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2017-10-08
Technical Paper
2017-01-2301
Hongli Gao, Fujun Zhang, Wenwen Zeng, Tianpu Dong, Zhengkai Wang
Abstract The electronic control of direct injection fuel system, which could improve engine fuel efficiency, dynamics and engine emission performance through good atomization, precise control of fuel injection time and improvement of fuel-gas mixture, is the key technology to achieve the stratified combustion and lean combustion. In this paper, a direct injection injector that based on voice coil motor was designed aiming at the technical characteristics of one 800cc two-stroke cam-less engine. Prior to a one - dimensional simulation model of injector was established by AMEsim and the maximal fuel injection demand was met via the optimization of the main parameters of the injector, the structure of the voice coil motor was optimized by magnetic equivalent circuit method. After that, the maximal flow rate of the injector was verified by the injector bench test while the atomization characteristic of the injector was verified by using a high-speed camera.
2017-10-08
Technical Paper
2017-01-2303
Yan Wang, Xudong Wang, Zhen Zhang, Yong Wang, Guoxiu Li, Yusong Yu
Abstract Fuel spray impingement is a common phenomenon during the combustion processes of a DI diesel engine. When liquid droplets impinge on the hot surface of a combustion chamber, a complex heat transfer and mechanical interaction occur between the droplets and combustion chamber. This probably changes the surface topography and microstructure of the impact position. Based on the experimental method, the fuel spray phenomenon and conditions of a surface pit caused by droplet impingement were investigated. The experimental results indicate that the surface pit is formed under specific conditions, i.e., a specific droplet diameter and surface temperature. Scanning electron microscopy of the pit area shows that the microstructure of the pit changed from an original dense and smooth surface to a loose structure. The microstructure of the pit did not show a molten state. The concentration of metal and nonmetallic elements in the pit area changed significantly.
2017-10-08
Technical Paper
2017-01-2283
Anand Prabu Kalaivanan, Gnanasekaran Sakthivel
Abstract Electronic Fuel Injection Systems have revolutionised Fuel Delivery and Ignition timing in the past two decades and have reduced the Fuel Consumption and Exhaust Emissions, ultimately enhancing the Economy and Ecological awareness of the engines. But the ignition/injection timing that commands the combustion is mapped to a fixed predefined table which is best suited during the stock test conditions. However continuous real time adjustments by monitoring the combustion characteristics prove to be highly efficient and be immune to varying fuel quality, lack of transient performance and wear related compression losses. For developing countries, Automotive Manufacturers have been Tuning the Ignition/Injection timing Map assuming the worst possible fuel quality. Conventional knock control system focus on engine protection only and doesn't contribute much in improving thermal efficiency.
2017-10-08
Technical Paper
2017-01-2284
Haifei Zheng
Abstract The potential benefits of reheat burner placed between turbine stages for propulsion system have been recognized for nearly a century. Compared to the conventional non-reheat engines, the turbine inter-guide-vane burner (TIB) engines by using jet-swirl flow scheme (high-G loading) are shown to have a higher specific thrust with no or only small increase in thrust specific fuel consumption. But, it is a known fact that the G loading in the circumferential cavity is inversely proportional to the radius of the circumferential cavity. If one needs to scale this configuration for a larger spool of turbine components, the effeciency of the high G operation and obtained benefits on flame speed will reduce and hence the performance will de-grade.
2017-10-08
Technical Paper
2017-01-2286
A S Ramadhas, Punit Kumar Singh, Reji Mathai, Ajay Kumar Sehgal
Abstract Ambient temperature conditions, engine design, fuel, lubricant and fuel injection strategies influence the cold start performance of gasoline engines. Despite the cold start period is only a very small portion in the legislative emission driving cycle, but it accounts for a major portion of the overall driving cycle emissions. The start ability tests were carried out in the weather controlled transient dynamometer - engine test cell at different ambient conditions for investigating the cold start behavior of a modern generation multi-point fuel injection system spark ignition engine. The combustion data were analyzed for the first 200 cycles and the engine performance and emissions were analyzed for 300 s from key-on. It is observed that cumulative fuel consumption of the engine during the first 60 s of engine cold starting at 10 °C was 60% higher than at 25 °C and resulted in 8% increase in the value of peak speed of the engine.
