A Two Zone Model of a Single Cylinder HCCI Engine for Control Applications

2008 ◽  
Author(s):  
Varun Tandra ◽  
Nilabh Srivastava
Keyword(s):  
Zone Model ◽  
Ignition Timing ◽  
Control Laws ◽  
Single Cylinder ◽  
First Law Of Thermodynamics ◽  
Hcci Engine ◽  
Hcci Combustion ◽  
Hcci Engines ◽  
Computationally Intensive ◽  
Peak Pressures

This paper presents a first step towards developing a physics-based two-zone model of a single cylinder HCCI engine. Previously control laws were derived by using single zone mathematical models of HCCI combustion; although certain multi-zone models were reported, they were found too complex and unwieldy for the development of fast and efficient controllers for HCCI engines. The present work outlines the modeling approach of a single-cylinder two-zone HCCI engine by incorporating the first law of thermodynamics and temperature and concentration inhomogeneities within the cylinder in order to better predict peak pressures and combustion timings. The results showed good conformity when compared with the computationally intensive multi-zone models. A comparative analysis between the single zone and two-zone models, in the context of predicting cylinder pressures, temperatures, ignition timing is also discussed. Moreover, the effect of external parameters such as speed, and EGR were also evaluated.

A Control-Oriented Two Zone Thermo-Kinetic Model of a Single Cylinder HCCI Engine

2008 ◽  
Author(s):  
Varun Tandra ◽  
Nilabh Srivastava
Keyword(s):  
Kinetic Model ◽  
Compression Ignition Engine ◽  
Control Laws ◽  
Combustion Dynamics ◽  
Single Cylinder ◽  
Hcci Engine ◽  
Hcci Combustion ◽  
Hcci Engines ◽  
Homogeneous Composition ◽  
Start Of Combustion

Over the past two decades, homogeneous charge compression ignition engine technology (HCCI) has aroused a great deal of interest in the automotive sector owing to its ability to generate ultra-low exhaust emissions and to be fuel-flexible. The current work proposes a control-oriented two-zone thermo-kinetic model of such a single cylinder HCCI engine. Earlier control laws were derived by using single zone mathematical models of HCCI combustion; however, these models fail to accurately capture the combustion dynamics of an HCCI engine owing to the assumption of homogeneous composition and temperature in the cylinder. Certain multi-zone models of HCCI engines emphasizing the shortcomings of these single zone models have also been reported in literature. However, such models are far too complex and unwieldy for the development of fast and efficient controllers for HCCI engines. The present work outlines the modeling approach of a single-cylinder two-zone HCCI engine by incorporating the first law of thermodynamics and the temperature and concentration inhomogeneities. The results showed good conformity to those obtained from literature-based multi-zone models. A comparative analysis between the single zone and two-zone models, in the context of predicting cylinder pressures, exhaust gas temperatures, emission concentrations, and start of combustion (SOC), is also discussed.

A Stand-Alone Multi-Zone Model for Combustion in HCCI Engines

2005 ◽  
Author(s):  
Paitoon Kongsereeparp ◽  
Behzad Kashani ◽  
M. David Checkel
Keyword(s):  
Equivalence Ratio ◽  
Homogeneous Charge Compression Ignition ◽  
Residual Fraction ◽  
Zone Model ◽  
Compression Ignition ◽  
Ignition Timing ◽  
Operating Variables ◽  
Hcci Combustion ◽  
Combustion Duration ◽  
Hcci Engines

