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Viewing 31 to 60 of 16430
2017-03-28
Technical Paper
2017-01-0123
Saiful Bari
Abstract In general, diesel engines have an efficiency of about 35% and hence, a considerable amount of energy is expelled to the ambient air. In water-cooled engines, about 25%, 33% and 7% of the input energy are wasted in the coolant, exhaust gas, and friction, respectively. The heat from the exhaust gas of diesel engines can be an important heat source to provide additional power and improve overall engine efficiency. Studies related to the application of recoverable heat to produce additional power in medium capacity diesel engines (< 100 kW) using separate Rankine cycle are scarce. To recover heat from the exhaust of the engine, an efficient heat exchanger is necessary. For this type of application, the heat exchangers are needed to be designed in such a way that it can handle the heat load with reasonable size, weight and pressure drop. This paper describes the study of a diesel generator-set attached with an exhaust heat recovery system.
2017-03-28
Technical Paper
2017-01-0150
Ankit Kumar Shukla, Raj Dhami, Aashish Bhargava, Sanjay Tiwari
Abstract In the current landscape of commercial vehicle industry, fuel economy is one of the major parameter for fleet owner’s profitability as well as greenhouse gasses emission. Less fuel efficiency results in more fuel consumption; use of conventional fuel in engines also makes environment polluted. The rapid growth in fuel prices has led to the demand for technologies that can improve the fuel efficiency of the vehicle. Phase change material (PCMs) for Thermal energy storage system (TES) is one of the specific technologies that not only can conserve energy to a large extent but also can reduce emission as well as the dependency on convention fuel. There is a great variety of PCMs that can be used for the extensive range of temperatures, making them attractive in a number of applications in automobiles.
2017-03-28
Technical Paper
2017-01-0158
Masaaki Nakamura, Koichi Machida, Kiyohiro Shimokawa
Abstract A diesel engine is advantageous in its high thermal efficiency, however it still wastes about 50% of total input energy to exhaust and cooling losses. A feasibility study of thermoacoustic refrigerator was carried out as one of the means to recuperate waste heat. The thermoacoustic refrigerator prototyped for this study showed a capability to achieve cooling temperature lower than -20 degree C, which indicated that the system has a potential to be used in refrigerator trucks not only for cargo compartment cooling but also for cabin cooling.
2017-03-28
Technical Paper
2017-01-0155
Yongbing Xu, Gangfeng Tan, Xuexun Guo, Xianyao Ping
Abstract The closed cabin temperature is anticipated to be cooled down when it is a bit hot inside the driving car. The traditional air-condition lowers the cabin temperature by frequently switching the status of the compressor, which increases the engine’s parasitic power and shortens the compressor’s service-life. The semiconductor auxiliary cooling system with the properties of no moving parts, high control precision and quick response has the potential to assist the on-board air-condition in modulating the cabin temperature with relative small ranges. Little temperature differences between the cabin and the outside environment means that the system energy consumption to ensure the occupant comfort is relatively low and the inefficiency could be made up by the renewable energy source.
2017-03-28
Technical Paper
2017-01-0159
Peng Liu, Ge-Qun Shu, Hua Tian, Xuan Wang, Dongzhan Jing
Abstract The environmental issues combined with the rising of crude oil price have attracted more interest in waste heat recovery of marine engine. Currently, the thermal efficiency of marine diesels only reaches 48~51%, and the rest energy is rejected to the environment. Meanwhile, energy is required when generating electricity and cooling that are necessary for vessels. Hence, the cogeneration system is treated as the promising technology to conform the strict environment regulation while offering a high energy utilization ratio. In this paper, an electricity and cooling cogeneration system combined of Organic Rankine Cycle (ORC) and Absorption Refrigeration Cycle (ARC) is proposed to recover waste heat from marine engine. ORC is applied to recover exhaust waste heat to provide electricity while ARC is used to utilize condensation heat of ORC to produce additional cooling.
2017-03-28
Technical Paper
2017-01-0181
Benny Johnson William, Agathaman Selvaraj, Manjeet Singh Rammurthy, Manikandan Rajaraman, V. Srinivasa Chandra
Abstract The modern day automobile customers’ expectations are sky-high. The automotive manufacturers need to provide sophisticated, cost-effective comfort to stay in this competitive world. Air conditioning is one of the major features which provides a better comfort but also adds up to the increase in operating fuel cost of vehicle. According to the sources the efficiency of internal combustion engine is 30% and 70% of energy is wasted to atmosphere. The current Air conditioners in automobiles use Vapour compression system (VCS) which utilizes a portion of shaft power of the engine at its input; this in turn reduces the brake power output and increases the specific fuel consumption (SFC) of the engine. With the current depletion rate of fossil fuels, it is necessary to conserve the available resources and use it effectively which also contributes to maintain a good balance in greenhouse effect thus protecting the environment.
