Combustion Characteristics of Producer Gas in the Stationary Gas Engine

2011 ◽  
Author(s):  
Arnold M. Kim ◽  
James A. Smith ◽  
Jayson R. Wagler ◽  
Darryl D. Baldwin
Keyword(s):  
Performance Test ◽  
Laminar Flame ◽  
Model Development ◽  
Flame Temperature ◽  
Engine Performance ◽  
Combustion Characteristics ◽  
Gas Combustion ◽  
Wide Range ◽  
Test Engine ◽  
Explosive Reaction

Three syngases were selected from customer sites and the engine performance test was conducted on a single cylinder test engine (SCTE) to explore the engine operating limits and investigate the combustion characteristics for the simulation model development. Syngas has a wide range of lambda between the misfire and the detonation compared to conventional natural gas. Combustion of syngas 1 having no CH4 showed unique characteristics which are different from syngas 3. It appears that even a small amount of CH4 in the fuel would be important to lower the rate of the main branching reaction of hydrogen and mitigate the explosive reaction of the hydrogen. Lean operating limit of the tested syngas was observed when LFS (Laminar Flame Speed) and AFT (Adiabatic Flame Temperature) become around 5∼7 cm/s and 1660 ∼ 1720°C.

Control-Oriented Model Development and Experimental Validation for a Modern Diesel Engine

2020 ◽  
Author(s):  
Kuo Yang ◽  
Pingen Chen
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Model Development ◽  
Engine Performance ◽  
Operating Conditions ◽  
Least Square ◽  
Injection Timing ◽  
Model Based ◽  
Wide Range ◽  
Mean Square Errors

Abstract Modern Diesel engines have become highly complex multi-input multi-output systems. Controls of modern Diesel engines to meet various requirements such as high fuel efficiency and low NOx and particulate matter (PM) emissions, remain a great challenge for automotive control community. While model-based controls have demonstrated significant potentials in achieving high Diesel engine performance. Complete and high-fidelity control-oriented Diesel engine models are much needed as the foundations of model-based control system development. In this study, a semi-physical, mean-value control-oriented model of a turbocharged Diesel engine equipped with high-pressure exhaust gas recirculation (EGR) and variable geometry turbocharger (VGT) is developed and experimentally validated. The static calibration of Diesel engine model is achieved with the least-square optimization methodology using the experimental test data from a physical Diesel engine platform. The normalized root mean square errors (NRMSEs) of the calibration results are in the range of 0.1095 to 0.2582. The cross-validation results demonstrated that the model was capable of accurately capturing the engine torque output and NOx emissions with the control inputs of EGR, VGT and Start of Injection timing (SOI) in wide-range operating conditions.

Engine Capability Prediction for SI Engine Fueled With Syngas

2015 ◽  
Author(s):  
Hui Xu ◽  
Leon A. LaPointe
Keyword(s):  
Natural Gas ◽  
Solid Waste ◽  
Laminar Flame ◽  
Combustion Engine ◽  
Flame Temperature ◽  
Engine Performance ◽  
Nox Emissions ◽  
Lean Burn ◽  
Gaseous Fuels ◽  
Combustion Duration

