A new heat release rate (HRR) law for homogeneous charge compression ignition (HCCI) combustion mode

2009 ◽  
Vol 29 (17-18) ◽  
pp. 3654-3662 ◽  
Author(s):  
Miguel Torres García ◽  
Francisco José Jiménez-Espadafor Aguilar ◽  
Tomás Sánchez Lencero ◽  
José Antonio Becerra Villanueva
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Homogeneous Charge Compression Ignition ◽  
Compression Ignition ◽  
Combustion Mode ◽  
Hcci Combustion ◽  
Homogeneous Charge

Effects of Heat Release Mode on Emissions and Efficiencies of a Compound Diesel Homogeneous Charge Compression Ignition Combustion Engine

2005 ◽  
Vol 128 (2) ◽  
pp. 446-454 ◽  
Author(s):  
Wanhua Su ◽  
Xiaoyu Zhang ◽  
Tiejian Lin ◽  
Yiqiang Pei ◽  
Hua Zhao
Keyword(s):  
Heat Release ◽  
Thermal Efficiency ◽  
Homogeneous Charge Compression Ignition ◽  
Experimental Comparison ◽  
Injection Timing ◽  
Compression Ignition ◽  
Multiple Injection ◽  
Hcci Combustion ◽  
Flexible Mode ◽  
Homogeneous Charge

A compound diesel homogeneous charge compression ignition (HCCI) combustion system has been developed based on the combined combustion strategies of multiple injection strategy and a mixing enhanced combustion chamber design. In this work, a STAR-CD based, multidimensional modeling is conducted to understand and optimize the multiple injection processes. The parameters explored included injection timing, dwell time, and pulse width. Insight generated from this study provides guidelines on designing the multipulse injection rate pattern for optimization of fuel-air mixing. Various heat release modes created by different injection strategies are investigated by experimental comparison of combustion efficiency, heat loss, and thermal efficiency. It is demonstrated that the process of fuel evaporation and mixing are strongly influenced by pulse injection parameters. Through control of the parameters, the stratification and autoignition of the premixed mixture, and the heat release mode can be controlled. The dispersed mode of heat release created only by the compound diesel HCCI combustion is a flexible mode in combustion control. The thermal efficiency with this mode can reach approximately to as high as that of conventional diesel combustion, while the NOx and smoke emissions can be reduced simultaneously and remarkably.

Experimental Study on Homogeneous Charge Compression Ignition Combustion With Fuel of Dimethyl Ether and Natural Gas

2005 ◽  
Vol 128 (2) ◽  
pp. 414-420 ◽  
Author(s):  
Mingfa Yao ◽  
Zunqing Zheng ◽  
Jin Qin
Keyword(s):  
Natural Gas ◽  
Heat Release ◽  
Dimethyl Ether ◽  
Flow Rate ◽  
Heat Release Rate ◽  
Release Rate ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Hcci Combustion ◽  
Peak Cylinder Pressure

The homogeneous charge compression ignition (HCCI) combustion fueled by dimethyl ether (DME) and compressed natural gas (CNG) was investigated. The experimental work was carried out on a single-cylinder diesel engine. The results show that adjusting the proportions of DME and CNG is an effective technique for controlling HCCI combustion and extending the HCCI operating range. The combustion process of HCCI with dual fuel is characterized by a distinctive two-stage heat release process. As CNG flow rate increases, the magnitude of peak cylinder pressure and the peak heat release rate in the second stage goes up. As DME flow rate increases, the peak cylinder pressure, heat release rate, and NOx emissions increase while THC and CO emissions decrease.

scholarly journals Performance and Emission Parameters of Homogeneous Charge Compression Ignition (HCCI) Engine: A Review

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3557 ◽  
Author(s):  
M. Mofijur ◽  
M.M. Hasan ◽  
T.M.I. Mahlia ◽  
S.M. Ashrafur Rahman ◽  
A.S. Silitonga ◽  
...  
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Engine Performance ◽  
Spark Ignition ◽  
Emission Characteristics ◽  
Compression Ignition ◽  
Combustion Mode ◽  
Performance And Emission ◽  
Hcci Combustion ◽  
Hcci Engines ◽  
Homogeneous Charge

Strict emission regulations and demand for better fuel economy are driving forces for finding advanced engines that will be able to replace the conventional internal combustion engines in the near future. Homogeneous charge compression ignition (HCCI) engines use a different combustion technique; there are no spark plugs or injectors to assist the combustion. Instead, when the mixtures reach chemical activation energy, combustion auto-ignites in multiple spots. The main objective of this review paper is to study the engine performance and emission characteristics of HCCI engines operating in various conditions. Additionally, the impact of different fuels and additives on HCCI engine performance is also evaluated. The study also introduces a potential guideline to improve engine performance and emission characteristics. Compared to conventional compression ignition and spark ignition combustion methods, the HCCI combustion mode is noticeably faster and also provides better thermal efficiency. Although a wide range of fuels including alternative and renewable fuels can be used in the HCCI mode, there are some limitation/challenges, such as combustion limited operating range, phase control, high level of noise, cold start, preparation of homogeneous charge, etc. In conclusion, the HCCI combustion mode can be achieved in existing spark ignition (SI) engines with minor adjustments, and it results in lower oxides of nitrogen (NOx) and soot emissions, with practically a similar performance as that of SI combustion. Further improvements are required to permit extensive use of the HCCI mode in future.

