Browse Topic: Exhaust gas recirculation (EGR)

Items (2,716)
On-Board Diagnostic (OBD) strategies utilize a predictive model to estimate engine out NOx levels for a given set of operating conditions to ensure the accuracy of the Nitrogen Oxides (NOx) sensor. Furthermore, this model is also used to determine urea dosing quantities in situations where the NOx sensor is unavailable such as cold starts or as a reaction to a NOx sensor plausibility failure. Physics-based NOx prediction models guarantee high levels of accuracy in real-time but are computationally expensive and require measurements generally not available on commercial powertrains making them difficult to implement on controllers. Consequently, manufacturers tend to adopt a mathematical approach by estimating NOx under standard operating conditions and use a variety of correction factors to account for any changes that can influence NOx production. Such correction factors tend to be outcomes of base engine calibration settings or outputs of models of other related sub systems and may
Sunder, AbinavSuresh, RahulPolisetty, Srinivas
The internal combustion engine (ICE) is projected to remain the dominant technology in the transport sector over the short to medium term, and there exists significant potential for further improvements in fuel economy and emission reductions. One promising approach to enhancing the efficiency of spark ignition engines is the implementation of passive pre-chamber spark plugs. The primary advantages of pre-chamber-initiated combustion include the mitigation of knocking, an increase in in-cylinder turbulence, and a combustion process that is both faster and more stable compared to that achieved with conventional J-gap spark plugs. Additionally, the higher ignition energy provided by pre-chamber spark plugs enables operation under higher intake pressures, maintains similar exhaust gas recirculation rates, and supports leaner combustion conditions. These benefits are predominantly attributed to volumetric ignition via hot, reactive jets. However, the pre-chamber spark plug also presents
Korkmaz, MetinJuressen, Sven EricRößmann, DominikKapus, Paul E.Pino, Sandro
The increasing importance of hydrogen as alternative energy source to reduce CO2 emissions in the transport sector makes its adoption in spark-ignited engines an attractive and cost-efficient alternative to fuel cell-powered vehicles. Lean combustion is the preferred operating strategy for H2-engines in order to achieve performance targets, enhance efficiency and at the same time avoid critical knocking and pre-ignition phenomena. Additionally, an effective approach to lower cylinder temperatures, relevant engine-out NOx emissions and boost pressure requirements at the same time, is an external exhaust gas recirculation (EGR) system. The aim of this work is to analyze and compare the effects of exhaust gas recirculation on the combustion of a lean hydrogen mixture in a turbocharged 4-cylinder H2-ICE with direct injection. For this investigation a load point at 18 bar BMEP and 4000 rpm is selected with and without the utilization of additional external EGR. In this case, a BTE of 38
Schmelcher, RobinKulzer, Andre CasalGal, ThomasVacca, AntoninoChiodi, MarcoGrabner, PeterGschiel, Kevin
Premixed Charge Compression Ignition (PCCI) presents a promising alternative to conventional diesel combustion (CDC), offering significant reductions in pollutant emissions by lowering local in-cylinder temperatures and enhancing fuel-air mixing. However, a significant challenge in implementing PCCI is controlling the start of combustion, especially given its narrow operating load range. This is primarily due to early ignition and knocking combustion at higher loads when using high-reactivity diesel fuel, which limits the practical applicability of PCCI mode in diesel engines. In the present study, experimental investigations are carried out on a light-duty diesel engine operating in PCCI mode using two fuel blends: 10% (D90G10) and 20% (D80G20) gasoline mixed with diesel on a volume basis. To facilitate combustion control and emission reduction, exhaust gas recirculation (EGR) and water vapor are used as charge diluents. A common rail direct injection (CRDi) system replaces the
Ranjan, Ashish PratapKrishnasamy, Anand
The dual-fuel combustion process, which is offered as a retrofit solution for conventional diesel engines by various manufacturers, represents an option for reducing emissions from internal combustion engines and is already available today. Current dual-fuel engines run on liquefied natural gas (LNG), which is usually of fossil origin. Due to the existing infrastructure and the possibility of producing LNG by means of electrolysis and methanation, LNG can already be produced in a 100% climate-neutral way and thus make a contribution to climate neutrality in the shipping industry. The adoption of exhaust gas recirculation (EGR) systems in the maritime sector became more significant in 2020 following the enforcement of the sulphur emission cap. By lowering the sulphur content in the fuel, technologies in the exhaust tract are also conceivable without the use of expensive scrubber systems. Dual-fuel LNG/diesel engines are typically operated in lean-burn mode to reduce the risk of knocking
Seipel, PascalGlauner, ManuelDinwoodie, JulesBuchholz, Bert