2017-10-08
Technical Paper
2017-01-2288
Tianyuan Zhou, Changsheng Yao, Fuyuan Yang, Sun Jinwei
Abstract Low temperature combustion (LTC) is an advanced combustion mode, which can achieve low emissions of NOx and PM simultaneously, and keep relatively high thermal efficiency at the same time. However, one of the major challenges for LTC is the cold condition. In cold conditions, stable compression ignition is hard to realize, while thermal efficiency and emissions deteriorate, especially for gasoline or fuel with high octane number. This study presents using pressure sensor glow plugs (PSG) to realize Glow plug assisted compression ignition (GA-CI) at cold conditions. Further, a glow plug control unit (GPCU) is developed, a closed-loop power feedback control algorithm is introduced based on GPCU. In the experiment, engine coolant temperature is swept. Experimental results show that GA-CI has earlier combustion phases, larger combustion duration and higher in-cylinder pressure. And misfire is avoided, cycle-to-cycle variations are greatly reduced.
2017-10-08
Technical Paper
2017-01-2323
Lei Li, Kai Sun, Jianyu Duan
Abstract Butanol is a promising alcohol fuel. Previous studies on combustion and diesel engines showed different trends in sooting tendencies of the butanol isomers (n-butanol, iso-butanol, sec-butanol and tert-butanol).The impact of butanol isomers on the particulate emissions of GDI (Gasoline Direct Injection) engines, however, has not been reported. This work examines the combustion performance and particle number emissions of a GDI engine fueled with gasoline/butanol blends in steady state modes. Each isomer was tested at blend ratios from 10% to 50% by volume. Spark timings for all the fuels are set to obtain the maximum break torque (MBT), i.e. the MBT spark timings. Results show that the particle number concentration is reduced significantly with increasing butanol content for all the isomers.
2017-10-08
Technical Paper
2017-01-2282
Gen Chen, Wenxin Cai, Jianguang Zhou, Christian Spanner, Heribert Fuchs, Werner Schrei, Karl Weihrauch
Abstract A TGDI (turbocharged gasoline direct injection) engine is developed to realize both excellent fuel economy and high dynamic performance to guarantee fun-to-drive. In order to achieve this target, it is of great importance to develop a superior combustion system for the target engine. In this study, CFD simulation analysis, steady flow test and transparent engine test investigation are extensively conducted to ensure efficient and effective design. One dimensional thermodynamic simulation is firstly conducted to optimize controlling parameters for each representative engine operating condition, and the results serve as the input and boundary condition for the subsequent Three-dimensional CFD simulation. 3D CFD simulation is carried out to guide intake port design, which is then measured and verified on steady flow test bench.
2017-10-08
Technical Paper
2017-01-2290
Zhixin Sun, Shaoqing Yang, Xinyong Qiao, Zhiyuan Zhang
Abstract When operating at high elevation of 3700m (atmospheric pressure about 68 kPa), the combustion process of diesel engine deteriorates, and the engine performance declines significantly. In this paper, Isooctyl Nitrate(EHN) is blended into the diesel fuel as additive to improve the combustion process. The decomposition of Isooctyl Nitrate(EHN) is analyzed and its mechanism is studied through chemical kinetics. A series of tests were carried out on a single cylinder diesel engine to study the effects of EHN on diesel engine combustion with the low intake pressure of 68kPa. Results show that the generation of OH、 H、 HO2 and H2O2 in n-heptane cleavage reactions can be promoted by EHN. In both stages of low and high temperature, the decomposition of n-heptane is accelerated, which shortened the ignition delay period. Four kinds of fuel are studied by tests: diesel fuel, diesel fuel with 0.3%, 0.6% and 0.9% mass fraction EHN respectively.