There are increasing interests in converting solid waste or lignocellulosic biomass into gaseous fuels and using reciprocating internal combustion engine to generate electricity. A widely used technique is gasification. Gasification is a process where the solid fuel and air are introduced to a partial oxidation environment, and generate combustible gaseous called synthesis gas or syngas. Converting solid waste into gaseous fuel can reduce landfill and create income for process owners. However it can be very challenging to use syngas on a gaseous fueled spark ignited engine, such as a natural gas (NG) engine. NG engines are typically developed with pipeline quality natural gas (PQNG). NG engines can operate at lean burn spark ignited (LBSI), or stoichiometric with EGR spark ignited (SESI) conditions. This work discusses the LBSI engine condition. NG engines can perform very differently when fueled with nonstandard gaseous fuels such as syngas without appropriate tuning. It is necessary to evaluate engine performance in terms of combustion duration, relative knock propensity and NOx emissions for such applications. Due to constraints in time and resources it is often not feasible to test such fuel blends in the laboratory. An analytical method is needed to predict engine performance in a timely manner. This study investigated the possibility of using syngas on a spark ignited engine developed with PQNG. Engine performance was predicted using in house developed models and PQNG as the reference fuel. Laminar flame speed (LFS), adiabatic flame temperature (AFT) and Autoignition interval (AI) are used to predict combustion duration, engine out NOx and engine knock propensity relative to NG at the target Lambda values. Single cylinder research engine data obtained under lean burn conditions fueled with PQNG was selected as the baseline. LFS, AFT and AI of syngas were computed at reference conditions. Lambda of operation was predicted for syngas to provide the same burn rate as NG at the reference Lambda value for NG. Analysis shows that, using syngas at the selected Lambda, the engine can have less engine out NOx emissions and less knock propensity relative to NG at the same speed and load. Modifications to fuel system components may be required to avoid engine derate.

scholarly journals Theoretical Study of an Undisclosed Reaction Class: Direct H-Atom Abstraction from Allylic Radicals by Molecular Oxygen

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2916
Author(s):  
Yang Li ◽  
Jin Wu ◽  
Qian Zhao ◽  
Yingjia Zhang ◽  
Zuohua Huang
Keyword(s):  
Ab Initio ◽  
Molecular Oxygen ◽  
Rate Constants ◽  
Laminar Flame ◽  
Model Development ◽  
State Theory ◽  
Unsaturated Hydrocarbon ◽  
Rate Coefficients ◽  
Wide Range ◽  
Allylic Radical

The 1-methylallyl (C4H71-3) allylic radical is an important intermediate species in oxidation of linear C4 unsaturated hydrocarbons (1-butene, 2-butene, and 1,3-butadiene). This study reports the first high-level quantum chemical calculations for an undisclosed reaction class of this radical at intermediate to high temperatures: direct H-atom abstraction from terminal methyl group by molecular oxygen. Moreover, we systematically calculated rate constants for primary, secondary, and tertiary H-atom abstraction from the C4, C5, and C6 allylic radicals, respectively. Our results can be further used as rate rules for kinetic model development of unsaturated hydrocarbon oxidation. All calculations were implemented using two different ab initio solvers: Gaussian and ORCA, three sets of ab initio methods, and two different kinetic solvers: MultiWell and PAPR. Temperature dependent rate constants and thermochemistry were carried out based on transition state theory and statistical thermodynamics, respectively. H-atom abstraction from the primary site of C4 allylic radical is found to be faster than that from secondary and tertiary sites of C5 and C6 allylic radicals, contrary to common understanding. Barrier heights predicted by different ab initio solvers and methods are about 4–5 kcal/mol different, which results in a factor of 4–86 difference in rate constant predictions depending on the temperature. Using the Gaussian solver with Method 2 is found to be the most effective combination of predicting accurate rate constants when compared against experimental data. When comparing two kinetic solvers, both reaction rate coefficients and species thermochemistry show good agreement at a wide range of temperatures, except for the rate coefficients calculated for C5 and C6 reactions (about a factor of 5–17 and 3–4 differences were obtained, respectively). From an application point of view, we incorporated the calculation results into the AramcoMech2.0 model, and found systematic improvements for predicting ignition delay time, laminar flame speed and speciation targets of 2-butene oxidation.

Study of Fuel Composition Effects on Flashback Using a Confined Jet Flame Burner

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Brendan Shaffer ◽  
Zhixuan Duan ◽  
Vincent McDonell
Keyword(s):  
Natural Gas ◽  
Laminar Flame ◽  
Flame Temperature ◽  
Flame Speed ◽  
Fuel Composition ◽  
Laminar Flame Speed ◽  
Processing Scheme ◽  
High Hydrogen ◽  
Jet Flame ◽  
Wide Range