Decarbonizing the transport sector requires solutions that reduce CO₂ emissions while improving the efficiency of existing engine platforms. This study explores a retrofit strategy in which a heavy-duty diesel engine is converted to Otto-cycle operation and equipped with a passive pre-chamber combustion (PPCC) system. Methanol was used as the fuel due to its high octane number, low carbon intensity, and favourable combustion properties. The performance of the PPCC system is experimentally compared to conventional spark ignition (SI) across varying engine speeds, loads, and exhaust gas recirculation (EGR) levels. A dual-dilution strategy, combining lean operation (λ = 1.6) with EGR, was applied to extend dilution tolerance and assess the feasibility of operating near stoichiometry. All tests were conducted under steady-state conditions with fixed spark timing. Results show that PPCC consistently delivers faster combustion than SI across all conditions, with greater stability and reduced
Fong Cisneros, Eric J.Hlaing, PonnyaCenker, EmreAlRamadan, AbdullahTurner, James WG
It is becoming increasingly clear that research into alternative fuels, including drop-in fuels, is essential for the continued survival of the internal combustion engine. In this study, the authors have evaluated olefinic and oxygenated fuels as drop-in fuels using a single-cylinder engine and considering fuel characteristic parameters. The authors have assessed thermal efficiency by adding EGR or excess air from zero to the maximum value that allows stable combustion. Next, we attempted to predict fuel efficiency for four types of passenger cars (Japanese small K-car N/A, K-car T/C, Series HV, and Power-split HV) by changing the fuels. We created a model to estimate fuel efficiency during WLTC driving. The results indicated that fuel economy could potentially be improved by adding an olefin fuel that burns stably even with a large amount of EGR or air and an oxygen fuel whose octane number increases. It was observed that the fuel economy improvement rate was particularly notable for
Moriyoshi, YasuoXu, FuguoWang, ZhiyuanTanaka, KotaroKuboyama, Tatsuya
The document provides clarity related to multiple temperature coolant circuits used with on-highway and off-highway, gasoline, and light-duty to heavy-duty diesel engine cooling systems, or hybrid vehicle systems. These multiple temperature systems include engine jacket coolant plus at least one lower temperature system. Out of scope are the low temperature systems used in electric vehicles. This subject is covered in SAE J3073. Note that some content in SAE J3073 is likely to be of interest for hybrid vehicles. Out of scope are the terms and definitions of thermal flow control valves used in either low-temperature or high-temperature coolant circuits. This subject is covered in SAE J3142.
Cooling Systems Standards Committee
Exhaust gas recirculation (EGR) is widely used in spark ignition engines to reduce throttling losses, decrease exhaust gas temperatures, increase efficiency, and suppress knock. However, the effectiveness of EGR as a knock suppressor is dependent on the fuel type and operating condition. In this study, the effectiveness of EGR to suppress knock was tested with E10, E30, E50, E75, and E100 at a moderately boosted condition. It was found that EGR was effective at suppressing knock with E10, but high EGR rates were required to achieve a knock suppression effect with E30 and E50. No knock suppression effect was observed with E75 and E100 across all tested EGR rates. With E30 and E50, EGR that was passed through a three-way catalyst was more effective at suppressing knock at all EGR rates. Chemkin modeling with neat ethanol revealed that nitric oxide enhanced ignition by increasing the hydroxyl radical concentration in the end gas, resulting in earlier auto-ignition. Directly seeding nitric
Gandolfo, JohnGainey, BrianLawler, Benjamin
The use of hydrogen in port fuel injection (PFI) engines faces challenges related to abnormal combustions that must be addressed, especially in transient operation. The in-cylinder air-to-fuel ratio and the amount of trapped exhaust gas have a significant impact on the probability of abnormal combustion as well as NOx emissions, and should be real-time monitored in hydrogen engines. Thus, the real-time estimation of the composition and thermodynamic state of the trapped gas mixture is crucial during transient operations, although highly challenging. This study proposes an on-line real-time physics-based MIMO (Multi-Input-Multi-Output) model to accurately estimate the amount of trapped air and exhaust gas in the cylinder at the intake valve closing (IVC) event, based on the instantaneous in-cylinder pressure measurement. With proper estimation accuracy, the injector can be controlled to correctly provide the amount of fuel necessary to achieve the target air-to-fuel ratio (AFR) and
Galli, ClaudioCiampolini, MarcoDrovandi, LorenzoRomani, LucaBalduzzi, FrancescoFerrara, GiovanniVichi, GiovanniMinamino, Ryota
A reemergence of manufacturer interest in range-extended electric vehicles is being driven by increasing diversification of consumer interest in low carbon-intensity technologies in the passenger vehicle and other markets. A major advantage of range-extended electric vehicles is that they curtail consumer vehicle range anxiety while maintaining a lower vehicle cost when compared with battery electric vehicles (BEV). By incorporating a small liquid-fueled internal combustion engine (ICE), the range and “refueling” time of electrified vehicles can be significantly improved while overcoming issues with cost and weight faced by long-range battery packs. Compared to ICEs designed for non-hybrid and mild hybrid vehicles, the ICE in a range-extended electric vehicle has a unique set of requirements focused on compact size, low cost, and efficient operation within a limited engine map. A Range Extender (REx) 0.9L 2-cylinder engine was selected which prioritizes these attributes in a
