Effects of the oil and liquid fuel film on hydrocarbon emissions in spark ignition engines

2002 ◽  
Vol 216 (9) ◽  
pp. 759-771 ◽  
Author(s):  
S Yu ◽  
K Min
Keyword(s):  
Liquid Fuel ◽  
Engine Speed ◽  
Spark Ignition Engines ◽  
Fuel Film ◽  
Warm Up ◽  
Oil Film ◽  
Piston Head ◽  
Hc Emissions ◽  
Piston Crevice ◽  
Desorption Mechanism

A model was developed to assess the absorption and desorption of fuel in oil film and in the binary diffusion of oil and fuel films. This was investigated with a parametric study according to engine speed, load and oil film temperature. The results show that Henry's constant, which is related to solubility, is the most dominant parameter in the absorption/desorption mechanism of fuel into the oil film. Under warm-up conditions, engine speed had little influence on the amount of fuel absorbed/desorbed, but when the oil film temperature was low, the quantity of fuel absorbed/desorbed decreased with increasing engine speed. Liquid fuel on the oil film and piston head caused higher hydrocarbon (HC) emissions, and under base conditions (a simulated cold engine), the amount of fuel vaporized from fuel film and desorbed from wetted oil film was 24.5 per cent of the stoichiometric fuel mass. The effect of oil film with liquid fuel was 5.3 times larger than that of oil film without liquid fuel. The amount of fuel that escaped from the piston crevice was 1.3 times larger than that of fuel in the oil film. However, the fuel trapped in the oil film desorbed into the combustion chamber more slowly than the fuel that escaped from the piston crevices under cold engine conditions.

Application of a Phenomenological Model for the Engine-Out Emissions of Unburned Hydrocarbons in Driving Cycles

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Manuel Dorsch ◽  
Jens Neumann ◽  
Christian Hasse
Keyword(s):  
Phenomenological Model ◽  
Combustion Engine ◽  
Combustion Process ◽  
Formation Mechanisms ◽  
Emission Model ◽  
Engine Operation ◽  
Driving Cycles ◽  
Hc Emissions ◽  
Piston Crevice ◽  
Engine Map

In this work, the application of a phenomenological model to determine engine-out hydrocarbon (HC) emissions in driving cycles is presented. The calculation is coupled to a physical-based simulation environment consisting of interacting submodels of engine, vehicle, and engine control. As a novelty, this virtual calibration methodology can be applied to optimize the energy conversion inside a spark-ignited (SI) internal combustion engine at transient operation. Using detailed information about the combustion process, the main origins and formation mechanisms of unburned HCs like piston crevice, oil layer, and wall quenching are considered in the prediction, as well as the in-cylinder postoxidation. Several parameterization approaches, especially, of the oil layer mechanism are discussed. After calibrating the emission model to a steady-state engine map, the transient results are validated successfully against measurements of various driving cycles based on different calibration strategies of engine operation.

scholarly journals Numerical Study of Engine Performance and Emissions for Port Injection of Ammonia into a Gasoline\Ethanol Dual-Fuel Spark Ignition Engine

2021 ◽  
Vol 11 (4) ◽  
pp. 1441
Author(s):  
Farhad Salek ◽  
Meisam Babaie ◽  
Amin Shakeri ◽  
Seyed Vahid Hosseini ◽  
Timothy Bodisco ◽  
...  
Keyword(s):  
Numerical Study ◽  
Combustion Process ◽  
Engine Performance ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Combustion Model ◽  
Dual Fuel ◽  
Spark Ignition Engines ◽  
Performance And Emissions ◽  
Hc Emissions

This study aims to investigate the effect of the port injection of ammonia on performance, knock and NOx emission across a range of engine speeds in a gasoline/ethanol dual-fuel engine. An experimentally validated numerical model of a naturally aspirated spark-ignition (SI) engine was developed in AVL BOOST for the purpose of this investigation. The vibe two zone combustion model, which is widely used for the mathematical modeling of spark-ignition engines is employed for the numerical analysis of the combustion process. A significant reduction of ~50% in NOx emissions was observed across the engine speed range. However, the port injection of ammonia imposed some negative impacts on engine equivalent BSFC, CO and HC emissions, increasing these parameters by 3%, 30% and 21%, respectively, at the 10% ammonia injection ratio. Additionally, the minimum octane number of primary fuel required to prevent knock was reduced by up to 3.6% by adding ammonia between 5 and 10%. All in all, the injection of ammonia inside a bio-fueled engine could make it robust and produce less NOx, while having some undesirable effects on BSFC, CO and HC emissions.