Flashback is the main operability issue associated with converting lean, premixed combustion systems from operation on natural gas to operation on high hydrogen content fuels. Most syngas fuels contain some amount of hydrogen (15–100%) depending on the fuel processing scheme. With this variability in the composition of syngas, the question of how fuel composition impacts flashback propensity arises. To address this question, a jet burner configuration was used to develop systematic data for a wide range of compositions under turbulent flow conditions. The burner consisted of a quartz burner tube confined by a larger quartz tube. The use of quartz allowed visualization of the flashback processes occurring. Various fuel compositions of hydrogen, carbon monoxide, and natural gas were premixed with air at equivalence ratios corresponding to constant adiabatic flame temperatures (AFT) of 1700 K and 1900 K. Once a flame was stabilized on the burner, the air flow rate would be gradually reduced while holding the AFT constant via the equivalence ratio until flashback occurred. Schlieren and intensified OH* images captured at high speeds during flashback allowed some additional understanding of what is occurring during the highly dynamic process of flashback. Confined and unconfined flashback data were analyzed by comparing data collected in the present study with existing data in the literature. A statistically designed test matrix was used which allows analysis of variance of the results to be carried out, leading to correlation between fuel composition and flame temperature with (1) critical flashback velocity gradient and (2) burner tip temperature. Using the burner tip temperature as the unburned temperature in the laminar flame speed calculations showed increased correlation of the flashback data and laminar flame speed as opposed to when the actual unburned gas temperature was used.

Study of Fuel Composition Effects on Flashback Using a Confined Jet Flame Burner

2012 ◽  
Author(s):  
Brendan Shaffer ◽  
Zhixuan Duan ◽  
Vincent McDonell
Keyword(s):  
Natural Gas ◽  
Laminar Flame ◽  
Flame Temperature ◽  
Flame Speed ◽  
Fuel Composition ◽  
Laminar Flame Speed ◽  
Processing Scheme ◽  
High Hydrogen ◽  
Jet Flame ◽  
Wide Range

Flashback is the main operability issue associated with converting lean, premixed combustion systems from operation on natural gas to operation on high hydrogen content fuels. Most syngas fuels contain some amount of hydrogen (15–100%) depending on the fuel processing scheme. With this variability in the composition of syngas, the question of how fuel composition impacts flashback propensity arises. To address this question, a jet burner configuration was used to develop systematic data for a wide range of compositions under turbulent flow conditions. The burner consisted of a quartz burner tube confined by a larger quartz tube. The use of quartz allowed visualization of the flashback processes occurring. Various fuel compositions of hydrogen, carbon monoxide, and natural gas were premixed with air at equivalence ratios corresponding to constant adiabatic flame temperatures (AFT) of 1700 K and 1900 K. Once a flame was stabilized on the burner, the air flow rate would be gradually reduced while holding the AFT constant via the equivalence ratio until flashback occurred. Schlieren and intensified OH* images captured at high speeds during flashback allowed some additional understanding of what is occurring during the highly dynamic process of flashback. Confined and unconfined flashback data were analyzed by comparing data collected in the present study with existing data in the literature. A statistically designed test matrix was used which allows analysis of variance of the results to be carried out, leading to correlation between fuel composition and flame temperature with (1) critical flashback velocity gradient and (2) burner tip temperature. Using the burner tip temperature as the unburned temperature in the laminar flame speed calculations showed increased correlation of the flashback data and laminar flame speed as opposed to when the actual unburned gas temperature was used.

scholarly journals Numerical Study on the Effect of Fuel Rich n-Heptane on In-Cylinder Fuel Reforming Characteristics in an HCCI Engine

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Weijian Zhou ◽  
Song Zhou ◽  
Hongyuan Xi ◽  
Majed Shreka ◽  
Zhao Zhang
Keyword(s):  
Laminar Flame ◽  
Numerical Study ◽  
Flame Temperature ◽  
Engine Performance ◽  
Chemical Effect ◽  
Fuel Reforming ◽  
Compression Ignition Engine ◽  
Thermodynamic Effects ◽  
Reduce Emissions ◽  
Reforming Gas