2017-10-08
Technical Paper
2017-01-2322
Tankai Zhang, Karin Munch, Ingemar Denbratt
Abstract Reducing emissions and improving efficiency are major goals of modern internal combustion engine research. The use of biomass-derived fuels in Diesel engines is an effective way of reducing well-to-wheels (WTW) greenhouse gas (GHG) emissions. Moreover, partially premixed combustion (PPC) makes it possible to achieve very efficient combustion with low emissions of soot and NOx. The objective of this study was to investigate the effect of using alcohol/Diesel blends or neat alcohols on emissions and thermal efficiency during PPC. Four alcohols were evaluated: n-butanol, isobutanol, n-octanol, and 2-ethylhexanol. The alcohols were blended with fossil Diesel fuel to produce mixtures with low cetane numbers (26-36) suitable for PPC. The blends were then tested in a single cylinder light duty (LD) engine. To optimize combustion, the exhaust gas recirculation (EGR) level, lambda, and injection strategy were tuned.
2017-10-08
Technical Paper
2017-01-2327
Joonsik Hwang, Choongsik Bae, Chetankumar Patel, Avinash Kumar Agarwal, Tarun Gupta
Abstract Fuel atomization and air-fuel mixing processes play a dominant role on engine performance and emission characteristics in a direct injection compression ignition engine. Understanding of microscopic spray characteristics is essential to predict combustion phenomena. The present work investigated near nozzle flow and atomization characteristics of biodiesel fuels in a constant volume chamber. Waste cooking oil, Jatropha, and Karanja biodiesels were applied and the results were compared with those of conventional diesel fuel. The tested fuels were injected by a solenoid injector with a common-rail injection system. A high-speed camera with a long distance microscopic lens was utilized to capture the near nozzle flow. Meanwhile, Sauter mean diameter (SMD) was measured by a phase Doppler particle analyzer to compare atomization characteristics.
2017-10-08
Technical Paper
2017-01-2329
Xiao Ma, Yue Ma, Shuaishuai Sun, Shi-Jin Shuai, Zhi Wang, Jian-Xin Wang
Abstract Polyoxymethylene dimethyl ethers (PODEn) are promising alternative fuel candidates for diesel engines because they present advantages in soot reduction. This study uses a PODEn mixture (contains PODE3-6) from mass production to provide oxygen component in blend fuels. The spray combustion of PODEn-diesel bend fuels in a constant volume vessel was studied using high speed imaging, PLII-LEM and OH* chemiluminescence. Fuels of several blend ratios are compared with pure diesel. Flame luminance data show a near linear decrease tendency with the blend ratio increasing. The OH* images reveal that the ignition positions of all the cases have small differences, which indicates that using a low PODEn blend ratio of no more than 30% does not need significant adjustment in engine combustion control strategies. It is found that 30% PODEn blended with diesel (P30) can effectively reduce the total soot by approximately 68% in comparison with pure diesel.
2017-10-08
Technical Paper
2017-01-2332
Tamara Ottenwaelder, Stefan Pischinger
Abstract In order to reduce engine out CO2 emissions it is a main subject to find new alternative fuels out of renewable sources. For this paper, several fuels were selected which can be produced out of biomass or with hydrogen which is generated directly via electrolysis with electricity from renewable sources. All fuels are compared to conventional diesel fuel and two diesel surrogates. It is well known that there can be a large effect of fuel properties on mixture formation and combustion, which may result in a completely different engine performance compared to the operation with conventional diesel fuels. Mixture formation and ignition behavior can also largely affect the pollutant formation. The knowledge of the combustion behavior is also important to design new engine geometries or implement new calibrations for an existing engine. The fuel properties of the investigated fuels comprise a large range, for example in case of the derived cetane number, from below 30 up to 100.
