Optical and thermodynamic investigations of a methane and hydrogen blend fueled large bore engine

2022 ◽  
pp. 146808742110667
Author(s):  
Stephan Karmann ◽  
Stefan Eicheldinger ◽  
Maximilian Prager ◽  
Georg Wachtmeister

The following paper presents thermodynamic and optical investigations of the natural flame and OH radical chemiluminescence of a hydrogen enriched methane combustion compared to natural gas combustion. The engine under investigation is a port-fueled unscavenged prechamber 4.8 L single cylinder large bore engine. The blends under consideration are 2%V, 5%V,10%V, and 40%V of hydrogen expected to be blended within existing natural gas grids in a short and mid-term timeline in order to store green energy from solar and wind. These fuel blends could be used for stabilization of the energy supply by reconverting the renewable fuel CH4/H2 in combined heat and power plants. As expected, admixture of hydrogen extends the ignition limits of the fuel mixture toward lean ranges up to an air-fuel equivalence ratio of almost 2. No negative effect on combustion is observed up to an admixture of 40%V hydrogen. At 40%V hydrogen, abnormal combustion like backfire occurs at an air-fuel equivalence ratio of 1.5. The higher mixtures exhibit increased nitrogen oxide emissions due to higher combustion chamber temperatures, while methane slip and CO emissions are reduced due to more complete combustion. The optical investigation of the natural flame and OH radical chemiluminescence are in good agreement with the thermodynamic results verifying the more intense combustion of the fuel blends by means of the chemiluminescence intensity. Further, lube oil combustion and a continuing luminescence after the thermodynamic end of combustion are observed.

Author(s):  
A. P. Shaikin ◽  
I. R. Galiev

The article analyzes the influence of chemical composition of hythane (a mixture of natural gas with hydrogen) on pressure in an engine combustion chamber. A review of the literature has showed the relevance of using hythane in transport energy industry, and also revealed a number of scientific papers devoted to studying the effect of hythane on environmental and traction-dynamic characteristics of the engine. We have studied a single-cylinder spark-ignited internal combustion engine. In the experiments, the varying factors are: engine speed (600 and 900 min-1), excess air ratio and hydrogen concentration in natural gas which are 29, 47 and 58% (volume).The article shows that at idling engine speed maximum pressure in combustion chamber depends on excess air ratio and proportion hydrogen in the air-fuel mixture – the poorer air-fuel mixture and greater addition of hydrogen is, the more intense pressure increases. The positive effect of hydrogen on pressure is explained by the fact that addition of hydrogen contributes to increase in heat of combustion fuel and rate propagation of the flame. As a result, during combustion, more heat is released, and the fuel itself burns in a smaller volume. Thus, the addition of hydrogen can ensure stable combustion of a lean air-fuel mixture without loss of engine power. Moreover, the article shows that, despite the change in engine speed, addition of hydrogen, excess air ratio, type of fuel (natural gas and gasoline), there is a power-law dependence of the maximum pressure in engine cylinder on combustion chamber volume. Processing and analysis of the results of the foreign and domestic researchers have showed that patterns we discovered are applicable to engines of different designs, operating at different speeds and using different hydrocarbon fuels. The results research presented allow us to reduce the time and material costs when creating new power plants using hythane and meeting modern requirements for power, economy and toxicity.


Gas Turbines ◽  
10.5772/10208 ◽  
2010 ◽  
Author(s):  
Z.R. Ismagilov ◽  
M.A. Kerzhentsev ◽  
S.A. Yashnik ◽  
N.V. Shikina ◽  
A.N. Zagoruiko ◽  
...  

