Effects of passive pre-chamber jet ignition on combustion and emission at gasoline engine

2021 ◽  
Vol 13 (12) ◽  
pp. 168781402110671
Author(s):  
Wei Duan ◽  
Zhaoming Huang ◽  
Hong Chen ◽  
Ping Tang ◽  
Li Wang ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Gasoline Engine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Spark Ignition ◽  
Combustion Stability ◽  
Intake Valve ◽  
Part Load ◽  
Significant Difference ◽  
Valve Opening

Pre-chamber jet ignition is a promising way to improve fuel consumption of gasoline engine. A small volume passive pre-chamber was tested at a 1.5L turbocharged GDI engine. Combustion and emission characteristics of passive pre-chamber at low-speed WOT and part load were studied. Besides, the combustion stability of the passive pre-chamber at idle operation has also been studied. The results show that at 1500 r/min WOT, compared with the traditional spark ignition, the combustion phase of pre-chamber is advanced by 7.1°CA, the effective fuel consumption is reduced by 24 g/kW h, and the maximum pressure rise rate is increased by 0.09 MPa/°CA. The knock tendency can be relieved by pre-chamber ignition. At part load of 2000 r/min, pre-chamber ignition can enhance the combustion process and improve the combustion stability. The fuel consumption of pre-chamber ignition increases slightly at low load, but decreases significantly at high load. Compared with the traditional spark ignition, the NOx emissions of pre-chamber increase significantly, with a maximum increase of about 15%; the HC emissions decrease, and the highest decrease is about 36%. But there is no significant difference in CO emissions between pre-chamber ignition and spark plug ignition. The intake valve opening timing has a significant influence on the pre-chamber combustion stability at idle operation. With the delay of the pre-chamber intake valve opening timing, the CoV is reduced and can be kept within the CoV limit.

THE STUDY OF THE EFFECT OF INTAKE VALVE TIMING ON ENGINE USING CYLINDER DEACTIVATION TECHNIQUE VIA SIMULATION

2015 ◽  
Vol 77 (8) ◽  
Author(s):  
S. F. Zainal Abidin ◽  
M. F. Muhamad Said ◽  
Z. Abdul Latiff ◽  
I. Zahari ◽  
M. Said
Keyword(s):  
Fuel Consumption ◽  
Internal Combustion Engines ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Intake Valve ◽  
Cylinder Deactivation ◽  
Part Load ◽  
Engine Model ◽  
Engine Efficiency ◽  
Load Conditions

There are many technologies that being developed to increase the efficiency of internal combustion engines as well as reducing their fuel consumption.  In this paper, the main area of focus is on cylinder deactivation (CDA) technology. CDA is mostly being applied on multi cylinders engines. CDA has the advantage to improve fuel consumption by reducing pumping losses at part load engine conditions. Here, the application of CDA on 1.6L four cylinders gasoline engine is studied. One-dimensional (1D) engine modeling work is performed to investigate the effect of intake valve strategy on engine performance with CDA. 1D engine model is constructed based on the 1.6L actual engine geometries. The model is simulated at various engine speeds at full load conditions. The simulated results show that the constructed model is well correlated to measured data. This correlated model is then used to investigate the CDA application at part load conditions. Also, the effects on the in-cylinder combustion as well as pumping losses are presented. The study shows that the effect of intake valve strategy is very significant on engine performance. Pumping losses is found to be reduced, thus improve fuel consumption and engine efficiency.

A numerical procedure for the calibration of a turbocharged spark-ignition variable valve actuation engine at part load

2016 ◽  
Vol 18 (8) ◽  
pp. 810-823 ◽  
Author(s):  
Fabio Bozza ◽  
Vincenzo De Bellis ◽  
Luigi Teodosio
Keyword(s):  
Fuel Consumption ◽  
Spark Ignition ◽  
Specific Fuel Consumption ◽  
Brake Specific Fuel Consumption ◽  
Valve Closure ◽  
Intake Valve ◽  
Part Load ◽  
Variable Valve Actuation ◽  
Variable Valve ◽  
Valve Actuation