Peters, NathanMarion, JoshuaPothuraju Subramanyam, SaiHoth, AlexanderBunce, Mike
Nowadays, hydrogen (H2) is rising as a key solution to fuel internal combustion engines (ICE) since it allows carbon free combustion process. At the same time, ICE fueled with H2 can reach similar performance and driving experience of gasoline fueled ones. In stoichiometric conditions, hydrogen shows higher flame speed, lower ignition energy and lower quenching distance than gasoline. Mainly for these reasons, H2 combustion is characterized by a high risk of abnormal combustion (i.e. knock and pre-ignition), relevant NOx emissions and high heat losses. On the other hand, the wide flammability range and high combustion stability of H2 allow the use of different techniques to reduce combustion reactivity. This work presents a combined approach, experimental and numerical, to assess the benefits of three mixture dilution methods. The experimental campaign, in different operating conditions, was carried out on a production derived high specific power gasoline Single Cylinder Engine (SCE
Tonelli, RobertoMedda, MassimoGullino, FabrizioSilvestri, NicolaZaffino, FrancescoMariconti, RobertoRossi, Vincenzo
Pre-chamber combustion is an advanced ignition strategy that has been shown to enhance spark ignition (SI) combustion stability in natural gas (NG) engines by providing distributed ignition sites from turbulent jets and enhancing main-chamber turbulence. Pre-chamber combustion has been proven especially advantageous compared to SI in ultra-lean and dilute operating conditions. This work involves experimental investigation of the effects of varying passive pre-chamber nozzle configuration on pre-chamber and main chamber combustion under simulated exhaust gas recirculation (EGR) dilution (0 and 20%) conditions in a heavy-duty, single-cylinder, optically accessible NG engine at stoichiometric fuel-air ratio. Pre-chamber nozzle configurations include four pre-chambers with constant nozzle area to pre-chamber volume ratio (A/V) with different nozzle sizes and orientations and one configuration with larger nozzles. The optical engine is operated in a skip-fire sequence consisting of 18
Dhotre, AkashNyrenstedt, GustavRajasegar, RajavasanthVarma, ArunSingh, SatbirNorthrop, WilliamSrna, Ales
In hydrogen-fueled internal combustion engine (H2ICE), there are some ways to reduce nitrogen oxides (NOx) emissions. Using the wide flammability range of hydrogen, such as conducting lean combustion to reduce nitrogen oxides and employing exhaust gas recirculation (EGR), have been adopted. However, challenges exist in terms of load expansion, and due to the absence of high heat capacity of carbon dioxides in the exhaust, EGR also struggles to exhibit significant effects. In such a scenario, there is growing interest in injecting water into the H2ICE as an alternative to augment the EGR effect. In this study, the spark ignition (SI) single-cylinder engine equipped with two direct injectors was used to evaluate the hydrogen and the water dual direct injection combustion system. This system involved the direct injection of hydrogen using a wall-guided gasoline direct injector and the direct injection of water into the combustion chamber using a diesel injector. This approach utilizes the
Kim, KiyeonLee, SeungilKim, SeungjaeLee, SeunghyunMin, KyoungdougOh, SechulSon, JongyoonLee, Jeongwoo
Transient operation of a diesel-fueled compression ignition engine will produce significant levels of engine-out criteria pollutants such as NOx and soot emissions due to turbocharger lag. Conventional pollutant mitigation strategies during tip-ins (large increases in load) are constrained by the soot–NOx trade-off—strategies that mitigate soot/NOx emissions often result in an increase in NOx/soot emissions. Hybridization offers the ability to use an e-machine as an energy buffer during a tip-in, allowing the engine to tip-in slower to give the turbocharger time to spin up and provide the necessary amount of air for clean, high-load operation. In this work, an in-line six-cylinder 12.8 L Detroit Diesel DD13 engine was used to study the impact of slowing the torque ramp rate of a tip-in on the effectiveness of transient emission reduction strategies for turbocharged diesel engines, including exhaust gas recirculation (EGR) valve closing, start of injection retard, and the air–fuel ratio
Gainey, BrianDatar, AdityaBhatt, AnkurLawler, Benjamin
This experimental study presents preliminary investigations of prechamber-enabled mixing-controlled combustion (PC-MCC) at −2 bar brake mean effective pressure (BMEP) and 2200 rpm with fuel-grade ethanol (E98). Experimental results are conducted on a prechamber retrofitted single-cylinder Caterpillar C9.3B test engine. First, a series of prechamber-only experiments were conducted with a motored engine to evaluate the salient combustion trends in response to relevant prechamber operating parameters. Under firing conditions, the prechamber operating strategy was assessed with respect to the impact on ignition assistance of direct-injected E98 and overall engine performance. The preliminary results indicate the jet-induced ignition process is robust and prompts diffusion combustion of E98 at diesel-like boundary conditions. The effect of external exhaust gas recirculation (EGR) on the residual tolerance of the prechamber combustion process was also investigated and showed stable
