Gasoline multiple premixed compression ignition (MPCI): Controllable, high efficiency and clean combustion mode in direct injection engines

2013 ◽  
Vol 14 (1) ◽  
pp. 19-27 ◽  
Author(s):  
H. Q. Yang ◽  
S. J. Shuai ◽  
Z. Wang ◽  
J. X. Wang
Keyword(s):  
High Efficiency ◽  
Direct Injection ◽  
Compression Ignition ◽  
Combustion Mode ◽  
Direct Injection Engines ◽  
Clean Combustion

Optimization of piston bowl and valve system in compression ignition engine fueled with gasoline/diesel/polyoxymethylene dimethyl ethers for high efficiency

2019 ◽  
pp. 146808741986538
Author(s):  
Bowen Li ◽  
Haoye Liu ◽  
Linjun Yu ◽  
Zhi Wang ◽  
Jianxin Wang
Keyword(s):  
Heat Transfer ◽  
Thermal Efficiency ◽  
High Efficiency ◽  
Compression Ignition ◽  
Combustion Mode ◽  
Compression Ignition Engine ◽  
Valve System ◽  
Percentage Points ◽  
Polyoxymethylene Dimethyl Ethers ◽  
Variable Valve

Polyoxymethylene dimethyl ethers, with excellent volatility and oxygen content of up to 49%, have great potential to improve engine performance and emission characteristics. In this study, experiments were carried out in a single-cylinder engine fueled with gasoline/diesel/polyoxymethylene dimethyl ethers blend fuel using multiple premixed compression ignition combustion mode along with engine optimization to exploit the high-efficiency potential. The thermal efficiency was increased by 9.4 percentage points after transforming the combustion mode from conventional diesel mode to gasoline/diesel/polyoxymethylene dimethyl ethers multiple premixed compression ignition mode. A fully variable valve system and a redesigned low-heat-transfer piston were used to further improve the thermal efficiency. The low-heat-transfer piston had a 15% lower area–volume ratio compared with the original ω-type piston. By replacing the original ω-type piston with the low-heat-transfer piston, the heat transfer loss was reduced by 2.29 percentage points and thus indicated thermal efficiency could be increased by 2.37 percentage points, which was up to 50.03%. On the basis of the low-heat-transfer piston, indicated thermal efficiency could be further increased to 51.09% with the application of fully variable valve system due to the longer ignition delay and more premixed combustion. At the same time, NOX emissions could be controlled below 0.4 g/kW·h using high exhaust gas recirculation ratio, which equaled the NOX emission limit of Euro VI standard. Although soot emissions could be increased due to weak turbulence and insufficient intake charge using the low-heat-transfer piston and fully variable valve system, it was still lower than those of the original diesel engines.

Control of a spark ignition homogeneous charge compression ignition mode transition on a gasoline direct injection engine

2007 ◽  
Vol 221 (7) ◽  
pp. 867-875 ◽  
Author(s):  
G Tian ◽  
Z Wang ◽  
Q Ge ◽  
J Wang ◽  
S Shuai
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Direct Injection ◽  
Spark Ignition ◽  
Gasoline Direct Injection ◽  
Compression Ignition ◽  
Combustion Mode ◽  
Key Issues ◽  
Cam Profile ◽  
Negative Valve Overlap ◽  
Homogeneous Charge

The hybrid combustion mode is an ideal operation strategy for a gasoline homogeneous charge compression ignition (HCCI) engine. A stable and smooth spark ignition (SI)/HCCI switch has been an issue in the research on multimode combustion. In this paper, the switch process has two key issues; the cam profile and throttle opening. With the developed two-stage cam system, the valve phase strategy can be switched within one engine cycle, from the normal cam profile for the SI mode to a negative valve overlap (NVO) profile for the HCCI mode, or vice versa. For a smoother and more stable switch, the throttle change was separated from the cam profile switch, which was called the stepped switch. The effect of throttle opening on HCCI combustion was studied, and the results showed that the concept of the stepped switch was reliable. With gasoline direct injection (GDI) the combustion mode switches from both SI and HCCI sides were smooth, rapid, and robust, without any abnormal combustion such as knocking and misfiring.

scholarly journals Combustion stability control of gasoline compression ignition (GCI) under low-load conditions: A review