Referring to spark-ignition engines, the downsizing, coupled to turbocharging and variable valve actuation systems are very common solutions to reduce the brake-specific fuel consumption at low-medium brake mean effective pressure. However, the adoption of such solutions increases the complexity of engine control and management because of the additional degrees of freedom, and hence results in a longer calibration time and higher experimental efforts. In this work, a twin-cylinder turbocharged variable valve actuation spark-ignition engine is numerically investigated by a one-dimensional model (GT-Power™). The considered engine is equipped with a fully flexible variable valve actuation system, realizing both a common full-lift strategy and a more advanced early intake valve closure strategy. Refined sub-models are used to describe turbulence and combustion processes. In the first stage, one-dimensional engine model is validated against the experimental data at full and part load. The validated model is then integrated in a multipurpose commercial optimizer (modeFRONTIER™) with the aim to identify the engine calibration that minimizes brake-specific fuel consumption at part load. In particular, the decision parameters of the optimization process are the early intake valve closure angle, the throttle valve opening, the turbocharger setting and the spark timing. Proper constraints are posed for intake pressure in order to limit the gas-dynamic noise radiated at the intake mouth. The adopted optimization approach shows the capability to reproduce with good accuracy the experimentally identified calibration. The latter corresponds to the numerically derived Pareto frontier in brake mean effective pressure–brake specific fuel consumption plane. The optimization also underlines the advantages of an engine calibration based on a combination of early intake valve closure strategy and intake throttling rather than a purely throttle-based calibration. The developed automatic procedure allows for a ‘virtual’ calibration of the considered engine on completely theoretical basis and proves to be very helpful in reducing the experimental costs and the engine time-to-market.

Combustion Characteristics of Stratified Mixture in Lean-Burn LPG Direct-Injection Engine With Spray-Guided Combustion System

2014 ◽  
Author(s):  
Cheolwoong Park ◽  
Seungmook Oh ◽  
Taeyoung Kim ◽  
Heechang Oh ◽  
Choongsik Bae
Keyword(s):  
Fuel Consumption ◽  
Compression Ratio ◽  
Fuel Economy ◽  
Direct Injection ◽  
Combustion Process ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Direct Injection Engine ◽  
Brake Mean Effective Pressure

Today, we are faced with the problems of global warming and fossil fuel depletion, and they have led to the enforcement of new emissions regulations. Direct-injection spark-ignition engines are a very promising technology that can comply with the new regulations. These engines offer the advantages of better fuel economy and lower emissions than conventional port-injection engines. The use of LPG as the fuel reduces carbon emissions because of its vaporization characteristics and the fact that it has lower carbon content than gasoline. An experimental study was carried out to investigate the combustion process and emission characteristics of a 2-liter spray-guided LPG direct-injection engine under lean operating conditions. The engine was operated at a constant speed of 2000 rpm under 0.2-MPa brake mean effective pressure, which corresponds to a common operation point of a passenger vehicle. Combustion stability, which is the most important component of engine performance, is closely related to the operation strategy and it significantly influences the degree of fuel consumption reduction. In order to achieve stable combustion with a stratified LPG mixture, an inter-injection spark ignition (ISI) strategy, which is an alternative control strategy to two-stage injection, was employed. The effects of the compression ratio on fuel economy were also assessed; due to the characteristics of the stratified LPG mixture, the fuel consumption did not reduce when the compression ratio was increased.

scholarly journals Effect of Various Ignition Timings on Combustion Process and Performance of Gasoline Engine

2017 ◽  
Vol 65 (2) ◽  
pp. 545-554 ◽  
Author(s):  
Lukáš Tunka ◽  
Adam Polcar
Keyword(s):  
Gasoline Engine ◽  
Mixture Fraction ◽  
Combustion Process ◽  
Control Unit ◽  
Spark Ignition Engine ◽  
Combustion Stability ◽  
Ignition Timing ◽  
Combustion Duration ◽  
Significant Difference ◽  
Engine Power

This article deals with the effect of the ignition timing on the output parameters of a spark-ignition engine. The main assessed parameters include the output parameters of the engine (engine power and torque), cylinder pressure variation, heat generation and burn rate. However, the article also discusses the effect of the ignition timing on the temperature of exhaust gases, the indicated mean effective pressure, the combustion duration, combustion stability, etc. All measurements were performed in an engine test room in the Department of Technology and Automobile Transport at Mendel University in Brno, on a four-cylinder AUDI engine with a maximum power of 110 kW, as indicated by the manufacturer. To control and change the ignition timing of the engine, a fully programmable Magneti Marelli control unit was used. The experimental measurements were performed on 8 different ignition timings, from 18 °CA to 32 °CA BTDC at wide throttle open and a constant engine speed (2500 rpm), with a stoichiometric mixture fraction. The measurement results showed that as the ignition timing increases, the engine power and torque also increase. The increase in these parameters is a reflection of higher pressure in the cylinder, the maximum value of which is achieved at a higher ignition timing near top dead centre in thepower stroke. In these conditions we can expect higher engine efficiency. It was also found that the combustion is more stable with a higher value of ignition timing. No significant difference was found in the combustion duration.

