High Combustion Temperature for the Reduction of Particulate in Diesel Engines

Kamimoto, Takeyuki; Bae, Myurng-hoan

doi:10.4271/880423

Cited by 238 publications

(103 citation statements)

References 23 publications

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“…Utilizing a high level of Exhaust Gas Recirculation (EGR), the combustion can be performed under low temperature conditions, which are below the NO x formation region. Representative research about the effects of equivalence ratio (Ф) and temperature (T) on the formation of NO x and soot was introduced by Kamimoto [5]. Based on his studies, Sun [6] placed the PCCI, Homogeneous Charge Compression Ignition (HCCI), and traditional diesel operating regimes on the Ф-T chart, as shown in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

CFD Investigation into Diesel PCCI Combustion with Optimized Fuel Injection

et al. 2011

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A multi-pulse injection strategy for premixed charge compression ignition (PCCI) combustion was investigated in a four-valve, direct-injection diesel engine by a computational fluid dynamics (CFD) simulation using KIVA-3V code coupled with detailed chemistry. The effects of fuel splitting proportion, injection timing, spray angles, and injection velocity were examined. The mixing process and formation of soot and nitrogen oxide (NO x ) emissions were investigated as the focus of the research. The results show that the fuel splitting proportion and the injection timing impacted the combustion and emissions significantly due to the considerable changes of the mixing process and fuel distribution in the cylinder. While the spray, inclusion angle and injection velocity at the injector exit, can be adjusted to improve mixing, combustion and emissions, appropriate injection timing and fuel splitting proportion must be jointly considered for optimum combustion performance.Keywords: diesel combustion; KIVA-3V; split injection; premixed charge compression ignition; emissions Acronyms: ATDC = after top dead centre; CO = carbon monoxide; EGR = exhaust gas recirculation; EVC = exhaust valve close; EVO = exhaust valve opening; HCCI = homogeneous charge compression ignition; HC = hydrocarbon; HRR = heat release rate; HSDI = high speed direct injection; HTHR = high temperature heat release; ISFC = indicated specific fuel consumption; IVC = intake valve close; IVO = intake valve OPEN ACCESSEnergies 2011, 4 518 opening; LTC = low temperature combustion; NO x = nitrogen oxides; PCCI = premixed charge compression ignition; PRR = pressure rise rate; TDC = top dead centre; TSC = two-stage combustion; UHC = unburned hydrocarbon

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Section: Introductionmentioning

confidence: 99%

CFD Investigation into Diesel PCCI Combustion with Optimized Fuel Injection

et al. 2011

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“…Consequently, the formaldehyde is especially affected by the chemistry as well as the contour of the map, which delimits the region of reactive mixtures, that is clearly different for rich mixtures between mechanisms. The zone where the reactive mixtures extend in the φ-T map is important because it determines the prediction of pollutant emissions by the model [24]. It is observed that the Wang mechanism shows the most accused slopes in the contour of the map for rich mixtures and, on the contrary, the softest slopes at these mixtures correspond to the Yao mechanism.…”

Section: Resultsmentioning

confidence: 98%

Influence of the chemical mechanism in the frame of diesel-like CFD reacting spray simulations using a presumed PDF flamelet-based combustion model

González

Oliver

Novella

et al. 2017

Proceedings ILASS–Europe 2017. 28th Conference on Liquid Atomization and Spray Systems

