An Investigation on the Performance of an Oxidation Catalyst Using Two-dimensional Simulation with Detailed Reaction Mechanism

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sreeharsh Nair ◽  
Mayank Mittal
Keyword(s):  
Single Channel ◽  
Catalytic Converter ◽  
Oxidation Catalyst ◽  
Low Temperature Combustion ◽  
Wide Range ◽  
Detailed Reaction Mechanism ◽  
Temperature Combustion ◽  
High Concentrations ◽  
Dimensional Simulation ◽  
Surface Reaction Kinetics

AbstractThe advent of stricter emission standards has increased the importance of aftertreatment devices and the role of numerical simulations in the evolution of better catalytic converters in order to satisfy these emission regulations. In this paper, a 2-D numerical simulation of a single channel of the monolith catalytic converter is presented by using detailed surface reaction kinetics aiming to investigate the chemical behaviour inside the converter. The model has been developed to study the conversion of carbon monoxide (CO) in the presence of propene (C3H6) for low-temperature combustion (LTC) engine application. The inhibition effect of C3H6 over a wide range of CO inlet concentrations is investigated. Considering both low and high levels of CO concentration at the inlet, the 2-D model predicted better results than their corresponding 1-D counterparts when compared with the experimental data from literature. It was also observed that C3H6 inhibition at high temperatures was significant, particularly for high concentrations of CO compared to low concentrations of CO at the inlet.

Enhancing Low-Temperature Combustion With Biodiesel Blending in a Diesel Engine at a Medium Load Condition

2015 ◽  
Vol 138 (4) ◽  
Author(s):  
Sunyoup Lee ◽  
Seungmook Oh ◽  
Junghwan Kim ◽  
Duksang Kim
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Oxygen Concentration ◽  
Load Condition ◽  
Low Temperature Combustion ◽  
Effective Pressure ◽  
Oxygen Level ◽  
Indicated Mean Effective Pressure ◽  
Wide Range ◽  
Temperature Combustion

The present study investigated the effects of biodiesel blending under a wide range of intake oxygen concentration levels in a diesel engine. This study attempted to identify the lowest biodiesel blending rate that achieves acceptable levels of nitric oxides (NOx), soot, and coefficient of variation in the indicated mean effective pressure (COVIMEP). Biodiesel blending was to be minimized in order to reduce the fuel penalty associated with the biodiesels lower caloric value (LCV). Engine experiments were performed in a 1 l single-cylinder diesel engine at an engine speed of 1400 rev/min under a medium load condition. The blend rate and intake oxygen concentration were varied independently of each other at a constant intake pressure of 200 kPa. The biodiesel blend rate varied from 0% (B000) to 100% biodiesel (B100) at a 20% increment. The intake oxygen level was adjusted from 8% to 19% by volume (vol. %) in order to embrace both conventional and low-temperature combustion (LTC) operations. A fixed injection duration of 788 ms at a fuel rail pressure of 160 MPa exhibited a gross indicated mean effective pressure (IMEP) between 750 kPa and 910 kPa, depending on the intake oxygen concentration. The experimental results indicated that the intake oxygen level had to be below 10 vol. % to achieve the indicated specific NOx (ISNOx) below 0.2 g/kW h with the B000 fuel. However, a substantial soot increase was exhibited at such a low intake oxygen level. Biodiesel blending reduced NOx until the blending rate reached 60% with reduced in-cylinder temperature due to lower total energy release. As a result, 60% biodiesel-blended diesel (B060) achieved NOx, soot, and COVIMEP of 0.2 g/kW h, 0.37 filter smoke number (FSN), and 0.5, respectively, at an intake oxygen concentration of 14 vol. %. The corresponding indicated thermal efficiency was 43.2%.

Investigation of Hydrogen Emissions in Partially Premixed Diesel Combustion

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
William F. Northrop ◽  
Lucas M. Vanderpool ◽  
Praveen V. Madathil ◽  
Dennis N. Assanis ◽  
Stanislav V. Bohac
Keyword(s):  
Equilibrium Constant ◽  
Constant Load ◽  
Low Temperature Combustion ◽  
Spark Ignition Engines ◽  
Diesel Fuels ◽  
Wide Range ◽  
Temperature Combustion ◽  
Partially Premixed ◽  
Premixed Low Temperature Combustion ◽  
Low Sulfur

Partially premixed combustion strategies offer many advantages for compression ignition engines. One such advantage for those operating on diesel fuels is the simultaneous reduction in soot and NOx achievable over a wide range of equivalence ratios. Though often not measured in engine experiments, gaseous H2 is a byproduct of incomplete combustion and can be useful for the regeneration of aftertreatment devices. Correlations for the exhaust concentration of H2, mostly derived from experiments with homogeneous spark ignition engines, indicate that it is emitted either in proportion to CO directly or as a function of a pseudowater gas shift equilibrium constant. In this work, H2 is measured over a range of equivalence ratios in a multicylinder diesel engine operating in a partially premixed low temperature combustion (LTC) mode using both low sulfur diesel fuel and soy-based biodiesel. Biodiesel was found to have the same bulk gas emissions of major species including H2 over the range of equivalence ratio in LTC for a constant load and combustion phasing. It also was found that the experimental H2 concentration was near the value predicted by the equilibrium constant for equivalence ratios greater that 0.85 but was increasingly lower for leaner points.