Residual-effected homogeneous charge compression ignition at a low compression ratio using exhaust reinduction

2003 ◽  
Vol 4 (3) ◽  
pp. 163-177 ◽  
Author(s):  
P. A. Caton ◽  
A. J. Simon ◽  
J. C. Gerdes ◽  
C. F. Edwards
Keyword(s):  
Compression Ratio ◽  
Equivalence Ratio ◽  
Homogeneous Charge Compression Ignition ◽  
Compression Ignition ◽  
Single Digit ◽  
Hcci Combustion ◽  
Actuation System ◽  
Order Of Magnitude ◽  
No Emissions ◽  
Homogeneous Charge

Studies have been conducted to assess the performance of homogeneous charge compression ignition (HCCI) combustion initiated by exhaust reinduction from the previous engine cycle. Reinduction is achieved using a fully flexible electrohydraulic variable-valve actuation system. In this way, HCCI is implemented at low compression ratio without throttling the intake or exhaust, and without preheating the intake charge. By using late exhaust valve closing and late intake valve opening strategies, steady HCCI combustion was achieved over a range of engine conditions. By varying the timing of both valve events, control can be exerted over both work output (load) and combustion phasing. In comparison with throttled spark ignition (SI) operation on the same engine, HCCI achieved 25–55 per cent of the peak SI indicated work, and did so at uniformly higher thermal efficiency. This was accompanied by a two order of magnitude reduction in NO emissions. In fact, single-digit (ppm) NO emissions were realized under many load conditions. In contrast, hydrocarbon emissions proved to be significantly higher in HCCI combustion under almost all conditions. Varying the equivalence ratio showed a wider equivalence ratio tolerance at low loads for HCCI.

Characterizing the cyclic variability of ignition timing in a homogeneous charge compression ignition engine fuelled with n-heptane/iso-octane blend fuels

2008 ◽  
Vol 9 (5) ◽  
pp. 361-397 ◽  
Author(s):  
M Shahbakhti ◽  
C R Koch
Keyword(s):  
Equivalence Ratio ◽  
Homogeneous Charge Compression Ignition ◽  
Coolant Temperature ◽  
Cyclic Variation ◽  
Compression Ignition ◽  
Ignition Timing ◽  
Compression Ignition Engine ◽  
Hcci Combustion ◽  
Cyclic Variations ◽  
Homogeneous Charge

The cyclic variations of homogeneous charge compression ignition (HCCI) ignition timing is studied for a range of charge properties by varying the equivalence ratio, intake temperature, intake pressure, exhaust gas recirculation (EGR) rate, engine speed, and coolant temperature. Characterization of cyclic variations of ignition timing in HCCI at over 430 operating points on two single-cylinder engines for five different blends of primary reference fuel (PRF), (iso-octane and n-heptane) is performed. Three distinct patterns of cyclic variation for the start of combustion (SOC), combustion peak pressure ( Pmax), and indicated mean effective pressure (i.m.e.p.) are observed. These patterns are normal cyclic variations, periodic cyclic variations, and cyclic variations with weak/misfired ignitions. Results also show that the position of SOC plays an important role in cyclic variations of HCCI combustion with less variation observed when SOC occurs immediately after top dead centre (TDC). Higher levels of cyclic variations are observed in the main (second) stage of HCCI combustion compared with that of the first stage for the PRF fuels studied. The sensitivity of SOC to different charge properties varies. Cyclic variation of SOC increases with an increase in the EGR rate, but it decreases with an increase in equivalence ratio, intake temperature, and coolant temperature.

Active valvetrain for homogeneous charge compression ignition

2005 ◽  
Vol 6 (4) ◽  
pp. 377-397 ◽  
Author(s):  
N Milovanovic ◽  
J G W Turner ◽  
S A Kenchington ◽  
G Pitcher ◽  
D W Blundell
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Cold Start ◽  
Smooth Transition ◽  
Engine Management System ◽  
Compression Ignition ◽  
Load Range ◽  
Hcci Combustion ◽  
Particulate Matter Emissions ◽  
Mode Transitions ◽  
Homogeneous Charge

Homogeneous charge compression ignition (HCCI), also known as controlled autoignition (CAI) or the premixed charge compression ignition (PCCI) engine concept, has the potential to be highly efficient and to produce low NOx, carbon dioxide, and particulate matter emissions. However, it experiences problems with cold start in a gasoline HCCI engine, running at idle and at high loads, which, together with controlling the combustion over the entire speed/load range, limits its practical application. A way to overcome these problems is to operate the engine in ‘hybrid mode’, where the engine operates in HCCI mode at low, medium, and cruising loads and can switch to or from spark ignition (SI) or diesel (CI) mode for a cold start, idle, and higher loads. Such an engine will have frequent changes in engine load and speeds and therefore frequent transitions between HCCI and SI combustion modes. The valvetrain and engine management system (EMS) have to provide a successful control of HCCI mode and a fast and smooth transition keeping all relevant engine parameters within an acceptable range. Consequently, this leads to high demands on the valvetrain and therefore a need for a very high degree of flexibility. The aim of this paper is to present the potential of a fully variable valvetrain (FVVT) system, the Lotus active valvetrain (AVT™), for controlling HCCI combustion and enabling fast and smooth mode transitions in a HCCI/SI engine fuelled with commercially available gasoline (95 RON) and in a HCCI/DI engine fuelled with diesel (50 CN) fuel.

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