Chemical Composition Modeling of a Two-Zone Control-Oriented Mixing Model for Homogeneous Charge Compression Ignition Engines

2010 ◽  
Author(s):  
Matthew J. McCuen ◽  
Zongxuan Sun ◽  
Guoming Zhu
Keyword(s):  
Chemical Composition ◽  
Homogeneous Charge Compression Ignition ◽  
Deep Understanding ◽  
Mixing Model ◽  
Compression Ignition ◽  
Zone Control ◽  
Hcci Engines ◽  
Unburned Fuel ◽  
And Control ◽  
Homogeneous Charge

Due to the need for clean and efficient automobile propulsion systems, this paper models an important process in the enabling of homogeneous charge compression ignition (HCCI) engines. The need for a deep understanding of charge-residual mixing in residual-affected HCCI engines requires a model of the chemical composition during the mixing process. In this paper, a chemical composition model is developed specifically for a two-zone mixing model to account for important phenomena such as the presence of unburned fuel in the residual exhaust gas. The model is developed as a control-oriented model that can be used for real-time decision making and control. This paper develops the composition model for the major species present, and also presents the method that would be used to include other minor species. The model is simulated for variations in residual gas fraction equivalence ratio, a misfire situation, and its effects on air/fuel ratio.

scholarly journals Analysis of Homogeneous Charge Compression Ignition (HCCI) Engines for Cogeneration Applications

2005 ◽  
Vol 128 (1) ◽  
pp. 16-27 ◽  
Author(s):  
Salvador M. Aceves ◽  
Joel Martinez-Frias ◽  
Gordon M. Reistad
Keyword(s):  
Diesel Engines ◽  
High Efficiency ◽  
Homogeneous Charge Compression Ignition ◽  
Utilization Efficiency ◽  
Small Scale ◽  
Compression Ignition ◽  
Hcci Engines ◽  
Si Engines ◽  
Prime Movers ◽  
Homogeneous Charge

This paper presents an evaluation of the applicability of homogeneous charge compression ignition (HCCI) engines for small-scale cogeneration (<1MWe) in comparison to five previously analyzed prime movers. The five comparator prime movers include stoichiometric spark-ignited (SI) engines, lean burn SI engines, diesel engines, microturbines, and fuel cells. The investigated option, HCCI engines, is a relatively new type of engine that has some fundamental differences with respect to other prime movers. The prime movers are compared by calculating electric and heating efficiency, fuel consumption, nitrogen oxide (NOx) emissions, and capital and fuel costs. Two cases are analyzed. In case 1, the cogeneration facility requires combined power and heating. In case 2, the requirement is for power and chilling. The results show that HCCI engines closely approach the very high fuel utilization efficiency of diesel engines without the high emissions of NOx and the expensive diesel fuel. HCCI engines offer a new alternative for cogeneration that provides a combination of low cost, high efficiency, low emissions, and flexibility in operating temperatures that can be optimally tuned for cogeneration systems. HCCI is the most efficient engine technology that meets the strict 2007 CARB NOx standards for cogeneration engines, and merits more detailed analysis and experimental demonstration.

Modelling and Simulation of Homogeneous Charge Compression Ignition Engine Fueled by Biodiesel

2018 ◽  
Author(s):  
Meshack Hawi ◽  
Mahmoud Ahmed ◽  
Shinichi Ookawara
Keyword(s):  
Heat Release ◽  
Compression Ratio ◽  
Homogeneous Charge Compression Ignition ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Emission Characteristics ◽  
Compression Ignition ◽  
Hcci Engine ◽  
Hcci Engines ◽  
Homogeneous Charge

Homogeneous charge compression ignition (HCCI) is a combustion technology which has received increased attention of researchers in the combustion field for its potential in achieving low oxides of nitrogen (NOx) and soot emission in internal combustion (IC) engines. HCCI engines have advantages of higher thermal efficiency and reduced emissions in comparison to conventional internal combustion engines. In HCCI engines, ignition is controlled by the chemical kinetics, which leads to significant variation in ignition time with changes in the operating conditions. This variation limits the practical range of operation of the engine. Additionally, since HCCI engine operation combines the operating principles of both spark ignition (SI) and compression ignition (CI) engines, HCCI engine parameters such as compression ratio and injection timing may vary significantly depending on operating conditions, including the type of fuel used. As such, considerable research efforts have been focused on establishing optimal conditions for HCCI operation with both conventional and alternative fuels. In this study, numerical simulation is used to investigate the effect of compression ratio on combustion and emission characteristics of an HCCI engine fueled by pure biodiesel. Using a zero-dimensional (0-D) reactor model and a detailed reaction mechanism for biodiesel, the influence of compression ratio on the combustion and emission characteristics are studied in Chemkin-Pro. Simulation results are validated with available experimental data in terms of incylinder pressure and heat release rate to demonstrate the accuracy of the simulation model in predicting the performance of the actual engine. Analysis shows that an increase in compression ratio leads to advanced and higher peak incylinder pressure. The results also reveal that an increase in compression ratio produces advanced ignition and increased heat release rates for biodiesel combustion. Emission of NOx is observed to increase with increase in compression ratio while the effect of compression ratio on emissions of CO, CO2 and unburned hydrocarbon (UHC) is only marginal.

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