Investigation of Hydrogen Emissions in Partially Premixed Diesel Combustion

2009 ◽  
Author(s):  
William F. Northrop ◽  
Lucas M. Vanderpool ◽  
Praveen V. Madathil ◽  
Dennis N. Assanis ◽  
Stanislav V. Bohac
Keyword(s):  
Equilibrium Constant ◽  
Constant Load ◽  
Low Temperature Combustion ◽  
Spark Ignition Engines ◽  
Diesel Fuels ◽  
Wide Range ◽  
Temperature Combustion ◽  
Partially Premixed ◽  
Premixed Low Temperature Combustion ◽  
Low Sulfur

Partially premixed combustion strategies offer many advantages for compression ignition engines. One such advantage for engines operating on diesel fuels is the simultaneous reduction of soot and NOX achievable over a wide range of equivalence ratios. Though often not measured in engine experiments, gaseous H2 is a byproduct of incomplete combustion and can be useful for the regeneration of aftertreatment devices. Correlations for the exhaust concentration of H2, mostly derived from experiments with homogeneous spark ignition engines, indicate that it is emitted either in proportion to CO directly or as a function of a pseudo-water gas shift equilibrium constant. In this work, H2 is measured over a range of equivalence ratios in a multi-cylinder diesel engine operating in a partially premixed low temperature combustion (LTC) mode using both low sulfur diesel fuel and soy-based biodiesel. Biodiesel was found to have the same bulk gas emissions of major species including H2 over the range of equivalence ratio in LTC for a constant load and combustion phasing. It also was found that the experimental H2 concentration was near the value predicted by the equilibrium constant for equivalence ratios greater that 0.9 but was increasingly lower for leaner points.

An Investigation of the Low Temperature Combustion Regime (LTC) in a Small Bore HSDI Diesel Engine

2005 ◽  
Author(s):  
Jasmeet Singh ◽  
Yusuf Poonawala ◽  
Inderpal Singh ◽  
Naeim A. Henein ◽  
Walter Bryzik
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Fuel Economy ◽  
Combustion Regime ◽  
Injection System ◽  
Fuel Vapor ◽  
Low Temperature Combustion ◽  
Wide Range ◽  
Temperature Combustion ◽  
Hsdi Diesel Engine

The low temperature combustion regime (LTC) has been known to simultaneously reduce both NOx and smoke emissions. The concept is to burn the fuel vapor-air charge, low in oxygen concentration, at low temperatures to reduce the formation of both NOx and smoke emissions. The paper investigates two combustion concepts in the LTC regime, the MK (modulated kinetics) and the smokeless locally rich diesel combustion and proposes a new strategy for a further reduction in emissions with minimum penalty in fuel economy. Tests were carried out under simulated turbo charged conditions on a single cylinder, small bore HSDI diesel engine with a re-entrant bowl combustion chamber. The engine is equipped with a common rail fuel injection system. Tests covered a wide range of injection pressures, EGR rates, injection timings and swirl ratios to determine their individual and collective contributions in engine-out emissions and fuel economy within this combustion regime. The proposed strategy is based on the results of this experimental investigation.

Regulated emissions and speciated hydrocarbons from smokeless low-temperature combustion diesel engines with ultra-high exhaust gas recirculation and exhaust oxidation catalyst

2009 ◽  
Vol 223 (5) ◽  
pp. 673-683 ◽  
Author(s):  
T Li ◽  
H Ogawa
Keyword(s):  
Low Temperature ◽  
Exhaust Gas Recirculation ◽  
Combustion Regime ◽  
Oxidation Catalyst ◽  
Exhaust Gas ◽  
Low Temperature Combustion ◽  
Toxic Emissions ◽  
Temperature Combustion ◽  
Clean Diesel Combustion ◽  
Gas Recirculation

With ultra-high exhaust gas recirculation (EGR) suppressing the in-cylinder soot and nitrogen oxides (NO x) formation as well as with the exhaust oxidation catalyst removing the engine-out total unburned hydrocarbon (THC) and carbon monoxide (CO) emissions, clean diesel combustion in terms of low regulated emissions (NO x, particulate matter, THC, and CO) can be established in an operating range up to 50 per cent load. However, unregulated emissions such as aldehydes, aromatics, and 1,3-butadiene, which are seen as a severe threat to human health, are concerned when operating the engine with ultra-high EGR. In this study, the THC emissions from a diesel engine operated with ultra-high EGR low-temperature combustion were speciated using Fourier transform infrared spectroscopy. Some unregulated toxic emissions including aldehydes, aromatics, 1,3-butadiene, and some low molecular hydrocarbons dramatically increase in the ultra-high EGR low-temperature combustion regime. The exhaust oxidation catalyst is effective to remove aldehydes and some unsaturated hydrocarbons, but aromatics and methane generated from the ultra-high EGR operation are hardly reduced, particularly at higher loads.