2019 ◽  
Vol 4 (1) ◽  
pp. 67-71
Author(s):  
Amjd Ibraheem ◽  
Ferenc Szodrai

Traditional power plants still the dominating power source for all the major industries and powerdemanding facilities, the most crucial facility for the whole plant operations is the industrial boiler which generatessteam, heating energy or electrical power. Boilers generate energy by combustion. The improvement of combustion efficiency could greatly influence the energy consumption and will make the boiler more efficient and cleaner (less emissions), that’s why it is important to understand the combustion and thermal flow behaviours inside the boiler. Beside experimental testing, computational work nowadays becoming more and more important due to lower cost and acceptable accuracy with minimum error. With numerical calculations method, the computational model created by a Computational Fluid Dynamics (CFD) software could reduce a lot of trial and error on experimental work. In this paper utilizing the ANSYS FLUENT 19.1 software to make crate the combustion model. The ratio of air to fuel mixture, the equivalency factor, mass flow rate of the mixture, velocity, mass fractions of the mixture components (fuel and air) and their temperatures will serve as the input parameter while the exhaust gase component mass fraction, temperature, mass flow and velocity will be monitored.


2016 ◽  
Vol 16 (6) ◽  
pp. 3843-3863 ◽  
Author(s):  
Sally Newman ◽  
Xiaomei Xu ◽  
Kevin R. Gurney ◽  
Ying Kuang Hsu ◽  
King Fai Li ◽  
...  

Abstract. Large urban emissions of greenhouse gases result in large atmospheric enhancements relative to background that are easily measured. Using CO2 mole fractions and Δ14C and δ13C values of CO2 in the Los Angeles megacity observed in inland Pasadena (2006–2013) and coastal Palos Verdes peninsula (autumn 2009–2013), we have determined time series for CO2 contributions from fossil fuel combustion (Cff) for both sites and broken those down into contributions from petroleum and/or gasoline and natural gas burning for Pasadena. We find a 10 % reduction in Pasadena Cff during the Great Recession of 2008–2010, which is consistent with the bottom-up inventory determined by the California Air Resources Board. The isotopic variations and total atmospheric CO2 from our observations are used to infer seasonality of natural gas and petroleum combustion. The trend of CO2 contributions to the atmosphere from natural gas combustion is out of phase with the seasonal cycle of total natural gas combustion seasonal patterns in bottom-up inventories but is consistent with the seasonality of natural gas usage by the area's electricity generating power plants. For petroleum, the inferred seasonality of CO2 contributions from burning petroleum is delayed by several months relative to usage indicated by statewide gasoline taxes. Using the high-resolution Hestia-LA data product to compare Cff from parts of the basin sampled by winds at different times of year, we find that variations in observed fossil fuel CO2 reflect seasonal variations in wind direction. The seasonality of the local CO2 excess from fossil fuel combustion along the coast, on Palos Verdes peninsula, is higher in autumn and winter than spring and summer, almost completely out of phase with that from Pasadena, also because of the annual variations of winds in the region. Variations in fossil fuel CO2 signals are consistent with sampling the bottom-up Hestia-LA fossil CO2 emissions product for sub-city source regions in the LA megacity domain when wind directions are considered.


Author(s):  
Munidhar Biruduganti ◽  
Sreenath Gupta ◽  
Bipin Bihari ◽  
Raj Sekar

Air Separation Membranes (ASM) could potentially replace Exhaust Gas Recirculation (EGR) technology in engines due to the proven benefits in NOx reduction but without the drawbacks of EGR. Previous investigations of Nitrogen Enriched Air (NEA) combustion using nitrogen bottles showed up to 70% NOx reduction with modest 2% nitrogen enrichment. The investigation in this paper was performed with an ASM capable of delivering at least 3.5% NEA to a single cylinder spark ignited natural gas engine. Low Temperature Combustion (LTC) is one of the pathways to meet the mandatory ultra low NOx emissions levels set by regulatory agencies. In this study, a comparative assessment is made between natural gas combustion in standard air and 2% NEA for different engine loads. Enrichment beyond this level degraded engine performance in terms of power density, Brake Thermal Efficiency (BTE), and unburned hydrocarbon (UHC) emissions for a given equivalence ratio. The ignition timing was optimized to yield maximum brake torque for standard air and NEA. The parasitic loss associated with the usage of ASM technology is presented. It was observed that with 2% NEA, for a similar fuel quantity, the equivalence ratio (Ψ) increases by 0.1 relative to standard air conditions. Analysis showed that lean burn operation along with NEA could pave the pathway for realizing lower NOx emissions with a slight penalty in BTE.


