a diesel/natural gas dual-fuel engine. The computational fluid dynamics model is validated against experimental measurements of cylinder pressure, heat release rate, and exhaust emissions from a single-cylinder research engine. The model predictions of in-cylinder diesel spray distribution and location of diesel ignition sites are related to the behavior observed in measured and predicted heat release rate and emissions. Various distributions of diesel fuel inside the combustion chamber are obtained by modifying the diesel injection timing and the spray included angle. Model predictions suggest that the distribution of diesel fuel in the combustion chamber has a significant impact on the characteristics of heat release rate, explaining experimental observations. Regimes of combustion in the dual-fuel engine are identified. Turbulent flame speed calculations, premixed turbulent combustion regime diagram analysis, and high-temperature front propagation speed estimation indicated that the dual-fuel combustion in this engine was supported by successive local auto-ignition and not by turbulent flame propagation.
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Guan, Wei, Hua Zhao, Zhibo Ban, and Tiejian Lin. "Exploring alternative combustion control strategies for low-load exhaust gas temperature management of a heavy-duty diesel engine." International Journal of Engine Research 20, no. 4 (February 7, 2018): 381–92. http://dx.doi.org/10.1177/1468087418755586.
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The employment of aftertreatment systems in modern diesel engines has become indispensable to meet the stringent emissions regulations. However, a minimum exhaust gas temperature of approximately 200 °C must be reached to initiate the emissions control operations. Low-load engine operations usually result in relatively low exhaust gas temperature, which lead to reduced or no exhaust emissions conversion. In this context, this study investigated the use of different combustion control strategies to explore the trade-off between exhaust gas temperature, fuel efficiency, and exhaust emissions. The experiments were performed on a single-cylinder heavy-duty diesel engine at a light load of 2.2 bar indicated mean effective pressure. Strategies including the late intake valve closing timing, intake throttling, late injection timing (Tinj), lower injection pressure (Pinj), and internal exhaust gas recirculation and external exhaust gas recirculation were investigated. The results showed that the use of external exhaust gas recirculation and lower Pinj was not effective in increasing exhaust gas temperature. Although the use of late Tinj could result in higher exhaust gas temperature, the delayed combustion phase led to the highest fuel efficiency penalty. Intake throttling and internal exhaust gas recirculation allowed for an increase in exhaust gas temperature at the expense of higher fuel consumption. In comparison, late intake valve closure strategy achieved the best trade-off between exhaust gas temperature and net indicated specific fuel consumption, increasing the exhaust gas temperature by 52 °C and the fuel consumption penalty by 5.3% while reducing nitrogen oxide and soot emissions simultaneously. When the intake valve closing timing was delayed to after −107 crank angle degree after top dead centre, however, the combustion efficiency deteriorated and the HC and CO emissions were significantly increased. This could be overcome by combining internal exhaust gas recirculation with late intake valve closure to increase the in-cylinder combustion temperature for a more complete combustion. The results demonstrated that the ‘late intake valve closure + internal exhaust gas recirculation’ strategy can be the most effective means, increasing the exhaust gas temperature by 62 °C with 4.6% fuel consumption penalty. Meanwhile, maintaining high combustion efficiency as well as low HC and CO emissions of diesel engines.
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Mohamad, Taib Iskandar, and How Heoy Geok. "Combustion Characteristics of Compressed Natural Gas in a Direct Microchannel-Injection Engine under Various Operating Conditions." Applied Mechanics and Materials 315 (April 2013): 793–98. http://dx.doi.org/10.4028/www.scientific.net/amm.315.793.