2017-03-28
Technical Paper
2017-01-0263
Krishnaraj Udayachalam, Manan Trivedi, Ziliang Zheng, Amit Shrestha, Naeim Henein
Abstract SASOL IPK is a low cetane number synthetic fuel formed from coal by the Fischer-Tropsch process which can be used as an extender to JP8, currently used in military ground vehicles. This paper presents two surrogates developed considering the following criteria: (a) availability of kinetic combustion models for each component, (b) smallest number of components to reduce computation time and cost, (c) matching the following properties of target fuel DCN, distillation curve, density, LHV, MW and H/C ratio. The autoignition and combustion characteristics of the surrogates were validated in IQT according to ASTM D6890-10a. Surrogate formulation strategy involves an equation to calculate DCN of the surrogate mixture from the DCN of each component. The linear equation commonly used for such calculations was modified to include a multiplier, based on regression analysis, for each component to produces DCN values that agree well with the measured DCN in the IQT.
2017-03-28
Technical Paper
2017-01-0190
Neelakandan Kandasamy, Steve Whelan
Abstract The range of Plug-In Electric Vehicles (EVs) is highly influenced by the electric power consumed by various sub systems, the major part of the power being used for vehicle climate control strategies in order to ensure an acceptable level of thermal comfort for the passengers. Driving range decreases with low temperatures in particular because cabin heating system requires significant amount of electric power. Range also decreases with high ambient temperatures because of the air conditioning system with electrically-driven compressor. Both thermal systems reduce EV driving range under real life operating cycles, which can be a barrier against market penetration. The structure of a vehicle is capable of absorbing a significant amount of heat when exposed to hot climate conditions. 50-70% of this heat penetrates through the glazing and raises both the internal cabin air temperature and the interior trim surface temperature.
2017-03-28
Technical Paper
2017-01-0184
Miyoko Oiwake, Ozeki Yoshiichi, Sogo Obata, Hideaki Nagano, Itsuhei Kohri
Abstract In order to develop various parts and components for hybrid electric vehicles, understanding the effect of their structure and thermal performance on their fuel consumption and cruising distance is essential. However, this essential information is generally not available to suppliers of vehicle parts and components. In this report, following a previous study of electric vehicles, a simple method is proposed as the first step to estimate the algorithm of the energy transmission and then the cruising performance for hybrid electric vehicles. The proposed method estimates the cruising performance using only the published information given to suppliers, who, in general, are not supplied with more detailed information. Further, an actual case study demonstrating application of the proposed method is also discussed.
2017-03-28
Technical Paper
2017-01-0568
Valentina Fraioli, Carlo Beatrice, Gabriele Di Blasio, Giacomo Belgiorno, Marianna Migliaccio
Abstract The adoption of gaseous fuels for Light Duty (LD) engines is considered a promising solution to efficiently reduce greenhouse gases emissions and diversify fuels supplies, while keeping pollutants production within the limits. In this respect, the Dual Fuel (DF) concept has already proven to be, generally speaking, a viable solution, industrially implemented for several applications in the Heavy-Duty (HD) engines category. Despite this, some issues still require a technological solution, preventing the commercialization of DF engines in wider automotive fields, including the release of high amounts of unburned species, possibility of engine knock, chance of thermal efficiency reduction. In this framework, numerical simulation can be a useful tool, not only to better understand specific characteristics of DF combustion, but also to explore specific geometrical modifications and engine calibrations capable to adapt current LD architectures to this concept.
2017-03-28
Technical Paper
2017-01-0012
Zia Hossain, Shengling Deng, Jim Sellers, Gary Loechelt, Mo Grimaldi, Irene Wan, Emily Linehan, Alexander Young, Ali Salih
Abstract To meet the increasing demand for lower RDS(ON) MOSFETs in medium voltage automotive applications, the shielded gate trench MOSFET architecture is becoming increasingly popular in recent years for its ability to achieve both lower RDS(ON) and faster switching speed. The lower specific drain-to-source resistance (RDS(ON).Area) translates into smaller chip size and consequently cheaper die cost for the end customers. Furthermore, shielded gate trench architecture offers smaller gate-to-drain capacitance by utilizing the shielding effect from the shield-poly, leading to lower G-D charge (QGD), faster switching speed, and increased dv/dt immunity. A comprehensive portfolio of medium voltage shielded gate power MOSFET products in several voltage classes (40V, 60V, 80V, and 100V) in automotive and industrial markets is presented in this paper.