Zeman, JaredDempsey, Adam
Active fuel injection into a pre-chamber (PC) promotes high-temperature and highly turbulent jets, which ignite the cylinder gas with a very high exhaust gas recirculation (EGR) ratio, reducing emissions such as NOx. In the present study, two active PC injection strategies were designed to investigate the effect of injected hydrogen mass and PC mixture air-to-fuel equivalence ratio λ on PC combustion, jet formation, and main chamber (MC) combustion. Stoichiometric or rich hydrogen/oxygen mixtures are actively injected into the PC to enhance the combustion processes in the PC and the MC. A three-dimensional numerical engine model is developed using the commercial CFD code CONVERGE. The engine geometry and parameters adopt a modified GM 4-cylinder 2.0 L GDI gasoline engine. The local developments of gas temperature and velocity are resolved with the adaptive mesh refinement (AMR). The turbulence of the flow is computed with the k-epsilon model of the Reynolds-averaged Navier–Stokes (RANS
Yu, TianxiaoLee, Dong EunAlam, AfaqueGore, Jay P.Qiao, Li
With the continuous upgrading of emission regulations for internal combustion engines, the nitrogen oxide treatment capacity of selective catalytic reduction (SCR) aftertreatment needs to be continuously improved. In this study, based on a prototype of SCR aftertreatment, the impact of the arrangement of key components in the SCR system (urea injector, mixer, and catalyst unit) on ammonia uniformity was investigated. First, parameterized designs of the urea injector, mixer, and SCR unit were conducted. Then, using computational fluid dynamics (CFD), numerical simulations of the established aftertreatment system models with different parameter factors were performed under a high-exhaust temperature and a low-exhaust temperature conditions to study the impact of each individual parameter on ammonia uniformity. Finally, an optimized solution was designed based on the observed patterns, and the optimized samples were tested on an engine performance and emission test bench to compare their
Jie, WangJin, JianjiaoWu, Yifan
The current study investigates the influence of exhaust gas recirculation technique on the hydrogen (10lpm) inducted diesel engine using Cassia fistula derived biodiesel fuel. The focus is on evaluating the emission characteristics of the engine, with a particular emphasis on reducing NOx emissions. The study also examines the impact of varying the Exhaust Gas Recirculation (EGR) flow rate 10 and 20% on the aforementioned parameters. The novelty of this investigation lies in the comprehensive evaluation of emission metrics, particularly when combining Cassia fistula biodiesel with hydrogen induction. The experiment carried in Kirloskar TV1-V4A engine with blends consists 10%, 20%, 30% and 40% by volume of CFME blends with diesel. The inducted hydrogen at 10 lpm caused increased NOx which were discussed to suppress by EGR applications. Among the tested fuels, a blend containing 40% cassia fistula methyl ester (CFME) and 60% diesel (CFME40D60) showed the lowest hydrocarbon (HC) emissions
Veeraraghavan, SakthimuruganMadhu, S.De poures, Melvin VictorPalani, Kumaran
As regulations become more stringent, engine manufacturers are adopting innovative technologies to reduce emissions while maintaining durability and reliability. One approach involves optimizing air handling systems. Eaton developed a 48 V electric exhaust gas recirculation pump (EGRP) to reduce NOx and CO2 emissions while improving fuel efficiency when paired with a high-efficiency turbocharger. This study integrates an electric EGRP and a high-efficiency turbocharger onto a 13.6L John Deere off-road diesel engine to evaluate the impact on fuel efficiency and NOx emissions across various drive cycles including the nonroad transient cycle (NRTC), the low load application cycle (LLAC), the constant speed–load acceptance (CSLA) test, and the ramped modal cycle (RMC). The study highlights the benefits and limitations of the prototype EGRP on an off-road engine. Since the setup did not include aftertreatment systems, engine-out emissions were analyzed. Experiments were conducted at
Willoughby, AudreyAdekanbi, MichaelKakani, RaghavAhmad, Zar NigarShaver, GregHolloway, EricHaaland, EricEvers, MatthewLoesch, AdamMcClurg, JosiahBagal, NileshMcCarthy, JamesCoates, Michael
Diesel engines produce more smoke and nitrogen oxide (NOx) emissions. Hence, one has to develop a new technique that reduces these emissions besides works satisfactorily with alternative fuels in place of diesel. In this work, used temple oil biodiesel (BTO) is a candidate to replace diesel to run diesel engine. Also, common rail direction injection (CRDi) is a technique that injects fuel at a higher pressure than conventional injectors of diesel engines that produce fine fuel droplets suitable for highly viscous biodiesel. This work also uses the design of experiments (DOE) and response surface methodology (RSM) modeling approach to evaluate the performance of CRDi engine with three operating parameters namely injection timing (IT), injection pressure (IP), and exhaust gas recirculation (EGR). From the study, it could be concluded that CRDi engine showed better performance at IT of 9°bTDC, IP of 855 bar with EGR of 20% but with little reduction in thermal efficiency. The study has
Shaikh, Sardar MansoorKhandal, Sanjeevkumar V.
