Fuel Chemistry Impacts on Gasoline HCCI Combustion with Negative Valve Overlap and Direct Injection

Shen, Yuehai; King, Ed; Pfahl, Ulrich; Krile, Robert; Slone, Elizabeth; Orban, John; Wright, K.C.

doi:10.4271/2007-01-4105

Cited by 12 publications

(3 citation statements)

References 19 publications

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“…In recent years, the feasibility of different gas trapping methods that enable HCCI combustion at conventional geometric compression ratio and eliminate the need for auxiliary intake air heating has been extensively studied. One common approach is referred to as the negative valve overlap (NVO) method [11,12,13]. In this method, the burned gases trapped inside the cylinder are recompressed and allowed to expand before the intake valve opens.…”

Section: Introductionmentioning

confidence: 99%

Extending the High Load Operating Limit of a Naturally-Aspirated Gasoline HCCI Combustion Engine

Yun¹,

Wermuth²,

Najt³

2010

SAE Int. J. Engines

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Homogenous Charge Compression Ignition (HCCI) combustion offers efficiency improvements compared to conventional gasoline engines. However, due to the nature of HCCI, traditional HCCI combustion can be realized only in a limited operating range. The HCCI operation at high load is limited by excessive combustion noise.In order to maximize the fuel economy benefits of HCCI its operating range needs to be extended to higher loads. In particular, one immediate benefit of an increased load range on the NEDC driving cycle is the avoidance of transitions between SI operation and HCCI operation.In this research a detailed investigation of the fundamental reasons for high combustion noise was performed. Sparkassisted HCCI combustion was found to be a key factor to reduce combustion noise at high load condition. Injection timing for charge cooling, spark timing for the onset of combustion through flame propagation, smaller NVO and higher EGR are the enablers to achieve the appropriate sparkassisted HCCI combustion at high load operation. The high load limit was successfully extended while maintaining good efficiency and complying with emissions regulations.The effect of double injection strategy was also investigated. It is found that even though slight improvement in the tradeoff between combustion noise and combustion stability can be achieved through double injection strategy, fuel consumption is deteriorated due to incomplete combustion.

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Section: Introductionmentioning

confidence: 99%

Extending the High Load Operating Limit of a Naturally-Aspirated Gasoline HCCI Combustion Engine

Yun¹,

Wermuth²,

Najt³

2010

SAE Int. J. Engines

View full text Add to dashboard Cite

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“…In a practical gasoline the n-paraffinic (P) content is 160 usually in the range from 7 to 14 mol.%, while iso-paraffins (I) are found in the range from 29 to 45 mol.% [45]. Paraffins, particularly n-paraffins, have a unique low-temperature chemistry that can lead to knock in SI engines and may facilitate ignition in HCCI engines [59]. The knocking ten-165 dency of n-paraffins increases with the length of the carbon chain, while iso-paraffins present a decreased knock tendency because of the side chains, especially when the methyl groups ( ĊH 3 ) are found in the second from the end or center position of the basic carbon chain [30].…”

Section: Gasoline Surrogatesmentioning

confidence: 99%

A six-compound, high performance gasoline surrogate for internal combustion engines: Experimental and numerical study of autoignition using high-pressure shock tubes

Cancino

Silva

Toni

et al. 2020

Fuel

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“…Multiple scientific experiments and modeling studies have concluded that the fuel chemistry impact on HCCI combustion manifests itself in ignition delay, combustion phasing, and rate of heat release [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. However, most of these studies have focused on [19] single-component fuels and fuel surrogates, which do not constitute a representative sample of the gasoline available at the pump.…”

Section: Introductionmentioning

confidence: 99%

Impact of Refinery Stream Gasoline Property Variation on Load Sensitivity of the HCCI Combustion

Lacey

Filipi

Sathasivam

et al. 2013

Journal of Engineering for Gas Turbines and Power

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The homogeneous charge compression ignition (HCCI) combustion process is highly reliant upon a favorable in-eylinder thermal environment in an engine, for a given fuel. Commercial fuels can differ considerably in composition and autoignition chemistry; hence, strategies intended to bring HCCI to market must account for this fuel variability. To this end, a test matrix consisting of eight gasoline fuels comprised of blends made solely from refineiy streams were run in an e.xperimental, single cylinder HCCI engine. All fuels contained 10% ethanol by volume and were representative of a cross section of fuels one would expect to find at gasoline pumps across the United States. The properties of the fuels were varied according to research octane number (RON), sensitivity (S = RON-MON), and volumetric content of aromatics and olefins. For each fuel, a sweep of load (mass of fuel injected per cycle) was conducted and the intake air temperature was adjusted in order to keep the crank angle of the 50% mass fraction burned point (CA50} constant. By analyzing the amount of temperature compensation required to maintain constant comhustion phasing, it was possihle to determine the sensitivity of HCCI to changes in load for various fuels. In addition, the deviation of fuel properties hrought ahout variations in important engine peiformance metrics like specific fuel consumption. Though the injected energy content per cycle was matched at the haseline point across the test fuel matrix, thermodynamic differences resulted in a spread of specific fuel consumption for the fuels tested.

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Fuel Chemistry Impacts on Gasoline HCCI Combustion with Negative Valve Overlap and Direct Injection

Cited by 12 publications

References 19 publications

Extending the High Load Operating Limit of a Naturally-Aspirated Gasoline HCCI Combustion Engine

Extending the High Load Operating Limit of a Naturally-Aspirated Gasoline HCCI Combustion Engine

A six-compound, high performance gasoline surrogate for internal combustion engines: Experimental and numerical study of autoignition using high-pressure shock tubes

Impact of Refinery Stream Gasoline Property Variation on Load Sensitivity of the HCCI Combustion

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