Strategies for Reduced Unburned Hydrocarbon and Carbon Monoxide Emissions in Diesel Propane Dual Fuel Low Temperature Combustion

Strategies for Reduced Unburned Hydrocarbon and Carbon Monoxide Emissions in Diesel Propane Dual Fuel Low Temperature Combustion PDF Author: Kyle Anthony Hodges
Publisher:
ISBN:
Category :
Languages : en
Pages : 142

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Book Description
The present manuscript discusses the use of two diesel injections in diesel-ignited propane dual fuel Low Temperature Combustion (LTC). Using propane fumigation into the intake runners of a single cylinder research engine, the maximum and minimum percent energy substitution (PES) values were obtained to be 90% and 53%, respectively at 3.3 bar BMEP. An optimal PES value of 80% was used to explore the effects of a secondary injection on the engine-out emissions. The secondary injection proved to have a strong influence on combustion phasing (CA50). As combustion is phased closer to TDC the IFCE shows and increase of 4% at 5 bar BMEP and 6% at 3.3 bar BMEP. Finally, a relationship between the IFCE and the CO to CO2 conversion was developed. An increase in the carbon to hydrogen ratio of the fuel shows a reduction of the CO output of the engine while the CO2 concentration increases. More importantly however, the CO to CO2 conversion shows a direct effect on the IFCE. It is shown that a decrease in CO emissions found in the engine-out emissions will correlate directly with an increase in the IFCE.

Strategies for Reduced Unburned Hydrocarbon and Carbon Monoxide Emissions in Diesel Propane Dual Fuel Low Temperature Combustion

Strategies for Reduced Unburned Hydrocarbon and Carbon Monoxide Emissions in Diesel Propane Dual Fuel Low Temperature Combustion PDF Author: Kyle Anthony Hodges
Publisher:
ISBN:
Category :
Languages : en
Pages : 142

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Book Description
The present manuscript discusses the use of two diesel injections in diesel-ignited propane dual fuel Low Temperature Combustion (LTC). Using propane fumigation into the intake runners of a single cylinder research engine, the maximum and minimum percent energy substitution (PES) values were obtained to be 90% and 53%, respectively at 3.3 bar BMEP. An optimal PES value of 80% was used to explore the effects of a secondary injection on the engine-out emissions. The secondary injection proved to have a strong influence on combustion phasing (CA50). As combustion is phased closer to TDC the IFCE shows and increase of 4% at 5 bar BMEP and 6% at 3.3 bar BMEP. Finally, a relationship between the IFCE and the CO to CO2 conversion was developed. An increase in the carbon to hydrogen ratio of the fuel shows a reduction of the CO output of the engine while the CO2 concentration increases. More importantly however, the CO to CO2 conversion shows a direct effect on the IFCE. It is shown that a decrease in CO emissions found in the engine-out emissions will correlate directly with an increase in the IFCE.

Exploration of High Efficiency Pathways in Dual Fuel Low Temperature Combustion Engines

Exploration of High Efficiency Pathways in Dual Fuel Low Temperature Combustion Engines PDF Author: Prabhat Ranjan Jha
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 313

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It's crucial to use advanced combustion strategies to increase efficiency and decrease engine-out pollutants because of the compelling need to reduce the global carbon footprint. This dissertation proposes dual fuel low-temperature combustion as a viable strategy to decrease engine-out emissions and increase the thermal efficiency of future heavy-duty internal combustion (IC) engines. In dual fuel combustion, a low reactivity fuel (e.g. methane, propane) is ignited by a high reactivity fuel (diesel) in a compression-ignited engine. Generally, the energy fraction of low reactivity fuel is maintained at much higher levels than the energy fraction of the high reactivity fuel. For a properly calibrated engine, combustion occurs at lean and low-temperature conditions (LTC). This decreases the chances of the formation of soot and oxides of nitrogen within the engine. However, at low load conditions, this type of combustion results in high hydrocarbon and carbon monoxide emissions. The first part of this research 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 (SCRE). Gaseous methane fumigated into the intake manifold at various methane energy fractions was ignited using a high-pressure diesel pilot injection at 310 CAD. Cyclic combustion variations at both loads were also analyzed to obtain further insights into the combustion process and identify opportunities to further improve fuel conversion efficiencies at low load operation. In the second part, the cyclic variations in dual fuel combustion of three different low reactivity fuels (methane, propane, and gasoline) ignited using a high-pressure diesel pilot injection was examined and the challenges and opportunities in utilizing methane, propane, and gasoline in diesel ignited dual fuel combustion, as well as strategies for mitigating cyclic variations, were explored. Finally, in the third part a CFD model was created for diesel methane dual fuel LTC. The validated model was used to investigate the effect of methane on diesel autoignition and various spray targeting strategies were explored to mitigate high hydrocarbon and carbon monoxide emissions at low load conditions.