Our research group developed Gasoline Compression Ignition (GCI) fuel matrix based on the fuel properties, specifications and fuel sources in an effort to standardize the GCI fuel. This study attempts to experimentally validate the standardized GCI fuels to comply with the operational regimes of GCI engine. Two of the formulated GCI fuels (GCI7 and GCI8) with varying physical and chemical properties, and composition were investigated in a single cylinder compression ignition (CI) engine. In addition to fuel effects, the engine variables were parametrically varied at low (3 bar IMEP) and medium (7 bar IMEP) load conditions. At low loads, the fuel chemical effects played a crucial role in governing the combustion while physical effect had a negligible impact. Due to lower cetane number of GCI8 fuel, combustion is predominantly premixed for GCI8 fuel but GCI7 fuel shows a more pronounced diffusion combustion phase. The low temperature heat release (LTHR) is evident only for GCI8 fuel due
Qahtani, Yasser AlRaman, VallinayagamViollet, YoannAlhajhouje, AbdullahCenker, EmreAlRamadan, Abdullah
Diesel engines are largely used as power units with high fuel efficiency. Conversely, they have an adverse impact on the environment and human health as they emit high NOx and particulate matter emissions. As more stringent regulations for emissions are introduced, low temperature combustion strategy such as Gasoline Compression Ignition evolved and demonstrated the potential to reduce the particulate matter and NOx emissions by operating engines under a Partially Premixed Combustion mode. Therefore, a 0.55 mm single cylinder engine (Gasoline Direct Injection), was tested over range of engine loads with constant speed (1500 rpm) using RON80 without oxygenates. Different operating parameters such as injection, exhaust gas recirculation (EGR) etc. were used to control combustion phasing and mixture stratifications. At low loads, rebreathing of hot exhaust gas produced low levels of NOx and smoke emissions. It reduced NOx by 60% and smoke levels below 0.20 FSN when it is coupled with low
Qahtani, Yasser AlSellnau, MarkYu, Xin
This study emphasizes the importance of computer-aided engineering (CAE) approach in optimizing exhaust gas recirculation (EGR) tube under thermal load. With exhaust gases generating high temperatures, the EGR tube experiences increased stress and strain, posing challenges to its structural integrity. Moreover, the cyclic heating and cooling cycles of the engine imposes thermal fatigue, further compromising the tube’s performance over time. To address these concerns, the paper introduces a comprehensive CAE methodology for conducting factor of safety analysis. The nonlinear thermal analysis is performed on the assembly as due to high temperatures the stresses cross the yield limit. The strain-based approach is used to calculate the factor of safety. Moreover, a comprehensive case study is presented, illustrating how design modifications can enhance the thermal fatigue factor of safety. By adjusting parameters such as thickness and routing, engineers can mitigate thermal stresses and
Munde, GaneshChattaraj, SandipHatkar, ChandanGodse, Rushikesh
Dual-fuel (DF) engines enable efficient utilization of a low reactivity fuel (LRF), usually port-injected, and a high reactivity fuel (HRF) provided directly into the cylinder. Ethanol and Camelina sativa oil can be ecologically effective but not fully recognized alternatives for energy production using modern CI engines equipped with a common rail system and adopted for dual fueling. The high efficiency of the process depends on the organization of the combustion. The article describes the premixed dual-fuel combustion (PDFC) realized by dividing the Camelina sativa dose and adjusting its injection timing to the energetic share of ethanol in the DF mixture. The injection strategy of HRF is crucial to confine knock, which limits DF engine operation, but the influence of EGR is also important. The research AVL engine’s dual-fueling tests focused on combustion process modification by the proposed injection strategy and cooled EGR at different substitution rates. For all examined points
Pawlak, GrzegorzSkrzek, TomaszKosiuczenko, KrzysztofPłochocki, PatrykSimiński, Przemysław
This study emphasizes the importance of CAE approach in optimizing EGR tube under vibrational load. EGR tube is a weak link in the EGR system and chances of failure due to vibration and relative displacement of mating parts, i.e., overhang or improper support at exhaust manifold, intake manifold, or EGR system. Consideration of the mating parts for the EGR tube is very important to get the realistic resonance frequencies, otherwise it could have some different results in the CAE, which will deviate from the reality. So, it’s important to study the dynamic response on the EGR tube, which needs to be taken care during the design phase. This paper aims to optimize the EGR tube under vibrational load by using CAE techniques and the industry experience as a product expertise. some critical parameter such as damping is very important during the CAE, which can be generated by doing the rigorous testing and how it affects the stress and correspondingly FOS. CAE model of EGR tube is created on
Munde, GaneshChattaraj, SandipHatkar, ChandanThakur, Abhishek Kumar
By building on mature internal combustion engine (ICE) hardware combined with dedicated hydrogen (H2) technology, the H2-ICE has excellent potential to accelerate CO2 reduction. H2-ICE concepts can therefore contribute to realizing the climate targets in an acceptable timeframe. In the landscape of H2-ICE concepts, pilot-ignited High Pressure Direct Injection (HPDI™) is an attractive option considering its high thermal efficiency, wide load range and its applicability to on-road as well as off-road heavy-duty equipment. Still, H2-HPDI is characterized by diffusion combustion, giving rise to significant NOx emissions. In this paper, the potential of H2-HPDI toward compliance with future emissions legislation is explored on a 1.8L single-cylinder research engine. With tests on multiple load-speed points, Exhaust Gas Recirculation (EGR) was shown to be an effective measure for reducing engine-out NOx, although at the cost of a few efficiency points. Furthermore, the use of EGR was
