A Study of the Ignition and Combustion Process in a Gasoline HCCI Engine Using Port and Direct Fuel Injection(HCCI, Combustion Processes I)

Author(s):  
Michael Guenthner ◽  
Werner Sauter ◽  
Frank Schwarz ◽  
Amin Velji ◽  
Ulrich Spicher
2020 ◽  
Vol 2 (1) ◽  
pp. 7-18
Author(s):  
Jerzy Merkisz ◽  
Maciej Bajerlein ◽  
Paweł Daszkiewicz ◽  
Patryk Urbański

The article contains an analysis of thermodynamic indicators of the CI engine with direct fuel injection. The tested unit was an engine with an unconventional crank-piston configuration, in which at a constant compression ratio, different engine crankshaft control variants were compared. In this article the time ranges in which the piston was located in the TDC were analyzed. Additionally, tests were carried out on a conventional unit for comparative purposes. For the purposes of the work, a piston displacement characteristic was generated in dynamic analysis in SolidWorks Motion. Then, this characteristic was used in the simulations of the combustion process in the AVL Fire program, where the most important thermodynamic indicators of the engine cycle were analyzed.


2017 ◽  
Vol 169 (2) ◽  
pp. 18-23
Author(s):  
Jerzy MERKISZ ◽  
Marek WALIGÓRSKI

The subject of the considerations described in the paper is the problem of early detection of abnormalities and damages during operation process of the turbo diesel engine with small volume displacement and direct fuel injection, which is used in modern LDV vehicles dedicated especially for urban areas, in the context of present and future requirements for a technical object diagnostics, taking into account the criteria of optimizing overall efficiency, toxic compound emission and safety of the object in real conditions of its operation. The paper presents the results of empirical research of vibroacoustic signal application to the diagnostic evaluation of correctness of short-time engine main processes. The evaluation of the combustion process variability from structural and operational abnormalities by using dimensionless estimates of a vibration process was conducted, and functional characteristics necessary to built the diagnostic algorithm in accordance with the requirements of on-board diagnostics were obtained.


Author(s):  
Hongsheng Guo ◽  
W. Stuart Neill ◽  
Wally Chippior ◽  
Hailin Li ◽  
Joshua D. Taylor

Homogeneous charge compression ignition (HCCI) is an advanced low-temperature combustion technology being considered for internal combustion engines due to its potential for high fuel conversion efficiency and extremely low emissions of particulate matter and oxides of nitrogen (NOx). In its simplest form, HCCI combustion involves the auto-ignition of a homogeneous mixture of fuel, air, and diluents at low to moderate temperatures and high pressure. Previous research has indicated that fuel chemistry has a strong impact on HCCI combustion. This paper reports the preliminary results of an experimental and modeling study of HCCI combustion using n-heptane, a volatile hydrocarbon with well known fuel chemistry. A Co-operative Fuel Research (CFR) engine was modified by the addition of a port fuel injection system to produce a homogeneous fuel-air mixture in the intake manifold, which contributed to a stable and repeatable HCCI combustion process. Detailed experiments were performed to explore the effects of critical engine parameters such as intake temperature, compression ratio, air/fuel ratio, engine speed, turbocharging, and intake mixture throttling on HCCI combustion. The influence of these parameters on the phasing of the low-temperature reaction, main combustion stage, and negative temperature coefficient delay period are presented and discussed. A single-zone numerical simulation with detailed fuel chemistry was developed and validated. The simulations show good agreement with the experimental data and capture important combustion phase trends as engine parameters are varied.


2010 ◽  
Vol 140 (1) ◽  
pp. 3-13
Author(s):  
Jacek HUNICZ ◽  
Andrzej NIEWCZAS ◽  
Paweł KORDOS

Homogeneous charge compression ignition (HCCI) is nowadays a leading trend in the development of gasoline internal combustion engines. The application of this novel combustion system will allow to comply with future legislations concerning the exhaust emissions including carbon dioxide. This paper presents a design and implementation of a research engine with a direct fuel injection and the capability of HCCI combustion via an internal gas recirculation and a negative valves overlap (NVO). The technical approach used in the engine allowed an autonomous HCCI operation at variable loads and engine speeds without the need of a spark discharge. Experiments were conducted at a wide range of valve timings providing data which allowed an assessment of a volumetric efficiency and exhaust gas recirculation (EGR) rate. Permissible range of air excess coefficient, providing stable and repeatable operation has also been identified. The use of direct gasoline injection benefited in the improvement of the start of the combustion (SOC) and heat release rate control via the injection timing.


Author(s):  
Changhee Lee ◽  
Jaewoo Jung ◽  
Kihyung Lee

Currently, for the serious air pollution and global warming effect caused by the substance released from the present vehicle, it is expected that the regulatory requirements for the emission will become more stringent. A new concept of the combustion technology that can reduce the NOx and PM related to combustion is urgently needed. To cope with such social demands, many developed countries are efforts to develop the environment friendly vehicle engine at the national lever in order to satisfy with strengthening emission control. As a main combustion technology among new combustion technology for the new generation engine, the homogenous charge compression engine (HCCI) is expanding its application range by employing multiple combustion mode, catalyst, direct fuel injection and partially premixed combustion. In this paper, a multi-injection method in order to apply the HCCI combustion method without mainly altering engine specifications and practicality by referring to the results of the HCCI engine was investigated. Applied with forced charging, exhaust gas recirculation (EGR) and compression ratio change, it was evaluated to the possibility of securing optimum fuel economy and emission reduction in the IMEP 0.8 MPa range.


2017 ◽  
Vol 169 (2) ◽  
pp. 137-140
Author(s):  
Michał GĘCA ◽  
Jacek HUNICZ ◽  
Piotr JAWORSKI

Despite the fact that HCCI engines are distinguished by mixture homogeneity, some degree of stratification always appears inside a combustion chamber. It is especially applied to residual effect engines utilizing negative valve overlap. Mixture stratification is a result of the imperfect mixing of fresh air with trapped residuals. Direct fuel injection introduces stratification as well, due to fuel vaporization. As a consequence, the temperature within the combustion chamber is uneven. Thermal stratification affects auto-ignition timing and combustion evolution in a high extent. The purpose of this study was to evaluate a degree of thermal stratification in HCCI engine utilizing negative valve overlap. Investigations were performed using three-dimensional CFD model of the combustion system, made by using AVL FIRE software. Simulations were realized for various timings of fuel injection into the cylinder. It was found that fuel injection timing had a significant effect on the thermal stratification and resulting auto-ignition timing.


Sign in / Sign up

Export Citation Format

Share Document