scholarly journals Soot Emission Reduction in a Biogas-DME Hybrid Dual-Fuel Engine

2020 ◽  
Vol 10 (10) ◽  
pp. 3416
Author(s):  
Bui Van Ga ◽  
Pham Quoc Thai
Keyword(s):  
Equivalence Ratio ◽  
Volume Fraction ◽  
Soot Volume Fraction ◽  
Pollutant Emissions ◽  
Dual Fuel ◽  
Soot Emission ◽  
Combustion Mode ◽  
Operating Condition ◽  
Diesel Injection ◽  
Combustion Properties

Combustion characteristics and harmful emissions with emphasized soot emission in the new concept of a biogas-dimethyl ether (DME) hybrid dual-fuel engine were analyzed. The effects of DME content, biogas compositions and diesel injection were examined. At any biogas composition, a rise in DME content in the fuel mixture leads to an increase in indicative engine cycle work (Wi) and NOx but a decrease in CO and soot volume fraction (fv). The effects of DME on Wi and soot volume fraction are more significant for poor biogas than for rich biogas, contrary to its effect tendency on CO and NOx concentrations. With a given operating condition and DME content, the biogas compositions slightly affect the performance and emission of a biogas-DME hybrid dual-fuel engine. At a fixed global equivalence ratio, the reduction of diesel injection leads to an increase in Wi and NOx concentration but a decrease in CO and soot volume fraction. The lower the diesel injection is, the more significant the effects of DME content on the combustion properties and pollutant emissions are. At a given operating condition and the same global equivalence ratio, the biogas-DME PCCI combustion mode is more advantageous than biogas-DME dual-fuel combustion mode. The substitution of diesel pilot ignition by DME pilot ignition in a biogas-DME hybrid dual engine is the optimal solution for both performance improvement and pollution emissions reduction.

Laminar Flame Characteristics of Partially Premixed Palm Methyl Ester Gas Flames

2013 ◽  
Author(s):  
Diego Romero ◽  
Ramkumar N. Parthasarathy ◽  
Subramanyam R. Gollahalli
Keyword(s):  
Methyl Ester ◽  
Flow Rate ◽  
Equivalence Ratio ◽  
Volume Fraction ◽  
Laminar Flame ◽  
Soot Volume Fraction ◽  
Fuel Flow ◽  
Combustion Properties ◽  
Emission Index ◽  
Palm Methyl Ester

Palm methyl ester (PME) is a renewable biofuel that is produced by the transesterification of palm oil; it is a popular alternative fuel used in the transportation sector. The objective of this investigation was to study the combustion characteristics of flames of pre-vaporized diesel and PME in a laminar flame environment at initial equivalence ratios of 2, 3 and 7 and to isolate the factors attributable to chemical structure of the fuel. The equivalence ratio was changed by altering the fuel flow rate, while maintaining the air flow rate constant. The global CO emission index of the PME flames was significantly lower than that of the diesel flames; however, the global NO emission index was comparable. The radiative fraction of heat release and the soot volume fraction were lower for the PME flames compared to the diesel flames. The peak temperatures were comparable at an equivalence ratio of 2, but at higher equivalence ratios, the peak temperatures in the PME flames were higher. The measurements highlight the differences in the combustion properties of biofuels and petroleum fuels and the coupling effects of equivalence ratio.

Laminar Flame Characteristics of Partially Premixed Prevaporized Palm Methyl Ester and Diesel Flames

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
D. Romero ◽  
R. N. Parthasarathy ◽  
S. R. Gollahalli
Keyword(s):  
Methyl Ester ◽  
Flow Rate ◽  
Equivalence Ratio ◽  
Volume Fraction ◽  
Laminar Flame ◽  
Soot Volume Fraction ◽  
Fuel Flow ◽  
Combustion Properties ◽  
Emission Index ◽  
Palm Methyl Ester

Palm methyl ester (PME) is a renewable biofuel that is produced by the transesterification of palm oil and is a popular alternative fuel used in the transportation sector, particularly in Asia. The objective of this investigation was to study the combustion characteristics of flames of prevaporized number 2 diesel and PME in a laminar flame environment at initial equivalence ratios of 2, 3, and 7 and to isolate the factors attributable to chemical structure of the fuel. The equivalence ratio was changed by altering the fuel flow rate, while maintaining the air flow rate constant. The global CO emission index of the PME flames was significantly lower than that of the diesel flames; however, the global NO emission index was comparable. The radiative fraction of heat release and the soot volume fraction were lower for the PME flames compared to those in the diesel flames. The peak temperatures were comparable in both flames at an equivalence ratio of 2, but at higher equivalence ratios, the peak temperatures in the PME flames were higher. The measurements highlight the differences in the combustion properties of biofuels and petroleum fuels and the coupling effects of equivalence ratio.