2017-10-08
Technical Paper
2017-01-2335
Tiantian Yang, Tie Wang, Jing Qiao, Ji Gao, Yizhuo Feng, Dandan Sun
Abstract The F-T diesel made from coal by Fischer-Tropsch synthesis (F-T) can be used as a clean alternative fuel of diesel engine. To alleviate the drawback of high cost and low viscosity of F-T diesel, the Methanol-Biodiesel -F-T diesel multiple fuel (MBFT) was prepared by adding low-cost methanol and high-viscosity biodiesel as modifiers. Considering the immiscibility between alcohols and hydrocarbons, this paper carried out a series of stability tests and found that n-decanol was the optimum co-solvent of MBFT. The MBFTs blended by biodiesel with the volume fraction of 10% (10% vol.) and methanol with varying proportions of 0%, 5%, 10% and 15% vol. were denoted as M0, M5, M10 and M15, respectively. The increasing methanol proportion caused the increase of the oxygen content in the blended fuels and the reduction of heat value, surface tension and cetane number. The influence of methanol proportion on combustion characteristics of turbo-charging engine was studied.
2017-10-08
Technical Paper
2017-01-2338
Muhammad Saqib Akhtar, Shuaishuai Sun, Xiao Ma, Yitao Shen, Shi-Jin Shuai, Zhi Wang
Abstract Natural gas is one of the promising alternative fuels due to the low cost, worldwide availability, high knock resistance and low carbon content. Ignition quality is a key factor influencing the combustion performance in natural gas engines. In this study, the effect of pre-chamber geometry on the ignition process and flame propagation was studied under varied initial mixture temperatures and equivalence ratios. The pre-chambers with orifices in different shapes (circular and slit) were investigated. Schlieren method was adopted to acquire the flame propagation. The results show that under the same cross-section area, the slit pre-chamber can accelerate the flame propagation in the early stages. In the most of the cases, the penetration length of the flame jet and flame area development are higher in the early stages of combustion.
2017-10-08
Technical Paper
2017-01-2429
Felix Leach, Martin Davy, Adam Weall, Brian Cooper
Abstract Diesel engine designers often use swirl flaps to increase air motion in cylinder at low engine speeds, where lower piston velocities reduce natural in-cylinder swirl. Such in-cylinder motion reduces smoke and CO emissions by improved fuel-air mixing. However, swirl flaps, acting like a throttle on a gasoline engine, create an additional pressure drop in the inlet manifold and thereby increase pumping work and fuel consumption. In addition, by increasing the fuel-air mixing in cylinder the combustion duration is shortened and the combustion temperature is increased; this has the effect of increasing NOx emissions. Typically, EGR rates are correspondingly increased to mitigate this effect. Late inlet valve closure, which reduces an engine’s effective compression ratio, has been shown to provide an alternative method of reducing NOx emissions.
2017-10-08
Technical Paper
2017-01-2412
Dojoong Kim, Dong Hyeong Lee, Jong Wung Park, Soo Hyun Hwang, Wan Jae Jeon
Abstract This paper introduces a two-step variable valve actuation (VVA) mechanism equipped with an electronic switching system, which can be applied to OHC valve trains with end pivot rocker arms. The electronic switching system is driven by a dedicated solenoid and is not affected by the temperature or pressure of the engine oil. Therefore, not only can the dynamic stability be secured at the time of mode switching but the operation delay time can also be kept short enough. Several models of two-step VVA mechanisms were fabricated and the operability of the mechanism and switching system was experimentally confirmed. The two-step VVA mechanism developed in this study can also be used as a cylinder deactivation (CDA) system by assigning the lift of the low-speed cam to be zero. By attaching a roller to the portion of the rocker arm that is in contact with the base cam, the problem of pad wear, which is often present in CDA mechanism, is also fundamentally solved.
