Fuel Stratification and Partially Premixed Combustion With Neat N-Butanol in a Compression Ignition Engine

2017 ◽  
Author(s):  
Shouvik Dev ◽  
Tongyang Gao ◽  
Xiao Yu ◽  
Mark Ives ◽  
Ming Zheng
Keyword(s):  
Direct Injection ◽  
Pressure Rise ◽  
Premixed Combustion ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Engine Load ◽  
Fuel Stratification ◽  
Partially Premixed Combustion ◽  
Rise Rate ◽  
Partially Premixed

Homogeneous Charge Compression Ignition (HCCI) has been considered as an ideal combustion mode for compression ignition engines due to its superb thermal efficiency and low emissions of nitrogen oxides (NOx) and particulate matter (PM). However, a challenge that limits practical applications of HCCI is the lack of control over the combustion rate, which either deteriorates thermal efficiency at low engine load, or produces excessive pressure rise rate and combustion noise at high engine load. Fuel stratification and partially premixed combustion (PPC) have considerably improved the control over the heat release profile with modulations of the ratio between premixed fuel and directly injected fuel, as well as injection timing for ignition initiation. It leverages the advantages of both conventional direct injection compression ignition and HCCI. Compared with those of HCCI, the ignition ability and combustion efficiency of PPC are significantly enhanced at low engine load, and the low emissions of NOx and PM are maintained with lower pressure rise rate. In this study, neat n-butanol is employed to generate the fuel stratification and partially premixed combustion in a single cylinder compression ignition engine. A fuel such as n-butanol can provide additional benefits of even lower emissions, and can potentially lead to a reduced carbon footprint and improved energy security if produced appropriately from biomass sources. Intake port fuel injection (PFI) of neat n-butanol is used for the delivery of the premixed fuel, while the direct injection (DI) of neat n-butanol is applied to generate the fuel stratification. Effects of PFI-DI fuel ratio, DI timing, and intake pressure, on the combustion, are studied in detail. Different conditions are identified at which clean and efficient combustion can be achieved at a baseline load of 6 bar IMEP. An extended load of 14 bar IMEP is demonstrated using stratified combustion with combustion phasing control.

Fuel Stratification and Partially Premixed Combustion With Neat n-Butanol in a Compression Ignition Engine

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Shouvik Dev ◽  
Tongyang Gao ◽  
Xiao Yu ◽  
Mark Ives ◽  
Ming Zheng
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Premixed Combustion ◽  
Injection Timing ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Fuel Stratification ◽  
Partially Premixed Combustion ◽  
Partially Premixed ◽  
Ci Engines

Homogeneous charge compression ignition (HCCI) has been considered as an ideal combustion mode for compression ignition (CI) engines due to its superb thermal efficiency and low emissions of nitrogen oxides (NOx) and particulate matter. However, a challenge that limits practical applications of HCCI is the lack of control over the combustion rate. Fuel stratification and partially premixed combustion (PPC) have considerably improved the control over the heat release profile with modulations of the ratio between premixed fuel and directly injected fuel, as well as injection timing for ignition initiation. It leverages the advantages of both conventional direct injection compression ignition and HCCI. In this study, neat n-butanol is employed to generate the fuel stratification and PPC in a single cylinder CI engine. A fuel such as n-butanol can provide additional benefits of even lower emissions and can potentially lead to a reduced carbon footprint and improved energy security if produced appropriately from biomass sources. Intake port fuel injection (PFI) of neat n-butanol is used for the delivery of the premixed fuel, while the direct injection (DI) of neat n-butanol is applied to generate the fuel stratification. Effects of PFI-DI fuel ratio, DI timing, and intake pressure on the combustion are studied in detail. Different conditions are identified at which clean and efficient combustion can be achieved at a baseline load of 6 bar IMEP. An extended load of 14 bar IMEP is demonstrated using stratified combustion with combustion phasing control.

Characterization of Partially Premixed Combustion With Ethanol: EGR Sweeps, Low and Maximum Loads

2010 ◽  
Vol 132 (8) ◽  
Author(s):  
Vittorio Manente ◽  
Bengt Johansson ◽  
Pert Tunestal
Keyword(s):  
High Efficiency ◽  
Pressure Rise ◽  
Premixed Combustion ◽  
Maximum Pressure ◽  
Pressure Rise Rate ◽  
Start Of Injection ◽  
Partially Premixed Combustion ◽  
Rise Rate ◽  
Partially Premixed ◽  
Gas Recirculation

Exhaust gas recirculation (EGR) sweeps were performed on ethanol partially premixed combustion (PPC) to show different emission and efficiency trends as compared with diesel PPC. The sweeps showed that when the EGR rate is increased, the efficiency does not diminish, HC trace is flat, and CO is low even with 45% of EGR. NOx exponentially decreases by increasing EGR while soot levels are nearly zero throughout the sweep. The EGR sweeps underlined that at high EGR levels, the pressure rise rate is a concern. To overcome this problem and keep high efficiency and low emissions, a sweep in the timing of the pilot injection and pilot-main ratio was done at ∼16.5 bars gross IMEP. It was found that with a pilot-main ratio of 50:50, and by placing the pilot at −60 with 42% of EGR, NOx and soot are below EURO VI levels; the indicated efficiency is 47% and the maximum pressure rise rate is below 10 bar/CAD. Low load conditions were examined as well. It was found that by placing the start of injection at −35 top dead center, the efficiency is maximized, on the other hand, when the injection is at −25, the emissions are minimized, and the efficiency is only 1.64% lower than its optimum value. The idle test also showed that a certain amount of EGR is needed in order to minimize the pressure rise rate.