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Leilei Liu ◽  
Zhifa Zhang ◽  
Yue Liang ◽  
Fan Zhang ◽  
Binbin Yang
Keyword(s):  
High Efficiency ◽  
Stability Control ◽  
Combustion Stability ◽  
Low Temperature Combustion ◽  
Compression Ignition ◽  
Combustion Mode ◽  
Low Load ◽  
Temperature Combustion ◽  
Future Work ◽  
Load Conditions

Abstract With greater energy pressure and stricter emission standards, increasing power output and reducing emissions of engines are simultaneously required. To achieve this, considerable researches are motivated. In recent years, key and representative developments in the field of high-efficiency and clean engines have been carried out. Among them, a low temperature combustion concept called gasoline compression ignition (GCI) is widely considered by universities and research institutions around the world, since it has the potential to achieve ultra-low NO X and soot emissions while maintaining high thermal efficiency. However, GCI combustion mode has certain issues to be solved, such as combustion instability under low-load conditions. Therefore, this paper reviews the experimental, computational and optical studies on the combustion stability control of GCI combustion mode during low loads and describes the recent progress to improve combustion stability as well as points out the future work finally.

SI/HCCI Mode Switching Optimization in a Gasoline Direct Injection Engine Employing Dual Univalve System

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Yintong Liu ◽  
Liguang Li ◽  
Haifeng Lu ◽  
Stephan Schmitt ◽  
Jun Deng ◽  
...  
Keyword(s):  
High Efficiency ◽  
Direct Injection ◽  
Load Condition ◽  
Gasoline Direct Injection ◽  
Mode Switching ◽  
Nox Emissions ◽  
Combustion Mode ◽  
Timing Control ◽  
Main Challenge ◽  
Low Load

Homogeneous charge compression ignition (HCCI) is a feasible combustion mode meeting future stringent emissions regulations, and has high efficiency and low NOX and particle emissions. As the narrow working condition range is the main challenge limiting the industrialization of HCCI, combustion mode switching between SI and HCCI is necessary when employing HCCI in mass production engines. Based on a modified production gasoline direct injection (GDI) engine equipped with dual UniValve system (a fully continuously variable valvetrain system), SI/HCCI mode switching under low load condition is investigated. According to the results, combustion mode switching from SI to HCCI is more complicated than from HCCI to SI. As HCCI requires strict boundary conditions for reliable and repeatable fuel auto-ignition, abnormal combustion easily appears in transition cycle, especially when combustion switches from SI to HCCI. Timing control strategies can optimize the combustion of transition cycles. With the optimization of timing control, the mode switching from SI to HCCI can be completed with only two transition cycles of late combustion, and abnormal combustion can be avoided during the mode switching from HCCI to SI. Under the low load condition, the indicated efficiency reaches 39% and specific NOX emissions drop down to around 1 mg/L/s when the combustion mode is switched to HCCI mode. Compared to SI mode, the indicated efficiency is increased by 10% and the specific NOX emissions are reduced by around 85%.

Experimental analysis of late direct injection combustion mode in a compression-ignition engine fuelled with biodiesel/diesel blends

Energy ◽  
2022 ◽  
Vol 239 ◽  
pp. 121895 ◽  
Author(s):  
José Antonio Vélez Godiño ◽  
Miguel Torres García ◽  
Francisco José Jiménez-Espadafor Aguilar
Keyword(s):  
Experimental Analysis ◽  
Direct Injection ◽  
Compression Ignition ◽  
Combustion Mode ◽  
Compression Ignition Engine

scholarly journals Isolating the effects of reactivity stratification in reactivity-controlled compression ignition with iso-octane and n-heptane on a light-duty multi-cylinder engine

2017 ◽  
Vol 19 (9) ◽  
pp. 907-926 ◽  
Author(s):  
Martin L Wissink ◽  
Scott J Curran ◽  
Greg Roberts ◽  
Mark PB Musculus ◽  
Christine Mounaïm-Rousselle
Keyword(s):  
High Efficiency ◽  
Direct Injection ◽  
Combustion Process ◽  
High Reactivity ◽  
Low Temperature Combustion ◽  
Compression Ignition ◽  
Reactivity Controlled Compression Ignition ◽  
Fundamental Understanding ◽  
Primary Reference ◽  
Primary Reference Fuels