The effect of in-cylinder fuel reforming on an n-heptane homogenous charge compression ignition engine has been studied. A dedicated cylinder without a complex control system is proposed for fuel enrichment reforming, which can provide part of the power for the engine. The effects of different reforming species on engine performance and chemical reaction have been simulated by a numerical study. By comparing the combustion characteristics of n-heptane with different equivalence ratios in the reformer cylinder, the optimal n-heptane equivalence ratio has been determined. The enrichment of n-heptane produces sufficient hydrogen (H2) and carbon monoxide (CO), while the hydrocarbon content of the reforming species was low. It was found that the addition of reforming species retards the combustion phase of n-heptane, thereby providing a means of controlling engine performance. In addition, the laminar flame speed and the adiabatic flame temperature of n-heptane increased by adding H2 and CO. Fuel reforming reduced the emission of ethylene, propyne, allene, propylene, butadiene, and nitrogen oxide, but it increased the emissions of acetylene and CO. Moreover, chemical, dilution, and thermodynamic effects of the reforming gas have been studied. The results showed that the chemical effect of the reforming species was less significant than the dilution and thermodynamic effects. These simulation results showed that in-cylinder fuel reforming can effectively improve engine performance and thereby reduce emissions.

scholarly journals Numerical study of the laminar flame propagation in ethane-air mixtures

2014 ◽  
Vol 12 (3) ◽  
pp. 391-402 ◽  
Author(s):  
Venera Giurcan ◽  
Domnina Razus ◽  
Maria Mitu ◽  
Dumitru Oancea
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Laminar Flame ◽  
Numerical Study ◽  
Flame Temperature ◽  
Chemical Species ◽  
Main Reaction ◽  
Flame Thickness ◽  
Wide Range

AbstractThe structure of premixed free one-dimensional laminar ethane-air flames was investigated by means of numerical simulations performed with a detailed mechanism (GRI-Mech version 3.0) by means of COSILAB package. The work provides data on ethane-air mixtures with a wide range of concentrations ([C2H6] = 3.0–9.5 vol.%) at initial temperatures between 300 and 550 K and initial pressures between 1 and 10 bar. The simulations deliver the laminar burning velocities and the profiles of temperature, chemical species concentrations and heat release rate across the flame front. The predicted burning velocities match well the burning velocities measured in various conditions, reported in literature. The influence of initial concentration, pressure and temperature of ethane-air mixtures on maximum flame temperature, heat release rate, flame thickness and peak concentrations of main reaction intermediates is examined and discussed.

Calculation of Laminar Flame Speed and Autoignition Delay at High Temperature and Pressures

2013 ◽  
Author(s):  
Hui Xu ◽  
Leon A. LaPointe
Keyword(s):  
High Temperature ◽  
Relative Humidity ◽  
Laminar Flame ◽  
Engine Performance ◽  
Simulation Software ◽  
Flame Speed ◽  
Laminar Flame Speed ◽  
Gaseous Fuels ◽  
Wide Range ◽  
Engine Development

Recent developments in emissions regulations, costs of conventional fuels, and new gas extraction drilling technologies have resulted in an increased emphasis in gaseous fueled spark ignited engine development. However the composition of gaseous fuels can vary greatly. Homogenous Charge Spark Ignited (HCSI) engine performance is heavily dependent upon fuel properties, and robust engine design to utilize gaseous fuels must accommodate these fuel property variances. Accurate prediction of fuel energy release characteristics and knock tendency is critical in the process of HCSI engine development. Combustion characteristics, such as Laminar Flame Speed (LFS) and Autoignition Interval (AI), are used to characterize performance of various gaseous fuels in HCSI engine applications. Combustion duration is related to the LFS. The likelihood of Knock is related to the AI. Overall engine performance is estimated by appropriately incorporating these parameters into cycle simulation software. Experimental data of LFS is often at low temperature and low pressure and thus does not represent the high temperature and pressure conditions typically prevalent in HCSI engine combustion chambers at the time of ignition. Lack of reliable LFS data at high temperature and pressures represents a major opportunity of development for better engine performance simulations [1]. In this paper, the commercially available chemical kinetics solver Chemkin Pro using an appropriate mechanism was employed to compute LFS and AI at typical HCSI engine in-cylinder conditions. It is challenging to compute LFS at such extreme conditions mainly because of autoignition as a competing process. This paper describes development of a robust methodology to compute LFS over a wide range of Temperature (up to 1300 K), Pressure (up to 250 bar), Relative Humidity, and Lambda for Methane. A regression for LFS with Pressure, Temperature, Lambda, and Relative Humidity as independent variables was generated for Methane. Methodology robustness was suggested with similar LFS calculations using other fuels. The form of the regression is similar for all of the fuels investigated.