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The ability of a computational fluid dynamics (CFD) simulation to reproduce the diesel-like reacting spray ignition process and its corresponding flame structure strongly depends on both the fidelity of the chemical mechanism for reproducing the oxidation of the fuel and also on how the turbulence-chemistry interaction (TCI) is modeled. Therefore, investigating the performance of different chemical mechanisms not only in perfect stirred reactors but directly in the diesel-like spray itself is of great interest in order to evaluate their suitability for being further applied to CFD engine simulations. This research work focuses on applying a presumed probability density function (PDF) unsteady flamelet combustion model to the well-known spray A from the Engine Combustion Network (ECN), using three chemical mechanisms widely accepted by the scientific community as a way to figure out the influence of chemistry in the key characteristics of the combustion process in the frame of diesel-like spray simulations. Results confirm that in spite of providing all of them correct trends for ignition delays (ID) and lift-off lengths (LOL), when comparing with experimental results, the structure of the flame presents noticeable differences, especially in the low and intermediate temperatures and high equivalence ratio regions. Consequently, the selection of the chemical mechanism has an impact on the zones of influence of key species as observed in both spatial coordinates and also in the equivalence ratio-temperature maps. These differences are expected to be relevant considering the implications when coupling pollutant emissions models. The analysis of temperature and oxygen concentration parametric studies evidences how the observed differences are consistent and moderately dependent on the ambient conditions. KeywordsCombustion modeling, Chemical mechanism, Spray A, Flamelet IntroductionThe improvement of the combustion technologies in industrial devices, such as diesel engines, in terms of efficiency and pollutant emissions, evidence that a comprehensive knowledge of the processes involved is mandatory. Between the different processes that concur in the energetic transformation, turbulent non-premixed combustion appears as one of the most relevant. Nevertheless, its modeling is a complex issue due to the different length and time scales of the turbulence, the fuel oxidation and the interaction between them [1]. These considerations point out that for a proper modeling of the turbulent non-premixed combustion two main aspects are essential. The first one is the chemical mechanism, that determines the fuel oxidation, while the second one is the turbulence-chemistry interaction (TCI). Promoted by the need of gaining a very detailed knowledge in these issues in diesel spray conditions, the Engine Combustion Network (ECN) has proposed a set of experiments in controlled conditions that shed light for these concerns by means of experiments and numerical simulations. More particularly, the well-known spray A models a die...

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“…Longer fuel air mixing progress and lower combustion temperatures due to high EGR are beneficial for simultaneously reducing NO x and smoke [12,13], However, considerable penalties of these technologies still exist in the current situation, such as the deterioration of combustion stability and engine performance due to low oxygen in the Energies 2017, 10, 1888 2 of 13 engine cylinder, and more cooling loss of high EGR [14][15][16][17]. Fortunately, the penalties caused by high EGR can be solved by in-cylinder EGR stratification, which modulate the combustion temperature and oxygen distribution to reduce NO x and smoke emissions that are formed under high temperature and a poor oxygen environment [18][19][20].…”

Section: Introductionmentioning

confidence: 99%

Numeric Investigation of Gas Distribution in the Intake Manifold and Intake Ports of a Multi-Cylinder Diesel Engine Refined for Exhaust Gas Stratification

Shen

Cui

et al. 2017

Energies

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Abstract:In-cylinder exhaust gas recirculation (EGR) stratification, generally achieved by supplying EGR asymmetrically into intake ports on a four-valve diesel engine, is sensitive to trapped exhaust gas in the intake manifold and intake ports that is caused by the continuous supply of EGR during the valve-close periods of the intake valves. The subject of this study is to evaluate the distribution of trapped exhaust gas in the diesel intake system using commercial Star-CD software (version 4.22.018). Numeric simulations of the intake flow of fresh air and recycled exhaust in the diesel intake system were initialized following previous experiments that were conducted on a reformed six-cylinder diesel engine by supplying CO 2 instead of EGR to the tangential intake port alone to establish CO 2 stratification in the first cylinder. The distributions of the intake CO 2 in the intake manifold and intake ports under the conditions of 1330 r/min and 50% load with different mass flow rates of CO 2 are discussed. This indicates that CO 2 supplied to one intake port alone would escape to another intake port, which not only weakens the CO 2 stratification by diminishing the mass fraction disparity of the CO 2 between the two intake ports of cylinder 1, but also influences the total mass of CO 2 in the cylinder. There is 4% CO 2 by mass fraction in the intake port without CO 2 supply under the condition that the CO 2 mass flow rate is 5 kg/h during the intake process, and 10% CO 2 under the condition of 50 kg/h.

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High Combustion Temperature for the Reduction of Particulate in Diesel Engines

Cited by 238 publications

References 23 publications

CFD Investigation into Diesel PCCI Combustion with Optimized Fuel Injection

CFD Investigation into Diesel PCCI Combustion with Optimized Fuel Injection

Influence of the chemical mechanism in the frame of diesel-like CFD reacting spray simulations using a presumed PDF flamelet-based combustion model

Numeric Investigation of Gas Distribution in the Intake Manifold and Intake Ports of a Multi-Cylinder Diesel Engine Refined for Exhaust Gas Stratification

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