scholarly journals Spark ignition engine performance and emissions in a high compression engine using biogas and methane mixtures without knock occurrence

2015 ◽  
Vol 19 (6) ◽  
pp. 1919-1930 ◽  
Author(s):  
Montoya Gómez ◽  
Arrieta Amell ◽  
Lopez Zapata
Keyword(s):  
Output Power ◽  
Compression Ratio ◽  
Thermal Efficiency ◽  
Combustion Engine ◽  
Maximum Output Power ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Maximum Output ◽  
Engine Operation ◽  
High Compression

With the purpose to use biogas in an internal combustion engine with high compression ratio and in order to get a high output thermal efficiency, this investigation used a diesel engine with a maximum output power 8.5 kW, which was converted to spark ignition mode to use it with gaseous fuels. Three fuels were used: Simulated biogas, biogas enriched with 25% and 50% methane by volume. After conversion, the output power of the engine decreased by 17.64% when using only biogas, where 7 kW was the new maximum output power of the engine. The compression ratio was kept at 15.5:1, and knocking did not occur during engine operation. Output thermal efficiency operating the engine in SI mode with biogas enriched with 50% methane was almost the same compared with the engine running in diesel-biogas dual mode at full load and was greater at part loads. The dependence of the diesel pilot was eliminated when biogas was used in the engine converted in SI mode. The optimum condition of experiment for the engine without knocking was using biogas enriched with 50% methane, with 12 degrees of spark timing advance and equivalence ratio of 0.95, larger output powers and higher values of methane concentration lead the engine to knock operation. The presence of CO2 allows operating engines at high compression ratios with normal combustion conditions. Emissions of nitrogen oxides, carbon monoxide and unburnt methane all in g/kWh decreased when the biogas was enriched with 50% methane.

Operation of a Spark Ignition Engine With High Compression Ratio Using Biogas Blended With Natural Gas, Propane, and Hydrogen

2018 ◽  
Vol 141 (5) ◽  
Author(s):  
Juan Pablo Gómez Montoya ◽  
Andrés A. Amell ◽  
Daniel B. Olsen
Keyword(s):  
Natural Gas ◽  
Output Power ◽  
Compression Ratio ◽  
Maximum Output Power ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Maximum Output ◽  
High Compression Ratio ◽  
Operational Conditions ◽  
High Compression

This research evaluated the operational conditions for a diesel engine with high compression ratio (CR) converted to spark ignition (SI), under stable combustion conditions close to the knocking threshold. The main fuel used in the engine was biogas, which was blended with natural gas, propane, and hydrogen. The engine limit to test the maximum output power was using the knocking threshold; just below the knocking threshold, the output power and generating efficiency are the highest for each blend. Leaner mixtures increased the engine knocking tendency because the required increase in the % throttle reduced the pressure drop at the inlet stroke and increased the mixture pressure at the end of the compression stroke, which finally reduced the ignition delay time of the end gas and increased the knocking tendency of the engine for all the blends. Therefore, the output power should be decreased to operate the engine below to the knocking threshold. Purified biogas achieved the highest output power and generating efficiency compared with the other blends and the original diesel operation; this blend was operated with five equivalence ratios. Purified biogas exhibits an optimal balance between knocking resistance, low heating value, flame speed, and energy density.

scholarly journals Performance of direct injected propane and gasoline in a high stroke-to-bore ratio SI engine: Pathways to diesel efficiency parity with ultra low soot

2021 ◽  
pp. 146808742110069
Author(s):  
D Splitter ◽  
V Boronat ◽  
FDF Chuahy ◽  
J Storey
Keyword(s):  
Particle Size ◽  
Compression Ratio ◽  
Thermal Efficiency ◽  
High Efficiency ◽  
Spark Ignition ◽  
Liquid Films ◽  
Spark Ignition Engine ◽  
Gasoline Direct Injection ◽  
Combustion Stability ◽  
Engine Operation

This work explores pathways to achieve diesel-like, high-efficiency combustion with stoichiometric 3-way catalyst compatible combustion in a single-cylinder spark ignition (SI) research engine. A unique high stroke-to-bore engine design (1.5:1) with cooled exhaust gas recirculation (EGR) and high compression ratio ( rc) was used to improve engine efficiency by up to 30% compared with a production turbocharged gasoline direct injection spark ignition engine. Engine experiments were conducted with both 91 RON E10 gasoline and liquified petroleum gas (LPG) (i.e. autogas) and were compared to legacy gasoline data on the production engine. Geometric compression ratio ( rc) of 13.3:1 was used for both fuels with additional experiments at 16.8:1 for LPG only. Measurements of exhaust soot particle size and number concentrations were made with both fuels. Significant reduction in soot particles across the whole particle size range were achieved with LPG due to the elimination of in-cylinder liquid films. The effects of EGR, late intake valve closing (IVC) and fuel characteristics were investigated through their effects on efficiency, combustion stability and soot production. Results of 47% gross thermal efficiency, and 45% net thermal efficiency at stoichiometric engine operation, at up to 17 bar IMEP and 2000 r/min with 16.8:1 rc were achieved with LPG. Estimated brake efficiency values were compared to a contemporary medium duty diesel engine illustrating the benefits of the chosen path for achieving diesel efficiency parity.