Because they have the potential for ultra low NOx emissions and high efficiency, Homogeneous Charge Compression Ignition (HCCI) engines have the potential to develop a significant niche. However, a narrow operating range, (bracketed by severe knock and misfire problems), presents a formidable obstacle to developing usable HCCI combustion systems. HCCI combustion is influenced by a complex array of operating variables including fuel octane quality, intake preheating temperature, compression ratio, equivalence ratio, exhaust gas recirculation and engine component temperature. These variables affect the two critical combustion parameters: ignition timing and combustion duration. If these two parameters can be controlled by appropriate settings of the operating variables, a good HCCI combustion scheme could be achieved. Therefore, the theoretical prediction of these two combustion parameters as a function of the key operating variables is necessary for development of HCCI combustion. This paper describes a stand-alone, single-zone and multi-zone combustion model which have been developed for the specific purpose of investigating HCCI combustion control. In the multi-zone model, temperature and composition in each zone were adjusted in order to study the effect of in-homogeneity which is critical to understanding ignition timing and combustion duration in real HCCI engines. The models simulated HCCI combustion using two fuels: hydrogen, (11 species, 23 reactions- from CHEMKIN library), and natural gas, (53 species, 325 reactions- from GRI mech). The capabilities of the two models to predict ignition timing, combustion duration and peak pressure were verified against experimental and simulation results of Fiveland et al [2, 11]. The models were then used to study the effect of different in-homogeneity levels of equivalence ratio, intake temperature and residual fraction. The single zone model could only predict ignition timing while the multi-zone model shows the capability to mimic realistic HCCI combustion phenomena. The study showed that some degree of in-homogeneity is critical to predicting performance of the homogeneous charge compression ignition engine. Further, stratification of equivalence ratio was relatively ineffective at changing combustion while stratification of mixture temperature was very effective. Stratification of the residual fraction proved to be the most promising method of controlling combustion parameters and the mechanism was primarily thermal.

scholarly journals A thermo-kinetic model base study on natural gas HCCI engine response to different initial conditions

2009 ◽  
Vol 136 (1) ◽  
pp. 90-99
Author(s):  
Seyed JAZAYERI ◽  
Jahanian OMID
Keyword(s):  
Natural Gas ◽  
Initial Conditions ◽  
Chemical Species ◽  
Engine Performance ◽  
Zone Model ◽  
Model Base ◽  
Hcci Engine ◽  
Hcci Combustion ◽  
Base Study ◽  
Homogenous Charge Compression Ignition

Homogenous Charge Compression Ignition (HCCI) combustion is a promising concept to reduce engine emmisions and fuel consumption. In this paper, a thermo-kinetic single zone model is developed to study the operation characteristics of a natural gas HCCI engine. The model consists detail chemical kinetics of natural gas oxidation including 325 reactions with 53 chemical species, and is validated with experimental results of reference works. Then, the influence of parameters such as manifold temperature/pressure, and equivalance ratio on incylinder temperature/pressure trends, start of combustion and heat release rate is studied. These results are explained in detail to describe the engine performance thoroughly.

scholarly journals Simulation of predictive kinetic combustion of single cylinder HCCI engine

2020 ◽  
Author(s):  
Ibham Veza ◽  
Mohd Farid Muhamad Said ◽  
Zulkarnain Abdul Latiff ◽  
Mohd Faizal Hasan ◽  
Rifqi Irzuan Abdul Jalal ◽  
...  
Keyword(s):  
Heat Release ◽  
Air Temperature ◽  
Engine Performance ◽  
Zone Model ◽  
Hcci Engine ◽  
Hcci Combustion ◽  
Temperature Heat ◽  
Performance And Emissions ◽  
Improved Performance ◽  
Start Of Combustion

Homogeneous Charge Compression Ignition (HCCI) engine has attracted great attention due to its improved performance and emissions compared to conventional engines. It can reduce both Nitrogen Oxides (NOx) and Particulate Matter (PM) emissions simultaneously without sacrificing the engine performance. However, controlling its combustion phasing remains a major challenge due to the absence of direct control mechanism. The start of combustion is entirely initiated by the chemical reactions inside the combustion chamber, resulted from the compression of its homogeneous mixtures. Varying some critical engine parameters can play a significant role to control the combustion phasing of HCCI engine. This paper investigates the characteristics of HCCI combustion fuelled with n-heptane (C7H16) using single-zone model computational software. The model enabled the combustion object to vary from cycle to cycle. Detailed simulations were conducted to evaluate the effects of air fuel ratio (AFR), compression ratio (CR) and intake air temperature on the in-cylinder pressure and heat release rate. The simulation results showed that the single-zone model was able to predict the two-stage kinetic combustion of HCCI engine; the Low Temperature Heat Release (LTHR) and the High Temperature Heat Release (HTHR) regions. It was found that minor changes in AFR, CR and inlet air temperature led to major changes in the HCCI combustion phasing.