Soot and PAH Formation Characteristics in a Micro Flow Reactor With a Controlled Temperature Profile

2011 ◽  
Author(s):  
Ryu Tanimoto ◽  
Takuya Tezuka ◽  
Susumu Hasegawa ◽  
Hisashi Nakamura ◽  
Kaoru Maruta
Keyword(s):  
Flow Velocity ◽  
Temperature Profile ◽  
Mole Fraction ◽  
Equivalence Ratio ◽  
Flow Reactor ◽  
Volume Fraction ◽  
Soot Formation ◽  
Soot Volume Fraction ◽  
Low Flow ◽  
Micro Flow

To examine soot and PAH formation processes for rich methane/air and acetylene/air mixtures, a micro flow reactor with a controlled temperature profile was employed. In the experiment for a methane/air mixture, four kinds of responses to the variations of flow velocity and equivalence ratio were observed as follows: soot formation without a flame; a flame with soot formation; a flame without soot formation; and neither flame nor soot formation. Soot formations were observed in low flow velocity and high equivalence ratio. Starting point of soot formation shifted to the upstream side, i.e., low-temperature side, of the micro flow reactor with the decrease of flow velocity. One-dimensional steady-state computation was conducted by a flame code. In high flow velocity, low mole fraction of C2H2 and high mole fraction of OH were observed in the whole region of the micro flow reactor. Soot volume fraction did not increase in this case. On the other hand, in low flow velocity, high mole fraction of C2H2 and low mole fraction of OH were observed at the downstream side of the micro flow reactor. Soot volume fraction increased in this case. Since significant soot formation was observed at the low flow velocity and the high equivalence ratio, experiments with gas sampling were conducted for acetylene/air mixture to investigate temperature and equivalence ratio dependence of soot precursor production in such condition. Volume fractions of benzene increased with an increase of temperature. They were larger at higher equivalence ratio at the same temperature. Volume fractions of styrene increased with an increase of temperature. They were larger at higher equivalence ratio when the temperature is less than 1000 K. However the tendency was changed at 1000 K, styrene volume fraction at equivalence ratio of 7.0 was larger than that at equivalence ratio of 8.0.

Laminar Partially Premixed Flames of Blends of Pre-Vaporized Jet-A Fuel and Palm Methyl Ester

2014 ◽  
Author(s):  
Arun Balakrishnan ◽  
Ramkumar N. Parthasarathy ◽  
Subramanyam R. Gollahalli
Keyword(s):  
Methyl Ester ◽  
Flow Rate ◽  
Volume Fraction ◽  
Air Flow ◽  
Soot Volume Fraction ◽  
Flame Length ◽  
Phase Reaction ◽  
Combustion Properties ◽  
Partially Premixed ◽  
Palm Methyl Ester

Biofuels, such as palm methyl ester (PME), are attractive alternates to petroleum fuels. In order to isolate the effects of fuel chemistry on the combustion properties, laminar partially premixed pre-vaporized flames of blends of Jet-A and PME (volume concentrations of 25%, 50%, 75% PME) were studied. A stainless steel circular tube (ID of 9.5 mm) served as the burner. The liquid fuel was supplied with a syringe pump into a high temperature (390°C) air flow to vaporize it completely without coking. The fuel flow rate was maintained constant and the air flow rate adjusted to obtain burner-exit equivalence ratios of 2, 3 and 7. The global flame properties including flame length, CO and NO emission indices, radiative heat fraction and in-flame properties including gas concentration (CO, CO2, NO, O2), temperature and soot volume fraction were measured. The near-burner homogeneous gas-phase reaction zone increased in length with the addition of PME at all equivalence ratios. The concentration and global emission measurements highlight the non-monotonic variation of properties with the volume concentration of PME in the fuel. The fuel-bound oxygen of PME affected the combustion properties significantly.

scholarly journals Soot Emission Analysis in Combustion of Biogas Diesel Dual Fuel Engine

2017 ◽  
Vol 2 (1) ◽  
pp. 67 ◽  
Author(s):  
Bui Van Ga ◽  
Bui Thi Minh Tu
Keyword(s):  
Equivalence Ratio ◽  
Engine Speed ◽  
Soot Formation ◽  
Dual Fuel ◽  
Diffusion Combustion ◽  
Exhaust Gas ◽  
Soot Emission ◽  
Soot Concentration ◽  
Emission Analysis ◽  
Peak Value

Soot emission in bio-gas diesel dual fuel engine has been analyzed by numerical simulation with 2-stape soot formation model of Magnussen. The result shows that soot formation mainly occurred in diffusion combustion phase of diesel pilot jet. Soot peak value is proportional to the first peak value of ROHR, and is found at around the same crank angle position with the second peak of ROHR. At a given engine speed and diesel content in the fuel, the highest soot peak value is obtained with slightly rich mixture whereas soot concentration in exhaust gas increases monotonically with increasing equivalence ratio. Increasing diesel content in the fuel increases both soot peak value and soot concentration in exhaust gas. At a given equivalence ratio and diesel content in the fuel, engine speed has a moderate effect on soot formation rate but a significant effect on soot combustion rate. Soot concentration in the exhaust gas practically vanished as equivalence ratio under 0.98 and 15% diesel content in the fuel. This is the ideal operation regime of bio-gas diesel dual fuel engine in view of soot emission control.