Enhancing Low Temperature Combustion With Biodiesel Blending in a Diesel Engine at a Medium Load Condition

2014 ◽  
Author(s):  
Sunyoup Lee ◽  
Seungmook Oh ◽  
Junghwan Kim ◽  
Duksang Kim
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Oxygen Concentration ◽  
Load Condition ◽  
Low Temperature Combustion ◽  
Effective Pressure ◽  
Oxygen Level ◽  
Indicated Mean Effective Pressure ◽  
Wide Range ◽  
Temperature Combustion

The present study investigated the effects of biodiesel blending under a wide range of intake oxygen concentration levels in a diesel engine. This study attempted to identify the lowest biodiesel blending rate that achieves acceptable levels of nitric oxides (NOx), soot, and coefficient of variation in the indicated mean effective pressure (COVIMEP). Biodiesel blending was to be minimized in order to reduce the fuel penalty associated with the biodiesels lower caloric value. Engine experiments were performed in a 1-liter single-cylinder diesel engine at an engine speed of 1400 rev/min under a medium load condition. The blend rate and intake oxygen concentration were varied independently of each other at a constant intake pressure of 200 kPa. The biodiesel blend rate varied from 0% (B000) to 100% biodiesel (B100) at a 20% increment. The intake oxygen level was adjusted from 8 to 19% by volume (vol %) in order to embrace both conventional and low-temperature combustion (LTC) operations. A fixed injection duration of 788 μs at a fuel rail pressure of 160 MPa exhibited a gross indicated mean effective pressure (IMEP) between 750 kPa and 910 kPa, depending on the intake oxygen concentration. The experimental results indicated that the intake oxygen level had to be below 10 vol% to achieve the indicated specific NOx (ISNOx) below 0.2g/kWhr with the B000 fuel. However, a substantial soot increase was exhibited at such a low intake oxygen level. Biodiesel blending reduced NOx until the blending rate reached 60% with reduced in-cylinder temperature due to lower total energy release. As a result, 60%-biodiesel blended diesel (B060) achieved NOx, soot, and COVIMEP of 0.2 g/kWhr, 0.37 filter smoke number (FSN), and 0.5, respectively, at an intake oxygen concentration of 14 vol%. The corresponding indicated thermal efficiency was 43.2%.

Speciation Analysis of Light Hydrocarbons and Hydrogen Production During Diesel Low Temperature Combustion

2011 ◽  
Author(s):  
Usman Asad ◽  
Arturo Mendoza ◽  
Kelvin Xie ◽  
Marko Jeftic ◽  
Meiping Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Hydrogen Production ◽  
Oxidation Catalyst ◽  
Individual Species ◽  
Hydrocarbon Emissions ◽  
Exhaust Aftertreatment ◽  
Boost Pressure ◽  
Single Shot ◽  
Low Temperature Combustion ◽  
Temperature Combustion

The simultaneous reduction in engine-out NOx and soot emissions with diesel low temperature combustion (LTC) is generally accompanied by high levels of hydrocarbon (THC) and carbon monoxide (CO) emissions in the exhaust. To achieve clean diesel combustion in terms of low regulated emissions (NOx, soot, THC, and CO), the exhaust combustibles must be dealt with the exhaust aftertreatment (typically a diesel oxidation catalyst). In this work, engine tests were performed to realize LTC on a single-cylinder common-rail diesel engine up to 12 bar IMEP. A single-shot fuel injection strategy was employed to push the diesel cycles into LTC with exhaust gas recirculation (EGR). The combustibles in the exhaust were generally found to increase with the LTC load and were observed to be a function of the overall equivalence ratio. A Fourier transform infrared (FTIR) spectroscopy analysis of light hydrocarbon emissions found methane to constitute a significant component of the hydrocarbon emissions under the tested LTC conditions. The relative fraction of individual species in the hydrocarbons also changed, indicating a richer combustion zone and a reduction in engine-out THC reactivity. The hydrogen production was found to correlate consistently with the CO emissions, largely independent of the boost pressure or engine load under the tested LTC conditions. This research intends to identify the major constituents of the THC emissions and highlight the possible impact on exhaust aftertreatment.

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