Wet ethanol in LTC: How water fraction and DTBP affect combustion and intake temperature at naturally aspirated and boosted conditions

Gohn, James; Gainey, Brian; Zainul, Saeed; Lawler, Benjamin

doi:10.1016/j.fuel.2020.117094

Cited by 20 publications

(3 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First-generation kinetically-controlled combustion strategies like homogeneous charge compression ignition (HCCI) demonstrated high-efficiency operation with near-zero NOx and particulate matter (PM) emissions [12]. Wet ethanol can be effectively employed in HCCI [13][14][15]. The heat release process in HCCI is dictated by natural thermal stratification formed from heat transfer during the compression stroke whereby the hottest regions in the cylinder achieve autoignition first, release their heat and further compress and heat the remaining colder regions in the cylinder, resulting in their autoignition.…”

Section: Introductionmentioning

confidence: 99%

High Load Compression Ignition of Wet Ethanol Using a Triple Injection Strategy

et al. 2022

Self Cite

View full text Add to dashboard Cite

Wet ethanol is a biofuel that can be rapidly integrated into the existing transportation sector infrastructure and have an immediate impact on decarbonization. Compared to conventional hydrocarbon fuels, wet ethanol has unique fuel properties (e.g., short carbon chain, oxygenated, high heat of vaporization, no cool-flame reactivity), which can actually improve the efficiency and engine-out emissions of internal combustion engines while decarbonizing. In this work, wet ethanol 80 (80% ethanol, 20% water by mass) was experimentally studied at high loads under boosted conditions in compression ignition to study the tradeoffs in efficiency and emissions based on boosting and injection strategies. Specifically, this work explores the potential of adding a third, mixing-controlled injection at high loads. The results indicate that adding a third, mixing-controlled injection results in combustion stabilization at high loads, where the peak pressure limit of the engine is a constraint that requires combustion phasing to retard. However, since the heat of vaporization of wet ethanol 80 is ~6% of its lower heating value, evaporation of fuel injected near top dead center imposes a thermodynamic efficiency penalty by absorbing heat from the working fluid at a time in the cycle when adding heat produces net work out. Additionally, the mixing-controlled injection increases NOx emissions. Therefore, the amount of fuel injected in the mixing-controlled injection should be limited to only what is necessary to stabilize combustion. Ultimately, by using wet ethanol 80 in a triple injection strategy, a load of 22 bar IMEPn is achieved with a net fuel conversion efficiency of 42.2%, an engine-out indicated specific emissions of NOx of 1.3 g/kWh, and no measurable particulate matter, while maintaining a peak cylinder pressure below 150 bar.

show abstract

Section: Introductionmentioning

confidence: 99%

High Load Compression Ignition of Wet Ethanol Using a Triple Injection Strategy

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…The application of biofuels in internal combustion engines (ICEs) is today a relevant issue as these types of engines are widely used for stationary power plants and in the transport sector. The main task for researchers today is to search for advanced combustion concepts [1][2][3] and alternative fuels to face the issues impacted by the traditional technologies [4,5].…”

Section: Introductionmentioning

confidence: 99%

Detailed Injection Strategy Analysis of a Heavy-Duty Diesel Engine Running on Rape Methyl Ester

et al. 2021

View full text Add to dashboard Cite

Using biodiesel fuel in diesel engines for heavy-duty transport is important to meet the stringent emission regulations. Biodiesel is an oxygenated fuel and its physical and chemical properties are close to diesel fuel, yet there is still a need to analyze and tune the fuel injection parameters to optimize the combustion process and emissions. A four-injections strategy was used: two pilots, one main and one post injection. A highly advanced SOI decreases the NOx and the compression work but makes the combustion process less efficient. The pilot injection fuel mass influences the combustion only at injection close to the top dead center during the compression stroke. The post injection has no influence on the compression work, only on the emissions and the indicated work. An optimal injection strategy was found to be: pilot SOI 19.2 CAD BTDC, pilot injection fuel mass 25.4%; main SOI 3.7 CAD BTDC, main injection fuel mass 67.3% mg; post SOI 2 CAD ATDC, post injection fuel mass 7.3% (the injection fuel mass is given as a percentage of the total fuel mass injected). This allows the indicated work near the base case level to be maintained, the pressure rise rate to decrease by 20% and NOx emissions to decrease by 10%, but leads to a 5% increase in PM emissions.

show abstract

“…It is therefore expected that the combined use of ethanol and water in blends, either deliberately or unintentionally, could lead to improvements in the engine combustion and emissions. Gohn et al [19] tested various hydrated ethanol blends in HCCI combustion, both naturally aspirated and boosted, and found that ethanol with 20% water could be considered the optimal ratio for advanced combustion modes. Rosa et al [20] examined the possibility to operate a diesel engine on reactivity-controlled compression ignition (RCCI) combustion, using hydrated ethanol as a low reactivity fuel.…”

Section: Introductionmentioning

confidence: 99%