Modelling Soot Formation in Aviation Fuel Oxidation

2006 ◽  
Author(s):  
A. G. Kyne ◽  
M. Pourkashanian ◽  
C. W. Wilson
Keyword(s):  
Residence Time ◽  
Equivalence Ratio ◽  
Volume Fraction ◽  
Soot Formation ◽  
Soot Volume Fraction ◽  
Chemical Kinetic ◽  
Reaction Model ◽  
Aviation Fuel ◽  
Out Of Sample ◽  
The Impact

This study outlines the development of a new chemical kinetic surrogate aviation fuel air reaction mechanism which models up to four ring Polycyclic Aromatic Hydrocarbon (PAH) growth. A sensitivity analysis has been conducted to guide us in improving the correlation with modelled and measured species’ profiles in an n-decane – air combustion environment. It was reassuring that the mechanism could be successfully applied to an out of sample set of experimental profiles for acetylene combustion and showed a noticeable improvement over a previous reaction model. In order to calculate the soot volume fraction, a previously developed soot model was employed that accounts for soot particle coagulation, aggregation and surface growth. The impact of pressure, equivalence ratio and residence time on soot formation for a surrogate aviation fuel-air combustion in a Perfectly Stirred Reactor was also investigated. Generally speaking, the level of soot increased with increasing pressure, residence time and equivalence ratio.

Flame Radiation and Soot Emission From Partially Premixed Methane Counterflow Flames

2005 ◽  
Vol 128 (4) ◽  
pp. 361-367 ◽  
Author(s):  
Hemant P. Mungekar ◽  
Arvind Atreya
Keyword(s):  
Heat Transfer ◽  
Volume Fraction ◽  
Soot Volume Fraction ◽  
Soot Emission ◽  
Particulate Emission ◽  
Flame Radiation ◽  
Gas Radiation ◽  
Reaction Zones ◽  
Partial Premixing ◽  
Counterflow Flames

Motivated by heat transfer and environmental concerns, a study of flame radiation and soot particulate emission is reported for partial premixing in low strain-rate (<20s−1) methane counterflow flames. Temperature, OH concentration, and soot volume fraction distributions were measured along the stagnation streamline for progressive addition of oxygen to methane. These measurements along with an optically thin model for soot and gas radiation were used to study the effect of partial premixing on flame radiation and soot emission. It was found that with progressive partial premixing, the peak soot loading and the thickness of the soot zone first decreased and then increased, and while the gas radiation was enhanced, the gas radiative fraction (gas radiation per unit chemical energy release) showed a systematic decrease. The net radiative fraction (soot+gas), however, first decreased and then increased. A configuration with the soot zone spatially entrapped between the premixed and non-premixed reaction zones was experimentally found. This flame configuration has the potential to enhance radiative heat transfer while simultaneously reducing soot and NOx emissions.

Numerical Simulation of Dual-Fuel Compression-Ignition Engine in Part-Load Operating Condition With Double Injection

2016 ◽  
Author(s):  
Arash Jamali ◽  
M. Razi Nalim
Keyword(s):  
Natural Gas ◽  
Diesel Fuel ◽  
Optimal Operation ◽  
Pollutant Emissions ◽  
Dual Fuel ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Operating Condition ◽  
Part Load ◽  
Double Injection

Natural gas substitution for diesel can result in significant reductions in pollutant emissions. In addition, with a high ignition temperature and relatively low reactivity, natural gas can enable promising approaches to combustion engine design. In particular, the combination of low-reactivity natural gas and high-reactivity diesel may allow for optimal operation as a reactivity-controlled compression ignition (RCCI) engine, which has potential for high efficiency and low emissions. In this computational study, a lean mixture of natural gas is ignited by direct injection of diesel fuel in part-load operating condition in a model of the heavy-duty CAT3401 diesel engine. A multi-dimensional simulation was performed using a finite-volume computational code for fuel spray and combustion processes in the Reynolds-averaged Navier-Stokes (RANS) framework. Adaptive mesh refinement (AMR) and multi-zone reaction modeling enables simulation in a reasonable time. The latter approach avoids expensive kinetic calculations in every computational cell, with considerable speedup. The model produces encouraging agreement between the simulation and experimental data. For reasonable accuracy and computation cost, a minimum cell size of 0.2 millimeters is suggested for the natural gas-diesel (NGD) dual-fuel engine. The results reveal that in part-load operating condition, much of the CH4, which is used as surrogate fuel for natural gas, cannot burn. The main goal of this research work is to assess the possibility to improve the performance of Caterpillar-3401 engine in NGD dual-fuel operation by in-cylinder modification strategies. The results reveal that among different strategies, double injection of diesel fuel with an early main injection can reduce the unburned hydrocarbon (UHC) emission significantly.