2017-10-08
Technical Paper
2017-01-2244
Shui Yu, Xiao Yu, Zhenyi Yang, Meiping Wang, Xiaoye Han, Jimi Tjong, Ming Zheng
The fuel efficiency improvement of gasoline engines can be achieved through lean burn and/or exhaust gas recirculation (EGR). However, the ignition of a diluted cylinder charge tends to be more diverged, owing to the slower ignition and combustion processes. The operable range of diluted combustion in gasoline engines is often limited, e.g. with lambda below 2.0 or EGR rate lower than 30%, owing to the deterioration in mixture ignitability and severe cyclic variations. In addition, the adoption of intensified cylinder charge motion requires further optimizations of ignition system, including the igniter geometric configurations and the temporal modulations over ignition energy delivery and spark discharge pattern. In this work, a variety of spark ignition approaches are investigated to improve the ignition of diluted gasoline engine under homogeneous mixture mode. A spatially distributed spark arcing control is realized based on a three-pole igniter.
2017-10-08
Technical Paper
2017-01-2242
Boyuan Wang, Zhi Wang, Changpeng Liu, Fubai Li, Yingdi Wang, Yunliang Qi, Xin He, Jianxin Wang
A new ignition method is proposed called flame accelerated ignition, which is realized by a flame acceleration tunnel set between the spark plug and the main chamber with annular spoilers inside. The investigation of flame accelerated ignition was experimentally accomplished on both a rapid compression machine with optical accessibility and a single-cylinder heavy duty engine. In rapid compression machine study, synchronous pressure sensing and high-speed photography were used with spark ignition cases tested for comparison. The results show that the combustion process is significantly accelerated by flame acceleration ignition. The combustion duration is shortened by more than 30% under all loads compared with spark ignition. According to the optical results, the axial speed of flame outside the flame acceleration tunnel reaches at least 30 m/s and shows positive correlation with load, which is over 10 times than that of conventional flame propagation caused by spark ignition.
2017-10-08
Technical Paper
2017-01-2245
Xianlin Ouyang, Ho Teng, Xiaochun zeng, Xuwei Luo, Tingjun Hu, Xianlong Huang, Jiankun Luo, Yongli Zhou
Atkinson cycle realized with a late intake valve closing (LIVC) and Miller cycle achieved with an early intake valve closing (EIVC) have been recognized as effective approaches for improving the gasoline engine fuel economy. In both Atkinson and Miller cycles, the engine can be designed with a higher geometric compression ratio for increasing the expansion work and the effective compression ratio is governed by the intake valve close (IVC) timing for the knock control. Duration of the intake event and IVC timing affect not only the pumping loss during the gas exchange, but also have strong influences on the friction torques of the intake cams and the turbulence intensities for the in-cylinder charge motion. The latter governs duration of combustion and EGR tolerance, both of which have impacts on the engine thermal efficiency.
2017-10-08
Technical Paper
2017-01-2248
Haichun Ding, Wenbin Zhang, Xiao Ma, Shi-Jin Shuai, Bin Zheng, Alex Cantlay, Vinod Natarajan, Zhang Song Zhan, Bin Liu
Gasoline direct injection (GDI) engine is now widely used due to its high fuel efficiency and low HC emission during cold start. However, high particle emission has become an inevitable challenge especially with injector deposits. In this paper, a 4-cylinder turbocharged GDI engine in Chinese market was selected and operated at 2000rpm and 3bar BMEP condition for 50 hours to accumulate injector deposits. The engine ignition angle, cylinder pressure, combustion duration, brake specific fuel consumption (BSFC), gas emissions ( THC, NOx, CO) and particle emission were measured before and after the injector fouling test at eight different operation conditions. The test results indicated that, although the injector flow rate and injection pulse did not change a lot after the injector fouling test which means few internal deposit was built inside the injector hole, it still had some effect on engine combustion and emissions.