2019 ◽  
Vol 16 (1) ◽  
pp. 36-42
Author(s):  
Hernando Alexander Yepes-Tumay ◽  
Arley Cardona-Vargas

The effect of ethane on combustion and natural gas autoignition was studied in the present paper. Two fuel mixture of natural gas with high ethane content were considered, 75% CH4 – 25% C2H6 (mixture 1), and 50% CH4 – 50% C2H6 (mixture 2). Natural gas combustion incidence was analyzed through the calculation of energy properties and the ignition delay time numerical calculations along with an ignition mode analysis. Specifically, the strong ignition limit was calculated to determine the effect of ethane on natural gas autoignition. According to the results, ignition delay time decreases for both mixtures in comparison with pure methane. The strong ignition limit shifts to lower temperatures when ethane is present in natural gas chemical composition.  


Author(s):  
Munidhar Biruduganti ◽  
Sreenath Gupta ◽  
Bipin Bihari ◽  
Steve McConnell ◽  
Raj Sekar

Air Separation Membranes (ASM) could potentially replace Exhaust Gas Recirculation (EGR) technology in engines due to the proven benefits in NOx reduction but without the drawbacks of EGR. Previous investigations of Nitrogen Enriched Air (NEA) combustion using nitrogen bottles showed up to 70% NOx reduction with modest 2% nitrogen enrichment. The investigation in this paper was performed with an ASM capable of delivering at least 3.5% NEA to a single cylinder spark ignited natural gas engine. Low Temperature Combustion (LTC) is one of the pathways to meet the mandatory ultra low NOx emissions levels set by regulatory agencies. In this study, a comparative assessment is made between natural gas combustion in standard air and 2% NEA. Enrichment beyond this level degraded engine performance in terms of power density, Brake Thermal Efficiency (BTE), and unburned hydrocarbon (UHC) emissions for a given equivalence ratio. The ignition timing was optimized to yield maximum brake torque for standard air and NEA. Subsequently, conventional spark ignition (SI) was replaced by laser ignition (LI) to extend lean ignition limit. Both ignition systems were studied under a wide operating range from ψ: 1.0 to the lean misfire limit. It was observed that with 2% NEA, for a similar fuel quantity, the equivalence ratio (Ψ) increases by 0.1 relative to standard air conditions. Analysis showed that lean burn operation along with NEA and alternative ignition source such as LI could pave the pathway for realizing lower NOx emissions with a slight penalty in BTE.


Author(s):  
Munidhar Biruduganti ◽  
Sreenath Gupta ◽  
Bipin Bihari ◽  
Steve McConnell ◽  
Raj Sekar

Air separation membranes (ASMs) could potentially replace exhaust gas recirculation (EGR) technology in engines due to the proven benefits in NOx reduction but without the drawbacks of EGR. Previous investigations of nitrogen-enriched air (NEA) combustion using nitrogen bottles showed up to 70% NOx reduction with modest 2% nitrogen enrichment. The investigation in this paper was performed with an ASM capable of delivering at least 3.5% NEA to a single-cylinder spark-ignited natural gas engine. Low temperature combustion is one of the pathways to meet the mandatory ultra low NOx emissions levels set by regulatory agencies. In this study, a comparative assessment is made between natural gas combustion in standard air and 2% NEA. Enrichment beyond this level degraded engine performance in terms of power density, brake thermal efficiency (BTE), and unburned hydrocarbon emissions for a given equivalence ratio. The ignition timing was optimized to yield maximum brake torque for standard air and NEA. Subsequently, conventional spark ignition was replaced by laser ignition (LI) to extend lean ignition limit. Both ignition systems were studied under a wide operating range from ψ:1.0 to the lean misfire limit. It was observed that with 2% NEA, for a similar fuel quantity, the equivalence ratio (Ψ) increases by 0.1 relative to standard air conditions. Analysis showed that lean burn operation along with NEA and alternative ignition source, such as LI, could pave the pathway for realizing lower NOx emissions with a slight penalty in BTE.


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