Pathways for Low Emissions Utilizing Spray Targeted Reactivity Stratification (STARS) in High Efficiency Natural Gas Dual Fuel Combustion

Pathways for Low Emissions Utilizing Spray Targeted Reactivity Stratification (STARS) in High Efficiency Natural Gas Dual Fuel Combustion PDF Author: James S Harris
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 0

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Book Description
Internal combustion engines are a key aspect of society, and their continued use poses challenges from an environmental standpoint since they emit pollutant and greenhouse gas emissions. This dissertation focuses on experimental analysis of dual-fuel low temperature combustion (LTC), which can be used as a strategy to reduce engine-out emissions and increase engine efficiencies. Dual fuel LTC uses two different fuels, a high reactivity fuel (HRF) and a low reactivity fuel (LRF). The HRF has a higher cetane number than the LRF, which allows for easier auto-ignition in compression ignition engines. Dual fuel engines also utilize high air to fuel ratios to achieve LTC. This, combined with early injection timings of the HRF, helps to reduce oxides of nitrogen (NOx) emissions. At low load conditions, this is a problem since higher cycle-to-cycle variations can increase pollutants such as unburned hydrocarbons (UHC) and carbon monoxide (CO). To combat this, a firm understanding of dual fuel LTC is required, as well as a strategy for reducing the cycle-to-cycle variations. The first part of this work further identifies a combustion heat release 'transformation region' across different HRF injection timings wherein in-cylinder conditions arise that are conducive for ultra-low NOx emissions. This phenomenon occurs for different IC engine platforms and different fueling combinations. An experimental analysis, 0D chemical kinetic analysis, and 3D computation fluid dynamic (CFD) analysis were combined to elucidate the underlying causes for this phenomenon. The local stratification level of the fuel/air mixture was identified as the likely cause of combustion heat release transformation with changing HRF injection timing. The second part of the present work builds upon the findings of the first part by utilizing local stratification to mitigate cycle-to-cycle variations that are present at low loads. A framework of experiments was formulated for both a low engine load of 5 bar gross indicated mean effective pressure (IMEPg) and a high load of 15 bar IMEPg, wherein an injection strategy concept termed Spray TArgeted Reactivity Stratification (STARS) was utilized using both diesel and Polyoxymethelene-dimethyl-ether (POMDME) as HRFs. A steep decrease in UHC and CO emissions (> 80% reductions) as well as improved engine operation stability were demonstrated using both HRFs with dual fuel LTC at 5 bar IMEPg. Further, potential for emissions mitigation and efficiency improvement are discussed, as well as differences in the experimental results shown between the differing HRFs.

Emissions Optimization of Propane Dual Fuel Combustion Ignited by Diesel and Polyoxymethylene Dimethyl Ether At Low Loads

Emissions Optimization of Propane Dual Fuel Combustion Ignited by Diesel and Polyoxymethylene Dimethyl Ether At Low Loads PDF Author: Prabhat R Jha
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 0

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Book Description
Dual fuel engines utilize two different fuels consisting of a high reactivity fuel (HRF)injected into the cylinder and a low reactivity fuel (LRF), typically fumigated into the intakemanifold. In order to reduce the emissions of nitrogen oxides when compared against dieselcombustion, dual fuel engines begin the injection process early in the combustion cycle.However, at early injection timings dual fuel engines exhibit high emissions of both unburnedhydrocarbons (HC) and carbon monoxide (CO). This work discusses the emissions optimizationprocess to reduce emissions for two different fueling types, diesel-propane and poly-oxymethylene dimethyl ether (POMDME)-propane, on a single cylinder research engine (SCRE)based upon a PACCAR MX-11 heavy-duty engine while maintaining combustion and fuelconversion efficiencies.The parameters swept during this optimization process include start of injection, percentenergy substitution, a second injection and its timing, the split ratio - or the ratio of commandedduration of the first injection to that of the second, a coupled injection sweep, rail pressure, andintake pressure. These parameters were varied at a fixed gross indicated mean effective pressure(IMEPg) of 5 bar to represent low load operation as well as a fixed engine speed of 1339 rpm("B speed" of the SCRE). During all experiments a global limit of 1 g/kWh was set on theindicated specific NOx emissions, as well as a maximum pressure rise rate of 10 bar/deg, and acoefficient of variation of IMEPg at or below 5%. Using these limits and the emissions tradeoffsbetween HC, CO and NOx, this work was able to demonstrate diesel-propane emissionsimprovements of HC and CO of 86.4% and 66.8% respectively when compared to the baseline, while POMDME-propane emissions showed improvements in HC and CO of 90.9% and 86.2%respectively. Additionally, POMDME emissions demonstrated zero measurable filter smokenumber during all engine operations. A preliminary life cycle analysis of using both dual fuelcombinations have been compared against traditional diesel operation as well as battery poweredoperation and is found within the appendix of this work.

