Experimental investigations of the combustion efficiency for fire load calculations

2015 ◽  
Vol 57 (10) ◽  
pp. 843-849 ◽  
Author(s):  
Christian Kusche ◽  
Christian Knaust ◽  
Sarah-Katharina Hahn ◽  
Ulrich Krause
2021 ◽  
pp. 146808742110169
Author(s):  
Zhongnan Ran ◽  
Jon Longtin ◽  
Dimitris Assanis

Solid oxide fuel cell – internal combustion engine (SOFC-ICE) hybrid systems are an attractive solution for electricity generation. The system can achieve up to 70% theoretical electric power conversion efficiency through energy cascading enabled by utilizing the anode off-gas from the SOFC as the fuel source for the ICE. Experimental investigations were conducted with a single cylinder Cooperative Fuel Research (CFR) engine by altering fuel-air equivalence ratio (ϕ), and compression ratio (CR) to study the engine load, combustion characteristics, and emissions levels of dry SOFC anode off-gas consisting of 33.9% H2, 15.6% CO, and 50.5% CO2. The combustion efficiency of the anode off-gas was directly evaluated by measuring the engine-out CO emissions. The highest net-indicated fuel conversion efficiency of 31.3% occurred at ϕ  = 0.90 and CR = 13:1. These results demonstrate that the anode off-gas can be successfully oxidized using a spark ignition combustion mode. The fuel conversion efficiency of the anode tail gas is expected to further increase in a more modern engine architecture that can achieve increased burn rates in comparison to the CFR engine. NOx emissions from the combustion of anode off-gas were minimal as the cylinder peak temperatures never exceeded 1800 K. This experimental study ultimately demonstrates the viability of an ICE to operate using an anode off-gas, thus creating a complementary role for an ICE to be paired with a SOFC in a hybrid power generation plant.


Author(s):  
Maria Grazia De Giorgi ◽  
Aldebara Sciolti ◽  
Stefano Campilongo ◽  
Antonio Ficarella

Experimental investigations were performed on a non-premixed liquid fuel-lean burner. The present work aims to the development of a methodology for the recognition of flame instability regimes in industrial and aeronautical burners. Instability, in fact, is an unpleasant aspect of combustive system that negatively impacts on combustion efficiency. The online monitoring of the occurrence of instability conditions, permits to adjust combustion parameters (as fuel or air mass flow, temperature, pressure, etc.) and to stabilize again the flame. High speed visualization systems are promising methods for on-line combustion monitoring. In this study two high speed visualization systems in the visible range and in the infrared spectral region were applied to characterize combustion efficiency and flame stability. Different processing techniques were used to extract representative data from flame images. Wavelet Decomposition and Spectral analysis of pixel intensities of flame images were used for feature extraction. Finally a statistical analysis was performed to identify the most unstable regions of the flame by the pixel intensity variance.


Author(s):  
Digvijay B. Kulshreshtha ◽  
S. A. Channiwala

The development of the combustion chamber for 20kW gas turbine unit using kerosene type fuel has been undertaken keeping in view the basic requirements of a good combustion chamber, namely, high combustion efficiency, low pressure loss, smooth ignition, wide stability limits, size and shape compatible with engine envelop, low emissions of smoke, unburned fuel and gaseous pollutant species, durability and ease of maintenance. A sophisticated experimental test rig has then been developed to investigate over a wide range of air/fuel ratios for the temperature profiles at the few axial and liner wall locations of this combustion chamber. The range of overall air/fuel ratios considered varies from 22.7396 to 152.4 i.e. Rich Air/Fuel Mixture to Lean Air/Fuel Mixture Range. The temperature profiles for centerline and liner wall for eight different air/fuel ratios are summarized here. The two air/fuel ratios selected are near the designed value of 118.34. It could be concluded from the results that the air/fuel ratio of 122.106 gives the best results for centerline temperature and the liner wall temperature as well as the exit temperature profile. This is very near to the designed air/fuel ratio of 118.34. The temperatures of near 1400 °C achieved at the centerline of the combustion chamber and the liner wall temperatures in the range of 500 °C for lower air/fuel ratio and 300 °C for higher air/fuel ratio certainly ensures safe and reliable operation of this combustion chamber.


2006 ◽  
Author(s):  
R. Senthil ◽  
N. V. Mahalakshmi

Swirl with bluff body wake in jets finds application in gas turbine engines, turbo machinery etc. to strengthen the recirculation region, improve combustion efficiency, enhance flame stabilization, improve fuel air mixing and blow off limits and lower pollutant formation. This paper discusses the combined effect of swirl and rotating bluff body wake in circular jets. The flow pattern of the swirl jet has been studied in the near vicinity of the jet exit for different inlet high Reynolds numbers (only for which the recirculation effect is beneficial), critical swirl angle (30 degree-similar to what is employed in industrial furnaces and burners), and a constant blockage ratio of the bluff body at eight different axial positions in the recirculation zone. Reynolds stresses, mean axial and tangential velocities, turbulent intensities, turbulent kinetic energy are measured and compared for the bluff body rotating and non-rotating cases. A DANTEC Dynamics make constant temperature anemometer with X-probe has been used to measure mean and turbulence parameters.