Willems, RobbertSeykens, XanderBekdemir, CemilDoosje, ErikVan Gompel, Peter
Ammonia has emerged as a promising carbon-free alternative fuel for internal combustion engines (ICE), particularly in large-bore engine applications. However, integrating ammonia into conventional engines presents challenges, prompting the exploration of innovative combustion strategies like dual-fuel combustion. Nitrous oxide (N2O) emissions have emerged as a significant obstacle to the widespread adoption of ammonia in ICE. Various studies suggest that combining exhaust gas recirculation (EGR) with adjustments in inlet temperature and diesel injection timing can effectively mitigate nitrogen oxides (NOx) emissions across diverse operating conditions in dual-fuel diesel engines. This study conducts a numerical investigation into the impact of varying inlet charge temperatures (330K, 360K, and 390K) and EGR rates (0%, 10%, and 20%) on the combustion and emission characteristics of an ammonia/diesel dual-fuel engine operating under high-load conditions, while considering different
Hoseinpour, MarziyehKarami, RahimSalahi, Mohammad MahdiMahmoudzadeh Andwari, AminGharehghani, AyatGarcia, Antonio
In this article, the effects of mixture dilution using EGR or excessive air on adiabatic flame temperature, laminar flame speed, and minimum ignition energy are studied to illustrate the fundamental benefits of lean combustion. An ignition system developing a new active pre-chamber (APC) design was assessed, aimed at improving the indicated thermal efficiency (ITE) of a 1.5 L four-cylinder gasoline direct injection (GDI) engine. The engine combustion process was simulated with the SAGE detailed chemistry model within the CONVERGE CFD tool, assuming the primary reference fuel (PRF) to be a volumetric mixture of 93% iso-octane and 7% n-heptane. The effects of design parameters, such as APC volume, nozzle diameter, and nozzle orientations, on ITE were studied. It was found that the ignition jet velocity from the pre-chamber to the main chamber had a significant impact on the boundary heat losses and combustion phasing. The simulation showed that, under 16.46 compression ratio (CR) and
Peethambaram, Mohan RajZhou, QuanbaoWaters, BenjaminPendlebury, KenFu, HuiyuHaines, AndrewHale, DavidHu, TiegangZhang, JiaxiangWu, XuesongZhang, Xiaoyu
This work represents an advanced engineering research project partially funded by the U.S. Department of Energy (DOE). Ford Motor Company, FEV North America, and Oak Ridge National Laboratory collaborated to develop a next generation boosted spark ignited engine concept. The project goals, specified by the DOE, were 23% improved fuel economy and 15% reduced weight relative to a 2015 or newer light-duty vehicle. The fuel economy goal was achieved by designing an engine incorporating high geometric compression ratio, high dilution tolerance, low pumping work, and low friction. The increased tendency for knock with high compression ratio was addressed using early intake valve closing (EIVC), cooled exhaust gas recirculation (EGR), an active pre-chamber ignition system, and careful management of the fresh charge temperature. Engine weight reduction measures were implemented throughout the engine system making use of composite materials, advanced manufacturing techniques, and architectural
Shelby, Michael H.Case, Mark E.Chesney, Lynn A.
This paper is part of a broader research project aiming at studying, designing, and prototyping a hydrogen-powered internal combustion engine to achieve fast market implementation, reduced greenhouse gas emissions, and sustainable costs. The ability to provide a fast market implementation is linked to the fact that the technological solution would exploit the existing production chain of internal combustion engines. Regarding the technological point of view, the hydrogen engine will be a monofuel engine re-designed based on a diesel-powered engine. The redesign involves specific modifications to critical subsystems, including combustion systems, injection, ignition, exhaust gas recirculation, and exhaust gas aftertreatment. Notably, adaptations include the customization of the cylinder head for controlled ignition, optimization of camshaft profiles, and evaluation of the intake system. The implementation incorporates additive manufacturing for the production of new intake manifolds and
Malagrinò, GianfrancoAccardo, AntonellaCostantino, TrentalessandroPensato, MicheleSpessa, Ezio
Hydrogen-fuelled internal combustion engines (ICEs) offer a zero-carbon fuel option for many applications. As part of the global effort to study hydrogen ICEs Ricardo has developed single-cylinder and multi-cylinder heavy-duty engines. The engines are representative of a 13 litre Euro VI heavy-duty production application converted to run on hydrogen fuel with limited changes. The engine is fitted with direct hydrogen injectors which enable flexible injection strategies and reduce hydrogen in the intake system. Steady-state testing was carried out over an array of speed and load points covering a typical heavy-duty drive-cycle area. Engine test results are presented and analysed in this paper. The combustion system can run to values exceeding lambda 5 and 40% exhaust gas recirculation (EGR) can be tolerated. The impact of lambda, EGR, injection and ignition timing variations are presented and demonstrate how the system responds to the corresponding changes in specific heat capacity