Combustion Characteristics of Stratified Mixture in Lean-Burn Liquefied Petroleum Gas Direct-Injection Engine With Spray-Guided Combustion System

2015 ◽  
Vol 138 (7) ◽  
Author(s):  
Cheolwoong Park ◽  
Seungmook Oh ◽  
Taeyoung Kim ◽  
Heechang Oh ◽  
Choongsik Bae
Keyword(s):  
Fuel Consumption ◽  
Compression Ratio ◽  
Fuel Economy ◽  
Direct Injection ◽  
Combustion Process ◽  
Spark Ignition ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Liquefied Petroleum Gas ◽  
Direct Injection Engine

Today, we are faced with the problems of global warming and fossil fuel depletion, and they have led to the enforcement of new emissions regulations. Direct-injection spark-ignition engines are a very promising technology that can comply with the new regulations. These engines offer the advantages of better fuel economy and lower emissions than conventional port-injection engines. The use of liquefied petroleum gas (LPG) as the fuel reduces carbon emissions because of its vaporization characteristics and the fact that it has lower carbon content than gasoline. An experimental study was carried out to investigate the combustion process and emission characteristics of a 2 l spray-guided LPG direct-injection engine under lean operating conditions. The engine was operated at a constant speed of 2000 rpm under 0.2 MPa brake mean effective pressure (BMEP), which corresponds to a common operation point of a passenger vehicle. Combustion stability, which is the most important component of engine performance, is closely related to the operation strategy and it significantly influences the degree of fuel consumption reduction. In order to achieve stable combustion with a stratified LPG mixture, an interinjection spark ignition (ISI) strategy, which is an alternative control strategy to two-stage injection, was employed. The effects of the compression ratio on fuel economy were also assessed; due to the characteristics of the stratified LPG mixture, the fuel consumption did not reduce when the compression ratio was increased.

Investigation of Intake Valve Strategy on the Cylinder Deactivation Engine

2016 ◽  
Vol 819 ◽  
pp. 459-465
Author(s):  
Mohd Farid Muhamad Said ◽  
Zulkarnain Abdul Latiff ◽  
Shaiful Fadzil Zainal Abidin ◽  
Izzarief Zahari
Keyword(s):  
Fuel Consumption ◽  
Internal Combustion Engines ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Research Area ◽  
Intake Valve ◽  
Cylinder Deactivation ◽  
Part Load ◽  
Main Research ◽  
Load Conditions

There are many technologies that being developed to increase the efficiency of internal combustion engines as well as reducing their fuel consumption. In this paper, the main research area is focus on cylinder deactivation (CDA) technology. CDA mostly being applied on multi cylinders engines. CDA has the advantage in improving fuel consumption by reducing pumping losses at part load engine conditions. Here, the application of CDA on 1.6L four cylinders gasoline engine was studied. One-dimensional (1D) engine modeling is performed to investigate the effect of intake valve strategy on engine performance with CDA. 1D engine model is constructed according to the 1.6L actual engine geometries. The model is simulated at various engine speeds at full load conditions. The simulated results show that the constructed model is well correlated to measured data. This correlated model used to investigate the CDA application at part load conditions. Also, the effects on the in-cylinder combustion as well as pumping losses are presented. The study shows that the effect of intake valve strategy is very significant on engine performance. Pumping losses is found to be reduced, thus improving fuel consumption and engine efficiency.

Tumble Flow Measurements Using Three Different Methods and Its Effects on Fuel Economy and Emissions

2006 ◽  
Author(s):  
Myoungjin Kim ◽  
Sihun Lee ◽  
Wootae Kim
Keyword(s):  
Fuel Economy ◽  
High Performance ◽  
Gasoline Engine ◽  
Exhaust Emissions ◽  
Combustion Stability ◽  
Lean Burn ◽  
Flow Measurements ◽  
Part Load ◽  
Gasoline Engines ◽  
Dynamometer Test