2017-10-08
Technical Paper
2017-01-2246
Xuwei Luo, Ho Teng, Yuxing Lin, Bin Li, Xiaochun Zeng, Tingjun Hu, Xianlong Huang, Xiaojun Yuan
Atkinson cycle realized with a late intake valve closing (LIVC) and Miller cycle achieved with an early intake valve closing (EIVC) have been recognized as effective approaches for improving the gasoline engine fuel economy. In both Atkinson and Miller cycles, the engine can be designed with a higher geometric compression ratio for increasing the expansion work and the effective compression ratio is governed by the intake valve close (IVC) timing for the knock control. Duration of the intake event and IVC timing affect not only the pumping loss during the gas exchange, but also have strong influences on the friction torques of the intake cams and the turbulence intensities for the in-cylinder charge motion. The latter governs duration of combustion and EGR tolerance, both of which have impacts on the engine thermal efficiency.
2017-10-08
Technical Paper
2017-01-2254
Sirui Huang, Changpu Zhao, Yayong Zhu
In order to improve the combustion and emissions for high-speed marine diesel engines, numerical investigations on effects of different combustion chamber structures combined with intake air humidification have to be conducted in this paper. The study uses AVL Fire code to establish three-dimensional combustion model and simulate the in-cylinder flow, air-fuel mixing and combustion process with the flow dynamics metrics such as swirl number and uniformity index, analyze the interactional effects of combustion chamber structures and intake air humidification against the experimental data for a part load operation at 1350 r/min, find the optimized way to improve engine performance as well as decrease the NOx and soot emissions. The novelty is that this study is to combine different air humidifying rates with different combustion chamber structures including the re-entrant chamber, the straight chamber and the open chamber.
2017-10-08
Technical Paper
2017-01-2252
Weihua Sun, Wei Du, Xuefei Dai, Xiangdong Bai, Zhiping Wu
Getting real cylinder pressure is the basis of engine combustion analysis. Because of the advantages of good thermal performance, fast response, small size, high accuracy, large range and so on, piezoelectric quartz sensor is widely used in the measurement of the cylinder pressure. But this kind of sensor can only get the dynamic cylinder pressure which may not represent the real one. In this situation, the cylinder pressure needs to be corrected by some method. It also could cause great result divergences of the combustion analysis by using different cylinder pressure correction methods. This paper aims to acquire a proper cylinder pressure correction method by carrying out the theory analysis based on ideal gas equation and experiment research of cylinder pressure on a turbocharged eight-cylinder diesel engine.
2017-10-08
Technical Paper
2017-01-2259
Tianpu Dong, Fujun Zhang, Hongli Gao, Sufei Wang, Yidong Fei
The diesel low temperature combustion(LTC) can keep high efficiency and produce low emission. It has been widely studied at home and abroad in recent years. The combustion control parameters such as injection pressure, injection timing, intake oxygen concentration, intake pressure, intake temperature and so on, have an important influence on the combustion and emission of diesel LTC. In order to realize different combustion modes and combustion mode switch of diesel engine, it is necessary to accurately control the injection parameters and intake parameters of diesel engine. In this work, the effect of intake oxygen concentration, intake pressure and intake temperature on the combustion and emission characteristics of diesel LTC were analyzed by experimental study. Combustion performance and emission characteristics such as in-cylinder pressure, temperature, heat release rate, NOx and soot emission are presented and discussed.
2017-10-08
Technical Paper
2017-01-2264
Hyun Woo Won, Alexandre Bouet, Joseph Kermani, Florence Duffour, Simon Dosda
Recent work has demonstrated the potential of gasoline-like fuels to reduce NOx and particulate emissions when used in compression ignition engines. In this context, low RON gasoline, a refinery stream derived from the atmospheric crude oil distillation process, has been identified as a highly valuable fuel. In addition, thanks to its higher H/C ratio and energy content compared to diesel, CO2 benefits are also expected when used in such engines. In previous studies, different Cetane Number (CN) fuels have been evaluated and a CN 35 fuel has been selected. The assessment and the choice of the required engine hardware adapted to this fuel, such as the compression ratio, bowl pattern and nozzle design have been performed on a single cylinder compression-ignition engine. The purpose of this paper is to assess different airpath and after treatment system (ATS) definitions to maximize the potential of a low-RON gasoline fuel running on a multi-cylinder compression ignition engine.