Osborne, RichardHughes, JohnLoiudice, AngelaPenning, RichardValenta, Lukáš
In the pursuit of carbon emission reduction, hybridization has emerged as a significant trend in powertrain electrification. As a crucial aspect of hybrid powertrain system development, achieving high brake thermal efficiency (BTE) and a wide operating range with high efficiency are essential for hybrid engines to effectively integrate with the hybrid system. When developing dedicated hybrid engines (DHE), several design considerations come into play. First, in order to make efficient use of available resources and enable engine production on the same assembly line as conventional engines, it is crucial to maintain consistency in key design parameters of the cylinder head and block, thus extending the platform-based design approach. Among the key measures to achieve high BTE, cooled exhaust gas recirculation (EGR) has been extensively explored and proven effective in improving efficiency by mitigating knocking and reducing engine cooling heat loss. Fast combustion, acting as a
Xu, ZhengQiu, JieZhang, ZiQingCheng, ChuanhuiZhang, YaJunYang, YangWang, YingzhenLu, YuanZhou, ZhouLi, XiaoYang
In order to improve the fuel economy for future high-efficiency spark ignition engines, the applications of advanced combustion strategies are considered to be beneficial with an overall lean and/or exhaust gas recirculation diluted cylinder charge. Stronger and more reliable ignition sources become more favorable under extreme lean/EGR conditions. Existing research indicates that the frequency of plasma restrikes increases with increased flow velocity and decreased discharge current level, and a higher discharge current can reduce the gap resistance and maintain the stretched plasma for a longer duration under flow conditions. An in-house developed current boost control system provides flexible control of the discharge current level and discharge duration. The current boost ignition system is based on a multi-coil system with a discharge current level of 180mA. In this study, a comparative study has been conducted to investigate the efficacy of multi-coil and multi-core ignition
Yu, XiaoLeblanc, SimonWang, LinyanZheng, MingTjong, Jimi
Dual-fuel engines powered by renewable fuels provide a potential solution for reducing the carbon footprint and emissions of transportation, contributing to the goal of achieving sustainable mobility. The investigation presented in the following uses a dual-fuel engine concept running on biogas (referred to as CNG in this paper) and the e-fuel polyoxymethylene dimethyl ether (OME). The current study focuses on the effects of exhaust gas rebreathing and external exhaust gas recirculation (EGR) on emissions and brake thermal efficiency (BTE). A four-cylinder heavy-duty engine converted to dual-fuel operation was used to conduct the engine tests at a load point of 1600 min-1 and 9.8 bar brake mean effective pressure (BMEP). The respective shares of high reactivity fuel (HRF, here: OME) and low reactivity fuel (LRF, here: CNG) were varied, as were the external and internal EGR rates and their combinations. CNG was injected into the intake manifold to create a homogeneous air-fuel mixture
Jost, Ann-KathrinGuenthner, MichaelWeigel, Alexander
The widely accepted best practice for spark-ignition combustion is the four-valve pent-roof chamber using a central sparkplug and incorporating tumble flow during the intake event. The bulk tumble flow readily breaks up during the compression stroke to fine-scale turbulent kinetic energy desired for rapid, robust combustion. The natural gas engines used in medium- and heavy-truck applications would benefit from a similar, high-tumble pent-roof combustion chamber. However, these engines are invariably derived from their higher-volume diesel counterparts, and the production volumes are insufficient to justify the amount of modification required to incorporate a pent-roof system. The objective of this multi-dimensional computational study was to develop a combustion chamber addressing the objectives of a pent-roof chamber while maintaining the flat firedeck and vertical valve orientation of the diesel engine. A new combustion chamber was designed based on a commercial 11-liter natural gas
Hoag, KevinWray, ChristopherCallahan, Timothy J.Lu, QilongGilbert, IanAbidin, Zainal
Exhaust gas recirculation (EGR) is a proven strategy for the reduction of NOX emissions in spark ignited (SI) engines and compression ignition engines, especially in lean burn conditions where the increase of thermal efficiency is obtained. The dilution level of the mixture with EGR is in a conventional SI engine limited by the increase of combustion instability (CoV IMEP). A possible method to extend the EGR dilution level and ensure stable combustion is the implementation of an active pre-chamber combustion system. The pre-chamber spark ignited (PCSI) engine enables fast and stable combustion of lean mixtures in the main chamber by utilizing high ignition energy of multiple flame jets penetrating from the pre-chamber to the main chamber. In this paper, as an initial research step, a numerical analysis is performed by employing the 0D/1D simulation model, validated with the initial experimental and 3D-CFD results. The simulation model is used for the prediction of possible benefits of
Dilber, ViktorKrajnovic, JosipUgrinić, SaraSjeric, MomirTomic, RudolfKozarac, Darko