2017-03-28
Technical Paper
2017-01-0482
Cristiano Grings Herbert, Luiz Rogério De Andrade Lima, Cristiane Gonçalves
Abstract Phthalates have been extensively used in rubbers formulation as plasticizer additive for PVC and NBR promoting processing parameters or for cost reduction. The most commonly used plasticizer in PVC compounds was di-2-ethylhexyl phthalate (DEHP) currently not recommend due toxicity. DEHP is listed as prohibited to the Global Automotive Declarable Substance List (GADSL). Phthalates alternatives are already available but the compatibility in automotive fuel system with biodiesel was not extensively understood. This aspect is important since plasticizer may migrate and change rubber properties. Tri-2-ethylhexyl trimellitate (TOTM) and di-2-ethylhexyl terephthalate (DEHT) were selected in this work as alternative additives to a rubber formulation since is not listed to GADSL and have good potential as plasticizer.
2017-03-28
Technical Paper
2017-01-0545
Adrian Irimescu, Silvana Di Iorio, Simona Silvia Merola, Paolo Sementa, Bianca Maria Vaglieco
Abstract Multi-fuel operation is one of the main topics of investigative research in the field of internal combustion engines. Spark ignition (SI) power units are relatively easily adaptable to alternative liquid-as well as gaseous-fuels, with mixture preparation being the main modification required. Numerical simulations are used on an ever wider scale in engine research in order to reduce costs associated with experimental investigations. In this sense, quasi-dimensional models provide acceptable accuracy with reduced computational efforts. Within this context, the present study puts under scrutiny the assumption of spherical flame propagation and how calibration of a two-zone combustion simulation is affected when changing fuel type. A quasi-dimensional model was calibrated based on measured in-cylinder pressure, and numerical results related to the two-zone volumes were compared to recorded flame imaging.
2017-03-28
Technical Paper
2017-01-0538
Corinna Netzer, Lars Seidel, Michal Pasternak, Christian Klauer, Cathleen Perlman, Frederic Ravet, Fabian Mauss
Abstract Engine knock is an important phenomenon that needs consideration in the development of gasoline fueled engines. In our days, this development is supported by the use of numerical simulation tools to further understand and subsequently predict in-cylinder processes. In this work, a model tool chain based on detailed chemical and physical models is proposed to predict the auto-ignition behavior of fuels with different octane ratings and to evaluate the transition from harmless auto-ignitive deflagration to knocking combustion. In our method, the auto-ignition and emissions are calculated based on a new reaction scheme for mixtures of iso-octane, n-heptane, toluene and ethanol (Ethanol consisting Toluene Reference Fuel, ETRF). The reaction scheme is validated for a wide range of mixtures and every desired mixture of the four fuel components can be applied in the engine simulation.
2017-03-28
Technical Paper
2017-01-0539
Duc-Khanh Nguyen, Sebastian Verhelst
Abstract Methanol fueled spark ignition (SI) engines have the potential for very high efficiency using an advanced heat recovery system for fuel reforming. In order to allow simulation of such an engine system, several sub-models are needed. This paper reports the development of two laminar burning velocity correlations, corresponding to two reforming concepts, one in which the reformer uses water from an extra tank to produce hydrogen rich gas (syngas) and another that employs the water vapor in the exhaust gas recirculation (EGR) stream to produce reformed-EGR (R-EGR). This work uses a one-dimensional (1D) flame simulation tool with a comprehensive chemical kinetic mechanism to predict the laminar burning velocities of methanol/syngas blends and correlate it. The syngas is a mixture of H2/CO/CO2 with a CO selectivity of 6.5% to simulate the methanol steam reforming products over a Cu-Mn/Al catalyst.