2017-10-08
Technical Paper
2017-01-2263
S. Vedharaj, R Vallinayagam, Yanzhao An, Mohammad Izadi Najafabadi, Bart Somers, Junseok Chang, Bengt Johansson
Naphtha boils in the gasoline range of 40°C to 75°C with a RON of 65, showing increased resistance to auto-ignition. It is not possible to use naphtha as a drop in fuel for CI engine and therefore, it is ideal to investigate premixed combustion of naphtha. Previous studies reports the use of naphtha in CI engine under partially premixed combustion (PPC) mode, wherein the fuel injection timing and intake air temperature controls combustion. In this study, we investigate the combustion visualization and stratification of surrogate fuel in PPC mode. The composition of naphtha surrogate is 2-methyl butane (0.21% mol), 2-methyl hexane (0.07% mol), n-pentane (0.6% mol), n-heptane (0.07% mol) and toluene (0.05% mol). Investigation of surrogate fuel in engine expands on the previous studies on surrogate fuel formation for naphtha. Based on the experimental outcome, start of injection (SOI) was found to be inversely correlated with combustion phasing during early injection timings.
2017-10-08
Technical Paper
2017-01-2262
Changle Li, Per Tunestal, Martin Tuner, Bengt Johansson
In a former research, the sensitivity of combustion phasing to intake temperature and injection timing during the transition from HCCI to PPC were investigated, fueling with generic gasoline. While digging into the results, special interest was drawn into the relationship between the intake temperature and combustion phasing since it was believed that it properly revealed the changing of stratification level with the injection timing. To confirm its applicability on different fuels also investigate the effect of fuel properties on the formation of stratification, primary reference fuels (PRF) was tested with the same method: a start of injection sweep from -180° to -20° aTDC (after top dead center) with the combustion phasing kept constant by tuning the intake temperature. The results were compared with the former results of gasoline, and the previous conclusions were further developed. A three-stage fuel-air stratification development process, from HCCI to PPC, was observed.
2017-10-08
Technical Paper
2017-01-2265
Hao-ye Liu, Zhi Wang, Bowen Li, Shi-Jin Shuai, Jian-Xin Wang
Wide Distillation Fuel (WDF) refers to the fuels with a distillation range from initial boiling point of gasoline to final boiling point of diesel. Recent experimental results have shown WDF by blending 50% gasoline and 50% diesel (G50) exhibits much lower soot emissions than diesel at medium load with relatively low injection ratio with similar thermal efficiency. However, the engine performances fueled by G50 at both low load end and high load end are still unknown. In this study, the combustion and emission characteristics of G50 and diesel have been compared at 1600 r/min and a wide load range from 0.2 MPa IMEP to 1.4 MPa IMEP at a light-duty diesel engine. The results shown that G50 has much lower soot emissions and similar thermal efficiency compared with diesel at high load end. At 0.2 MPa IMEP, G50 exhibits high cycle-to-cycle variation and low thermal efficiency.
2017-10-08
Technical Paper
2017-01-2267
Erik Svensson, Lianhao Yin, Per Tunestal, Martin Tuner
The concept of Partially Premixed Combustion (PPC) in engines has shown to achieve very high gross indicated efficiencies, but at the expense of gas exchange efficiencies. Most of the experimental research on PPC has been conducted on compression ignition engines designed to operate on diesel fuel and relatively high exhaust temperatures. The PPC concept on the other hand relies on dilution with high exhaust gas recirculation (EGR) rates to slow down the combustion which results in low exhaust temperatures, but also high mass flows over cylinder, valves, ports and manifolds. A careful design of the gas exchange system, EGR and charge air coolers is therefore of utter importance. Experiments were performed on a heavy-duty, compression ignition engine using a fuel consisting of 80 percent 89 RON gasoline and 20 percent n-heptane. A wide range of engine speeds and loads were run using a long route EGR system.
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