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The combustion characteristics of compressed natural gas (CNG) in a direct microchannel-injection engine under various operating conditions were investigated. In this study, a novel idea for direct CNG microchannel injection was realized with spark plug fuel injector (SPFI). It is a device developed to convert engine to CNG direct injection (DI) operation with minimal cost and technical simplicity. It was installed and tested on a Ricardo E6 single cylinder engine with compression ratio of 10.5:1 without modification on the original engine structure. The engine test was carried out under various operation conditions at 1100 rpm. Burning rates of CNG were measured using normalized combustion pressure method by which the normalized pressure rise due to combustion is equivalent to the mass fraction burned (MFB) at the specific crank angle. The results showed that the MFB of CNG direct injection is substantially faster but initially slower than the ones of port injection. The optimal fuel injection and ignition timings are 190 °CA ATDC and 25 °CA BTDC respectively. The optimal injection pressure was 6 MPa. Combustion durations were not changed with different injection pressures but ignition delay was affected. There was no direct correlation between injection pressure and ignition delay which is most probably due to the effect of charge flow difference. Changing mixture stoichiometry affects the magnitude of ignition delay. Combustion duration, on the other hand increases with leaner mixture.
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Xiao, Min, and Hui Chen. "A Study on Reducing the NOx Emission of the L21/31 Medium-Speed Marine Diesel Engine for IMO Tier Emission Legislation." Applied Mechanics and Materials 291-294 (February 2013): 1920–24. http://dx.doi.org/10.4028/www.scientific.net/amm.291-294.1920.
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The KIVA-3V program was used to make numerical simulation for L21/31 type of medium-speed marine diesel engine about the NOx emissions and the affection of NOx changing process on different variable parameters under the Tier Ⅱstandard. On this basis, a discussion towards the NOx emission of the model fueling with dimethyl ether (DME) to meet the Tier Ⅲ standard is offered. The results show that reducing the intake temperature, load and speed, postponing the fuel injection timing and intake lag angle properly can decrease the NOx emissions within the limits of NOx in TierⅡ standard. Comparing the results of the numerical simulation of DME and diesel fuel, the NOx emission of the former one is 60.85% of the latter one, and the NOx emission of changing variable parameters on DME engine is 35.56% of the original type of diesel engine, very close to the Tier Ⅲ.
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Storm, Xiaoguo, Hoang Khac Nguyen, Amin Modabberian, Kai Zenger, and Jari Hyvönen. "Model-based on-board post-injection control development for marine diesel engine." Open Engineering 11, no. 1 (January 1, 2021): 1160–69. http://dx.doi.org/10.1515/eng-2021-0115.
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Abstract The increasing demands for reducing fuel consumption and emissions in contemporary technology solutions lead to the use of more sensors, actuators, and control applications. With this increasing engine complexity, the feedback design is complex due to the coupling between inputs and combustion parameters. To be able to design the controller systematically, model predictive control (MPC) comes to the scope because of its advantages in the design of multi-input multi-output (MIMO) systems, especially with its constraints handling ability and performance in simultaneously optimizing the engine fuel efficiency and emission reduction. Multi-injection is one of the promising techniques for achieving better engine performance. In this work, post-injection control is implemented utilizing MPC MIMO strategy with the target of exploring the possibility of reducing emissions and improving engine efficiency by controlling post-injection duration and injection timing. The workflow of the MPC controller design from control-oriented model (COM) establishing to MPC problem formation and solution methodology is discussed in this work. Moreover, one contribution from this work is the different implementation angle when compared with the state-of-the-art approaches, where the MPC controller is implemented purely by Matlab Simulink to enable the rapid control prototyping design. The simulation result demonstrated the ability of the controller’s tracking performance and showed a preliminary step towards the nonlinear combustion model-based multi-injection MPC design. The systematic model-based controller framework developed in this work can be applied to other control applications and enables a fast path from design to test.
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Hamdi, Fathi, Senda Agrebi, Mohamed Salah Idrissi, Kambale Mondo, Zeineb Labiadh, Amsini Sadiki, and Mouldi Chrigui. "Impact of Spray Cone Angle on the Performances of Methane/Diesel RCCI Engine Combustion under Low Load Operating Conditions." Entropy 24, no. 5 (May 5, 2022): 650. http://dx.doi.org/10.3390/e24050650.