Effect of Hydrogen Addition on Methane HCCI Engine Ignition Timing and Emissions Using a Multi-zone Model

2009 ◽  
Vol 22 (3) ◽  
pp. 290-296
Author(s):  
Zi-han Wang ◽  
Chun-mei Wang ◽  
Hua-xin Tang ◽  
Cheng-ji Zuo ◽  
Hong-ming Xu
Keyword(s):  
Zone Model ◽  
Ignition Timing ◽  
Hydrogen Addition ◽  
Hcci Engine

Numerical Analysis of Biogas Composition Effects on Combustion Parameters and Emissions in Biogas Fueled HCCI Engines for Power Generation

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Iván D. Bedoya ◽  
Samveg Saxena ◽  
Francisco J. Cadavid ◽  
Robert W. Dibble
Keyword(s):  
Numerical Analysis ◽  
Power Output ◽  
Numerical Results ◽  
Combustion Stability ◽  
Absolute Pressure ◽  
Nox Emissions ◽  
Model Simulations ◽  
Hcci Engine ◽  
Hcci Combustion ◽  
Hcci Engines

This study investigates the effects of biogas composition on combustion stability for a purely biogas fueled homogeneous charge compression ignition (HCCI) engine. Biogas is one of the most promising renewable fuels for combined heat and power systems driven by internal combustion engines. However, the high content of CO2 in biogas composition leads to low thermal efficiencies in spark ignited and dual fuel compression ignited engines. The study is divided into two parts: First experimental results on a biogas-fueled HCCI engine are used to illustrate the effects of intake conditions on combustion stability, and second a simulation methodology is used to investigate how biogas composition impacts combustion stability at constant intake conditions. Experimental analysis of a four cylinder, 1.9 L Volkswagen TDI diesel engine shows that biogas-HCCI combustion exhibits high gross indicated mean effective pressure (close to 8 bar), high gross indicated efficiency (close to 45%), and ultralow NOx emissions below the US2010 limit (0.27 g/kWh). An inlet absolute pressure of 2 bar and inlet temperature of 473 K (200 °C) were required for allowing HCCI combustion with a biogas composition of 60% CH4 and 40% CO2 on a volumetric basis. However, slight changes in inlet pressure and temperature caused large changes in cycle-to-cycle variations at low equivalence ratios and large changes in ringing intensity at high equivalence ratios. Numerical analysis of biogas-HCCI combustion is carried out with a sequential methodology that includes one-zone model simulations, computational fluid dynamics (CFD) analysis, and 12-zones model simulations. Numerical results for varied biogas composition show that at high load limit, higher contents of CH4 in biogas composition allow advanced combustion and increased burning rates of the biogas air mixture. Higher contents of CO2 in biogas composition allow lowered ringing intensities with moderate decrease in the indicated efficiency and power output. NOx emissions are not highly affected by biogas composition, while CO and unburned hydrocarbons (HC) emissions tend to increase with higher contents of CO2. According with the numerical results, biogas composition is an effective strategy to control the onset of combustion and combustion phasing of HCCI engines running biogas, allowing more stabilized combustion at low equivalence ratios and safe operation at high equivalence ratios. The main advantages of using biogas-fueled HCCI engines in CHP systems are the low sensitivity of power output and indicated efficiency to biogas composition, as well as the ultralow NOx emissions achieved for all tested compositions.

LQR-Based Control of a Two Zone HCCI Engine Model

2008 ◽  
Author(s):  
Varun Tandra ◽  
Nilabh Srivastava
Keyword(s):  
Environmental Concern ◽  
Research Effort ◽  
Engine Performance ◽  
Linear Quadratic Regulator ◽  
Current Debate ◽  
Zone Model ◽  
Compression Ignition ◽  
Linear Quadratic ◽  
Hcci Engine ◽  
Peak Pressures