Hydrogen-Enriched Biogas Premixed Charge Combustion and Emissions in DI and IDI Diesel Dual Fueled Engines: A Comparative Study

2021 ◽  
pp. 1-27
Author(s):  
Van Ga Bui ◽  
Thi Minh Tu Bui ◽  
Anh Tuan Hoang ◽  
Sandro Nizetic ◽  
Thanh Xuan Nguyen Thi ◽  
...  
Keyword(s):  
Comparative Study ◽  
Volume Fraction ◽  
Direct Injection ◽  
Soot Volume Fraction ◽  
Mixture Distribution ◽  
Combustion Products ◽  
Nox Emission ◽  
Dual Fuel ◽  
Auto Ignition ◽  
Co Concentration

Abstract The paper presents a comparative study on combustion and emissions of hydrogen-enriched biogas premixed charge in direct injection dual fuel (DIDF) engine and indirect injection dual fuel (IDIDF) engine. The results show that the IDIDF engine outperforms the DIDF engine in terms of higher indicative engine cycle work (Wi), lower emissions of CO, soot, and noise, but the disadvantage is higher NOx emission. Under the same fueling condition, the IDIDF engine's Wi is on average 6% higher than that of the DIDF engine, but the NOx concentration in the combustion products of the IDIDF engine is 1.5 times higher than that of the DIDF engine. The IDIDF engine creates the stratified mixture distribution with higher O2 concentration in the auxiliary combustion chamber, which is favorable for auto ignition and reduces the ignition delay. The biogas composition affects slightly CO, and soot emissions, but significantly affects NOx emission. When the methane composition in biogas increases from 60% to 80%, the soot volume fraction is approximately 0.1ppm in both types of combustion chambers; the CO concentration varies from 1.4-1.8%, meanwhile, the NOx concentration varies from 3000-5000ppm in the case of IDIDF engine and 2500-4500ppm in the case of DIDF engine. For both types of dual fuel engines, when engine speed increases, CO concentration, and the soot volume fraction increase, while Wi and NOx concentration decrease.

scholarly journals Effects of Injection Timing on Combustion and Emission Performance of Dual-Fuel Diesel Engine under Low to Medium Load Conditions

Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2349 ◽  
Author(s):  
Hua Zhou ◽  
Hong-Wei Zhao ◽  
Yu-Peng Huang ◽  
Jian-Hui Wei ◽  
Yu-Hui Peng
Keyword(s):  
Output Power ◽  
Substitution Rate ◽  
Pollutant Emissions ◽  
Dual Fuel ◽  
Injection Timing ◽  
Excess Air ◽  
Diesel Injection ◽  
Medium Speed ◽  
Hc Emissions ◽  
Load Conditions

A throttle can be installed on the intake pipe of a natural gas (NG)/diesel dual-fuel engine to control the excess air ratio of the air-fuel mixture by adjusting the air intake. Building on a previously proposed NG/diesel dual-fuel supply strategy using the adjustment of excess air ratio, this work further studied the effects of different injection timing schemes on output power, fuel efficiency, and pollutant emissions of a dual-fuel engine under low to medium load conditions. In the experiment, the engine was operated at a speed of 1600 r/min, under either low (27.1 N·m) or medium (50.6 N·m) loads, and the NG substitution rate was either 40%, 60%, or 80%. The effect of different injection timing schemes on the combustion performance of the engine under low to medium load conditions was studied based on in-cylinder pressure changes detected by a pressure sensor. Experimental results showed that under medium-speed low-load conditions and a NG substitution rate of 40%, setting the diesel injection timing to 27 °CA BTDC increased the engine output power by 9.03%, reduced the brake specific energy consumption (BSEC) by 13.33%, and effectively reduced CO, CO2, and HC emissions. Under medium-speed medium-load conditions with a NG substitution rate of 80%, setting the diesel injection timing to 25 °CA BTDC increased the engine output power by 14.62%, reduced the BSEC by 11.73%, and significantly reduced CO, CO2, and HC emissions.

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