Author(s):  
Enrico Conte ◽  
Konstantinos Boulouchos

Experimental investigations were carried out to assess the use of hydrogen in a gasoline direct injection (GDI) engine. Injection of small amounts of hydrogen (up to 27% on energy basis) in the intake port creates a reactive homogeneous background for the direct injection of gasoline in the cylinder. In this way, it is possible to operate the engine with high exhaust gas recirculation (EGR) rates and, in certain conditions, to delay the ignition timing as compared to standard GDI operation, in order to reduce NOx and HC emissions to very low levels and possibly soot emissions. The results confirmed that high EGR rates can be achieved and NOx and HC emissions reduced, showed significant advantage in terms of combustion efficiency and gave unexpected results relative to the delaying of ignition, which only partly confirmed the expected behavior. A realistic application would make use of hydrogen-containing reformer gas produced on board the vehicle, but safety restrictions did not allow using carbon monoxide in the test facility. Thus, pure hydrogen was used for a best-case investigation. The expected difference in the use of the two gases is briefly discussed.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3562
Author(s):  
Fekadu Mosisa Wako ◽  
Gianmaria Pio ◽  
Ernesto Salzano

The need for lowering the environmental impacts has incentivized the investigation of biomass and biofuels as possible alternative sources for energy supply. Among the others, oxygenated bio-derived molecules such as alcohols, esters, acids, aldehydes, and furans are attractive substances as chemical feedstock and for sustainable energy production. Indeed, the presence of oxygen atoms limits the production of aromatic compounds, improves combustion efficiency (thus heat production) and alleviates the formation of carbon soot. On the other hand, the variability of their composition has represented one of the major challenges for the complete characterization of combustion behaviour. This work gives an overview of the current understanding of the detailed chemical mechanisms, as well as experimental investigations characterizing the combustion process of these species, with an emphasis on the laminar burning velocity and the ignition delay time. From the review, the common intermediates for the most relevant functional groups and combustion of biofuels were identified. The gathered information can be intended for the sake of core mechanism generation.


Author(s):  
V. Hariram ◽  
S. Seralathan ◽  
M. Rajasekaran ◽  
M. Dinesh Kumar ◽  
S. Padmanabhan

Compression ignition engines are widely used due to their lower energy consumption and enhanced combustion efficiency. In this experimental investigation, the feasibility of fuelling a single cylinder 4 stroke direct injection compression ignition engine with methyl esters of palmkernel (PME) oil along with various fractions of aluminium oxide nano particles (ANOP) were analysed. Two stage transesterification process was adopted to prepare PME. PME20 blend was formulated and fused using high speed homogenizer with varying proportions of AONP as 25 ppm, 50 ppm and 100 ppm in the presence of hexadecyl trimethyl ammonium bromide as surfactant. The experimental investigations were conducted at rated power of 3.5kW at 1500rpm. It was noticed that supplementation of AONP affected the ignition delay significantly favouring enhanced combustion efficiency. The rate of heat release and in-cylinder pressure was substantially increased with notable reduction in ignition delay. Addition of AONP showed an increase in brake thermal efficiency and exhaust gas temperature with diminution in brake specific energy consumption. The unburned hydrocarbons, carbon monoxide and smoke density decreased sharply with an upsurge in NOx. Increase in AONP concentration up-to 100 ppm with PME20 was found to give better combustion and performance characteristics.


Author(s):  
Enrico Conte ◽  
Konstantinos Boulouchos

Experimental investigations were carried out to assess the use of hydrogen in a Gasoline Direct Injection (GDI) engine. Injection of small amounts of hydrogen (up to 27% on energy basis) in the intake port creates a reactive homogeneous background for the direct injection of gasoline in the cylinder. In this way, it is possible to operate the engine with high EGR rates and, in certain conditions, to delay the ignition timing as compared to standard GDI operation, in order to reduce NOx and HC emissions to very low levels and possibly soot emissions. The results confirmed that high EGR rates can be achieved and NOx and HC emissions reduced, showed significant advantage in terms of combustion efficiency and gave unexpected results relative to the delaying of ignition, which only partly confirmed the expected behavior. A realistic application would make use of hydrogen-containing reformer gas produced on board the vehicle, but safety restrictions did not allow using carbon monoxide in the test facility. Thus pure hydrogen was used for a best-case investigation. The expected difference in the use of the two gases is briefly discussed.


2000 ◽  
Vol 21 (3) ◽  
pp. 322-328 ◽  
Author(s):  
T ZAHNERT ◽  
K HUTTENBRINK ◽  
D MURBE ◽  
M BORNITZ

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