Reactivity-controlled compression ignition (RCCI) is a dual-fuel variant of low-temperature combustion that uses in-cylinder fuel stratification to control the rate of reactions occurring during combustion. Using fuels of varying reactivity (autoignition propensity), gradients of reactivity can be established within the charge, allowing for control over combustion phasing and duration for high efficiency while achieving low NOx and soot emissions. In practice, this is typically accomplished by premixing a low-reactivity fuel, such as gasoline, with early port or direct injection, and by direct injecting a high-reactivity fuel, such as diesel, at an intermediate timing before top dead center. Both the relative quantity and the timing of the injection(s) of high-reactivity fuel can be used to tailor the combustion process and thereby the efficiency and emissions under RCCI. While many combinations of high- and low-reactivity fuels have been successfully demonstrated to enable RCCI, there is a lack of fundamental understanding of what properties, chemical or physical, are most important or desirable for extending operation to both lower and higher loads and reducing emissions of unreacted fuel and CO. This is partly due to the fact that important variables such as temperature, equivalence ratio, and reactivity change simultaneously in both a local and a global sense with changes in the injection of the high-reactivity fuel. This study uses primary reference fuels iso-octane and n-heptane, which have similar physical properties but much different autoignition properties, to create both external and in-cylinder fuel blends that allow for the effects of reactivity stratification to be isolated and quantified. This study is part of a collaborative effort with researchers at Sandia National Laboratories who are investigating the same fuels and conditions of interest in an optical engine. This collaboration aims to improve our fundamental understanding of what fuel properties are required to further develop advanced combustion modes.

Numerical Simulations of Hollow-Cone Injection and Gasoline Compression Ignition Combustion With Naphtha Fuels

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Jihad A. Badra ◽  
Jaeheon Sim ◽  
Ahmed Elwardany ◽  
Mohammed Jaasim ◽  
Yoann Viollet ◽  
...  
Keyword(s):  
Experimental Data ◽  
High Efficiency ◽  
Direct Injection ◽  
Compression Ignition ◽  
Hollow Cone ◽  
Direct Injection Engine ◽  
Technical Paper ◽  
Primary Reference ◽  
Partially Premixed ◽  
Compression Ignition Combustion

Gasoline compression ignition (GCI), also known as partially premixed compression ignition (PPCI) and gasoline direct injection compression ignition (GDICI), engines have been considered an attractive alternative to traditional spark ignition (SI) engines. Lean-burn combustion with the direct injection of fuel eliminates throttle losses for higher thermodynamic efficiencies, and the precise control of the mixture compositions allows better emission performance such as NOx and particulate matter (PM). Recently, low octane gasoline fuel has been identified as a viable option for the GCI engine applications due to its longer ignition delay characteristics compared to diesel and lighter evaporation compared to gasoline fuel (Chang et al., 2012, “Enabling High Efficiency Direct Injection Engine With Naphtha Fuel Through Partially Premixed Charge Compression Ignition Combustion,” SAE Technical Paper No. 2012-01-0677). The feasibility of such a concept has been demonstrated by experimental investigations at Saudi Aramco (Chang et al., 2012, “Enabling High Efficiency Direct Injection Engine With Naphtha Fuel Through Partially Premixed Charge Compression Ignition Combustion,” SAE Technical Paper No. 2012-01-0677; Chang et al., 2013, “Fuel Economy Potential of Partially Premixed Compression Ignition (PPCI) Combustion With Naphtha Fuel,” SAE Technical Paper No. 2013-01-2701). The present study aims to develop predictive capabilities for low octane gasoline fuel compression ignition (CI) engines with accurate characterization of the spray dynamics and combustion processes. Full three-dimensional simulations were conducted using converge as a basic modeling framework, using Reynolds-averaged Navier–Stokes (RANS) turbulent mixing models. An outwardly opening hollow-cone spray injector was characterized and validated against existing and new experimental data. An emphasis was made on the spray penetration characteristics. Various spray breakup and collision models have been tested and compared with the experimental data. An optimum combination has been identified and applied in the combusting GCI simulations. Linear instability sheet atomization (LISA) breakup model and modified Kelvin–Helmholtz and Rayleigh–Taylor (KH-RT) break models proved to work the best for the investigated injector. Comparisons between various existing spray models and a parametric study have been carried out to study the effects of various spray parameters. The fuel effects have been tested by using three different primary reference fuel (PRF) and toluene primary reference fuel (TPRF) surrogates. The effects of fuel temperature and chemical kinetic mechanisms have also been studied. The heating and evaporative characteristics of the low octane gasoline fuel and its PRF and TPRF surrogates were examined.

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