Post-Combustion In-Cylinder Vaporization During Cranking and Startup in a Port-Fuel–Injected Spark Ignition Engine

2005 ◽  
Vol 128 (2) ◽  
pp. 397-402 ◽  
Author(s):  
Jim S. Cowart
Keyword(s):  
Combustion Chamber ◽  
Liquid Fuel ◽  
Combustion Process ◽  
Spark Ignition ◽  
Liquid Films ◽  
Spark Ignition Engine ◽  
Fuel Vapor ◽  
Intake Port ◽  
Warm Up ◽  
Flame Ionization

During port-fuel–injected (PFI) spark-ignition (SI) engine startup and warm-up fuel accounting continues to be a challenge. Excess fuel must be injected for a near stoichiometric combustion charge. The “extra” fuel that does not contribute to the combustion process may stay in the intake port or as liquid films on the combustion chamber walls. Some of this combustion chamber wall liquid fuel is transported to the engine’s oil sump and some of this liquid fuel escapes combustion and evolves during the expansion and exhaust strokes. Experiments were performed to investigate and quantify this emerging in-cylinder fuel vapor post-combustion cycle by cycle during engine startup. It is believed that this fuel vapor is evaporating from cylinder surfaces and emerging from cylinder crevices. A fast in-cylinder diagnostic, the fast flame ionization detector, was used to measure this behavior. Substantial post-combustion fuel vapor was measured during engine startup. The amount of post-combustion fuel vapor that develops relative to the in-cylinder precombustion fuel charge is on the order of one for cold starting (0 °C) and decreases to ∼13 for hot starting engine cycles. Fuel accounting suggests that the intake port puddle forms quickly, over the first few engine cranking cycles. Analysis suggests that sufficient charge temperature and crevice oxygen exists to at least partially oxidize the majority of this post-combustion fuel vapor such that engine out hydrocarbons are not excessive.

Two-Stage Lean-Burn Combustion Inside a Natural-Gas Spark-Ignition Engine With a Bowl-in-Piston Chamber

2019 ◽  
Author(s):  
Jinlong Liu ◽  
Cosmin E. Dumitrescu
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Combustion Process ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Intake Manifold ◽  
Hydrocarbon Emissions ◽  
Fuel Injector ◽  
Unburned Hydrocarbon ◽  
Piston Chamber

Abstract The conversion of existing diesel engines to spark ignition (SI) operation by adding a low-pressure injector in the intake manifold for fuel delivery and replacing the original high-pressure fuel injector with a spark plug to initiate and control the combustion process can reduce U.S. dependence on petroleum imports and increase natural gas (NG) applications in heavy-duty transportation sectors. Since the conventional diesel combustion chamber (i.e., flat-head-and-bowl-in-piston-chamber) creates high turbulence, the converted NG SI engine can operate leaner with stable and repeatable combustion process. However, existing literatures point to a long late-combustion duration and increased unburned hydrocarbon emissions in such retrofitted engines that maintained the original combustion chamber. Consequently, the main objective of this paper was to report recent findings of NG combustion characteristics inside a bowl-in-piston combustion chamber that will add to the general understanding of the phenomena. The new results indicated that the premixed NG burn inside the bowl-in-piston combustion chamber will separate into a bowl-burn and a squish-burn processes in terms of burning location and timing. The slow burning event in the squish region explains the low slope of the burn rate towards the end of combustion in existing studies (hence the longer late-combustion period). In addition, the less-favorable conditions for the combustion in the squish region explained the increased carbon monoxide and unburned hydrocarbon emissions.

Analysis of Thermal Efficiency in a Hydrogen Premixed Spark Ignition Engine

1999 ◽  
Author(s):  
Toshio Shudo ◽  
Yasuo Nakajima ◽  
Takayuki Futakuchi
Keyword(s):  
Combustion Chamber ◽  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Methane Combustion ◽  
Spark Ignition ◽  
Hydrogen Combustion ◽  
Spark Ignition Engine ◽  
Chamber Wall ◽  
Flame Velocity

Abstract Hydrogen has higher flame velocity and smaller quenching distance than hydrocarbon fuels, and is supposed to have special characteristics in combustion process of internal combustion engines. In this research, contributors to thermal efficiency in a hydrogen premixed spark ignition engine were analyzed and compared with methane combustion. Results showed hydrogen combustion had higher cooling loss to combustion chamber wall, and thermal efficiency of hydrogen combustion was mainly dominated by both cooling loss to combustion chamber wall and degree of constant volume combustion.