2017-03-28
Technical Paper
2017-01-0522
Jianning Zhao, Antonio Sciarretta
Abstract Fuel consumption is an essential factor that requires to be minimized in the design of a vehicle powertrain. Simple energy models can be of great help - by clarifying the role of powertrain dimensioning parameters and reducing the computation time of complex routines aiming at optimizing these parameters. In this paper, a Fully Analytical fuel Consumption Estimation (FACE) is developed based on a novel GRaphical-Analysis-Based fuel Energy Consumption Optimization (GRAB-ECO), both of which predict the fuel consumption of light- and heavy-duty series hybrid-electric powertrains that is minimized by an optimal control technique. When a drive cycle and dimensioning parameters (e.g. vehicle road load, as well as rated power, torque, volume of engine, motor/generators, and battery) are considered as inputs, FACE predicts the minimal fuel consumption in closed form, whereas GRAB-ECO minimizes fuel consumption via a graphical analysis of vehicle optimal operating modes.
2017-03-28
Technical Paper
2017-01-0855
Rakesh Kale, R. Banerjee
Abstract Use of bio fuels in a regular spark ignition engine is becoming common in several countries to reduce the dependence on fossil fuels and overall generation of green house emissions. Alcohols such as methanol and ethanol are blended with gasoline when SI engines are considered. Advanced direct injection stratified charge engine technology has gained lot of interest due to its merits over conventional port fuel injection engine. Since the technology is significantly spray controlled, fuel injection and spray behavior under different thermodynamic conditions plays a very important role in successful engine operation. Present work was carried out to understand the spray behavior of isooctane and three alcohols under engine-like pressure and temperature conditions. Selected alcohols were ethanol, isobutanol and n-butanol. A six holes solenoid injector was used for this study.
2017-03-28
Technical Paper
2017-01-0665
Hassan vafamehr, Alasdair Cairns, Mohammadmohsen Moslemin Koupaie
Abstract The experimental work was concerned with improving understanding of the competing effects of the latent heat of vaporization and auto-ignition delay times of different ethanol blended fuels during heaving knocking combustion. The unique single cylinder SI engine employed included full bore overhead optical access capable of withstanding unusually high in-cylinder pressures. Heavy knock was deliberately induced under moderate loads using inlet air heating and a primary reference fuel blend of reduced octane rating. High-speed chemiluminescence imaging and simultaneous in-cylinder pressure data measurement were used to evaluate the combustion events. Under normal operation the engine was operated under port fuel injection with a stoichiometric air-fuel mixture. Multiple centered auto-ignition events were regularly observed, with knock intensities of up to ~40bar. Additional excess fuel of varied blend was then introduced directly into the end-gas in short transient bursts.
2017-03-28
Technical Paper
2017-01-0654
Haiqiao Wei, Dengquan Feng, Mingzhang pan, JiaYing PAN
Abstract Combustion characteristics of neat 2-methylfuran (MF), 10% and 20% volumetric fraction 2-methylfuran gasoline blends were experimentally investigated in a single cylinder spark ignition engine, and the results were benchmarked against that of the research on octane number 97 neat gasoline. The investigation focused on the performance of cyclic variation of MF and its blends, and the effects of spark ignition timing, compression ratio, and exhaust gas recirculation (EGR) were studied. Experiments were conducted at the engine speed of 1500 rpm, and loads between 7 and 11 bar indicated mean effective pressure (IMEP) with using stoichiometric air-fuel ratio mixture. Index of the coefficient of variation of IMEP (COVIMEP) was used to evaluate the combustion stability of the tested fuels. The results show that neat MF and MF gasoline blended fuels have superior combustion stability compared with gasoline.
2017-03-28
Technical Paper
2017-01-0655
Mohammadmohsen Moslemin Koupaie, Alasdair Cairns, Hassan vafamehr, Thompson Lanzanova
Abstract This work was concerned with study of the in-cylinder flow field and flame development in a spark ignition research engine equipped with Bowditch piston optical access. High-speed natural light (chemiluminescence) imaging and simultaneous in-cylinder pressure data measurement and analysis were used to understand the fundamentals of flame propagation for a variety of ethanol fuels blended with either gasoline or iso-octane. PIV was undertaken on the same engine in a motoring operation at a horizontal imaging plane close to TDC (10 mm below the fire face) throughout the compression stroke (30°,40°,90° and 180°bTDC) for a low load engine operating condition at 1500rpm/0.5 bar inlet plenum pressure. Up to 1500 cycles were considered to determine the ensemble average flow-field and turbulent kinetic energy. Finally, comparisons were made between the flame and flow experiments to understand the apparent interactions.