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The behaviors of spray, in Reactivity Controlled Combustion Ignition (RCCI) dual fuel engine and subsequent emissions formation, are numerically addressed. Five spray cone angles ranging between 5° and 25° with an advanced injection timing of 22° Before Top Dead Center (BTDC) are considered. The objective of this paper is twofold: (a) to enhance engine behaviors in terms of performances and consequent emissions by adjusting spray cone angle and (b) to outcome the exergy efficiency for each case. The simulations are conducted using the Ansys-forte tool. The turbulence model is the Renormalization Group (RNG) K-epsilon, which is selected for its effectiveness in strongly sheared flows. The spray breakup is governed by the hybrid model Kelvin–Helmholtz and Rayleigh–Taylor spray models. A surrogate of n-heptane, which contains 425 species and 3128 reactions, is used for diesel combustion modeling. The obtained results for methane/diesel engine combustion, under low load operating conditions, include the distribution of heat transfer flux, pressure, temperature, Heat Release Rate (HRR), and Sauter Mean Diameter (SMD). An exergy balance analysis is conducted to quantify the engine performances. Output emissions at the outlet of the combustion chamber are also monitored in this work. Investigations show a pressure decrease for a cone angle θ = 5° of roughly 8%, compared to experimental measurement (θ = 10°). A broader cone angle produces a higher mass of NOx. The optimum spray cone angle, in terms of exergy efficiency, performance, and consequent emissions is found to lie at 15° ≤ θ ≤ 20°.
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Golzari, Reza, Hua Zhao, Jonathan Hall, Mike Bassett, John Williams, and Richard Pearson. "Impact of intake port injection of water on boosted downsized gasoline direct injection engine combustion, efficiency and emissions." International Journal of Engine Research 22, no. 1 (April 8, 2019): 295–315. http://dx.doi.org/10.1177/1468087419832791.
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Introduction of ever more stringent emission regulations on internal combustion engines beyond 2020 makes it necessary for original equipment manufacturers to find cost-effective solutions to improve the combustion engine efficiency and decrease its emissions. Highly efficient combustion engines can benefit from technologies such as cooled external exhaust gas recalculation and water injection. Among these technologies water injection can be used as a promising method to mitigate knock and significantly reduce the CO2 emissions. This is particularly important in highly downsized boosted engines which run under much higher intake pressures and are more prone to knocking combustion. In addition to anti-knock behaviour, water injection is also an effective method for reducing NOx emissions and exhaust gas temperature at high loads, which can protect the turbine in turbocharged engines. This study shows the influence of intake port injection of water on efficiency and emissions of a boosted downsized single-cylinder gasoline direct-injection engine in detail. Six different steady-state speed and load combinations were selected to represent the conditions that knocking combustion start to occur. Water ratio sweep tests were performed to find out the optimum water/fuel ratio at each test point and the impact on the combustion and emissions. In addition to gaseous emissions, impact of water injection on particle emissions was also investigated in this study. The results show the net indicated efficiency improved significantly (by a maximum of around 5% at medium load and around 15% at high load) up to a maximum level by increasing the injected water mass. Improvement in efficiency was mainly due to the increased heat capacity of charge and cooling effect of the injected water evaporation which reduced the in-cylinder temperature and pressure. Thus, knock sensitivity was reduced and more advanced spark timings could be used, which shifted the combustion phasing closer to the optimum point. However, increasing the water/fuel ratio further (more than 1 at medium load and more than 1.5 at high load) deteriorated the combustion efficiency, prolonged the flame development angle and combustion duration, and caused a reduction in the net integrated area of the P-V diagram. Efficiency improvements were lower at higher engine speed (3000 r/min) as the knock sensitivity was already reduced intrinsically. In terms of other, harmful, non-CO2 emissions, water injection was effective in reducing the NOx emissions significantly (by a maximum of around 60%) but increased the HC emissions as the water/fuel ratio increased. The results also show a significant reduction in particle emissions by adding water to the mixture and advancing the spark timing at medium and high loads. In addition, water injection also reduced the exhaust gas temperature by around 80°C and 180°C at medium and high loads, respectively.