scholarly journals Performance, Emission and Combustion Characteristics of a Diesel Engine Powered by Macadamia and Grapeseed Biodiesels

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2748 ◽  
Author(s):  
Abul Kalam Azad ◽  
Julian Adhikari ◽  
Pobitra Halder ◽  
Mohammad G. Rasul ◽  
Nur M. S. Hassan ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Engine Performance ◽  
Combustion Characteristics ◽  
Commercial Application ◽  
Engine Emissions ◽  
Physiochemical Properties ◽  
Brake Thermal Efficiency ◽  
Wide Range ◽  
Minimal Reduction

Biodiesel is an alternative, eco-friendly and renewable source of energy. It can be produced from a wide range of feedstocks which can be grown in marginal land use. It has drawn more attention to the researchers. In this study, the oil extraction, biodiesel conversion, and physiochemical properties of Macadamia (Macadamia integrifolia) and Grapeseed (Vitis vinifera) biodiesels are presented. The experimental investigation of diesel engine performance, emissions and combustion characteristics were conducted using B5 (5% biodiesel and 95% diesel by volume) and B10 (10% biodiesel and 90% diesel by volume) blends. The engine performance parameters, such as brake power (BP), brake specific fuel consumption (BSFC), and brake thermal efficiency (BTE) have been investigated in this experiment. The emission parameters, for example, carbon monoxide (CO), the ratio of CO2/CO, nitrogen oxide (NOx), hydrocarbon (HC), particulate matter (PM) have been measured during the experiment. Finally, the combustion parameters such as cylinder pressure (CP) were recorded, and heat release rate (HRR) was analysed and compared with that of diesel fuel. The study revealed that the Macadamia biodiesel performed better than Grapeseed biodiesel and behaved closely to that of diesel fuel. A significant reduction of engine emissions was found in the case of Macadamia biodiesel with a minimal reduction of engine performance. Further analysis of energy, exergy and tribological characteristics of the Macadamia biodiesel is recommended for assessing its feasibility for commercial application.

scholarly journals Rancang bangun dan uji performansi mesin pencampur beberuk, makanan khas Lombok

2021 ◽  
Vol 11 (1) ◽  
pp. 10
Author(s):  
A. Ansar ◽  
S. Muttalib ◽  
R. Sabani ◽  
R. Kustina
Keyword(s):  
Performance Test ◽  
Production Capacity ◽  
Engine Performance ◽  
Machine Design ◽  
Market Demand ◽  
Test Results ◽  
Mixing Chamber ◽  
Test Engine ◽  
Increase Productivity ◽  
Time Variations

During this time the process of making beberuk was still done traditionally using a mortar as a mixer, so that production is very limited, while the market demand is quite high. To increase productivity, it is necessary to design a machine that can increase the production capacity of the beberuk. The research method begins with the mixing machine design process, then continues with the assembly process and engine performance test. The design of the mixing machine is done with two approaches namely functional approach and structural approach. Test engine performance on 3 power variations namely 144, 168, and 192 watts and 3-time variations namely 30, 45, and 60 seconds. The results showed that the cylindrical mixing chamber has a diameter of 20 cm and a height of 50 cm. The mixing tube has a rectangular hopper with dimensions of 37 cm long and 9 cm wide. Engine performance test results showed the best results on 168 watts of power treatment and 30 seconds with the results of mixing not bubbly and still looks tomato chunks and is not too smooth according to the standard beberuk food.

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