Potential of alcohol fuels in active and passive pre-chamber applications in a passenger car spark-ignition engine

2021 ◽  
pp. 146808742110531
Author(s):  
Patrick Burkardt ◽  
Christian Wouters ◽  
Stefan Pischinger
Keyword(s):  
Combustion Chamber ◽  
Alternative Fuels ◽  
Direct Injection ◽  
Combustion Process ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Passenger Car ◽  
Excess Air ◽  
Lean Limit ◽  
Alcohol Fuels

Both the shift from fossil to alternative fuels and the implementation of a pre-chamber combustion system allow for an increase in the efficiency of an internal combustion engine through optimizing its combustion process, while simultaneously reducing the engine-out emissions. The combination of alcohol-based fuels and pre-chamber combustion concepts has not been investigated on spark-ignition engines with high compression ratios in a passenger car size. This study presents investigations to show the potential in maximum achievable lean limit and net indicated efficiency. In particular, we present investigations of two alternative alcohol fuels on a direct-injection spark-ignition single-cylinder research engine for passenger car applications with a compression ratio of 16.4. The engine was operated with both an active and a passive pre-chamber, and the experimental results were compared to those of conventional spark-ignition operation. Direct injection was used for both the main combustion chamber and the pre-chamber. Methanol and ethanol were used as fuels for the main combustion chamber, whereas exclusively ethanol was used for the pre-chamber fueling. The performance of the alcohol fuels in all combustion configurations was evaluated in both part-load and high-load conditions. In particular, investigations of the combustion behavior over a variation of the excess air ratio at indicated mean effective pressures of 6 and 15 bar were performed. It can be concluded that with the use of methanol as fuel for the main combustion chamber, both higher excess air ratios and higher indicated efficiencies were achieved compared to the use of ethanol as the main combustion chamber fuel. In particular, a maximum net indicated efficiency of 48% at an excess air ratio of 2.0 was achieved with methanol. Moreover, active pre-chamber operation extended the lean limit to an excess air ratio of 2.3 compared to the maximum lean limit of 1.7 in passive pre-chamber operation.

scholarly journals Simulation of liquefied petroleum gas jet in combustion chamber of spark ignition engine

2002 ◽  
Vol 24 (4) ◽  
pp. 209-218
Author(s):  
Bui Van Ga ◽  
Duong Viet Dung ◽  
Tran Van Nam
Keyword(s):  
Combustion Chamber ◽  
Direct Injection ◽  
Combustion Process ◽  
Spark Ignition ◽  
Velocity Fields ◽  
Spark Ignition Engine ◽  
Liquefied Petroleum Gas ◽  
Surrounding Environment ◽  
Mixture Preparation ◽  
Direct Injection Spark Ignition

Based on the mathematical validated by experimental data, the present paper introduces the evolution of concentration and velocity fields of Liquefield Petroleum Gas (LPG) jet in combustion chamber of spark ingnition enegine under effects of injection conditions and surrounding environment. The results allow us to predict the development of jet for an efficient organization of mixture preparation and combustion process in LPG direct injection spark ignition engine

scholarly journals Characterization of radiative heat transfer in a spark-ignition engine through high-speed experiments and simulations

2019 ◽  
Vol 74 ◽  
pp. 61
Author(s):  
Lucca Henrion ◽  
Michael C. Gross ◽  
Sebastian Ferreryo Fernandez ◽  
Chandan Paul ◽  
Samuel Kazmouz ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
High Speed ◽  
Combustion Process ◽  
Spark Ignition ◽  
Infrared Emission ◽  
Spark Ignition Engine ◽  
Local Conditions ◽  
Molecular Gases ◽  
Eddy Simulation ◽  
Molecular Radiation

A combined experimental and Large-Eddy Simulation (LES) study of molecular radiation is presented for combustion in a homogeneous pre-mixed spark-ignition engine. Molecular radiation can account for ~10% of the engine heat loss and could have a noticeable impact on the local conditions within the combustion chamber. The Transparent Combustion Chamber (TCC) engine, a single-cylinder two-valve research engine with a transparent liner and piston for optical access, was used for this study. High-speed infrared emission spectroscopy and radiative post-processing of LES calculations have been performed to gain insight into the timescales and magnitude of radiative emissions of molecular gases during the combustion process. Both the measurements and simulations show significant Cycle-to-Cycle Variations (CCV) of radiative emission. There is agreement in the instantaneous radiative spectrum of experiment and simulation, but the crank-angle development of the radiative spectrum shows disagreement. The strengths and limitations of the optical experiments and radiative simulations are seen in the results and suggest pathways for future efforts in characterizing the influence of molecular radiation. In particular, focusing on the relative changes of the spectral features will be important as they contain information about the thermochemical properties of the gas mixture.

Two-Dimensional Temperature Distributions of Combustion Chamber Surfaces in a Firing Spark Ignition Engine

1994 ◽  
Vol 208 (2) ◽  
pp. 99-108 ◽  
Author(s):  
H Zhao ◽  
N Codings ◽  
T Ma
Keyword(s):  
Surface Temperature ◽  
Combustion Chamber ◽  
Thermal Imaging ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Spark Ignition Engine ◽  
Two Dimensional ◽  
Warm Up ◽  
Temperature Distributions ◽  
Head Surface

This paper summarizes the development and application of advanced thermal imaging techniques to a spark ignition engine at the University of Cambridge Department of Engineering. A thermal imaging system is described which is capable of viewing and recording the cylinder head surface temperature and piston surface temperature in a firing spark ignition engine. Two-dimensional temperature distributions of these surfaces were measured both during the engine's warm-up period and steady state operations. The influence of the engine's operating conditions was examined upon the temperature distributions of combustion chamber surfaces during the engine's warm-up period. The effect of spark timings, particularly the onset of knocking combustion on the surface temperatures, has been studied.

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