Starting Control Strategy and Experimental Study of CNG Engine

2012 ◽  
Vol 562-564 ◽  
pp. 1044-1047
Author(s):  
Yi Tuan He ◽  
Fan Hua Ma ◽  
Zheng Liang Qi ◽  
Ren Zhe Chen
Keyword(s):  
Experimental Study ◽  
Control Strategy ◽  
Pulse Width ◽  
Engine Speed ◽  
Spark Timing ◽  
Cng Engine ◽  
Hc Emissions ◽  
Starting Control ◽  
Injection Pulse

To reduce the HC emissions of a CNG engine during starting period, starting experiments were carried out on a CNG engine. Injection pulse width (IPW) and spark advance angle () were controlled. The results indicate that wider injection pulse width and earlier spark timing cause higher HC emissions. To guarantee a reliable start and low HC emissions, the engine should start with relatively wider injection pulse width and earlier spark timing, and the injection pulse width and spark advance angle should be reduced gradually after the engine speed is steady.

A Simplified Catalytic Converter Model for Automotive Coldstart Control Applications

2005 ◽  
Author(s):  
Pannag R. Sanketi ◽  
J. Karl Hedrick ◽  
Tomoyuki Kaga
Keyword(s):  
Energy Balance ◽  
Control Volume ◽  
Catalytic Converter ◽  
Oxygen Storage ◽  
Order System ◽  
Thermal Dynamics ◽  
Warm Up ◽  
Automotive Engine ◽  
Static Efficiency ◽  
Hc Emissions

More than three-fourths of the unburned hydrocarbon (HC) emissions in a typical drive cycle of an automotive engine are produced in the initial 2 minutes of operation, commonly known as the coldstart period. Catalyst light-off plays a very important role in reducing these emissions. Model-based paradigm is used to develop a control-oriented, thermodynamics based simple catalyst model for coldstart purposes. It is a modified version of an available model consisting of thermal dynamics and static efficiency maps, the critical modification being in the thermal sub-model. Oxygen storage phenomenon does not play a significant role during the warm-up of the engine. The catalyst is modeled as a second-order system consisting of catalyst brick temperature and temperature of the feedgas flowing through the catalyst as its states. Energy balance of an unsteady flow through a control volume is used to model the feedgas temperature, whereas energy balance of a closed system is used to model the catalyst brick temperature. Wiebe profiles are adopted to empirically model the HC emissions conversion properties of the catalyst as a function of the catalyst temperature and the air-fuel ratio. The static efficiency maps are further extended to include the effects of spatial velocity of the feedgas. Experimental results indicate good agreement with the model estimates for the catalyst warm-up. It is shown that the model represents the system more accurately as compared to the previous model on which it is based and offers a broader scope for analysis.

scholarly journals The performance test of the car catalytic converter in the conditions of urban operation

2020 ◽  
Vol 164 ◽  
pp. 03018 ◽  
Author(s):  
Aleksandr Ivanov ◽  
Oleg Abyzov ◽  
Yurii Galyshev ◽  
Victor Rumyantsev
Keyword(s):  
Urban Areas ◽  
Performance Test ◽  
Catalytic Converter ◽  
Exhaust System ◽  
Continuous Operation ◽  
Spark Ignition Engines ◽  
Warm Up ◽  
Harmful Emissions ◽  
Before And After ◽  
Operational Factors

In the conditions of continuous operation of a car tests of its engine for compliance with the declared environmental class on specialized test benches seem to be quite costly and laborious. Given this circumstance, in this paper a simplified method for verifying the operability of converters is proposed including the assessment of the influence of certain operation modes and some operational factors on the amount of hydrocarbons and carbon monoxide emissions. Efficiency of the converter was estimated by comparing the experimental data on the emissions of these toxic components in the exhaust system before and after the converter. To test the efficiency of the converter, the cold start and warm-up modes of the engine were selected and investigated, as well as several modes close to those typical for testing the engine and car in urban areas according to the European Driving Cycle. As operational factors, typical malfunctions were investigated that often occur during the operation of an engine and significantly increase the amount of harmful emissions. A criterion is proposed for evaluating the performance of the converter and recommendations are given to increase the efficiency of the converter to meet the certain emission standards for cars with spark-ignition engines.

Towards an Innovative Combination of Natural Gas and Liquid Fuel Injection in Spark Ignition Engines

2010 ◽  
Vol 3 (2) ◽  
pp. 196-209 ◽  
Author(s):  
Vivien Delpech ◽  
Jerome Obiols ◽  
Dominique Soleri ◽  
Laurent Mispreuve ◽  
Eric Magere ◽  
...  
Keyword(s):  
Natural Gas ◽  
Liquid Fuel ◽  
Fuel Injection ◽  
Spark Ignition ◽  
Spark Ignition Engines
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