2017-03-28
Technical Paper
2017-01-0738
Akhilendra Pratap Singh, Avinash Kumar Agarwal
Abstract Premixed charge compression ignition (PCCI) combustion is an advanced combustion technique, which has the potential to be operated by alternative fuels such as alcohols. PCCI combustion emits lower oxides of nitrogen (NOx) and particulate matter (PM) and results thermal efficiency similar to conventional compression ignition (CI) engines. Due to extremely high heat release rate (HRR), PCCI combustion cannot be used at higher engine loads, which make it difficult to be employed in production grade engines. This study focused on development of an advanced combustion engine, which can operate in both combustion modes such as CI combustion as well as PCCI combustion mode. This Hybrid combustion system was controlled by an open engine control unit (ECU), which varied the fuel injection parameters for mode switching between CI and PCCI combustion modes.
2017-03-28
Technical Paper
2017-01-0733
Mario Martins, Ivanir Fischer, Franciel Gusberti, Rafael Sari, Macklini Dalla Nora
Abstract Ethanol with high levels of hydration is a low cost fuel that offers the potential to replace fossil fuels and contribute to lower carbon dioxide (CO2) emissions. However, it presents several ignition challenges depending on the hydration level and ambient temperature. Advanced combustion concepts such as homogeneous charge compression ignition (HCCI) have shown to be very tolerant to the water content in the fuel due to their non-flame propagating nature. Moreover, HCCI tends to increase engine efficiency while reducing oxides of nitrogen (NOx) emissions. In this sense, the present research demonstrates the operation of a 3-cylinder power generator engine in which two cylinders operate on conventional diesel combustion (CDC) and provide recycled exhaust gas (EGR) for the last cylinder running on wet ethanol HCCI combustion. At low engine loads the cylinders operating on CDC provide high oxygen content EGR for the dedicated HCCI cylinder.
2017-03-28
Technical Paper
2017-01-0734
Eshan Singh, Muhammad Waqas, Bengt Johansson, Mani Sarathy
Abstract The blending of ethanol with primary reference fuel (PRF) mixtures comprising n-heptane and iso-octane is known to exhibit a non-linear octane response; however, the underlying chemistry and intermolecular interactions are poorly understood. Well-designed experiments and numerical simulations are required to understand these blending effects and the chemical kinetic phenomenon responsible for them. To this end, HCCI engine experiments were previously performed at four different conditions of intake temperature and engine speed for various PRF/ethanol mixtures. Transfer functions were developed in the HCCI engine to relate PRF mixture composition to autoignition tendency at various compression ratios. The HCCI blending octane number (BON) was determined for mixtures of 2-20 vol % ethanol with PRF70. In the present work, the experimental conditions were considered to perform zero-dimensional HCCI engine simulations with detailed chemical kinetics for ethanol/PRF blends.
2017-03-28
Technical Paper
2017-01-0727
Ida Truedsson, Christine Rousselle, Fabrice Foucher
Abstract The transportation sector adds to the greenhouse gas emissions worldwide. One way to decrease this impact from transportation is by using renewable fuels. Ethanol is a readily available blend component which can be produced from bio blend­stock, currently used blended with gasoline from low to high concentrations. This study focuses on a high octane (RON=97) gasoline blended with 0, 20, and 50, volume % of ethanol, respectively. The high ethanol blended gasoline was used in a light duty engine originally designed for diesel combustion. Due to the high octane rating and high ignition resistance of the fuel it required high intake temperatures of 443 K and higher to achieve stable combustion in in homogeneously charged compression ignition (HCCI) combustion operation at low load. To enable combustion with lower intake temperatures more commonly used in commercial vehicles, ozone was injected with the intake air as an ignition improver.
2017-03-28
Technical Paper
2017-01-0726
Muhammad Waqas, Nimal Naser, Mani Sarathy, Jeroen Feijs, Kai Morganti, Gustav Nyrenstedt, Bengt Johansson
Abstract Gasoline-ethanol-methanol (GEM) blends, with constant stoichiometric air-to-fuel ratio (iso-stoichiometric blending rule) and equivalent to binary gasoline-ethanol blends (E2, E5, E10 and E15 in % vol.), were defined to investigate the effect of methanol and combined mixtures of ethanol and methanol when blended with three FACE (Fuels for Advanced Combustion Engines) Gasolines, I, J and A corresponding to RON 70.2, 73.8 and 83.9, respectively, and their corresponding Primary Reference Fuels (PRFs). A Cooperative Fuel Research (CFR) engine was used under Spark Ignition and Homogeneous Charge Compression Ignited modes. An ignition quality tester was utilized in the Compression Ignition mode. One of the promising properties of GEM blends, which are derived using the iso-stoichiometric blending rule, is that they maintain a constant octane number, which has led to the introduction of methanol as a drop-in fuel to supplement bio-derived ethanol.