Simulation of Extended Expansion Lean Burn Spark Ignition Engine

2004 ◽  
Author(s):  
A. Manivannan ◽  
R. Ramprabhu ◽  
P. Tamilporai ◽  
S. Chandrasekaran
Keyword(s):  
Heat Transfer ◽  
Compression Ratio ◽  
Thermal Efficiency ◽  
Numerical Study ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Valve Closure ◽  
Intake Valve ◽  
Lean Burn ◽  
Atkinson Cycle

This paper deals with Numerical Study of 4-stoke, Single cylinder, Spark Ignition, Extended Expansion Lean Burn Engine. Engine processes are simulated using thermodynamic and global modeling techniques. In the simulation study following process are considered compression, combustion, and expansion. Sub-models are used to include effect due to gas exchange process, heat transfer and friction. Wiebe heat release formula was used to predict the cylinder pressure, which was used to find out the indicated work done. The heat transfer from the cylinder, friction and pumping losses also were taken into account to predict the brake mean effective pressure, brake thermal efficiency and brake specific fuel consumption. Extended Expansion Engine operates on Otto-Atkinson cycle. Late Intake Valve Closure (LIVC) technique is used to control the load. The Atkinson cycle has lager expansion ratio than compression ratio. This is achieved by increasing the geometric compression ratio and employing LIVC. Simulation result shows that there is an increase in thermal efficiency up to a certain limit of intake valve closure timing. Optimum performance is attained at 90 deg intake valve closure (IVC) timing further delaying the intake valve closure reduces the engine performance.

scholarly journals The Operating Features of a Stoichiometric, Ammonia and Gasoline Dual Fueled Spark Ignition Engine

2006 ◽  
Author(s):  
Shawn M. Grannell ◽  
Dennis N. Assanis ◽  
Stanislav V. Bohac ◽  
Donald E. Gillespie
Keyword(s):  
Compression Ratio ◽  
Thermal Efficiency ◽  
Maximum Load ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Gaseous Ammonia ◽  
Spark Ignition Engines ◽  
Stoichiometric Mixture ◽  
Brake Thermal Efficiency ◽  
Practical Operation

An overall stoichiometric mixture of air, gaseous ammonia and gasoline was metered into a single cylinder, variable compression ratio, supercharged CFR engine at varying ratios of gasoline to ammonia. The engine was operated such that the combustion was knock-free with minimal roughness for all loads ranging from idle up to a maximum load in the supercharge regime. For a given load, speed, and compression ratio there was a range of ratios of gasoline to ammonia for which knock-free, smooth firing was obtained. This range was investigated at its roughness limit and also at its knock limit. If too much ammonia was used, then the engine fired with an excessive roughness. If too much gasoline was used, then knock-free combustion could not be obtained while the maximum brake torque spark advance was maintained. Stoichiometric operation on gasoline alone was also investigated, for comparison. It was found that a significant fraction of the gasoline used in spark ignition engines could be replaced with ammonia. Operation on mostly gasoline was required near idle. However, mostly ammonia could be used at high load. Operation on ammonia alone was possible at some of the supercharged load points. Generally, the use of ammonia or ammonia with gasoline allowed knock-free operation at higher compression ratios and higher loads than could be obtained with the use of gasoline alone. The use of ammonia/gasoline allowed practical operation at a compression ratio of 12:1 whereas the limit for gasoline alone was 9:1. When running on ammonia/gasoline the engine could be operated at brake mean effective pressures that were more than 50% higher than those achieved with the use of gasoline alone. The maximum brake thermal efficiency achieved with the use of ammonia/gasoline was 32.0% at 10:1 compression ratio and BMEP = 1025 kPa. The maximum brake thermal efficiency possible for gasoline was 24.6% at 9:1 and BMEP = 570 kPa.

scholarly journals ANN Modelling of Propane-Powered 4-Stroke Spark Ignition Engine

2017 ◽  
Vol 11 (10) ◽  
pp. 1
Author(s):  
Jehad A. A. Yamin
Keyword(s):  
Experimental Data ◽  
Compression Ratio ◽  
Thermal Efficiency ◽  
Equivalence Ratio ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Ann Model ◽  
Spark Plug ◽  
Parametric Studies

An ANN model was developed by the authors and tested against experimental data available for an engine as supplied in the manual by the manufacturers. The model was found to perform excellently well by showing similar trends of performance for this engine as well as other engines for which the necessary data was available. This model was then used to perform some parametric studies to improve the performance of an engine using LPG (mainly Propane C3H8) as a fuel. This paper presents discussion on some of the parameters that affect the engine’s thermal efficiency with suggestions to improve it. The effect of equivalence ratio, compression ratio and spark plug location at different speeds on the thermal efficiency have been studied. Based on the engine and the range of variables studied it was found that the best spark plug location was 0.395 for all equivalence ratios studied at CR = 9.

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