Comparisons of the Cyclic Variability of Gasoline/Diesel and Ethanol/Diesel Dual-Fuel Combustion Based on a Diesel Engine

Dong, Shijun; Ou, Biao; Cheng, Xiaobei

doi:10.4271/2017-01-5001

Cited by 5 publications

(2 citation statements)

References 35 publications

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“…While RCCI methods are promising, these modes suffer from several technical challenges. First, cycle-to-cycle and cylinder-to-cylinder variations can be more dramatic than in conventional diesel combustion [62,63]. Since fuel and air mixing are critical and high amounts of recirculated exhaust gas are typically leveraged in these modes, small variations in the in-cylinder fuel quantities and gas mixture can lead to significant variations in the combustion process.…”

Section: Challenges With Reactivity Controlled Compression Ignitionmentioning

confidence: 99%

Dual-Fuel Combustion

Kassa¹,

Hall²

2019

The Future of Internal Combustion Engines

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The implementation of a dual-fuel combustion strategy has recently been explored as a means to improve the thermal efficiencies of internal combustion engines while simultaneously reducing their emissions. Dual-fuel combustion is utilized in compression ignition (CI) engines to promote the use of more readily available gaseous fuels or more efficient, advanced combustion modes. Implementing dual-fuel injection technologies on these engines also allows (1) for improved control of the combustion timing by varying the proportion of two simultaneously injected fuels, and (2) for the use of more advanced combustion modes at high load since the two injected fuels ignite in succession reducing the high peak pressures that generally act as a limiting factor. In spark-ignited (SI) engines, the implementation of a dual-fuel combustion strategy serves as an alternative approach to avoid engine knock. The dual-fuel SI engine relies on the simultaneous injection of a low knock resistance and high knock resistance fuel to dynamically adjust the fuel mixture's resistance to knock as required. The dual-fuel SI engine thereby successfully suppresses knock without compromising the engine efficiency. This chapter discusses the technological advancements associated to dual-fuel combustion and the respective gains in fuel efficiency and emissions reductions that have been achieved.

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Section: Challenges With Reactivity Controlled Compression Ignitionmentioning

confidence: 99%

Dual-Fuel Combustion

Kassa¹,

Hall²

2019

The Future of Internal Combustion Engines

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“…Dong et al 34 performed cyclic variability of ethanol/diesel, and the result showed that combustion was sensitive to a premixed ethanol/diesel ratio, especially at low load conditions. Similarly, Dong et al 35 compared cyclic variability of gasoline/diesel and ethanol/diesel fuel combustion and found fluctuations in the combustion of premixed fuels contributed to higher cyclic variation. Gong et al 36 evaluated cycle-to-cycle combustion variations in direct injection spark ignition (DISI) engine fueled with methanol.…”

Section: Introductionmentioning

confidence: 99%

Impact of methane energy fraction on emissions, performance and cyclic variability in low-load dual fuel combustion at early injection timings

Jha

Krishnan

Srinivasan

2019

International Journal of Engine Research

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This work experimentally examines the effect of methane (a natural gas surrogate) substitution on early injection dual fuel combustion at representative low loads of 3.3 and 5.0 bar BMEPs in a single-cylinder compression ignition engine. Gaseous methane fumigated into the intake manifold at various methane energy fractions was ignited using a high-pressure diesel pilot injection at 310 °CA. For the 3.3 bar BMEP, methane energy fraction sweeps from 50% to 90% were performed; while at 5.0 bar BMEP, methane energy fraction sweeps from 70% to 90% were performed. It is observed that minimum methane energy fraction is limited by maximum pressure rise rate leading to knock and maximum methane energy fraction is limited by a high coefficient of variation in netIMEP, which leads to high cyclic variations. For 3.3 bar BMEP, maximum pressure rise rate is 8 bar/°CA at 50% methane energy fraction while at 5 bar BMEP, it is 12 bar/°CA at 70% methane energy fraction. For 3.3 bar BMEP, engine-out NOx emissions decrease by 43 times when methane energy fraction increases from 50% to 90%, and it decreases by nearly 46 times when methane energy fraction increases from 70% to 90% at 5 bar BMEP. Engine-out unburned hydrocarbon emissions increase by nearly 9 times when methane energy fraction increases from 50% to 90% at 3.3 bar BMEP, and it increases by nearly 5 times when methane energy fraction increases from 70% to 90% at 5.0 bar BMEP. Engine-out carbon monoxide emissions increase by nearly 7 times when methane energy fraction increases from 50% to 90% at 3.3 bar BMEP and by nearly 5 times when methane energy fraction increases from 70% to 90% at 5.0 bar BMEP. In addition, cyclic combustion variations at both loads were analyzed to obtain further insights into the combustion process and identify opportunities to further improve fuel conversion efficiencies at low load operation.

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