2017-03-28
Technical Paper
2017-01-0764
Gabriele Di Blasio, Giacomo Belgiorno, Carlo Beatrice
Abstract The paper reports the results of an experimental campaign aimed to assess the impact of the compression ratio (CR) variation on the performance and pollutant emissions, including the particle size spectrum, of a single cylinder research engine (SCE), representatives of the engine architectures for automotive application, operated in dual-fuel methane-diesel mode. Three pistons with different bowl volumes corresponding to CR values of 16.5, 15.5 and 14.5 were adopted for the whole test campaign. The injection strategy was based on two injection pulses per cycle, as conventionally employed for diesel engines. The test methodology per each CR included the optimization of both 1st injection pulse quantity and intake air mass flow rate in order to lower as much as possible the unburned methane emissions (MHC).
2017-03-28
Technical Paper
2017-01-0769
Pierpaolo Napolitano, Chiara Guido, Carlo Beatrice, Nicola Del Giacomo
Abstract An increasing interest in the use of natural gas in CI engines is currently taking place, due to several reasons: it is cheaper than conventional Diesel fuel, permits a significant reduction of carbon dioxide and is intrinsically clean, being much less prone to soot formation. In this respect, the Dual Fuel concept has already proven to be a viable solution, industrially implemented for several applications in the heavy duty engines category. An experimental research activity was devoted to the analysis of the potentiality offered by the application of a Dual Fuel Diesel-CNG configuration on a light duty 2L Euro 5 automotive diesel engine, equipped with an advanced control system of the combustion. The experimental campaign foresaw to test the engine in dynamic and steady state conditions, comparing engine performance and emissions in conventional Diesel and Dual Fuel combustion modes.
2017-03-28
Technical Paper
2017-01-0759
Rasmus Pettinen, Ossi Kaario, Martti Larmi
Abstract Dual-fuel technology is suggested as a solution for effectively utilizing alternative fuel types in the near future. Charge air mixed methane combined with a compression ignition engine utilizing a small diesel pilot injection seems to form a worthwhile compromise between good engine efficiency and low emission outcome. Problems concerning dual-fuel technology profitableness seems to be related to fully control the combustion in relation to lean conditions. Lean operating conditions solves the problems concerning pumping losses, but brings challenges in controlling the slow heat release of the premixed methane-air mixture. In the present work, a single cylinder ‘free parameter’ diesel engine was adapted for dual-fuel (diesel-methane) usage. A parameter study related to lambda window widening possibilities was carried out.
2017-03-28
Technical Paper
2017-01-0756
Zhenkuo Wu, Christopher Rutland, Zhiyu Han
Abstract Natural gas is a promising alternative fuel for internal combustion engines due to its rich reserves and low price, as well as good physical and chemical properties. Its low carbon structure and high octane number are beneficial for CO2 reduction and knock mitigation, respectively. Diesel and natural gas dual fuel combustion is a viable pathway to utilize natural gas in diesel engines. To achieve high efficiency and low emission combustion in a practical diesel engine over a wide range of operating conditions, understanding the performance responses to engine system parameter variations is needed. The controllability of two combustion strategies, diesel pilot ignition (DPI) and single injection reactivity controlled compression ignition (RCCI), were evaluated using the multi-dimension CFD simulation in this paper.
2017-03-28
Technical Paper
2017-01-0758
Yaopeng Li, Ming Jia, Yachao Chang, Guangfu Xu
Abstract Multi-dimensional models coupled with a reduced chemical mechanism were used to investigate the effect of fuel on exergy destruction fraction and sources in a reactivity controlled compression ignition (RCCI) engine. The exergy destruction due to chemical reaction (Deschem) makes the largest contribution to the total exergy destruction. Different from the obvious low temperature heat release (LTHR) behavior in gasoline/diesel RCCI, methanol has a negative effect on the LTHR of diesel, so the exergy destruction accumulation from LTHR to high temperature heat release (HTHR) can be avoided in methanol/diesel RCCI, contributing to the reduction of Deschem. Moreover, the combustion temperature in methanol/diesel RCCI is higher compared to gasoline/diesel RCCI, which is also beneficial to the lower exergy destruction fraction. Therefore, the exergy destruction of methanol/diesel RCCI is lower than that of gasoline/diesel RCCI at the same combustion phasing.
Viewing 31 to 60 of 16430