Exhaust gas recirculation technology is one of the main methods to reduce engine emissions. The pressure of the intake pipe of turbocharged direct-injection diesel engine is high, and it is difficult to realize EGR technology. The application of Venturi tube can easily solve this problem. In this paper, the working principle of guide-injection Venturi tube is introduced, the EGR system and structure of a turbocharged diesel engine using the guide-injection Venturi tube are studied. According to the working principle of EGR system of turbocharged diesel engine, the model of guide-injection Venturi tube is established, the calculation grid is divided, and it is carried out by using Computational Fluid Dynamics method that the three-dimensional numerical simulation of the internal flow of Venturi tube under different EGR rates injection. The flow field state, velocity field, pressure field and exhaust gas concentration parameters of the mixture formed by air and EGR exhaust gas in Venturi
Yang, ShuaiYan, KaiLiu, HaifengLiu, HairanLi, Tong
A numerical investigation of a six-stroke direct injection compression ignition engine operation in a low temperature combustion (LTC) regime is presented. The fuel employed is a gasoline-like oxygenated fuel consisting of 90% isobutanol and 10% diethyl ether (DEE) by volume to match the reactivity of conventional gasoline with octane number 87. The computational simulations of the in-cylinder processes were performed using a high-fidelity multidimensional in-house 3D CFD code (MTU-MRNT) with improved spray-sub models and CHEMKIN library. The combustion chemistry was described using a two-component (isobutanol and DEE) fuel model whose oxidation pathways were given by a reaction mechanism with 177 species and 796 reactions. The key advantage of six-stroke engine operation is the ability to switch the combustion mode among kinetical controlled mode (KCM), kinetically-driven mixing control mode (K-MCM) and mixing controlled mode (MCM) in the second power stroke (PS2) providing a wider
Purushothaman, Ashwin KarthikRa, YoungchulHa, Kyoung PyoZhu, ShengrongUllal, Ankith
The water droplet erosion (WDE) on high-speed rotating wheels appears in several engineering fields such as wind turbines, stationary steam turbines, fuel cell turbines, and turbochargers. The main reasons for this phenomenon are the high relative velocity difference between the colliding particles and the rotor, as well as the presence of inadequate material structure and surface parameters. One of the latest challenges in this area is the compressor wheels used in turbochargers, which has a speed up to 300,000 rpm and have typically been made of aluminum alloy for decades, to achieve the lowest possible rotor inertia. However, while in the past this component was only encountered with filtered air, nowadays, due to developments in compliance with tightening emission standards, various fluids also collide with the spinning blades, which can cause mechanical damage. One such fluid is the condensed water in the low-pressure exhaust gas recirculation channel (LP-EGR) formulated at cold
Takács, RichárdZsoldos, IbolyaSzentendrei, Dániel
The two-branch exhaust of an asymmetric twin-scroll turbocharged engine are asymmetrically and periodically complicated, which has great impact on turbine matching. In this article, a matching effect of turbine speed parameter on asymmetric twin-scroll turbines based on the exhaust pulse energy weight distribution of a heavy-duty diesel engine was introduced. First, it was built as an asymmetric twin-scroll turbine matching based on exhaust pulse energy distribution. Then, by comparing the average matching point and energy matching points on the corresponding turbine performance map, it is revealed that the turbine speed parameter of energy matching points was a significant deviation from the turbine speed parameter under peak efficiency, which leads to the actual turbine operating efficiency lower than the optimal state. In addition, a turbine speed parameter adjustment strategy was proposed by changing compressor impeller diameters to reveal the effect on turbine matching based on
Jin, JianjiaoZhang, ChenyunWu, LiangqinZhu, HongpingQian, Yuanping
The implementation of TREM/CEV 5 emission norms on farm equipment will bring in cost pressure due to the need for exhaust after treatment systems. This cost increase needs to be reduced by bringing in more efficient and effective processes to shorten the development phase and to provide better fuel efficiencies. In this work ETAS ASCMO Online DoE with Constraint Modelling (ODCM) was applied to execute smart online DoE on a new common rail diesel engine with EGR, whose exact bounds of operation was not available. A Global test plan with ASCMO Static was created without much focus on detailed constraints of engine operation, other than the full load curve. The parameters which were selected were Speed, Torque, Rail Pressure, Main Timing, EGR Valve Position, Pilot Separation and Quantity and Post Quantity and Separation. For these parameters, the safe operating bounds were not available. This ASCMO Static test plan is automated and executed on engine test cell with ETAS INCAFlow. ODCM at
Paulraj, Lemuel SrinivasanVarsha, AnuroopaKaradi, SubramanyaKumar, Devendra
Various emission and fuel economy norms for passenger cars have been introduced by the government worldwide. In India, meeting each revision of the Bharat Stage (BS) emission standards and Corporate Average Fuel Economy (CAFE) norms is challenging, and requires the incorporation of new technologies into IC engines. One such technology used in gasoline engines is Exhaust gas recirculation (EGR). The entry of dust particles into the EGR system makes it vulnerable to malfunction. One such fleet validation challenge of EGR valve malfunction has been addressed in this study, where the EGR valve became stuck due to dust entry, leading to engine hunting and stalling. The approach followed for the issue resolution demonstrates a method of developing an EGR valve controller for simulating the failure on a bench setup. The controller setup was built around a microcontroller chip that accurately operated the valve with similar logic to that of the vehicle ECU. In addition to operating the valve
Bhatt, PanchamKumar, KrishanKumar, Sahil
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