With growing environmental concern, automobile energy consumption has become a key element in the current debate on global warming. Over the last two decades, significant research effort has been directed towards developing advanced engine technologies such as HCCI (Homogeneous Charge Compression Ignition) that not only lower the exhaust emissions from an automobile, but also offers reprieve from conventional gasoline/diesel usage by promising fuel-flexibility. HCCI offers better engine performance and reduced emissions by emulating the best features of both CI (compression-ignition) and SI (spark-ignition) engines. However, accurate and reliable combustion control of an HCCI engine is an inherently challenging task. Many single-zone control-oriented HCCI models reported in literature fail to accurately estimate the peak pressures, ignition timings, and especially cylinder temperatures. Although certain multi-zone models of HCCI engines based on detail chemical kinetics and fluid mechanics have been developed, such models are too complex for the synthesis of fast and reliable control laws. Thus, considerable research effort has been directed in the present work to develop a physics-based two-zone model of a single-cylinder HCCI engine accounting for temperature and concentration inhomogeneities within the cylinder for better prediction of peak pressures, combustion timings, and exhaust temperatures. The results obtained were in consonance with the computationally intensive multi-zone models. The nonlinear model for peak pressure, ignition timing and exhaust temperature was linearized about an operating point to facilitate the development of an effective LQR (linear quadratic regulator). The model inputs include variable valve timings to effectively control peak pressures, exhaust temperatures and ignition timings.

A Physics-Based Modeling Approach of a Natural Gas HCCI Engine

2012 ◽  
Author(s):  
Marwa W. AbdelGawad ◽  
Reza Tafreshi ◽  
Reza Langari
Keyword(s):  
Internal Combustion Engines ◽  
Integral Model ◽  
Compression Ignition ◽  
Valve Closure ◽  
Nitric Oxides ◽  
Intake Valve ◽  
Ignition Timing ◽  
Hcci Engine ◽  
Main Challenge ◽  
Hcci Engines

Homogeneous Charge Compression Ignition (HCCI) Engines hold promises of being the next generation of internal combustion engines due to their ability to produce high thermal efficiencies, in addition to low nitric oxides and particulate matter. HCCI combustion is achieved through the auto-ignition of a compressed homogenous fuel-air mixture, thus making it a “fusion” between spark-ignition and compression-ignition engines. The main challenge in developing HCCI engines is the absence of a combustion trigger hence making the control of combustion timing difficult. To be able to control ignition timing, a physics-based model is developed to model the full HCCI engine cycle while taking into consideration cycle-to-cycle transitions. Exhaust Gas Recirculation is used to control combustion timing while the temperature at intake valve closure will serve as the parameter that represents the desired ignition timing. The Modified Knock Integral model defines the necessary relationship between ignition timing and temperature at intake valve closure. Validation of the developed model is performed by determining the ignition timing under varying conditions. Results are shown to be in accordance with data acquired from a single-cylinder model developed using a sophisticated engine simulation program, GT-Power.

scholarly journals Predictive simulation of single cylinder n-butanol HCCI engine

2020 ◽  
Author(s):  
Muhammad Faizullizam Roslan ◽  
Ibham Veza ◽  
Mohd Farid Muhamad Said
Keyword(s):  
Combustion Engine ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Combustion Characteristics ◽  
Critical Parameters ◽  
Zone Model ◽  
Single Cylinder ◽  
Hcci Engine ◽  
Cycle Simulation ◽  
Main Challenge

Homogeneous Charge Compression Ignition (HCCI) is a commonly research new combustion mode due to its advantages over conventional combustion in internal combustion engine such as higher thermal efficiency as well as lower particulate matter (PM) and nitrogen oxides (NOx) emission. However, combustion phasing control difficulty is the main challenge in order to achieve this HCCI combustion due to the absence of direct auto-ignition control. The aim of this study is to investigate the effects of engine load conditions, intake charge temperature and exhaust gas recirculation (EGR) rate numerically on the combustion characteristics of HCCI engine in a single-cylinder and four-stroke engine fuelled with n-butanol. Predictive one-dimensional engine cycle simulation with single-zone model is employed in this study. A chemical kinetic mechanism of n-butanol is used to in this model to capture the chemical reaction process during the combustion. It was found that these parameters play important roles towards the combustion phasing of the HCCI engine as well as the in-cylinder pressure. This HCCI model is able to predict the trend of the combustion characteristics comprehensively with the variation of these critical parameters resulting in a good agreement with previous HCCI studies.

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