In-cylinder flows such as tumble and swirl have an important role on the engine combustion efficiencies and emission formations. In particular, the tumble flow, which is dominant in-cylinder flow in current high performance gasoline engines, has an important effect on the fuel consumptions and exhaust emissions under part load conditions. Therefore, it is important to know the effect of the tumble ratio on the part load performance and optimize the tumble ratio of a gasoline engine for better fuel economy and exhaust emissions. First step in optimizing a tumble flow is to measure a tumble ratio accurately. In this research the tumble flow was measured, compared and correlated using three different measurement methods: steady flow rig, 2-Dimensional PIV, and 3-Dimensional PTV. Engine dynamometer test was performed to find out the effect of the tumble ratio on the part load performance. Dynamometer test results of high tumble ratio engine showed faster combustion speed, retarded MBT timing, higher exhaust emissions, and a better lean burn combustion stability. Lean limit of the baseline engine was expanded from A/F=18:1 to A/F=21:1 by increasing a tumble ratio using MTV.

scholarly journals Numerical investigations on hydrogen-enhanced combustion in ultra-lean gasoline spark-ignition engines

2019 ◽  
pp. 146808741987068 ◽  
Author(s):  
Nicolas Iafrate ◽  
Mickael Matrat ◽  
Jean-Marc Zaccardi
Keyword(s):  
Ignition Delay ◽  
Combustion Process ◽  
Spark Ignition ◽  
Combustion Stability ◽  
Spark Ignition Engines ◽  
Numerical Investigations ◽  
Ignition Delay Times ◽  
Auto Ignition ◽  
Delay Times ◽  
Combustion Speed

Performance of lean-burn gasoline spark-ignition engines can be enhanced through hydrogen supplementation. Thanks to its physicochemical properties, hydrogen supports the flame propagation and extends the dilution limits with improved combustion stability. These interesting features usually result in decreased emissions and improved efficiencies. This article aims at demonstrating how hydrogen can support the combustion process with a modern combustion system optimized for high dilution resistance and efficiency. To achieve this, chemical kinetics calculations are first performed in order to quantify the impacts of hydrogen addition on the laminar flame speed and on the auto-ignition delay times of air/gasoline mixtures. These data are then implemented in the extended coherent flame model and tabulated kinetics of ignition combustion models in a specifically updated version of the CONVERGE code. Three-dimensional computational fluid dynamics engine calculations are performed at λ = 2 with 3% v/v of hydrogen for two operating points. At low load, numerical investigations show that hydrogen enhances the maximal combustion speed and the flame growth just after the spark which is a critical aspect of combustion with diluted mixtures. The flame front propagation is also more isotropic when supported with hydrogen. At mid load, hydrogen improves the combustion speed and also extends the auto-ignition delay times resulting in a better knocking resistance. A maximal indicated efficiency of 48.5% can thus be reached at λ = 2 thanks to an optimal combustion timing.

Understanding the infiuence of valve timings on controlled autoignition combustion in a four-stroke port fuel injection engine

2005 ◽  
Vol 219 (6) ◽  
pp. 807-823 ◽  
Author(s):  
Li Cao ◽  
Hua Zhao ◽  
Xi Jiang ◽  
Navin Kalian
Keyword(s):  
Gas Exchange ◽  
Gasoline Engine ◽  
Fuel Injection ◽  
Exchange Process ◽  
Combustion Process ◽  
Intake Valve ◽  
Time Model ◽  
Port Fuel Injection ◽  
Cycle Simulation ◽  
Controlled Autoignition

Controlled autoignition (CAI) combustion, also known as homogeneous charge compression ignition (HCCI), was achieved through the negative valve overlap approach by using small- lift camshafts. Three-dimensional multicycle engine simulations were carried out in order better to understand the effects of variable intake valve timings on the gas exchange process, mixing quality, CAI combustion, and pollutant formation in a four-stroke port fuel injection (PFI) gasoline engine. Full engine cycle simulation, including complete gas exchange and combustion processes, was carried out over several cycles in order to obtain the stable cycle for analysis. The combustion models used in the present study are a modified shell ignition model and a laminar and turbulent characteristic time model, which can take high residual gas fraction into account. After the validation of the model against experimental data, investigations of the effects of variable intake valve timing strategies on the CAI combustion process were carried out. These analyses show that the intake valve opening (IVO) and intake valve closing (IVC) timings have a strong infiuence on the gas exchange and mixing processes in the cylinder, which in turn affect the engine performance and emissions. Symmetric IVO timing relative to exhaust valve closing (EVC) timing tends to produce a more stratified mixture, earlier ignition timing, and localized combustion, and hence higher NO x and lower unburned HC and CO emissions, whereas retarded IVO leads to faster mixing, a more homogeneous mixture, and uniform temperature distribution.

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