Characterization of Partially Premixed Combustion With Ethanol: EGR Sweeps, Low and Maximum Loads

2009 ◽  
Author(s):  
Vittorio Manente ◽  
Bengt Johansson ◽  
Pert Tunestal
Keyword(s):  
High Efficiency ◽  
Pressure Rise ◽  
Premixed Combustion ◽  
Maximum Pressure ◽  
Pressure Rise Rate ◽  
Partially Premixed Combustion ◽  
Rise Rate ◽  
Low Load ◽  
Partially Premixed

EGR sweeps were performed on Ethanol Partially Premixed Combustion, PPC, to show different emission and efficiency trends as compared to Diesel PPC. The sweeps showed that increasing the EGR rate the efficiency does not diminish, HC trace is flat and CO is low even with 45% of EGR. NOx exponentially decreases by increasing EGR while soot levels are nearly zero throughout the sweep. The EGR sweeps underlined that at high EGR levels, the pressure rise rate is a concern. To overcome this problem and keep high efficiency and low emissions a sweep in timing of the pilot injection and pilot-main ratio was done at ∼16.5 bar gross IMEP. It was found that with a pilot-main ratio of 50–50 and by placing the pilot at −60 with 42% of EGR, NOx and soot are below EURO VI levels, the indicated efficiency is 47% and the maximum pressure rise rate is below 10 bar/CAD. Low load conditions were examined as well. It was found that by placing the SOI at −35 TDC the efficiency is maximized on the other hand when the injection is at −25 the emissions are minimized and the efficiency is only 1.64% lower than its optimum value. The idle test also showed that a certain amount of EGR is needed in order to minimize the pressure rise rate.

Investigation on the Impact of Fuel Properties on Partially Premixed Combustion Characteristics in a Light Duty Diesel Engine

2012 ◽  
Author(s):  
Hadeel Solaka ◽  
Martin Tunér ◽  
Bengt Johansson
Keyword(s):  
Pressure Rise ◽  
Combustion Characteristics ◽  
Premixed Combustion ◽  
Unburned Hydrocarbon ◽  
Light Duty ◽  
Start Of Injection ◽  
Partially Premixed Combustion ◽  
Rise Rate ◽  
Partially Premixed ◽  
The Impact

The impact of fuel composition on the emission performance and combustion characteristics for partially premixed combustion (PPC) were examined for four fuels in the gasoline boiling range together with Swedish diesel MK1. Experiments were carried out at 8 bar IMEPg and 1500 rpm with 53±1% EGR and λ = 1.5. This relation gave inlet mole fractions of approximately 5% CO2 and 13% O2. The combustion phasing was adjusted by means of start of injection (SOI), for all fuels, over the range with stable combustion and acceptable pressure rise rate combined with maintained λ, EGR ratio, inlet pressure, and load. The operating range was limited by combustion instability for the high RON fuels, while MK1 and the low RON fuels could be operated over the whole MBT plateau. The largest difference in engine-out emissions between the fuels was the filtered smoke number (FSN), as the gasoline fuels produced a much lower FSN value than MK1. Higher RON value gave higher levels of carbon monoxide (CO) and unburned hydrocarbon (HC) for the gasoline fuels, while MK1 had the lowest levels of these emissions.

scholarly journals Study of the Combustion Process of a Homogeneous Charge Compression Ignition (HCCI) Engine and a Partially Premixed Combustion (PPC) Mode of a Compression Ignition Engine Using Natural Gas as an Alternative Fuel

2021 ◽  
Vol 84 (2) ◽  
pp. 98-115
Author(s):  
Saliha Mohammed Belkebir ◽  
Benyoucef Khelidj ◽  
Miloud Tahar-Abbes
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Combustion Process ◽  
Flow Simulation ◽  
Premixed Combustion ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Hcci Engine ◽  
Partially Premixed Combustion ◽  
Partially Premixed ◽  
Homogeneous Charge

In order to investigate a viable approach to achieving high efficiencies and low nitrogen oxide (NOX) emissions, this paper presents the application of a homogeneous charge compression ignition (HCCI) engine and the partially premixed combustion (PPC) mode applied to a heavy diesel engine. The effect of carbon dioxide (CO2) fraction on combustion parameters was analyzed and discussed in detail. For this purpose, on the one hand, ANSYS CHEMKIN-Pro software was used to perform simulations of a closed homogeneous reactor under conditions relevant to HCCI engines, and on the other hand, ANSYS-Fluent software was used by adding a CO2 fraction varying from 20% to 58% to methane fuel to study 2D flow simulation by applying a PPC combustion mode to predict the distribution of various output parameters such as in-cylinder temperature, in-cylinder pressure and emissions. In comparison with the two presented models, it was found that the HCCI engine showed a lower NOX level than the PPC mode and this was due to the lower in-cylinder temperature in the HCCI engine.

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