scholarly journals Catalytic partial oxidation reformation of diesel, gasoline, and natural gas for use in low temperature combustion engines

Fuel ◽  
2019 ◽  
Vol 246 ◽  
pp. 295-307 ◽  
Author(s):  
Deivanayagam Hariharan ◽  
Ruinan Yang ◽  
Yingcong Zhou ◽  
Brian Gainey ◽  
Sotirios Mamalis ◽  
...  
Keyword(s):  
Low Temperature ◽  
Natural Gas ◽  
Partial Oxidation ◽  
Catalytic Partial Oxidation ◽  
Low Temperature Combustion ◽  
Combustion Engines ◽  
Temperature Combustion

Investigating Fuel Condensation Processes in Low Temperature Combustion Engines

2014 ◽  
Author(s):  
Lu Qiu ◽  
Rolf D. Reitz
Keyword(s):  
Low Temperature ◽  
Combustion Engine ◽  
Phase Region ◽  
Low Temperature Combustion ◽  
Combustion Engines ◽  
Two Phase ◽  
Temperature Combustion ◽  
Real Gas Effects ◽  
Unburned Hydrocarbons ◽  
Late Stages

Condensation of gaseous fuel is investigated in a low temperature combustion engine fueled with double direct-injected diesel and premixed gasoline at two load conditions. Possible condensation is examined by considering real gas effects with the Peng-Robinson equation of state and assuming thermodynamic equilibrium of the two fuels. The simulations show that three representative condensation events are observed. The first two condensations are found in the spray some time after the two direct injections, when the evaporative cooling reduces the local temperature until phase separation occurs. The third condensation event occurs during the late stages of the expansion stroke, during which the continuous expansion sends the local fluid into the two-phase region again. Condensation was not found to greatly affect global parameters, such as the average cylinder pressure and temperature mainly because, before the main combustion event, the condensed phase was converted back to the vapor phase due to compression and/or first stage heat release. However, condensed fuel is shown to affect the emission predictions, including engine-out particulate matter and unburned hydrocarbons.

A Computational Investigation of the Impact of Multiple Injection Strategies on Combustion Efficiency in Diesel-Natural Gas Dual Fuel Low Temperature Combustion Engine

2019 ◽  
Author(s):  
Lorenzo Bartolucci ◽  
Stefano Cordiner ◽  
Vincenzo Mulone ◽  
Sundar R. Krishnan ◽  
Kalyan K. Srinivasan
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Natural Gas ◽  
Combustion Efficiency ◽  
Dual Fuel ◽  
Pilot Injection ◽  
Low Temperature Combustion ◽  
Single Cylinder ◽  
Temperature Combustion ◽  
The Impact

Abstract Dual fuel diesel-methane low temperature combustion (LTC) has been investigated by various research groups, showing high potential for emissions reduction (especially oxides of nitrogen (NOx) and particulate matter (PM)) without adversely affecting fuel conversion efficiency in comparison with conventional diesel combustion. However, when operated at low load conditions, dual fuel LTC typically exhibit poor combustion efficiencies. This behavior is mainly due to low bulk gas temperatures under lean conditions, resulting in unacceptably high carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions. A feasible and rather innovative solution may be to split the pilot injection of liquid fuel into two injection pulses, with the second pilot injection supporting the methane combustion once the process is initiated by the first one. In this work, diesel-methane dual fuel LTC is investigated numerically in a single-cylinder heavy-duty engine operating at 5 bar brake mean effective pressure (BMEP) at 85% and 75% percentage of energy substitution (PES) by methane (taken as a natural gas surrogate). A multidimensional model is first validated in comparison with experimental data obtained on the same single-cylinder engine for early single pilot diesel injection at 310 CAD and 500 bar rail pressure. With the single pilot injection case as baseline, the effects of multiple pilot injections and different rail pressures on combustion emissions are investigated, again showing good agreement with experimental data. Apparent heat release rate and cylinder pressure histories as well as combustion efficiency trends are correctly captured by the numerical model. Results prove that higher rail pressures yield reductions of HC and CO by 90% and 75%, respectively, at the expense of NOx emissions, which increase by ∼30% from baseline. Furthermore, it is shown that post-injection during the expansion stroke does not support the stable development of the combustion front as the combustion process is confined close to the diesel spray core.

Evolution, challenges and path forward for low temperature combustion engines

2017 ◽  
Vol 61 ◽  
pp. 1-56 ◽  
Author(s):  
Avinash Kumar Agarwal ◽  
Akhilendra Pratap Singh ◽  
Rakesh Kumar Maurya
Keyword(s):  
Low Temperature ◽  
Low Temperature Combustion ◽  
Combustion Engines ◽  
Temperature Combustion

scholarly journals A Computational Investigation of the Impact of Multiple Injection Strategies on Combustion Efficiency in Diesel–Natural Gas Dual-Fuel Low-Temperature Combustion Engines

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Lorenzo Bartolucci ◽  
Stefano Cordiner ◽  
Vincenzo Mulone ◽  
Sundar R. Krishnan ◽  
Kalyan K. Srinivasan
Keyword(s):  
Experimental Data ◽  
Low Temperature ◽  
Natural Gas ◽  
Combustion Efficiency ◽  
Dual Fuel ◽  
Pilot Injection ◽  
Low Temperature Combustion ◽  
Single Cylinder ◽  
Temperature Combustion ◽  
The Impact

Abstract Dual-fuel diesel–methane low-temperature combustion (LTC) has been investigated by various research groups, showing high potential for emissions reduction (especially oxides of nitrogen oxide (NOx) and particulate matter (PM)) without adversely affecting fuel conversion efficiency in comparison with conventional diesel combustion. However, when operated at low load conditions, dual-fuel LTC typically exhibits poor combustion efficiencies. This behavior is mainly due to low bulk gas temperatures under lean conditions, resulting in unacceptably high carbon monoxide (CO) and unburned hydrocarbon (UHC) emissions. A feasible and rather innovative solution may be to split the pilot injection of liquid fuel into two injection pulses, with the second pilot injection supporting CO and UHC oxidation once combustion is initiated by the first one. In this study, diesel–methane dual-fuel LTC is investigated numerically in a single-cylinder heavy-duty engine operating at 5 bar brake mean effective pressure (BMEP) at 85% and 75% percentage of energy substitution (PES) by methane (taken as a natural gas (NG) surrogate). A multidimensional model is first validated in comparison with the experimental data obtained on the same single-cylinder engine for early single pilot diesel injection at 310 crank angle degrees (CAD) and 500 bar rail pressure. With the single pilot injection case as baseline, the effects of multiple pilot injections and different rail pressures on combustion and emissions are investigated, again showing good agreement with the experimental data. Apparent heat release rate and cylinder pressure histories as well as combustion efficiency trends are correctly captured by the numerical model. Results prove that higher rail pressures yield reductions of HC and CO by 90% and 75%, respectively, at the expense of NOx emissions, which increase by ∼30% from baseline still remaining at very low level (under 1 g/kWh). Furthermore, it is shown that postinjection during the expansion stroke does not support the stable development of the combustion front as the combustion process is confined close to the diesel spray core.

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