Strategies for Reducing Hydrocarbon Emissions in Diesel Low Temperature Combustion

Strategies for Reducing Hydrocarbon Emissions in Diesel Low Temperature Combustion PDF Author: Oluwasujibomi Sogbesan
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Natural Gas Engines

Natural Gas Engines PDF Author: Kalyan Kumar Srinivasan
Publisher: Springer
ISBN: 9811333076
Category : Technology & Engineering
Languages : en
Pages : 419

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Book Description
This book covers the various advanced reciprocating combustion engine technologies that utilize natural gas and alternative fuels for transportation and power generation applications. It is divided into three major sections consisting of both fundamental and applied technologies to identify (but not limited to) clean, high-efficiency opportunities with natural gas fueling that have been developed through experimental protocols, numerical and high-performance computational simulations, and zero-dimensional, multizone combustion simulations. Particular emphasis is placed on statutes to monitor fine particulate emissions from tailpipe of engines operating on natural gas and alternative fuels.

Modifying Diesel Engine Operating Parameters to Reduce Emissions

Modifying Diesel Engine Operating Parameters to Reduce Emissions PDF Author: W. F. Marshall
Publisher:
ISBN:
Category : Air
Languages : en
Pages : 22

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Investigation Into the Emissions and Efficiency of Low Temperature Diesel Combustion

Investigation Into the Emissions and Efficiency of Low Temperature Diesel Combustion PDF Author: Bryan M. Knight
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
As global focus shifts towards the health and conservation of the planet, greater importance is placed upon the hazardous emissions of our fossil fuels, as well as their finite supply. These two areas remain intense topics of research in order to reduce green house gas emissions and increase the fuel efficiency of our vehicles. A particular solution to this problem is the diesel engine, with its inherently fuel-lean combustion, which gives rise to low CO2 production and higher efficiencies than its gasoline counterpart. Diesel engines, however, typically exhibit higher nitrogen oxides (NOx [NOx equal NO plus NO2, where NO is nitric oxide and NO2 is nitrogen dioxide]) and soot. There exists the possibility to simultaneously reduce both emissions with the application of low temperature diesel combustion (LTC). While exhibiting great characteristics in simultaneous reductions in nitrogen oxides and soot, LTC faces challenges with higher carbon monoxide (CO) and hydrocarbon (HC) emissions, as well as penalties in fuel efficiency. The following study examines the characteristics of LTC which contribute to the differences in emissions and efficiency compared to typical conventional diesel combustion. More specifically, key engine parameters which are used to enable LTC, such as EGR and fuel pressure are swept through a full range to determine their effects on each combustion regime. Analysis will focus on comparing both combustion regimes to determine how exhaust gas recirculation (EGR) and fuel pressure relate to lowering NO and smoke concentrations, and how these relate to a penalty in fuel efficiency. This study finds that the application of LTC is able to realize a 99 percent reduction in NO while simultaneously reducing smoke by 17 percent compared to the conventional combustion counterpart. Through a sweep increasing EGR, LTC is able to defeat the typical soot-- NO tradeoff; however, brake fuel conversion efficiency decreases 6.8 percent for LTC, while conventional combustion realizes a 4 percent increase in efficiency. The sweep of increasing fuel pressure confirms typical increases in NO and decreases in smoke for both LTC and conventional combustion; however, brake fuel conversion efficiency increases 2.3 percent for LTC and drops 4 percent for conventional combustion.

Advances in Compression Ignition Natural Gas – Diesel Dual Fuel Engines

Advances in Compression Ignition Natural Gas – Diesel Dual Fuel Engines PDF Author: Hongsheng Guo
Publisher: Frontiers Media SA
ISBN: 2889666212
Category : Technology & Engineering
Languages : en
Pages : 125

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Investigation of Two Low Emissions Strategies for Diesel Engines

Investigation of Two Low Emissions Strategies for Diesel Engines PDF Author: Sang-Suk Lee
Publisher:
ISBN:
Category :
Languages : en
Pages : 256

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